From 3dc83e5e31e2ef9c2a9ddfd04a1c648d523007ea Mon Sep 17 00:00:00 2001 From: Petr Hosek Date: Fri, 7 Apr 2017 20:10:29 +0000 Subject: [CMake][libunwind] Use -nodefaultlibs for CMake checks Since libunwind is built with -nodefaultlibs, we should be using this option even for CMake checks to avoid any inconsistency and also to avoid dependency on a working C++ standard library just for the setting up the build itself. The implementation is largely similar to the one used by libc++. Differential Revision: https://reviews.llvm.org/D31640 llvm-svn: 299796 --- libunwind/cmake/config-ix.cmake | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) (limited to 'libunwind') diff --git a/libunwind/cmake/config-ix.cmake b/libunwind/cmake/config-ix.cmake index 0b0bb5c..be12ed5 100644 --- a/libunwind/cmake/config-ix.cmake +++ b/libunwind/cmake/config-ix.cmake @@ -3,13 +3,35 @@ include(CheckCCompilerFlag) include(CheckCXXCompilerFlag) include(CheckLibraryExists) +check_library_exists(c fopen "" LIBUNWIND_HAS_C_LIB) + +# libunwind is built with -nodefaultlibs, so we want all our checks to also +# use this option, otherwise we may end up with an inconsistency between +# the flags we think we require during configuration (if the checks are +# performed without -nodefaultlibs) and the flags that are actually +# required during compilation (which has the -nodefaultlibs). libc is +# required for the link to go through. We remove sanitizers from the +# configuration checks to avoid spurious link errors. +check_c_compiler_flag(-nodefaultlibs LIBUNWIND_HAS_NODEFAULTLIBS_FLAG) +if (LIBUNWIND_HAS_NODEFAULTLIBS_FLAG) + set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs") + if (LIBUNWIND_HAS_C_LIB) + list(APPEND CMAKE_REQUIRED_LIBRARIES c) + endif () + if (CMAKE_C_FLAGS MATCHES -fsanitize OR CMAKE_CXX_FLAGS MATCHES -fsanitize) + set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fno-sanitize=all") + endif () + if (CMAKE_C_FLAGS MATCHES -fsanitize-coverage OR CMAKE_CXX_FLAGS MATCHES -fsanitize-coverage) + set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fno-sanitize-coverage=edge,trace-cmp,indirect-calls,8bit-counters") + endif () +endif () + # Check compiler flags check_c_compiler_flag(-funwind-tables LIBUNWIND_HAS_FUNWIND_TABLES) check_cxx_compiler_flag(-fPIC LIBUNWIND_HAS_FPIC_FLAG) check_cxx_compiler_flag(-fno-exceptions LIBUNWIND_HAS_NO_EXCEPTIONS_FLAG) check_cxx_compiler_flag(-fno-rtti LIBUNWIND_HAS_NO_RTTI_FLAG) check_cxx_compiler_flag(-fstrict-aliasing LIBUNWIND_HAS_FSTRICT_ALIASING_FLAG) -check_cxx_compiler_flag(-nodefaultlibs LIBUNWIND_HAS_NODEFAULTLIBS_FLAG) check_cxx_compiler_flag(-nostdinc++ LIBUNWIND_HAS_NOSTDINCXX_FLAG) check_cxx_compiler_flag(-Wall LIBUNWIND_HAS_WALL_FLAG) check_cxx_compiler_flag(-W LIBUNWIND_HAS_W_FLAG) @@ -44,7 +66,6 @@ if(LIBUNWIND_HAS_STD_CXX11) set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11") endif() -check_library_exists(c fopen "" LIBUNWIND_HAS_C_LIB) check_library_exists(dl dladdr "" LIBUNWIND_HAS_DL_LIB) check_library_exists(pthread pthread_once "" LIBUNWIND_HAS_PTHREAD_LIB) -- cgit v1.1