https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79300
--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> --- I've got one similar: $ cat tc.cpp #define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS throw(std::bad_alloc) MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS $ g++ tc.cpp tc.cpp:1:52: error: expected unqualified-id before ‘throw’ #define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS throw(std::bad_alloc) ^ tc.cpp:2:1: note: in expansion of macro ‘MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS’ MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS ^ With your patch for the PR, I see: ./xg++ -B. /tmp/tc.cpp /tmp/tc.cpp:1:52: error: expected unqualified-id before ‘throw’ #define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS throw(std::bad_alloc) ^~~~~ /tmp/tc.cpp:2:1: note: in expansion of macro ‘MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS’ MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS ^ and I'm wondering whether 'MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS' should be completely underlined or not? Thanks.