Upgrade Zig toolchain to 0.15.2

toolchain/defs.bzl

@@ -153,11 +153,14 @@ def _zig_repository_impl(repository_ctx):
         "_ext": zig_ext,
         "version": repository_ctx.attr.version,
         "host_platform": host_platform,
+        # Zig >=0.14.1 tarballs are named zig-{arch}-{os}-{version}.
+        "zig_platform": "{}-{}".format(host_arch, host_os),
     }
     format_vars_exec = {
         "_ext": repository_ctx.attr.host_platform_ext[exec_platform],
         "version": repository_ctx.attr.version,
         "host_platform": exec_platform,
+        "zig_platform": "{}-{}".format(exec_arch, exec_os),
     }
 
     for dest, src in {
@@ -179,7 +182,7 @@ def _zig_repository_impl(repository_ctx):
     repository_ctx.download_and_extract(
         auth = use_netrc(read_user_netrc(repository_ctx), urls, {}),
         url = urls,
-        stripPrefix = "zig-{host_platform}-{version}/".format(**format_vars),
+        stripPrefix = "zig-{zig_platform}-{version}/".format(**format_vars),
         sha256 = zig_sha256,
     )
 
@@ -267,7 +270,7 @@ def _zig_repository_impl(repository_ctx):
     repository_ctx.download_and_extract(
         auth = use_netrc(read_user_netrc(repository_ctx), urls, {}),
         url = urls,
-        stripPrefix = "zig-{host_platform}-{version}/".format(**format_vars_exec),
+        stripPrefix = "zig-{zig_platform}-{version}/".format(**format_vars_exec),
         sha256 = repository_ctx.attr.host_platform_sha256[exec_platform],
     )
 
@@ -345,7 +348,11 @@ def declare_files(os):
                 "lib/libunwind/**",
                 "lib/compiler_rt/**",
                 "lib/std/**",
-                "lib/tsan/**",
+                # Zig 0.15 renamed lib/tsan to lib/libtsan.
+                "lib/libtsan/**",
+                # Zig 0.15's lib/c.zig (the libzigc shim built during linking)
+                # imports lib/c/*.zig, which must be staged into the sandbox.
+                "lib/c/**",
                 "lib/*.zig",
                 "lib/*.h",
             ]),

toolchain/private/defs.bzl

@@ -154,12 +154,15 @@ def _target_linux_gnu(gocpu, zigcpu, glibc_version):
         gotarget = "linux_{}_{}".format(gocpu, glibc_suffix),
         zigtarget = "{}-linux-{}".format(zigcpu, glibc_suffix),
         includes = [
-                       "libc/include/{}-linux-gnu".format(zigcpu),
                        "libc/include/generic-glibc",
                    ] +
-                   # x86_64-linux-any is x86_64-linux and x86-linux combined.
-                   (["libc/include/x86-linux-any"] if zigcpu == "x86_64" else []) +
-                   (["libc/include/{}-linux-any".format(zigcpu)] if zigcpu != "x86_64" else []) + [
+                   # Zig 0.15 folded x86_64-linux-gnu into the shared
+                   # x86-linux-gnu dir. x86_64-linux-any never existed and is
+                   # likewise covered by x86-linux-any.
+                   (["libc/include/x86-linux-gnu", "libc/include/x86-linux-any"] if zigcpu == "x86_64" else [
+                       "libc/include/{}-linux-gnu".format(zigcpu),
+                       "libc/include/{}-linux-any".format(zigcpu),
+                   ]) + [
             "libc/include/any-linux-any",
         ] + _INCLUDE_TAIL,
         linkopts = [],

toolchain/private/zig_sdk.bzl

@@ -1,17 +1,23 @@
-VERSION = "0.14.0"
+VERSION = "0.15.2"
 
 HOST_PLATFORM_SHA256 = {
-    "linux-aarch64": "ab64e3ea277f6fc5f3d723dcd95d9ce1ab282c8ed0f431b4de880d30df891e4f",
-    "linux-x86_64": "473ec26806133cf4d1918caf1a410f8403a13d979726a9045b421b685031a982",
-    "macos-aarch64": "b71e4b7c4b4be9953657877f7f9e6f7ee89114c716da7c070f4a238220e95d7e",
-    "macos-x86_64": "685816166f21f0b8d6fc7aa6a36e91396dcd82ca6556dfbe3e329deffc01fec3",
-    "windows-aarch64": "03e984383ebb8f85293557cfa9f48ee8698e7c400239570c9ff1aef3bffaf046",
-    "windows-x86_64": "f53e5f9011ba20bbc3e0e6d0a9441b31eb227a97bac0e7d24172f1b8b27b4371",
+    "linux-aarch64": "958ed7d1e00d0ea76590d27666efbf7a932281b3d7ba0c6b01b0ff26498f667f",
+    "linux-x86_64": "02aa270f183da276e5b5920b1dac44a63f1a49e55050ebde3aecc9eb82f93239",
+    "macos-aarch64": "3cc2bab367e185cdfb27501c4b30b1b0653c28d9f73df8dc91488e66ece5fa6b",
+    "macos-x86_64": "375b6909fc1495d16fc2c7db9538f707456bfc3373b14ee83fdd3e22b3d43f7f",
+    "windows-aarch64": "b926465f8872bf983422257cd9ec248bb2b270996fbe8d57872cca13b56fc370",
+    "windows-x86_64": "3a0ed1e8799a2f8ce2a6e6290a9ff22e6906f8227865911fb7ddedc3cc14cb0c",
 }
 
+# Zig >=0.14.1 names its release tarballs zig-{arch}-{os}-{version} (arch
+# first), whereas older releases used zig-{os}-{arch}-{version}. The download
+# URL and archive strip-prefix therefore use the {zig_platform} format var
+# (arch-os), while the dicts above stay keyed by {os}-{arch} for the public
+# host_platform_sha256 / host_platform_ext override API.
+
 # Official recommended version. Should use this when we have a usable release.
-URL_FORMAT_RELEASE = "https://ziglang.org/download/{version}/zig-{host_platform}-{version}.{_ext}"
+URL_FORMAT_RELEASE = "https://ziglang.org/download/{version}/zig-{zig_platform}-{version}.{_ext}"
 
 # Caution: nightly releases are purged from ziglang.org after ~90 days. Use the
 # Bazel mirror or your own.
-URL_FORMAT_NIGHTLY = "https://ziglang.org/builds/zig-{host_platform}-{version}.{_ext}"
+URL_FORMAT_NIGHTLY = "https://ziglang.org/builds/zig-{zig_platform}-{version}.{_ext}"

toolchain/zig-wrapper.zig

@@ -258,6 +258,14 @@ fn parseArgs(
         .arg1, .cc => try args.appendSlice(arena, &[_][]const u8{arg0_noexe}),
     }
 
+    // Zig 0.15 compiles C/C++ with UBSan instrumentation by default, which
+    // surfaces as `ld.lld: error: undefined symbol: __ubsan_handle_*` when
+    // the instrumented objects are linked. Disable it by default; the flag
+    // is added before the caller's args, so an explicit -fsanitize=undefined
+    // from the caller still takes precedence.
+    if (run_mode == RunMode.cc)
+        try args.appendSlice(arena, &[_][]const u8{"-fno-sanitize=undefined"});
+
     // Process arguments, transforming -u SYMBOL into -Wl,-u,SYMBOL
     // This is needed because zig c++ doesn't handle the -u flag correctly
     // (it tries to open the symbol name as a file instead of passing it to the linker)
@@ -454,6 +462,7 @@ test "zig-wrapper:parseArgs" {
                         "tools" ++ sep ++ "x86_64-linux-musl" ++ sep ++
                             ".." ++ sep ++ ".." ++ sep ++ "zig" ++ EXE,
                         "c++",
+                        "-fno-sanitize=undefined",
                         "main.c",
                         "-o",
                         "/dev/null",
@@ -498,6 +507,7 @@ test "zig-wrapper:parseArgs" {
                     .args = &[_][:0]const u8{
                         "external" ++ sep ++ "zig_sdk" ++ sep ++ "zig" ++ EXE,
                         "c++",
+                        "-fno-sanitize=undefined",
                         "main.c",
                         "-o",
                         "/dev/null",

toolchain/zig_cc_toolchain.bzl

@@ -50,7 +50,12 @@ def _compilation_mode_features(ctx):
                 actions = actions,
                 flag_groups = [
                     flag_group(
-                        flags = ["-g", "-fsanitize-undefined-strip-path-components=-1"],
+                        # -fno-sanitize=undefined: Zig 0.15 enables UBSan for
+                        # C/C++ by default, which leads to `undefined symbol:
+                        # __ubsan_handle_*` link errors. The wrapper also
+                        # passes this flag; it is repeated here so the intent
+                        # is visible in the toolchain config.
+                        flags = ["-g", "-fsanitize-undefined-strip-path-components=-1", "-fno-sanitize=undefined"],
                     ),
                 ],
             ),
@@ -79,7 +84,8 @@ def _compilation_mode_features(ctx):
                 actions = actions,
                 flag_groups = [
                     flag_group(
-                        flags = ["-fno-lto", "-fsanitize-undefined-strip-path-components=-1"],
+                        # -fno-sanitize=undefined: see the dbg feature above.
+                        flags = ["-fno-lto", "-fsanitize-undefined-strip-path-components=-1", "-fno-sanitize=undefined"],
                     ),
                 ],
             ),