implicit void arguments not checked?

[florin@xxxxxxxxx (Florin Iucha)]

Hello,

I have the following three files:

greet.h

   ---cut-here---cut-here---cut-here
   #ifndef __GREET_H__
   #define __GREET_H__

   // greet is not declared to take any arguments
   void greet();

   #endif // __GREET_H__
   ---cut-here---cut-here---cut-here

greet.c

   ---cut-here---cut-here---cut-here
   #include <stdio.h>

   void greet()
   {
         printf("Hello, Anybody!\n");
   }
   ---cut-here---cut-here---cut-here

hello.c

   ---cut-here---cut-here---cut-here
   #include "greet.h"

   int main()
   {
         // call greet with an argument
         greet("World!\n");
         return 0;
   }
   ---cut-here---cut-here---cut-here

Using gcc-4.1.1 on Debian testing/unstable:

   $ gcc greet.c hello.c
   # no error or warning

   $ gcc -Wall greet.c hello.c
   # no error or warning

   $ gcc -Wall -pedantic greet.c hello.c
   In file included from hello.c:1:
   greet.h:6:8: warning: C++ style comments are not allowed in ISO C90
   greet.h:6:8: warning: (this will be reported only once per input file)

   $ gcc -Wall -pedantic -ansi greet.c hello.c
   In file included from hello.c:1:
   greet.h:6:8: warning: extra tokens at end of #endif directive

If I change the greet declaration to "void greet(void)" I get a 
compilation error error. But it is puzzling I do not get one by
default.

1. Shouldn't gcc at least warn about greet being called with and argument
that is not present in the declaration?

2. What -W option should I use to get the warning (if it is not by
default in Wall)?

florin

-- 
If we wish to count lines of code, we should not regard them as lines
produced but as lines spent.                       -- Edsger Dijkstra

Attachment: signature.asc
Description: Digital signature