Commit a0ad2dee6a

@@ -102,7 +102,7 @@ pub fn parse(text: []const u8) !Version {
     if (extra_index == null) return ver;
 
     // Slice optional pre-release or build metadata components.
-    const extra = text[extra_index.?..text.len];
+    const extra: []const u8 = text[extra_index.?..text.len];
     if (extra[0] == '-') {
         const build_index = std.mem.indexOfScalar(u8, extra, '+');
         ver.pre = extra[1..(build_index orelse extra.len)];
@@ -293,3 +293,12 @@ fn testFmt(expected: []const u8, comptime template: []const u8, args: anytype) !
     std.debug.warn("\n======================================\n", .{});
     return error.TestFailed;
 }
+
+test "zig_version" {
+    // An approximate Zig build that predates this test.
+    const older_version = .{ .major = 0, .minor = 8, .patch = 0, .pre = "dev.874" };
+
+    // Simulated compatibility check using Zig version.
+    const compatible = comptime @import("builtin").zig_version.order(older_version) == .gt;
+    if (!compatible) @compileError("zig_version test failed");
+}

@@ -2703,6 +2703,11 @@ pub fn generateBuiltinZigSource(comp: *Compilation, allocator: *Allocator) ![]u8
         \\pub const arch = Target.current.cpu.arch;
         \\/// Deprecated
         \\pub const endian = Target.current.cpu.arch.endian();
+        \\
+        \\/// Zig version. When writing code that supports multiple versions of Zig, prefer
+        \\/// feature detection (i.e. with `@hasDecl` or `@hasField`) over version checks.
+        \\pub const zig_version = try @import("std").SemanticVersion.parse("{s}");
+        \\
         \\pub const output_mode = OutputMode.{};
         \\pub const link_mode = LinkMode.{};
         \\pub const is_test = {};
@@ -2714,6 +2719,7 @@ pub fn generateBuiltinZigSource(comp: *Compilation, allocator: *Allocator) ![]u8
         \\    .features = Target.{}.featureSet(&[_]Target.{}.Feature{{
         \\
     , .{
+        build_options.version,
         std.zig.fmtId(@tagName(comp.bin_file.options.output_mode)),
         std.zig.fmtId(@tagName(comp.bin_file.options.link_mode)),
         comp.bin_file.options.is_test,