[llvm] 1839b75 - [runtimes] Skip custom linker validation for gpu/offload targets (#189933)

[via llvm-commits]

Author: Wenju He
Date: 2026-04-06T07:18:36+08:00
New Revision: 1839b755ddf0993ab1fd962028b21986097e3ccd

URL: https://github.com/llvm/llvm-project/commit/1839b755ddf0993ab1fd962028b21986097e3ccd
DIFF: https://github.com/llvm/llvm-project/commit/1839b755ddf0993ab1fd962028b21986097e3ccd.diff

LOG: [runtimes] Skip custom linker validation for gpu/offload targets (#189933)

This fixes `Host compiler does not support '-fuse-ld=lld'` error when
cross-build libclc for gpu target. Cmake configure command is:
-DRUNTIMES_amdgcn-amd-amdhsa-llvm_LLVM_ENABLE_RUNTIMES=libclc \
-DLLVM_RUNTIME_TARGETS="amdgcn-amd-amdhsa-llvm"
libclc targets only support offload target cross-build and can't link
host executable. The configuration error is false positive for offload.

This PR adds a baseline test to first check if the target can link
executable. If it fails (typical for gpu/offload), we skip the custom
linker validation.

Added: 
    

Modified: 
    llvm/cmake/modules/HandleLLVMOptions.cmake

Removed: 
    


################################################################################
diff  --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index f645de1277687..5f1d68762c038 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -429,14 +429,20 @@ if( LLVM_ENABLE_LLD )
 endif()
 
 if( LLVM_USE_LINKER )
+  check_cxx_source_compiles("int main() { return 0; }" _CAN_LINK_EXECUTABLE)
+  mark_as_advanced(_CAN_LINK_EXECUTABLE)
   append("-fuse-ld=${LLVM_USE_LINKER}"
     CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
-  check_cxx_source_compiles("int main() { return 0; }" CXX_SUPPORTS_CUSTOM_LINKER)
-  if ( NOT CXX_SUPPORTS_CUSTOM_LINKER )
-    message(FATAL_ERROR "Host compiler does not support '-fuse-ld=${LLVM_USE_LINKER}'. "
-                        "Please make sure that '${LLVM_USE_LINKER}' is installed and "
-                        "that your host compiler can compile a simple program when "
-                        "given the option '-fuse-ld=${LLVM_USE_LINKER}'.")
+  if(_CAN_LINK_EXECUTABLE)
+    check_cxx_source_compiles("int main() { return 0; }" CXX_SUPPORTS_CUSTOM_LINKER)
+    if ( NOT CXX_SUPPORTS_CUSTOM_LINKER )
+      message(FATAL_ERROR "Host compiler does not support '-fuse-ld=${LLVM_USE_LINKER}'. "
+                          "Please make sure that '${LLVM_USE_LINKER}' is installed and "
+                          "that your host compiler can compile a simple program when "
+                          "given the option '-fuse-ld=${LLVM_USE_LINKER}'.")
+    endif()
+  else()
+    message(STATUS "Skipping custom linker check: offload target cannot link executable")
   endif()
 endif()