clang/test/Sema/warn-compare-enum-types-mismatch.c

   1 // RUN: %clang_cc1 -x c -fsyntax-only -verify -Wenum-compare -Wno-unused-comparison %s
   2 // RUN: %clang_cc1 -x c++ -fsyntax-only -verify -Wenum-compare -Wno-unused-comparison %s
   3
   4 // In C enumerators (i.e enumeration constants) have type int (until C23). In
   5 // order to support diagnostics such as -Wenum-compare we pretend they have the
   6 // type of their enumeration.
   7
   8 typedef enum EnumA {
   9   A
  10 } EnumA;
  11
  12 enum EnumB {
  13   B,
  14   B1 = 1,
  15   // In C++ this comparison doesnt warn as enumerators dont have the type of
  16   // their enumeration before the closing brace. We mantain the same behavior
  17   // in C.
  18   B2 = A == B1
  19 };
  20
  21 enum {
  22   C
  23 };
  24
  25 void foo(void) {
  26   enum EnumA a = A;
  27   enum EnumB b = B;
  28   A == B;
  29   // expected-warning@-1 {{comparison of different enumeration types}}
  30   a == (B);
  31   // expected-warning@-1 {{comparison of different enumeration types}}
  32   a == b;
  33   // expected-warning@-1 {{comparison of different enumeration types}}
  34   A > B;
  35   // expected-warning@-1 {{comparison of different enumeration types}}
  36   A >= b;
  37   // expected-warning@-1 {{comparison of different enumeration types}}
  38   a > b;
  39   // expected-warning@-1 {{comparison of different enumeration types}}
  40   (A) <= ((B));
  41   // expected-warning@-1 {{comparison of different enumeration types}}
  42   a < B;
  43   // expected-warning@-1 {{comparison of different enumeration types}}
  44   a < b;
  45   // expected-warning@-1 {{comparison of different enumeration types}}
  46
  47   // In the following cases we purposefully differ from GCC and dont warn
  48   a == C;
  49   A < C;
  50   b >= C;
  51 }