clang/test/Preprocessor/warning_tests.c

   1 // RUN: %clang_cc1 -fsyntax-only %s -verify
   2 #ifndef __has_warning
   3 #error Should have __has_warning
   4 #endif
   5
   6 #if __has_warning("not valid") // expected-warning {{__has_warning expected option name}}
   7 #endif
   8
   9 // expected-warning@+2 {{Should have -Wparentheses}}
  10 #if __has_warning("-Wparentheses")
  11 #warning Should have -Wparentheses
  12 #endif
  13
  14 // expected-error@+2 {{expected string literal in '__has_warning'}}
  15 // expected-error@+1 {{missing ')'}} expected-note@+1 {{match}}
  16 #if __has_warning(-Wfoo)
  17 #endif
  18
  19 // expected-warning@+3 {{Not a valid warning flag}}
  20 #if __has_warning("-Wnot-a-valid-warning-flag-at-all")
  21 #else
  22 #warning Not a valid warning flag
  23 #endif
  24
  25 // expected-error@+1 {{missing '(' after '__has_warning'}}
  26 #if __has_warning "not valid"
  27 #endif
  28
  29 // Macro expansion does not occur in the parameter to __has_warning
  30 // (as is also expected behaviour for ordinary macros), so the
  31 // following should not expand:
  32
  33 #define MY_ALIAS "-Wparentheses"
  34
  35 // expected-error@+1 {{expected}}
  36 #if __has_warning(MY_ALIAS)
  37 #error Alias expansion not allowed
  38 #endif
  39
  40 // But deferring should expand:
  41 #define HAS_WARNING(X) __has_warning(X)
  42
  43 #if !HAS_WARNING(MY_ALIAS)
  44 #error Expansion should have occurred
  45 #endif