|  | // RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only \ | 
|  | // RUN:            -Wtautological-unsigned-enum-zero-compare \ | 
|  | // RUN:            -verify=unsigned,unsigned-signed %s | 
|  | // RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only \ | 
|  | // RUN:            -Wtautological-unsigned-enum-zero-compare \ | 
|  | // RUN:            -verify=unsigned-signed %s | 
|  | // RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only \ | 
|  | // RUN:            -verify=silence %s | 
|  |  | 
|  | // Okay, this is where it gets complicated. | 
|  | // Then default enum sigdness is target-specific. | 
|  | // On windows, it is signed by default. We do not want to warn in that case. | 
|  |  | 
|  | int main() { | 
|  | enum A { A_a = 0 }; | 
|  | enum A a; | 
|  | enum B { B_a = -1 }; | 
|  | enum B b; | 
|  |  | 
|  | // silence-no-diagnostics | 
|  |  | 
|  | if (a < 0) // unsigned-warning {{comparison of unsigned enum expression < 0 is always false}} | 
|  | return 0; | 
|  | if (0 >= a) | 
|  | return 0; | 
|  | if (a > 0) | 
|  | return 0; | 
|  | if (0 <= a) // unsigned-warning {{comparison of 0 <= unsigned enum expression is always true}} | 
|  | return 0; | 
|  | if (a <= 0) | 
|  | return 0; | 
|  | if (0 > a) // unsigned-warning {{comparison of 0 > unsigned enum expression is always false}} | 
|  | return 0; | 
|  | if (a >= 0) // unsigned-warning {{comparison of unsigned enum expression >= 0 is always true}} | 
|  | return 0; | 
|  | if (0 < a) | 
|  | return 0; | 
|  |  | 
|  | if (a < 0U) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}} | 
|  | return 0; | 
|  | if (0U >= a) | 
|  | return 0; | 
|  | if (a > 0U) | 
|  | return 0; | 
|  | if (0U <= a) // unsigned-signed-warning {{comparison of 0 <= unsigned enum expression is always true}} | 
|  | return 0; | 
|  | if (a <= 0U) | 
|  | return 0; | 
|  | if (0U > a) // unsigned-signed-warning {{comparison of 0 > unsigned enum expression is always false}} | 
|  | return 0; | 
|  | if (a >= 0U) // unsigned-signed-warning {{comparison of unsigned enum expression >= 0 is always true}} | 
|  | return 0; | 
|  | if (0U < a) | 
|  | return 0; | 
|  |  | 
|  | if (b < 0) | 
|  | return 0; | 
|  | if (0 >= b) | 
|  | return 0; | 
|  | if (b > 0) | 
|  | return 0; | 
|  | if (0 <= b) | 
|  | return 0; | 
|  | if (b <= 0) | 
|  | return 0; | 
|  | if (0 > b) | 
|  | return 0; | 
|  | if (b >= 0) | 
|  | return 0; | 
|  | if (0 < b) | 
|  | return 0; | 
|  |  | 
|  | if (b < 0U) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}} | 
|  | return 0; | 
|  | if (0U >= b) | 
|  | return 0; | 
|  | if (b > 0U) | 
|  | return 0; | 
|  | if (0U <= b) // unsigned-signed-warning {{comparison of 0 <= unsigned enum expression is always true}} | 
|  | return 0; | 
|  | if (b <= 0U) | 
|  | return 0; | 
|  | if (0U > b) // unsigned-signed-warning {{comparison of 0 > unsigned enum expression is always false}} | 
|  | return 0; | 
|  | if (b >= 0U) // unsigned-signed-warning {{comparison of unsigned enum expression >= 0 is always true}} | 
|  | return 0; | 
|  | if (0U < b) | 
|  | return 0; | 
|  |  | 
|  | if (a == 0) | 
|  | return 0; | 
|  | if (0 != a) | 
|  | return 0; | 
|  | if (a != 0) | 
|  | return 0; | 
|  | if (0 == a) | 
|  | return 0; | 
|  |  | 
|  | if (a == 0U) | 
|  | return 0; | 
|  | if (0U != a) | 
|  | return 0; | 
|  | if (a != 0U) | 
|  | return 0; | 
|  | if (0U == a) | 
|  | return 0; | 
|  |  | 
|  | if (b == 0) | 
|  | return 0; | 
|  | if (0 != b) | 
|  | return 0; | 
|  | if (b != 0) | 
|  | return 0; | 
|  | if (0 == b) | 
|  | return 0; | 
|  |  | 
|  | if (b == 0U) | 
|  | return 0; | 
|  | if (0U != b) | 
|  | return 0; | 
|  | if (b != 0U) | 
|  | return 0; | 
|  | if (0U == b) | 
|  | return 0; | 
|  |  | 
|  | return 1; | 
|  | } |