diff options
| author | Daniel Bertalan <dani@danielbertalan.dev> | 2021-11-08 19:06:02 +0100 |
|---|---|---|
| committer | Linus Groh <mail@linusgroh.de> | 2021-11-13 11:15:33 +0000 |
| commit | fe1726521a6928416c001e296a7b2c510ded8570 (patch) | |
| tree | fea761fdd432df031665576c78f3d418134b63e2 /Meta/CMake | |
| parent | 62169fda03666bff7ce041e4e715a7455d997136 (diff) | |
| download | serenity-fe1726521a6928416c001e296a7b2c510ded8570.zip | |
Meta: Resolve cyclic dependency between LibPthread and libc++
libc++ uses a Pthread condition variable in one of its initialization
functions. This means that Pthread forwarding has to be set up in LibC
before libc++ can be initialized. Also, because LibPthread is written in
C++, (at least some) parts of the C++ standard library have to be linked
against it.
This is a circular dependency, which means that the order in which these
two libraries' initialization functions are called is undefined. In some
cases, libc++ will come first, which will then trigger an assert due to
the missing Pthread forwarding.
This issue isn't necessarily unique to LibPthread, as all libraries that
libc++ depends on exhibit the same circular dependency issue.
The reason why this issue didn't affect the GNU toolchain is that
libstdc++ is always linked statically. If we were to change that, I
believe that we would run into the same issue.
Diffstat (limited to 'Meta/CMake')
| -rw-r--r-- | Meta/CMake/utils.cmake | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/Meta/CMake/utils.cmake b/Meta/CMake/utils.cmake index 5670f18bc3..e139d69d14 100644 --- a/Meta/CMake/utils.cmake +++ b/Meta/CMake/utils.cmake @@ -47,8 +47,15 @@ function(serenity_libc target_name fs_name) add_library(${target_name} SHARED ${SOURCES}) install(TARGETS ${target_name} DESTINATION usr/lib) set_target_properties(${target_name} PROPERTIES OUTPUT_NAME ${fs_name}) - if (CMAKE_CXX_COMPILER_ID MATCHES "Clang$") + # Avoid creating a dependency cycle between system libraries and the C++ standard library. This is necessary + # to ensure that initialization functions will be called in the right order (libc++ must come after LibPthread). + if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU") + target_link_options(${target_name} PRIVATE -static-libstdc++) + elseif (CMAKE_CXX_COMPILER_ID MATCHES "Clang$") target_link_libraries(${target_name} clang_rt.builtins) + # FIXME: Implement -static-libstdc++ in the next toolchain update. + target_link_options(${target_name} PRIVATE -nostdlib++ -Wl,-Bstatic -lc++ -Wl,-Bdynamic) + target_link_options(${target_name} PRIVATE -Wl,--no-dependent-libraries) endif() target_link_directories(LibC PUBLIC ${CMAKE_CURRENT_BINARY_DIR}) serenity_generated_sources(${target_name}) |