[Bug c/14934] New: the assumed dependency target isn't always right

[Bug c/14934] New: the assumed dependency target isn't always right

[dfries at mail dot win dot org]

SpacedOut:/tmp/test$ gcc -MMD headers.h
SpacedOut:/tmp/test$ cat headers.d 
headers.o: headers.h
SpacedOut:/tmp/test$ gcc -MMD main.c
SpacedOut:/tmp/test$ cat main.d
main.o: main.c

The correct output would be,
headers.h.gch: headers.h
a.out: main.c headers.h.gch

While a.out might be arguable strace
strace -o /tmp/gcc_output -e file -f -F gcc -MMD main.c
shows that main.o was never created so it really can't be the right
target file.

The function deps_add_default_target in gcc/mkdeps.c adds .o to the
basename of whatever file that is being compiled.  Perhaps the section
of the compiler that generates the final output file should be where
the target is specified.

SpacedOut:/tmp/test$ gcc -v
Reading specs from /home/david/WorkProjects/OpenSceneGraph/DevelGcc/install/lib/gcc/i686-pc-linux-gnu/3.5.0/specs
Configured with: ../gcc_src/configure --enable-languages=c++ --prefix=/home/david/WorkProjects/OpenSceneGraph/DevelGcc/install 
--exec-prefix=/home/david/WorkProjects/OpenSceneGraph/DevelGcc/install
Thread model: posix
gcc version 3.5.0 20040412 (experimental)


header.h:
#ifndef _HEADERS_H
#define _HEADERS_H 1
const int value=32;
#endif /* _HEADERS_H */

main.c:
#include "headers.h"

int main(int argc, char ** argv)
{
        return value;
}

-- 
           Summary: the assumed dependency target isn't always right
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dfries at mail dot win dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i386-linux
  GCC host triplet: i386-linux
GCC target triplet: i386-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14934

[Bug preprocessor/14934] the assumed dependency target isn't always right

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |preprocessor


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14934

[Bug preprocessor/14934] the assumed dependency target isn't always right

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-04-13 04:27 -------
*** Bug 14935 has been marked as a duplicate of this bug. ***

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14934

[Bug preprocessor/14934] the assumed dependency target isn't always right

[tromey at gcc dot gnu dot org]

------- Comment #3 from tromey at gcc dot gnu dot org  2007-02-09 00:57 -------
I've thought about this more and I think that closing it
is best.  Please reopen (with a reason :-) if you disagree.


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14934

[Bug preprocessor/14934] the assumed dependency target isn't always right

[tromey at gcc dot gnu dot org]

------- Comment #2 from tromey at gcc dot gnu dot org  2006-12-26 00:33 -------
This is a bit weird but it is the documented behavior of -MMD.
To get a different target you must use -MT or -MQ.
My first reaction is that changing this may be unfriendly
(we don't know who, if anyone, is relying on the current behavior);
and as it follows the documentation and is also easily worked
around, we should mark this "not a bug".


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-12-26 00:33:02
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14934