diff options
| author | Yixun Lan <dlan@gentoo.org> | 2022-08-09 16:45:09 +0800 |
|---|---|---|
| committer | Yixun Lan <dlan@gentoo.org> | 2022-08-11 21:14:14 +0800 |
| commit | ac3213e683e4c62c50dc02fef3b168d883245094 (patch) | |
| tree | cff2dbe4f1f75fa238c7d3dfaeb555b2ed88c031 /cmake | |
| parent | 61f7ea86a6e559209135995530a4b105eeed744b (diff) | |
[cmake] link atomic library for certain CPU architectures
For those CPU architectures:
RISC-V lack 8-bit and 16-bit atomic instructions, and
ARM/MIPS/PPC lack 64-bit atomic instruction.
GCC is supposed to convert these atomics via masking and shifting
like LLVM, which means anything that wants to use these instructions
needs the link option -latomic.
In this patch, we will try to detect if 8-bit, 64-bit atomic instructions exist,
otherwise the atomic library will append to the DEPLIBS list.
Original issue:
* https://gitlab.kitware.com/cmake/cmake/-/issues/23021#note_1098733
For reference:
* https://gcc.gnu.org/wiki/Atomic/GCCMM
riscv64 specific:
* https://lists.debian.org/debian-riscv/2022/01/msg00009.html
Signed-off-by: Yixun Lan <dlan@gentoo.org>
Diffstat (limited to 'cmake')
| -rw-r--r-- | cmake/modules/FindAtomic.cmake | 56 | ||||
| -rw-r--r-- | cmake/scripts/linux/ArchSetup.cmake | 3 |
2 files changed, 59 insertions, 0 deletions
diff --git a/cmake/modules/FindAtomic.cmake b/cmake/modules/FindAtomic.cmake new file mode 100644 index 0000000000..8ea3c815d7 --- /dev/null +++ b/cmake/modules/FindAtomic.cmake @@ -0,0 +1,56 @@ +#.rst: +# FindAtomic +# ----- +# Finds the ATOMIC library +# +# This will define the following variables:: +# +# ATOMIC_FOUND - system has ATOMIC +# ATOMIC_LIBRARIES - the ATOMIC libraries +# +# and the following imported targets:: +# +# ATOMIC::ATOMIC - The ATOMIC library + + +include(CheckCXXSourceCompiles) + +set(atomic_code + " + #include <atomic> + #include <cstdint> + std::atomic<uint8_t> n8 (0); // riscv64 + std::atomic<uint64_t> n64 (0); // armel, mipsel, powerpc + int main() { + ++n8; + ++n64; + return 0; + }") + +check_cxx_source_compiles("${atomic_code}" ATOMIC_LOCK_FREE_INSTRUCTIONS) + +if(ATOMIC_LOCK_FREE_INSTRUCTIONS) + set(ATOMIC_FOUND TRUE) + set(ATOMIC_LIBRARIES) +else() + set(CMAKE_REQUIRED_LIBRARIES "-latomic") + check_cxx_source_compiles("${atomic_code}" ATOMIC_IN_LIBRARY) + set(CMAKE_REQUIRED_LIBRARIES) + if(ATOMIC_IN_LIBRARY) + set(ATOMIC_LIBRARY atomic) + include(FindPackageHandleStandardArgs) + find_package_handle_standard_args(Atomic DEFAULT_MSG ATOMIC_LIBRARY) + set(ATOMIC_LIBRARIES ${ATOMIC_LIBRARY}) + if(NOT TARGET ATOMIC::ATOMIC) + add_library(ATOMIC::ATOMIC UNKNOWN IMPORTED) + set_target_properties(ATOMIC::ATOMIC PROPERTIES + IMPORTED_LOCATION "${ATOMIC_LIBRARY}") + endif() + unset(ATOMIC_LIBRARY) + else() + if(Atomic_FIND_REQUIRED) + message(FATAL_ERROR "Neither lock free instructions nor -latomic found.") + endif() + endif() +endif() +unset(atomic_code) diff --git a/cmake/scripts/linux/ArchSetup.cmake b/cmake/scripts/linux/ArchSetup.cmake index 35ab1402f5..848723af1f 100644 --- a/cmake/scripts/linux/ArchSetup.cmake +++ b/cmake/scripts/linux/ArchSetup.cmake @@ -199,3 +199,6 @@ if(NOT USE_INTERNAL_LIBS) set(USE_INTERNAL_LIBS OFF) endif() endif() + +# Atomic library +list(APPEND PLATFORM_REQUIRED_DEPS Atomic) |