[llvm] 9a84c62 - [cmake] Don't generate per-file "__SHORT_FILE__" defines on visual studio builds (#151167)

[via llvm-commits]

Author: Simon Pilgrim
Date: 2025-07-30T17:10:23+01:00
New Revision: 9a84c62da4e8bcf76c39077e0c18f21dd724e9ab

URL: https://github.com/llvm/llvm-project/commit/9a84c62da4e8bcf76c39077e0c18f21dd724e9ab
DIFF: https://github.com/llvm/llvm-project/commit/9a84c62da4e8bcf76c39077e0c18f21dd724e9ab.diff

LOG: [cmake] Don't generate per-file "__SHORT_FILE__" defines on visual studio builds (#151167)

As reported on #150677 - this is preventing msbuild parallelization as cmake is repeatedly being updated

Added: 
    

Modified: 
    llvm/cmake/modules/LLVMProcessSources.cmake

Removed: 
    


################################################################################
diff  --git a/llvm/cmake/modules/LLVMProcessSources.cmake b/llvm/cmake/modules/LLVMProcessSources.cmake
index 6282b26bddded..cf358a88f5fb6 100644
--- a/llvm/cmake/modules/LLVMProcessSources.cmake
+++ b/llvm/cmake/modules/LLVMProcessSources.cmake
@@ -58,16 +58,19 @@ function(llvm_process_sources OUT_VAR)
   set(sources ${ARG_UNPARSED_ARGUMENTS})
   llvm_check_source_file_list(${sources})
 
-  foreach(fn ${sources})
-    get_filename_component(suf ${fn} EXT)
-    if("${suf}" STREQUAL ".cpp" OR "${suf}" STREQUAL ".c")
-      get_filename_component(short_name ${fn} NAME)
-      set_property(
-          SOURCE ${fn}
-          APPEND
-          PROPERTY COMPILE_DEFINITIONS __SHORT_FILE__="${short_name}")
-    endif()
-  endforeach()
+  # Don't generate __SHORT_FILE__ on VS builds as it can prevent build parallelisation.
+  if(NOT CMAKE_GENERATOR MATCHES "Visual Studio")
+    foreach(fn ${sources})
+      get_filename_component(suf ${fn} EXT)
+      if("${suf}" STREQUAL ".cpp" OR "${suf}" STREQUAL ".c")
+        get_filename_component(short_name ${fn} NAME)
+        set_property(
+            SOURCE ${fn}
+            APPEND
+            PROPERTY COMPILE_DEFINITIONS __SHORT_FILE__="${short_name}")
+      endif()
+    endforeach()
+  endif()
 
 
   # This adds .td and .h files to the Visual Studio solution: