From 5d5a7123034361b6cacff96d3ed20d2bb78c33cc Mon Sep 17 00:00:00 2001
From: "William R. Dieter" <william.r.dieter@intel.com>
Date: Fri, 27 May 2022 14:22:01 -0700
Subject: IntelLLVM: Pass linker flags to the compiler when used as linker

When linking an executable, DLL, or static library, the compiler sometimes
needs to see the linking options.  Typically `<FLAGS>` is not passed
for linking, because some of the options are only used for compilation.
Previously, `<LINK_FLAGS>` was passed after the `/link` flag because
the compiler did not understand some of the linking options.

This change wraps the initial linker options borrowed from Windows-MSVC
individually, so that they are passed directly to the linker.

This change is helpful both for interprocedural optimization, which needs
to pass `-Qipo` to the compiler at link time, and for SYCL which needs
to pass `-fsycl` and possibly other options to the compiler at link time.

Signed-off-by: William R. Dieter <william.r.dieter@intel.com>
---
 Modules/Platform/Windows-IntelLLVM.cmake | 51 +++++++++++++++++++++++++++-----
 1 file changed, 43 insertions(+), 8 deletions(-)

diff --git a/Modules/Platform/Windows-IntelLLVM.cmake b/Modules/Platform/Windows-IntelLLVM.cmake
index f24dcdb..43f5874 100644
--- a/Modules/Platform/Windows-IntelLLVM.cmake
+++ b/Modules/Platform/Windows-IntelLLVM.cmake
@@ -3,26 +3,61 @@
 
 
 # This module is shared by multiple languages; use include blocker.
-if(__WINDOWS_INTEL)
+if(__WINDOWS_INTEL_LLVM)
   return()
 endif()
-set(__WINDOWS_INTEL 1)
+set(__WINDOWS_INTEL_LLVM 1)
 
+# Platform/Windows-MSVC adds some linking options icx/ifx do not understand,
+# but that need to be passed to the linker.  Wrap all the linking options from
+# Platform/Windows-MSVC so that the compiler will hand them off to the linker
+# without interpreting them.
+
+# Save original CMAKE_${t}_LINKER_FLAGS_INIT
+foreach(t EXE SHARED MODULE STATIC)
+  set(_saved_cmake_${t}_linker_flags_init ${CMAKE_${t}_LINKER_FLAGS_INIT})
+  set(CMAKE_${t}_LINKER_FLAGS_INIT "")
+endforeach()
 include(Platform/Windows-MSVC)
+# Wrap linker flags from Windows-MSVC
+set(_IntelLLVM_LINKER_WRAPPER_FLAG "/Qoption,link,")
+set(_IntelLLVM_LINKER_WRAPPER_FLAG_SEP ",")
+foreach(t EXE SHARED MODULE STATIC)
+  set(_wrapped_linker_flags "")
+  foreach(flag ${CMAKE_${t}_LINKER_FLAGS_INIT})
+    string(STRIP ${flag} flag)
+    list(APPEND _wrapped_linker_flags "${_IntelLLVM_LINKER_WRAPPER_FLAG}${flag}")
+  endforeach()
+  set(CMAKE_${t}_LINKER_FLAGS_INIT "")
+  list(APPEND CMAKE_${t}_LINKER_FLAGS_INIT
+    ${_saved_cmake_${t}_linker_flags_init} ${_wrapped_linker_flags})
+endforeach()
+
 macro(__windows_compiler_intel lang)
   __windows_compiler_msvc(${lang})
 
-  # For DPCPP other offload cases, some link flags need to go to the compiler
-  # driver and others need to go to the linker.  Pass the compiler linking flags
-  # in CMAKE_${lang}_LINK_FLAGS and linker flags in LINK_FLAGS
+  set(CMAKE_${lang}_LINKER_WRAPPER_FLAG "${_IntelLLVM_LINKER_WRAPPER_FLAG}")
+  set(CMAKE_${lang}_LINKER_WRAPPER_FLAG_SEP "${_IntelLLVM_LINKER_WRAPPER_FLAG_SEP}")
+  set(CMAKE_${lang}_CREATE_WIN32_EXE "${CMAKE_${lang}_LINKER_WRAPPER_FLAG}/subsystem:windows")
+  set(CMAKE_${lang}_CREATE_CONSOLE_EXE "${CMAKE_${lang}_LINKER_WRAPPER_FLAG}/subsystem:console")
+  set(CMAKE_LINK_DEF_FILE_FLAG "${CMAKE_${lang}_LINKER_WRAPPER_FLAG}/DEF:")
+  set(CMAKE_LIBRARY_PATH_FLAG "${CMAKE_${lang}_LINKER_WRAPPER_FLAG}/LIBPATH:")
+
+  # Features for LINK_LIBRARY generator expression
+  if(MSVC_VERSION GREATER "1900")
+    ## WHOLE_ARCHIVE: Force loading all members of an archive
+    set(CMAKE_LINK_LIBRARY_USING_WHOLE_ARCHIVE "LINKER:/WHOLEARCHIVE:<LIBRARY>")
+    set(CMAKE_LINK_LIBRARY_USING_WHOLE_ARCHIVE_SUPPORTED TRUE)
+  endif()
+
   set(CMAKE_${lang}_LINK_EXECUTABLE
-    "${_CMAKE_VS_LINK_EXE}<CMAKE_${lang}_COMPILER> ${CMAKE_CL_NOLOGO} <CMAKE_${lang}_LINK_FLAGS> <OBJECTS> ${CMAKE_START_TEMP_FILE} /link /out:<TARGET> /implib:<TARGET_IMPLIB> /pdb:<TARGET_PDB> /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR>${_PLATFORM_LINK_FLAGS} <LINK_FLAGS> <LINK_LIBRARIES>${CMAKE_END_TEMP_FILE}")
+    "${_CMAKE_VS_LINK_EXE}<CMAKE_${lang}_COMPILER> ${CMAKE_CL_NOLOGO} <CMAKE_${lang}_LINK_FLAGS> <OBJECTS> ${CMAKE_START_TEMP_FILE} <LINK_FLAGS> <LINK_LIBRARIES> /link /out:<TARGET> /implib:<TARGET_IMPLIB> /pdb:<TARGET_PDB> /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR>${_PLATFORM_LINK_FLAGS} ${CMAKE_END_TEMP_FILE}")
   set(CMAKE_${lang}_CREATE_SHARED_LIBRARY
-    "${_CMAKE_VS_LINK_DLL}<CMAKE_${lang}_COMPILER> ${CMAKE_CL_NOLOGO} <CMAKE_${lang}_LINK_FLAGS> <OBJECTS> ${CMAKE_START_TEMP_FILE} -LD -link /out:<TARGET> /implib:<TARGET_IMPLIB> /pdb:<TARGET_PDB> /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR>${_PLATFORM_LINK_FLAGS} <LINK_FLAGS> <LINK_LIBRARIES> ${CMAKE_END_TEMP_FILE}")
+    "${_CMAKE_VS_LINK_DLL}<CMAKE_${lang}_COMPILER> ${CMAKE_CL_NOLOGO} <CMAKE_${lang}_LINK_FLAGS> <OBJECTS> ${CMAKE_START_TEMP_FILE} -LD <LINK_FLAGS> <LINK_LIBRARIES> -link /out:<TARGET> /implib:<TARGET_IMPLIB> /pdb:<TARGET_PDB> /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR>${_PLATFORM_LINK_FLAGS} ${CMAKE_END_TEMP_FILE}")
   if (NOT "${lang}" STREQUAL "Fortran" OR CMAKE_${lang}_COMPILER_VERSION VERSION_GREATER_EQUAL 2022.1)
     # The Fortran driver does not support -fuse-ld=llvm-lib before compiler version 2022.1
     set(CMAKE_${lang}_CREATE_STATIC_LIBRARY
-      "<CMAKE_${lang}_COMPILER> ${CMAKE_CL_NOLOGO} <CMAKE_${lang}_LINK_FLAGS> <OBJECTS> ${CMAKE_START_TEMP_FILE} -fuse-ld=llvm-lib -o <TARGET> -link <LINK_FLAGS> <LINK_LIBRARIES> ${CMAKE_END_TEMP_FILE}")
+      "<CMAKE_${lang}_COMPILER> ${CMAKE_CL_NOLOGO} <CMAKE_${lang}_LINK_FLAGS> <OBJECTS> ${CMAKE_START_TEMP_FILE} -fuse-ld=llvm-lib -o <TARGET> <LINK_FLAGS> <LINK_LIBRARIES> ${CMAKE_END_TEMP_FILE}")
   endif()
 
   set(CMAKE_DEPFILE_FLAGS_${lang} "-QMD -QMT <DEP_TARGET> -QMF <DEP_FILE>")
-- 
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