[compiler-rt] r298413 - [compiler-rt] respect CMAKE_EXE_LINKER_FLAGS in compiler and library tests

[Bob Haarman via llvm-commits]

Author: inglorion
Date: Tue Mar 21 13:25:35 2017
New Revision: 298413

URL: http://llvm.org/viewvc/llvm-project?rev=298413&view=rev
Log:
[compiler-rt] respect CMAKE_EXE_LINKER_FLAGS in compiler and library tests

Summary: check_cxx_compiler_flag and check_library_exists could fail because they ignored CMAKE_EXE_LINKER_FLAGS and therefore would always fail to produce executables. Cmake policy CMP0056 fixes this, but was explicitly set to OLD in our CMakeLists because it caused problems with test_target_arch. This change sets the policy to NEW to fix the problem with the compiler and library tests, and temporarily clears CMAKE_EXE_LINKER_FLAGS inside test_target_arch to emulate the old behavior there. This allows, for example, LTO builds that require lld to succeed.

Reviewers: davidxl, beanz

Reviewed By: beanz

Subscribers: fjricci, dberris, mgorny, mehdi_amini, tejohnson, rnk, llvm-commits

Differential Revision: https://reviews.llvm.org/D31098

Modified:
    compiler-rt/trunk/CMakeLists.txt
    compiler-rt/trunk/cmake/Modules/CompilerRTDarwinUtils.cmake
    compiler-rt/trunk/cmake/Modules/CompilerRTUtils.cmake

Modified: compiler-rt/trunk/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/CMakeLists.txt?rev=298413&r1=298412&r2=298413&view=diff
==============================================================================
--- compiler-rt/trunk/CMakeLists.txt (original)
+++ compiler-rt/trunk/CMakeLists.txt Tue Mar 21 13:25:35 2017
@@ -14,16 +14,6 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURR
 endif()
 
 cmake_minimum_required(VERSION 3.4.3)
-# FIXME:
-# The OLD behavior (pre 3.2) for this policy is to not set the value of the 
-# CMAKE_EXE_LINKER_FLAGS variable in the generated test project. The NEW behavior
-# for this policy is to set the value of the CMAKE_EXE_LINKER_FLAGS variable 
-# in the test project to the same as it is in the calling project. The new 
-# behavior cause the compiler_rt test to fail during try_compile: see
-# projects/compiler-rt/cmake/Modules/CompilerRTUtils.cmake:121 such that
-# CAN_TARGET_${arch} is not set properly. This results in COMPILER_RT_SUPPORTED_ARCH
-# not being updated properly leading to poblems.
-cmake_policy(SET CMP0056 OLD)
 
 # Add path for custom compiler-rt modules.
 list(INSERT CMAKE_MODULE_PATH 0

Modified: compiler-rt/trunk/cmake/Modules/CompilerRTDarwinUtils.cmake
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/cmake/Modules/CompilerRTDarwinUtils.cmake?rev=298413&r1=298412&r2=298413&view=diff
==============================================================================
--- compiler-rt/trunk/cmake/Modules/CompilerRTDarwinUtils.cmake (original)
+++ compiler-rt/trunk/cmake/Modules/CompilerRTDarwinUtils.cmake Tue Mar 21 13:25:35 2017
@@ -85,10 +85,12 @@ function(darwin_test_archs os valid_arch
     if(TEST_COMPILE_ONLY)
       try_compile_only(CAN_TARGET_${os}_${arch} -v -arch ${arch} ${DARWIN_${os}_CFLAGS})
     else()
+      set(SAVED_CMAKE_EXE_LINKER_FLAGS ${CMAKE_EXE_LINKER_FLAGS})
+      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${arch_linker_flags}")
       try_compile(CAN_TARGET_${os}_${arch} ${CMAKE_BINARY_DIR} ${SIMPLE_C}
                   COMPILE_DEFINITIONS "-v -arch ${arch}" ${DARWIN_${os}_CFLAGS}
-                  CMAKE_FLAGS "-DCMAKE_EXE_LINKER_FLAGS=${arch_linker_flags}"
                   OUTPUT_VARIABLE TEST_OUTPUT)
+      set(CMAKE_EXE_LINKER_FLAGS ${SAVED_CMAKE_EXE_LINKER_FLAGS})
     endif()
     if(${CAN_TARGET_${os}_${arch}})
       list(APPEND working_archs ${arch})

Modified: compiler-rt/trunk/cmake/Modules/CompilerRTUtils.cmake
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/cmake/Modules/CompilerRTUtils.cmake?rev=298413&r1=298412&r2=298413&view=diff
==============================================================================
--- compiler-rt/trunk/cmake/Modules/CompilerRTUtils.cmake (original)
+++ compiler-rt/trunk/cmake/Modules/CompilerRTUtils.cmake Tue Mar 21 13:25:35 2017
@@ -138,15 +138,16 @@ macro(test_target_arch arch def)
     elseif(TEST_COMPILE_ONLY)
       try_compile_only(CAN_TARGET_${arch} ${TARGET_${arch}_CFLAGS})
     else()
-      set(argstring "${CMAKE_EXE_LINKER_FLAGS} ${argstring}")
       set(FLAG_NO_EXCEPTIONS "")
       if(COMPILER_RT_HAS_FNO_EXCEPTIONS_FLAG)
         set(FLAG_NO_EXCEPTIONS " -fno-exceptions ")
       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} ${SIMPLE_SOURCE}
                   COMPILE_DEFINITIONS "${TARGET_${arch}_CFLAGS} ${FLAG_NO_EXCEPTIONS}"
-                  OUTPUT_VARIABLE TARGET_${arch}_OUTPUT
-                  CMAKE_FLAGS "-DCMAKE_EXE_LINKER_FLAGS:STRING=${argstring}")
+                  OUTPUT_VARIABLE TARGET_${arch}_OUTPUT)
+      set(CMAKE_EXE_LINKER_FLAGS ${SAVED_CMAKE_EXE_LINKER_FLAGS})
     endif()
   endif()
   if(${CAN_TARGET_${arch}})