[Support] Make building with snmalloc work

[hans]

Summary

Please take a look. See https://reviews.llvm.org/D71786#2265789 for details.

[efriedma]

You can't blindly specify "-mcx16" without checking the target.

[aganea]

Please take a look. See https://reviews.llvm.org/D71786#2265789 for details.

Tested, works for me, thanks!

llvm/lib/Support/CMakeLists.txt

256

In D87471#2266274, @efriedma wrote:

You can't blindly specify "-mcx16" without checking the target.

LLVM_INTEGRATED_CRT_ALLOC is already Windows-only, even though Unix could work too (at least all three allocators support Unix). What about if (${CMAKE_SYSTEM_PROCESSOR} MATCHES "x86_64" (which also accounts for ARM Windows)

[efriedma]

llvm/lib/Support/CMakeLists.txt

256

Sure.

[hans]

Added target condition.

Please take another look.

[aganea]

LGTM.

llvm/lib/Support/CMakeLists.txt

if(LLVM_INTEGRATED_CRT_ALLOC)
   if(NOT EXISTS "${LLVM_INTEGRATED_CRT_ALLOC}")
     message(FATAL_ERROR "Cannot find the path to `git clone` for the CRT allocator! (${LLVM_INTEGRATED_CRT_ALLOC}). Currently, rpmalloc, snmalloc and mimalloc are supported.")
   endif()
 
   if(LLVM_INTEGRATED_CRT_ALLOC MATCHES "rpmalloc$")
     add_definitions(-DENABLE_OVERRIDE -DENABLE_PRELOAD)
     set(ALLOCATOR_FILES "${LLVM_INTEGRATED_CRT_ALLOC}/rpmalloc/rpmalloc.c")
   elseif(LLVM_INTEGRATED_CRT_ALLOC MATCHES "snmalloc$")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /std:c++17" PARENT_SCOPE)
     set(ALLOCATOR_FILES "${LLVM_INTEGRATED_CRT_ALLOC}/src/override/malloc.cc" "${LLVM_INTEGRATED_CRT_ALLOC}/src/override/new.cc")
     set(system_libs ${system_libs} "mincore.lib" "-INCLUDE:malloc")
   elseif(LLVM_INTEGRATED_CRT_ALLOC MATCHES "mimalloc$")
     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")

 
 if(LLVM_ENABLE_TERMINFO)
   get_library_name(${TERMINFO_LIB} terminfo_library)
   set(llvm_system_libs ${llvm_system_libs} "${terminfo_library}")
 endif()
 
 set_property(TARGET LLVMSupport PROPERTY LLVM_SYSTEM_LIBS "${llvm_system_libs}")
 
+
+if(LLVM_INTEGRATED_CRT_ALLOC)
+  if(LLVM_INTEGRATED_CRT_ALLOC MATCHES "snmalloc$")
+    set_property(TARGET LLVMSupport PROPERTY CXX_STANDARD 17)
+    add_definitions(-D_SILENCE_CXX17_ITERATOR_BASE_CLASS_DEPRECATION_WARNING)
+    if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" AND
+        "${CMAKE_SYSTEM_PROCESSOR}" MATCHES "x86_64")
+      set_property(TARGET LLVMSupport PROPERTY COMPILE_FLAGS "-mcx16")
+    endif()
+  endif()
+endif()
+
 if(LLVM_WITH_Z3)
   target_include_directories(LLVMSupport SYSTEM
     PRIVATE
     ${Z3_INCLUDE_DIR}
     )
 endif()