[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
This commit is contained in:
Petr Hosek 2017-04-07 20:10:29 +00:00
parent c9bc745518
commit 3dc83e5e31
1 changed files with 23 additions and 2 deletions

View File

@ -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)