From f6dda7cb44c6ee37108f8bb87e606f05563675fe Mon Sep 17 00:00:00 2001
From: Petr Hosek <phosek@chromium.org>
Date: Tue, 22 May 2018 01:01:56 +0000
Subject: [PATCH] [CMake] Use a different source depending on C++ support

When using system C++ library, assume we have a working C++ compiler and
try to compile a complete C++ program. When using in tree C++ library,
only check the C compiler since the C++ library likely won't have been
built yet at time of running the check.

Differential Revision: https://reviews.llvm.org/D47169

llvm-svn: 332924
---
 compiler-rt/cmake/Modules/CompilerRTUtils.cmake | 17 ++++++++++++++++-
 compiler-rt/cmake/config-ix.cmake               |  7 -------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
index f567202faa61..506c06b60845 100644
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -125,6 +125,19 @@ endfunction()
 #   2) simple file can be successfully built.
 # If successful, saves target flags for this architecture.
 macro(test_target_arch arch def)
+  string(RANDOM TARGET_${arch}_NAME)
+  set(TARGET_${arch}_NAME "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/cmTC_${TARGET_${arch}_NAME}.dir")
+  file(MAKE_DIRECTORY ${TARGET_${arch}_NAME})
+  if(SANITIZER_CXX_ABI_INTREE)
+    # We're using in tree C++ ABI, only test the C compiler for now.
+    set(TARGET_${arch}_FILENAME "${TARGET_${arch}_NAME}/CheckTarget.c")
+    file(WRITE "${TARGET_${arch}_FILENAME}" "#include <stdlib.h>\nint main() { void *p = malloc(1); return 0; }\n")
+  else()
+    # We're using the system C++ ABI, test that we can build C++ programs.
+    set(TARGET_${arch}_FILENAME "${TARGET_${arch}_NAME}/CheckTarget.cpp")
+    file(WRITE "${TARGET_${arch}_FILENAME}" "#include <new>\nint main() { int *p = new int; return 0; }\n")
+  endif()
+
   set(TARGET_${arch}_CFLAGS ${ARGN})
   set(TARGET_${arch}_LINK_FLAGS ${ARGN})
   set(argstring "")
@@ -144,7 +157,7 @@ macro(test_target_arch arch def)
       endif()
       set(SAVED_CMAKE_EXE_LINKER_FLAGS ${CMAKE_EXE_LINKER_FLAGS})
       set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${argstring}")
-      try_compile(CAN_TARGET_${arch} ${CMAKE_BINARY_DIR} ${SIMPLE_SOURCE}
+      try_compile(CAN_TARGET_${arch} ${CMAKE_BINARY_DIR} ${TARGET_${arch}_FILENAME}
                   COMPILE_DEFINITIONS "${TARGET_${arch}_CFLAGS} ${FLAG_NO_EXCEPTIONS}"
                   OUTPUT_VARIABLE TARGET_${arch}_OUTPUT)
       set(CMAKE_EXE_LINKER_FLAGS ${SAVED_CMAKE_EXE_LINKER_FLAGS})
@@ -157,6 +170,8 @@ macro(test_target_arch arch def)
     # Bail out if we cannot target the architecture we plan to test.
     message(FATAL_ERROR "Cannot compile for ${arch}:\n${TARGET_${arch}_OUTPUT}")
   endif()
+
+  file(REMOVE_RECURSE ${TARGET_${arch}_NAME})
 endmacro()
 
 macro(detect_target_arch)
diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index ee387dc2267a..8271a9686995 100644
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -121,13 +121,6 @@ endif()
 # List of all architectures we can target.
 set(COMPILER_RT_SUPPORTED_ARCH)
 
-# Try to compile a very simple source file to ensure we can target the given
-# platform. We use the results of these tests to build only the various target
-# runtime libraries supported by our current compilers cross-compiling
-# abilities.
-set(SIMPLE_SOURCE ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/simple.cc)
-file(WRITE ${SIMPLE_SOURCE} "#include <stdlib.h>\n#include <stdio.h>\nint main() { printf(\"hello, world\"); }\n")
-
 # Detect whether the current target platform is 32-bit or 64-bit, and setup
 # the correct commandline flags needed to attempt to target 32-bit and 64-bit.
 if (NOT CMAKE_SIZEOF_VOID_P EQUAL 4 AND