From 6e3655db2cc8202424e54bdde83e4240eb680cc3 Mon Sep 17 00:00:00 2001
From: Zsolt Parragi <zsolt.parragi@cancellar.hu>
Date: Mon, 8 Jul 2019 18:52:23 +0200
Subject: Clang: add LTO support for GNU-command line clang on windows

---
 Modules/Platform/Windows-Clang.cmake | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/Modules/Platform/Windows-Clang.cmake b/Modules/Platform/Windows-Clang.cmake
index 728e0b9..6a12381 100644
--- a/Modules/Platform/Windows-Clang.cmake
+++ b/Modules/Platform/Windows-Clang.cmake
@@ -44,15 +44,22 @@ macro(__windows_compiler_clang_gnu lang)
   set(CMAKE_${lang}_USE_RESPONSE_FILE_FOR_LIBRARIES 1)
   set(CMAKE_${lang}_USE_RESPONSE_FILE_FOR_INCLUDES 1)
 
+  set(CMAKE_${lang}_COMPILE_OPTIONS_IPO "-flto")
+  set(_CMAKE_${lang}_IPO_SUPPORTED_BY_CMAKE YES)
+  set(_CMAKE_${lang}_IPO_MAY_BE_SUPPORTED_BY_COMPILER YES)
+  set(CMAKE_${lang}_ARCHIVE_CREATE_IPO "<CMAKE_AR> cr <TARGET> <LINK_FLAGS> <OBJECTS>")
+  set(CMAKE_${lang}_ARCHIVE_APPEND_IPO "<CMAKE_AR> r <TARGET> <LINK_FLAGS> <OBJECTS>")
+  set(CMAKE_${lang}_ARCHIVE_FINISH_IPO "<CMAKE_RANLIB> <TARGET>")
+
   # Create archiving rules to support large object file lists for static libraries.
   set(CMAKE_${lang}_ARCHIVE_CREATE "<CMAKE_AR> qc <TARGET> <LINK_FLAGS> <OBJECTS>")
   set(CMAKE_${lang}_ARCHIVE_APPEND "<CMAKE_AR> q  <TARGET> <LINK_FLAGS> <OBJECTS>")
   set(CMAKE_${lang}_ARCHIVE_FINISH "<CMAKE_RANLIB> <TARGET>")
   set(CMAKE_${lang}_CREATE_SHARED_LIBRARY
-    "<CMAKE_${lang}_COMPILER> -nostartfiles -nostdlib <CMAKE_SHARED_LIBRARY_${lang}_FLAGS> <LANGUAGE_COMPILE_FLAGS> <LINK_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS> -o <TARGET> ${CMAKE_GNULD_IMAGE_VERSION} -Xlinker /implib:<TARGET_IMPLIB> -Xlinker /pdb:<TARGET_PDB> -Xlinker /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR> <OBJECTS> <LINK_LIBRARIES>")
+    "<CMAKE_${lang}_COMPILER> -fuse-ld=lld-link -nostartfiles -nostdlib <CMAKE_SHARED_LIBRARY_${lang}_FLAGS> <LANGUAGE_COMPILE_FLAGS> <LINK_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS> -o <TARGET> ${CMAKE_GNULD_IMAGE_VERSION} -Xlinker /implib:<TARGET_IMPLIB> -Xlinker /pdb:<TARGET_PDB> -Xlinker /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR> <OBJECTS> <LINK_LIBRARIES>")
   set(CMAKE_${lang}_CREATE_SHARED_MODULE ${CMAKE_${lang}_CREATE_SHARED_LIBRARY})
   set(CMAKE_${lang}_LINK_EXECUTABLE
-    "<CMAKE_${lang}_COMPILER> -nostartfiles -nostdlib <FLAGS> <CMAKE_${lang}_LINK_FLAGS> <LINK_FLAGS> <OBJECTS>  -o <TARGET> -Xlinker /implib:<TARGET_IMPLIB> -Xlinker /pdb:<TARGET_PDB> -Xlinker /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR> ${CMAKE_GNULD_IMAGE_VERSION} <LINK_LIBRARIES>")
+    "<CMAKE_${lang}_COMPILER> -fuse-ld=lld-link -nostartfiles -nostdlib <FLAGS> <CMAKE_${lang}_LINK_FLAGS> <LINK_FLAGS> <OBJECTS>  -o <TARGET> -Xlinker /implib:<TARGET_IMPLIB> -Xlinker /pdb:<TARGET_PDB> -Xlinker /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR> ${CMAKE_GNULD_IMAGE_VERSION} <LINK_LIBRARIES>")
 
   set(CMAKE_${lang}_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreaded         -Xclang -flto-visibility-public-std -D_MT -Xclang --dependent-lib=libcmt)
   set(CMAKE_${lang}_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreadedDLL      -D_DLL -D_MT -Xclang --dependent-lib=msvcrt)
-- 
cgit v0.12