Make `@typeInfo` return null-terminated strings

Changes the types of `std.builtin.Type` `name` fields from `[]const u8`
to `[:0]const u8`, which should make them easier to pass to C APIs
expecting null-terminated strings.

This will break code that reifies types using `[]const u8` strings, such
as code that uses `std.mem.tokenize()` to construct types from strings
at comptime. Luckily, the fix is simple: simply concatenate the
`[]const u8` string with an empty string literal (`name ++ ""`) to
explicitly coerce it to `[:0]const u8`.

Co-authored-by: Krzysztof Wolicki <der.teufel.mail@gmail.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/std/builtin.zig b/lib/std/builtin.zig
index 19c704c9a5..24c6036d60 100644
--- a/lib/std/builtin.zig
+++ b/lib/std/builtin.zig
@@ -314,7 +314,7 @@ pub const Type = union(enum) {
     /// This data structure is used by the Zig language code generation and
     /// therefore must be kept in sync with the compiler implementation.
     pub const StructField = struct {
-        name: []const u8,
+        name: [:0]const u8,
         type: type,
         default_value: ?*const anyopaque,
         is_comptime: bool,
@@ -348,7 +348,7 @@ pub const Type = union(enum) {
     /// This data structure is used by the Zig language code generation and
     /// therefore must be kept in sync with the compiler implementation.
     pub const Error = struct {
-        name: []const u8,
+        name: [:0]const u8,
     };
 
     /// This data structure is used by the Zig language code generation and
@@ -358,7 +358,7 @@ pub const Type = union(enum) {
     /// This data structure is used by the Zig language code generation and
     /// therefore must be kept in sync with the compiler implementation.
     pub const EnumField = struct {
-        name: []const u8,
+        name: [:0]const u8,
         value: comptime_int,
     };
 
@@ -374,7 +374,7 @@ pub const Type = union(enum) {
     /// This data structure is used by the Zig language code generation and
     /// therefore must be kept in sync with the compiler implementation.
     pub const UnionField = struct {
-        name: []const u8,
+        name: [:0]const u8,
         type: type,
         alignment: comptime_int,
     };
@@ -436,7 +436,7 @@ pub const Type = union(enum) {
     /// This data structure is used by the Zig language code generation and
     /// therefore must be kept in sync with the compiler implementation.
     pub const Declaration = struct {
-        name: []const u8,
+        name: [:0]const u8,
     };
 };