[llvm-branch-commits] [llvm] f004359 - [windows] Add /Gw to compiler flags

[Hans Wennborg via llvm-branch-commits]

Author: Nico Weber
Date: 2020-02-20T08:50:54+01:00
New Revision: f004359106cfda578733dff1380560b68f9c3713

URL: https://github.com/llvm/llvm-project/commit/f004359106cfda578733dff1380560b68f9c3713
DIFF: https://github.com/llvm/llvm-project/commit/f004359106cfda578733dff1380560b68f9c3713.diff

LOG: [windows] Add /Gw to compiler flags

This is like -fdata-sections, and it's not part of /O2 by default for some reason.

In the cmake build, reduces the size of clang.exe from 70,358,016 bytes to 69,982,720 bytes.

clang-format.exe goes from 3,703,296 bytes to 3,331,072 bytes.

Differential Revision: https://reviews.llvm.org/D74573

(cherry picked from commit 09153ab9d267a86d6e9bce18d5074617de5879a5)

Added: 
    

Modified: 
    llvm/cmake/modules/HandleLLVMOptions.cmake
    llvm/utils/gn/build/BUILD.gn

Removed: 
    


################################################################################
diff  --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index ab219e52f9d9..30f04ca34c2c 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -788,6 +788,10 @@ if(NOT CYGWIN AND NOT WIN32)
     endif()
     add_flag_if_supported("-fdata-sections" FDATA_SECTIONS)
   endif()
+elseif(MSVC)
+  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+    append("/Gw" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+  endif()
 endif()
 
 if(MSVC)

diff  --git a/llvm/utils/gn/build/BUILD.gn b/llvm/utils/gn/build/BUILD.gn
index b06ef9ad83e3..b74268996f15 100644
--- a/llvm/utils/gn/build/BUILD.gn
+++ b/llvm/utils/gn/build/BUILD.gn
@@ -60,6 +60,7 @@ config("compiler_defaults") {
     if (is_optimized) {
       cflags += [
         "/O2",
+        "/Gw",
         "/Zc:inline",
       ]
       ldflags += [