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Differential D71135

[cxx][cxxabi] Don't link libpthread and libdl on Fuchsia
ClosedPublic

Authored by phosek on Dec 6 2019, 11:13 AM.

Details

Reviewers
leonardchan
mclow.lists
Commits
rG1aa170238192: [libcxx{,abi}] Don't link libpthread and libdl on Fuchsia
Summary

These are a part of the libc and embeding these as dependent libraries
causes link time error.

Diff Detail

Event Timeline

phosek created this revision.Dec 6 2019, 11:13 AM
Herald added a project: Restricted Project. · View Herald TranscriptDec 6 2019, 11:13 AM
Herald added subscribers: libcxx-commits, jfb, christof, mgorny. · View Herald Transcript
leonardchan accepted this revision.Dec 6 2019, 11:14 AM
This revision is now accepted and ready to land.Dec 6 2019, 11:14 AM
Herald added a reviewer: mclow.lists. · View Herald TranscriptDec 6 2019, 11:14 AM
Closed by commit rG1aa170238192: [libcxx{,abi}] Don't link libpthread and libdl on Fuchsia (authored by phosek). · Explain WhyDec 6 2019, 11:18 AM
This revision was automatically updated to reflect the committed changes.
mgorny added a comment.Dec 6 2019, 11:25 AM

If it causes link-time error, why CMake checks don't catch that?

phosek mentioned this in D71641: [unwind] Don't link libpthread and libdl on Fuchsia.Dec 17 2019, 5:19 PM
phosek added a comment.Dec 17 2019, 5:22 PM
In D71135#1773192, @mgorny wrote:

If it causes link-time error, why CMake checks don't catch that?

Because CMake never tries to use the just built libc++.a or libc++abi.a and link a binary against it which is where this issue manifests.

phosek mentioned this in rG547659ae56f5: [unwind] Don't link libpthread and libdl on Fuchsia.Dec 17 2019, 5:29 PM

Revision Contents

PathSize
libcxx/
cmake/
5 lines
libcxxabi/
cmake/
18 lines

Diff 232615

libcxx/cmake/config-ix.cmake

Show First 20 Lines • Show All 83 Lines • ▼ Show 20 Linesif(WIN32 AND NOT MINGW)
set(LIBCXX_HAS_M_LIB NO) set(LIBCXX_HAS_M_LIB NO)
set(LIBCXX_HAS_RT_LIB NO) set(LIBCXX_HAS_RT_LIB NO)
set(LIBCXX_HAS_SYSTEM_LIB NO) set(LIBCXX_HAS_SYSTEM_LIB NO)
elseif(APPLE) elseif(APPLE)
check_library_exists(System write "" LIBCXX_HAS_SYSTEM_LIB) check_library_exists(System write "" LIBCXX_HAS_SYSTEM_LIB)
set(LIBCXX_HAS_PTHREAD_LIB NO) set(LIBCXX_HAS_PTHREAD_LIB NO)
set(LIBCXX_HAS_M_LIB NO) set(LIBCXX_HAS_M_LIB NO)
set(LIBCXX_HAS_RT_LIB NO) set(LIBCXX_HAS_RT_LIB NO)
elseif(FUCHSIA)
set(LIBCXX_HAS_M_LIB NO)
set(LIBCXX_HAS_PTHREAD_LIB NO)
set(LIBCXX_HAS_RT_LIB NO)
set(LIBCXX_HAS_SYSTEM_LIB NO)
else() else()
check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB) check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)
check_library_exists(m ccos "" LIBCXX_HAS_M_LIB) check_library_exists(m ccos "" LIBCXX_HAS_M_LIB)
check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB) check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB)
set(LIBCXX_HAS_SYSTEM_LIB NO) set(LIBCXX_HAS_SYSTEM_LIB NO)
endif() endif()

libcxxabi/cmake/config-ix.cmake

Show First 20 Lines • Show All 65 Lines • ▼ Show 20 Lines
" LIBCXXABI_HAS_COMMENT_LIB_PRAGMA) " LIBCXXABI_HAS_COMMENT_LIB_PRAGMA)
cmake_pop_check_state() cmake_pop_check_state()
endif() endif()
# Check compiler flags # Check compiler flags
check_cxx_compiler_flag(-nostdinc++ LIBCXXABI_HAS_NOSTDINCXX_FLAG) check_cxx_compiler_flag(-nostdinc++ LIBCXXABI_HAS_NOSTDINCXX_FLAG)
# Check libraries # Check libraries
if(FUCHSIA)
set(LIBCXXABI_HAS_DL_LIB NO)
set(LIBCXXABI_HAS_PTHREAD_LIB NO)
check_library_exists(c __cxa_thread_atexit_impl ""
LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL)
set(LIBCXXABI_HAS_SYSTEM_LIB NO)
else()
check_library_exists(dl dladdr "" LIBCXXABI_HAS_DL_LIB) check_library_exists(dl dladdr "" LIBCXXABI_HAS_DL_LIB)
check_library_exists(pthread pthread_once "" LIBCXXABI_HAS_PTHREAD_LIB) check_library_exists(pthread pthread_once "" LIBCXXABI_HAS_PTHREAD_LIB)
check_library_exists(c __cxa_thread_atexit_impl "" check_library_exists(c __cxa_thread_atexit_impl ""
LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL) LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL)
check_library_exists(System write "" LIBCXXABI_HAS_SYSTEM_LIB) check_library_exists(System write "" LIBCXXABI_HAS_SYSTEM_LIB)
endif()