[LLVM][CMake][MSVC] Wrap linker flags for ICX on Windows (#112680)

The Intel C++ Compiler (ICX) passes linker flags through the driver
unlike MSVC and clang-cl, and therefore needs them to be prefixed with
`/Qoption,link` (the equivalent of `-Wl,` for gcc on *nix).

Use `LINKER:` prefix wherever supported by cmake, when that's not
possible fall-back to `${CMAKE_CXX_LINKER_WRAPPER_FLAG}`. CMake replaces
these with `/Qoption,link` for ICX and with the empty string for MSVC
and clang-cl.

For `target_link_libraries` neither `LINKER:` (not supported prior to
CMake 3.32) nor `${CMAKE_CXX_LINKER_WRAPPER_FLAG}` (does not begin with
`-` would be taken as a library name) works, use `-Qoption,link`
directly within a conditional generator expression that we're linking
with ICX.

For MSVC and clang-cl no functional change is intended.

Tested by compiling with ICX and setting
`CMAKE_(EXE|SHARED|STATIC|MODULE)_LINKER_FLAGS_INIT` to
`-Werror=unknown-argument`.

RFC:
https://discourse.llvm.org/t/rfc-cmake-linker-flags-need-wl-equivalent-for-intel-c-icx-on-windows/82446

Author: Maetveis

llvm/cmake/modules/AddLLVM.cmake

@@ -149,20 +149,20 @@ function(add_llvm_symbol_exports target_name export_file)
     set(export_file_linker_flag "${CMAKE_CURRENT_BINARY_DIR}/${native_export_file}")
     if(MSVC)
       # cl.exe or clang-cl, i.e. MSVC style command line interface
-      set(export_file_linker_flag "/DEF:\"${export_file_linker_flag}\"")
+      set(export_file_linker_flag "LINKER:/DEF:${export_file_linker_flag}")
     elseif(CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC")
       # clang in msvc mode, calling a link.exe/lld-link style linker
-      set(export_file_linker_flag "-Wl,/DEF:\"${export_file_linker_flag}\"")
+      set(export_file_linker_flag "-Wl,/DEF:${export_file_linker_flag}")
     elseif(MINGW)
       # ${export_file_linker_flag}, which is the plain file name, works as is
       # when passed to the compiler driver, which then passes it on to the
       # linker as an input file.
-      set(export_file_linker_flag "\"${export_file_linker_flag}\"")
+      set(export_file_linker_flag "${export_file_linker_flag}")
     else()
       message(FATAL_ERROR "Unsupported Windows toolchain")
     endif()
-    set_property(TARGET ${target_name} APPEND_STRING PROPERTY
-                 LINK_FLAGS " ${export_file_linker_flag}")
+    set_property(TARGET ${target_name} APPEND PROPERTY
+                 LINK_OPTIONS "${export_file_linker_flag}")
   endif()
 
   add_custom_target(${target_name}_exports DEPENDS ${native_export_file})

llvm/cmake/modules/HandleLLVMOptions.cmake

@@ -542,7 +542,7 @@ if(MSVC)
   # behavior was changed in CMake 2.8.11 (Issue 12437) to use the MSVC default
   # value (1 MB) which is not enough for us in tasks such as parsing recursive
   # C++ templates in Clang.
-  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
+  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_CXX_LINKER_WRAPPER_FLAG}/STACK:10000000")
 elseif(MINGW OR CYGWIN)
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--stack,16777216")
 

llvm/cmake/platforms/WinMsvc.cmake

@@ -324,6 +324,10 @@ if(case_sensitive_filesystem)
        -libpath:"${msvc_lib_symlinks_dir}")
 endif()
 
+if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.25")
+  list(TRANSFORM LINK_FLAGS PREPEND "${CMAKE_CXX_LINKER_WRAPPER_FLAG}")
+endif()
+
 string(REPLACE ";" " " LINK_FLAGS "${LINK_FLAGS}")
 string(APPEND CMAKE_EXE_LINKER_FLAGS_INIT " ${LINK_FLAGS}")
 string(APPEND CMAKE_MODULE_LINKER_FLAGS_INIT " ${LINK_FLAGS}")

llvm/lib/Support/CMakeLists.txt

@@ -74,14 +74,22 @@ elseif( CMAKE_HOST_UNIX )
   endif()
 endif( WIN32 )
 
+set(WL "")
+if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.25"
+   AND MSVC
+   AND NOT CMAKE_GENERATOR MATCHES "Visual Studio")
+  #IntelLLVM requires to pass linker flags with a wrapper
+  set(WL "$<$<OR:$<LINK_LANG_AND_ID:C,IntelLLVM>,$<LINK_LANG_AND_ID:CXX,IntelLLVM>,$<LINK_LANG_AND_ID:Fortran,IntelLLVM>>:-Qoption,link,>")
+endif()
+
 # Delay load shell32.dll if possible to speed up process startup.
 set (delayload_flags)
 if (MSVC)
   # When linking with Swift, `swiftc.exe` is used as the linker drive rather
   # than invoking `link.exe` directly.  In such a case, the flags should be
   # marked as `-Xlinker` to pass them directly to the linker.  As a temporary
   # workaround simply elide the delay loading.
-  set (delayload_flags $<$<NOT:$<LINK_LANGUAGE:Swift>>:delayimp -delayload:shell32.dll -delayload:ole32.dll>)
+  set (delayload_flags $<$<NOT:$<LINK_LANGUAGE:Swift>>:delayimp ${WL}-delayload:shell32.dll ${WL}-delayload:ole32.dll>)
 endif()
 
 # Link Z3 if the user wants to build it.
@@ -104,16 +112,16 @@ if(LLVM_INTEGRATED_CRT_ALLOC)
   if((LLVM_INTEGRATED_CRT_ALLOC MATCHES "rpmalloc$") OR LLVM_ENABLE_RPMALLOC)
     add_compile_definitions(ENABLE_OVERRIDE ENABLE_PRELOAD)
     set(ALLOCATOR_FILES "${LLVM_INTEGRATED_CRT_ALLOC}/rpmalloc/rpmalloc.c")
-    set(delayload_flags "${delayload_flags} -INCLUDE:malloc")
+    set(delayload_flags "${delayload_flags} ${WL}-INCLUDE:malloc")
   elseif(LLVM_INTEGRATED_CRT_ALLOC MATCHES "snmalloc$")
     set(ALLOCATOR_FILES "${LLVM_INTEGRATED_CRT_ALLOC}/src/snmalloc/override/new.cc")
-    set(system_libs ${system_libs} "mincore.lib" "-INCLUDE:malloc")
+    set(system_libs ${system_libs} "mincore.lib" "${WL}-INCLUDE:malloc")
   elseif(LLVM_INTEGRATED_CRT_ALLOC MATCHES "mimalloc$")
     set(MIMALLOC_LIB "${LLVM_INTEGRATED_CRT_ALLOC}/out/msvc-x64/Release/mimalloc-static.lib")
     if(NOT EXISTS "${MIMALLOC_LIB}")
 	  message(FATAL_ERROR "Cannot find the mimalloc static library. To build it, first apply the patch from https://github.com/microsoft/mimalloc/issues/268 then build the Release x64 target through ${LLVM_INTEGRATED_CRT_ALLOC}\\ide\\vs2019\\mimalloc.sln")
     endif()
-    set(system_libs ${system_libs} "${MIMALLOC_LIB}" "-INCLUDE:malloc")
+    set(system_libs ${system_libs} "${MIMALLOC_LIB}" "${WL}-INCLUDE:malloc")
   endif()
 endif()
 

llvm/tools/llvm-shlib/CMakeLists.txt

@@ -188,7 +188,7 @@ if(LLVM_BUILD_LLVM_C_DYLIB AND MSVC)
 
   if (LLVM_INTEGRATED_CRT_ALLOC AND MSVC)
     # Make sure we search LLVMSupport first, before the CRT libs
-    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -INCLUDE:malloc")
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${CMAKE_CXX_LINKER_WRAPPER_FLAG}-INCLUDE:malloc")
   endif()
 
 endif()