Merge remote-tracking branch 'origin/master' into self-hosted-incremental-compilation

80 files changed, 1505 insertions, 1052 deletions

diff --git a/lib/std/ascii.zig b/lib/std/ascii.zig
index 8bd959b46d..102be18bec 100644
--- a/lib/std/ascii.zig
+++ b/lib/std/ascii.zig
@@ -227,6 +227,8 @@ test "ascii character classes" {
     testing.expect(isSpace(' '));
 }
 
+/// Allocates a lower case copy of `ascii_string`.
+/// Caller owns returned string and must free with `allocator`.
 pub fn allocLowerString(allocator: *std.mem.Allocator, ascii_string: []const u8) ![]u8 {
     const result = try allocator.alloc(u8, ascii_string.len);
     for (result) |*c, i| {
@@ -241,6 +243,23 @@ test "allocLowerString" {
     std.testing.expect(std.mem.eql(u8, "abcdefghijklmnopqrst0234+💩!", result));
 }
 
+/// Allocates an upper case copy of `ascii_string`.
+/// Caller owns returned string and must free with `allocator`.
+pub fn allocUpperString(allocator: *std.mem.Allocator, ascii_string: []const u8) ![]u8 {
+    const result = try allocator.alloc(u8, ascii_string.len);
+    for (result) |*c, i| {
+        c.* = toUpper(ascii_string[i]);
+    }
+    return result;
+}
+
+test "allocUpperString" {
+    const result = try allocUpperString(std.testing.allocator, "aBcDeFgHiJkLmNOPqrst0234+💩!");
+    defer std.testing.allocator.free(result);
+    std.testing.expect(std.mem.eql(u8, "ABCDEFGHIJKLMNOPQRST0234+💩!", result));
+}
+
+/// Compares strings `a` and `b` case insensitively and returns whether they are equal.
 pub fn eqlIgnoreCase(a: []const u8, b: []const u8) bool {
     if (a.len != b.len) return false;
     for (a) |a_c, i| {
@@ -255,7 +274,7 @@ test "eqlIgnoreCase" {
     std.testing.expect(!eqlIgnoreCase("hElLo!", "helro!"));
 }
 
-/// Finds `substr` in `container`, starting at `start_index`.
+/// Finds `substr` in `container`, ignoring case, starting at `start_index`.
 /// TODO boyer-moore algorithm
 pub fn indexOfIgnoreCasePos(container: []const u8, start_index: usize, substr: []const u8) ?usize {
     if (substr.len > container.len) return null;
@@ -268,7 +287,7 @@ pub fn indexOfIgnoreCasePos(container: []const u8, start_index: usize, substr: [
     return null;
 }
 
-/// Finds `substr` in `container`, starting at `start_index`.
+/// Finds `substr` in `container`, ignoring case, starting at index 0.
 pub fn indexOfIgnoreCase(container: []const u8, substr: []const u8) ?usize {
     return indexOfIgnoreCasePos(container, 0, substr);
 }
diff --git a/lib/std/build.zig b/lib/std/build.zig
index 85a65393ec..67f2af1047 100644
--- a/lib/std/build.zig
+++ b/lib/std/build.zig
@@ -284,11 +284,11 @@ pub const Builder = struct {
         return run_step;
     }
 
-    fn dupe(self: *Builder, bytes: []const u8) []u8 {
+    pub fn dupe(self: *Builder, bytes: []const u8) []u8 {
         return mem.dupe(self.allocator, u8, bytes) catch unreachable;
     }
 
-    fn dupePath(self: *Builder, bytes: []const u8) []u8 {
+    pub fn dupePath(self: *Builder, bytes: []const u8) []u8 {
         const the_copy = self.dupe(bytes);
         for (the_copy) |*byte| {
             switch (byte.*) {
@@ -717,7 +717,7 @@ pub const Builder = struct {
         return self.invalid_user_input;
     }
 
-    fn spawnChild(self: *Builder, argv: []const []const u8) !void {
+    pub fn spawnChild(self: *Builder, argv: []const []const u8) !void {
         return self.spawnChildEnvMap(null, self.env_map, argv);
     }
 
@@ -843,7 +843,7 @@ pub const Builder = struct {
         }) catch unreachable;
     }
 
-    fn updateFile(self: *Builder, source_path: []const u8, dest_path: []const u8) !void {
+    pub fn updateFile(self: *Builder, source_path: []const u8, dest_path: []const u8) !void {
         if (self.verbose) {
             warn("cp {} {} ", .{ source_path, dest_path });
         }
@@ -855,7 +855,7 @@ pub const Builder = struct {
         };
     }
 
-    fn pathFromRoot(self: *Builder, rel_path: []const u8) []u8 {
+    pub fn pathFromRoot(self: *Builder, rel_path: []const u8) []u8 {
         return fs.path.resolve(self.allocator, &[_][]const u8{ self.build_root, rel_path }) catch unreachable;
     }
 
@@ -985,7 +985,7 @@ pub const Builder = struct {
         self.search_prefixes.append(search_prefix) catch unreachable;
     }
 
-    fn getInstallPath(self: *Builder, dir: InstallDir, dest_rel_path: []const u8) []const u8 {
+    pub fn getInstallPath(self: *Builder, dir: InstallDir, dest_rel_path: []const u8) []const u8 {
         const base_dir = switch (dir) {
             .Prefix => self.install_path,
             .Bin => self.exe_dir,
@@ -1132,6 +1132,7 @@ pub const LibExeObjStep = struct {
     name_prefix: []const u8,
     filter: ?[]const u8,
     single_threaded: bool,
+    test_evented_io: bool = false,
     code_model: builtin.CodeModel = .default,
 
     root_src: ?FileSource,
@@ -1864,6 +1865,10 @@ pub const LibExeObjStep = struct {
             try zig_args.append(filter);
         }
 
+        if (self.test_evented_io) {
+            try zig_args.append("--test-evented-io");
+        }
+
         if (self.name_prefix.len != 0) {
             try zig_args.append("--test-name-prefix");
             try zig_args.append(self.name_prefix);
diff --git a/lib/std/c.zig b/lib/std/c.zig
index 9f1114b9c1..0f166b7e59 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -217,7 +217,7 @@ pub extern "c" fn utimes(path: [*:0]const u8, times: *[2]timeval) c_int;
 pub extern "c" fn utimensat(dirfd: fd_t, pathname: [*:0]const u8, times: *[2]timespec, flags: u32) c_int;
 pub extern "c" fn futimens(fd: fd_t, times: *const [2]timespec) c_int;
 
-pub extern "c" fn pthread_create(noalias newthread: *pthread_t, noalias attr: ?*const pthread_attr_t, start_routine: extern fn (?*c_void) ?*c_void, noalias arg: ?*c_void) c_int;
+pub extern "c" fn pthread_create(noalias newthread: *pthread_t, noalias attr: ?*const pthread_attr_t, start_routine: fn (?*c_void) callconv(.C) ?*c_void, noalias arg: ?*c_void) c_int;
 pub extern "c" fn pthread_attr_init(attr: *pthread_attr_t) c_int;
 pub extern "c" fn pthread_attr_setstack(attr: *pthread_attr_t, stackaddr: *c_void, stacksize: usize) c_int;
 pub extern "c" fn pthread_attr_setguardsize(attr: *pthread_attr_t, guardsize: usize) c_int;
diff --git a/lib/std/c/dragonfly.zig b/lib/std/c/dragonfly.zig
index a271b2e869..0c859018be 100644
--- a/lib/std/c/dragonfly.zig
+++ b/lib/std/c/dragonfly.zig
@@ -9,7 +9,7 @@ pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) usize;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
 pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) isize;
 
-pub const dl_iterate_phdr_callback = extern fn (info: *dl_phdr_info, size: usize, data: ?*c_void) c_int;
+pub const dl_iterate_phdr_callback = fn (info: *dl_phdr_info, size: usize, data: ?*c_void) callconv(.C) c_int;
 pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*c_void) c_int;
 
 pub const pthread_mutex_t = extern struct {
diff --git a/lib/std/c/freebsd.zig b/lib/std/c/freebsd.zig
index 3a0634dbb7..ea52c05f0b 100644
--- a/lib/std/c/freebsd.zig
+++ b/lib/std/c/freebsd.zig
@@ -24,7 +24,7 @@ pub extern "c" fn sendfile(
     flags: u32,
 ) c_int;
 
-pub const dl_iterate_phdr_callback = extern fn (info: *dl_phdr_info, size: usize, data: ?*c_void) c_int;
+pub const dl_iterate_phdr_callback = fn (info: *dl_phdr_info, size: usize, data: ?*c_void) callconv(.C) c_int;
 pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*c_void) c_int;
 
 pub const pthread_mutex_t = extern struct {
diff --git a/lib/std/c/linux.zig b/lib/std/c/linux.zig
index 1da0db57d6..4ceeb5a773 100644
--- a/lib/std/c/linux.zig
+++ b/lib/std/c/linux.zig
@@ -75,7 +75,7 @@ pub extern "c" fn inotify_add_watch(fd: fd_t, pathname: [*]const u8, mask: u32)
 /// See std.elf for constants for this
 pub extern "c" fn getauxval(__type: c_ulong) c_ulong;
 
-pub const dl_iterate_phdr_callback = extern fn (info: *dl_phdr_info, size: usize, data: ?*c_void) c_int;
+pub const dl_iterate_phdr_callback = fn (info: *dl_phdr_info, size: usize, data: ?*c_void) callconv(.C) c_int;
 pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*c_void) c_int;
 
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
diff --git a/lib/std/c/netbsd.zig b/lib/std/c/netbsd.zig
index 20960b3f77..31adbb1f59 100644
--- a/lib/std/c/netbsd.zig
+++ b/lib/std/c/netbsd.zig
@@ -6,7 +6,7 @@ usingnamespace std.c;
 extern "c" fn __errno() *c_int;
 pub const _errno = __errno;
 
-pub const dl_iterate_phdr_callback = extern fn (info: *dl_phdr_info, size: usize, data: ?*c_void) c_int;
+pub const dl_iterate_phdr_callback = fn (info: *dl_phdr_info, size: usize, data: ?*c_void) callconv(.C) c_int;
 pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*c_void) c_int;
 
 pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
diff --git a/lib/std/crypto/blake3.zig b/lib/std/crypto/blake3.zig
index 7c79ffcf55..08479d65a5 100644
--- a/lib/std/crypto/blake3.zig
+++ b/lib/std/crypto/blake3.zig
@@ -338,7 +338,7 @@ pub const Blake3 = struct {
     }
 
     // Section 5.1.2 of the BLAKE3 spec explains this algorithm in more detail.
-    fn add_chunk_chaining_value(self: *Blake3, new_cv: [8]u32, total_chunks: u64) void {
+    fn add_chunk_chaining_value(self: *Blake3, first_cv: [8]u32, total_chunks: u64) void {
         // This chunk might complete some subtrees. For each completed subtree,
         // its left child will be the current top entry in the CV stack, and
         // its right child will be the current value of `new_cv`. Pop each left
@@ -346,6 +346,7 @@ pub const Blake3 = struct {
         // with the result. After all these merges, push the final value of
         // `new_cv` onto the stack. The number of completed subtrees is given
         // by the number of trailing 0-bits in the new total number of chunks.
+        var new_cv = first_cv;
         var chunk_counter = total_chunks;
         while (chunk_counter & 1 == 0) {
             new_cv = parent_cv(self.pop_cv(), new_cv, self.key, self.flags);
diff --git a/lib/std/debug.zig b/lib/std/debug.zig
index df84a8bbcb..3e52770932 100644
--- a/lib/std/debug.zig
+++ b/lib/std/debug.zig
@@ -62,7 +62,7 @@ pub fn warn(comptime fmt: []const u8, args: var) void {
     const held = stderr_mutex.acquire();
     defer held.release();
     const stderr = getStderrStream();
-    noasync stderr.print(fmt, args) catch return;
+    nosuspend stderr.print(fmt, args) catch return;
 }
 
 pub fn getStderrStream() *File.OutStream {
@@ -112,7 +112,7 @@ pub fn detectTTYConfig() TTY.Config {
 /// Tries to print the current stack trace to stderr, unbuffered, and ignores any error returned.
 /// TODO multithreaded awareness
 pub fn dumpCurrentStackTrace(start_addr: ?usize) void {
-    noasync {
+    nosuspend {
         const stderr = getStderrStream();
         if (builtin.strip_debug_info) {
             stderr.print("Unable to dump stack trace: debug info stripped\n", .{}) catch return;
@@ -133,7 +133,7 @@ pub fn dumpCurrentStackTrace(start_addr: ?usize) void {
 /// unbuffered, and ignores any error returned.
 /// TODO multithreaded awareness
 pub fn dumpStackTraceFromBase(bp: usize, ip: usize) void {
-    noasync {
+    nosuspend {
         const stderr = getStderrStream();
         if (builtin.strip_debug_info) {
             stderr.print("Unable to dump stack trace: debug info stripped\n", .{}) catch return;
@@ -203,7 +203,7 @@ pub fn captureStackTrace(first_address: ?usize, stack_trace: *builtin.StackTrace
 /// Tries to print a stack trace to stderr, unbuffered, and ignores any error returned.
 /// TODO multithreaded awareness
 pub fn dumpStackTrace(stack_trace: builtin.StackTrace) void {
-    noasync {
+    nosuspend {
         const stderr = getStderrStream();
         if (builtin.strip_debug_info) {
             stderr.print("Unable to dump stack trace: debug info stripped\n", .{}) catch return;
@@ -261,7 +261,7 @@ pub fn panicExtra(trace: ?*const builtin.StackTrace, first_trace_addr: ?usize, c
         resetSegfaultHandler();
     }
 
-    noasync switch (panic_stage) {
+    nosuspend switch (panic_stage) {
         0 => {
             panic_stage = 1;
 
@@ -357,7 +357,7 @@ pub const StackIterator = struct {
     else
         0;
 
-    fn next(self: *StackIterator) ?usize {
+    pub fn next(self: *StackIterator) ?usize {
         var address = self.next_internal() orelse return null;
 
         if (self.first_address) |first_address| {
@@ -447,7 +447,7 @@ pub const TTY = struct {
         windows_api,
 
         fn setColor(conf: Config, out_stream: var, color: Color) void {
-            noasync switch (conf) {
+            nosuspend switch (conf) {
                 .no_color => return,
                 .escape_codes => switch (color) {
                     .Red => out_stream.writeAll(RED) catch return,
@@ -604,7 +604,7 @@ fn printLineInfo(
     tty_config: TTY.Config,
     comptime printLineFromFile: var,
 ) !void {
-    noasync {
+    nosuspend {
         tty_config.setColor(out_stream, .White);
 
         if (line_info) |*li| {
@@ -651,7 +651,7 @@ pub const OpenSelfDebugInfoError = error{
 
 /// TODO resources https://github.com/ziglang/zig/issues/4353
 pub fn openSelfDebugInfo(allocator: *mem.Allocator) anyerror!DebugInfo {
-    noasync {
+    nosuspend {
         if (builtin.strip_debug_info)
             return error.MissingDebugInfo;
         if (@hasDecl(root, "os") and @hasDecl(root.os, "debug") and @hasDecl(root.os.debug, "openSelfDebugInfo")) {
@@ -672,7 +672,7 @@ pub fn openSelfDebugInfo(allocator: *mem.Allocator) anyerror!DebugInfo {
 
 /// TODO resources https://github.com/ziglang/zig/issues/4353
 fn openCoffDebugInfo(allocator: *mem.Allocator, coff_file_path: [:0]const u16) !ModuleDebugInfo {
-    noasync {
+    nosuspend {
         const coff_file = try std.fs.openFileAbsoluteW(coff_file_path, .{ .intended_io_mode = .blocking });
         errdefer coff_file.close();
 
@@ -853,7 +853,7 @@ fn chopSlice(ptr: []const u8, offset: u64, size: u64) ![]const u8 {
 
 /// TODO resources https://github.com/ziglang/zig/issues/4353
 pub fn openElfDebugInfo(allocator: *mem.Allocator, elf_file_path: []const u8) !ModuleDebugInfo {
-    noasync {
+    nosuspend {
         const mapped_mem = try mapWholeFile(elf_file_path);
         const hdr = @ptrCast(*const elf.Ehdr, &mapped_mem[0]);
         if (!mem.eql(u8, hdr.e_ident[0..4], "\x7fELF")) return error.InvalidElfMagic;
@@ -1056,7 +1056,7 @@ const MachoSymbol = struct {
 };
 
 fn mapWholeFile(path: []const u8) ![]align(mem.page_size) const u8 {
-    noasync {
+    nosuspend {
         const file = try fs.cwd().openFile(path, .{ .intended_io_mode = .blocking });
         defer file.close();
 
@@ -1418,7 +1418,7 @@ pub const ModuleDebugInfo = switch (builtin.os.tag) {
         }
 
         fn getSymbolAtAddress(self: *@This(), address: usize) !SymbolInfo {
-            noasync {
+            nosuspend {
                 // Translate the VA into an address into this object
                 const relocated_address = address - self.base_address;
                 assert(relocated_address >= 0x100000000);
@@ -1643,14 +1643,14 @@ pub const ModuleDebugInfo = switch (builtin.os.tag) {
             // Translate the VA into an address into this object
             const relocated_address = address - self.base_address;
 
-            if (noasync self.dwarf.findCompileUnit(relocated_address)) |compile_unit| {
+            if (nosuspend self.dwarf.findCompileUnit(relocated_address)) |compile_unit| {
                 return SymbolInfo{
-                    .symbol_name = noasync self.dwarf.getSymbolName(relocated_address) orelse "???",
+                    .symbol_name = nosuspend self.dwarf.getSymbolName(relocated_address) orelse "???",
                     .compile_unit_name = compile_unit.die.getAttrString(&self.dwarf, DW.AT_name) catch |err| switch (err) {
                         error.MissingDebugInfo, error.InvalidDebugInfo => "???",
                         else => return err,
                     },
-                    .line_info = noasync self.dwarf.getLineNumberInfo(compile_unit.*, relocated_address) catch |err| switch (err) {
+                    .line_info = nosuspend self.dwarf.getLineNumberInfo(compile_unit.*, relocated_address) catch |err| switch (err) {
                         error.MissingDebugInfo, error.InvalidDebugInfo => null,
                         else => return err,
                     },
diff --git a/lib/std/dwarf.zig b/lib/std/dwarf.zig
index 42139876bb..ebb4c096f8 100644
--- a/lib/std/dwarf.zig
+++ b/lib/std/dwarf.zig
@@ -121,7 +121,7 @@ const Die = struct {
         };
     }
 
-    fn getAttrString(self: *const Die, di: *DwarfInfo, id: u64) ![]const u8 {
+    pub fn getAttrString(self: *const Die, di: *DwarfInfo, id: u64) ![]const u8 {
         const form_value = self.getAttr(id) orelse return error.MissingDebugInfo;
         return switch (form_value.*) {
             FormValue.String => |value| value,
@@ -248,17 +248,17 @@ fn readUnitLength(in_stream: var, endian: builtin.Endian, is_64: *bool) !u64 {
     }
 }
 
-// TODO the noasyncs here are workarounds
+// TODO the nosuspends here are workarounds
 fn readAllocBytes(allocator: *mem.Allocator, in_stream: var, size: usize) ![]u8 {
     const buf = try allocator.alloc(u8, size);
     errdefer allocator.free(buf);
-    if ((try noasync in_stream.read(buf)) < size) return error.EndOfFile;
+    if ((try nosuspend in_stream.read(buf)) < size) return error.EndOfFile;
     return buf;
 }
 
-// TODO the noasyncs here are workarounds
+// TODO the nosuspends here are workarounds
 fn readAddress(in_stream: var, endian: builtin.Endian, is_64: bool) !u64 {
-    return noasync if (is_64)
+    return nosuspend if (is_64)
         try in_stream.readInt(u64, endian)
     else
         @as(u64, try in_stream.readInt(u32, endian));
@@ -269,29 +269,29 @@ fn parseFormValueBlockLen(allocator: *mem.Allocator, in_stream: var, size: usize
     return FormValue{ .Block = buf };
 }
 
-// TODO the noasyncs here are workarounds
+// TODO the nosuspends here are workarounds
 fn parseFormValueBlock(allocator: *mem.Allocator, in_stream: var, endian: builtin.Endian, size: usize) !FormValue {
-    const block_len = try noasync in_stream.readVarInt(usize, endian, size);
+    const block_len = try nosuspend in_stream.readVarInt(usize, endian, size);
     return parseFormValueBlockLen(allocator, in_stream, block_len);
 }
 
 fn parseFormValueConstant(allocator: *mem.Allocator, in_stream: var, signed: bool, endian: builtin.Endian, comptime size: i32) !FormValue {
     // TODO: Please forgive me, I've worked around zig not properly spilling some intermediate values here.
-    // `noasync` should be removed from all the function calls once it is fixed.
+    // `nosuspend` should be removed from all the function calls once it is fixed.
     return FormValue{
         .Const = Constant{
             .signed = signed,
             .payload = switch (size) {
-                1 => try noasync in_stream.readInt(u8, endian),
-                2 => try noasync in_stream.readInt(u16, endian),
-                4 => try noasync in_stream.readInt(u32, endian),
-                8 => try noasync in_stream.readInt(u64, endian),
+                1 => try nosuspend in_stream.readInt(u8, endian),
+                2 => try nosuspend in_stream.readInt(u16, endian),
+                4 => try nosuspend in_stream.readInt(u32, endian),
+                8 => try nosuspend in_stream.readInt(u64, endian),
                 -1 => blk: {
                     if (signed) {
-                        const x = try noasync leb.readILEB128(i64, in_stream);
+                        const x = try nosuspend leb.readILEB128(i64, in_stream);
                         break :blk @bitCast(u64, x);
                     } else {
-                        const x = try noasync leb.readULEB128(u64, in_stream);
+                        const x = try nosuspend leb.readULEB128(u64, in_stream);
                         break :blk x;
                     }
                 },
@@ -301,21 +301,21 @@ fn parseFormValueConstant(allocator: *mem.Allocator, in_stream: var, signed: boo
     };
 }
 
-// TODO the noasyncs here are workarounds
+// TODO the nosuspends here are workarounds
 fn parseFormValueRef(allocator: *mem.Allocator, in_stream: var, endian: builtin.Endian, size: i32) !FormValue {
     return FormValue{
         .Ref = switch (size) {
-            1 => try noasync in_stream.readInt(u8, endian),
-            2 => try noasync in_stream.readInt(u16, endian),
-            4 => try noasync in_stream.readInt(u32, endian),
-            8 => try noasync in_stream.readInt(u64, endian),
-            -1 => try noasync leb.readULEB128(u64, in_stream),
+            1 => try nosuspend in_stream.readInt(u8, endian),
+            2 => try nosuspend in_stream.readInt(u16, endian),
+            4 => try nosuspend in_stream.readInt(u32, endian),
+            8 => try nosuspend in_stream.readInt(u64, endian),
+            -1 => try nosuspend leb.readULEB128(u64, in_stream),
             else => unreachable,
         },
     };
 }
 
-// TODO the noasyncs here are workarounds
+// TODO the nosuspends here are workarounds
 fn parseFormValue(allocator: *mem.Allocator, in_stream: var, form_id: u64, endian: builtin.Endian, is_64: bool) anyerror!FormValue {
     return switch (form_id) {
         FORM_addr => FormValue{ .Address = try readAddress(in_stream, endian, @sizeOf(usize) == 8) },
@@ -323,7 +323,7 @@ fn parseFormValue(allocator: *mem.Allocator, in_stream: var, form_id: u64, endia
         FORM_block2 => parseFormValueBlock(allocator, in_stream, endian, 2),
         FORM_block4 => parseFormValueBlock(allocator, in_stream, endian, 4),
         FORM_block => x: {
-            const block_len = try noasync leb.readULEB128(usize, in_stream);
+            const block_len = try nosuspend leb.readULEB128(usize, in_stream);
             return parseFormValueBlockLen(allocator, in_stream, block_len);
         },
         FORM_data1 => parseFormValueConstant(allocator, in_stream, false, endian, 1),
@@ -335,11 +335,11 @@ fn parseFormValue(allocator: *mem.Allocator, in_stream: var, form_id: u64, endia
             return parseFormValueConstant(allocator, in_stream, signed, endian, -1);
         },
         FORM_exprloc => {
-            const size = try noasync leb.readULEB128(usize, in_stream);
+            const size = try nosuspend leb.readULEB128(usize, in_stream);
             const buf = try readAllocBytes(allocator, in_stream, size);
             return FormValue{ .ExprLoc = buf };
         },
-        FORM_flag => FormValue{ .Flag = (try noasync in_stream.readByte()) != 0 },
+        FORM_flag => FormValue{ .Flag = (try nosuspend in_stream.readByte()) != 0 },
         FORM_flag_present => FormValue{ .Flag = true },
         FORM_sec_offset => FormValue{ .SecOffset = try readAddress(in_stream, endian, is_64) },
 
@@ -350,12 +350,12 @@ fn parseFormValue(allocator: *mem.Allocator, in_stream: var, form_id: u64, endia
         FORM_ref_udata => parseFormValueRef(allocator, in_stream, endian, -1),
 
         FORM_ref_addr => FormValue{ .RefAddr = try readAddress(in_stream, endian, is_64) },
-        FORM_ref_sig8 => FormValue{ .Ref = try noasync in_stream.readInt(u64, endian) },
+        FORM_ref_sig8 => FormValue{ .Ref = try nosuspend in_stream.readInt(u64, endian) },
 
         FORM_string => FormValue{ .String = try in_stream.readUntilDelimiterAlloc(allocator, 0, math.maxInt(usize)) },
         FORM_strp => FormValue{ .StrPtr = try readAddress(in_stream, endian, is_64) },
         FORM_indirect => {
-            const child_form_id = try noasync leb.readULEB128(u64, in_stream);
+            const child_form_id = try nosuspend leb.readULEB128(u64, in_stream);
             const F = @TypeOf(async parseFormValue(allocator, in_stream, child_form_id, endian, is_64));
             var frame = try allocator.create(F);
             defer allocator.destroy(frame);
@@ -389,7 +389,7 @@ pub const DwarfInfo = struct {
         return self.abbrev_table_list.allocator;
     }
 
-    fn getSymbolName(di: *DwarfInfo, address: u64) ?[]const u8 {
+    pub fn getSymbolName(di: *DwarfInfo, address: u64) ?[]const u8 {
         for (di.func_list.span()) |*func| {
             if (func.pc_range) |range| {
                 if (address >= range.start and address < range.end) {
@@ -578,7 +578,7 @@ pub const DwarfInfo = struct {
         }
     }
 
-    fn findCompileUnit(di: *DwarfInfo, target_address: u64) !*const CompileUnit {
+    pub fn findCompileUnit(di: *DwarfInfo, target_address: u64) !*const CompileUnit {
         for (di.compile_unit_list.span()) |*compile_unit| {
             if (compile_unit.pc_range) |range| {
                 if (target_address >= range.start and target_address < range.end) return compile_unit;
@@ -690,7 +690,7 @@ pub const DwarfInfo = struct {
         return result;
     }
 
-    fn getLineNumberInfo(di: *DwarfInfo, compile_unit: CompileUnit, target_address: usize) !debug.LineInfo {
+    pub fn getLineNumberInfo(di: *DwarfInfo, compile_unit: CompileUnit, target_address: usize) !debug.LineInfo {
         var stream = io.fixedBufferStream(di.debug_line);
         const in = &stream.inStream();
         const seekable = &stream.seekableStream();
diff --git a/lib/std/dynamic_library.zig b/lib/std/dynamic_library.zig
index 70e26cc71c..65c65292bc 100644
--- a/lib/std/dynamic_library.zig
+++ b/lib/std/dynamic_library.zig
@@ -33,11 +33,11 @@ const LinkMap = extern struct {
     pub const Iterator = struct {
         current: ?*LinkMap,
 
-        fn end(self: *Iterator) bool {
+        pub fn end(self: *Iterator) bool {
             return self.current == null;
         }
 
-        fn next(self: *Iterator) ?*LinkMap {
+        pub fn next(self: *Iterator) ?*LinkMap {
             if (self.current) |it| {
                 self.current = it.l_next;
                 return it;
diff --git a/lib/std/elf.zig b/lib/std/elf.zig
index 7b415f675a..f02cb33969 100644
--- a/lib/std/elf.zig
+++ b/lib/std/elf.zig
@@ -548,6 +548,7 @@ fn preadNoEof(file: std.fs.File, buf: []u8, offset: u64) !void {
             error.BrokenPipe => return error.UnableToReadElfFile,
             error.Unseekable => return error.UnableToReadElfFile,
             error.ConnectionResetByPeer => return error.UnableToReadElfFile,
+            error.ConnectionTimedOut => return error.UnableToReadElfFile,
             error.InputOutput => return error.FileSystem,
             error.Unexpected => return error.Unexpected,
             error.WouldBlock => return error.Unexpected,
diff --git a/lib/std/event/batch.zig b/lib/std/event/batch.zig
index af59b32490..9c424fcd2c 100644
--- a/lib/std/event/batch.zig
+++ b/lib/std/event/batch.zig
@@ -21,7 +21,7 @@ pub fn Batch(
         /// usual recommended option for this parameter.
         auto_async,
 
-        /// Always uses the `noasync` keyword when using `await` on the jobs,
+        /// Always uses the `nosuspend` keyword when using `await` on the jobs,
         /// making `add` and `wait` non-async functions. Asserts that the jobs do not suspend.
         never_async,
 
@@ -75,7 +75,7 @@ pub fn Batch(
             const job = &self.jobs[self.next_job_index];
             self.next_job_index = (self.next_job_index + 1) % max_jobs;
             if (job.frame) |existing| {
-                job.result = if (async_ok) await existing else noasync await existing;
+                job.result = if (async_ok) await existing else nosuspend await existing;
                 if (CollectedResult != void) {
                     job.result catch |err| {
                         self.collected_result = err;
@@ -94,7 +94,7 @@ pub fn Batch(
         /// a time, however, it need not be the same thread.
         pub fn wait(self: *Self) CollectedResult {
             for (self.jobs) |*job| if (job.frame) |f| {
-                job.result = if (async_ok) await f else noasync await f;
+                job.result = if (async_ok) await f else nosuspend await f;
                 if (CollectedResult != void) {
                     job.result catch |err| {
                         self.collected_result = err;
diff --git a/lib/std/event/channel.zig b/lib/std/event/channel.zig
index 83c77bcac5..5aef0bb3ba 100644
--- a/lib/std/event/channel.zig
+++ b/lib/std/event/channel.zig
@@ -105,7 +105,7 @@ pub fn Channel(comptime T: type) type {
 
         /// await this function to get an item from the channel. If the buffer is empty, the frame will
         /// complete when the next item is put in the channel.
-        pub async fn get(self: *SelfChannel) T {
+        pub fn get(self: *SelfChannel) callconv(.Async) T {
             // TODO https://github.com/ziglang/zig/issues/2765
             var result: T = undefined;
             var my_tick_node = Loop.NextTickNode.init(@frame());
@@ -305,8 +305,7 @@ test "std.event.Channel wraparound" {
     channel.put(7);
     testing.expectEqual(@as(i32, 7), channel.get());
 }
-
-async fn testChannelGetter(channel: *Channel(i32)) void {
+fn testChannelGetter(channel: *Channel(i32)) callconv(.Async) void {
     const value1 = channel.get();
     testing.expect(value1 == 1234);
 
@@ -321,12 +320,10 @@ async fn testChannelGetter(channel: *Channel(i32)) void {
     testing.expect(value4.? == 4444);
     await last_put;
 }
-
-async fn testChannelPutter(channel: *Channel(i32)) void {
+fn testChannelPutter(channel: *Channel(i32)) callconv(.Async) void {
     channel.put(1234);
     channel.put(4567);
 }
-
-async fn testPut(channel: *Channel(i32), value: i32) void {
+fn testPut(channel: *Channel(i32), value: i32) callconv(.Async) void {
     channel.put(value);
 }
diff --git a/lib/std/event/future.zig b/lib/std/event/future.zig
index 51a63e90ee..5de22c574c 100644
--- a/lib/std/event/future.zig
+++ b/lib/std/event/future.zig
@@ -34,7 +34,7 @@ pub fn Future(comptime T: type) type {
         /// Obtain the value. If it's not available, wait until it becomes
         /// available.
         /// Thread-safe.
-        pub async fn get(self: *Self) *T {
+        pub fn get(self: *Self) callconv(.Async) *T {
             if (@atomicLoad(Available, &self.available, .SeqCst) == .Finished) {
                 return &self.data;
             }
@@ -59,7 +59,7 @@ pub fn Future(comptime T: type) type {
         /// should start working on the data.
         /// It's not required to call start() before resolve() but it can be useful since
         /// this method is thread-safe.
-        pub async fn start(self: *Self) ?*T {
+        pub fn start(self: *Self) callconv(.Async) ?*T {
             const state = @cmpxchgStrong(Available, &self.available, .NotStarted, .Started, .SeqCst, .SeqCst) orelse return null;
             switch (state) {
                 .Started => {
diff --git a/lib/std/event/group.zig b/lib/std/event/group.zig
index 5eebb7ffbc..155a9486b7 100644
--- a/lib/std/event/group.zig
+++ b/lib/std/event/group.zig
@@ -84,7 +84,7 @@ pub fn Group(comptime ReturnType: type) type {
         /// Wait for all the calls and promises of the group to complete.
         /// Thread-safe.
         /// Safe to call any number of times.
-        pub async fn wait(self: *Self) ReturnType {
+        pub fn wait(self: *Self) callconv(.Async) ReturnType {
             const held = self.lock.acquire();
             defer held.release();
 
@@ -127,8 +127,7 @@ test "std.event.Group" {
 
     const handle = async testGroup(std.heap.page_allocator);
 }
-
-async fn testGroup(allocator: *Allocator) void {
+fn testGroup(allocator: *Allocator) callconv(.Async) void {
     var count: usize = 0;
     var group = Group(void).init(allocator);
     var sleep_a_little_frame = async sleepALittle(&count);
@@ -145,20 +144,17 @@ async fn testGroup(allocator: *Allocator) void {
     another.add(&something_that_fails_frame) catch @panic("memory");
     testing.expectError(error.ItBroke, another.wait());
 }
-
-async fn sleepALittle(count: *usize) void {
+fn sleepALittle(count: *usize) callconv(.Async) void {
     std.time.sleep(1 * std.time.millisecond);
     _ = @atomicRmw(usize, count, .Add, 1, .SeqCst);
 }
-
-async fn increaseByTen(count: *usize) void {
+fn increaseByTen(count: *usize) callconv(.Async) void {
     var i: usize = 0;
     while (i < 10) : (i += 1) {
         _ = @atomicRmw(usize, count, .Add, 1, .SeqCst);
     }
 }
-
-async fn doSomethingThatFails() anyerror!void {}
-async fn somethingElse() anyerror!void {
+fn doSomethingThatFails() callconv(.Async) anyerror!void {}
+fn somethingElse() callconv(.Async) anyerror!void {
     return error.ItBroke;
 }
diff --git a/lib/std/event/lock.zig b/lib/std/event/lock.zig
index ff1f738c5e..179b881c9c 100644
--- a/lib/std/event/lock.zig
+++ b/lib/std/event/lock.zig
@@ -89,7 +89,7 @@ pub const Lock = struct {
         while (self.queue.get()) |node| resume node.data;
     }
 
-    pub async fn acquire(self: *Lock) Held {
+    pub fn acquire(self: *Lock) callconv(.Async) Held {
         var my_tick_node = Loop.NextTickNode.init(@frame());
 
         errdefer _ = self.queue.remove(&my_tick_node); // TODO test canceling an acquire
@@ -134,8 +134,7 @@ test "std.event.Lock" {
     const expected_result = [1]i32{3 * @intCast(i32, shared_test_data.len)} ** shared_test_data.len;
     testing.expectEqualSlices(i32, &expected_result, &shared_test_data);
 }
-
-async fn testLock(lock: *Lock) void {
+fn testLock(lock: *Lock) callconv(.Async) void {
     var handle1 = async lockRunner(lock);
     var tick_node1 = Loop.NextTickNode{
         .prev = undefined,
@@ -167,8 +166,7 @@ async fn testLock(lock: *Lock) void {
 
 var shared_test_data = [1]i32{0} ** 10;
 var shared_test_index: usize = 0;
-
-async fn lockRunner(lock: *Lock) void {
+fn lockRunner(lock: *Lock) callconv(.Async) void {
     suspend; // resumed by onNextTick
 
     var i: usize = 0;
diff --git a/lib/std/event/locked.zig b/lib/std/event/locked.zig
index 5e9c0ea10e..e921803447 100644
--- a/lib/std/event/locked.zig
+++ b/lib/std/event/locked.zig
@@ -31,7 +31,7 @@ pub fn Locked(comptime T: type) type {
             self.lock.deinit();
         }
 
-        pub async fn acquire(self: *Self) HeldLock {
+        pub fn acquire(self: *Self) callconv(.Async) HeldLock {
             return HeldLock{
                 // TODO guaranteed allocation elision
                 .held = self.lock.acquire(),
diff --git a/lib/std/event/loop.zig b/lib/std/event/loop.zig
index 6fa65f90dd..607e2f24ca 100644
--- a/lib/std/event/loop.zig
+++ b/lib/std/event/loop.zig
@@ -195,7 +195,7 @@ pub const Loop = struct {
     const wakeup_bytes = [_]u8{0x1} ** 8;
 
     fn initOsData(self: *Loop, extra_thread_count: usize) InitOsDataError!void {
-        noasync switch (builtin.os.tag) {
+        nosuspend switch (builtin.os.tag) {
             .linux => {
                 errdefer {
                     while (self.available_eventfd_resume_nodes.pop()) |node| os.close(node.data.eventfd);
@@ -371,7 +371,7 @@ pub const Loop = struct {
     }
 
     fn deinitOsData(self: *Loop) void {
-        noasync switch (builtin.os.tag) {
+        nosuspend switch (builtin.os.tag) {
             .linux => {
                 os.close(self.os_data.final_eventfd);
                 while (self.available_eventfd_resume_nodes.pop()) |node| os.close(node.data.eventfd);
@@ -493,7 +493,7 @@ pub const Loop = struct {
     pub fn waitUntilFdWritableOrReadable(self: *Loop, fd: os.fd_t) void {
         switch (builtin.os.tag) {
             .linux => {
-                self.linuxWaitFd(@intCast(usize, fd), os.EPOLLET | os.EPOLLONESHOT | os.EPOLLOUT | os.EPOLLIN);
+                self.linuxWaitFd(fd, os.EPOLLET | os.EPOLLONESHOT | os.EPOLLOUT | os.EPOLLIN);
             },
             .macosx, .freebsd, .netbsd, .dragonfly => {
                 self.bsdWaitKev(@intCast(usize, fd), os.EVFILT_READ, os.EV_ONESHOT);
@@ -503,7 +503,7 @@ pub const Loop = struct {
         }
     }
 
-    pub async fn bsdWaitKev(self: *Loop, ident: usize, filter: i16, fflags: u32) void {
+    pub fn bsdWaitKev(self: *Loop, ident: usize, filter: i16, flags: u16) void {
         var resume_node = ResumeNode.Basic{
             .base = ResumeNode{
                 .id = ResumeNode.Id.Basic,
@@ -512,21 +512,28 @@ pub const Loop = struct {
             },
             .kev = undefined,
         };
-        defer self.bsdRemoveKev(ident, filter);
+
+        defer {
+            // If the kevent was set to be ONESHOT, it doesn't need to be deleted manually.
+            if (flags & os.EV_ONESHOT != 0) {
+                self.bsdRemoveKev(ident, filter);
+            }
+        }
+
         suspend {
-            self.bsdAddKev(&resume_node, ident, filter, fflags) catch unreachable;
+            self.bsdAddKev(&resume_node, ident, filter, flags) catch unreachable;
         }
     }
 
     /// resume_node must live longer than the anyframe that it holds a reference to.
-    pub fn bsdAddKev(self: *Loop, resume_node: *ResumeNode.Basic, ident: usize, filter: i16, fflags: u32) !void {
+    pub fn bsdAddKev(self: *Loop, resume_node: *ResumeNode.Basic, ident: usize, filter: i16, flags: u16) !void {
         self.beginOneEvent();
         errdefer self.finishOneEvent();
         var kev = [1]os.Kevent{os.Kevent{
             .ident = ident,
             .filter = filter,
-            .flags = os.EV_ADD | os.EV_ENABLE | os.EV_CLEAR,
-            .fflags = fflags,
+            .flags = os.EV_ADD | os.EV_ENABLE | os.EV_CLEAR | flags,
+            .fflags = 0,
             .data = 0,
             .udata = @ptrToInt(&resume_node.base),
         }};
@@ -616,14 +623,16 @@ pub const Loop = struct {
 
         self.workerRun();
 
-        switch (builtin.os.tag) {
-            .linux,
-            .macosx,
-            .freebsd,
-            .netbsd,
-            .dragonfly,
-            => self.fs_thread.wait(),
-            else => {},
+        if (!builtin.single_threaded) {
+            switch (builtin.os.tag) {
+                .linux,
+                .macosx,
+                .freebsd,
+                .netbsd,
+                .dragonfly,
+                => self.fs_thread.wait(),
+                else => {},
+            }
         }
 
         for (self.extra_threads) |extra_thread| {
@@ -663,7 +672,7 @@ pub const Loop = struct {
     }
 
     pub fn finishOneEvent(self: *Loop) void {
-        noasync {
+        nosuspend {
             const prev = @atomicRmw(usize, &self.pending_event_count, .Sub, 1, .SeqCst);
             if (prev != 1) return;
 
@@ -1041,7 +1050,7 @@ pub const Loop = struct {
     }
 
     fn posixFsRun(self: *Loop) void {
-        noasync while (true) {
+        nosuspend while (true) {
             self.fs_thread_wakeup.reset();
             while (self.fs_queue.get()) |node| {
                 switch (node.data.msg) {
diff --git a/lib/std/event/rwlock.zig b/lib/std/event/rwlock.zig
index 425088063f..7a47c27dd8 100644
--- a/lib/std/event/rwlock.zig
+++ b/lib/std/event/rwlock.zig
@@ -97,7 +97,7 @@ pub const RwLock = struct {
         while (self.reader_queue.get()) |node| resume node.data;
     }
 
-    pub async fn acquireRead(self: *RwLock) HeldRead {
+    pub fn acquireRead(self: *RwLock) callconv(.Async) HeldRead {
         _ = @atomicRmw(usize, &self.reader_lock_count, .Add, 1, .SeqCst);
 
         suspend {
@@ -130,7 +130,7 @@ pub const RwLock = struct {
         return HeldRead{ .lock = self };
     }
 
-    pub async fn acquireWrite(self: *RwLock) HeldWrite {
+    pub fn acquireWrite(self: *RwLock) callconv(.Async) HeldWrite {
         suspend {
             var my_tick_node = Loop.NextTickNode{
                 .data = @frame(),
@@ -225,8 +225,7 @@ test "std.event.RwLock" {
     const expected_result = [1]i32{shared_it_count * @intCast(i32, shared_test_data.len)} ** shared_test_data.len;
     testing.expectEqualSlices(i32, expected_result, shared_test_data);
 }
-
-async fn testLock(allocator: *Allocator, lock: *RwLock) void {
+fn testLock(allocator: *Allocator, lock: *RwLock) callconv(.Async) void {
     var read_nodes: [100]Loop.NextTickNode = undefined;
     for (read_nodes) |*read_node| {
         const frame = allocator.create(@Frame(readRunner)) catch @panic("memory");
@@ -259,8 +258,7 @@ const shared_it_count = 10;
 var shared_test_data = [1]i32{0} ** 10;
 var shared_test_index: usize = 0;
 var shared_count: usize = 0;
-
-async fn writeRunner(lock: *RwLock) void {
+fn writeRunner(lock: *RwLock) callconv(.Async) void {
     suspend; // resumed by onNextTick
 
     var i: usize = 0;
@@ -277,8 +275,7 @@ async fn writeRunner(lock: *RwLock) void {
         shared_test_index = 0;
     }
 }
-
-async fn readRunner(lock: *RwLock) void {
+fn readRunner(lock: *RwLock) callconv(.Async) void {
     suspend; // resumed by onNextTick
     std.time.sleep(1);
 
diff --git a/lib/std/event/rwlocked.zig b/lib/std/event/rwlocked.zig
index 3f4c6ddbf8..9a569e8f1f 100644
--- a/lib/std/event/rwlocked.zig
+++ b/lib/std/event/rwlocked.zig
@@ -40,14 +40,14 @@ pub fn RwLocked(comptime T: type) type {
             self.lock.deinit();
         }
 
-        pub async fn acquireRead(self: *Self) HeldReadLock {
+        pub fn acquireRead(self: *Self) callconv(.Async) HeldReadLock {
             return HeldReadLock{
                 .held = self.lock.acquireRead(),
                 .value = &self.locked_data,
             };
         }
 
-        pub async fn acquireWrite(self: *Self) HeldWriteLock {
+        pub fn acquireWrite(self: *Self) callconv(.Async) HeldWriteLock {
             return HeldWriteLock{
                 .held = self.lock.acquireWrite(),
                 .value = &self.locked_data,
diff --git a/lib/std/fs/file.zig b/lib/std/fs/file.zig
index 9d72733395..3ea147679d 100644
--- a/lib/std/fs/file.zig
+++ b/lib/std/fs/file.zig
@@ -66,7 +66,7 @@ pub const File = struct {
         lock_nonblocking: bool = false,
 
         /// Setting this to `.blocking` prevents `O_NONBLOCK` from being passed even
-        /// if `std.io.is_async`. It allows the use of `noasync` when calling functions
+        /// if `std.io.is_async`. It allows the use of `nosuspend` when calling functions
         /// related to opening the file, reading, writing, and locking.
         intended_io_mode: io.ModeOverride = io.default_mode,
     };
@@ -112,7 +112,7 @@ pub const File = struct {
         mode: Mode = default_mode,
 
         /// Setting this to `.blocking` prevents `O_NONBLOCK` from being passed even
-        /// if `std.io.is_async`. It allows the use of `noasync` when calling functions
+        /// if `std.io.is_async`. It allows the use of `nosuspend` when calling functions
         /// related to opening the file, reading, writing, and locking.
         intended_io_mode: io.ModeOverride = io.default_mode,
     };
diff --git a/lib/std/hash/auto_hash.zig b/lib/std/hash/auto_hash.zig
index 70c858098d..a33b23354b 100644
--- a/lib/std/hash/auto_hash.zig
+++ b/lib/std/hash/auto_hash.zig
@@ -113,11 +113,9 @@ pub fn hash(hasher: var, key: var, comptime strat: HashStrategy) void {
                 hasher.update(mem.asBytes(&key));
             } else {
                 // Otherwise, hash every element.
-                // TODO remove the copy to an array once field access is done.
-                const array: [info.len]info.child = key;
                 comptime var i = 0;
                 inline while (i < info.len) : (i += 1) {
-                    hash(hasher, array[i], strat);
+                    hash(hasher, key[i], strat);
                 }
             }
         },
diff --git a/lib/std/json.zig b/lib/std/json.zig
index b2b2db6493..fc205d2279 100644
--- a/lib/std/json.zig
+++ b/lib/std/json.zig
@@ -136,7 +136,7 @@ pub const Token = union(enum) {
 /// they are encountered. No copies or allocations are performed during parsing and the entire
 /// parsing state requires ~40-50 bytes of stack space.
 ///
-/// Conforms strictly to RFC8529.
+/// Conforms strictly to RFC8259.
 ///
 /// For a non-byte based wrapper, consider using TokenStream instead.
 pub const StreamingParser = struct {
@@ -2194,7 +2194,7 @@ test "write json then parse it" {
     try jw.emitBool(true);
 
     try jw.objectField("int");
-    try jw.emitNumber(@as(i32, 1234));
+    try jw.emitNumber(1234);
 
     try jw.objectField("array");
     try jw.beginArray();
@@ -2203,7 +2203,7 @@ test "write json then parse it" {
     try jw.emitNull();
 
     try jw.arrayElem();
-    try jw.emitNumber(@as(f64, 12.34));
+    try jw.emitNumber(12.34);
 
     try jw.endArray();
 
@@ -2336,7 +2336,7 @@ pub const StringifyOptions = struct {
         /// After a colon, should whitespace be inserted?
         separator: bool = true,
 
-        fn outputIndent(
+        pub fn outputIndent(
             whitespace: @This(),
             out_stream: var,
         ) @TypeOf(out_stream).Error!void {
diff --git a/lib/std/json/write_stream.zig b/lib/std/json/write_stream.zig
index 60974a207e..6dd02a03cf 100644
--- a/lib/std/json/write_stream.zig
+++ b/lib/std/json/write_stream.zig
@@ -168,8 +168,11 @@ pub fn WriteStream(comptime OutStream: type, comptime max_depth: usize) type {
                         return;
                     }
                 },
-                .Float => if (@floatCast(f64, value) == value) {
-                    try self.stream.print("{}", .{value});
+                .ComptimeInt => {
+                    return self.emitNumber(@as(std.math.IntFittingRange(value, value), value));
+                },
+                .Float, .ComptimeFloat => if (@floatCast(f64, value) == value) {
+                    try self.stream.print("{}", .{@floatCast(f64, value)});
                     self.popState();
                     return;
                 },
@@ -180,6 +183,7 @@ pub fn WriteStream(comptime OutStream: type, comptime max_depth: usize) type {
         }
 
         pub fn emitString(self: *Self, string: []const u8) !void {
+            assert(self.state[self.state_index] == State.Value);
             try self.writeEscapedString(string);
             self.popState();
         }
@@ -191,7 +195,9 @@ pub fn WriteStream(comptime OutStream: type, comptime max_depth: usize) type {
 
         /// Writes the complete json into the output stream
         pub fn emitJson(self: *Self, json: std.json.Value) Stream.Error!void {
+            assert(self.state[self.state_index] == State.Value);
             try self.stringify(json);
+            self.popState();
         }
 
         fn indent(self: *Self) !void {
@@ -233,7 +239,32 @@ test "json write stream" {
     defer arena_allocator.deinit();
 
     var w = std.json.writeStream(out, 10);
-    try w.emitJson(try getJson(&arena_allocator.allocator));
+
+    try w.beginObject();
+    
+    try w.objectField("object");
+    try w.emitJson(try getJsonObject(&arena_allocator.allocator));
+
+    try w.objectField("string");
+    try w.emitString("This is a string");
+
+    try w.objectField("array");
+    try w.beginArray();
+    try w.arrayElem();
+    try w.emitString("Another string");
+    try w.arrayElem();
+    try w.emitNumber(@as(i32, 1));
+    try w.arrayElem();
+    try w.emitNumber(@as(f32, 3.5));
+    try w.endArray();
+
+    try w.objectField("int");
+    try w.emitNumber(@as(i32, 10));
+
+    try w.objectField("float");
+    try w.emitNumber(@as(f32, 3.5));
+
+    try w.endObject();
 
     const result = slice_stream.getWritten();
     const expected =
@@ -246,38 +277,18 @@ test "json write stream" {
         \\ "array": [
         \\  "Another string",
         \\  1,
-        \\  3.14e+00
+        \\  3.5e+00
         \\ ],
         \\ "int": 10,
-        \\ "float": 3.14e+00
+        \\ "float": 3.5e+00
         \\}
     ;
     std.testing.expect(std.mem.eql(u8, expected, result));
 }
 
-fn getJson(allocator: *std.mem.Allocator) !std.json.Value {
-    var value = std.json.Value{ .Object = std.json.ObjectMap.init(allocator) };
-    _ = try value.Object.put("string", std.json.Value{ .String = "This is a string" });
-    _ = try value.Object.put("int", std.json.Value{ .Integer = @intCast(i64, 10) });
-    _ = try value.Object.put("float", std.json.Value{ .Float = 3.14 });
-    _ = try value.Object.put("array", try getJsonArray(allocator));
-    _ = try value.Object.put("object", try getJsonObject(allocator));
-    return value;
-}
-
 fn getJsonObject(allocator: *std.mem.Allocator) !std.json.Value {
     var value = std.json.Value{ .Object = std.json.ObjectMap.init(allocator) };
     _ = try value.Object.put("one", std.json.Value{ .Integer = @intCast(i64, 1) });
     _ = try value.Object.put("two", std.json.Value{ .Float = 2.0 });
     return value;
 }
-
-fn getJsonArray(allocator: *std.mem.Allocator) !std.json.Value {
-    var value = std.json.Value{ .Array = std.json.Array.init(allocator) };
-    var array = &value.Array;
-    _ = try array.append(std.json.Value{ .String = "Another string" });
-    _ = try array.append(std.json.Value{ .Integer = @intCast(i64, 1) });
-    _ = try array.append(std.json.Value{ .Float = 3.14 });
-
-    return value;
-}
diff --git a/lib/std/mem.zig b/lib/std/mem.zig
index 95d6b77e87..cfd3fd38d8 100644
--- a/lib/std/mem.zig
+++ b/lib/std/mem.zig
@@ -124,9 +124,9 @@ pub const Allocator = struct {
 
     fn AllocWithOptionsPayload(comptime Elem: type, comptime alignment: ?u29, comptime sentinel: ?Elem) type {
         if (sentinel) |s| {
-            return [:s]align(alignment orelse @alignOf(T)) Elem;
+            return [:s]align(alignment orelse @alignOf(Elem)) Elem;
         } else {
-            return []align(alignment orelse @alignOf(T)) Elem;
+            return []align(alignment orelse @alignOf(Elem)) Elem;
         }
     }
 
@@ -296,6 +296,22 @@ pub const Allocator = struct {
     }
 };
 
+var failAllocator = Allocator {
+    .reallocFn = failAllocatorRealloc,
+    .shrinkFn = failAllocatorShrink,
+};
+fn failAllocatorRealloc(self: *Allocator, old_mem: []u8, old_align: u29, new_size: usize, new_align: u29) ![]u8 {
+    return error.OutOfMemory;
+}
+fn failAllocatorShrink(self: *Allocator, old_mem: []u8, old_align: u29, new_size: usize, new_align: u29) []u8 {
+    @panic("failAllocatorShrink should never be called because it cannot allocate");
+}
+
+test "mem.Allocator basics" {
+    testing.expectError(error.OutOfMemory, failAllocator.alloc(u8, 1));
+    testing.expectError(error.OutOfMemory, failAllocator.allocSentinel(u8, 1, 0));
+}
+
 /// Copy all of source into dest at position 0.
 /// dest.len must be >= source.len.
 /// dest.ptr must be <= src.ptr.
@@ -381,6 +397,9 @@ pub fn zeroes(comptime T: type) T {
             }
         },
         .Array => |info| {
+            if (info.sentinel) |sentinel| {
+                return [_:sentinel]info.child{zeroes(info.child)} ** info.len;
+            }
             return [_]info.child{zeroes(info.child)} ** info.len;
         },
         .Vector,
@@ -441,6 +460,7 @@ test "mem.zeroes" {
         array: [2]u32,
         optional_int: ?u8,
         empty: void,
+        sentinel: [3:0]u8,
     };
 
     const b = zeroes(ZigStruct);
@@ -465,6 +485,9 @@ test "mem.zeroes" {
         testing.expectEqual(@as(u32, 0), e);
     }
     testing.expectEqual(@as(?u8, null), b.optional_int);
+    for (b.sentinel) |e| {
+        testing.expectEqual(@as(u8, 0), e);
+    }
 }
 
 pub fn secureZero(comptime T: type, s: []T) void {
diff --git a/lib/std/net.zig b/lib/std/net.zig
index b9681bc618..96c95fc497 100644
--- a/lib/std/net.zig
+++ b/lib/std/net.zig
@@ -341,7 +341,7 @@ pub const Address = extern union {
         return mem.eql(u8, a_bytes, b_bytes);
     }
 
-    fn getOsSockLen(self: Address) os.socklen_t {
+    pub fn getOsSockLen(self: Address) os.socklen_t {
         switch (self.any.family) {
             os.AF_INET => return @sizeOf(os.sockaddr_in),
             os.AF_INET6 => return @sizeOf(os.sockaddr_in6),
@@ -377,7 +377,6 @@ pub fn connectUnixSocket(path: []const u8) !fs.File {
 
     return fs.File{
         .handle = sockfd,
-        .io_mode = std.io.mode,
     };
 }
 
@@ -386,7 +385,7 @@ pub const AddressList = struct {
     addrs: []Address,
     canon_name: ?[]u8,
 
-    fn deinit(self: *AddressList) void {
+    pub fn deinit(self: *AddressList) void {
         // Here we copy the arena allocator into stack memory, because
         // otherwise it would destroy itself while it was still working.
         var arena = self.arena;
@@ -1366,6 +1365,10 @@ pub const StreamServer = struct {
 
         /// Firewall rules forbid connection.
         BlockedByFirewall,
+
+        /// Permission to create a socket of the specified type and/or
+        /// protocol is denied.
+        PermissionDenied,
     } || os.UnexpectedError;
 
     pub const Connection = struct {
diff --git a/lib/std/net/test.zig b/lib/std/net/test.zig
index 087f965c4e..f4f97d3944 100644
--- a/lib/std/net/test.zig
+++ b/lib/std/net/test.zig
@@ -81,7 +81,7 @@ test "resolve DNS" {
 test "listen on a port, send bytes, receive bytes" {
     if (!std.io.is_async) return error.SkipZigTest;
 
-    if (std.builtin.os.tag != .linux) {
+    if (std.builtin.os.tag != .linux and !std.builtin.os.tag.isDarwin()) {
         // TODO build abstractions for other operating systems
         return error.SkipZigTest;
     }
diff --git a/lib/std/os.zig b/lib/std/os.zig
index ff7089ceb0..1eab9affe7 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -292,6 +292,7 @@ pub const ReadError = error{
     OperationAborted,
     BrokenPipe,
     ConnectionResetByPeer,
+    ConnectionTimedOut,
 
     /// This error occurs when no global event loop is configured,
     /// and reading from the file descriptor would block.
@@ -351,6 +352,7 @@ pub fn read(fd: fd_t, buf: []u8) ReadError!usize {
             ENOBUFS => return error.SystemResources,
             ENOMEM => return error.SystemResources,
             ECONNRESET => return error.ConnectionResetByPeer,
+            ETIMEDOUT => return error.ConnectionTimedOut,
             else => |err| return unexpectedErrno(err),
         }
     }
@@ -2156,6 +2158,9 @@ pub const SocketError = error{
 
     /// The protocol type or the specified protocol is not supported within this domain.
     ProtocolNotSupported,
+
+    /// The socket type is not supported by the protocol.
+    SocketTypeNotSupported,
 } || UnexpectedError;
 
 pub fn socket(domain: u32, socket_type: u32, protocol: u32) SocketError!fd_t {
@@ -2164,11 +2169,11 @@ pub fn socket(domain: u32, socket_type: u32, protocol: u32) SocketError!fd_t {
         socket_type & ~@as(u32, SOCK_NONBLOCK | SOCK_CLOEXEC)
     else
         socket_type;
-    const rc = system.socket(domain, socket_type, protocol);
+    const rc = system.socket(domain, filtered_sock_type, protocol);
     switch (errno(rc)) {
         0 => {
             const fd = @intCast(fd_t, rc);
-            if (!have_sock_flags and filtered_sock_type != socket_type) {
+            if (!have_sock_flags) {
                 try setSockFlags(fd, socket_type);
             }
             return fd;
@@ -2181,6 +2186,7 @@ pub fn socket(domain: u32, socket_type: u32, protocol: u32) SocketError!fd_t {
         ENOBUFS => return error.SystemResources,
         ENOMEM => return error.SystemResources,
         EPROTONOSUPPORT => return error.ProtocolNotSupported,
+        EPROTOTYPE => return error.SocketTypeNotSupported,
         else => |err| return unexpectedErrno(err),
     }
 }
@@ -2290,6 +2296,10 @@ pub const AcceptError = error{
     /// This error occurs when no global event loop is configured,
     /// and accepting from the socket would block.
     WouldBlock,
+
+    /// Permission to create a socket of the specified type and/or
+    /// protocol is denied.
+    PermissionDenied,
 } || UnexpectedError;
 
 /// Accept a connection on a socket.
@@ -2331,7 +2341,7 @@ pub fn accept(
         switch (errno(rc)) {
             0 => {
                 const fd = @intCast(fd_t, rc);
-                if (!have_accept4 and flags != 0) {
+                if (!have_accept4) {
                     try setSockFlags(fd, flags);
                 }
                 return fd;
@@ -2539,7 +2549,7 @@ pub fn connect(sockfd: fd_t, sock_addr: *const sockaddr, len: socklen_t) Connect
             EAFNOSUPPORT => return error.AddressFamilyNotSupported,
             EAGAIN, EINPROGRESS => {
                 const loop = std.event.Loop.instance orelse return error.WouldBlock;
-                loop.waitUntilFdWritableOrReadable(sockfd);
+                loop.waitUntilFdWritable(sockfd);
                 return getsockoptError(sockfd);
             },
             EALREADY => unreachable, // The socket is nonblocking and a previous connection attempt has not yet been completed.
@@ -3267,26 +3277,26 @@ pub fn fcntl(fd: fd_t, cmd: i32, arg: usize) FcntlError!usize {
 }
 
 fn setSockFlags(fd: fd_t, flags: u32) !void {
-    {
+    if ((flags & SOCK_CLOEXEC) != 0) {
         var fd_flags = fcntl(fd, F_GETFD, 0) catch |err| switch (err) {
             error.FileBusy => unreachable,
             error.Locked => unreachable,
             else => |e| return e,
         };
-        if ((flags & SOCK_NONBLOCK) != 0) fd_flags |= FD_CLOEXEC;
+        fd_flags |= FD_CLOEXEC;
         _ = fcntl(fd, F_SETFD, fd_flags) catch |err| switch (err) {
             error.FileBusy => unreachable,
             error.Locked => unreachable,
             else => |e| return e,
         };
     }
-    {
+    if ((flags & SOCK_NONBLOCK) != 0) {
         var fl_flags = fcntl(fd, F_GETFL, 0) catch |err| switch (err) {
             error.FileBusy => unreachable,
             error.Locked => unreachable,
             else => |e| return e,
         };
-        if ((flags & SOCK_CLOEXEC) != 0) fl_flags |= O_NONBLOCK;
+        fl_flags |= O_NONBLOCK;
         _ = fcntl(fd, F_SETFL, fl_flags) catch |err| switch (err) {
             error.FileBusy => unreachable,
             error.Locked => unreachable,
diff --git a/lib/std/os/bits/darwin.zig b/lib/std/os/bits/darwin.zig
index d116d6157a..8e4682b3f4 100644
--- a/lib/std/os/bits/darwin.zig
+++ b/lib/std/os/bits/darwin.zig
@@ -125,7 +125,7 @@ pub const empty_sigset = sigset_t(0);
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with function name.
 pub const Sigaction = extern struct {
-    handler: extern fn (c_int) void,
+    handler: fn (c_int) callconv(.C) void,
     sa_mask: sigset_t,
     sa_flags: c_int,
 };
@@ -1263,10 +1263,10 @@ pub const RTLD_NOLOAD = 0x10;
 pub const RTLD_NODELETE = 0x80;
 pub const RTLD_FIRST = 0x100;
 
-pub const RTLD_NEXT = @intToPtr(*c_void, ~maxInt(usize));
-pub const RTLD_DEFAULT = @intToPtr(*c_void, ~maxInt(usize) - 1);
-pub const RTLD_SELF = @intToPtr(*c_void, ~maxInt(usize) - 2);
-pub const RTLD_MAIN_ONLY = @intToPtr(*c_void, ~maxInt(usize) - 4);
+pub const RTLD_NEXT = @intToPtr(*c_void, @bitCast(usize, @as(isize, -1)));
+pub const RTLD_DEFAULT = @intToPtr(*c_void, @bitCast(usize, @as(isize, -2)));
+pub const RTLD_SELF = @intToPtr(*c_void, @bitCast(usize, @as(isize, -3)));
+pub const RTLD_MAIN_ONLY = @intToPtr(*c_void, @bitCast(usize, @as(isize, -5)));
 
 /// duplicate file descriptor
 pub const F_DUPFD = 0;
diff --git a/lib/std/os/bits/dragonfly.zig b/lib/std/os/bits/dragonfly.zig
index 6a6c871fc5..df22678323 100644
--- a/lib/std/os/bits/dragonfly.zig
+++ b/lib/std/os/bits/dragonfly.zig
@@ -458,9 +458,9 @@ pub const S_IFSOCK = 49152;
 pub const S_IFWHT = 57344;
 pub const S_IFMT = 61440;
 
-pub const SIG_ERR = @intToPtr(extern fn (i32) void, maxInt(usize));
-pub const SIG_DFL = @intToPtr(extern fn (i32) void, 0);
-pub const SIG_IGN = @intToPtr(extern fn (i32) void, 1);
+pub const SIG_ERR = @intToPtr(fn (i32) callconv(.C) void, maxInt(usize));
+pub const SIG_DFL = @intToPtr(fn (i32) callconv(.C) void, 0);
+pub const SIG_IGN = @intToPtr(fn (i32) callconv(.C) void, 1);
 pub const BADSIG = SIG_ERR;
 pub const SIG_BLOCK = 1;
 pub const SIG_UNBLOCK = 2;
@@ -519,13 +519,13 @@ pub const sigset_t = extern struct {
 pub const sig_atomic_t = c_int;
 pub const Sigaction = extern struct {
     __sigaction_u: extern union {
-        __sa_handler: ?extern fn (c_int) void,
-        __sa_sigaction: ?extern fn (c_int, [*c]siginfo_t, ?*c_void) void,
+        __sa_handler: ?fn (c_int) callconv(.C) void,
+        __sa_sigaction: ?fn (c_int, [*c]siginfo_t, ?*c_void) callconv(.C) void,
     },
     sa_flags: c_int,
     sa_mask: sigset_t,
 };
-pub const sig_t = [*c]extern fn (c_int) void;
+pub const sig_t = [*c]fn (c_int) callconv(.C) void;
 
 pub const sigvec = extern struct {
     sv_handler: [*c]__sighandler_t,
diff --git a/lib/std/os/bits/freebsd.zig b/lib/std/os/bits/freebsd.zig
index 9999dca62f..eee7504366 100644
--- a/lib/std/os/bits/freebsd.zig
+++ b/lib/std/os/bits/freebsd.zig
@@ -725,16 +725,16 @@ pub const winsize = extern struct {
 
 const NSIG = 32;
 
-pub const SIG_ERR = @intToPtr(extern fn (i32) void, maxInt(usize));
-pub const SIG_DFL = @intToPtr(extern fn (i32) void, 0);
-pub const SIG_IGN = @intToPtr(extern fn (i32) void, 1);
+pub const SIG_ERR = @intToPtr(fn (i32) callconv(.C) void, maxInt(usize));
+pub const SIG_DFL = @intToPtr(fn (i32) callconv(.C) void, 0);
+pub const SIG_IGN = @intToPtr(fn (i32) callconv(.C) void, 1);
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
     /// signal handler
     __sigaction_u: extern union {
-        __sa_handler: extern fn (i32) void,
-        __sa_sigaction: extern fn (i32, *__siginfo, usize) void,
+        __sa_handler: fn (i32) callconv(.C) void,
+        __sa_sigaction: fn (i32, *__siginfo, usize) callconv(.C) void,
     },
 
     /// see signal options
diff --git a/lib/std/os/bits/linux.zig b/lib/std/os/bits/linux.zig
index 750b487754..438be2299b 100644
--- a/lib/std/os/bits/linux.zig
+++ b/lib/std/os/bits/linux.zig
@@ -813,15 +813,15 @@ pub const app_mask: sigset_t = [2]u32{ 0xfffffffc, 0x7fffffff } ++ [_]u32{0xffff
 pub const k_sigaction = if (is_mips)
     extern struct {
         flags: usize,
-        sigaction: ?extern fn (i32, *siginfo_t, ?*c_void) void,
+        sigaction: ?fn (i32, *siginfo_t, ?*c_void) callconv(.C) void,
         mask: [4]u32,
-        restorer: extern fn () void,
+        restorer: fn () callconv(.C) void,
     }
 else
     extern struct {
-        sigaction: ?extern fn (i32, *siginfo_t, ?*c_void) void,
+        sigaction: ?fn (i32, *siginfo_t, ?*c_void) callconv(.C) void,
         flags: usize,
-        restorer: extern fn () void,
+        restorer: fn () callconv(.C) void,
         mask: [2]u32,
     };
 
@@ -831,7 +831,7 @@ pub const Sigaction = extern struct {
     sigaction: ?sigaction_fn,
     mask: sigset_t,
     flags: u32,
-    restorer: ?extern fn () void = null,
+    restorer: ?fn () callconv(.C) void = null,
 };
 
 pub const SIG_ERR = @intToPtr(?Sigaction.sigaction_fn, maxInt(usize));
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 15f9bf9b62..6653293e59 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -599,7 +599,7 @@ pub fn flock(fd: fd_t, operation: i32) usize {
 var vdso_clock_gettime = @ptrCast(?*const c_void, init_vdso_clock_gettime);
 
 // We must follow the C calling convention when we call into the VDSO
-const vdso_clock_gettime_ty = extern fn (i32, *timespec) usize;
+const vdso_clock_gettime_ty = fn (i32, *timespec) callconv(.C) usize;
 
 pub fn clock_gettime(clk_id: i32, tp: *timespec) usize {
     if (@hasDecl(@This(), "VDSO_CGT_SYM")) {
@@ -791,7 +791,7 @@ pub fn sigaction(sig: u6, noalias act: *const Sigaction, noalias oact: ?*Sigacti
         .sigaction = act.sigaction,
         .flags = act.flags | SA_RESTORER,
         .mask = undefined,
-        .restorer = @ptrCast(extern fn () void, restorer_fn),
+        .restorer = @ptrCast(fn () callconv(.C) void, restorer_fn),
     };
     var ksa_old: k_sigaction = undefined;
     const ksa_mask_size = @sizeOf(@TypeOf(ksa_old.mask));
diff --git a/lib/std/os/linux/arm-eabi.zig b/lib/std/os/linux/arm-eabi.zig
index c052aeab4e..352afeeb04 100644
--- a/lib/std/os/linux/arm-eabi.zig
+++ b/lib/std/os/linux/arm-eabi.zig
@@ -86,7 +86,7 @@ pub fn syscall6(
 }
 
 /// This matches the libc clone function.
-pub extern fn clone(func: extern fn (arg: usize) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
+pub extern fn clone(func: fn (arg: usize) callconv(.C) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
 
 pub fn restore() callconv(.Naked) void {
     return asm volatile ("svc #0"
diff --git a/lib/std/os/linux/arm64.zig b/lib/std/os/linux/arm64.zig
index 52ab3656e0..49548522ec 100644
--- a/lib/std/os/linux/arm64.zig
+++ b/lib/std/os/linux/arm64.zig
@@ -86,7 +86,7 @@ pub fn syscall6(
 }
 
 /// This matches the libc clone function.
-pub extern fn clone(func: extern fn (arg: usize) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
+pub extern fn clone(func: fn (arg: usize) callconv(.C) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
 
 pub const restore = restore_rt;
 
diff --git a/lib/std/os/linux/i386.zig b/lib/std/os/linux/i386.zig
index 0342f0754e..a4fdf8a346 100644
--- a/lib/std/os/linux/i386.zig
+++ b/lib/std/os/linux/i386.zig
@@ -106,7 +106,7 @@ pub fn socketcall(call: usize, args: [*]usize) usize {
 }
 
 /// This matches the libc clone function.
-pub extern fn clone(func: extern fn (arg: usize) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
+pub extern fn clone(func: fn (arg: usize) callconv(.C) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
 
 pub fn restore() callconv(.Naked) void {
     return asm volatile ("int $0x80"
diff --git a/lib/std/os/linux/mips.zig b/lib/std/os/linux/mips.zig
index 87c55db9f6..5b5c1e1f34 100644
--- a/lib/std/os/linux/mips.zig
+++ b/lib/std/os/linux/mips.zig
@@ -142,7 +142,7 @@ pub fn syscall6(
 }
 
 /// This matches the libc clone function.
-pub extern fn clone(func: extern fn (arg: usize) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
+pub extern fn clone(func: fn (arg: usize) callconv(.C) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
 
 pub fn restore() callconv(.Naked) void {
     return asm volatile ("syscall"
diff --git a/lib/std/os/linux/riscv64.zig b/lib/std/os/linux/riscv64.zig
index 3832bfbcca..39cc13f5b6 100644
--- a/lib/std/os/linux/riscv64.zig
+++ b/lib/std/os/linux/riscv64.zig
@@ -85,7 +85,7 @@ pub fn syscall6(
     );
 }
 
-pub extern fn clone(func: extern fn (arg: usize) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
+pub extern fn clone(func: fn (arg: usize) callconv(.C) u8, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
 
 pub const restore = restore_rt;
 
diff --git a/lib/std/os/linux/x86_64.zig b/lib/std/os/linux/x86_64.zig
index b60dcd80e9..33d2b66670 100644
--- a/lib/std/os/linux/x86_64.zig
+++ b/lib/std/os/linux/x86_64.zig
@@ -86,7 +86,7 @@ pub fn syscall6(
 }
 
 /// This matches the libc clone function.
-pub extern fn clone(func: extern fn (arg: usize) u8, stack: usize, flags: usize, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
+pub extern fn clone(func: fn (arg: usize) callconv(.C) u8, stack: usize, flags: usize, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
 
 pub const restore = restore_rt;
 
diff --git a/lib/std/os/uefi/protocols/absolute_pointer_protocol.zig b/lib/std/os/uefi/protocols/absolute_pointer_protocol.zig
index 1a46b9cf2c..a06a19c1a4 100644
--- a/lib/std/os/uefi/protocols/absolute_pointer_protocol.zig
+++ b/lib/std/os/uefi/protocols/absolute_pointer_protocol.zig
@@ -5,8 +5,8 @@ const Status = uefi.Status;
 
 /// Protocol for touchscreens
 pub const AbsolutePointerProtocol = extern struct {
-    _reset: extern fn (*const AbsolutePointerProtocol, bool) Status,
-    _get_state: extern fn (*const AbsolutePointerProtocol, *AbsolutePointerState) Status,
+    _reset: fn (*const AbsolutePointerProtocol, bool) callconv(.C) Status,
+    _get_state: fn (*const AbsolutePointerProtocol, *AbsolutePointerState) callconv(.C) Status,
     wait_for_input: Event,
     mode: *AbsolutePointerMode,
 
diff --git a/lib/std/os/uefi/protocols/edid_override_protocol.zig b/lib/std/os/uefi/protocols/edid_override_protocol.zig
index 2c37baa7a4..efe73982e9 100644
--- a/lib/std/os/uefi/protocols/edid_override_protocol.zig
+++ b/lib/std/os/uefi/protocols/edid_override_protocol.zig
@@ -5,7 +5,7 @@ const Status = uefi.Status;
 
 /// Override EDID information
 pub const EdidOverrideProtocol = extern struct {
-    _get_edid: extern fn (*const EdidOverrideProtocol, Handle, *u32, *usize, *?[*]u8) Status,
+    _get_edid: fn (*const EdidOverrideProtocol, Handle, *u32, *usize, *?[*]u8) callconv(.C) Status,
 
     /// Returns policy information and potentially a replacement EDID for the specified video output device.
     /// attributes must be align(4)
diff --git a/lib/std/os/uefi/protocols/file_protocol.zig b/lib/std/os/uefi/protocols/file_protocol.zig
index 4331d9a38c..eacd777008 100644
--- a/lib/std/os/uefi/protocols/file_protocol.zig
+++ b/lib/std/os/uefi/protocols/file_protocol.zig
@@ -5,16 +5,16 @@ const Status = uefi.Status;
 
 pub const FileProtocol = extern struct {
     revision: u64,
-    _open: extern fn (*const FileProtocol, **const FileProtocol, [*:0]const u16, u64, u64) Status,
-    _close: extern fn (*const FileProtocol) Status,
-    _delete: extern fn (*const FileProtocol) Status,
-    _read: extern fn (*const FileProtocol, *usize, [*]u8) Status,
-    _write: extern fn (*const FileProtocol, *usize, [*]const u8) Status,
-    _get_position: extern fn (*const FileProtocol, *u64) Status,
-    _set_position: extern fn (*const FileProtocol, *const u64) Status,
-    _get_info: extern fn (*const FileProtocol, *align(8) const Guid, *const usize, [*]u8) Status,
-    _set_info: extern fn (*const FileProtocol, *align(8) const Guid, usize, [*]const u8) Status,
-    _flush: extern fn (*const FileProtocol) Status,
+    _open: fn (*const FileProtocol, **const FileProtocol, [*:0]const u16, u64, u64) callconv(.C) Status,
+    _close: fn (*const FileProtocol) callconv(.C) Status,
+    _delete: fn (*const FileProtocol) callconv(.C) Status,
+    _read: fn (*const FileProtocol, *usize, [*]u8) callconv(.C) Status,
+    _write: fn (*const FileProtocol, *usize, [*]const u8) callconv(.C) Status,
+    _get_position: fn (*const FileProtocol, *u64) callconv(.C) Status,
+    _set_position: fn (*const FileProtocol, *const u64) callconv(.C) Status,
+    _get_info: fn (*const FileProtocol, *align(8) const Guid, *const usize, [*]u8) callconv(.C) Status,
+    _set_info: fn (*const FileProtocol, *align(8) const Guid, usize, [*]const u8) callconv(.C) Status,
+    _flush: fn (*const FileProtocol) callconv(.C) Status,
 
     pub fn open(self: *const FileProtocol, new_handle: **const FileProtocol, file_name: [*:0]const u16, open_mode: u64, attributes: u64) Status {
         return self._open(self, new_handle, file_name, open_mode, attributes);
diff --git a/lib/std/os/uefi/protocols/graphics_output_protocol.zig b/lib/std/os/uefi/protocols/graphics_output_protocol.zig
index 7370f537bf..1ceccce0bf 100644
--- a/lib/std/os/uefi/protocols/graphics_output_protocol.zig
+++ b/lib/std/os/uefi/protocols/graphics_output_protocol.zig
@@ -4,9 +4,9 @@ const Status = uefi.Status;
 
 /// Graphics output
 pub const GraphicsOutputProtocol = extern struct {
-    _query_mode: extern fn (*const GraphicsOutputProtocol, u32, *usize, **GraphicsOutputModeInformation) Status,
-    _set_mode: extern fn (*const GraphicsOutputProtocol, u32) Status,
-    _blt: extern fn (*const GraphicsOutputProtocol, ?[*]GraphicsOutputBltPixel, GraphicsOutputBltOperation, usize, usize, usize, usize, usize, usize, usize) Status,
+    _query_mode: fn (*const GraphicsOutputProtocol, u32, *usize, **GraphicsOutputModeInformation) callconv(.C) Status,
+    _set_mode: fn (*const GraphicsOutputProtocol, u32) callconv(.C) Status,
+    _blt: fn (*const GraphicsOutputProtocol, ?[*]GraphicsOutputBltPixel, GraphicsOutputBltOperation, usize, usize, usize, usize, usize, usize, usize) callconv(.C) Status,
     mode: *GraphicsOutputProtocolMode,
 
     /// Returns information for an available graphics mode that the graphics device and the set of active video output devices supports.
diff --git a/lib/std/os/uefi/protocols/hii_database_protocol.zig b/lib/std/os/uefi/protocols/hii_database_protocol.zig
index c79f693f6f..e34f72c2f3 100644
--- a/lib/std/os/uefi/protocols/hii_database_protocol.zig
+++ b/lib/std/os/uefi/protocols/hii_database_protocol.zig
@@ -6,10 +6,10 @@ const hii = uefi.protocols.hii;
 /// Database manager for HII-related data structures.
 pub const HIIDatabaseProtocol = extern struct {
     _new_package_list: Status, // TODO
-    _remove_package_list: extern fn (*const HIIDatabaseProtocol, hii.HIIHandle) Status,
-    _update_package_list: extern fn (*const HIIDatabaseProtocol, hii.HIIHandle, *const hii.HIIPackageList) Status,
-    _list_package_lists: extern fn (*const HIIDatabaseProtocol, u8, ?*const Guid, *usize, [*]hii.HIIHandle) Status,
-    _export_package_lists: extern fn (*const HIIDatabaseProtocol, ?hii.HIIHandle, *usize, *hii.HIIPackageList) Status,
+    _remove_package_list: fn (*const HIIDatabaseProtocol, hii.HIIHandle) callconv(.C) Status,
+    _update_package_list: fn (*const HIIDatabaseProtocol, hii.HIIHandle, *const hii.HIIPackageList) callconv(.C) Status,
+    _list_package_lists: fn (*const HIIDatabaseProtocol, u8, ?*const Guid, *usize, [*]hii.HIIHandle) callconv(.C) Status,
+    _export_package_lists: fn (*const HIIDatabaseProtocol, ?hii.HIIHandle, *usize, *hii.HIIPackageList) callconv(.C) Status,
     _register_package_notify: Status, // TODO
     _unregister_package_notify: Status, // TODO
     _find_keyboard_layouts: Status, // TODO
diff --git a/lib/std/os/uefi/protocols/hii_popup_protocol.zig b/lib/std/os/uefi/protocols/hii_popup_protocol.zig
index 96afe21fbc..2e4f621b41 100644
--- a/lib/std/os/uefi/protocols/hii_popup_protocol.zig
+++ b/lib/std/os/uefi/protocols/hii_popup_protocol.zig
@@ -6,7 +6,7 @@ const hii = uefi.protocols.hii;
 /// Display a popup window
 pub const HIIPopupProtocol = extern struct {
     revision: u64,
-    _create_popup: extern fn (*const HIIPopupProtocol, HIIPopupStyle, HIIPopupType, hii.HIIHandle, u16, ?*HIIPopupSelection) Status,
+    _create_popup: fn (*const HIIPopupProtocol, HIIPopupStyle, HIIPopupType, hii.HIIHandle, u16, ?*HIIPopupSelection) callconv(.C) Status,
 
     /// Displays a popup window.
     pub fn createPopup(self: *const HIIPopupProtocol, style: HIIPopupStyle, popup_type: HIIPopupType, handle: hii.HIIHandle, msg: u16, user_selection: ?*HIIPopupSelection) Status {
diff --git a/lib/std/os/uefi/protocols/ip6_config_protocol.zig b/lib/std/os/uefi/protocols/ip6_config_protocol.zig
index 89ff39e8d1..99ba76aa17 100644
--- a/lib/std/os/uefi/protocols/ip6_config_protocol.zig
+++ b/lib/std/os/uefi/protocols/ip6_config_protocol.zig
@@ -4,10 +4,10 @@ const Event = uefi.Event;
 const Status = uefi.Status;
 
 pub const Ip6ConfigProtocol = extern struct {
-    _set_data: extern fn (*const Ip6ConfigProtocol, Ip6ConfigDataType, usize, *const c_void) Status,
-    _get_data: extern fn (*const Ip6ConfigProtocol, Ip6ConfigDataType, *usize, ?*const c_void) Status,
-    _register_data_notify: extern fn (*const Ip6ConfigProtocol, Ip6ConfigDataType, Event) Status,
-    _unregister_data_notify: extern fn (*const Ip6ConfigProtocol, Ip6ConfigDataType, Event) Status,
+    _set_data: fn (*const Ip6ConfigProtocol, Ip6ConfigDataType, usize, *const c_void) callconv(.C) Status,
+    _get_data: fn (*const Ip6ConfigProtocol, Ip6ConfigDataType, *usize, ?*const c_void) callconv(.C) Status,
+    _register_data_notify: fn (*const Ip6ConfigProtocol, Ip6ConfigDataType, Event) callconv(.C) Status,
+    _unregister_data_notify: fn (*const Ip6ConfigProtocol, Ip6ConfigDataType, Event) callconv(.C) Status,
 
     pub fn setData(self: *const Ip6ConfigProtocol, data_type: Ip6ConfigDataType, data_size: usize, data: *const c_void) Status {
         return self._set_data(self, data_type, data_size, data);
diff --git a/lib/std/os/uefi/protocols/ip6_protocol.zig b/lib/std/os/uefi/protocols/ip6_protocol.zig
index f9a5c23d3c..b39ae60b2a 100644
--- a/lib/std/os/uefi/protocols/ip6_protocol.zig
+++ b/lib/std/os/uefi/protocols/ip6_protocol.zig
@@ -7,15 +7,15 @@ const ManagedNetworkConfigData = uefi.protocols.ManagedNetworkConfigData;
 const SimpleNetworkMode = uefi.protocols.SimpleNetworkMode;
 
 pub const Ip6Protocol = extern struct {
-    _get_mode_data: extern fn (*const Ip6Protocol, ?*Ip6ModeData, ?*ManagedNetworkConfigData, ?*SimpleNetworkMode) Status,
-    _configure: extern fn (*const Ip6Protocol, ?*const Ip6ConfigData) Status,
-    _groups: extern fn (*const Ip6Protocol, bool, ?*const Ip6Address) Status,
-    _routes: extern fn (*const Ip6Protocol, bool, ?*const Ip6Address, u8, ?*const Ip6Address) Status,
-    _neighbors: extern fn (*const Ip6Protocol, bool, *const Ip6Address, ?*const MacAddress, u32, bool) Status,
-    _transmit: extern fn (*const Ip6Protocol, *Ip6CompletionToken) Status,
-    _receive: extern fn (*const Ip6Protocol, *Ip6CompletionToken) Status,
-    _cancel: extern fn (*const Ip6Protocol, ?*Ip6CompletionToken) Status,
-    _poll: extern fn (*const Ip6Protocol) Status,
+    _get_mode_data: fn (*const Ip6Protocol, ?*Ip6ModeData, ?*ManagedNetworkConfigData, ?*SimpleNetworkMode) callconv(.C) Status,
+    _configure: fn (*const Ip6Protocol, ?*const Ip6ConfigData) callconv(.C) Status,
+    _groups: fn (*const Ip6Protocol, bool, ?*const Ip6Address) callconv(.C) Status,
+    _routes: fn (*const Ip6Protocol, bool, ?*const Ip6Address, u8, ?*const Ip6Address) callconv(.C) Status,
+    _neighbors: fn (*const Ip6Protocol, bool, *const Ip6Address, ?*const MacAddress, u32, bool) callconv(.C) Status,
+    _transmit: fn (*const Ip6Protocol, *Ip6CompletionToken) callconv(.C) Status,
+    _receive: fn (*const Ip6Protocol, *Ip6CompletionToken) callconv(.C) Status,
+    _cancel: fn (*const Ip6Protocol, ?*Ip6CompletionToken) callconv(.C) Status,
+    _poll: fn (*const Ip6Protocol) callconv(.C) Status,
 
     /// Gets the current operational settings for this instance of the EFI IPv6 Protocol driver.
     pub fn getModeData(self: *const Ip6Protocol, ip6_mode_data: ?*Ip6ModeData, mnp_config_data: ?*ManagedNetworkConfigData, snp_mode_data: ?*SimpleNetworkMode) Status {
diff --git a/lib/std/os/uefi/protocols/ip6_service_binding_protocol.zig b/lib/std/os/uefi/protocols/ip6_service_binding_protocol.zig
index 030ae5cae2..97ab1a431c 100644
--- a/lib/std/os/uefi/protocols/ip6_service_binding_protocol.zig
+++ b/lib/std/os/uefi/protocols/ip6_service_binding_protocol.zig
@@ -4,8 +4,8 @@ const Guid = uefi.Guid;
 const Status = uefi.Status;
 
 pub const Ip6ServiceBindingProtocol = extern struct {
-    _create_child: extern fn (*const Ip6ServiceBindingProtocol, *?Handle) Status,
-    _destroy_child: extern fn (*const Ip6ServiceBindingProtocol, Handle) Status,
+    _create_child: fn (*const Ip6ServiceBindingProtocol, *?Handle) callconv(.C) Status,
+    _destroy_child: fn (*const Ip6ServiceBindingProtocol, Handle) callconv(.C) Status,
 
     pub fn createChild(self: *const Ip6ServiceBindingProtocol, handle: *?Handle) Status {
         return self._create_child(self, handle);
diff --git a/lib/std/os/uefi/protocols/loaded_image_protocol.zig b/lib/std/os/uefi/protocols/loaded_image_protocol.zig
index cff2bdccc0..b8afcb1063 100644
--- a/lib/std/os/uefi/protocols/loaded_image_protocol.zig
+++ b/lib/std/os/uefi/protocols/loaded_image_protocol.zig
@@ -19,7 +19,7 @@ pub const LoadedImageProtocol = extern struct {
     image_size: u64,
     image_code_type: MemoryType,
     image_data_type: MemoryType,
-    _unload: extern fn (*const LoadedImageProtocol, Handle) Status,
+    _unload: fn (*const LoadedImageProtocol, Handle) callconv(.C) Status,
 
     /// Unloads an image from memory.
     pub fn unload(self: *const LoadedImageProtocol, handle: Handle) Status {
diff --git a/lib/std/os/uefi/protocols/managed_network_protocol.zig b/lib/std/os/uefi/protocols/managed_network_protocol.zig
index 60dc6996ad..34ef6c40fa 100644
--- a/lib/std/os/uefi/protocols/managed_network_protocol.zig
+++ b/lib/std/os/uefi/protocols/managed_network_protocol.zig
@@ -7,14 +7,14 @@ const SimpleNetworkMode = uefi.protocols.SimpleNetworkMode;
 const MacAddress = uefi.protocols.MacAddress;
 
 pub const ManagedNetworkProtocol = extern struct {
-    _get_mode_data: extern fn (*const ManagedNetworkProtocol, ?*ManagedNetworkConfigData, ?*SimpleNetworkMode) Status,
-    _configure: extern fn (*const ManagedNetworkProtocol, ?*const ManagedNetworkConfigData) Status,
-    _mcast_ip_to_mac: extern fn (*const ManagedNetworkProtocol, bool, *const c_void, *MacAddress) Status,
-    _groups: extern fn (*const ManagedNetworkProtocol, bool, ?*const MacAddress) Status,
-    _transmit: extern fn (*const ManagedNetworkProtocol, *const ManagedNetworkCompletionToken) Status,
-    _receive: extern fn (*const ManagedNetworkProtocol, *const ManagedNetworkCompletionToken) Status,
-    _cancel: extern fn (*const ManagedNetworkProtocol, ?*const ManagedNetworkCompletionToken) Status,
-    _poll: extern fn (*const ManagedNetworkProtocol) usize,
+    _get_mode_data: fn (*const ManagedNetworkProtocol, ?*ManagedNetworkConfigData, ?*SimpleNetworkMode) callconv(.C) Status,
+    _configure: fn (*const ManagedNetworkProtocol, ?*const ManagedNetworkConfigData) callconv(.C) Status,
+    _mcast_ip_to_mac: fn (*const ManagedNetworkProtocol, bool, *const c_void, *MacAddress) callconv(.C) Status,
+    _groups: fn (*const ManagedNetworkProtocol, bool, ?*const MacAddress) callconv(.C) Status,
+    _transmit: fn (*const ManagedNetworkProtocol, *const ManagedNetworkCompletionToken) callconv(.C) Status,
+    _receive: fn (*const ManagedNetworkProtocol, *const ManagedNetworkCompletionToken) callconv(.C) Status,
+    _cancel: fn (*const ManagedNetworkProtocol, ?*const ManagedNetworkCompletionToken) callconv(.C) Status,
+    _poll: fn (*const ManagedNetworkProtocol) callconv(.C) usize,
 
     /// Returns the operational parameters for the current MNP child driver.
     /// May also support returning the underlying SNP driver mode data.
diff --git a/lib/std/os/uefi/protocols/managed_network_service_binding_protocol.zig b/lib/std/os/uefi/protocols/managed_network_service_binding_protocol.zig
index ea8bd470c3..e9657e4456 100644
--- a/lib/std/os/uefi/protocols/managed_network_service_binding_protocol.zig
+++ b/lib/std/os/uefi/protocols/managed_network_service_binding_protocol.zig
@@ -4,8 +4,8 @@ const Guid = uefi.Guid;
 const Status = uefi.Status;
 
 pub const ManagedNetworkServiceBindingProtocol = extern struct {
-    _create_child: extern fn (*const ManagedNetworkServiceBindingProtocol, *?Handle) Status,
-    _destroy_child: extern fn (*const ManagedNetworkServiceBindingProtocol, Handle) Status,
+    _create_child: fn (*const ManagedNetworkServiceBindingProtocol, *?Handle) callconv(.C) Status,
+    _destroy_child: fn (*const ManagedNetworkServiceBindingProtocol, Handle) callconv(.C) Status,
 
     pub fn createChild(self: *const ManagedNetworkServiceBindingProtocol, handle: *?Handle) Status {
         return self._create_child(self, handle);
diff --git a/lib/std/os/uefi/protocols/rng_protocol.zig b/lib/std/os/uefi/protocols/rng_protocol.zig
index 4d5dd496af..a32b202f44 100644
--- a/lib/std/os/uefi/protocols/rng_protocol.zig
+++ b/lib/std/os/uefi/protocols/rng_protocol.zig
@@ -4,8 +4,8 @@ const Status = uefi.Status;
 
 /// Random Number Generator protocol
 pub const RNGProtocol = extern struct {
-    _get_info: extern fn (*const RNGProtocol, *usize, [*]align(8) Guid) Status,
-    _get_rng: extern fn (*const RNGProtocol, ?*align(8) const Guid, usize, [*]u8) Status,
+    _get_info: fn (*const RNGProtocol, *usize, [*]align(8) Guid) callconv(.C) Status,
+    _get_rng: fn (*const RNGProtocol, ?*align(8) const Guid, usize, [*]u8) callconv(.C) Status,
 
     /// Returns information about the random number generation implementation.
     pub fn getInfo(self: *const RNGProtocol, list_size: *usize, list: [*]align(8) Guid) Status {
diff --git a/lib/std/os/uefi/protocols/simple_file_system_protocol.zig b/lib/std/os/uefi/protocols/simple_file_system_protocol.zig
index 31da02595a..119c1e6587 100644
--- a/lib/std/os/uefi/protocols/simple_file_system_protocol.zig
+++ b/lib/std/os/uefi/protocols/simple_file_system_protocol.zig
@@ -5,7 +5,7 @@ const Status = uefi.Status;
 
 pub const SimpleFileSystemProtocol = extern struct {
     revision: u64,
-    _open_volume: extern fn (*const SimpleFileSystemProtocol, **const FileProtocol) Status,
+    _open_volume: fn (*const SimpleFileSystemProtocol, **const FileProtocol) callconv(.C) Status,
 
     pub fn openVolume(self: *const SimpleFileSystemProtocol, root: **const FileProtocol) Status {
         return self._open_volume(self, root);
diff --git a/lib/std/os/uefi/protocols/simple_network_protocol.zig b/lib/std/os/uefi/protocols/simple_network_protocol.zig
index a0d85b06d1..ac7446036e 100644
--- a/lib/std/os/uefi/protocols/simple_network_protocol.zig
+++ b/lib/std/os/uefi/protocols/simple_network_protocol.zig
@@ -5,19 +5,19 @@ const Status = uefi.Status;
 
 pub const SimpleNetworkProtocol = extern struct {
     revision: u64,
-    _start: extern fn (*const SimpleNetworkProtocol) Status,
-    _stop: extern fn (*const SimpleNetworkProtocol) Status,
-    _initialize: extern fn (*const SimpleNetworkProtocol, usize, usize) Status,
-    _reset: extern fn (*const SimpleNetworkProtocol, bool) Status,
-    _shutdown: extern fn (*const SimpleNetworkProtocol) Status,
-    _receive_filters: extern fn (*const SimpleNetworkProtocol, SimpleNetworkReceiveFilter, SimpleNetworkReceiveFilter, bool, usize, ?[*]const MacAddress) Status,
-    _station_address: extern fn (*const SimpleNetworkProtocol, bool, ?*const MacAddress) Status,
-    _statistics: extern fn (*const SimpleNetworkProtocol, bool, ?*usize, ?*NetworkStatistics) Status,
-    _mcast_ip_to_mac: extern fn (*const SimpleNetworkProtocol, bool, *const c_void, *MacAddress) Status,
-    _nvdata: extern fn (*const SimpleNetworkProtocol, bool, usize, usize, [*]u8) Status,
-    _get_status: extern fn (*const SimpleNetworkProtocol, *SimpleNetworkInterruptStatus, ?*?[*]u8) Status,
-    _transmit: extern fn (*const SimpleNetworkProtocol, usize, usize, [*]const u8, ?*const MacAddress, ?*const MacAddress, ?*const u16) Status,
-    _receive: extern fn (*const SimpleNetworkProtocol, ?*usize, *usize, [*]u8, ?*MacAddress, ?*MacAddress, ?*u16) Status,
+    _start: fn (*const SimpleNetworkProtocol) callconv(.C) Status,
+    _stop: fn (*const SimpleNetworkProtocol) callconv(.C) Status,
+    _initialize: fn (*const SimpleNetworkProtocol, usize, usize) callconv(.C) Status,
+    _reset: fn (*const SimpleNetworkProtocol, bool) callconv(.C) Status,
+    _shutdown: fn (*const SimpleNetworkProtocol) callconv(.C) Status,
+    _receive_filters: fn (*const SimpleNetworkProtocol, SimpleNetworkReceiveFilter, SimpleNetworkReceiveFilter, bool, usize, ?[*]const MacAddress) callconv(.C) Status,
+    _station_address: fn (*const SimpleNetworkProtocol, bool, ?*const MacAddress) callconv(.C) Status,
+    _statistics: fn (*const SimpleNetworkProtocol, bool, ?*usize, ?*NetworkStatistics) callconv(.C) Status,
+    _mcast_ip_to_mac: fn (*const SimpleNetworkProtocol, bool, *const c_void, *MacAddress) callconv(.C) Status,
+    _nvdata: fn (*const SimpleNetworkProtocol, bool, usize, usize, [*]u8) callconv(.C) Status,
+    _get_status: fn (*const SimpleNetworkProtocol, *SimpleNetworkInterruptStatus, ?*?[*]u8) callconv(.C) Status,
+    _transmit: fn (*const SimpleNetworkProtocol, usize, usize, [*]const u8, ?*const MacAddress, ?*const MacAddress, ?*const u16) callconv(.C) Status,
+    _receive: fn (*const SimpleNetworkProtocol, ?*usize, *usize, [*]u8, ?*MacAddress, ?*MacAddress, ?*u16) callconv(.C) Status,
     wait_for_packet: Event,
     mode: *SimpleNetworkMode,
 
diff --git a/lib/std/os/uefi/protocols/simple_pointer_protocol.zig b/lib/std/os/uefi/protocols/simple_pointer_protocol.zig
index 2d1c7d4504..d217ab5930 100644
--- a/lib/std/os/uefi/protocols/simple_pointer_protocol.zig
+++ b/lib/std/os/uefi/protocols/simple_pointer_protocol.zig
@@ -5,8 +5,8 @@ const Status = uefi.Status;
 
 /// Protocol for mice
 pub const SimplePointerProtocol = struct {
-    _reset: extern fn (*const SimplePointerProtocol, bool) Status,
-    _get_state: extern fn (*const SimplePointerProtocol, *SimplePointerState) Status,
+    _reset: fn (*const SimplePointerProtocol, bool) callconv(.C) Status,
+    _get_state: fn (*const SimplePointerProtocol, *SimplePointerState) callconv(.C) Status,
     wait_for_input: Event,
     mode: *SimplePointerMode,
 
diff --git a/lib/std/os/uefi/protocols/simple_text_input_ex_protocol.zig b/lib/std/os/uefi/protocols/simple_text_input_ex_protocol.zig
index c361ffa9a1..4a2b098e61 100644
--- a/lib/std/os/uefi/protocols/simple_text_input_ex_protocol.zig
+++ b/lib/std/os/uefi/protocols/simple_text_input_ex_protocol.zig
@@ -5,12 +5,12 @@ const Status = uefi.Status;
 
 /// Character input devices, e.g. Keyboard
 pub const SimpleTextInputExProtocol = extern struct {
-    _reset: extern fn (*const SimpleTextInputExProtocol, bool) Status,
-    _read_key_stroke_ex: extern fn (*const SimpleTextInputExProtocol, *KeyData) Status,
+    _reset: fn (*const SimpleTextInputExProtocol, bool) callconv(.C) Status,
+    _read_key_stroke_ex: fn (*const SimpleTextInputExProtocol, *KeyData) callconv(.C) Status,
     wait_for_key_ex: Event,
-    _set_state: extern fn (*const SimpleTextInputExProtocol, *const u8) Status,
-    _register_key_notify: extern fn (*const SimpleTextInputExProtocol, *const KeyData, extern fn (*const KeyData) usize, **c_void) Status,
-    _unregister_key_notify: extern fn (*const SimpleTextInputExProtocol, *const c_void) Status,
+    _set_state: fn (*const SimpleTextInputExProtocol, *const u8) callconv(.C) Status,
+    _register_key_notify: fn (*const SimpleTextInputExProtocol, *const KeyData, fn (*const KeyData) callconv(.C) usize, **c_void) callconv(.C) Status,
+    _unregister_key_notify: fn (*const SimpleTextInputExProtocol, *const c_void) callconv(.C) Status,
 
     /// Resets the input device hardware.
     pub fn reset(self: *const SimpleTextInputExProtocol, verify: bool) Status {
@@ -28,7 +28,7 @@ pub const SimpleTextInputExProtocol = extern struct {
     }
 
     /// Register a notification function for a particular keystroke for the input device.
-    pub fn registerKeyNotify(self: *const SimpleTextInputExProtocol, key_data: *const KeyData, notify: extern fn (*const KeyData) usize, handle: **c_void) Status {
+    pub fn registerKeyNotify(self: *const SimpleTextInputExProtocol, key_data: *const KeyData, notify: fn (*const KeyData) callconv(.C) usize, handle: **c_void) Status {
         return self._register_key_notify(self, key_data, notify, handle);
     }
 
diff --git a/lib/std/os/uefi/protocols/simple_text_input_protocol.zig b/lib/std/os/uefi/protocols/simple_text_input_protocol.zig
index fdae001145..58ed071331 100644
--- a/lib/std/os/uefi/protocols/simple_text_input_protocol.zig
+++ b/lib/std/os/uefi/protocols/simple_text_input_protocol.zig
@@ -6,8 +6,8 @@ const Status = uefi.Status;
 
 /// Character input devices, e.g. Keyboard
 pub const SimpleTextInputProtocol = extern struct {
-    _reset: extern fn (*const SimpleTextInputProtocol, bool) usize,
-    _read_key_stroke: extern fn (*const SimpleTextInputProtocol, *InputKey) Status,
+    _reset: fn (*const SimpleTextInputProtocol, bool) callconv(.C) usize,
+    _read_key_stroke: fn (*const SimpleTextInputProtocol, *InputKey) callconv(.C) Status,
     wait_for_key: Event,
 
     /// Resets the input device hardware.
diff --git a/lib/std/os/uefi/protocols/simple_text_output_protocol.zig b/lib/std/os/uefi/protocols/simple_text_output_protocol.zig
index 09f3cb1cd2..84f540cb78 100644
--- a/lib/std/os/uefi/protocols/simple_text_output_protocol.zig
+++ b/lib/std/os/uefi/protocols/simple_text_output_protocol.zig
@@ -4,15 +4,15 @@ const Status = uefi.Status;
 
 /// Character output devices
 pub const SimpleTextOutputProtocol = extern struct {
-    _reset: extern fn (*const SimpleTextOutputProtocol, bool) Status,
-    _output_string: extern fn (*const SimpleTextOutputProtocol, [*:0]const u16) Status,
-    _test_string: extern fn (*const SimpleTextOutputProtocol, [*:0]const u16) Status,
-    _query_mode: extern fn (*const SimpleTextOutputProtocol, usize, *usize, *usize) Status,
-    _set_mode: extern fn (*const SimpleTextOutputProtocol, usize) Status,
-    _set_attribute: extern fn (*const SimpleTextOutputProtocol, usize) Status,
-    _clear_screen: extern fn (*const SimpleTextOutputProtocol) Status,
-    _set_cursor_position: extern fn (*const SimpleTextOutputProtocol, usize, usize) Status,
-    _enable_cursor: extern fn (*const SimpleTextOutputProtocol, bool) Status,
+    _reset: fn (*const SimpleTextOutputProtocol, bool) callconv(.C) Status,
+    _output_string: fn (*const SimpleTextOutputProtocol, [*:0]const u16) callconv(.C) Status,
+    _test_string: fn (*const SimpleTextOutputProtocol, [*:0]const u16) callconv(.C) Status,
+    _query_mode: fn (*const SimpleTextOutputProtocol, usize, *usize, *usize) callconv(.C) Status,
+    _set_mode: fn (*const SimpleTextOutputProtocol, usize) callconv(.C) Status,
+    _set_attribute: fn (*const SimpleTextOutputProtocol, usize) callconv(.C) Status,
+    _clear_screen: fn (*const SimpleTextOutputProtocol) callconv(.C) Status,
+    _set_cursor_position: fn (*const SimpleTextOutputProtocol, usize, usize) callconv(.C) Status,
+    _enable_cursor: fn (*const SimpleTextOutputProtocol, bool) callconv(.C) Status,
     mode: *SimpleTextOutputMode,
 
     /// Resets the text output device hardware.
diff --git a/lib/std/os/uefi/protocols/udp6_protocol.zig b/lib/std/os/uefi/protocols/udp6_protocol.zig
index f0ab2789f3..46c76beaa6 100644
--- a/lib/std/os/uefi/protocols/udp6_protocol.zig
+++ b/lib/std/os/uefi/protocols/udp6_protocol.zig
@@ -9,13 +9,13 @@ const ManagedNetworkConfigData = uefi.protocols.ManagedNetworkConfigData;
 const SimpleNetworkMode = uefi.protocols.SimpleNetworkMode;
 
 pub const Udp6Protocol = extern struct {
-    _get_mode_data: extern fn (*const Udp6Protocol, ?*Udp6ConfigData, ?*Ip6ModeData, ?*ManagedNetworkConfigData, ?*SimpleNetworkMode) Status,
-    _configure: extern fn (*const Udp6Protocol, ?*const Udp6ConfigData) Status,
-    _groups: extern fn (*const Udp6Protocol, bool, ?*const Ip6Address) Status,
-    _transmit: extern fn (*const Udp6Protocol, *Udp6CompletionToken) Status,
-    _receive: extern fn (*const Udp6Protocol, *Udp6CompletionToken) Status,
-    _cancel: extern fn (*const Udp6Protocol, ?*Udp6CompletionToken) Status,
-    _poll: extern fn (*const Udp6Protocol) Status,
+    _get_mode_data: fn (*const Udp6Protocol, ?*Udp6ConfigData, ?*Ip6ModeData, ?*ManagedNetworkConfigData, ?*SimpleNetworkMode) callconv(.C) Status,
+    _configure: fn (*const Udp6Protocol, ?*const Udp6ConfigData) callconv(.C) Status,
+    _groups: fn (*const Udp6Protocol, bool, ?*const Ip6Address) callconv(.C) Status,
+    _transmit: fn (*const Udp6Protocol, *Udp6CompletionToken) callconv(.C) Status,
+    _receive: fn (*const Udp6Protocol, *Udp6CompletionToken) callconv(.C) Status,
+    _cancel: fn (*const Udp6Protocol, ?*Udp6CompletionToken) callconv(.C) Status,
+    _poll: fn (*const Udp6Protocol) callconv(.C) Status,
 
     pub fn getModeData(self: *const Udp6Protocol, udp6_config_data: ?*Udp6ConfigData, ip6_mode_data: ?*Ip6ModeData, mnp_config_data: ?*ManagedNetworkConfigData, snp_mode_data: ?*SimpleNetworkMode) Status {
         return self._get_mode_data(self, udp6_config_data, ip6_mode_data, mnp_config_data, snp_mode_data);
diff --git a/lib/std/os/uefi/protocols/udp6_service_binding_protocol.zig b/lib/std/os/uefi/protocols/udp6_service_binding_protocol.zig
index 9a7a67807c..811692adc3 100644
--- a/lib/std/os/uefi/protocols/udp6_service_binding_protocol.zig
+++ b/lib/std/os/uefi/protocols/udp6_service_binding_protocol.zig
@@ -4,8 +4,8 @@ const Guid = uefi.Guid;
 const Status = uefi.Status;
 
 pub const Udp6ServiceBindingProtocol = extern struct {
-    _create_child: extern fn (*const Udp6ServiceBindingProtocol, *?Handle) Status,
-    _destroy_child: extern fn (*const Udp6ServiceBindingProtocol, Handle) Status,
+    _create_child: fn (*const Udp6ServiceBindingProtocol, *?Handle) callconv(.C) Status,
+    _destroy_child: fn (*const Udp6ServiceBindingProtocol, Handle) callconv(.C) Status,
 
     pub fn createChild(self: *const Udp6ServiceBindingProtocol, handle: *?Handle) Status {
         return self._create_child(self, handle);
diff --git a/lib/std/os/uefi/tables/boot_services.zig b/lib/std/os/uefi/tables/boot_services.zig
index 1969b46403..a1d2c1ca59 100644
--- a/lib/std/os/uefi/tables/boot_services.zig
+++ b/lib/std/os/uefi/tables/boot_services.zig
@@ -21,117 +21,117 @@ pub const BootServices = extern struct {
     hdr: TableHeader,
 
     /// Raises a task's priority level and returns its previous level.
-    raiseTpl: extern fn (usize) usize,
+    raiseTpl: fn (usize) callconv(.C) usize,
 
     /// Restores a task's priority level to its previous value.
-    restoreTpl: extern fn (usize) void,
+    restoreTpl: fn (usize) callconv(.C) void,
 
     /// Allocates memory pages from the system.
-    allocatePages: extern fn (AllocateType, MemoryType, usize, *[*]align(4096) u8) Status,
+    allocatePages: fn (AllocateType, MemoryType, usize, *[*]align(4096) u8) callconv(.C) Status,
 
     /// Frees memory pages.
-    freePages: extern fn ([*]align(4096) u8, usize) Status,
+    freePages: fn ([*]align(4096) u8, usize) callconv(.C) Status,
 
     /// Returns the current memory map.
-    getMemoryMap: extern fn (*usize, [*]MemoryDescriptor, *usize, *usize, *u32) Status,
+    getMemoryMap: fn (*usize, [*]MemoryDescriptor, *usize, *usize, *u32) callconv(.C) Status,
 
     /// Allocates pool memory.
-    allocatePool: extern fn (MemoryType, usize, *[*]align(8) u8) Status,
+    allocatePool: fn (MemoryType, usize, *[*]align(8) u8) callconv(.C) Status,
 
     /// Returns pool memory to the system.
-    freePool: extern fn ([*]align(8) u8) Status,
+    freePool: fn ([*]align(8) u8) callconv(.C) Status,
 
     /// Creates an event.
-    createEvent: extern fn (u32, usize, ?extern fn (Event, ?*c_void) void, ?*const c_void, *Event) Status,
+    createEvent: fn (u32, usize, ?fn (Event, ?*c_void) callconv(.C) void, ?*const c_void, *Event) callconv(.C) Status,
 
     /// Sets the type of timer and the trigger time for a timer event.
-    setTimer: extern fn (Event, TimerDelay, u64) Status,
+    setTimer: fn (Event, TimerDelay, u64) callconv(.C) Status,
 
     /// Stops execution until an event is signaled.
-    waitForEvent: extern fn (usize, [*]const Event, *usize) Status,
+    waitForEvent: fn (usize, [*]const Event, *usize) callconv(.C) Status,
 
     /// Signals an event.
-    signalEvent: extern fn (Event) Status,
+    signalEvent: fn (Event) callconv(.C) Status,
 
     /// Closes an event.
-    closeEvent: extern fn (Event) Status,
+    closeEvent: fn (Event) callconv(.C) Status,
 
     /// Checks whether an event is in the signaled state.
-    checkEvent: extern fn (Event) Status,
+    checkEvent: fn (Event) callconv(.C) Status,
 
     installProtocolInterface: Status, // TODO
     reinstallProtocolInterface: Status, // TODO
     uninstallProtocolInterface: Status, // TODO
 
     /// Queries a handle to determine if it supports a specified protocol.
-    handleProtocol: extern fn (Handle, *align(8) const Guid, *?*c_void) Status,
+    handleProtocol: fn (Handle, *align(8) const Guid, *?*c_void) callconv(.C) Status,
 
     reserved: *c_void,
 
     registerProtocolNotify: Status, // TODO
 
     /// Returns an array of handles that support a specified protocol.
-    locateHandle: extern fn (LocateSearchType, ?*align(8) const Guid, ?*const c_void, *usize, [*]Handle) Status,
+    locateHandle: fn (LocateSearchType, ?*align(8) const Guid, ?*const c_void, *usize, [*]Handle) callconv(.C) Status,
 
     locateDevicePath: Status, // TODO
     installConfigurationTable: Status, // TODO
 
     /// Loads an EFI image into memory.
-    loadImage: extern fn (bool, Handle, ?*const DevicePathProtocol, ?[*]const u8, usize, *?Handle) Status,
+    loadImage: fn (bool, Handle, ?*const DevicePathProtocol, ?[*]const u8, usize, *?Handle) callconv(.C) Status,
 
     /// Transfers control to a loaded image's entry point.
-    startImage: extern fn (Handle, ?*usize, ?*[*]u16) Status,
+    startImage: fn (Handle, ?*usize, ?*[*]u16) callconv(.C) Status,
 
     /// Terminates a loaded EFI image and returns control to boot services.
-    exit: extern fn (Handle, Status, usize, ?*const c_void) Status,
+    exit: fn (Handle, Status, usize, ?*const c_void) callconv(.C) Status,
 
     /// Unloads an image.
-    unloadImage: extern fn (Handle) Status,
+    unloadImage: fn (Handle) callconv(.C) Status,
 
     /// Terminates all boot services.
-    exitBootServices: extern fn (Handle, usize) Status,
+    exitBootServices: fn (Handle, usize) callconv(.C) Status,
 
     /// Returns a monotonically increasing count for the platform.
-    getNextMonotonicCount: extern fn (*u64) Status,
+    getNextMonotonicCount: fn (*u64) callconv(.C) Status,
 
     /// Induces a fine-grained stall.
-    stall: extern fn (usize) Status,
+    stall: fn (usize) callconv(.C) Status,
 
     /// Sets the system's watchdog timer.
-    setWatchdogTimer: extern fn (usize, u64, usize, ?[*]const u16) Status,
+    setWatchdogTimer: fn (usize, u64, usize, ?[*]const u16) callconv(.C) Status,
 
     connectController: Status, // TODO
     disconnectController: Status, // TODO
 
     /// Queries a handle to determine if it supports a specified protocol.
-    openProtocol: extern fn (Handle, *align(8) const Guid, *?*c_void, ?Handle, ?Handle, OpenProtocolAttributes) Status,
+    openProtocol: fn (Handle, *align(8) const Guid, *?*c_void, ?Handle, ?Handle, OpenProtocolAttributes) callconv(.C) Status,
 
     /// Closes a protocol on a handle that was opened using openProtocol().
-    closeProtocol: extern fn (Handle, *align(8) const Guid, Handle, ?Handle) Status,
+    closeProtocol: fn (Handle, *align(8) const Guid, Handle, ?Handle) callconv(.C) Status,
 
     /// Retrieves the list of agents that currently have a protocol interface opened.
-    openProtocolInformation: extern fn (Handle, *align(8) const Guid, *[*]ProtocolInformationEntry, *usize) Status,
+    openProtocolInformation: fn (Handle, *align(8) const Guid, *[*]ProtocolInformationEntry, *usize) callconv(.C) Status,
 
     /// Retrieves the list of protocol interface GUIDs that are installed on a handle in a buffer allocated from pool.
-    protocolsPerHandle: extern fn (Handle, *[*]*align(8) const Guid, *usize) Status,
+    protocolsPerHandle: fn (Handle, *[*]*align(8) const Guid, *usize) callconv(.C) Status,
 
     /// Returns an array of handles that support the requested protocol in a buffer allocated from pool.
-    locateHandleBuffer: extern fn (LocateSearchType, ?*align(8) const Guid, ?*const c_void, *usize, *[*]Handle) Status,
+    locateHandleBuffer: fn (LocateSearchType, ?*align(8) const Guid, ?*const c_void, *usize, *[*]Handle) callconv(.C) Status,
 
     /// Returns the first protocol instance that matches the given protocol.
-    locateProtocol: extern fn (*align(8) const Guid, ?*const c_void, *?*c_void) Status,
+    locateProtocol: fn (*align(8) const Guid, ?*const c_void, *?*c_void) callconv(.C) Status,
 
     installMultipleProtocolInterfaces: Status, // TODO
     uninstallMultipleProtocolInterfaces: Status, // TODO
 
     /// Computes and returns a 32-bit CRC for a data buffer.
-    calculateCrc32: extern fn ([*]const u8, usize, *u32) Status,
+    calculateCrc32: fn ([*]const u8, usize, *u32) callconv(.C) Status,
 
     /// Copies the contents of one buffer to another buffer
-    copyMem: extern fn ([*]u8, [*]const u8, usize) void,
+    copyMem: fn ([*]u8, [*]const u8, usize) callconv(.C) void,
 
     /// Fills a buffer with a specified value
-    setMem: extern fn ([*]u8, usize, u8) void,
+    setMem: fn ([*]u8, usize, u8) callconv(.C) void,
 
     createEventEx: Status, // TODO
 
diff --git a/lib/std/os/uefi/tables/runtime_services.zig b/lib/std/os/uefi/tables/runtime_services.zig
index 1f0c7efad4..981e07275b 100644
--- a/lib/std/os/uefi/tables/runtime_services.zig
+++ b/lib/std/os/uefi/tables/runtime_services.zig
@@ -17,7 +17,7 @@ pub const RuntimeServices = extern struct {
     hdr: TableHeader,
 
     /// Returns the current time and date information, and the time-keeping capabilities of the hardware platform.
-    getTime: extern fn (*uefi.Time, ?*TimeCapabilities) Status,
+    getTime: fn (*uefi.Time, ?*TimeCapabilities) callconv(.C) Status,
 
     setTime: Status, // TODO
     getWakeupTime: Status, // TODO
@@ -26,18 +26,18 @@ pub const RuntimeServices = extern struct {
     convertPointer: Status, // TODO
 
     /// Returns the value of a variable.
-    getVariable: extern fn ([*:0]const u16, *align(8) const Guid, ?*u32, *usize, ?*c_void) Status,
+    getVariable: fn ([*:0]const u16, *align(8) const Guid, ?*u32, *usize, ?*c_void) callconv(.C) Status,
 
     /// Enumerates the current variable names.
-    getNextVariableName: extern fn (*usize, [*:0]u16, *align(8) Guid) Status,
+    getNextVariableName: fn (*usize, [*:0]u16, *align(8) Guid) callconv(.C) Status,
 
     /// Sets the value of a variable.
-    setVariable: extern fn ([*:0]const u16, *align(8) const Guid, u32, usize, *c_void) Status,
+    setVariable: fn ([*:0]const u16, *align(8) const Guid, u32, usize, *c_void) callconv(.C) Status,
 
     getNextHighMonotonicCount: Status, // TODO
 
     /// Resets the entire platform.
-    resetSystem: extern fn (ResetType, Status, usize, ?*const c_void) noreturn,
+    resetSystem: fn (ResetType, Status, usize, ?*const c_void) callconv(.C) noreturn,
 
     updateCapsule: Status, // TODO
     queryCapsuleCapabilities: Status, // TODO
diff --git a/lib/std/os/windows/bits.zig b/lib/std/os/windows/bits.zig
index a1a60b1798..191e8deded 100644
--- a/lib/std/os/windows/bits.zig
+++ b/lib/std/os/windows/bits.zig
@@ -627,7 +627,7 @@ pub const MEM_RESERVE_PLACEHOLDERS = 0x2;
 pub const MEM_DECOMMIT = 0x4000;
 pub const MEM_RELEASE = 0x8000;
 
-pub const PTHREAD_START_ROUTINE = extern fn (LPVOID) DWORD;
+pub const PTHREAD_START_ROUTINE = fn (LPVOID) callconv(.C) DWORD;
 pub const LPTHREAD_START_ROUTINE = PTHREAD_START_ROUTINE;
 
 pub const WIN32_FIND_DATAW = extern struct {
@@ -784,7 +784,7 @@ pub const IMAGE_TLS_DIRECTORY = extern struct {
 pub const IMAGE_TLS_DIRECTORY64 = IMAGE_TLS_DIRECTORY;
 pub const IMAGE_TLS_DIRECTORY32 = IMAGE_TLS_DIRECTORY;
 
-pub const PIMAGE_TLS_CALLBACK = ?extern fn (PVOID, DWORD, PVOID) void;
+pub const PIMAGE_TLS_CALLBACK = ?fn (PVOID, DWORD, PVOID) callconv(.C) void;
 
 pub const PROV_RSA_FULL = 1;
 
@@ -810,7 +810,7 @@ pub const FILE_ACTION_MODIFIED = 0x00000003;
 pub const FILE_ACTION_RENAMED_OLD_NAME = 0x00000004;
 pub const FILE_ACTION_RENAMED_NEW_NAME = 0x00000005;
 
-pub const LPOVERLAPPED_COMPLETION_ROUTINE = ?extern fn (DWORD, DWORD, *OVERLAPPED) void;
+pub const LPOVERLAPPED_COMPLETION_ROUTINE = ?fn (DWORD, DWORD, *OVERLAPPED) callconv(.C) void;
 
 pub const FILE_NOTIFY_CHANGE_CREATION = 64;
 pub const FILE_NOTIFY_CHANGE_SIZE = 8;
@@ -863,7 +863,7 @@ pub const RTL_CRITICAL_SECTION = extern struct {
 pub const CRITICAL_SECTION = RTL_CRITICAL_SECTION;
 pub const INIT_ONCE = RTL_RUN_ONCE;
 pub const INIT_ONCE_STATIC_INIT = RTL_RUN_ONCE_INIT;
-pub const INIT_ONCE_FN = extern fn (InitOnce: *INIT_ONCE, Parameter: ?*c_void, Context: ?*c_void) BOOL;
+pub const INIT_ONCE_FN = fn (InitOnce: *INIT_ONCE, Parameter: ?*c_void, Context: ?*c_void) callconv(.C) BOOL;
 
 pub const RTL_RUN_ONCE = extern struct {
     Ptr: ?*c_void,
@@ -1418,7 +1418,7 @@ pub const RTL_DRIVE_LETTER_CURDIR = extern struct {
     DosPath: UNICODE_STRING,
 };
 
-pub const PPS_POST_PROCESS_INIT_ROUTINE = ?extern fn () void;
+pub const PPS_POST_PROCESS_INIT_ROUTINE = ?fn () callconv(.C) void;
 
 pub const FILE_BOTH_DIR_INFORMATION = extern struct {
     NextEntryOffset: ULONG,
@@ -1438,7 +1438,7 @@ pub const FILE_BOTH_DIR_INFORMATION = extern struct {
 };
 pub const FILE_BOTH_DIRECTORY_INFORMATION = FILE_BOTH_DIR_INFORMATION;
 
-pub const IO_APC_ROUTINE = extern fn (PVOID, *IO_STATUS_BLOCK, ULONG) void;
+pub const IO_APC_ROUTINE = fn (PVOID, *IO_STATUS_BLOCK, ULONG) callconv(.C) void;
 
 pub const CURDIR = extern struct {
     DosPath: UNICODE_STRING,
diff --git a/lib/std/os/windows/user32.zig b/lib/std/os/windows/user32.zig
index bda1fdffb6..3877e19ad8 100644
--- a/lib/std/os/windows/user32.zig
+++ b/lib/std/os/windows/user32.zig
@@ -73,7 +73,6 @@ pub const WM_XBUTTONDBLCLK = 0x020D;
 // WA
 pub const WA_INACTIVE = 0;
 pub const WA_ACTIVE = 0x0006;
-pub const WM_ACTIVATE = 0x0006;
 
 // WS
 pub const WS_OVERLAPPED = 0x00000000;
@@ -147,7 +146,6 @@ pub extern "user32" fn CreateWindowExA(
 
 pub extern "user32" fn RegisterClassExA(*const WNDCLASSEXA) callconv(.Stdcall) c_ushort;
 pub extern "user32" fn DefWindowProcA(HWND, Msg: UINT, WPARAM, LPARAM) callconv(.Stdcall) LRESULT;
-pub extern "user32" fn GetModuleHandleA(lpModuleName: ?LPCSTR) callconv(.Stdcall) HMODULE;
 pub extern "user32" fn ShowWindow(hWnd: ?HWND, nCmdShow: i32) callconv(.Stdcall) bool;
 pub extern "user32" fn UpdateWindow(hWnd: ?HWND) callconv(.Stdcall) bool;
 pub extern "user32" fn GetDC(hWnd: ?HWND) callconv(.Stdcall) ?HDC;
diff --git a/lib/std/os/windows/ws2_32.zig b/lib/std/os/windows/ws2_32.zig
index 31547036ae..d467a60d17 100644
--- a/lib/std/os/windows/ws2_32.zig
+++ b/lib/std/os/windows/ws2_32.zig
@@ -106,7 +106,7 @@ pub const WSAOVERLAPPED = extern struct {
     hEvent: ?WSAEVENT,
 };
 
-pub const WSAOVERLAPPED_COMPLETION_ROUTINE = extern fn (dwError: DWORD, cbTransferred: DWORD, lpOverlapped: *WSAOVERLAPPED, dwFlags: DWORD) void;
+pub const WSAOVERLAPPED_COMPLETION_ROUTINE = fn (dwError: DWORD, cbTransferred: DWORD, lpOverlapped: *WSAOVERLAPPED, dwFlags: DWORD) callconv(.C) void;
 
 pub const ADDRESS_FAMILY = u16;
 
diff --git a/lib/std/pdb.zig b/lib/std/pdb.zig
index 75589b71ff..e4180717e9 100644
--- a/lib/std/pdb.zig
+++ b/lib/std/pdb.zig
@@ -644,7 +644,7 @@ const MsfStream = struct {
         return stream;
     }
 
-    fn readNullTermString(self: *MsfStream, allocator: *mem.Allocator) ![]u8 {
+    pub fn readNullTermString(self: *MsfStream, allocator: *mem.Allocator) ![]u8 {
         var list = ArrayList(u8).init(allocator);
         while (true) {
             const byte = try self.inStream().readByte();
@@ -684,13 +684,13 @@ const MsfStream = struct {
         return buffer.len;
     }
 
-    fn seekBy(self: *MsfStream, len: i64) !void {
+    pub fn seekBy(self: *MsfStream, len: i64) !void {
         self.pos = @intCast(u64, @intCast(i64, self.pos) + len);
         if (self.pos >= self.blocks.len * self.block_size)
             return error.EOF;
     }
 
-    fn seekTo(self: *MsfStream, len: u64) !void {
+    pub fn seekTo(self: *MsfStream, len: u64) !void {
         self.pos = len;
         if (self.pos >= self.blocks.len * self.block_size)
             return error.EOF;
@@ -708,7 +708,7 @@ const MsfStream = struct {
         return block * self.block_size + offset;
     }
 
-    fn inStream(self: *MsfStream) std.io.InStream(*MsfStream, Error, read) {
+    pub fn inStream(self: *MsfStream) std.io.InStream(*MsfStream, Error, read) {
         return .{ .context = self };
     }
 };
diff --git a/lib/std/priority_queue.zig b/lib/std/priority_queue.zig
index e726a07a88..dfd2379da2 100644
--- a/lib/std/priority_queue.zig
+++ b/lib/std/priority_queue.zig
@@ -185,18 +185,18 @@ pub fn PriorityQueue(comptime T: type) type {
             self.len = new_len;
         }
 
-        const Iterator = struct {
+        pub const Iterator = struct {
             queue: *PriorityQueue(T),
             count: usize,
 
-            fn next(it: *Iterator) ?T {
+            pub fn next(it: *Iterator) ?T {
                 if (it.count > it.queue.len - 1) return null;
                 const out = it.count;
                 it.count += 1;
                 return it.queue.items[out];
             }
 
-            fn reset(it: *Iterator) void {
+            pub fn reset(it: *Iterator) void {
                 it.count = 0;
             }
         };
diff --git a/lib/std/special/docs/main.js b/lib/std/special/docs/main.js
index b11e10caa7..7c4cceb31b 100644
--- a/lib/std/special/docs/main.js
+++ b/lib/std/special/docs/main.js
@@ -1498,6 +1498,22 @@
                 }
             ];
 
+            // Links, images and inner links don't use the same marker to wrap their content.
+            const linksFormat = [
+                {
+                    prefix: "[",
+                    regex: /\[([^\]]*)\]\(([^\)]*)\)/,
+                    urlIndex: 2, // Index in the match that contains the link URL
+                    textIndex: 1 // Index in the match that contains the link text
+                },
+                {
+                    prefix: "h",
+                    regex: /http[s]?:\/\/[^\s]+/,
+                    urlIndex: 0,
+                    textIndex: 0
+                }
+            ];
+
             const stack = [];
 
             var innerHTML = "";
@@ -1548,6 +1564,29 @@
                     currentRun += innerText[i];
                     in_code = true;
                 } else {
+                    var foundMatches = false;
+
+                    for (var j = 0; j < linksFormat.length; j++) {
+                        const linkFmt = linksFormat[j];
+
+                        if (linkFmt.prefix == innerText[i]) {
+                            var remaining = innerText.substring(i);
+                            var matches = remaining.match(linkFmt.regex);
+
+                            if (matches) {
+                                flushRun();
+                                innerHTML += ' <a href="' + matches[linkFmt.urlIndex] + '">' + matches[linkFmt.textIndex] + '</a> ';
+                                i += matches[0].length; // Skip the fragment we just consumed
+                                foundMatches = true;
+                                break;
+                            }
+                        }
+                    }
+
+                    if (foundMatches) {
+                        continue;
+                    }
+
                     var any = false;
                     for (var idx = (stack.length > 0 ? -1 : 0); idx < formats.length; idx++) {
                         const fmt = idx >= 0 ? formats[idx] : stack[stack.length - 1];
diff --git a/lib/std/special/test_runner.zig b/lib/std/special/test_runner.zig
index 6dd208e3b4..7403cca9c2 100644
--- a/lib/std/special/test_runner.zig
+++ b/lib/std/special/test_runner.zig
@@ -34,7 +34,7 @@ pub fn main() anyerror!void {
                     std.heap.page_allocator.free(async_frame_buffer);
                     async_frame_buffer = try std.heap.page_allocator.alignedAlloc(u8, std.Target.stack_align, size);
                 }
-                const casted_fn = @ptrCast(async fn () anyerror!void, test_fn.func);
+                const casted_fn = @ptrCast(fn () callconv(.Async) anyerror!void, test_fn.func);
                 break :blk await @asyncCall(async_frame_buffer, {}, casted_fn);
             },
             .blocking => {
diff --git a/lib/std/start.zig b/lib/std/start.zig
index 631bb2e9f8..604c22101c 100644
--- a/lib/std/start.zig
+++ b/lib/std/start.zig
@@ -224,8 +224,7 @@ inline fn initEventLoopAndCallMain() u8 {
     // and we want fewer call frames in stack traces.
     return @call(.{ .modifier = .always_inline }, callMain, .{});
 }
-
-async fn callMainAsync(loop: *std.event.Loop) u8 {
+fn callMainAsync(loop: *std.event.Loop) callconv(.Async) u8 {
     // This prevents the event loop from terminating at least until main() has returned.
     loop.beginOneEvent();
     defer loop.finishOneEvent();
diff --git a/lib/std/thread.zig b/lib/std/thread.zig
index 6d9b4bebe6..d07c41c5b0 100644
--- a/lib/std/thread.zig
+++ b/lib/std/thread.zig
@@ -280,7 +280,7 @@ pub const Thread = struct {
                                 std.debug.dumpStackTrace(trace.*);
                             }
                         };
-                        return 0;
+                        return null;
                     },
                     else => @compileError(bad_startfn_ret),
                 }
diff --git a/lib/std/zig/ast.zig b/lib/std/zig/ast.zig
index 91b9a704c9..b1441d5b25 100644
--- a/lib/std/zig/ast.zig
+++ b/lib/std/zig/ast.zig
@@ -129,6 +129,7 @@ pub const Error = union(enum) {
     ExpectedStatement: ExpectedStatement,
     ExpectedVarDeclOrFn: ExpectedVarDeclOrFn,
     ExpectedVarDecl: ExpectedVarDecl,
+    ExpectedFn: ExpectedFn,
     ExpectedReturnType: ExpectedReturnType,
     ExpectedAggregateKw: ExpectedAggregateKw,
     UnattachedDocComment: UnattachedDocComment,
@@ -165,6 +166,7 @@ pub const Error = union(enum) {
     ExpectedDerefOrUnwrap: ExpectedDerefOrUnwrap,
     ExpectedSuffixOp: ExpectedSuffixOp,
     DeclBetweenFields: DeclBetweenFields,
+    InvalidAnd: InvalidAnd,
 
     pub fn render(self: *const Error, tokens: *Tree.TokenList, stream: var) !void {
         switch (self.*) {
@@ -177,6 +179,7 @@ pub const Error = union(enum) {
             .ExpectedStatement => |*x| return x.render(tokens, stream),
             .ExpectedVarDeclOrFn => |*x| return x.render(tokens, stream),
             .ExpectedVarDecl => |*x| return x.render(tokens, stream),
+            .ExpectedFn => |*x| return x.render(tokens, stream),
             .ExpectedReturnType => |*x| return x.render(tokens, stream),
             .ExpectedAggregateKw => |*x| return x.render(tokens, stream),
             .UnattachedDocComment => |*x| return x.render(tokens, stream),
@@ -213,6 +216,7 @@ pub const Error = union(enum) {
             .ExpectedDerefOrUnwrap => |*x| return x.render(tokens, stream),
             .ExpectedSuffixOp => |*x| return x.render(tokens, stream),
             .DeclBetweenFields => |*x| return x.render(tokens, stream),
+            .InvalidAnd => |*x| return x.render(tokens, stream),
         }
     }
 
@@ -227,6 +231,7 @@ pub const Error = union(enum) {
             .ExpectedStatement => |x| return x.token,
             .ExpectedVarDeclOrFn => |x| return x.token,
             .ExpectedVarDecl => |x| return x.token,
+            .ExpectedFn => |x| return x.token,
             .ExpectedReturnType => |x| return x.token,
             .ExpectedAggregateKw => |x| return x.token,
             .UnattachedDocComment => |x| return x.token,
@@ -263,6 +268,7 @@ pub const Error = union(enum) {
             .ExpectedDerefOrUnwrap => |x| return x.token,
             .ExpectedSuffixOp => |x| return x.token,
             .DeclBetweenFields => |x| return x.token,
+            .InvalidAnd => |x| return x.token,
         }
     }
 
@@ -274,6 +280,7 @@ pub const Error = union(enum) {
     pub const ExpectedStatement = SingleTokenError("Expected statement, found '{}'");
     pub const ExpectedVarDeclOrFn = SingleTokenError("Expected variable declaration or function, found '{}'");
     pub const ExpectedVarDecl = SingleTokenError("Expected variable declaration, found '{}'");
+    pub const ExpectedFn = SingleTokenError("Expected function, found '{}'");
     pub const ExpectedReturnType = SingleTokenError("Expected 'var' or return type expression, found '{}'");
     pub const ExpectedAggregateKw = SingleTokenError("Expected '" ++ Token.Id.Keyword_struct.symbol() ++ "', '" ++ Token.Id.Keyword_union.symbol() ++ "', or '" ++ Token.Id.Keyword_enum.symbol() ++ "', found '{}'");
     pub const ExpectedEqOrSemi = SingleTokenError("Expected '=' or ';', found '{}'");
@@ -308,6 +315,7 @@ pub const Error = union(enum) {
     pub const ExtraVolatileQualifier = SimpleError("Extra volatile qualifier");
     pub const ExtraAllowZeroQualifier = SimpleError("Extra allowzero qualifier");
     pub const DeclBetweenFields = SimpleError("Declarations are not allowed between container fields");
+    pub const InvalidAnd = SimpleError("`&&` is invalid. Note that `and` is boolean AND.");
 
     pub const ExpectedCall = struct {
         node: *Node,
@@ -335,9 +343,6 @@ pub const Error = union(enum) {
         pub fn render(self: *const ExpectedToken, tokens: *Tree.TokenList, stream: var) !void {
             const found_token = tokens.at(self.token);
             switch (found_token.id) {
-                .Invalid_ampersands => {
-                    return stream.print("`&&` is invalid. Note that `and` is boolean AND.", .{});
-                },
                 .Invalid => {
                     return stream.print("expected '{}', found invalid bytes", .{self.expected_id.symbol()});
                 },
@@ -438,7 +443,7 @@ pub const Node = struct {
         ContainerDecl,
         Asm,
         Comptime,
-        Noasync,
+        Nosuspend,
         Block,
 
         // Misc
@@ -569,9 +574,9 @@ pub const Node = struct {
 
                     return true;
                 },
-                .Noasync => {
-                    const noasync_node = @fieldParentPtr(Noasync, "base", n);
-                    return noasync_node.expr.id != .Block;
+                .Nosuspend => {
+                    const nosuspend_node = @fieldParentPtr(Nosuspend, "base", n);
+                    return nosuspend_node.expr.id != .Block;
                 },
                 else => return true,
             }
@@ -875,18 +880,20 @@ pub const Node = struct {
         return_type: ReturnType,
         var_args_token: ?TokenIndex,
         extern_export_inline_token: ?TokenIndex,
-        cc_token: ?TokenIndex,
         body_node: ?*Node,
         lib_name: ?*Node, // populated if this is an extern declaration
         align_expr: ?*Node, // populated if align(A) is present
         section_expr: ?*Node, // populated if linksection(A) is present
         callconv_expr: ?*Node, // populated if callconv(A) is present
+        is_extern_prototype: bool = false, // TODO: Remove once extern fn rewriting is
+        is_async: bool = false, // TODO: remove once async fn rewriting is
 
         pub const ParamList = SegmentedList(*Node, 2);
 
         pub const ReturnType = union(enum) {
             Explicit: *Node,
             InferErrorSet: *Node,
+            Invalid: TokenIndex,
         };
 
         pub fn iterate(self: *FnProto, index: usize) ?*Node {
@@ -915,6 +922,7 @@ pub const Node = struct {
                     if (i < 1) return node;
                     i -= 1;
                 },
+                .Invalid => {},
             }
 
             if (self.body_node) |body_node| {
@@ -929,7 +937,6 @@ pub const Node = struct {
             if (self.visib_token) |visib_token| return visib_token;
             if (self.extern_export_inline_token) |extern_export_inline_token| return extern_export_inline_token;
             assert(self.lib_name == null);
-            if (self.cc_token) |cc_token| return cc_token;
             return self.fn_token;
         }
 
@@ -937,6 +944,7 @@ pub const Node = struct {
             if (self.body_node) |body_node| return body_node.lastToken();
             switch (self.return_type) {
                 .Explicit, .InferErrorSet => |node| return node.lastToken(),
+                .Invalid => |tok| return tok,
             }
         }
     };
@@ -1084,12 +1092,12 @@ pub const Node = struct {
         }
     };
 
-    pub const Noasync = struct {
-        base: Node = Node{ .id = .Noasync },
-        noasync_token: TokenIndex,
+    pub const Nosuspend = struct {
+        base: Node = Node{ .id = .Nosuspend },
+        nosuspend_token: TokenIndex,
         expr: *Node,
 
-        pub fn iterate(self: *Noasync, index: usize) ?*Node {
+        pub fn iterate(self: *Nosuspend, index: usize) ?*Node {
             var i = index;
 
             if (i < 1) return self.expr;
@@ -1098,11 +1106,11 @@ pub const Node = struct {
             return null;
         }
 
-        pub fn firstToken(self: *const Noasync) TokenIndex {
-            return self.noasync_token;
+        pub fn firstToken(self: *const Nosuspend) TokenIndex {
+            return self.nosuspend_token;
         }
 
-        pub fn lastToken(self: *const Noasync) TokenIndex {
+        pub fn lastToken(self: *const Nosuspend) TokenIndex {
             return self.expr.lastToken();
         }
     };
diff --git a/lib/std/zig/cross_target.zig b/lib/std/zig/cross_target.zig
index 8783ddcb6d..1909a07df0 100644
--- a/lib/std/zig/cross_target.zig
+++ b/lib/std/zig/cross_target.zig
@@ -660,7 +660,7 @@ pub const CrossTarget = struct {
         return Target.getObjectFormatSimple(self.getOsTag(), self.getCpuArch());
     }
 
-    fn updateCpuFeatures(self: CrossTarget, set: *Target.Cpu.Feature.Set) void {
+    pub fn updateCpuFeatures(self: CrossTarget, set: *Target.Cpu.Feature.Set) void {
         set.removeFeatureSet(self.cpu_features_sub);
         set.addFeatureSet(self.cpu_features_add);
         set.populateDependencies(self.getCpuArch().allFeaturesList());
diff --git a/lib/std/zig/parse.zig b/lib/std/zig/parse.zig
index fdaf0ec8f1..a269dc616c 100644
--- a/lib/std/zig/parse.zig
+++ b/lib/std/zig/parse.zig
@@ -48,31 +48,24 @@ pub fn parse(allocator: *Allocator, source: []const u8) Allocator.Error!*Tree {
 
     while (it.peek().?.id == .LineComment) _ = it.next();
 
-    tree.root_node = parseRoot(arena, &it, tree) catch |err| blk: {
-        switch (err) {
-            error.ParseError => {
-                assert(tree.errors.len != 0);
-                break :blk undefined;
-            },
-            error.OutOfMemory => {
-                return error.OutOfMemory;
-            },
-        }
-    };
+    tree.root_node = try parseRoot(arena, &it, tree);
 
     return tree;
 }
 
 /// Root <- skip ContainerMembers eof
-fn parseRoot(arena: *Allocator, it: *TokenIterator, tree: *Tree) Error!*Node.Root {
+fn parseRoot(arena: *Allocator, it: *TokenIterator, tree: *Tree) Allocator.Error!*Node.Root {
     const node = try arena.create(Node.Root);
     node.* = .{
         .decls = try parseContainerMembers(arena, it, tree),
-        .eof_token = eatToken(it, .Eof) orelse {
+        .eof_token = eatToken(it, .Eof) orelse blk: {
+            // parseContainerMembers will try to skip as much
+            // invalid tokens as it can so this can only be a '}'
+            const tok = eatToken(it, .RBrace).?;
             try tree.errors.push(.{
-                .ExpectedContainerMembers = .{ .token = it.index },
+                .ExpectedContainerMembers = .{ .token = tok },
             });
-            return error.ParseError;
+            break :blk tok;
         },
     };
     return node;
@@ -108,7 +101,13 @@ fn parseContainerMembers(arena: *Allocator, it: *TokenIterator, tree: *Tree) !No
 
         const doc_comments = try parseDocComment(arena, it, tree);
 
-        if (try parseTestDecl(arena, it, tree)) |node| {
+        if (parseTestDecl(arena, it, tree) catch |err| switch (err) {
+            error.OutOfMemory => return error.OutOfMemory,
+            error.ParseError => {
+                findNextContainerMember(it);
+                continue;
+            },
+        }) |node| {
             if (field_state == .seen) {
                 field_state = .{ .end = node.firstToken() };
             }
@@ -117,7 +116,13 @@ fn parseContainerMembers(arena: *Allocator, it: *TokenIterator, tree: *Tree) !No
             continue;
         }
 
-        if (try parseTopLevelComptime(arena, it, tree)) |node| {
+        if (parseTopLevelComptime(arena, it, tree) catch |err| switch (err) {
+            error.OutOfMemory => return error.OutOfMemory,
+            error.ParseError => {
+                findNextContainerMember(it);
+                continue;
+            },
+        }) |node| {
             if (field_state == .seen) {
                 field_state = .{ .end = node.firstToken() };
             }
@@ -128,7 +133,13 @@ fn parseContainerMembers(arena: *Allocator, it: *TokenIterator, tree: *Tree) !No
 
         const visib_token = eatToken(it, .Keyword_pub);
 
-        if (try parseTopLevelDecl(arena, it, tree)) |node| {
+        if (parseTopLevelDecl(arena, it, tree) catch |err| switch (err) {
+            error.OutOfMemory => return error.OutOfMemory,
+            error.ParseError => {
+                findNextContainerMember(it);
+                continue;
+            },
+        }) |node| {
             if (field_state == .seen) {
                 field_state = .{ .end = visib_token orelse node.firstToken() };
             }
@@ -163,10 +174,18 @@ fn parseContainerMembers(arena: *Allocator, it: *TokenIterator, tree: *Tree) !No
             try tree.errors.push(.{
                 .ExpectedPubItem = .{ .token = it.index },
             });
-            return error.ParseError;
+            // ignore this pub
+            continue;
         }
 
-        if (try parseContainerField(arena, it, tree)) |node| {
+        if (parseContainerField(arena, it, tree) catch |err| switch (err) {
+            error.OutOfMemory => return error.OutOfMemory,
+            error.ParseError => {
+                // attempt to recover
+                findNextContainerMember(it);
+                continue;
+            },
+        }) |node| {
             switch (field_state) {
                 .none => field_state = .seen,
                 .err, .seen => {},
@@ -182,7 +201,21 @@ fn parseContainerMembers(arena: *Allocator, it: *TokenIterator, tree: *Tree) !No
             const field = node.cast(Node.ContainerField).?;
             field.doc_comments = doc_comments;
             try list.push(node);
-            const comma = eatToken(it, .Comma) orelse break;
+            const comma = eatToken(it, .Comma) orelse {
+                // try to continue parsing
+                const index = it.index;
+                findNextContainerMember(it);
+                switch (it.peek().?.id) {
+                    .Eof, .RBrace => break,
+                    else => {
+                        // add error and continue
+                        try tree.errors.push(.{
+                            .ExpectedToken = .{ .token = index, .expected_id = .Comma },
+                        });
+                        continue;
+                    },
+                }
+            };
             if (try parseAppendedDocComment(arena, it, tree, comma)) |appended_comment|
                 field.doc_comments = appended_comment;
             continue;
@@ -194,12 +227,102 @@ fn parseContainerMembers(arena: *Allocator, it: *TokenIterator, tree: *Tree) !No
                 .UnattachedDocComment = .{ .token = doc_comments.?.firstToken() },
             });
         }
-        break;
+
+        switch (it.peek().?.id) {
+            .Eof, .RBrace => break,
+            else => {
+                // this was likely not supposed to end yet,
+                // try to find the next declaration
+                const index = it.index;
+                findNextContainerMember(it);
+                try tree.errors.push(.{
+                    .ExpectedContainerMembers = .{ .token = index },
+                });
+            },
+        }
     }
 
     return list;
 }
 
+/// Attempts to find next container member by searching for certain tokens
+fn findNextContainerMember(it: *TokenIterator) void {
+    var level: u32 = 0;
+    while (true) {
+        const tok = nextToken(it);
+        switch (tok.ptr.id) {
+            // any of these can start a new top level declaration
+            .Keyword_test,
+            .Keyword_comptime,
+            .Keyword_pub,
+            .Keyword_export,
+            .Keyword_extern,
+            .Keyword_inline,
+            .Keyword_noinline,
+            .Keyword_usingnamespace,
+            .Keyword_threadlocal,
+            .Keyword_const,
+            .Keyword_var,
+            .Keyword_fn,
+            .Identifier,
+            => {
+                if (level == 0) {
+                    putBackToken(it, tok.index);
+                    return;
+                }
+            },
+            .Comma, .Semicolon => {
+                // this decl was likely meant to end here
+                if (level == 0) {
+                    return;
+                }
+            },
+            .LParen, .LBracket, .LBrace => level += 1,
+            .RParen, .RBracket, .RBrace => {
+                if (level == 0) {
+                    // end of container, exit
+                    putBackToken(it, tok.index);
+                    return;
+                }
+                level -= 1;
+            },
+            .Eof => {
+                putBackToken(it, tok.index);
+                return;
+            },
+            else => {},
+        }
+    }
+}
+
+/// Attempts to find the next statement by searching for a semicolon
+fn findNextStmt(it: *TokenIterator) void {
+    var level: u32 = 0;
+    while (true) {
+        const tok = nextToken(it);
+        switch (tok.ptr.id) {
+            .LBrace => level += 1,
+            .RBrace => {
+                if (level == 0) {
+                    putBackToken(it, tok.index);
+                    return;
+                }
+                level -= 1;
+            },
+            .Semicolon => {
+                if (level == 0) {
+                    return;
+                }
+            },
+            .Eof => {
+                putBackToken(it, tok.index);
+                return;
+            },
+            else => {},
+        }
+    }
+}
+
 /// Eat a multiline container doc comment
 fn parseContainerDocComments(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
     var lines = Node.DocComment.LineList.init(arena);
@@ -279,22 +402,30 @@ fn parseTopLevelDecl(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
         fn_node.*.extern_export_inline_token = extern_export_inline_token;
         fn_node.*.lib_name = lib_name;
         if (eatToken(it, .Semicolon)) |_| return node;
-        if (try parseBlock(arena, it, tree)) |body_node| {
+        if (parseBlock(arena, it, tree) catch |err| switch (err) {
+            error.OutOfMemory => return error.OutOfMemory,
+            // since parseBlock only return error.ParseError on
+            // a missing '}' we can assume this function was
+            // supposed to end here.
+            error.ParseError => return node,
+        }) |body_node| {
             fn_node.body_node = body_node;
             return node;
         }
         try tree.errors.push(.{
             .ExpectedSemiOrLBrace = .{ .token = it.index },
         });
-        return null;
+        return error.ParseError;
     }
 
     if (extern_export_inline_token) |token| {
         if (tree.tokens.at(token).id == .Keyword_inline or
             tree.tokens.at(token).id == .Keyword_noinline)
         {
-            putBackToken(it, token);
-            return null;
+            try tree.errors.push(.{
+                .ExpectedFn = .{ .token = it.index },
+            });
+            return error.ParseError;
         }
     }
 
@@ -313,42 +444,40 @@ fn parseTopLevelDecl(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
         try tree.errors.push(.{
             .ExpectedVarDecl = .{ .token = it.index },
         });
+        // ignore this and try again;
         return error.ParseError;
     }
 
     if (extern_export_inline_token) |token| {
-        if (lib_name) |string_literal_node|
-            putBackToken(it, string_literal_node.cast(Node.StringLiteral).?.token);
-        putBackToken(it, token);
-        return null;
+        try tree.errors.push(.{
+            .ExpectedVarDeclOrFn = .{ .token = it.index },
+        });
+        // ignore this and try again;
+        return error.ParseError;
     }
 
-    const use_node = (try parseUse(arena, it, tree)) orelse return null;
-    const expr_node = try expectNode(arena, it, tree, parseExpr, .{
-        .ExpectedExpr = .{ .token = it.index },
-    });
-    const semicolon_token = try expectToken(it, tree, .Semicolon);
-    const use_node_raw = use_node.cast(Node.Use).?;
-    use_node_raw.*.expr = expr_node;
-    use_node_raw.*.semicolon_token = semicolon_token;
-
-    return use_node;
+    return try parseUse(arena, it, tree);
 }
 
-/// FnProto <- FnCC? KEYWORD_fn IDENTIFIER? LPAREN ParamDeclList RPAREN ByteAlign? LinkSection? EXCLAMATIONMARK? (KEYWORD_var / TypeExpr)
+/// FnProto <- KEYWORD_fn IDENTIFIER? LPAREN ParamDeclList RPAREN ByteAlign? LinkSection? EXCLAMATIONMARK? (KEYWORD_var / TypeExpr)
 fn parseFnProto(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
-    const cc = parseFnCC(arena, it, tree);
-    const fn_token = eatToken(it, .Keyword_fn) orelse {
-        if (cc) |fnCC| {
-            if (fnCC == .Extern) {
-                putBackToken(it, fnCC.Extern); // 'extern' is also used in ContainerDecl
-            } else {
-                try tree.errors.push(.{
-                    .ExpectedToken = .{ .token = it.index, .expected_id = .Keyword_fn },
-                });
-                return error.ParseError;
-            }
+    // TODO: Remove once extern/async fn rewriting is
+    var is_async = false;
+    var is_extern = false;
+    const cc_token: ?usize = blk: {
+        if (eatToken(it, .Keyword_extern)) |token| {
+            is_extern = true;
+            break :blk token;
         }
+        if (eatToken(it, .Keyword_async)) |token| {
+            is_async = true;
+            break :blk token;
+        }
+        break :blk null;
+    };
+    const fn_token = eatToken(it, .Keyword_fn) orelse {
+        if (cc_token) |token|
+            putBackToken(it, token);
         return null;
     };
     const name_token = eatToken(it, .Identifier);
@@ -361,18 +490,23 @@ fn parseFnProto(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
     const exclamation_token = eatToken(it, .Bang);
 
     const return_type_expr = (try parseVarType(arena, it, tree)) orelse
-        try expectNode(arena, it, tree, parseTypeExpr, .{
-        .ExpectedReturnType = .{ .token = it.index },
-    });
+        (try parseTypeExpr(arena, it, tree)) orelse blk: {
+        try tree.errors.push(.{
+            .ExpectedReturnType = .{ .token = it.index },
+        });
+        // most likely the user forgot to specify the return type.
+        // Mark return type as invalid and try to continue.
+        break :blk null;
+    };
 
-    const return_type: Node.FnProto.ReturnType = if (exclamation_token != null)
-        .{
-            .InferErrorSet = return_type_expr,
-        }
+    // TODO https://github.com/ziglang/zig/issues/3750
+    const R = Node.FnProto.ReturnType;
+    const return_type = if (return_type_expr == null)
+        R{ .Invalid = rparen }
+    else if (exclamation_token != null)
+        R{ .InferErrorSet = return_type_expr.? }
     else
-        .{
-            .Explicit = return_type_expr,
-        };
+        R{ .Explicit = return_type_expr.? };
 
     const var_args_token = if (params.len > 0)
         params.at(params.len - 1).*.cast(Node.ParamDecl).?.var_args_token
@@ -389,21 +523,15 @@ fn parseFnProto(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
         .return_type = return_type,
         .var_args_token = var_args_token,
         .extern_export_inline_token = null,
-        .cc_token = null,
         .body_node = null,
         .lib_name = null,
         .align_expr = align_expr,
         .section_expr = section_expr,
         .callconv_expr = callconv_expr,
+        .is_extern_prototype = is_extern,
+        .is_async = is_async,
     };
 
-    if (cc) |kind| {
-        switch (kind) {
-            .CC => |token| fn_proto_node.cc_token = token,
-            .Extern => |token| fn_proto_node.extern_export_inline_token = token,
-        }
-    }
-
     return &fn_proto_node.base;
 }
 
@@ -495,7 +623,7 @@ fn parseContainerField(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*No
 /// Statement
 ///     <- KEYWORD_comptime? VarDecl
 ///      / KEYWORD_comptime BlockExprStatement
-///      / KEYWORD_noasync BlockExprStatement
+///      / KEYWORD_nosuspend BlockExprStatement
 ///      / KEYWORD_suspend (SEMICOLON / BlockExprStatement)
 ///      / KEYWORD_defer BlockExprStatement
 ///      / KEYWORD_errdefer Payload? BlockExprStatement
@@ -527,14 +655,14 @@ fn parseStatement(arena: *Allocator, it: *TokenIterator, tree: *Tree) Error!?*No
         return &node.base;
     }
 
-    if (eatToken(it, .Keyword_noasync)) |noasync_token| {
+    if (eatToken(it, .Keyword_nosuspend)) |nosuspend_token| {
         const block_expr = try expectNode(arena, it, tree, parseBlockExprStatement, .{
             .ExpectedBlockOrAssignment = .{ .token = it.index },
         });
 
-        const node = try arena.create(Node.Noasync);
+        const node = try arena.create(Node.Nosuspend);
         node.* = .{
-            .noasync_token = noasync_token,
+            .nosuspend_token = nosuspend_token,
             .expr = block_expr,
         };
         return &node.base;
@@ -579,7 +707,12 @@ fn parseStatement(arena: *Allocator, it: *TokenIterator, tree: *Tree) Error!?*No
     if (try parseLabeledStatement(arena, it, tree)) |node| return node;
     if (try parseSwitchExpr(arena, it, tree)) |node| return node;
     if (try parseAssignExpr(arena, it, tree)) |node| {
-        _ = try expectToken(it, tree, .Semicolon);
+        _ = eatToken(it, .Semicolon) orelse {
+            try tree.errors.push(.{
+                .ExpectedToken = .{ .token = it.index, .expected_id = .Semicolon },
+            });
+            // pretend we saw a semicolon and continue parsing
+        };
         return node;
     }
 
@@ -688,8 +821,13 @@ fn parseLoopStatement(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Nod
         node.cast(Node.While).?.inline_token = inline_token;
         return node;
     }
+    if (inline_token == null) return null;
 
-    return null;
+    // If we've seen "inline", there should have been a "for" or "while"
+    try tree.errors.push(.{
+        .ExpectedInlinable = .{ .token = it.index },
+    });
+    return error.ParseError;
 }
 
 /// ForStatement
@@ -818,7 +956,12 @@ fn parseWhileStatement(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*No
 fn parseBlockExprStatement(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
     if (try parseBlockExpr(arena, it, tree)) |node| return node;
     if (try parseAssignExpr(arena, it, tree)) |node| {
-        _ = try expectToken(it, tree, .Semicolon);
+        _ = eatToken(it, .Semicolon) orelse {
+            try tree.errors.push(.{
+                .ExpectedToken = .{ .token = it.index, .expected_id = .Semicolon },
+            });
+            // pretend we saw a semicolon and continue parsing
+        };
         return node;
     }
     return null;
@@ -908,7 +1051,7 @@ fn parsePrefixExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
 ///      / IfExpr
 ///      / KEYWORD_break BreakLabel? Expr?
 ///      / KEYWORD_comptime Expr
-///      / KEYWORD_noasync Expr
+///      / KEYWORD_nosuspend Expr
 ///      / KEYWORD_continue BreakLabel?
 ///      / KEYWORD_resume Expr
 ///      / KEYWORD_return Expr?
@@ -925,7 +1068,7 @@ fn parsePrimaryExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
         const node = try arena.create(Node.ControlFlowExpression);
         node.* = .{
             .ltoken = token,
-            .kind = Node.ControlFlowExpression.Kind{ .Break = label },
+            .kind = .{ .Break = label },
             .rhs = expr_node,
         };
         return &node.base;
@@ -944,13 +1087,13 @@ fn parsePrimaryExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
         return &node.base;
     }
 
-    if (eatToken(it, .Keyword_noasync)) |token| {
+    if (eatToken(it, .Keyword_nosuspend)) |token| {
         const expr_node = try expectNode(arena, it, tree, parseExpr, .{
             .ExpectedExpr = .{ .token = it.index },
         });
-        const node = try arena.create(Node.Noasync);
+        const node = try arena.create(Node.Nosuspend);
         node.* = .{
-            .noasync_token = token,
+            .nosuspend_token = token,
             .expr = expr_node,
         };
         return &node.base;
@@ -961,7 +1104,7 @@ fn parsePrimaryExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
         const node = try arena.create(Node.ControlFlowExpression);
         node.* = .{
             .ltoken = token,
-            .kind = Node.ControlFlowExpression.Kind{ .Continue = label },
+            .kind = .{ .Continue = label },
             .rhs = null,
         };
         return &node.base;
@@ -985,7 +1128,7 @@ fn parsePrimaryExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
         const node = try arena.create(Node.ControlFlowExpression);
         node.* = .{
             .ltoken = token,
-            .kind = Node.ControlFlowExpression.Kind.Return,
+            .kind = .Return,
             .rhs = expr_node,
         };
         return &node.base;
@@ -1023,7 +1166,14 @@ fn parseBlock(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
 
     var statements = Node.Block.StatementList.init(arena);
     while (true) {
-        const statement = (try parseStatement(arena, it, tree)) orelse break;
+        const statement = (parseStatement(arena, it, tree) catch |err| switch (err) {
+            error.OutOfMemory => return error.OutOfMemory,
+            error.ParseError => {
+                // try to skip to the next statement
+                findNextStmt(it);
+                continue;
+            },
+        }) orelse break;
         try statements.push(statement);
     }
 
@@ -1197,6 +1347,7 @@ fn parseSuffixExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
     if (maybe_async) |async_token| {
         const token_fn = eatToken(it, .Keyword_fn);
         if (token_fn != null) {
+            // TODO: remove this hack when async fn rewriting is
             // HACK: If we see the keyword `fn`, then we assume that
             //       we are parsing an async fn proto, and not a call.
             //       We therefore put back all tokens consumed by the async
@@ -1205,7 +1356,6 @@ fn parseSuffixExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
             putBackToken(it, async_token);
             return parsePrimaryTypeExpr(arena, it, tree);
         }
-        // TODO: Implement hack for parsing `async fn ...` in ast_parse_suffix_expr
         var res = try expectNode(arena, it, tree, parsePrimaryTypeExpr, .{
             .ExpectedPrimaryTypeExpr = .{ .token = it.index },
         });
@@ -1223,7 +1373,8 @@ fn parseSuffixExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
             try tree.errors.push(.{
                 .ExpectedParamList = .{ .token = it.index },
             });
-            return null;
+            // ignore this, continue parsing
+            return res;
         };
         const node = try arena.create(Node.SuffixOp);
         node.* = .{
@@ -1288,7 +1439,6 @@ fn parseSuffixExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
 ///      / IfTypeExpr
 ///      / INTEGER
 ///      / KEYWORD_comptime TypeExpr
-///      / KEYWORD_noasync TypeExpr
 ///      / KEYWORD_error DOT IDENTIFIER
 ///      / KEYWORD_false
 ///      / KEYWORD_null
@@ -1327,15 +1477,6 @@ fn parsePrimaryTypeExpr(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*N
         };
         return &node.base;
     }
-    if (eatToken(it, .Keyword_noasync)) |token| {
-        const expr = (try parseTypeExpr(arena, it, tree)) orelse return null;
-        const node = try arena.create(Node.Noasync);
-        node.* = .{
-            .noasync_token = token,
-            .expr = expr,
-        };
-        return &node.base;
-    }
     if (eatToken(it, .Keyword_error)) |token| {
         const period = try expectToken(it, tree, .Period);
         const identifier = try expectNode(arena, it, tree, parseIdentifier, .{
@@ -1778,24 +1919,6 @@ fn parseCallconv(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
     return expr_node;
 }
 
-/// FnCC
-///     <- KEYWORD_nakedcc
-///      / KEYWORD_stdcallcc
-///      / KEYWORD_extern
-///      / KEYWORD_async
-fn parseFnCC(arena: *Allocator, it: *TokenIterator, tree: *Tree) ?FnCC {
-    if (eatToken(it, .Keyword_nakedcc)) |token| return FnCC{ .CC = token };
-    if (eatToken(it, .Keyword_stdcallcc)) |token| return FnCC{ .CC = token };
-    if (eatToken(it, .Keyword_extern)) |token| return FnCC{ .Extern = token };
-    if (eatToken(it, .Keyword_async)) |token| return FnCC{ .CC = token };
-    return null;
-}
-
-const FnCC = union(enum) {
-    CC: TokenIndex,
-    Extern: TokenIndex,
-};
-
 /// ParamDecl <- (KEYWORD_noalias / KEYWORD_comptime)? (IDENTIFIER COLON)? ParamType
 fn parseParamDecl(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
     const doc_comments = try parseDocComment(arena, it, tree);
@@ -2290,7 +2413,7 @@ fn parsePrefixTypeOp(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
         const node = try arena.create(Node.AnyFrameType);
         node.* = .{
             .anyframe_token = token,
-            .result = Node.AnyFrameType.Result{
+            .result = .{
                 .arrow_token = arrow,
                 .return_type = undefined, // set by caller
             },
@@ -2331,6 +2454,13 @@ fn parsePrefixTypeOp(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
                 } else null;
                 _ = try expectToken(it, tree, .RParen);
 
+                if (ptr_info.align_info != null) {
+                    try tree.errors.push(.{
+                        .ExtraAlignQualifier = .{ .token = it.index - 1 },
+                    });
+                    continue;
+                }
+
                 ptr_info.align_info = Node.PrefixOp.PtrInfo.Align{
                     .node = expr_node,
                     .bit_range = bit_range,
@@ -2339,14 +2469,32 @@ fn parsePrefixTypeOp(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
                 continue;
             }
             if (eatToken(it, .Keyword_const)) |const_token| {
+                if (ptr_info.const_token != null) {
+                    try tree.errors.push(.{
+                        .ExtraConstQualifier = .{ .token = it.index - 1 },
+                    });
+                    continue;
+                }
                 ptr_info.const_token = const_token;
                 continue;
             }
             if (eatToken(it, .Keyword_volatile)) |volatile_token| {
+                if (ptr_info.volatile_token != null) {
+                    try tree.errors.push(.{
+                        .ExtraVolatileQualifier = .{ .token = it.index - 1 },
+                    });
+                    continue;
+                }
                 ptr_info.volatile_token = volatile_token;
                 continue;
             }
             if (eatToken(it, .Keyword_allowzero)) |allowzero_token| {
+                if (ptr_info.allowzero_token != null) {
+                    try tree.errors.push(.{
+                        .ExtraAllowZeroQualifier = .{ .token = it.index - 1 },
+                    });
+                    continue;
+                }
                 ptr_info.allowzero_token = allowzero_token;
                 continue;
             }
@@ -2365,9 +2513,9 @@ fn parsePrefixTypeOp(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
                     if (try parseByteAlign(arena, it, tree)) |align_expr| {
                         if (slice_type.align_info != null) {
                             try tree.errors.push(.{
-                                .ExtraAlignQualifier = .{ .token = it.index },
+                                .ExtraAlignQualifier = .{ .token = it.index - 1 },
                             });
-                            return error.ParseError;
+                            continue;
                         }
                         slice_type.align_info = Node.PrefixOp.PtrInfo.Align{
                             .node = align_expr,
@@ -2378,9 +2526,9 @@ fn parsePrefixTypeOp(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
                     if (eatToken(it, .Keyword_const)) |const_token| {
                         if (slice_type.const_token != null) {
                             try tree.errors.push(.{
-                                .ExtraConstQualifier = .{ .token = it.index },
+                                .ExtraConstQualifier = .{ .token = it.index - 1 },
                             });
-                            return error.ParseError;
+                            continue;
                         }
                         slice_type.const_token = const_token;
                         continue;
@@ -2388,9 +2536,9 @@ fn parsePrefixTypeOp(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
                     if (eatToken(it, .Keyword_volatile)) |volatile_token| {
                         if (slice_type.volatile_token != null) {
                             try tree.errors.push(.{
-                                .ExtraVolatileQualifier = .{ .token = it.index },
+                                .ExtraVolatileQualifier = .{ .token = it.index - 1 },
                             });
-                            return error.ParseError;
+                            continue;
                         }
                         slice_type.volatile_token = volatile_token;
                         continue;
@@ -2398,9 +2546,9 @@ fn parsePrefixTypeOp(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
                     if (eatToken(it, .Keyword_allowzero)) |allowzero_token| {
                         if (slice_type.allowzero_token != null) {
                             try tree.errors.push(.{
-                                .ExtraAllowZeroQualifier = .{ .token = it.index },
+                                .ExtraAllowZeroQualifier = .{ .token = it.index - 1 },
                             });
-                            return error.ParseError;
+                            continue;
                         }
                         slice_type.allowzero_token = allowzero_token;
                         continue;
@@ -2749,7 +2897,19 @@ fn ListParseFn(comptime L: type, comptime nodeParseFn: var) ParseFn(L) {
             var list = L.init(arena);
             while (try nodeParseFn(arena, it, tree)) |node| {
                 try list.push(node);
-                if (eatToken(it, .Comma) == null) break;
+
+                switch (it.peek().?.id) {
+                    .Comma => _ = nextToken(it),
+                    // all possible delimiters
+                    .Colon, .RParen, .RBrace, .RBracket => break,
+                    else => {
+                        // this is likely just a missing comma,
+                        // continue parsing this list and give an error
+                        try tree.errors.push(.{
+                            .ExpectedToken = .{ .token = it.index, .expected_id = .Comma },
+                        });
+                    },
+                }
             }
             return list;
         }
@@ -2759,7 +2919,17 @@ fn ListParseFn(comptime L: type, comptime nodeParseFn: var) ParseFn(L) {
 fn SimpleBinOpParseFn(comptime token: Token.Id, comptime op: Node.InfixOp.Op) NodeParseFn {
     return struct {
         pub fn parse(arena: *Allocator, it: *TokenIterator, tree: *Tree) Error!?*Node {
-            const op_token = eatToken(it, token) orelse return null;
+            const op_token = if (token == .Keyword_and) switch (it.peek().?.id) {
+                .Keyword_and => nextToken(it).index,
+                .Invalid_ampersands => blk: {
+                    try tree.errors.push(.{
+                        .InvalidAnd = .{ .token = it.index },
+                    });
+                    break :blk nextToken(it).index;
+                },
+                else => return null,
+            } else eatToken(it, token) orelse return null;
+
             const node = try arena.create(Node.InfixOp);
             node.* = .{
                 .op_token = op_token,
@@ -2780,7 +2950,13 @@ fn parseBuiltinCall(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node
         try tree.errors.push(.{
             .ExpectedParamList = .{ .token = it.index },
         });
-        return error.ParseError;
+
+        // lets pretend this was an identifier so we can continue parsing
+        const node = try arena.create(Node.Identifier);
+        node.* = .{
+            .token = token,
+        };
+        return &node.base;
     };
     const node = try arena.create(Node.BuiltinCall);
     node.* = .{
@@ -2896,8 +3072,10 @@ fn parseUse(arena: *Allocator, it: *TokenIterator, tree: *Tree) !?*Node {
         .doc_comments = null,
         .visib_token = null,
         .use_token = token,
-        .expr = undefined, // set by caller
-        .semicolon_token = undefined, // set by caller
+        .expr = try expectNode(arena, it, tree, parseExpr, .{
+            .ExpectedExpr = .{ .token = it.index },
+        }),
+        .semicolon_token = try expectToken(it, tree, .Semicolon),
     };
     return &node.base;
 }
@@ -3077,6 +3255,8 @@ fn expectToken(it: *TokenIterator, tree: *Tree, id: Token.Id) Error!TokenIndex {
         try tree.errors.push(.{
             .ExpectedToken = .{ .token = token.index, .expected_id = id },
         });
+        // go back so that we can recover properly
+        putBackToken(it, token.index);
         return error.ParseError;
     }
     return token.index;
diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
index 7fca72ac70..6adc44a5b7 100644
--- a/lib/std/zig/parser_test.zig
+++ b/lib/std/zig/parser_test.zig
@@ -1,3 +1,153 @@
+test "recovery: top level" {
+    try testError(
+        \\test "" {inline}
+        \\test "" {inline}
+    , &[_]Error{
+        .ExpectedInlinable,
+        .ExpectedInlinable,
+    });
+}
+
+test "recovery: block statements" {
+    try testError(
+        \\test "" {
+        \\    foo + +;
+        \\    inline;
+        \\}
+    , &[_]Error{
+        .InvalidToken,
+        .ExpectedInlinable,
+    });
+}
+
+test "recovery: missing comma" {
+    try testError(
+        \\test "" {
+        \\    switch (foo) {
+        \\        2 => {}
+        \\        3 => {}
+        \\        else => {
+        \\            foo && bar +;
+        \\        }
+        \\    }
+        \\}
+    , &[_]Error{
+        .ExpectedToken,
+        .ExpectedToken,
+        .InvalidAnd,
+        .InvalidToken,
+    });
+}
+
+test "recovery: extra qualifier" {
+    try testError(
+        \\const a: *const const u8;
+        \\test ""
+    , &[_]Error{
+        .ExtraConstQualifier,
+        .ExpectedLBrace,
+    });
+}
+
+test "recovery: missing return type" {
+    try testError(
+        \\fn foo() {
+        \\    a && b;
+        \\}
+        \\test ""
+    , &[_]Error{
+        .ExpectedReturnType,
+        .InvalidAnd,
+        .ExpectedLBrace,
+    });
+}
+
+test "recovery: continue after invalid decl" {
+    try testError(
+        \\fn foo {
+        \\    inline;
+        \\}
+        \\pub test "" {
+        \\    async a && b;
+        \\}
+    , &[_]Error{
+        .ExpectedToken,
+        .ExpectedPubItem,
+        .ExpectedParamList,
+        .InvalidAnd,
+    });
+    try testError(
+        \\threadlocal test "" {
+        \\    @a && b;
+        \\}
+    , &[_]Error{
+        .ExpectedVarDecl,
+        .ExpectedParamList,
+        .InvalidAnd,
+    });
+}
+
+test "recovery: invalid extern/inline" {
+    try testError(
+        \\inline test "" { a && b; }
+    , &[_]Error{
+        .ExpectedFn,
+        .InvalidAnd,
+    });
+    try testError(
+        \\extern "" test "" { a && b; }
+    , &[_]Error{
+        .ExpectedVarDeclOrFn,
+        .InvalidAnd,
+    });
+}
+
+test "recovery: missing semicolon" {
+    try testError(
+        \\test "" {
+        \\    comptime a && b
+        \\    c && d
+        \\    @foo
+        \\}
+    , &[_]Error{
+        .InvalidAnd,
+        .ExpectedToken,
+        .InvalidAnd,
+        .ExpectedToken,
+        .ExpectedParamList,
+        .ExpectedToken,
+    });
+}
+
+test "recovery: invalid container members" {
+    try testError(
+        \\usingnamespace;
+        \\foo+
+        \\bar@,
+        \\while (a == 2) { test "" {}}
+        \\test "" {
+        \\    a && b
+        \\}
+    , &[_]Error{
+        .ExpectedExpr,
+        .ExpectedToken,
+        .ExpectedToken,
+        .ExpectedContainerMembers,
+        .InvalidAnd,
+        .ExpectedToken,
+    });
+}
+
+test "recovery: invalid parameter" {
+    try testError(
+        \\fn main() void {
+        \\    a(comptime T: type)
+        \\}
+    , &[_]Error{
+        .ExpectedToken,
+    });
+}
+
 test "zig fmt: top-level fields" {
     try testCanonical(
         \\a: did_you_know,
@@ -19,7 +169,9 @@ test "zig fmt: decl between fields" {
         \\    const baz1 = 2;
         \\    b: usize,
         \\};
-    );
+    , &[_]Error{
+        .DeclBetweenFields,
+    });
 }
 
 test "zig fmt: errdefer with payload" {
@@ -35,10 +187,10 @@ test "zig fmt: errdefer with payload" {
     );
 }
 
-test "zig fmt: noasync block" {
+test "zig fmt: nosuspend block" {
     try testCanonical(
         \\pub fn main() anyerror!void {
-        \\    noasync {
+        \\    nosuspend {
         \\        var foo: Foo = .{ .bar = 42 };
         \\    }
         \\}
@@ -46,10 +198,10 @@ test "zig fmt: noasync block" {
     );
 }
 
-test "zig fmt: noasync await" {
+test "zig fmt: nosuspend await" {
     try testCanonical(
         \\fn foo() void {
-        \\    x = noasync await y;
+        \\    x = nosuspend await y;
         \\}
         \\
     );
@@ -123,22 +275,6 @@ test "zig fmt: trailing comma in fn parameter list" {
     );
 }
 
-// TODO: Remove nakedcc/stdcallcc once zig 0.6.0 is released. See https://github.com/ziglang/zig/pull/3977
-test "zig fmt: convert extern/nakedcc/stdcallcc into callconv(...)" {
-    try testTransform(
-        \\nakedcc fn foo1() void {}
-        \\stdcallcc fn foo2() void {}
-        \\extern fn foo3() void {}
-        \\extern "mylib" fn foo4() void {}
-    ,
-        \\fn foo1() callconv(.Naked) void {}
-        \\fn foo2() callconv(.Stdcall) void {}
-        \\fn foo3() callconv(.C) void {}
-        \\fn foo4() callconv(.C) void {}
-        \\
-    );
-}
-
 test "zig fmt: comptime struct field" {
     try testCanonical(
         \\const Foo = struct {
@@ -252,10 +388,10 @@ test "zig fmt: anon list literal syntax" {
 test "zig fmt: async function" {
     try testCanonical(
         \\pub const Server = struct {
-        \\    handleRequestFn: async fn (*Server, *const std.net.Address, File) void,
+        \\    handleRequestFn: fn (*Server, *const std.net.Address, File) callconv(.Async) void,
         \\};
         \\test "hi" {
-        \\    var ptr = @ptrCast(async fn (i32) void, other);
+        \\    var ptr = @ptrCast(fn (i32) callconv(.Async) void, other);
         \\}
         \\
     );
@@ -451,15 +587,6 @@ test "zig fmt: aligned struct field" {
     );
 }
 
-test "zig fmt: preserve space between async fn definitions" {
-    try testCanonical(
-        \\async fn a() void {}
-        \\
-        \\async fn b() void {}
-        \\
-    );
-}
-
 test "zig fmt: comment to disable/enable zig fmt first" {
     try testCanonical(
         \\// Test trailing comma syntax
@@ -1515,7 +1642,7 @@ test "zig fmt: line comments in struct initializer" {
 
 test "zig fmt: first line comment in struct initializer" {
     try testCanonical(
-        \\pub async fn acquire(self: *Self) HeldLock {
+        \\pub fn acquire(self: *Self) HeldLock {
         \\    return HeldLock{
         \\        // guaranteed allocation elision
         \\        .held = self.lock.acquire(),
@@ -2477,8 +2604,7 @@ test "zig fmt: fn type" {
         \\}
         \\
         \\const a: fn (u8) u8 = undefined;
-        \\const b: extern fn (u8) u8 = undefined;
-        \\const c: fn (u8) callconv(.Naked) u8 = undefined;
+        \\const b: fn (u8) callconv(.Naked) u8 = undefined;
         \\const ap: fn (u8) u8 = a;
         \\
     );
@@ -2500,7 +2626,7 @@ test "zig fmt: inline asm" {
 
 test "zig fmt: async functions" {
     try testCanonical(
-        \\async fn simpleAsyncFn() void {
+        \\fn simpleAsyncFn() void {
         \\    const a = async a.b();
         \\    x += 1;
         \\    suspend;
@@ -2519,9 +2645,9 @@ test "zig fmt: async functions" {
     );
 }
 
-test "zig fmt: noasync" {
+test "zig fmt: nosuspend" {
     try testCanonical(
-        \\const a = noasync foo();
+        \\const a = nosuspend foo();
         \\
     );
 }
@@ -2854,7 +2980,10 @@ test "zig fmt: extern without container keyword returns error" {
     try testError(
         \\const container = extern {};
         \\
-    );
+    , &[_]Error{
+        .ExpectedExpr,
+        .ExpectedVarDeclOrFn,
+    });
 }
 
 test "zig fmt: integer literals with underscore separators" {
@@ -2926,6 +3055,40 @@ test "zig fmt: hexadeciaml float literals with underscore separators" {
     );
 }
 
+test "zig fmt: noasync to nosuspend" {
+    // TODO: remove this
+    try testTransform(
+        \\pub fn main() void {
+        \\    noasync call();
+        \\}
+    ,
+        \\pub fn main() void {
+        \\    nosuspend call();
+        \\}
+        \\
+    );
+}
+
+test "zig fmt: convert async fn into callconv(.Async)" {
+    try testTransform(
+        \\async fn foo() void {}
+    ,
+        \\fn foo() callconv(.Async) void {}
+        \\
+    );
+}
+
+test "zig fmt: convert extern fn proto into callconv(.C)" {
+    try testTransform(
+        \\extern fn foo0() void {}
+        \\const foo1 = extern fn () void;
+    ,
+        \\extern fn foo0() void {}
+        \\const foo1 = fn () callconv(.C) void;
+        \\
+    );
+}
+
 const std = @import("std");
 const mem = std.mem;
 const warn = std.debug.warn;
@@ -2972,7 +3135,6 @@ fn testParse(source: []const u8, allocator: *mem.Allocator, anything_changed: *b
     anything_changed.* = try std.zig.render(allocator, buffer.outStream(), tree);
     return buffer.toOwnedSlice();
 }
-
 fn testTransform(source: []const u8, expected_source: []const u8) !void {
     const needed_alloc_count = x: {
         // Try it once with unlimited memory, make sure it works
@@ -3020,14 +3182,20 @@ fn testTransform(source: []const u8, expected_source: []const u8) !void {
         }
     }
 }
-
 fn testCanonical(source: []const u8) !void {
     return testTransform(source, source);
 }
 
-fn testError(source: []const u8) !void {
+const Error = @TagType(std.zig.ast.Error);
+
+fn testError(source: []const u8, expected_errors: []const Error) !void {
     const tree = try std.zig.parse(std.testing.allocator, source);
     defer tree.deinit();
 
-    std.testing.expect(tree.errors.len != 0);
+    std.testing.expect(tree.errors.len == expected_errors.len);
+    for (expected_errors) |expected, i| {
+        const err = tree.errors.at(i);
+
+        std.testing.expect(expected == err.*);
+    }
 }
diff --git a/lib/std/zig/render.zig b/lib/std/zig/render.zig
index 1e1552dae4..9ca6d4450c 100644
--- a/lib/std/zig/render.zig
+++ b/lib/std/zig/render.zig
@@ -13,6 +13,9 @@ pub const Error = error{
 
 /// Returns whether anything changed
 pub fn render(allocator: *mem.Allocator, stream: var, tree: *ast.Tree) (@TypeOf(stream).Error || Error)!bool {
+    // cannot render an invalid tree
+    std.debug.assert(tree.errors.len == 0);
+
     // make a passthrough stream that checks whether something changed
     const MyStream = struct {
         const MyStream = @This();
@@ -391,11 +394,15 @@ fn renderExpression(
             try renderToken(tree, stream, comptime_node.comptime_token, indent, start_col, Space.Space);
             return renderExpression(allocator, stream, tree, indent, start_col, comptime_node.expr, space);
         },
-        .Noasync => {
-            const noasync_node = @fieldParentPtr(ast.Node.Noasync, "base", base);
-
-            try renderToken(tree, stream, noasync_node.noasync_token, indent, start_col, Space.Space);
-            return renderExpression(allocator, stream, tree, indent, start_col, noasync_node.expr, space);
+        .Nosuspend => {
+            const nosuspend_node = @fieldParentPtr(ast.Node.Nosuspend, "base", base);
+            if (mem.eql(u8, tree.tokenSlice(nosuspend_node.nosuspend_token), "noasync")) {
+                // TODO: remove this
+                try stream.writeAll("nosuspend ");
+            } else {
+                try renderToken(tree, stream, nosuspend_node.nosuspend_token, indent, start_col, Space.Space);
+            }
+            return renderExpression(allocator, stream, tree, indent, start_col, nosuspend_node.expr, space);
         },
 
         .Suspend => {
@@ -1409,32 +1416,15 @@ fn renderExpression(
                 try renderToken(tree, stream, visib_token_index, indent, start_col, Space.Space); // pub
             }
 
-            // Some extra machinery is needed to rewrite the old-style cc
-            // notation to the new callconv one
-            var cc_rewrite_str: ?[*:0]const u8 = null;
             if (fn_proto.extern_export_inline_token) |extern_export_inline_token| {
-                const tok = tree.tokens.at(extern_export_inline_token);
-                if (tok.id != .Keyword_extern or fn_proto.body_node == null) {
-                    try renderToken(tree, stream, extern_export_inline_token, indent, start_col, Space.Space); // extern/export
-                } else {
-                    cc_rewrite_str = ".C";
-                    fn_proto.lib_name = null;
-                }
+                if (!fn_proto.is_extern_prototype)
+                    try renderToken(tree, stream, extern_export_inline_token, indent, start_col, Space.Space); // extern/export/inline
             }
 
             if (fn_proto.lib_name) |lib_name| {
                 try renderExpression(allocator, stream, tree, indent, start_col, lib_name, Space.Space);
             }
 
-            if (fn_proto.cc_token) |cc_token| {
-                var str = tree.tokenSlicePtr(tree.tokens.at(cc_token));
-                if (mem.eql(u8, str, "stdcallcc")) {
-                    cc_rewrite_str = ".Stdcall";
-                } else if (mem.eql(u8, str, "nakedcc")) {
-                    cc_rewrite_str = ".Naked";
-                } else try renderToken(tree, stream, cc_token, indent, start_col, Space.Space); // stdcallcc
-            }
-
             const lparen = if (fn_proto.name_token) |name_token| blk: {
                 try renderToken(tree, stream, fn_proto.fn_token, indent, start_col, Space.Space); // fn
                 try renderToken(tree, stream, name_token, indent, start_col, Space.None); // name
@@ -1457,6 +1447,7 @@ fn renderExpression(
             else switch (fn_proto.return_type) {
                 .Explicit => |node| node.firstToken(),
                 .InferErrorSet => |node| tree.prevToken(node.firstToken()),
+                .Invalid => unreachable,
             });
             assert(tree.tokens.at(rparen).id == .RParen);
 
@@ -1524,20 +1515,21 @@ fn renderExpression(
                 try renderToken(tree, stream, callconv_lparen, indent, start_col, Space.None); // (
                 try renderExpression(allocator, stream, tree, indent, start_col, callconv_expr, Space.None);
                 try renderToken(tree, stream, callconv_rparen, indent, start_col, Space.Space); // )
-            } else if (cc_rewrite_str) |str| {
-                try stream.writeAll("callconv(");
-                try stream.writeAll(mem.spanZ(str));
-                try stream.writeAll(") ");
+            } else if (fn_proto.is_extern_prototype) {
+                try stream.writeAll("callconv(.C) ");
+            } else if (fn_proto.is_async) {
+                try stream.writeAll("callconv(.Async) ");
             }
 
             switch (fn_proto.return_type) {
-                ast.Node.FnProto.ReturnType.Explicit => |node| {
+                .Explicit => |node| {
                     return renderExpression(allocator, stream, tree, indent, start_col, node, space);
                 },
-                ast.Node.FnProto.ReturnType.InferErrorSet => |node| {
+                .InferErrorSet => |node| {
                     try renderToken(tree, stream, tree.prevToken(node.firstToken()), indent, start_col, Space.None); // !
                     return renderExpression(allocator, stream, tree, indent, start_col, node, space);
                 },
+                .Invalid => unreachable,
             }
         },
 
diff --git a/lib/std/zig/system.zig b/lib/std/zig/system.zig
index 7b05e3bcfb..92f01c4195 100644
--- a/lib/std/zig/system.zig
+++ b/lib/std/zig/system.zig
@@ -837,6 +837,7 @@ pub const NativeTargetInfo = struct {
                 error.BrokenPipe => return error.UnableToReadElfFile,
                 error.Unseekable => return error.UnableToReadElfFile,
                 error.ConnectionResetByPeer => return error.UnableToReadElfFile,
+                error.ConnectionTimedOut => return error.UnableToReadElfFile,
                 error.Unexpected => return error.Unexpected,
                 error.InputOutput => return error.FileSystem,
             };
diff --git a/lib/std/zig/system/macos.zig b/lib/std/zig/system/macos.zig
index 3261fdbf4c..dd34fe26f9 100644
--- a/lib/std/zig/system/macos.zig
+++ b/lib/std/zig/system/macos.zig
@@ -39,7 +39,7 @@ pub fn version_from_build(build: []const u8) !std.builtin.Version {
             zend += 1;
         }
         if (zend == yindex + 1) return error.InvalidVersion;
-        const z = std.fmt.parseUnsigned(u16, build[yindex + 1..zend], 10) catch return error.InvalidVersion;
+        const z = std.fmt.parseUnsigned(u16, build[yindex + 1 .. zend], 10) catch return error.InvalidVersion;
 
         result.patch = switch (result.minor) {
             // TODO: compiler complains without explicit @as() coercion
@@ -97,7 +97,9 @@ pub fn version_from_build(build: []const u8) !std.builtin.Version {
             4 => @as(u32, switch (y) { // Tiger: 10.4
                 'A' => 0,
                 'B' => 1,
-                'C', 'E', => 2,
+                'C',
+                'E',
+                => 2,
                 'F' => 3,
                 'G' => @as(u32, block: {
                     if (z >= 1454) break :block 5;
@@ -105,7 +107,10 @@ pub fn version_from_build(build: []const u8) !std.builtin.Version {
                 }),
                 'H' => 5,
                 'I' => 6,
-                'J', 'K', 'N', => 7,
+                'J',
+                'K',
+                'N',
+                => 7,
                 'L' => 8,
                 'P' => 9,
                 'R' => 10,
@@ -438,7 +443,7 @@ test "version_from_build" {
     for (known) |pair| {
         var buf: [32]u8 = undefined;
         const ver = try version_from_build(pair[0]);
-        const sver = try std.fmt.bufPrint(buf[0..], "{}.{}.{}", .{ver.major, ver.minor, ver.patch});
+        const sver = try std.fmt.bufPrint(buf[0..], "{}.{}.{}", .{ ver.major, ver.minor, ver.patch });
         std.testing.expect(std.mem.eql(u8, sver, pair[1]));
     }
 }
diff --git a/lib/std/zig/tokenizer.zig b/lib/std/zig/tokenizer.zig
index 99574f2a98..160530f459 100644
--- a/lib/std/zig/tokenizer.zig
+++ b/lib/std/zig/tokenizer.zig
@@ -47,10 +47,10 @@ pub const Token = struct {
         Keyword.init("for", .Keyword_for),
         Keyword.init("if", .Keyword_if),
         Keyword.init("inline", .Keyword_inline),
-        Keyword.init("nakedcc", .Keyword_nakedcc),
         Keyword.init("noalias", .Keyword_noalias),
-        Keyword.init("noasync", .Keyword_noasync),
+        Keyword.init("noasync", .Keyword_nosuspend), // TODO: remove this
         Keyword.init("noinline", .Keyword_noinline),
+        Keyword.init("nosuspend", .Keyword_nosuspend),
         Keyword.init("null", .Keyword_null),
         Keyword.init("or", .Keyword_or),
         Keyword.init("orelse", .Keyword_orelse),
@@ -59,7 +59,6 @@ pub const Token = struct {
         Keyword.init("resume", .Keyword_resume),
         Keyword.init("return", .Keyword_return),
         Keyword.init("linksection", .Keyword_linksection),
-        Keyword.init("stdcallcc", .Keyword_stdcallcc),
         Keyword.init("struct", .Keyword_struct),
         Keyword.init("suspend", .Keyword_suspend),
         Keyword.init("switch", .Keyword_switch),
@@ -180,10 +179,9 @@ pub const Token = struct {
         Keyword_for,
         Keyword_if,
         Keyword_inline,
-        Keyword_nakedcc,
         Keyword_noalias,
-        Keyword_noasync,
         Keyword_noinline,
+        Keyword_nosuspend,
         Keyword_null,
         Keyword_or,
         Keyword_orelse,
@@ -193,7 +191,6 @@ pub const Token = struct {
         Keyword_resume,
         Keyword_return,
         Keyword_linksection,
-        Keyword_stdcallcc,
         Keyword_struct,
         Keyword_suspend,
         Keyword_switch,
@@ -305,10 +302,9 @@ pub const Token = struct {
                 .Keyword_for => "for",
                 .Keyword_if => "if",
                 .Keyword_inline => "inline",
-                .Keyword_nakedcc => "nakedcc",
                 .Keyword_noalias => "noalias",
-                .Keyword_noasync => "noasync",
                 .Keyword_noinline => "noinline",
+                .Keyword_nosuspend => "nosuspend",
                 .Keyword_null => "null",
                 .Keyword_or => "or",
                 .Keyword_orelse => "orelse",
@@ -317,7 +313,6 @@ pub const Token = struct {
                 .Keyword_resume => "resume",
                 .Keyword_return => "return",
                 .Keyword_linksection => "linksection",
-                .Keyword_stdcallcc => "stdcallcc",
                 .Keyword_struct => "struct",
                 .Keyword_suspend => "suspend",
                 .Keyword_switch => "switch",
@@ -358,64 +353,64 @@ pub const Tokenizer = struct {
     }
 
     const State = enum {
-        Start,
-        Identifier,
-        Builtin,
-        StringLiteral,
-        StringLiteralBackslash,
-        MultilineStringLiteralLine,
-        CharLiteral,
-        CharLiteralBackslash,
-        CharLiteralHexEscape,
-        CharLiteralUnicodeEscapeSawU,
-        CharLiteralUnicodeEscape,
-        CharLiteralUnicodeInvalid,
-        CharLiteralUnicode,
-        CharLiteralEnd,
-        Backslash,
-        Equal,
-        Bang,
-        Pipe,
-        Minus,
-        MinusPercent,
-        Asterisk,
-        AsteriskPercent,
-        Slash,
-        LineCommentStart,
-        LineComment,
-        DocCommentStart,
-        DocComment,
-        ContainerDocComment,
-        Zero,
-        IntegerLiteralDec,
-        IntegerLiteralDecNoUnderscore,
-        IntegerLiteralBin,
-        IntegerLiteralBinNoUnderscore,
-        IntegerLiteralOct,
-        IntegerLiteralOctNoUnderscore,
-        IntegerLiteralHex,
-        IntegerLiteralHexNoUnderscore,
-        NumberDotDec,
-        NumberDotHex,
-        FloatFractionDec,
-        FloatFractionDecNoUnderscore,
-        FloatFractionHex,
-        FloatFractionHexNoUnderscore,
-        FloatExponentUnsigned,
-        FloatExponentNumber,
-        FloatExponentNumberNoUnderscore,
-        Ampersand,
-        Caret,
-        Percent,
-        Plus,
-        PlusPercent,
-        AngleBracketLeft,
-        AngleBracketAngleBracketLeft,
-        AngleBracketRight,
-        AngleBracketAngleBracketRight,
-        Period,
-        Period2,
-        SawAtSign,
+        start,
+        identifier,
+        builtin,
+        string_literal,
+        string_literal_backslash,
+        multiline_string_literal_line,
+        char_literal,
+        char_literal_backslash,
+        char_literal_hex_escape,
+        char_literal_unicode_escape_saw_u,
+        char_literal_unicode_escape,
+        char_literal_unicode_invalid,
+        char_literal_unicode,
+        char_literal_end,
+        backslash,
+        equal,
+        bang,
+        pipe,
+        minus,
+        minus_percent,
+        asterisk,
+        asterisk_percent,
+        slash,
+        line_comment_start,
+        line_comment,
+        doc_comment_start,
+        doc_comment,
+        container_doc_comment,
+        zero,
+        int_literal_dec,
+        int_literal_dec_no_underscore,
+        int_literal_bin,
+        int_literal_bin_no_underscore,
+        int_literal_oct,
+        int_literal_oct_no_underscore,
+        int_literal_hex,
+        int_literal_hex_no_underscore,
+        num_dot_dec,
+        num_dot_hex,
+        float_fraction_dec,
+        float_fraction_dec_no_underscore,
+        float_fraction_hex,
+        float_fraction_hex_no_underscore,
+        float_exponent_unsigned,
+        float_exponent_num,
+        float_exponent_num_no_underscore,
+        ampersand,
+        caret,
+        percent,
+        plus,
+        plus_percent,
+        angle_bracket_left,
+        angle_bracket_angle_bracket_left,
+        angle_bracket_right,
+        angle_bracket_angle_bracket_right,
+        period,
+        period_2,
+        saw_at_sign,
     };
 
     fn isIdentifierChar(char: u8) bool {
@@ -428,9 +423,9 @@ pub const Tokenizer = struct {
             return token;
         }
         const start_index = self.index;
-        var state = State.Start;
+        var state: State = .start;
         var result = Token{
-            .id = Token.Id.Eof,
+            .id = .Eof,
             .start = self.index,
             .end = undefined,
         };
@@ -439,40 +434,40 @@ pub const Tokenizer = struct {
         while (self.index < self.buffer.len) : (self.index += 1) {
             const c = self.buffer[self.index];
             switch (state) {
-                State.Start => switch (c) {
+                .start => switch (c) {
                     ' ', '\n', '\t', '\r' => {
                         result.start = self.index + 1;
                     },
                     '"' => {
-                        state = State.StringLiteral;
-                        result.id = Token.Id.StringLiteral;
+                        state = .string_literal;
+                        result.id = .StringLiteral;
                     },
                     '\'' => {
-                        state = State.CharLiteral;
+                        state = .char_literal;
                     },
                     'a'...'z', 'A'...'Z', '_' => {
-                        state = State.Identifier;
-                        result.id = Token.Id.Identifier;
+                        state = .identifier;
+                        result.id = .Identifier;
                     },
                     '@' => {
-                        state = State.SawAtSign;
+                        state = .saw_at_sign;
                     },
                     '=' => {
-                        state = State.Equal;
+                        state = .equal;
                     },
                     '!' => {
-                        state = State.Bang;
+                        state = .bang;
                     },
                     '|' => {
-                        state = State.Pipe;
+                        state = .pipe;
                     },
                     '(' => {
-                        result.id = Token.Id.LParen;
+                        result.id = .LParen;
                         self.index += 1;
                         break;
                     },
                     ')' => {
-                        result.id = Token.Id.RParen;
+                        result.id = .RParen;
                         self.index += 1;
                         break;
                     },
@@ -482,213 +477,213 @@ pub const Tokenizer = struct {
                         break;
                     },
                     ']' => {
-                        result.id = Token.Id.RBracket;
+                        result.id = .RBracket;
                         self.index += 1;
                         break;
                     },
                     ';' => {
-                        result.id = Token.Id.Semicolon;
+                        result.id = .Semicolon;
                         self.index += 1;
                         break;
                     },
                     ',' => {
-                        result.id = Token.Id.Comma;
+                        result.id = .Comma;
                         self.index += 1;
                         break;
                     },
                     '?' => {
-                        result.id = Token.Id.QuestionMark;
+                        result.id = .QuestionMark;
                         self.index += 1;
                         break;
                     },
                     ':' => {
-                        result.id = Token.Id.Colon;
+                        result.id = .Colon;
                         self.index += 1;
                         break;
                     },
                     '%' => {
-                        state = State.Percent;
+                        state = .percent;
                     },
                     '*' => {
-                        state = State.Asterisk;
+                        state = .asterisk;
                     },
                     '+' => {
-                        state = State.Plus;
+                        state = .plus;
                     },
                     '<' => {
-                        state = State.AngleBracketLeft;
+                        state = .angle_bracket_left;
                     },
                     '>' => {
-                        state = State.AngleBracketRight;
+                        state = .angle_bracket_right;
                     },
                     '^' => {
-                        state = State.Caret;
+                        state = .caret;
                     },
                     '\\' => {
-                        state = State.Backslash;
-                        result.id = Token.Id.MultilineStringLiteralLine;
+                        state = .backslash;
+                        result.id = .MultilineStringLiteralLine;
                     },
                     '{' => {
-                        result.id = Token.Id.LBrace;
+                        result.id = .LBrace;
                         self.index += 1;
                         break;
                     },
                     '}' => {
-                        result.id = Token.Id.RBrace;
+                        result.id = .RBrace;
                         self.index += 1;
                         break;
                     },
                     '~' => {
-                        result.id = Token.Id.Tilde;
+                        result.id = .Tilde;
                         self.index += 1;
                         break;
                     },
                     '.' => {
-                        state = State.Period;
+                        state = .period;
                     },
                     '-' => {
-                        state = State.Minus;
+                        state = .minus;
                     },
                     '/' => {
-                        state = State.Slash;
+                        state = .slash;
                     },
                     '&' => {
-                        state = State.Ampersand;
+                        state = .ampersand;
                     },
                     '0' => {
-                        state = State.Zero;
-                        result.id = Token.Id.IntegerLiteral;
+                        state = .zero;
+                        result.id = .IntegerLiteral;
                     },
                     '1'...'9' => {
-                        state = State.IntegerLiteralDec;
-                        result.id = Token.Id.IntegerLiteral;
+                        state = .int_literal_dec;
+                        result.id = .IntegerLiteral;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         self.index += 1;
                         break;
                     },
                 },
 
-                State.SawAtSign => switch (c) {
+                .saw_at_sign => switch (c) {
                     '"' => {
-                        result.id = Token.Id.Identifier;
-                        state = State.StringLiteral;
+                        result.id = .Identifier;
+                        state = .string_literal;
                     },
                     else => {
                         // reinterpret as a builtin
                         self.index -= 1;
-                        state = State.Builtin;
-                        result.id = Token.Id.Builtin;
+                        state = .builtin;
+                        result.id = .Builtin;
                     },
                 },
 
-                State.Ampersand => switch (c) {
+                .ampersand => switch (c) {
                     '&' => {
-                        result.id = Token.Id.Invalid_ampersands;
+                        result.id = .Invalid_ampersands;
                         self.index += 1;
                         break;
                     },
                     '=' => {
-                        result.id = Token.Id.AmpersandEqual;
+                        result.id = .AmpersandEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Ampersand;
+                        result.id = .Ampersand;
                         break;
                     },
                 },
 
-                State.Asterisk => switch (c) {
+                .asterisk => switch (c) {
                     '=' => {
-                        result.id = Token.Id.AsteriskEqual;
+                        result.id = .AsteriskEqual;
                         self.index += 1;
                         break;
                     },
                     '*' => {
-                        result.id = Token.Id.AsteriskAsterisk;
+                        result.id = .AsteriskAsterisk;
                         self.index += 1;
                         break;
                     },
                     '%' => {
-                        state = State.AsteriskPercent;
+                        state = .asterisk_percent;
                     },
                     else => {
-                        result.id = Token.Id.Asterisk;
+                        result.id = .Asterisk;
                         break;
                     },
                 },
 
-                State.AsteriskPercent => switch (c) {
+                .asterisk_percent => switch (c) {
                     '=' => {
-                        result.id = Token.Id.AsteriskPercentEqual;
+                        result.id = .AsteriskPercentEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.AsteriskPercent;
+                        result.id = .AsteriskPercent;
                         break;
                     },
                 },
 
-                State.Percent => switch (c) {
+                .percent => switch (c) {
                     '=' => {
-                        result.id = Token.Id.PercentEqual;
+                        result.id = .PercentEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Percent;
+                        result.id = .Percent;
                         break;
                     },
                 },
 
-                State.Plus => switch (c) {
+                .plus => switch (c) {
                     '=' => {
-                        result.id = Token.Id.PlusEqual;
+                        result.id = .PlusEqual;
                         self.index += 1;
                         break;
                     },
                     '+' => {
-                        result.id = Token.Id.PlusPlus;
+                        result.id = .PlusPlus;
                         self.index += 1;
                         break;
                     },
                     '%' => {
-                        state = State.PlusPercent;
+                        state = .plus_percent;
                     },
                     else => {
-                        result.id = Token.Id.Plus;
+                        result.id = .Plus;
                         break;
                     },
                 },
 
-                State.PlusPercent => switch (c) {
+                .plus_percent => switch (c) {
                     '=' => {
-                        result.id = Token.Id.PlusPercentEqual;
+                        result.id = .PlusPercentEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.PlusPercent;
+                        result.id = .PlusPercent;
                         break;
                     },
                 },
 
-                State.Caret => switch (c) {
+                .caret => switch (c) {
                     '=' => {
-                        result.id = Token.Id.CaretEqual;
+                        result.id = .CaretEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Caret;
+                        result.id = .Caret;
                         break;
                     },
                 },
 
-                State.Identifier => switch (c) {
+                .identifier => switch (c) {
                     'a'...'z', 'A'...'Z', '_', '0'...'9' => {},
                     else => {
                         if (Token.getKeyword(self.buffer[result.start..self.index])) |id| {
@@ -697,19 +692,19 @@ pub const Tokenizer = struct {
                         break;
                     },
                 },
-                State.Builtin => switch (c) {
+                .builtin => switch (c) {
                     'a'...'z', 'A'...'Z', '_', '0'...'9' => {},
                     else => break,
                 },
-                State.Backslash => switch (c) {
+                .backslash => switch (c) {
                     '\\' => {
-                        state = State.MultilineStringLiteralLine;
+                        state = .multiline_string_literal_line;
                     },
                     else => break,
                 },
-                State.StringLiteral => switch (c) {
+                .string_literal => switch (c) {
                     '\\' => {
-                        state = State.StringLiteralBackslash;
+                        state = .string_literal_backslash;
                     },
                     '"' => {
                         self.index += 1;
@@ -719,98 +714,98 @@ pub const Tokenizer = struct {
                     else => self.checkLiteralCharacter(),
                 },
 
-                State.StringLiteralBackslash => switch (c) {
+                .string_literal_backslash => switch (c) {
                     '\n', '\r' => break, // Look for this error later.
                     else => {
-                        state = State.StringLiteral;
+                        state = .string_literal;
                     },
                 },
 
-                State.CharLiteral => switch (c) {
+                .char_literal => switch (c) {
                     '\\' => {
-                        state = State.CharLiteralBackslash;
+                        state = .char_literal_backslash;
                     },
                     '\'', 0x80...0xbf, 0xf8...0xff => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                     0xc0...0xdf => { // 110xxxxx
                         remaining_code_units = 1;
-                        state = State.CharLiteralUnicode;
+                        state = .char_literal_unicode;
                     },
                     0xe0...0xef => { // 1110xxxx
                         remaining_code_units = 2;
-                        state = State.CharLiteralUnicode;
+                        state = .char_literal_unicode;
                     },
                     0xf0...0xf7 => { // 11110xxx
                         remaining_code_units = 3;
-                        state = State.CharLiteralUnicode;
+                        state = .char_literal_unicode;
                     },
                     else => {
-                        state = State.CharLiteralEnd;
+                        state = .char_literal_end;
                     },
                 },
 
-                State.CharLiteralBackslash => switch (c) {
+                .char_literal_backslash => switch (c) {
                     '\n' => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                     'x' => {
-                        state = State.CharLiteralHexEscape;
+                        state = .char_literal_hex_escape;
                         seen_escape_digits = 0;
                     },
                     'u' => {
-                        state = State.CharLiteralUnicodeEscapeSawU;
+                        state = .char_literal_unicode_escape_saw_u;
                     },
                     else => {
-                        state = State.CharLiteralEnd;
+                        state = .char_literal_end;
                     },
                 },
 
-                State.CharLiteralHexEscape => switch (c) {
+                .char_literal_hex_escape => switch (c) {
                     '0'...'9', 'a'...'f', 'A'...'F' => {
                         seen_escape_digits += 1;
                         if (seen_escape_digits == 2) {
-                            state = State.CharLiteralEnd;
+                            state = .char_literal_end;
                         }
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
 
-                State.CharLiteralUnicodeEscapeSawU => switch (c) {
+                .char_literal_unicode_escape_saw_u => switch (c) {
                     '{' => {
-                        state = State.CharLiteralUnicodeEscape;
+                        state = .char_literal_unicode_escape;
                         seen_escape_digits = 0;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
-                        state = State.CharLiteralUnicodeInvalid;
+                        result.id = .Invalid;
+                        state = .char_literal_unicode_invalid;
                     },
                 },
 
-                State.CharLiteralUnicodeEscape => switch (c) {
+                .char_literal_unicode_escape => switch (c) {
                     '0'...'9', 'a'...'f', 'A'...'F' => {
                         seen_escape_digits += 1;
                     },
                     '}' => {
                         if (seen_escape_digits == 0) {
-                            result.id = Token.Id.Invalid;
-                            state = State.CharLiteralUnicodeInvalid;
+                            result.id = .Invalid;
+                            state = .char_literal_unicode_invalid;
                         } else {
-                            state = State.CharLiteralEnd;
+                            state = .char_literal_end;
                         }
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
-                        state = State.CharLiteralUnicodeInvalid;
+                        result.id = .Invalid;
+                        state = .char_literal_unicode_invalid;
                     },
                 },
 
-                State.CharLiteralUnicodeInvalid => switch (c) {
+                .char_literal_unicode_invalid => switch (c) {
                     // Keep consuming characters until an obvious stopping point.
                     // This consolidates e.g. `u{0ab1Q}` into a single invalid token
                     // instead of creating the tokens `u{0ab1`, `Q`, `}`
@@ -818,32 +813,32 @@ pub const Tokenizer = struct {
                     else => break,
                 },
 
-                State.CharLiteralEnd => switch (c) {
+                .char_literal_end => switch (c) {
                     '\'' => {
-                        result.id = Token.Id.CharLiteral;
+                        result.id = .CharLiteral;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
 
-                State.CharLiteralUnicode => switch (c) {
+                .char_literal_unicode => switch (c) {
                     0x80...0xbf => {
                         remaining_code_units -= 1;
                         if (remaining_code_units == 0) {
-                            state = State.CharLiteralEnd;
+                            state = .char_literal_end;
                         }
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
 
-                State.MultilineStringLiteralLine => switch (c) {
+                .multiline_string_literal_line => switch (c) {
                     '\n' => {
                         self.index += 1;
                         break;
@@ -852,449 +847,449 @@ pub const Tokenizer = struct {
                     else => self.checkLiteralCharacter(),
                 },
 
-                State.Bang => switch (c) {
+                .bang => switch (c) {
                     '=' => {
-                        result.id = Token.Id.BangEqual;
+                        result.id = .BangEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Bang;
+                        result.id = .Bang;
                         break;
                     },
                 },
 
-                State.Pipe => switch (c) {
+                .pipe => switch (c) {
                     '=' => {
-                        result.id = Token.Id.PipeEqual;
+                        result.id = .PipeEqual;
                         self.index += 1;
                         break;
                     },
                     '|' => {
-                        result.id = Token.Id.PipePipe;
+                        result.id = .PipePipe;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Pipe;
+                        result.id = .Pipe;
                         break;
                     },
                 },
 
-                State.Equal => switch (c) {
+                .equal => switch (c) {
                     '=' => {
-                        result.id = Token.Id.EqualEqual;
+                        result.id = .EqualEqual;
                         self.index += 1;
                         break;
                     },
                     '>' => {
-                        result.id = Token.Id.EqualAngleBracketRight;
+                        result.id = .EqualAngleBracketRight;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Equal;
+                        result.id = .Equal;
                         break;
                     },
                 },
 
-                State.Minus => switch (c) {
+                .minus => switch (c) {
                     '>' => {
-                        result.id = Token.Id.Arrow;
+                        result.id = .Arrow;
                         self.index += 1;
                         break;
                     },
                     '=' => {
-                        result.id = Token.Id.MinusEqual;
+                        result.id = .MinusEqual;
                         self.index += 1;
                         break;
                     },
                     '%' => {
-                        state = State.MinusPercent;
+                        state = .minus_percent;
                     },
                     else => {
-                        result.id = Token.Id.Minus;
+                        result.id = .Minus;
                         break;
                     },
                 },
 
-                State.MinusPercent => switch (c) {
+                .minus_percent => switch (c) {
                     '=' => {
-                        result.id = Token.Id.MinusPercentEqual;
+                        result.id = .MinusPercentEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.MinusPercent;
+                        result.id = .MinusPercent;
                         break;
                     },
                 },
 
-                State.AngleBracketLeft => switch (c) {
+                .angle_bracket_left => switch (c) {
                     '<' => {
-                        state = State.AngleBracketAngleBracketLeft;
+                        state = .angle_bracket_angle_bracket_left;
                     },
                     '=' => {
-                        result.id = Token.Id.AngleBracketLeftEqual;
+                        result.id = .AngleBracketLeftEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.AngleBracketLeft;
+                        result.id = .AngleBracketLeft;
                         break;
                     },
                 },
 
-                State.AngleBracketAngleBracketLeft => switch (c) {
+                .angle_bracket_angle_bracket_left => switch (c) {
                     '=' => {
-                        result.id = Token.Id.AngleBracketAngleBracketLeftEqual;
+                        result.id = .AngleBracketAngleBracketLeftEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.AngleBracketAngleBracketLeft;
+                        result.id = .AngleBracketAngleBracketLeft;
                         break;
                     },
                 },
 
-                State.AngleBracketRight => switch (c) {
+                .angle_bracket_right => switch (c) {
                     '>' => {
-                        state = State.AngleBracketAngleBracketRight;
+                        state = .angle_bracket_angle_bracket_right;
                     },
                     '=' => {
-                        result.id = Token.Id.AngleBracketRightEqual;
+                        result.id = .AngleBracketRightEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.AngleBracketRight;
+                        result.id = .AngleBracketRight;
                         break;
                     },
                 },
 
-                State.AngleBracketAngleBracketRight => switch (c) {
+                .angle_bracket_angle_bracket_right => switch (c) {
                     '=' => {
-                        result.id = Token.Id.AngleBracketAngleBracketRightEqual;
+                        result.id = .AngleBracketAngleBracketRightEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.AngleBracketAngleBracketRight;
+                        result.id = .AngleBracketAngleBracketRight;
                         break;
                     },
                 },
 
-                State.Period => switch (c) {
+                .period => switch (c) {
                     '.' => {
-                        state = State.Period2;
+                        state = .period_2;
                     },
                     '*' => {
-                        result.id = Token.Id.PeriodAsterisk;
+                        result.id = .PeriodAsterisk;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Period;
+                        result.id = .Period;
                         break;
                     },
                 },
 
-                State.Period2 => switch (c) {
+                .period_2 => switch (c) {
                     '.' => {
-                        result.id = Token.Id.Ellipsis3;
+                        result.id = .Ellipsis3;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Ellipsis2;
+                        result.id = .Ellipsis2;
                         break;
                     },
                 },
 
-                State.Slash => switch (c) {
+                .slash => switch (c) {
                     '/' => {
-                        state = State.LineCommentStart;
-                        result.id = Token.Id.LineComment;
+                        state = .line_comment_start;
+                        result.id = .LineComment;
                     },
                     '=' => {
-                        result.id = Token.Id.SlashEqual;
+                        result.id = .SlashEqual;
                         self.index += 1;
                         break;
                     },
                     else => {
-                        result.id = Token.Id.Slash;
+                        result.id = .Slash;
                         break;
                     },
                 },
-                State.LineCommentStart => switch (c) {
+                .line_comment_start => switch (c) {
                     '/' => {
-                        state = State.DocCommentStart;
+                        state = .doc_comment_start;
                     },
                     '!' => {
-                        result.id = Token.Id.ContainerDocComment;
-                        state = State.ContainerDocComment;
+                        result.id = .ContainerDocComment;
+                        state = .container_doc_comment;
                     },
                     '\n' => break,
                     else => {
-                        state = State.LineComment;
+                        state = .line_comment;
                         self.checkLiteralCharacter();
                     },
                 },
-                State.DocCommentStart => switch (c) {
+                .doc_comment_start => switch (c) {
                     '/' => {
-                        state = State.LineComment;
+                        state = .line_comment;
                     },
                     '\n' => {
-                        result.id = Token.Id.DocComment;
+                        result.id = .DocComment;
                         break;
                     },
                     else => {
-                        state = State.DocComment;
-                        result.id = Token.Id.DocComment;
+                        state = .doc_comment;
+                        result.id = .DocComment;
                         self.checkLiteralCharacter();
                     },
                 },
-                State.LineComment, State.DocComment, State.ContainerDocComment => switch (c) {
+                .line_comment, .doc_comment, .container_doc_comment => switch (c) {
                     '\n' => break,
                     else => self.checkLiteralCharacter(),
                 },
-                State.Zero => switch (c) {
+                .zero => switch (c) {
                     'b' => {
-                        state = State.IntegerLiteralBinNoUnderscore;
+                        state = .int_literal_bin_no_underscore;
                     },
                     'o' => {
-                        state = State.IntegerLiteralOctNoUnderscore;
+                        state = .int_literal_oct_no_underscore;
                     },
                     'x' => {
-                        state = State.IntegerLiteralHexNoUnderscore;
+                        state = .int_literal_hex_no_underscore;
                     },
                     '0'...'9', '_', '.', 'e', 'E' => {
                         // reinterpret as a decimal number
                         self.index -= 1;
-                        state = State.IntegerLiteralDec;
+                        state = .int_literal_dec;
                     },
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.IntegerLiteralBinNoUnderscore => switch (c) {
+                .int_literal_bin_no_underscore => switch (c) {
                     '0'...'1' => {
-                        state = State.IntegerLiteralBin;
+                        state = .int_literal_bin;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
-                State.IntegerLiteralBin => switch (c) {
+                .int_literal_bin => switch (c) {
                     '_' => {
-                        state = State.IntegerLiteralBinNoUnderscore;
+                        state = .int_literal_bin_no_underscore;
                     },
                     '0'...'1' => {},
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.IntegerLiteralOctNoUnderscore => switch (c) {
+                .int_literal_oct_no_underscore => switch (c) {
                     '0'...'7' => {
-                        state = State.IntegerLiteralOct;
+                        state = .int_literal_oct;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
-                State.IntegerLiteralOct => switch (c) {
+                .int_literal_oct => switch (c) {
                     '_' => {
-                        state = State.IntegerLiteralOctNoUnderscore;
+                        state = .int_literal_oct_no_underscore;
                     },
                     '0'...'7' => {},
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.IntegerLiteralDecNoUnderscore => switch (c) {
+                .int_literal_dec_no_underscore => switch (c) {
                     '0'...'9' => {
-                        state = State.IntegerLiteralDec;
+                        state = .int_literal_dec;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
-                State.IntegerLiteralDec => switch (c) {
+                .int_literal_dec => switch (c) {
                     '_' => {
-                        state = State.IntegerLiteralDecNoUnderscore;
+                        state = .int_literal_dec_no_underscore;
                     },
                     '.' => {
-                        state = State.NumberDotDec;
-                        result.id = Token.Id.FloatLiteral;
+                        state = .num_dot_dec;
+                        result.id = .FloatLiteral;
                     },
                     'e', 'E' => {
-                        state = State.FloatExponentUnsigned;
-                        result.id = Token.Id.FloatLiteral;
+                        state = .float_exponent_unsigned;
+                        result.id = .FloatLiteral;
                     },
                     '0'...'9' => {},
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.IntegerLiteralHexNoUnderscore => switch (c) {
+                .int_literal_hex_no_underscore => switch (c) {
                     '0'...'9', 'a'...'f', 'A'...'F' => {
-                        state = State.IntegerLiteralHex;
+                        state = .int_literal_hex;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
-                State.IntegerLiteralHex => switch (c) {
+                .int_literal_hex => switch (c) {
                     '_' => {
-                        state = State.IntegerLiteralHexNoUnderscore;
+                        state = .int_literal_hex_no_underscore;
                     },
                     '.' => {
-                        state = State.NumberDotHex;
-                        result.id = Token.Id.FloatLiteral;
+                        state = .num_dot_hex;
+                        result.id = .FloatLiteral;
                     },
                     'p', 'P' => {
-                        state = State.FloatExponentUnsigned;
-                        result.id = Token.Id.FloatLiteral;
+                        state = .float_exponent_unsigned;
+                        result.id = .FloatLiteral;
                     },
                     '0'...'9', 'a'...'f', 'A'...'F' => {},
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.NumberDotDec => switch (c) {
+                .num_dot_dec => switch (c) {
                     '.' => {
                         self.index -= 1;
-                        state = State.Start;
+                        state = .start;
                         break;
                     },
                     'e', 'E' => {
-                        state = State.FloatExponentUnsigned;
+                        state = .float_exponent_unsigned;
                     },
                     '0'...'9' => {
-                        result.id = Token.Id.FloatLiteral;
-                        state = State.FloatFractionDec;
+                        result.id = .FloatLiteral;
+                        state = .float_fraction_dec;
                     },
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.NumberDotHex => switch (c) {
+                .num_dot_hex => switch (c) {
                     '.' => {
                         self.index -= 1;
-                        state = State.Start;
+                        state = .start;
                         break;
                     },
                     'p', 'P' => {
-                        state = State.FloatExponentUnsigned;
+                        state = .float_exponent_unsigned;
                     },
                     '0'...'9', 'a'...'f', 'A'...'F' => {
-                        result.id = Token.Id.FloatLiteral;
-                        state = State.FloatFractionHex;
+                        result.id = .FloatLiteral;
+                        state = .float_fraction_hex;
                     },
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.FloatFractionDecNoUnderscore => switch (c) {
+                .float_fraction_dec_no_underscore => switch (c) {
                     '0'...'9' => {
-                        state = State.FloatFractionDec;
+                        state = .float_fraction_dec;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
-                State.FloatFractionDec => switch (c) {
+                .float_fraction_dec => switch (c) {
                     '_' => {
-                        state = State.FloatFractionDecNoUnderscore;
+                        state = .float_fraction_dec_no_underscore;
                     },
                     'e', 'E' => {
-                        state = State.FloatExponentUnsigned;
+                        state = .float_exponent_unsigned;
                     },
                     '0'...'9' => {},
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.FloatFractionHexNoUnderscore => switch (c) {
+                .float_fraction_hex_no_underscore => switch (c) {
                     '0'...'9', 'a'...'f', 'A'...'F' => {
-                        state = State.FloatFractionHex;
+                        state = .float_fraction_hex;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
-                State.FloatFractionHex => switch (c) {
+                .float_fraction_hex => switch (c) {
                     '_' => {
-                        state = State.FloatFractionHexNoUnderscore;
+                        state = .float_fraction_hex_no_underscore;
                     },
                     'p', 'P' => {
-                        state = State.FloatExponentUnsigned;
+                        state = .float_exponent_unsigned;
                     },
                     '0'...'9', 'a'...'f', 'A'...'F' => {},
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
                 },
-                State.FloatExponentUnsigned => switch (c) {
+                .float_exponent_unsigned => switch (c) {
                     '+', '-' => {
-                        state = State.FloatExponentNumberNoUnderscore;
+                        state = .float_exponent_num_no_underscore;
                     },
                     else => {
                         // reinterpret as a normal exponent number
                         self.index -= 1;
-                        state = State.FloatExponentNumberNoUnderscore;
+                        state = .float_exponent_num_no_underscore;
                     },
                 },
-                State.FloatExponentNumberNoUnderscore => switch (c) {
+                .float_exponent_num_no_underscore => switch (c) {
                     '0'...'9' => {
-                        state = State.FloatExponentNumber;
+                        state = .float_exponent_num;
                     },
                     else => {
-                        result.id = Token.Id.Invalid;
+                        result.id = .Invalid;
                         break;
                     },
                 },
-                State.FloatExponentNumber => switch (c) {
+                .float_exponent_num => switch (c) {
                     '_' => {
-                        state = State.FloatExponentNumberNoUnderscore;
+                        state = .float_exponent_num_no_underscore;
                     },
                     '0'...'9' => {},
                     else => {
                         if (isIdentifierChar(c)) {
-                            result.id = Token.Id.Invalid;
+                            result.id = .Invalid;
                         }
                         break;
                     },
@@ -1302,123 +1297,123 @@ pub const Tokenizer = struct {
             }
         } else if (self.index == self.buffer.len) {
             switch (state) {
-                State.Start,
-                State.IntegerLiteralDec,
-                State.IntegerLiteralBin,
-                State.IntegerLiteralOct,
-                State.IntegerLiteralHex,
-                State.NumberDotDec,
-                State.NumberDotHex,
-                State.FloatFractionDec,
-                State.FloatFractionHex,
-                State.FloatExponentNumber,
-                State.StringLiteral, // find this error later
-                State.MultilineStringLiteralLine,
-                State.Builtin,
+                .start,
+                .int_literal_dec,
+                .int_literal_bin,
+                .int_literal_oct,
+                .int_literal_hex,
+                .num_dot_dec,
+                .num_dot_hex,
+                .float_fraction_dec,
+                .float_fraction_hex,
+                .float_exponent_num,
+                .string_literal, // find this error later
+                .multiline_string_literal_line,
+                .builtin,
                 => {},
 
-                State.Identifier => {
+                .identifier => {
                     if (Token.getKeyword(self.buffer[result.start..self.index])) |id| {
                         result.id = id;
                     }
                 },
-                State.LineCommentStart, State.LineComment => {
-                    result.id = Token.Id.LineComment;
-                },
-                State.DocComment, State.DocCommentStart => {
-                    result.id = Token.Id.DocComment;
-                },
-                State.ContainerDocComment => {
-                    result.id = Token.Id.ContainerDocComment;
-                },
-
-                State.IntegerLiteralDecNoUnderscore,
-                State.IntegerLiteralBinNoUnderscore,
-                State.IntegerLiteralOctNoUnderscore,
-                State.IntegerLiteralHexNoUnderscore,
-                State.FloatFractionDecNoUnderscore,
-                State.FloatFractionHexNoUnderscore,
-                State.FloatExponentNumberNoUnderscore,
-                State.FloatExponentUnsigned,
-                State.SawAtSign,
-                State.Backslash,
-                State.CharLiteral,
-                State.CharLiteralBackslash,
-                State.CharLiteralHexEscape,
-                State.CharLiteralUnicodeEscapeSawU,
-                State.CharLiteralUnicodeEscape,
-                State.CharLiteralUnicodeInvalid,
-                State.CharLiteralEnd,
-                State.CharLiteralUnicode,
-                State.StringLiteralBackslash,
+                .line_comment, .line_comment_start => {
+                    result.id = .LineComment;
+                },
+                .doc_comment, .doc_comment_start => {
+                    result.id = .DocComment;
+                },
+                .container_doc_comment => {
+                    result.id = .ContainerDocComment;
+                },
+
+                .int_literal_dec_no_underscore,
+                .int_literal_bin_no_underscore,
+                .int_literal_oct_no_underscore,
+                .int_literal_hex_no_underscore,
+                .float_fraction_dec_no_underscore,
+                .float_fraction_hex_no_underscore,
+                .float_exponent_num_no_underscore,
+                .float_exponent_unsigned,
+                .saw_at_sign,
+                .backslash,
+                .char_literal,
+                .char_literal_backslash,
+                .char_literal_hex_escape,
+                .char_literal_unicode_escape_saw_u,
+                .char_literal_unicode_escape,
+                .char_literal_unicode_invalid,
+                .char_literal_end,
+                .char_literal_unicode,
+                .string_literal_backslash,
                 => {
-                    result.id = Token.Id.Invalid;
+                    result.id = .Invalid;
                 },
 
-                State.Equal => {
-                    result.id = Token.Id.Equal;
+                .equal => {
+                    result.id = .Equal;
                 },
-                State.Bang => {
-                    result.id = Token.Id.Bang;
+                .bang => {
+                    result.id = .Bang;
                 },
-                State.Minus => {
-                    result.id = Token.Id.Minus;
+                .minus => {
+                    result.id = .Minus;
                 },
-                State.Slash => {
-                    result.id = Token.Id.Slash;
+                .slash => {
+                    result.id = .Slash;
                 },
-                State.Zero => {
-                    result.id = Token.Id.IntegerLiteral;
+                .zero => {
+                    result.id = .IntegerLiteral;
                 },
-                State.Ampersand => {
-                    result.id = Token.Id.Ampersand;
+                .ampersand => {
+                    result.id = .Ampersand;
                 },
-                State.Period => {
-                    result.id = Token.Id.Period;
+                .period => {
+                    result.id = .Period;
                 },
-                State.Period2 => {
-                    result.id = Token.Id.Ellipsis2;
+                .period_2 => {
+                    result.id = .Ellipsis2;
                 },
-                State.Pipe => {
-                    result.id = Token.Id.Pipe;
+                .pipe => {
+                    result.id = .Pipe;
                 },
-                State.AngleBracketAngleBracketRight => {
-                    result.id = Token.Id.AngleBracketAngleBracketRight;
+                .angle_bracket_angle_bracket_right => {
+                    result.id = .AngleBracketAngleBracketRight;
                 },
-                State.AngleBracketRight => {
-                    result.id = Token.Id.AngleBracketRight;
+                .angle_bracket_right => {
+                    result.id = .AngleBracketRight;
                 },
-                State.AngleBracketAngleBracketLeft => {
-                    result.id = Token.Id.AngleBracketAngleBracketLeft;
+                .angle_bracket_angle_bracket_left => {
+                    result.id = .AngleBracketAngleBracketLeft;
                 },
-                State.AngleBracketLeft => {
-                    result.id = Token.Id.AngleBracketLeft;
+                .angle_bracket_left => {
+                    result.id = .AngleBracketLeft;
                 },
-                State.PlusPercent => {
-                    result.id = Token.Id.PlusPercent;
+                .plus_percent => {
+                    result.id = .PlusPercent;
                 },
-                State.Plus => {
-                    result.id = Token.Id.Plus;
+                .plus => {
+                    result.id = .Plus;
                 },
-                State.Percent => {
-                    result.id = Token.Id.Percent;
+                .percent => {
+                    result.id = .Percent;
                 },
-                State.Caret => {
-                    result.id = Token.Id.Caret;
+                .caret => {
+                    result.id = .Caret;
                 },
-                State.AsteriskPercent => {
-                    result.id = Token.Id.AsteriskPercent;
+                .asterisk_percent => {
+                    result.id = .AsteriskPercent;
                 },
-                State.Asterisk => {
-                    result.id = Token.Id.Asterisk;
+                .asterisk => {
+                    result.id = .Asterisk;
                 },
-                State.MinusPercent => {
-                    result.id = Token.Id.MinusPercent;
+                .minus_percent => {
+                    result.id = .MinusPercent;
                 },
             }
         }
 
-        if (result.id == Token.Id.Eof) {
+        if (result.id == .Eof) {
             if (self.pending_invalid_token) |token| {
                 self.pending_invalid_token = null;
                 return token;
@@ -1433,8 +1428,8 @@ pub const Tokenizer = struct {
         if (self.pending_invalid_token != null) return;
         const invalid_length = self.getInvalidCharacterLength();
         if (invalid_length == 0) return;
-        self.pending_invalid_token = Token{
-            .id = Token.Id.Invalid,
+        self.pending_invalid_token = .{
+            .id = .Invalid,
             .start = self.index,
             .end = self.index + invalid_length,
         };
@@ -1479,7 +1474,7 @@ pub const Tokenizer = struct {
 };
 
 test "tokenizer" {
-    testTokenize("test", &[_]Token.Id{Token.Id.Keyword_test});
+    testTokenize("test", &[_]Token.Id{.Keyword_test});
 }
 
 test "tokenizer - unknown length pointer and then c pointer" {
@@ -1487,15 +1482,15 @@ test "tokenizer - unknown length pointer and then c pointer" {
         \\[*]u8
         \\[*c]u8
     , &[_]Token.Id{
-        Token.Id.LBracket,
-        Token.Id.Asterisk,
-        Token.Id.RBracket,
-        Token.Id.Identifier,
-        Token.Id.LBracket,
-        Token.Id.Asterisk,
-        Token.Id.Identifier,
-        Token.Id.RBracket,
-        Token.Id.Identifier,
+        .LBracket,
+        .Asterisk,
+        .RBracket,
+        .Identifier,
+        .LBracket,
+        .Asterisk,
+        .Identifier,
+        .RBracket,
+        .Identifier,
     });
 }
 
@@ -1566,125 +1561,125 @@ test "tokenizer - char literal with unicode code point" {
 
 test "tokenizer - float literal e exponent" {
     testTokenize("a = 4.94065645841246544177e-324;\n", &[_]Token.Id{
-        Token.Id.Identifier,
-        Token.Id.Equal,
-        Token.Id.FloatLiteral,
-        Token.Id.Semicolon,
+        .Identifier,
+        .Equal,
+        .FloatLiteral,
+        .Semicolon,
     });
 }
 
 test "tokenizer - float literal p exponent" {
     testTokenize("a = 0x1.a827999fcef32p+1022;\n", &[_]Token.Id{
-        Token.Id.Identifier,
-        Token.Id.Equal,
-        Token.Id.FloatLiteral,
-        Token.Id.Semicolon,
+        .Identifier,
+        .Equal,
+        .FloatLiteral,
+        .Semicolon,
     });
 }
 
 test "tokenizer - chars" {
-    testTokenize("'c'", &[_]Token.Id{Token.Id.CharLiteral});
+    testTokenize("'c'", &[_]Token.Id{.CharLiteral});
 }
 
 test "tokenizer - invalid token characters" {
-    testTokenize("#", &[_]Token.Id{Token.Id.Invalid});
-    testTokenize("`", &[_]Token.Id{Token.Id.Invalid});
-    testTokenize("'c", &[_]Token.Id{Token.Id.Invalid});
-    testTokenize("'", &[_]Token.Id{Token.Id.Invalid});
-    testTokenize("''", &[_]Token.Id{ Token.Id.Invalid, Token.Id.Invalid });
+    testTokenize("#", &[_]Token.Id{.Invalid});
+    testTokenize("`", &[_]Token.Id{.Invalid});
+    testTokenize("'c", &[_]Token.Id{.Invalid});
+    testTokenize("'", &[_]Token.Id{.Invalid});
+    testTokenize("''", &[_]Token.Id{ .Invalid, .Invalid });
 }
 
 test "tokenizer - invalid literal/comment characters" {
     testTokenize("\"\x00\"", &[_]Token.Id{
-        Token.Id.StringLiteral,
-        Token.Id.Invalid,
+        .StringLiteral,
+        .Invalid,
     });
     testTokenize("//\x00", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\x1f", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\x7f", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
 }
 
 test "tokenizer - utf8" {
-    testTokenize("//\xc2\x80", &[_]Token.Id{Token.Id.LineComment});
-    testTokenize("//\xf4\x8f\xbf\xbf", &[_]Token.Id{Token.Id.LineComment});
+    testTokenize("//\xc2\x80", &[_]Token.Id{.LineComment});
+    testTokenize("//\xf4\x8f\xbf\xbf", &[_]Token.Id{.LineComment});
 }
 
 test "tokenizer - invalid utf8" {
     testTokenize("//\x80", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\xbf", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\xf8", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\xff", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\xc2\xc0", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\xe0", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\xf0", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\xf0\x90\x80\xc0", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
 }
 
 test "tokenizer - illegal unicode codepoints" {
     // unicode newline characters.U+0085, U+2028, U+2029
-    testTokenize("//\xc2\x84", &[_]Token.Id{Token.Id.LineComment});
+    testTokenize("//\xc2\x84", &[_]Token.Id{.LineComment});
     testTokenize("//\xc2\x85", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
-    testTokenize("//\xc2\x86", &[_]Token.Id{Token.Id.LineComment});
-    testTokenize("//\xe2\x80\xa7", &[_]Token.Id{Token.Id.LineComment});
+    testTokenize("//\xc2\x86", &[_]Token.Id{.LineComment});
+    testTokenize("//\xe2\x80\xa7", &[_]Token.Id{.LineComment});
     testTokenize("//\xe2\x80\xa8", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
     testTokenize("//\xe2\x80\xa9", &[_]Token.Id{
-        Token.Id.LineComment,
-        Token.Id.Invalid,
+        .LineComment,
+        .Invalid,
     });
-    testTokenize("//\xe2\x80\xaa", &[_]Token.Id{Token.Id.LineComment});
+    testTokenize("//\xe2\x80\xaa", &[_]Token.Id{.LineComment});
 }
 
 test "tokenizer - string identifier and builtin fns" {
     testTokenize(
         \\const @"if" = @import("std");
     , &[_]Token.Id{
-        Token.Id.Keyword_const,
-        Token.Id.Identifier,
-        Token.Id.Equal,
-        Token.Id.Builtin,
-        Token.Id.LParen,
-        Token.Id.StringLiteral,
-        Token.Id.RParen,
-        Token.Id.Semicolon,
+        .Keyword_const,
+        .Identifier,
+        .Equal,
+        .Builtin,
+        .LParen,
+        .StringLiteral,
+        .RParen,
+        .Semicolon,
     });
 }
 
@@ -1692,26 +1687,26 @@ test "tokenizer - multiline string literal with literal tab" {
     testTokenize(
         \\\\foo	bar
     , &[_]Token.Id{
-        Token.Id.MultilineStringLiteralLine,
+        .MultilineStringLiteralLine,
     });
 }
 
 test "tokenizer - pipe and then invalid" {
     testTokenize("||=", &[_]Token.Id{
-        Token.Id.PipePipe,
-        Token.Id.Equal,
+        .PipePipe,
+        .Equal,
     });
 }
 
 test "tokenizer - line comment and doc comment" {
-    testTokenize("//", &[_]Token.Id{Token.Id.LineComment});
-    testTokenize("// a / b", &[_]Token.Id{Token.Id.LineComment});
-    testTokenize("// /", &[_]Token.Id{Token.Id.LineComment});
-    testTokenize("/// a", &[_]Token.Id{Token.Id.DocComment});
-    testTokenize("///", &[_]Token.Id{Token.Id.DocComment});
-    testTokenize("////", &[_]Token.Id{Token.Id.LineComment});
-    testTokenize("//!", &[_]Token.Id{Token.Id.ContainerDocComment});
-    testTokenize("//!!", &[_]Token.Id{Token.Id.ContainerDocComment});
+    testTokenize("//", &[_]Token.Id{.LineComment});
+    testTokenize("// a / b", &[_]Token.Id{.LineComment});
+    testTokenize("// /", &[_]Token.Id{.LineComment});
+    testTokenize("/// a", &[_]Token.Id{.DocComment});
+    testTokenize("///", &[_]Token.Id{.DocComment});
+    testTokenize("////", &[_]Token.Id{.LineComment});
+    testTokenize("//!", &[_]Token.Id{.ContainerDocComment});
+    testTokenize("//!!", &[_]Token.Id{.ContainerDocComment});
 }
 
 test "tokenizer - line comment followed by identifier" {
@@ -1720,28 +1715,28 @@ test "tokenizer - line comment followed by identifier" {
         \\    // another
         \\    Another,
     , &[_]Token.Id{
-        Token.Id.Identifier,
-        Token.Id.Comma,
-        Token.Id.LineComment,
-        Token.Id.Identifier,
-        Token.Id.Comma,
+        .Identifier,
+        .Comma,
+        .LineComment,
+        .Identifier,
+        .Comma,
     });
 }
 
 test "tokenizer - UTF-8 BOM is recognized and skipped" {
     testTokenize("\xEF\xBB\xBFa;\n", &[_]Token.Id{
-        Token.Id.Identifier,
-        Token.Id.Semicolon,
+        .Identifier,
+        .Semicolon,
     });
 }
 
 test "correctly parse pointer assignment" {
     testTokenize("b.*=3;\n", &[_]Token.Id{
-        Token.Id.Identifier,
-        Token.Id.PeriodAsterisk,
-        Token.Id.Equal,
-        Token.Id.IntegerLiteral,
-        Token.Id.Semicolon,
+        .Identifier,
+        .PeriodAsterisk,
+        .Equal,
+        .IntegerLiteral,
+        .Semicolon,
     });
 }
 
@@ -1984,5 +1979,5 @@ fn testTokenize(source: []const u8, expected_tokens: []const Token.Id) void {
         }
     }
     const last_token = tokenizer.next();
-    std.testing.expect(last_token.id == Token.Id.Eof);
+    std.testing.expect(last_token.id == .Eof);
 }