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bitcoin/cmake/module/TryAppendCXXFlags.cmake

139 lines
4.3 KiB

# Copyright (c) 2023-present The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or https://opensource.org/license/mit/.
include_guard(GLOBAL)
include(CheckCXXSourceCompiles)
#[=[
Add language-wide flags, which will be passed to all invocations of the compiler.
This includes invocations that drive compiling and those that drive linking.
Usage examples:
try_append_cxx_flags("-Wformat -Wformat-security" VAR warn_cxx_flags)
try_append_cxx_flags("-Wsuggest-override" VAR warn_cxx_flags
SOURCE "struct A { virtual void f(); }; struct B : A { void f() final; };"
)
try_append_cxx_flags("-fsanitize=${SANITIZERS}" TARGET core_interface
RESULT_VAR cxx_supports_sanitizers
)
if(NOT cxx_supports_sanitizers)
message(FATAL_ERROR "Compiler did not accept requested flags.")
endif()
try_append_cxx_flags("-Wunused-parameter" TARGET core_interface
IF_CHECK_PASSED "-Wno-unused-parameter"
)
try_append_cxx_flags("-Werror=return-type" TARGET core_interface
IF_CHECK_FAILED "-Wno-error=return-type"
SOURCE "#include <cassert>\nint f(){ assert(false); }"
)
In configuration output, this function prints a string by the following pattern:
-- Performing Test CXX_SUPPORTS_[flags]
-- Performing Test CXX_SUPPORTS_[flags] - Success
]=]
function(try_append_cxx_flags flags)
cmake_parse_arguments(PARSE_ARGV 1
TACXXF # prefix
"SKIP_LINK" # options
"TARGET;VAR;SOURCE;RESULT_VAR" # one_value_keywords
"IF_CHECK_PASSED;IF_CHECK_FAILED" # multi_value_keywords
)
set(flags_as_string "${flags}")
separate_arguments(flags)
string(MAKE_C_IDENTIFIER "${flags_as_string}" id_string)
string(TOUPPER "${id_string}" id_string)
set(source "int main() { return 0; }")
if(DEFINED TACXXF_SOURCE AND NOT TACXXF_SOURCE STREQUAL source)
set(source "${TACXXF_SOURCE}")
string(SHA256 source_hash "${source}")
string(SUBSTRING ${source_hash} 0 4 source_hash_head)
string(APPEND id_string _${source_hash_head})
endif()
# This avoids running a linker.
set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
set(CMAKE_REQUIRED_FLAGS "${flags_as_string} ${working_compiler_werror_flag}")
set(compiler_result CXX_SUPPORTS_${id_string})
check_cxx_source_compiles("${source}" ${compiler_result})
if(${compiler_result})
if(DEFINED TACXXF_IF_CHECK_PASSED)
if(DEFINED TACXXF_TARGET)
target_compile_options(${TACXXF_TARGET} INTERFACE ${TACXXF_IF_CHECK_PASSED})
endif()
if(DEFINED TACXXF_VAR)
string(STRIP "${${TACXXF_VAR}} ${TACXXF_IF_CHECK_PASSED}" ${TACXXF_VAR})
endif()
else()
if(DEFINED TACXXF_TARGET)
target_compile_options(${TACXXF_TARGET} INTERFACE ${flags})
endif()
if(DEFINED TACXXF_VAR)
string(STRIP "${${TACXXF_VAR}} ${flags_as_string}" ${TACXXF_VAR})
endif()
endif()
elseif(DEFINED TACXXF_IF_CHECK_FAILED)
if(DEFINED TACXXF_TARGET)
target_compile_options(${TACXXF_TARGET} INTERFACE ${TACXXF_IF_CHECK_FAILED})
endif()
if(DEFINED TACXXF_VAR)
string(STRIP "${${TACXXF_VAR}} ${TACXXF_IF_CHECK_FAILED}" ${TACXXF_VAR})
endif()
endif()
if(DEFINED TACXXF_VAR)
set(${TACXXF_VAR} "${${TACXXF_VAR}}" PARENT_SCOPE)
endif()
if(DEFINED TACXXF_RESULT_VAR)
set(${TACXXF_RESULT_VAR} "${${compiler_result}}" PARENT_SCOPE)
endif()
if(NOT ${compiler_result} OR TACXXF_SKIP_LINK)
return()
endif()
# This forces running a linker.
set(CMAKE_TRY_COMPILE_TARGET_TYPE EXECUTABLE)
set(CMAKE_REQUIRED_FLAGS "${flags_as_string}")
set(CMAKE_REQUIRED_LINK_OPTIONS ${working_linker_werror_flag})
set(linker_result LINKER_SUPPORTS_${id_string})
check_cxx_source_compiles("${source}" ${linker_result})
if(${linker_result})
if(DEFINED TACXXF_IF_CHECK_PASSED)
if(DEFINED TACXXF_TARGET)
target_link_options(${TACXXF_TARGET} INTERFACE ${TACXXF_IF_CHECK_PASSED})
endif()
else()
if(DEFINED TACXXF_TARGET)
target_link_options(${TACXXF_TARGET} INTERFACE ${flags})
endif()
endif()
else()
message(WARNING "'${flags_as_string}' fail(s) to link.")
endif()
endfunction()
if(MSVC)
try_append_cxx_flags("/WX /options:strict" VAR working_compiler_werror_flag SKIP_LINK)
else()
try_append_cxx_flags("-Werror" VAR working_compiler_werror_flag SKIP_LINK)
endif()