1*2edb89c7SAaron Ballman // RUN: %clang_cc1 -triple i386-unknown-unknown -Eonly -verify %s 2*2edb89c7SAaron Ballman 3*2edb89c7SAaron Ballman // We warn users if they write an attribute like 4*2edb89c7SAaron Ballman // [[__clang__::fallthrough]] because __clang__ is a macro that expands to 1. 5*2edb89c7SAaron Ballman // Instead, we suggest users use [[_Clang::fallthrough]] in this situation. 6*2edb89c7SAaron Ballman // However, because __has_cpp_attribute (and __has_c_attribute) require 7*2edb89c7SAaron Ballman // expanding their argument tokens, __clang__ expands to 1 in the feature test 8*2edb89c7SAaron Ballman // macro as well. We don't currently give users a kind warning in this case, 9*2edb89c7SAaron Ballman // but we previously did not expand macros and so this would return 0. Now that 10*2edb89c7SAaron Ballman // we properly expand macros, users will now get an error about using incorrect 11*2edb89c7SAaron Ballman // syntax. 12*2edb89c7SAaron Ballman 13*2edb89c7SAaron Ballman __has_cpp_attribute(__clang__::fallthrough) // expected-error {{missing ')' after <numeric_constant>}} \ 14*2edb89c7SAaron Ballman // expected-note {{to match this '('}} \ 15*2edb89c7SAaron Ballman // expected-error {{builtin feature check macro requires a parenthesized identifier}} 16*2edb89c7SAaron Ballman 17