[CMake] Properly test if compiler supports compiler flags
https://bugs.webkit.org/show_bug.cgi?id=174490
Reviewed by Konstantin Tokarev.
.:
This turned out to be a massive pain. I didn't want to merely check options before using
them: I also wanted to organize the code to avoid setting similar flags in different places.
Right now we set a bunch of global flags in OptionsCommon.cmake, and a bunch more flags in
WEBKIT_SET_EXTRA_COMPILER_FLAGS on a per-target basis.
Setting flags per-target seems better in general, e.g. because it makes it very easy to
disable warnings for particular ThirdParty targets. But it turns out that all the flags set
on a per-target basis get passed to both the C compiler and the C++ compiler, so it's
impossible to pass C++-only flags there. That's terrible. It's possible to make the flags
language-conditional using generator expressions, but that doesn't work for the Visual
Studio backend, so we would have to drop support for that (not going to happen). The CMake
documentation suggests that C and C++ files ought to be built in separate targets to avoid
this. It's a mess, basically.
So I've wound up removing WEBKIT_SET_EXTRA_COMPILER_FLAGS and adding most of those flags to
CMAKE_C_FLAGS and CMAKE_CXX_FLAGS instead. Really the only disadvantage of this is we now
have to suppress individual warnings when building ANGLESupport in WebCore. That's not the
end of the world. The only remaining useful feature of WEBKIT_SET_EXTRA_COMPILER_FLAGS was
to add -fPIC to static library targets, but turns out CMake does that for us if we just set
the variable CMAKE_POSITION_INDEPENDENT_CODE, so we can get rid of it completely.
Of course there are also macros for setting target-specific compiler flags, which we
frequently need in order to suppress specific warnings, particularly warnings coming from
third-party libraries like ANGLE and gtest. But remember the footgun: these macros will test
the flag against only one compiler, but must work with both C and C++ compilers unless the
build target exclusively contains targets built with just one of those compilers. Yuck.
- CMakeLists.txt:
- Source/CMakeLists.txt:
- Source/PlatformGTK.cmake:
- Source/cmake/OptionsCommon.cmake:
- Source/cmake/WebKitCommon.cmake:
- Source/cmake/WebKitCompilerFlags.cmake: Added.
- Source/cmake/WebKitMacros.cmake:
Source/JavaScriptCore:
- API/tests/PingPongStackOverflowTest.cpp:
(testPingPongStackOverflow):
- API/tests/testapi.c:
- b3/testb3.cpp:
(JSC::B3::testPatchpointLotsOfLateAnys):
Source/ThirdParty:
- brotli/CMakeLists.txt:
- gtest/CMakeLists.txt:
- woff2/CMakeLists.txt:
- xdgmime/CMakeLists.txt:
Source/WebCore:
- CMakeLists.txt:
- PlatformGTK.cmake:
- PlatformWPE.cmake:
Source/WebDriver:
(WebDriver::WebDriverService::run):
- glib/SessionHostGlib.cpp:
Source/WebKit:
- CMakeLists.txt:
- PlatformGTK.cmake:
Source/WTF:
Tools:
- DumpRenderTree/TestNetscapePlugIn/CMakeLists.txt:
- MiniBrowser/gtk/CMakeLists.txt:
- TestRunnerShared/Bindings/JSWrapper.cpp:
(WTR::JSWrapper::initialize):
- TestWebKitAPI/CMakeLists.txt:
- TestWebKitAPI/PlatformGTK.cmake:
- TestWebKitAPI/Tests/WTF/CheckedArithmeticOperations.cpp:
(TestWebKitAPI::CheckedArithmeticTester::run):
- TestWebKitAPI/Tests/WebKitGLib/TestAutomationSession.cpp:
- TestWebKitAPI/Tests/WebKitGLib/TestWebExtensions.cpp:
- TestWebKitAPI/Tests/WebKitGLib/WebExtensionTest.cpp:
(formControlsAssociatedCallback):
- TestWebKitAPI/glib/CMakeLists.txt:
- TestWebKitAPI/glib/WebKitGLib/TestMain.h:
(Test::getResourcesDir):
- WebKitTestRunner/CMakeLists.txt:
- WebKitTestRunner/InjectedBundle/EventSendingController.cpp:
(WTR::menuItemClickCallback):
(WTR::staticConvertMenuItemToType):
- WebKitTestRunner/InjectedBundle/TestRunner.cpp:
(WTR::TestRunner::setUseDashboardCompatibilityMode):
- WebKitTestRunner/InjectedBundle/atk/AccessibilityNotificationHandlerAtk.cpp:
(WTR::AccessibilityNotificationHandler::disconnectAccessibilityCallbacks):
- WebKitTestRunner/InjectedBundle/atk/AccessibilityUIElementAtk.cpp:
(WTR::AccessibilityUIElement::helpText const):
(WTR::AccessibilityUIElement::attributedStringForRange):
- WebKitTestRunner/gtk/EventSenderProxyGtk.cpp:
(WTR::EventSenderProxy::updateTouchPoint):
(WTR::EventSenderProxy::releaseTouchPoint):
