[compiler-rt] 77b7183 - [Runtimes] Fix /clang: prefix warning for GNU-like clang on Windows (#192041)

[via llvm-commits]

Author: Wenju He
Date: 2026-05-08T15:31:57+08:00
New Revision: 77b7183542f7f6b3b47a271324c2ac93feb8f811

URL: https://github.com/llvm/llvm-project/commit/77b7183542f7f6b3b47a271324c2ac93feb8f811
DIFF: https://github.com/llvm/llvm-project/commit/77b7183542f7f6b3b47a271324c2ac93feb8f811.diff

LOG: [Runtimes] Fix /clang: prefix warning for GNU-like clang on Windows (#192041)

libclc has configure warning on Windows:
clang: error: no such file or directory:
'/clang:--target=amdgcn-amd-amdhsa-llvm' clang: error: no such file or
directory: '/clang:-print-target-triple'
  CMake Warning at CMakeLists.txt:239 (message):
    Failed to execute `llvm-project/build/bin/clang.exe
/clang:--target=amdgcn-amd-amdhsa-llvm /clang:-print-target-triple` to
    normalize target triple.

Switch to check CMAKE_C_COMPILER_FRONTEND_VARIANT because
- CMAKE_C_SIMULATE_ID=MSVC: true for both clang and clang-cl.
- CMAKE_C_COMPILER_FRONTEND_VARIANT=MSVC: true for clang-cl; false for clang.

Added: 
    

Modified: 
    compiler-rt/cmake/Modules/CompilerRTUtils.cmake
    runtimes/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
index dc9d2f4c473f8..f4e5560f88412 100644
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -392,7 +392,7 @@ macro(construct_compiler_rt_default_triple)
 
   if(CMAKE_C_COMPILER_ID MATCHES "Clang")
     set(option_prefix "")
-    if (CMAKE_C_SIMULATE_ID MATCHES "MSVC")
+    if (CMAKE_C_COMPILER_FRONTEND_VARIANT MATCHES "MSVC")
       set(option_prefix "/clang:")
     endif()
     set(print_target_triple ${CMAKE_C_COMPILER} ${option_prefix}--target=${COMPILER_RT_DEFAULT_TARGET_TRIPLE} ${option_prefix}-print-target-triple)

diff  --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
index 75551ba0c651a..fd4230b15f72e 100644
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -223,7 +223,7 @@ set(LLVM_TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE}")
 
 if(CMAKE_C_COMPILER_ID MATCHES "Clang")
   set(option_prefix "")
-  if (CMAKE_C_SIMULATE_ID MATCHES "MSVC")
+  if (CMAKE_C_COMPILER_FRONTEND_VARIANT MATCHES "MSVC")
     set(option_prefix "/clang:")
   endif()
   set(print_target_triple ${CMAKE_C_COMPILER} ${option_prefix}--target=${LLVM_DEFAULT_TARGET_TRIPLE} ${option_prefix}-print-target-triple)