test: add a standalone test for compiling tsan

test/standalone/build.zig.zon

@@ -208,6 +208,9 @@
         .run_cwd = .{
             .path = "run_cwd",
         },
+        .tsan = .{
+            .path = "tsan",
+        },
     },
     .paths = .{
         "build.zig",

test/standalone/tsan/build.zig

@@ -0,0 +1,59 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) !void {
+    const test_step = b.step("test", "Test the program");
+    b.default_step = test_step;
+
+    const is_macos = b.graph.host.result.os.tag == .macos;
+
+    for ([_]struct { std.Target.Os.Tag, []const std.Target.Cpu.Arch }{
+        // .s390x and mips64(el) fail to build
+        .{ .linux, &.{ .aarch64, .aarch64_be, .loongarch64, .powerpc64, .powerpc64le, .riscv64, .x86_64 } },
+        .{ .macos, &.{ .x86_64, .aarch64 } },
+
+        // Missing system headers
+        // https://github.com/ziglang/zig/issues/24736
+        // .{ .freebsd, &.{ .aarch64, .powerpc64, .powerpc64le, .riscv64, .x86_64 } },
+        // https://github.com/ziglang/zig/issues/24737
+        // .{ .netbsd, &.{ .aarch64, .aarch64_be, .x86_64 } },
+
+        // TSan doesn't have full support for windows yet.
+        // .{ .windows, &.{ .aarch64, .x86_64 } },
+    }) |entry| {
+        switch (entry[0]) {
+            // compiling tsan on macos requires system headers that aren't present during cross-compilation
+            .macos => {
+                if (!is_macos) continue;
+                const target = b.resolveTargetQuery(.{});
+                const exe = b.addExecutable(.{
+                    .name = b.fmt("tsan_{s}_{s}", .{ @tagName(entry[0]), @tagName(target.result.cpu.arch) }),
+                    .root_module = b.createModule(.{
+                        .root_source_file = b.path("main.zig"),
+                        .target = target,
+                        .optimize = .Debug,
+                        .sanitize_thread = true,
+                    }),
+                });
+                const install_exe = b.addInstallArtifact(exe, .{});
+                test_step.dependOn(&install_exe.step);
+            },
+            else => for (entry[1]) |arch| {
+                const target = b.resolveTargetQuery(.{
+                    .os_tag = entry[0],
+                    .cpu_arch = arch,
+                });
+                const exe = b.addExecutable(.{
+                    .name = b.fmt("tsan_{s}_{s}", .{ @tagName(entry[0]), @tagName(arch) }),
+                    .root_module = b.createModule(.{
+                        .root_source_file = b.path("main.zig"),
+                        .target = target,
+                        .optimize = .Debug,
+                        .sanitize_thread = true,
+                    }),
+                });
+                const install_exe = b.addInstallArtifact(exe, .{});
+                test_step.dependOn(&install_exe.step);
+            },
+        }
+    }
+}

test/standalone/tsan/main.zig

@@ -0,0 +1,3 @@
+const std = @import("std");
+
+pub fn main() !void {}