[compiler-rt] Fix wrong output path of external project target in MSVC.

[sunho]

Summary

Fixes wrong output path of external project target in MSVC. It simplifies the conditional to use ".lib" suffix even if MINGW is not defied. (the not MINGW does not hit when MINGW is NOTFOUND) The behavior before this patch in MSVC was outputting ".a" for static libraries.

[mstorsjo]

compiler-rt/cmake/base-config-ix.cmake

156

This change on its own is probably ok.

llvm/runtimes/CMakeLists.txt

66 ↗

(On Diff #459360)

This change will change how runtime libraries are built for a lot of platforms! You can’t sneak a change like this into a patch that is just labeled to change compiler-rt! Cc @MaskRay @phosek

[MaskRay]

llvm/runtimes/CMakeLists.txt

66 ↗

(On Diff #459360)

https://discourse.llvm.org/t/rfc-time-to-drop-legacy-runtime-paths/64628/18 @daltenty

[sunho]

llvm/runtimes/CMakeLists.txt

66 ↗

(On Diff #459360)

Oh I was not correctly understanding the complexity here. I can drop this change in the mean time -- ORC is totally fine to use the new per-targrt directory even in MSVC.

[phosek]

compiler-rt/cmake/base-config-ix.cmake

156

I'm a bit surprised that this is even needed, according to CMake documentation, this should already be the default: https://cmake.org/cmake/help/v3.14/variable/CMAKE_STATIC_LIBRARY_SUFFIX.html

[sunho]

compiler-rt/cmake/base-config-ix.cmake

156

@phosek We're using clang-cl to build runtimes target by llvm_ExternalProject_Add. Cmake seems to be setting ".a" suffix when using clang to build MSVC target. This part is a workaround introduced by https://reviews.llvm.org/D24046 to fight this issue.

[sunho]

Keep only the part relevant for MSVC.

[sunho]

This is actually not related to the conditionals but related to something in my system or cmake which causes it to set MINGW to true. Abandoning this patch as it is going to break clang-cl building case anyways.

compiler-rt/cmake/Modules/AddCompilerRT.cmake

foreach(libname ${libnames})
     endif()
     if(builtins_${libname})
       target_link_libraries(${libname} PRIVATE ${builtins_${libname}})
     endif()
     if(${type} STREQUAL "SHARED")
       if(COMMAND llvm_setup_rpath)
         llvm_setup_rpath(${libname})
       endif()
-      if(WIN32 AND NOT CYGWIN AND NOT MINGW)
+      if(MSVC)
         set_target_properties(${libname} PROPERTIES IMPORT_PREFIX "")
         set_target_properties(${libname} PROPERTIES IMPORT_SUFFIX ".lib")
       endif()
       if (APPLE AND NOT CMAKE_LINKER MATCHES ".*lld.*")
         # Ad-hoc sign the dylibs when using Xcode versions older than 12.
         # Xcode 12 shipped with ld64-609.
         # FIXME: Remove whole conditional block once everything uses Xcode 12+.
         set(LD_V_OUTPUT)

compiler-rt/cmake/base-config-ix.cmake

if(APPLE)
   option(COMPILER_RT_ENABLE_IOS "Enable building for iOS" On)
   option(COMPILER_RT_ENABLE_WATCHOS "Enable building for watchOS - Experimental" Off)
   option(COMPILER_RT_ENABLE_TVOS "Enable building for tvOS - Experimental" Off)
 
 else()
   option(COMPILER_RT_DEFAULT_TARGET_ONLY "Build builtins only for the default target" Off)
 endif()
 
-if(WIN32 AND NOT MINGW AND NOT CYGWIN)
+if(MSVC)
   set(CMAKE_SHARED_LIBRARY_PREFIX_C "")
   set(CMAKE_SHARED_LIBRARY_PREFIX_CXX "")
   set(CMAKE_STATIC_LIBRARY_PREFIX_C "")
   set(CMAKE_STATIC_LIBRARY_PREFIX_CXX "")
   set(CMAKE_STATIC_LIBRARY_SUFFIX_C ".lib")
   set(CMAKE_STATIC_LIBRARY_SUFFIX_CXX ".lib")
 endif()