$ cat test2.cc class __declspec(dllexport) __attribute__((annotate("blink_gc_plugin_ignore"))) Foo {}; $ bin/clang-cl -c test2.cc test2.cc(1,1) : error: declaration of anonymous class must be a definition class __declspec(dllexport) ^ test2.cc(1,1) : warning: declaration does not declare anything [-Wmissing-declarations] class __declspec(dllexport) ^ 1 warning and 1 error generated. In real life, this causes several cascading errors [1]. We should detect this and say "__declspec must come before __attribute__" or something like that. (Or we could allow interleaving declspecs and attributes – these are usually hidden behind macros, and having to know which macros happen to be declspecs and which are attributes is a bit annoying. On the other hand, it's nice that this enforces a consistent ordering. On the third hand, this consistent ordering isn't enforced if you have two attribute-based macros or two declspec-based ones) 1: The diagnostic we got on our bots: FAILED: ninja -t msvc -e environment.x86 -- "..\..\third_party/llvm-build/Release+Asserts/bin/clang-cl" -m32 /nologo /showIncludes /FC @obj\third_party\WebKit\Source\core\animation\webcore_shared.DeferredLegacyStyleInterpolation.obj.rsp /c ..\..\third_party\WebKit\Source\core\animation\DeferredLegacyStyleInterpolation.cpp /Foobj\third_party\WebKit\Source\core\animation\webcore_shared.DeferredLegacyStyleInterpolation.obj /Fdobj\third_party\WebKit\Source\core\webcore_shared.cc.pdb In file included from ..\..\third_party\WebKit\Source\core\animation\DeferredLegacyStyleInterpolation.cpp:10: ..\..\third_party\WebKit\Source\core/css/CSSBasicShapeValue.h(46,1) : error: declaration of anonymous class must be a definition class CORE_EXPORT GC_PLUGIN_IGNORE("535448") CSSBasicShapeValue : public CSSValue { ^ ..\..\third_party\WebKit\Source\core/css/CSSBasicShapeValue.h(46,1) : error: declaration does not declare anything [-Werror,-Wmissing-declarations] class CORE_EXPORT GC_PLUGIN_IGNORE("535448") CSSBasicShapeValue : public CSSValue { ^ ..\..\third_party\WebKit\Source\core/css/CSSBasicShapeValue.h(78,47) : error: base class has incomplete type class CSSBasicShapeCircleValue final : public CSSBasicShapeValue { ~~~~~~~^~~~~~~~~~~~~~~~~~ ..\..\third_party\WebKit\Source\core/animation/DeferredLegacyStyleInterpolation.h(15,7) : note: forward declaration of 'blink::CSSBasicShapeValue' class CSSBasicShapeValue; ^
*** This bug has been marked as a duplicate of bug 24559 ***