Fix ml path for Windows clang-cl cc toolchain

Assembly files are not valid inputs for `clang-cl.exe`; the MSVC `ml64.exe` must be used instead. Fixes #23128. Closes #23337. PiperOrigin-RevId: 666406544 Change-Id: Ia7a5fc4702f08a5754145ca286c079d1a4f0e204
bazelbuild · Aug 22, 2024 · bbc4e22 · bbc4e22
1 parent 048f843
commit bbc4e22
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Showing 2 changed files with 57 additions and 21 deletions.
diff --git a/src/test/py/bazel/bazel_windows_cpp_test.py b/src/test/py/bazel/bazel_windows_cpp_test.py
@@ -775,30 +775,65 @@ def testBuildWithClangClByToolchainResolution(self):
         '  "@local_config_cc//:cc-toolchain-x64_windows-clang-cl",',
         ')',
     ])
-    self.ScratchFile('BUILD', [
-        'platform(',
-        '  name = "windows_clang",',
-        '  constraint_values = [',
-        '    "@platforms//cpu:x86_64",',
-        '    "@platforms//os:windows",',
-        '    "@bazel_tools//tools/cpp:clang-cl",',
-        '  ]',
-        ')',
-        '',
-        'cc_binary(',
-        '  name = "main",',
-        '  srcs = ["main.cc"],',
-        ')',
-    ])
-    self.ScratchFile('main.cc', [
-        'int main() {',
-        '  return 0;',
-        '}',
-    ])
     exit_code, _, stderr = self.RunBazel([
         'build', '-s', '--incompatible_enable_cc_toolchain_resolution=true',
         '//:main'
     ])
+    self.ScratchFile(
+        'BUILD',
+        [
+            'platform(',
+            '  name = "windows_clang",',
+            '  constraint_values = [',
+            '    "@platforms//cpu:x86_64",',
+            '    "@platforms//os:windows",',
+            '    "@bazel_tools//tools/cpp:clang-cl",',
+            '  ]',
+            ')',
+            '',
+            'cc_binary(',
+            '  name = "main",',
+            '  srcs = [    "main.cc",',
+            '    "inc.asm",',  # Test assemble action_config
+            '    "dec.S",',  # Test preprocess-assemble action_config
+            '  ],',
+            ')',
+        ],
+    )
+    self.ScratchFile(
+        'main.cc',
+        [
+            'int main() {',
+            '  return 0;',
+            '}',
+        ],
+    )
+    self.ScratchFile(
+        'inc.asm',
+        [
+            '.code',
+            'PUBLIC increment',
+            'increment PROC x:WORD',
+            '  xchg rcx,rax',
+            '  inc rax',
+            '  ret',
+            'increment EndP',
+            'END',
+        ],
+    )
+    self.ScratchFile(
+        'dec.S',
+        [
+            '.code',
+            'PUBLIC decrement',
+            'decrement PROC x:WORD',
+            '  xchg rcx,rax',
+            '  dec rax',
+            '  ret',
+            'decrement EndP',
+            'END',
+        ],
+    )
     self.AssertExitCode(exit_code, 0, stderr)
     self.assertIn('clang-cl.exe', ''.join(stderr))
 

diff --git a/tools/cpp/windows_cc_configure.bzl b/tools/cpp/windows_cc_configure.bzl
@@ -793,7 +793,8 @@ def _get_clang_cl_vars(repository_ctx, paths, msvc_vars, target_arch):
         "%{clang_cl_cl_path_" + target_arch + "}": clang_cl_path,
         "%{clang_cl_link_path_" + target_arch + "}": lld_link_path,
         "%{clang_cl_lib_path_" + target_arch + "}": llvm_lib_path,
-        "%{clang_cl_ml_path_" + target_arch + "}": clang_cl_path,
+        # clang-cl does not support assembly files as input.
+        "%{clang_cl_ml_path_" + target_arch + "}": msvc_vars["%{msvc_ml_path_" + target_arch + "}"],
         # LLVM's lld-link.exe doesn't support /DEBUG:FASTLINK.
         "%{clang_cl_dbg_mode_debug_flag_" + target_arch + "}": "/DEBUG",
         "%{clang_cl_fastbuild_mode_debug_flag_" + target_arch + "}": "/DEBUG",