Merge topic 'clang-ipo-support'

dca9c33abc Tests: Remove old IPO test
c856d4556b bindexplib: supporting llvm bitcode formats using llvm-nm
079b8e2916 Clang: prefer lld-link over link.exe
6e3655db2c Clang: add LTO support for GNU-command line clang on windows

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !3527

2 files changed, 26 insertions, 3 deletions

diff --git a/Modules/CMakeFindBinUtils.cmake b/Modules/CMakeFindBinUtils.cmake
index 773ee53..01f9dae 100644
--- a/Modules/CMakeFindBinUtils.cmake
+++ b/Modules/CMakeFindBinUtils.cmake
@@ -69,7 +69,12 @@ if(("x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_SIMULATE_ID}" STREQUAL "xMSVC" AND
    OR (CMAKE_GENERATOR MATCHES "Visual Studio"
        AND NOT CMAKE_VS_PLATFORM_NAME STREQUAL "Tegra-Android"))
 
-  find_program(CMAKE_LINKER NAMES link HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
+  if("x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_ID}" STREQUAL "xClang")
+    find_program(CMAKE_NM NAMES ${_CMAKE_TOOLCHAIN_PREFIX}nm llvm-nm HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
+    set(_CMAKE_ADDITIONAL_LINKER_NAMES "lld-link")
+  endif()
+
+  find_program(CMAKE_LINKER NAMES ${_CMAKE_ADDITIONAL_LINKER_NAMES} link HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
   find_program(CMAKE_MT     NAMES mt   HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
 
   list(APPEND _CMAKE_TOOL_VARS LINKER MT)
@@ -115,6 +120,17 @@ else()
 
   list(APPEND _CMAKE_TOOL_VARS AR RANLIB STRIP LINKER NM OBJDUMP OBJCOPY READELF DLLTOOL ADDR2LINE)
 
+
+  unset(_CMAKE_ADDITIONAL_AR_NAMES)
+  unset(_CMAKE_ADDITIONAL_RANLIB_NAMES)
+  unset(_CMAKE_ADDITIONAL_STRIP_NAMES)
+  unset(_CMAKE_ADDITIONAL_LINKER_NAMES)
+  unset(_CMAKE_ADDITIONAL_NM_NAMES)
+  unset(_CMAKE_ADDITIONAL_OBJDUMP_NAMES)
+  unset(_CMAKE_ADDITIONAL_OBJCOPY_NAMES)
+  unset(_CMAKE_ADDITIONAL_READELF_NAMES)
+  unset(_CMAKE_ADDITIONAL_DLLTOOL_NAMES)
+  unset(_CMAKE_ADDITIONAL_ADDR2LINE_NAMES)
 endif()
 
 if(CMAKE_PLATFORM_HAS_INSTALLNAME)
diff --git a/Modules/Platform/Windows-Clang.cmake b/Modules/Platform/Windows-Clang.cmake
index 220649c..84b3a9b 100644
--- a/Modules/Platform/Windows-Clang.cmake
+++ b/Modules/Platform/Windows-Clang.cmake
@@ -47,15 +47,22 @@ 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)