[PATCH] Warning for mixing enums of different types

This adds a warning when enums of different types are mixed.  I found a
handful of problems with this in my own code -- nothing that testing
could have revealed at this point, but if someone has added an extra
flag to an enum, things would have gone "boom!"

  typedef enum { A1, A2 } enumA;
  typedef enum { B1 = 10, B2 } enumB;

  static void Afunc (enumA a) { }

  int
  main (int argc, char **argv)
  {
      enumA a = A1;

      switch (A1) {
      case A1: break;
      case A2: break;
      case B1: break;  // Warn
      case B2: break;  // Warn
      default: break;
      }

      switch (1) {
      case A1: break;
      case A2: break;
      case B1: break;  // Warn
      case B2: break;  // Warn
      default: break;
      }

      switch (1) {
      case A1 ... B2: break;  // Warn
      default: break;
      }

      (void)(1 ? a : B1);  // Warn
      (void)(A1 == B1);  // Warn

      (void)(A1 << B1);  // No warning wanted

      a = B1;  // Warn

      Afunc (B1);  // Warn

      return 0;
  }

Signed-off-by: Morten Welinder <terra@gnome.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/symbol.h b/symbol.h
index 986a9cc..a773a0a 100644
--- a/symbol.h
+++ b/symbol.h
@@ -242,6 +242,13 @@ static inline int is_int_type(const struct symbol *type)
 	       type->ctype.base_type == &int_type;
 }
 
+static inline int is_enum_type(const struct symbol *type)
+{
+	if (type->type == SYM_NODE)
+		type = type->ctype.base_type;
+	return (type->type == SYM_ENUM);
+}
+
 static inline int get_sym_type(struct symbol *type)
 {
 	if (type->type == SYM_NODE)