update the stage1 implementation to the new proposal

See #3731

4 files changed, 17 insertions, 7 deletions

diff --git a/lib/std/builtin.zig b/lib/std/builtin.zig
index 56c3426d8b..64fc68e4cc 100644
--- a/lib/std/builtin.zig
+++ b/lib/std/builtin.zig
@@ -144,7 +144,12 @@ pub const TypeInfo = union(enum) {
         alignment: comptime_int,
         child: type,
         is_allowzero: bool,
-        is_null_terminated: bool,
+        /// The type of the sentinel is the element type of the pointer, which is
+        /// the value of the `child` field in this struct. However there is no way
+        /// to refer to that type here, so this is a pointer to an opaque value.
+        /// It will be known at compile-time to be the correct type. Dereferencing
+        /// this pointer will work at compile-time.
+        sentinel: ?*const c_void,
 
         /// This data structure is used by the Zig language code generation and
         /// therefore must be kept in sync with the compiler implementation.
@@ -161,7 +166,12 @@ pub const TypeInfo = union(enum) {
     pub const Array = struct {
         len: comptime_int,
         child: type,
-        is_null_terminated: bool,
+        /// The type of the sentinel is the element type of the array, which is
+        /// the value of the `child` field in this struct. However there is no way
+        /// to refer to that type here, so this is a pointer to an opaque value.
+        /// It will be known at compile-time to be the correct type. Dereferencing
+        /// this pointer will work at compile-time.
+        sentinel: ?*const c_void,
     };
 
     /// This data structure is used by the Zig language code generation and
diff --git a/lib/std/c.zig b/lib/std/c.zig
index 1faf45a489..fac13efc69 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -63,7 +63,7 @@ pub extern "c" fn fclose(stream: *FILE) c_int;
 pub extern "c" fn fwrite(ptr: [*]const u8, size_of_type: usize, item_count: usize, stream: *FILE) usize;
 pub extern "c" fn fread(ptr: [*]u8, size_of_type: usize, item_count: usize, stream: *FILE) usize;
 
-pub extern "c" fn printf(format: [*]null const u8, ...) c_int;
+pub extern "c" fn printf(format: [*:0]const u8, ...) c_int;
 pub extern "c" fn abort() noreturn;
 pub extern "c" fn exit(code: c_int) noreturn;
 pub extern "c" fn isatty(fd: fd_t) c_int;
diff --git a/lib/std/mem.zig b/lib/std/mem.zig
index 160b8e6e5e..f790dd683b 100644
--- a/lib/std/mem.zig
+++ b/lib/std/mem.zig
@@ -1409,7 +1409,7 @@ fn BytesAsValueReturnType(comptime T: type, comptime B: type) type {
     const size = @as(usize, @sizeOf(T));
 
     if (comptime !trait.is(builtin.TypeId.Pointer)(B) or
-        (meta.Child(B) != [size]u8 and meta.Child(B) != [size]null u8))
+        (meta.Child(B) != [size]u8 and meta.Child(B) != [size:0]u8))
     {
         @compileError("expected *[N]u8 " ++ ", passed " ++ @typeName(B));
     }
diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
index ebe396e145..ce19588722 100644
--- a/lib/std/zig/parser_test.zig
+++ b/lib/std/zig/parser_test.zig
@@ -1552,7 +1552,7 @@ test "zig fmt: pointer attributes" {
         \\extern fn f2(s: **align(1) *const *volatile u8) c_int;
         \\extern fn f3(s: *align(1) const *align(1) volatile *const volatile u8) c_int;
         \\extern fn f4(s: *align(1) const volatile u8) c_int;
-        \\extern fn f5(s: [*]null align(1) const volatile u8) c_int;
+        \\extern fn f5(s: [*:0]align(1) const volatile u8) c_int;
         \\
     );
 }
@@ -1563,7 +1563,7 @@ test "zig fmt: slice attributes" {
         \\extern fn f2(s: **align(1) *const *volatile u8) c_int;
         \\extern fn f3(s: *align(1) const *align(1) volatile *const volatile u8) c_int;
         \\extern fn f4(s: *align(1) const volatile u8) c_int;
-        \\extern fn f5(s: [*]null align(1) const volatile u8) c_int;
+        \\extern fn f5(s: [*:0]align(1) const volatile u8) c_int;
         \\
     );
 }
@@ -1885,7 +1885,7 @@ test "zig fmt: arrays" {
         \\        2,
         \\    };
         \\    const a: [0]u8 = []u8{};
-        \\    const x: [4]null u8 = undefined;
+        \\    const x: [4:0]u8 = undefined;
         \\}
         \\
     );