serenity/Meta/CMake/common_compile_options.cmake
Dan Klishch 56b7f9e404 Meta: Globally disable -Wpsabi
This warning is triggered when one accepts or returns vectors from a
function (that is not marked with [[gnu::target(...)]]) which would have
been otherwise passed in register if the current translation unit had
been compiled with more permissive flags wrt instruction selection (i.
e. if one adds -mavx2 to cmdline). This will never be a problem for us
since we (a) never use different instruction selection options across
ABI boundaries; (b) most of the affected functions are actually
TU-local.

Moreover, even if we somehow properly annotated all of the SIMD helpers,
calling them across ABI (or target) boundaries would still be very
dangerous because of inconsistent and bogus handling of
[[gnu::target(...)]] across compilers. See
https://github.com/llvm/llvm-project/issues/64706 and
https://www.reddit.com/r/cpp/comments/17qowl2/comment/k8j2odi .
2024-07-12 18:30:07 -04:00

63 lines
2.7 KiB
CMake

# Flags shared by Lagom (including Ladybird) and Serenity.
set(CMAKE_CXX_STANDARD 23)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
set(CMAKE_COLOR_DIAGNOSTICS ON)
add_compile_options(-Wall)
add_compile_options(-Wextra)
add_compile_options(-Wno-invalid-offsetof)
add_compile_options(-Wno-unknown-warning-option)
add_compile_options(-Wno-unused-command-line-argument)
# This warning is triggered when one accepts or returns vectors from a function (that is not marked
# with [[gnu::target(...)]]) which would have been otherwise passed in register if the current
# translation unit had been compiled with more permissive flags wrt instruction selection (i. e. if
# one adds -mavx2 to cmdline). This will never be a problem for us since we (a) never use
# different instruction selection options across ABI boundaries; (b) most of the affected functions
# are actually TU-local.
#
# Moreover, even if we somehow properly annotated all of the SIMD helpers, calling them across ABI
# (or target) boundaries would still be very dangerous because of inconsistent and bogus handling of
# [[gnu::target(...)]] across compilers. See https://github.com/llvm/llvm-project/issues/64706 and
# https://www.reddit.com/r/cpp/comments/17qowl2/comment/k8j2odi .
add_compile_options(-Wno-psabi)
add_compile_options(-fno-exceptions)
add_compile_options(-ffp-contract=off)
if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "18")
add_compile_options(-Wpadded-bitfield)
endif()
if (NOT CMAKE_HOST_SYSTEM_NAME MATCHES SerenityOS)
# FIXME: Something makes this go crazy and flag unused variables that aren't flagged as such when building with the toolchain.
# Disable -Werror for now.
add_compile_options(-Werror)
endif()
if (CMAKE_CXX_COMPILER_ID MATCHES "Clang$")
# Clang's default constexpr-steps limit is 1048576(2^20), GCC doesn't have one
add_compile_options(-fconstexpr-steps=16777216)
add_compile_options(-Wno-implicit-const-int-float-conversion)
add_compile_options(-Wno-user-defined-literals)
add_compile_options(-Wno-vla-cxx-extension)
add_compile_options(-Wno-coroutine-missing-unhandled-exception)
elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
# Only ignore expansion-to-defined for g++, clang's implementation doesn't complain about function-like macros
add_compile_options(-Wno-expansion-to-defined)
add_compile_options(-Wno-literal-suffix)
# FIXME: This warning seems useful but has too many false positives with GCC 13.
add_compile_options(-Wno-dangling-reference)
endif()
if (UNIX AND NOT APPLE AND NOT ENABLE_FUZZERS)
add_compile_options(-fno-semantic-interposition)
add_compile_options(-fvisibility-inlines-hidden)
endif()