[Bug preprocessor/15462] New: -M writes the filename without full path

["msharov at talentg dot com" <gcc-bugzilla at gcc dot gnu dot org>]

I have several subdirectories in my project and build files for it using the
full path name. The makefile generates automatic dependencies using -M thus:

> c++ -I ~/include -M core/address.cc
address.o: core/address.cc core/address.h
  /home/msharov/include/ustl.h \
  /home/msharov/include/ustl/uspecial.h \
  /home/msharov/include/ustl/memblock.h \
  /home/msharov/include/ustl/memlink.h \
  /home/msharov/include/ustl/cmemlink.h

and so forth. The problem is that the target name - address.o - is written
without the path, so the dependencies end up being for ./address.o rather than
core/address.o, which means that make never rebuilds the files in the
subdirectories. While I suppose it is possible to have the subdirectories as
subprojects generating .a packages which are then linked together as a
workaround, -M really should include the full path name for the target.

-- 
           Summary: -M writes the filename without full path
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: msharov at talentg dot com
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: athlon-gnu-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15462