(breaking) rework stream abstractions

The main goal here is to make the function pointers comptime, so that we
don't have to do the crazy stuff with async function frames.

Since InStream, OutStream, and SeekableStream are already generic
across error sets, it's not really worse to make them generic across the
vtable as well.

See #764 for the open issue acknowledging that using generics for these
abstractions is a design flaw.

See #130 for the efforts to make these abstractions non-generic.

This commit also changes the OutStream API so that `write` returns
number of bytes written, and `writeAll` is the one that loops until the
whole buffer is written.

3 files changed, 24 insertions, 23 deletions

diff --git a/src-self-hosted/libc_installation.zig b/src-self-hosted/libc_installation.zig
index 41def38126..78aafeff28 100644
--- a/src-self-hosted/libc_installation.zig
+++ b/src-self-hosted/libc_installation.zig
@@ -38,7 +38,7 @@ pub const LibCInstallation = struct {
     pub fn parse(
         allocator: *Allocator,
         libc_file: []const u8,
-        stderr: *std.io.OutStream(fs.File.WriteError),
+        stderr: var,
     ) !LibCInstallation {
         var self: LibCInstallation = .{};
 
@@ -123,7 +123,7 @@ pub const LibCInstallation = struct {
         return self;
     }
 
-    pub fn render(self: LibCInstallation, out: *std.io.OutStream(fs.File.WriteError)) !void {
+    pub fn render(self: LibCInstallation, out: var) !void {
         @setEvalBranchQuota(4000);
         const include_dir = self.include_dir orelse "";
         const sys_include_dir = self.sys_include_dir orelse "";
diff --git a/src-self-hosted/print_targets.zig b/src-self-hosted/print_targets.zig
index bb3841ba24..473e3dfa51 100644
--- a/src-self-hosted/print_targets.zig
+++ b/src-self-hosted/print_targets.zig
@@ -52,7 +52,7 @@ const available_libcs = [_][]const u8{
     "sparc-linux-gnu",
     "sparcv9-linux-gnu",
     "wasm32-freestanding-musl",
-    "x86_64-linux-gnu (native)",
+    "x86_64-linux-gnu",
     "x86_64-linux-gnux32",
     "x86_64-linux-musl",
     "x86_64-windows-gnu",
@@ -61,7 +61,8 @@ const available_libcs = [_][]const u8{
 pub fn cmdTargets(
     allocator: *Allocator,
     args: []const []const u8,
-    stdout: *io.OutStream(fs.File.WriteError),
+    /// Output stream
+    stdout: var,
     native_target: Target,
 ) !void {
     const available_glibcs = blk: {
@@ -92,9 +93,9 @@ pub fn cmdTargets(
     };
     defer allocator.free(available_glibcs);
 
-    const BOS = io.BufferedOutStream(fs.File.WriteError);
-    var bos = BOS.init(stdout);
-    var jws = std.json.WriteStream(BOS.Stream, 6).init(&bos.stream);
+    var bos = io.bufferedOutStream(4096, stdout);
+    const bos_stream = bos.outStream();
+    var jws = std.json.WriteStream(@TypeOf(bos_stream), 6).init(bos_stream);
 
     try jws.beginObject();
 
@@ -219,6 +220,6 @@ pub fn cmdTargets(
 
     try jws.endObject();
 
-    try bos.stream.writeByte('\n');
+    try bos_stream.writeByte('\n');
     return bos.flush();
 }
diff --git a/src-self-hosted/stage2.zig b/src-self-hosted/stage2.zig
index ee6789ab86..8f2656de44 100644
--- a/src-self-hosted/stage2.zig
+++ b/src-self-hosted/stage2.zig
@@ -18,8 +18,8 @@ const assert = std.debug.assert;
 const LibCInstallation = @import("libc_installation.zig").LibCInstallation;
 
 var stderr_file: fs.File = undefined;
-var stderr: *io.OutStream(fs.File.WriteError) = undefined;
-var stdout: *io.OutStream(fs.File.WriteError) = undefined;
+var stderr: fs.File.OutStream = undefined;
+var stdout: fs.File.OutStream = undefined;
 
 comptime {
     _ = @import("dep_tokenizer.zig");
@@ -146,7 +146,7 @@ export fn stage2_free_clang_errors(errors_ptr: [*]translate_c.ClangErrMsg, error
 }
 
 export fn stage2_render_ast(tree: *ast.Tree, output_file: *FILE) Error {
-    const c_out_stream = &std.io.COutStream.init(output_file).stream;
+    const c_out_stream = std.io.cOutStream(output_file);
     _ = std.zig.render(std.heap.c_allocator, c_out_stream, tree) catch |e| switch (e) {
         error.WouldBlock => unreachable, // stage1 opens stuff in exclusively blocking mode
         error.SystemResources => return .SystemResources,
@@ -186,9 +186,9 @@ fn fmtMain(argc: c_int, argv: [*]const [*:0]const u8) !void {
         try args_list.append(mem.toSliceConst(u8, argv[arg_i]));
     }
 
-    stdout = &std.io.getStdOut().outStream().stream;
+    stdout = std.io.getStdOut().outStream();
     stderr_file = std.io.getStdErr();
-    stderr = &stderr_file.outStream().stream;
+    stderr = stderr_file.outStream();
 
     const args = args_list.toSliceConst()[2..];
 
@@ -203,11 +203,11 @@ fn fmtMain(argc: c_int, argv: [*]const [*:0]const u8) !void {
             const arg = args[i];
             if (mem.startsWith(u8, arg, "-")) {
                 if (mem.eql(u8, arg, "--help")) {
-                    try stdout.write(self_hosted_main.usage_fmt);
+                    try stdout.writeAll(self_hosted_main.usage_fmt);
                     process.exit(0);
                 } else if (mem.eql(u8, arg, "--color")) {
                     if (i + 1 >= args.len) {
-                        try stderr.write("expected [auto|on|off] after --color\n");
+                        try stderr.writeAll("expected [auto|on|off] after --color\n");
                         process.exit(1);
                     }
                     i += 1;
@@ -238,14 +238,14 @@ fn fmtMain(argc: c_int, argv: [*]const [*:0]const u8) !void {
 
     if (stdin_flag) {
         if (input_files.len != 0) {
-            try stderr.write("cannot use --stdin with positional arguments\n");
+            try stderr.writeAll("cannot use --stdin with positional arguments\n");
             process.exit(1);
         }
 
         const stdin_file = io.getStdIn();
         var stdin = stdin_file.inStream();
 
-        const source_code = try stdin.stream.readAllAlloc(allocator, self_hosted_main.max_src_size);
+        const source_code = try stdin.readAllAlloc(allocator, self_hosted_main.max_src_size);
         defer allocator.free(source_code);
 
         const tree = std.zig.parse(allocator, source_code) catch |err| {
@@ -272,7 +272,7 @@ fn fmtMain(argc: c_int, argv: [*]const [*:0]const u8) !void {
     }
 
     if (input_files.len == 0) {
-        try stderr.write("expected at least one source file argument\n");
+        try stderr.writeAll("expected at least one source file argument\n");
         process.exit(1);
     }
 
@@ -409,11 +409,11 @@ fn printErrMsgToFile(
     const end_loc = tree.tokenLocationPtr(first_token.end, last_token);
 
     var text_buf = try std.Buffer.initSize(allocator, 0);
-    var out_stream = &std.io.BufferOutStream.init(&text_buf).stream;
+    const out_stream = &text_buf.outStream();
     try parse_error.render(&tree.tokens, out_stream);
     const text = text_buf.toOwnedSlice();
 
-    const stream = &file.outStream().stream;
+    const stream = &file.outStream();
     try stream.print("{}:{}:{}: error: {}\n", .{ path, start_loc.line + 1, start_loc.column + 1, text });
 
     if (!color_on) return;
@@ -641,7 +641,7 @@ fn cmdTargets(zig_triple: [*:0]const u8) !void {
     return @import("print_targets.zig").cmdTargets(
         std.heap.c_allocator,
         &[0][]u8{},
-        &std.io.getStdOut().outStream().stream,
+        std.io.getStdOut().outStream(),
         target,
     );
 }
@@ -808,7 +808,7 @@ const Stage2LibCInstallation = extern struct {
 // ABI warning
 export fn stage2_libc_parse(stage1_libc: *Stage2LibCInstallation, libc_file_z: [*:0]const u8) Error {
     stderr_file = std.io.getStdErr();
-    stderr = &stderr_file.outStream().stream;
+    stderr = stderr_file.outStream();
     const libc_file = mem.toSliceConst(u8, libc_file_z);
     var libc = LibCInstallation.parse(std.heap.c_allocator, libc_file, stderr) catch |err| switch (err) {
         error.ParseError => return .SemanticAnalyzeFail,
@@ -870,7 +870,7 @@ export fn stage2_libc_find_native(stage1_libc: *Stage2LibCInstallation) Error {
 // ABI warning
 export fn stage2_libc_render(stage1_libc: *Stage2LibCInstallation, output_file: *FILE) Error {
     var libc = stage1_libc.toStage2();
-    const c_out_stream = &std.io.COutStream.init(output_file).stream;
+    const c_out_stream = std.io.cOutStream(output_file);
     libc.render(c_out_stream) catch |err| switch (err) {
         error.WouldBlock => unreachable, // stage1 opens stuff in exclusively blocking mode
         error.SystemResources => return .SystemResources,