Improve CMake C/CXX/AS flag handling.

Convert the flag controlling functions to macros and omit the
FORCE argument from all the set() calls. The use of FORCE was
mainly intended to set the variable in all scopes, but using
macros instead of functions is a much cleaner method of achieving
the same goal.
This commit is contained in:
Tom Finegan 2017-12-22 16:37:43 -08:00
parent fb5ed8ebf8
commit db609de80f

View File

@ -12,7 +12,7 @@ set(DRACO_FAILED_CXX_FLAGS)
# Checks C compiler for support of $c_flag. Adds $c_flag to $CMAKE_C_FLAGS when
# the compile test passes. Caches $c_flag in $DRACO_FAILED_C_FLAGS when the test
# fails.
function (add_c_flag_if_supported c_flag)
macro (add_c_flag_if_supported c_flag)
unset(C_FLAG_FOUND CACHE)
string(FIND "${CMAKE_C_FLAGS}" "${c_flag}" C_FLAG_FOUND)
unset(C_FLAG_FAILED CACHE)
@ -23,18 +23,18 @@ function (add_c_flag_if_supported c_flag)
message("Checking C compiler flag support for: " ${c_flag})
check_c_compiler_flag("${c_flag}" C_FLAG_SUPPORTED)
if (C_FLAG_SUPPORTED)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${c_flag}" CACHE STRING "" FORCE)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${c_flag}" CACHE STRING "")
else ()
set(DRACO_FAILED_C_FLAGS "${DRACO_FAILED_C_FLAGS} ${c_flag}" CACHE STRING
"" FORCE)
"")
endif ()
endif ()
endfunction ()
endmacro ()
# Checks C++ compiler for support of $cxx_flag. Adds $cxx_flag to
# $CMAKE_CXX_FLAGS when the compile test passes. Caches $c_flag in
# $DRACO_FAILED_CXX_FLAGS when the test fails.
function (add_cxx_flag_if_supported cxx_flag)
macro (add_cxx_flag_if_supported cxx_flag)
unset(CXX_FLAG_FOUND CACHE)
string(FIND "${CMAKE_CXX_FLAGS}" "${cxx_flag}" CXX_FLAG_FOUND)
unset(CXX_FLAG_FAILED CACHE)
@ -45,25 +45,24 @@ function (add_cxx_flag_if_supported cxx_flag)
message("Checking CXX compiler flag support for: " ${cxx_flag})
check_cxx_compiler_flag("${cxx_flag}" CXX_FLAG_SUPPORTED)
if (CXX_FLAG_SUPPORTED)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${cxx_flag}" CACHE STRING ""
FORCE)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${cxx_flag}" CACHE STRING "")
else()
set(DRACO_FAILED_CXX_FLAGS "${DRACO_FAILED_CXX_FLAGS} ${cxx_flag}" CACHE
STRING "" FORCE)
STRING "")
endif ()
endif ()
endfunction ()
endmacro ()
# Convenience method for adding a flag to both the C and C++ compiler command
# lines.
function (add_compiler_flag_if_supported flag)
macro (add_compiler_flag_if_supported flag)
add_c_flag_if_supported(${flag})
add_cxx_flag_if_supported(${flag})
endfunction ()
endmacro ()
# Checks C compiler for support of $c_flag and terminates generation when
# support is not present.
function (require_c_flag c_flag update_c_flags)
macro (require_c_flag c_flag update_c_flags)
unset(C_FLAG_FOUND CACHE)
string(FIND "${CMAKE_C_FLAGS}" "${c_flag}" C_FLAG_FOUND)
@ -76,14 +75,14 @@ function (require_c_flag c_flag update_c_flags)
"${PROJECT_NAME} requires support for C flag: ${c_flag}.")
endif ()
if (update_c_flags)
set(CMAKE_C_FLAGS "${c_flag} ${CMAKE_C_FLAGS}" CACHE STRING "" FORCE)
set(CMAKE_C_FLAGS "${c_flag} ${CMAKE_C_FLAGS}" CACHE STRING "")
endif ()
endif ()
endfunction ()
endmacro ()
# Checks CXX compiler for support of $cxx_flag and terminates generation when
# support is not present.
function (require_cxx_flag cxx_flag update_cxx_flags)
macro (require_cxx_flag cxx_flag update_cxx_flags)
unset(CXX_FLAG_FOUND CACHE)
string(FIND "${CMAKE_CXX_FLAGS}" "${cxx_flag}" CXX_FLAG_FOUND)
@ -96,120 +95,117 @@ function (require_cxx_flag cxx_flag update_cxx_flags)
"${PROJECT_NAME} requires support for CXX flag: ${cxx_flag}.")
endif ()
if (update_cxx_flags)
set(CMAKE_CXX_FLAGS "${cxx_flag} ${CMAKE_CXX_FLAGS}" CACHE STRING ""
FORCE)
set(CMAKE_CXX_FLAGS "${cxx_flag} ${CMAKE_CXX_FLAGS}" CACHE STRING "")
endif ()
endif ()
endfunction ()
endmacro ()
# Checks for support of $flag by both the C and CXX compilers. Terminates
# generation when support is not present in both compilers.
function (require_compiler_flag flag update_cmake_flags)
macro (require_compiler_flag flag update_cmake_flags)
require_c_flag(${flag} ${update_cmake_flags})
require_cxx_flag(${flag} ${update_cmake_flags})
endfunction ()
endmacro ()
# Checks only non-MSVC targets for support of $c_flag and terminates generation
# when support is not present.
function (require_c_flag_nomsvc c_flag update_c_flags)
macro (require_c_flag_nomsvc c_flag update_c_flags)
if (NOT MSVC)
require_c_flag(${c_flag} ${update_c_flags})
endif ()
endfunction ()
endmacro ()
# Checks only non-MSVC targets for support of $cxx_flag and terminates
# generation when support is not present.
function (require_cxx_flag_nomsvc cxx_flag update_cxx_flags)
macro (require_cxx_flag_nomsvc cxx_flag update_cxx_flags)
if (NOT MSVC)
require_cxx_flag(${cxx_flag} ${update_cxx_flags})
endif ()
endfunction ()
endmacro ()
# Checks only non-MSVC targets for support of $flag by both the C and CXX
# compilers. Terminates generation when support is not present in both
# compilers.
function (require_compiler_flag_nomsvc flag update_cmake_flags)
macro (require_compiler_flag_nomsvc flag update_cmake_flags)
require_c_flag_nomsvc(${flag} ${update_cmake_flags})
require_cxx_flag_nomsvc(${flag} ${update_cmake_flags})
endfunction ()
endmacro ()
# Adds $preproc_def to C compiler command line (as -D$preproc_def) if not
# already present.
function (add_c_preproc_definition preproc_def)
macro (add_c_preproc_definition preproc_def)
unset(PREPROC_DEF_FOUND CACHE)
string(FIND "${CMAKE_C_FLAGS}" "${preproc_def}" PREPROC_DEF_FOUND)
if (${PREPROC_DEF_FOUND} EQUAL -1)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D${preproc_def}" CACHE STRING ""
FORCE)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D${preproc_def}" CACHE STRING "")
endif ()
endfunction ()
endmacro ()
# Adds $preproc_def to CXX compiler command line (as -D$preproc_def) if not
# already present.
function (add_cxx_preproc_definition preproc_def)
macro (add_cxx_preproc_definition preproc_def)
unset(PREPROC_DEF_FOUND CACHE)
string(FIND "${CMAKE_CXX_FLAGS}" "${preproc_def}" PREPROC_DEF_FOUND)
if (${PREPROC_DEF_FOUND} EQUAL -1)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D${preproc_def}" CACHE STRING ""
FORCE)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D${preproc_def}" CACHE STRING "")
endif ()
endfunction ()
endmacro ()
# Adds $preproc_def to C and CXX compiler command line (as -D$preproc_def) if
# not already present.
function (add_preproc_definition preproc_def)
macro (add_preproc_definition preproc_def)
add_c_preproc_definition(${preproc_def})
add_cxx_preproc_definition(${preproc_def})
endfunction ()
endmacro ()
# Adds $flag to assembler command line.
function (append_as_flag flag)
macro (append_as_flag flag)
unset(AS_FLAG_FOUND CACHE)
string(FIND "${DRACO_AS_FLAGS}" "${flag}" AS_FLAG_FOUND)
if (${AS_FLAG_FOUND} EQUAL -1)
set(DRACO_AS_FLAGS "${DRACO_AS_FLAGS} ${flag}" CACHE STRING "" FORCE)
set(DRACO_AS_FLAGS "${DRACO_AS_FLAGS} ${flag}" CACHE STRING "")
endif ()
endfunction ()
endmacro ()
# Adds $flag to the C compiler command line.
function (append_c_flag flag)
macro (append_c_flag flag)
unset(C_FLAG_FOUND CACHE)
string(FIND "${CMAKE_C_FLAGS}" "${flag}" C_FLAG_FOUND)
if (${C_FLAG_FOUND} EQUAL -1)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" CACHE STRING "" FORCE)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" CACHE STRING "")
endif ()
endfunction ()
endmacro ()
# Adds $flag to the CXX compiler command line.
function (append_cxx_flag flag)
macro (append_cxx_flag flag)
unset(CXX_FLAG_FOUND CACHE)
string(FIND "${CMAKE_CXX_FLAGS}" "${flag}" CXX_FLAG_FOUND)
if (${CXX_FLAG_FOUND} EQUAL -1)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" CACHE STRING "" FORCE)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" CACHE STRING "")
endif ()
endfunction ()
endmacro ()
# Adds $flag to the C and CXX compiler command lines.
function (append_compiler_flag flag)
macro (append_compiler_flag flag)
append_c_flag(${flag})
append_cxx_flag(${flag})
endfunction ()
endmacro ()
# Adds $flag to the executable linker command line.
function (append_exe_linker_flag flag)
macro (append_exe_linker_flag flag)
unset(LINKER_FLAG_FOUND CACHE)
string(FIND "${CMAKE_EXE_LINKER_FLAGS}" "${flag}" LINKER_FLAG_FOUND)
if (${LINKER_FLAG_FOUND} EQUAL -1)
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${flag}" CACHE STRING
"" FORCE)
"")
endif ()
endfunction ()
endmacro ()
# Adds $flag to the link flags for $target.
function (append_link_flag_to_target target flags)
@ -233,7 +229,7 @@ function (append_link_flag_to_target target flags)
endfunction ()
# Adds $flag to executable linker flags, and makes sure C/CXX builds still work.
function (require_linker_flag flag)
macro (require_linker_flag flag)
append_exe_linker_flag(${flag})
unset(c_passed)
@ -244,6 +240,6 @@ function (require_linker_flag flag)
if (NOT c_passed OR NOT cxx_passed)
message(FATAL_ERROR "Linker flag test for ${flag} failed.")
endif ()
endfunction ()
endmacro ()
endif () # DRACO_CMAKE_COMPILER_FLAGS_CMAKE_