[Bug preprocessor/19290] New: -M output different with -g

[Bug preprocessor/19290] New: -M output different with -g

[papadopo at shfj dot cea dot fr]

In gcc 3.4, option -M outputs different rules when used with -g:

$ cat foo.c
#include <foo.h>
$ 
$ touch foo.h
$ 
$ gcc -M -I. foo.c
foo.o: foo.c foo.h
$ 
$ gcc -g -M -I. foo.c
# 1 "/home/user//"
foo.o: foo.c ./foo.h
$ 

This was not the case with gcc 3.3. While the output is arguably correct since
'#' is a valid comment in a Makefile, there are a few problems with this change:

1) Is it useful in any way? If not, it should be avoided since it can break things.

2) Actually it does break things. It breaks dependency generation as described
in the GNU manual or other better sources:
http://www.gnu.org/software/make/manual/html_node/make_47.html
http://make.paulandlesley.org/autodep.html

3) Also why output 'foo.h' without -g and './foo.h' with -g? This is inconsistent.

Therefore I see this as a 3.4 regression.

-- 
           Summary: -M output different with -g
           Product: gcc
           Version: 3.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: papadopo at shfj dot cea dot fr
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19290

[Bug preprocessor/19290] -M output different with -g

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-01-06 14:18 -------
I knew I had saw this before.  This is a dup of bug 17651 which is fixed 3.4.4.

*** This bug has been marked as a duplicate of 17651 ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19290