qt5base-lts/cmake/QtInternalTargets.cmake
Yuhang Zhao d2a0202cda MSVC: Optimize global data to reduce binary size
Package global data in COMDAT sections for optimization.
According to the docs, this can significantly reduce the
size of the resulting binary executable.

I've tested build Qt with /Gw locally with and without
LTCG, the result shows /Gw can reduce the binary size
indeed, but not "significantly". The result also reveals
that exes can benefit much more from /Gw than dlls.
The result can be seen from the QTBUG-98894 bug report.

Microsoft Docs:
https://docs.microsoft.com/en-us/cpp/build/reference/gw-optimize-global-data?view=msvc-170

Task-number: QTBUG-98894
Change-Id: Ibce34c98e791e519d669a5fe39c0027d1459c382
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
2021-12-15 13:02:39 +08:00

324 lines
15 KiB
CMake

function(qt_internal_set_warnings_are_errors_flags target)
set(flags "")
if (CLANG AND NOT MSVC)
list(APPEND flags -Werror -Wno-error=\#warnings -Wno-error=deprecated-declarations)
elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
# using GCC
list(APPEND flags -Werror -Wno-error=cpp -Wno-error=deprecated-declarations)
# GCC prints this bogus warning, after it has inlined a lot of code
# error: assuming signed overflow does not occur when assuming that (X + c) < X is always false
list(APPEND flags -Wno-error=strict-overflow)
# GCC 7 includes -Wimplicit-fallthrough in -Wextra, but Qt is not yet free of implicit fallthroughs.
if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "7.0.0")
list(APPEND flags -Wno-error=implicit-fallthrough)
endif()
if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "9.0.0")
# GCC 9 introduced these but we are not clean for it.
list(APPEND flags -Wno-error=deprecated-copy -Wno-error=redundant-move -Wno-error=init-list-lifetime)
# GCC 9 introduced -Wformat-overflow in -Wall, but it is buggy:
list(APPEND flags -Wno-error=format-overflow)
endif()
if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "10.0.0")
# GCC 10 has a number of bugs in -Wstringop-overflow. Do not make them an error.
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92955
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94335
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101134
list(APPEND flags -Wno-error=stringop-overflow)
endif()
if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "11.0.0")
# We do mixed enum arithmetic all over the place:
list(APPEND flags -Wno-error=deprecated-enum-enum-conversion -Wno-error=deprecated-enum-float-conversion)
endif()
if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "11.0.0" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS "11.2.0")
# GCC 11.1 has a regression in the integrated preprocessor, so disable it as a workaround (QTBUG-93360)
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100796
# This in turn triggers a fallthrough warning in cborparser.c, so we disable this warning.
list(APPEND flags -no-integrated-cpp -Wno-implicit-fallthrough)
endif()
# Work-around for bug https://code.google.com/p/android/issues/detail?id=58135
if (ANDROID)
list(APPEND flags -Wno-error=literal-suffix)
endif()
elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
# Only enable for versions of MSVC that are known to work
# 1939 is Visual Studio 2022 version 17.0
if(MSVC_VERSION LESS_EQUAL 1939)
list(APPEND flags /WX)
endif()
endif()
set(warnings_are_errors_enabled_genex
"$<NOT:$<BOOL:$<TARGET_PROPERTY:QT_SKIP_WARNINGS_ARE_ERRORS>>>")
# Apprently qmake only adds -Werror to CXX and OBJCXX files, not C files. We have to do the
# same otherwise MinGW builds break when building 3rdparty\md4c\md4c.c (and probably on other
# platforms too).
set(cxx_only_genex "$<OR:$<COMPILE_LANGUAGE:CXX>,$<COMPILE_LANGUAGE:OBJCXX>>")
set(final_condition_genex "$<AND:${warnings_are_errors_enabled_genex},${cxx_only_genex}>")
set(flags_generator_expression "$<${final_condition_genex}:${flags}>")
target_compile_options("${target}" INTERFACE "${flags_generator_expression}")
endfunction()
add_library(PlatformCommonInternal INTERFACE)
add_library(Qt::PlatformCommonInternal ALIAS PlatformCommonInternal)
target_link_libraries(PlatformCommonInternal INTERFACE Platform)
add_library(PlatformModuleInternal INTERFACE)
add_library(Qt::PlatformModuleInternal ALIAS PlatformModuleInternal)
target_link_libraries(PlatformModuleInternal INTERFACE PlatformCommonInternal)
add_library(PlatformPluginInternal INTERFACE)
add_library(Qt::PlatformPluginInternal ALIAS PlatformPluginInternal)
target_link_libraries(PlatformPluginInternal INTERFACE PlatformCommonInternal)
add_library(PlatformAppInternal INTERFACE)
add_library(Qt::PlatformAppInternal ALIAS PlatformAppInternal)
target_link_libraries(PlatformAppInternal INTERFACE PlatformCommonInternal)
add_library(PlatformToolInternal INTERFACE)
add_library(Qt::PlatformToolInternal ALIAS PlatformToolInternal)
target_link_libraries(PlatformToolInternal INTERFACE PlatformAppInternal)
if(WARNINGS_ARE_ERRORS)
qt_internal_set_warnings_are_errors_flags(PlatformModuleInternal)
qt_internal_set_warnings_are_errors_flags(PlatformPluginInternal)
qt_internal_set_warnings_are_errors_flags(PlatformAppInternal)
endif()
if(WIN32)
# Needed for M_PI define. Same as mkspecs/features/qt_module.prf.
# It's set for every module being built, but it's not propagated to user apps.
target_compile_definitions(PlatformModuleInternal INTERFACE _USE_MATH_DEFINES)
endif()
if(FEATURE_largefile AND UNIX)
target_compile_definitions(PlatformCommonInternal
INTERFACE "_LARGEFILE64_SOURCE;_LARGEFILE_SOURCE")
endif()
if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" AND CMAKE_SYSTEM_NAME STREQUAL "Windows")
# Clang will otherwise show error about inline method conflicting with dllimport class attribute in tools
# (this was tested with Clang 10)
# error: 'QString::operator[]' redeclared inline; 'dllimport' attribute ignored [-Werror,-Wignored-attributes]
target_compile_options(PlatformCommonInternal INTERFACE -Wno-ignored-attributes)
endif()
target_compile_definitions(PlatformCommonInternal INTERFACE QT_NO_NARROWING_CONVERSIONS_IN_CONNECT)
target_compile_definitions(PlatformCommonInternal INTERFACE $<$<NOT:$<CONFIG:Debug>>:QT_NO_DEBUG>)
if(FEATURE_developer_build)
# This causes an ABI break on Windows, so we cannot unconditionally
# enable it. Keep it for developer builds only for now.
### Qt 7: remove the if.
target_compile_definitions(PlatformCommonInternal INTERFACE QT_STRICT_QLIST_ITERATORS)
endif()
function(qt_internal_apply_bitcode_flags target)
# See mkspecs/features/uikit/bitcode.prf
set(release_flags "-fembed-bitcode")
set(debug_flags "-fembed-bitcode-marker")
set(is_release_genex "$<NOT:$<CONFIG:Debug>>")
set(flags_genex "$<IF:${is_release_genex},${release_flags},${debug_flags}>")
set(is_enabled_genex "$<NOT:$<BOOL:$<TARGET_PROPERTY:QT_NO_BITCODE>>>")
set(bitcode_flags "$<${is_enabled_genex}:${flags_genex}>")
target_compile_options("${target}" INTERFACE ${bitcode_flags})
endfunction()
# Apple deprecated the entire OpenGL API in favor of Metal, which
# we are aware of, so silence the deprecation warnings in code.
# This does not apply to user-code, which will need to silence
# their own warnings if they use the deprecated APIs explicitly.
if(MACOS)
target_compile_definitions(PlatformCommonInternal INTERFACE GL_SILENCE_DEPRECATION)
elseif(UIKIT)
target_compile_definitions(PlatformCommonInternal INTERFACE GLES_SILENCE_DEPRECATION)
endif()
if(MSVC)
target_compile_definitions(PlatformCommonInternal INTERFACE
"_CRT_SECURE_NO_WARNINGS"
"$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,SHARED_LIBRARY>:_WINDLL>"
)
endif()
if(UIKIT)
# Do what mkspecs/features/uikit/default_pre.prf does, aka enable sse2 for
# simulator_and_device_builds.
if(FEATURE_simulator_and_device)
# Setting the definition on PlatformCommonInternal behaves slightly differently from what
# is done in qmake land. This way the define is not propagated to tests, examples, or
# user projects built with qmake, but only modules, plugins and tools.
# TODO: Figure out if this ok or not (sounds ok to me).
target_compile_definitions(PlatformCommonInternal INTERFACE QT_COMPILER_SUPPORTS_SSE2)
endif()
qt_internal_apply_bitcode_flags(PlatformCommonInternal)
endif()
if(WASM AND QT_FEATURE_sse2)
target_compile_definitions(PlatformCommonInternal INTERFACE QT_COMPILER_SUPPORTS_SSE2)
endif()
# Taken from mkspecs/common/msvc-version.conf and mkspecs/common/msvc-desktop.conf
if (MSVC)
if (MSVC_VERSION GREATER_EQUAL 1799)
target_compile_options(PlatformCommonInternal INTERFACE
-FS
-Zc:rvalueCast
-Zc:inline
)
endif()
if (MSVC_VERSION GREATER_EQUAL 1899)
target_compile_options(PlatformCommonInternal INTERFACE
-Zc:strictStrings
)
if (NOT CLANG)
target_compile_options(PlatformCommonInternal INTERFACE
-Zc:throwingNew
)
endif()
endif()
if (MSVC_VERSION GREATER_EQUAL 1909 AND NOT CLANG)
target_compile_options(PlatformCommonInternal INTERFACE
-Zc:referenceBinding
)
endif()
if (MSVC_VERSION GREATER_EQUAL 1919 AND NOT CLANG)
target_compile_options(PlatformCommonInternal INTERFACE
-Zc:externConstexpr
)
endif()
target_compile_options(PlatformCommonInternal INTERFACE -Zc:wchar_t)
target_compile_options(PlatformCommonInternal INTERFACE
$<$<NOT:$<CONFIG:Debug>>:-guard:cf -Gw>
)
target_link_options(PlatformCommonInternal INTERFACE
-DYNAMICBASE -NXCOMPAT -LARGEADDRESSAWARE
$<$<NOT:$<CONFIG:Debug>>:-OPT:REF -OPT:ICF -GUARD:CF>
)
endif()
if (GCC AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "9.2")
target_compile_options(PlatformCommonInternal INTERFACE $<$<COMPILE_LANGUAGE:CXX>:-Wsuggest-override>)
endif()
if(QT_FEATURE_force_asserts)
target_compile_definitions(PlatformCommonInternal INTERFACE QT_FORCE_ASSERTS)
endif()
if(DEFINED QT_EXTRA_DEFINES)
target_compile_definitions(PlatformCommonInternal INTERFACE ${QT_EXTRA_DEFINES})
endif()
if(DEFINED QT_EXTRA_INCLUDEPATHS)
target_include_directories(PlatformCommonInternal INTERFACE ${QT_EXTRA_INCLUDEPATHS})
endif()
if(DEFINED QT_EXTRA_LIBDIRS)
target_link_directories(PlatformCommonInternal INTERFACE ${QT_EXTRA_LIBDIRS})
endif()
if(DEFINED QT_EXTRA_FRAMEWORKPATHS AND APPLE)
list(TRANSFORM QT_EXTRA_FRAMEWORKPATHS PREPEND "-F" OUTPUT_VARIABLE __qt_fw_flags)
target_compile_options(PlatformCommonInternal INTERFACE ${__qt_fw_flags})
target_link_options(PlatformCommonInternal INTERFACE ${__qt_fw_flags})
unset(__qt_fw_flags)
endif()
if(QT_FEATURE_use_gold_linker)
target_link_options(PlatformCommonInternal INTERFACE "-fuse-ld=gold")
elseif(QT_FEATURE_use_bfd_linker)
target_link_options(PlatformCommonInternal INTERFACE "-fuse-ld=bfd")
elseif(QT_FEATURE_use_lld_linker)
target_link_options(PlatformCommonInternal INTERFACE "-fuse-ld=lld")
endif()
if(QT_FEATURE_enable_gdb_index)
target_link_options(PlatformCommonInternal INTERFACE "-Wl,--gdb-index")
endif()
if(QT_FEATURE_enable_new_dtags)
target_link_options(PlatformCommonInternal INTERFACE "-Wl,--enable-new-dtags")
endif()
function(qt_get_implicit_sse2_genex_condition out_var)
set(is_shared_lib "$<STREQUAL:$<TARGET_PROPERTY:TYPE>,SHARED_LIBRARY>")
set(is_static_lib "$<STREQUAL:$<TARGET_PROPERTY:TYPE>,STATIC_LIBRARY>")
set(is_static_qt_build "$<NOT:$<BOOL:${QT_BUILD_SHARED_LIBS}>>")
set(is_staitc_lib_during_static_qt_build "$<AND:${is_static_qt_build},${is_static_lib}>")
set(enable_sse2_condition "$<OR:${is_shared_lib},${is_staitc_lib_during_static_qt_build}>")
set(${out_var} "${enable_sse2_condition}" PARENT_SCOPE)
endfunction()
function(qt_auto_detect_implicit_sse2)
# sse2 configuration adjustment in qt_module.prf
# If the compiler supports SSE2, enable it unconditionally in all of Qt shared libraries
# (and only the libraries). This is not expected to be a problem because:
# - on Windows, sharing of libraries is uncommon
# - on Mac OS X, all x86 CPUs already have SSE2 support (we won't even reach here)
# - on Linux, the dynamic loader can find the libraries on LIBDIR/sse2/
# The last guarantee does not apply to executables and plugins, so we can't enable for them.
set(__implicit_sse2_for_qt_modules_enabled FALSE PARENT_SCOPE)
if(TEST_subarch_sse2 AND NOT TEST_arch_${TEST_architecture_arch}_subarch_sse2)
qt_get_implicit_sse2_genex_condition(enable_sse2_condition)
set(enable_sse2_genex "$<${enable_sse2_condition}:${QT_CFLAGS_SSE2}>")
target_compile_options(PlatformModuleInternal INTERFACE ${enable_sse2_genex})
set(__implicit_sse2_for_qt_modules_enabled TRUE PARENT_SCOPE)
endif()
endfunction()
qt_auto_detect_implicit_sse2()
function(qt_auto_detect_fpmath)
# fpmath configuration adjustment in qt_module.prf
set(fpmath_supported FALSE)
if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang|GNU|IntelLLVM")
set(fpmath_supported TRUE)
endif()
if(fpmath_supported AND TEST_architecture_arch STREQUAL "i386" AND __implicit_sse2_for_qt_modules_enabled)
qt_get_implicit_sse2_genex_condition(enable_sse2_condition)
set(enable_fpmath_genex "$<${enable_sse2_condition}:-mfpmath=sse>")
target_compile_options(PlatformModuleInternal INTERFACE ${enable_fpmath_genex})
endif()
endfunction()
qt_auto_detect_fpmath()
function(qt_handle_apple_app_extension_api_only)
if(APPLE)
# Build Qt libraries with -fapplication-extension. Needed to avoid linker warnings
# transformed into errors on darwin platforms.
set(flags "-fapplication-extension")
# The flags should only be applied to internal Qt libraries like modules and plugins.
# The reason why we use a custom property to apply the flags is because there's no other
# way to prevent the link options spilling out into user projects if the target that links
# against PlatformXInternal is a static library.
# The exported static library's INTERFACE_LINK_LIBRARIES property would contain
# $<LINK_ONLY:PlatformXInternal> and PlatformXInternal's INTERFACE_LINK_OPTIONS would be
# applied to a user project target.
# So to contain the spilling out of the flags, we ensure the link options are only added
# to internal Qt libraries that are marked with the property.
set(not_disabled "$<NOT:$<BOOL:$<TARGET_PROPERTY:QT_NO_APP_EXTENSION_ONLY_API>>>")
set(is_qt_internal_library "$<BOOL:$<TARGET_PROPERTY:_qt_is_internal_library>>")
set(condition "$<AND:${not_disabled},${is_qt_internal_library}>")
set(flags "$<${condition}:${flags}>")
target_compile_options(PlatformModuleInternal INTERFACE ${flags})
target_link_options(PlatformModuleInternal INTERFACE ${flags})
target_compile_options(PlatformPluginInternal INTERFACE ${flags})
target_link_options(PlatformPluginInternal INTERFACE ${flags})
endif()
endfunction()
qt_handle_apple_app_extension_api_only()