[Bug preprocessor/20770] New: Using -M -MT ... -MF ... with -g3 generates preprocess line to stdout

["ben at pathscale dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Found using gcc 3.4.2 on Fedora Core 3:

$ gcc -g3 -M -MT hello. -MF hello.d hello.c 
# 1 "/home/viz/src//"
$ 

The line '# 1 "/home/viz/src//"' should not be generated.

Verified that the problem still exists in 3.4.3.

$ cat hello.c
#include <stdio.h>

int main () {
   printf("Hello\n");
}
$ gcc -v -Wall -g3 -M -MT hello. -MF hello.d hello.c
Reading specs from /usr/local/lib/gcc/x86_64-unknown-linux-gnu/3.4.3/specs
Configured with: ./configure 
Thread model: posix
gcc version 3.4.3
 /usr/local/libexec/gcc/x86_64-unknown-linux-gnu/3.4.3/cc1 -E -quiet -v -M -MF hello.d -MT hello. 
-dD hello.c -mtune=k8 -Wall -fworking-directory
ignoring nonexistent directory "NONE/include"
ignoring nonexistent directory "/usr/local/lib/gcc/x86_64-unknown-linux-gnu/3.4.3/../../../../
x86_64-unknown-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/local/lib/gcc/x86_64-unknown-linux-gnu/3.4.3/include
 /usr/include
End of search list.
# 1 "/home/viz/src//"
$

Workaround: Don't use the -g3 option.

-- 
           Summary: Using -M -MT ... -MF ... with -g3 generates preprocess
                    line to stdout
           Product: gcc
           Version: 3.4.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ben at pathscale dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20770