[compiler-rt] [CMake] Don't use llvm_replace_compiler_option

[mstorsjo]

Summary

Building compiler-rt standalone outside of the main llvm tree is supported. In this case, the llvm cmake modules can be unavailable. (They're generally not needed for plain building the libraries, but are necessary for things like the testsuite. Even if the cmake modules are available, this function is provided by LLVMProcessSources.cmake, which currently isn't being included.)

This fixes building compiler-rt standalone with MSVC/clang-cl, where this cmake command isn't available.

[rnk]

I'd prefer to keep the same /Zi vs. /Z7 setting in the standalone build. Does the standalone build not have access to the installed LLVM cmake modules? If so, I would think we could include them. Or, we could put in a basic regex here like we used to have for -DNDEBUG.

[mstorsjo]

In D58767#1413871, @rnk wrote:

I'd prefer to keep the same /Zi vs. /Z7 setting in the standalone build. Does the standalone build not have access to the installed LLVM cmake modules?

It can be built both with and without the LLVM cmake modules. In this particular case, the cmake modules should have been available though.

If so, I would think we could include them. Or, we could put in a basic regex here like we used to have for -DNDEBUG.

Ok, I'll see if I can find how that was done.

[mstorsjo]

Changed to do the same thing with a regex.

[rnk]

lgtm

CMakeLists.txt

382

I think the indentation here should be two spaces less

CMakeLists.txt

 endif()
 
 # Build sanitizer runtimes with debug info.
 if(MSVC)
   # Use /Z7 instead of /Zi for the asan runtime. This avoids the LNK4099
   # warning from the MS linker complaining that it can't find the 'vc140.pdb'
   # file used by our object library compilations.
   list(APPEND SANITIZER_COMMON_CFLAGS /Z7)
-  llvm_replace_compiler_option(CMAKE_CXX_FLAGS "/Z[i7I]" "/Z7")
-  llvm_replace_compiler_option(CMAKE_CXX_FLAGS_DEBUG "/Z[i7I]" "/Z7")
-  llvm_replace_compiler_option(CMAKE_CXX_FLAGS_RELWITHDEBINFO "/Z[i7I]" "/Z7")
+  foreach(var_to_update
+    CMAKE_CXX_FLAGS
+    CMAKE_CXX_FLAGS_DEBUG
+    CMAKE_CXX_FLAGS_RELWITHDEBINFO)
+    string(REGEX REPLACE "(^| )/Z[i7I]($| )" " /Z7 "
+           "${var_to_update}" "${${var_to_update}}")
+  endforeach()
 elseif(COMPILER_RT_HAS_GLINE_TABLES_ONLY_FLAG AND NOT COMPILER_RT_DEBUG)
   list(APPEND SANITIZER_COMMON_CFLAGS -gline-tables-only)
 elseif(COMPILER_RT_HAS_G_FLAG)
   list(APPEND SANITIZER_COMMON_CFLAGS -g)
 endif()
 
 if(LLVM_ENABLE_MODULES)
   # Sanitizers cannot be built with -fmodules. The interceptors intentionally