[Bug preprocessor/20989] New: The -M option gives object file names without directory

["bje at safepro dot dk" <gcc-bugzilla at gcc dot gnu dot org>]

The -M preprocessor option (and -MM and similar options) strips the directory
part from the listed object file names. The documentaion for -M says:

 "Unless specified explicitly (with `-MT' or `-MQ'), the object file
  name consists of the basename of the source file with any suffix
  replaced with object file suffix."

I interpret the word "basename" in the manual text to include directories as the
basename function in GNU make does, however the actual output is without
directories:

=== Content of test/test.c ===
#include "test.h"
#include <stdio.h>
int main ()
{
    puts (GREETING);
}
=== Content of test/test.h ===
#ifndef TEST_H
#define TEST_H
#define GREETING "Hello world"
#endif
===============================
$ gcc -MM test/test.c
test.o: test/test.c test/test.h
$

I had expected the output to be: "test/test.o: test/test.c test/test.h".

-- 
           Summary: The -M option gives object file names without directory
           Product: gcc
           Version: 3.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bje at safepro dot dk
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20989