sandbox/bugs/typedef-enum.c

#include <stdio.h>

Define an enum with name Foo

We directly define the enum type Foo using typedef similarly to the way structs are usually defined in C. This is valid C99 code and is accepted without warning by gcc, clang, and the intel C compiler. Enums are defined this way for example in the HDF5 library. Using the HDF5 library will therefore cause the warnings to appear.

typedef enum { FOO, BAR, BAZ } Foo;

Use the enum

This will produce a warning from qcc. The code for this minimal example still does the correct thing.

static void show(Foo f) {
  switch (f) {
    case FOO: puts("FOO"); break;
    case BAR: puts("BAR"); break;
    case BAZ: puts("BAZ"); break;
  }
}

int main(void) {
  show(FOO);
  show(BAR);
  show(BAZ);
}

Note: Defining the enum like this will not produce a warning:

enum Foo { FOO, BAR, BAZ };
typedef enum Foo Foo;