From 2f6d2e5795382f0d6e22f5aea52e8104110d24ad Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Sun, 19 Jul 2020 16:29:15 +0200 Subject: [PATCH] cmake/compilerFlags.cmake: properly detect availability of flags Instead of relying on fragile and complex logic to decide if a compiler flag is available or not, use the check_c_compiler_flag() macro provided by the CMake standard library. This for example avoids using -fcf-protection on architectures that don't support this option. [Upstream: https://github.com/Exiv2/exiv2/pull/1252. The submitted patch is slightly different than this one, due to other changes between 0.27.3 and master.] Signed-off-by: Thomas Petazzoni --- cmake/compilerFlags.cmake | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/cmake/compilerFlags.cmake b/cmake/compilerFlags.cmake index 0418aa61..be430977 100644 --- a/cmake/compilerFlags.cmake +++ b/cmake/compilerFlags.cmake @@ -1,4 +1,5 @@ # These flags applies to exiv2lib, the applications, and to the xmp code +include(CheckCCompilerFlag) if ( MINGW OR UNIX OR MSYS ) # MINGW, Linux, APPLE, CYGWIN if (${CMAKE_CXX_COMPILER_ID} STREQUAL GNU) @@ -25,13 +26,16 @@ if ( MINGW OR UNIX OR MSYS ) # MINGW, Linux, APPLE, CYGWIN # This fails under Fedora, MinGW GCC 8.3.0 and CYGWIN/MSYS 9.3.0 if (NOT (MINGW OR CMAKE_HOST_SOLARIS OR CYGWIN OR MSYS) ) - if (COMPILER_IS_GCC AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 8.0) - add_compile_options(-fstack-clash-protection -fcf-protection) - endif() - - if( (COMPILER_IS_GCC AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 5.0) # Not in GCC 4.8 - OR (COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 3.7) # Not in Clang 3.4.2 - ) + check_c_compiler_flag(-fstack-clash-protection HAS_FSTACK_CLASH_PROTECTION) + check_c_compiler_flag(-fcf-protection HAS_FCF_PROTECTION) + check_c_compiler_flag(-fstack-protector-strong HAS_FSTACK_PROTECTOR_STRONG) + if(HAS_FSTACK_CLASH_PROTECTION) + add_compile_options(-fstack-clash-protection) + endif() + if(GCC_HAS_FCF_PROTECTION) + add_compile_options(-fcf-protection) + endif() + if(GCC_HAS_FSTACK_PROTECTOR_STRONG) add_compile_options(-fstack-protector-strong) endif() endif() --- 2.26.2