Generate PDB files for profiling even in Release build

[takuto.ikuta]

Summary

This patch enables PDB generation for Release build, which has slightly different optimize option with RelWithDebInfo on windows.

This helps to know slow part of Release build when profiling.

[zturner]

True, link time would probably be affected. But I think if anyone is concerned about this, they can add -DLLVM_DISABLE_PDB. Having it generate a PDB should be the default IMO.

[takuto.ikuta]

Thanks. Could you merge this patch instead of me? I don't have permission.

[takuto.ikuta]

Ping?

[takuto.ikuta]

Thank you!

[rongjiecomputer]

I don't see LLVM_DISABLE_PDB option being added anywhere, was it accidentally omitted in this patch?

I want to avoid producing .pdb as I have to fit building LLVM under 1 hour due to CI limitation and it already takes 53 minutes without producing .pdb.

[thakis]

llvm/trunk/cmake/modules/HandleLLVMOptions.cmake

359 ↗

(On Diff #133269)

Doesn't /DEBUG disable /OPT:REF and /OPT:ICF by default? I think you probably want "/DEBUG /OPT:REF /OPT:ICF" instead of just "/DEBUG".

llvm/CMakeLists.txt

 
 option(LLVM_FORCE_USE_OLD_HOST_TOOLCHAIN
        "Set to ON to force using an old, unsupported host toolchain." OFF)
 
 option(LLVM_USE_INTEL_JITEVENTS
   "Use Intel JIT API to inform Intel(R) VTune(TM) Amplifier XE 2011 about JIT code"
   OFF)
 
+option(LLVM_ENABLE_PDB "Generate .pdb files for profiling in Release build" OFF)
+
 if( LLVM_USE_INTEL_JITEVENTS )
   # Verify we are on a supported platform
   if( NOT CMAKE_SYSTEM_NAME MATCHES "Windows" AND NOT CMAKE_SYSTEM_NAME MATCHES "Linux" )
     message(FATAL_ERROR
       "Intel JIT API support is available on Linux and Windows only.")
   endif()
 endif( LLVM_USE_INTEL_JITEVENTS )
 
foreach(target ${LLVM_DISTRIBUTION_COMPONENTS})
     endif()
   endforeach()
 endif()
 
 # This allows us to deploy the Universal CRT DLLs by passing -DCMAKE_INSTALL_UCRT_LIBRARIES=ON to CMake
 if (MSVC AND CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
   include(InstallRequiredSystemLibraries)
 endif()
-

llvm/cmake/modules/HandleLLVMOptions.cmake

if( MSVC )
   )
 
   if (LLVM_ENABLE_WERROR)
     append("/WX" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   endif (LLVM_ENABLE_WERROR)
 
   append("/Zc:inline" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 
+  if (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE" AND LLVM_ENABLE_PDB)
+    append("/Zi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+    append("/DEBUG" CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
+  endif (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE" AND LLVM_ENABLE_PDB)
+
   # /Zc:strictStrings is incompatible with VS12's (Visual Studio 2013's)
   # debug mode headers. Instead of only enabling them in VS2013's debug mode,
   # we'll just enable them for Visual Studio 2015 (VS 14, MSVC_VERSION 1900)
   # and up.
   if (NOT (MSVC_VERSION LESS 1900))
     # Disable string literal const->non-const type conversion.
     # "When specified, the compiler requires strict const-qualification
     # conformance for pointers initialized by using string literals."