This is the mail archive of the gdb-patches@sources.redhat.com mailing list for the GDB project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Re: [RFA]: Add misc_obstack to object files.


Daniel Berlin writes:
 > Elena Zannoni <ezannoni@cygnus.com> writes:
 > 
 > > Daniel Berlin writes:
 > > > 
 > > > This way, we stop putting things in the psymbol_obstack that don't
 > > > belong.  
 > > > 
 > > 
 > > Dan, can you elaborate a bit on why we need this?
 > Because these things don't belong in the psymbol obstack.
 > They are section offsets, not partial symbols.
 > 

Dan, I am really sorry, but still I cannot see a real reason for this
change emerging from your mail. 
You are doing this in response to some bug you saw, I assume, but what that
bug is has not been explained.

Quoting src/gdb/CONTRIBUTE:

o       Submitting Patches

        Every patch must have several pieces of information before we
        can properly evaluate it.

        A description of the bug and how your patch fixes this
        bug. A reference to a testsuite failure is very helpful. For
        new features a description of the feature and your
        implementation.

[....]
 
Supplemental information for GDB:

o       Please try to run the relevant testsuite before and after
        committing a patch

        If the contributor doesn't do it then the maintainer will.  A
        contributor might include before/after test results in their
        contribution.


o       For bug fixes, please try to include a way of
        demonstrating that the patch actually fixes something.

        The best way of doing this is to ensure that the
        testsuite contains one or more test cases that
        fail without the fix but pass with the fix.

        People are encouraged to submit patches that extend
        the testsuite.


o       Please read your patch before submitting it.

        A patch containing several unrelated changes or
        arbitrary reformats will be returned with a request
        to re-formatting / split it.


 > > Why are you removing
 > > the partial symbol table from the psymbol_objstack?
 > I'm not. At all in fact.
 > I'm specifically trying to make it so *all* that is in the
 > psymbol_obstack is the partial symbol table.
 > we've been stuffing random stuff like section offsets into the
 > psymbol_obstack, because it was handy.
 > This is wrong.
 > If we need a misc place to put info like section offsets, that isn't
 > large enough to deserve it's own obstack on it's own, then all the
 > misc stuff together should go in a misc_obstack.

Then your patch includes a diff that is unrelated.

 > 
 > >  Was this intended?
 > > There are several other things that get allocated on the
 > > psymbol_objstack, for instance look in xcoffread.c, somread.c,
 > > etc. Why just remove the section offset stuff?
 > Because I haven't gotten to the others yet.
 > And there is no harm in taking time to make sure it gets done right.
 > 

If you have a roadmap in mind, you should explain it when you submit
the patch.

 > > 
 > > If your intent was to change the allocation of the section offset
 > > information, from psymbol_obstack to misc_obstack, why not modify also
 > > the same allocations done in xcoffread.c, elfread.c, somread.c?
 > Because i haven't gotten there yet.
 > :)
 > I did it as I saw them.
 > 
 > In actuality, what i was doing was freeing the psymbol obstack when we
 > were completely done with partial symbols, and seeing what broke.
 > They never broke, so i never noticed them.
 > 
 > When i submit a large patch that does all this in one fell swoop,
 > someone would say to break it down.
 > So consider this a first step, rather than a done deal.
 > 

I am encouraging you to resubmit the patch accompanied by coherent
explanation and rationale.

Elena


 > > 
 > > Thanks
 > > Elena
 > > 
 > > 
 > > > 2001-05-27  Daniel Berlin  <dan@cgsoftware.com>
 > > > 
 > > > 	* symfile.c (default_symfile_offsets): Allocate in misc_obstack.
 > > > 	(reread_symbols): Handle misc_obstack too, and use it where
 > > > 	psymbol_obstack didn't belong. 
 > > > 	(allocate_psymtab): Ditto.
 > > > 
 > > > 	* objfiles.c (add_to_objfile_sections):  Use misc_obstack, not psymbol_obstack.
 > > > 	(build_objfile_section_table): Ditto.
 > > > 	(free_objfile): Free the misc_obstack.
 > > > 	(allocate_objfile): Setup misc_obstack too.
 > > > 
 > > > 	* objfiles.h: Add misc_obstack to object file.
 > > > 
 > > > Index: symfile.c
 > > > ===================================================================
 > > > RCS file: /cvs/src/src/gdb/symfile.c,v
 > > > retrieving revision 1.32
 > > > diff -c -3 -p -w -B -b -r1.32 symfile.c
 > > > *** symfile.c	2001/05/10 15:33:21	1.32
 > > > --- symfile.c	2001/05/29 17:27:51
 > > > *************** default_symfile_offsets (struct objfile 
 > > > *** 500,506 ****
 > > >   
 > > >     objfile->num_sections = SECT_OFF_MAX;
 > > >     objfile->section_offsets = (struct section_offsets *)
 > > > !     obstack_alloc (&objfile->psymbol_obstack, SIZEOF_SECTION_OFFSETS);
 > > >     memset (objfile->section_offsets, 0, SIZEOF_SECTION_OFFSETS);
 > > >   
 > > >     /* Now calculate offsets for section that were specified by the
 > > > --- 500,506 ----
 > > >   
 > > >     objfile->num_sections = SECT_OFF_MAX;
 > > >     objfile->section_offsets = (struct section_offsets *)
 > > > !     obstack_alloc (&objfile->misc_obstack, SIZEOF_SECTION_OFFSETS);
 > > >     memset (objfile->section_offsets, 0, SIZEOF_SECTION_OFFSETS);
 > > >   
 > > >     /* Now calculate offsets for section that were specified by the
 > > > *************** reread_symbols (void)
 > > > *** 1679,1684 ****
 > > > --- 1679,1685 ----
 > > >   
 > > >   	      /* Free the obstacks for non-reusable objfiles */
 > > >   	      free_bcache (&objfile->psymbol_cache);
 > > > + 	      obstack_free (&objfile->misc_obstack, 0);
 > > >   	      obstack_free (&objfile->psymbol_obstack, 0);
 > > >   	      obstack_free (&objfile->symbol_obstack, 0);
 > > >   	      obstack_free (&objfile->type_obstack, 0);
 > > > *************** reread_symbols (void)
 > > > *** 1704,1709 ****
 > > > --- 1705,1712 ----
 > > >   	         it is empty.  */
 > > >   	      obstack_specify_allocation (&objfile->psymbol_cache.cache, 0, 0,
 > > >   					  xmalloc, xfree);
 > > > + 	      obstack_specify_allocation (&objfile->misc_obstack, 0, 0,
 > > > + 					  xmalloc, xfree);
 > > >   	      obstack_specify_allocation (&objfile->psymbol_obstack, 0, 0,
 > > >   					  xmalloc, xfree);
 > > >   	      obstack_specify_allocation (&objfile->symbol_obstack, 0, 0,
 > > > *************** reread_symbols (void)
 > > > *** 1719,1725 ****
 > > >   	      /* We use the same section offsets as from last time.  I'm not
 > > >   	         sure whether that is always correct for shared libraries.  */
 > > >   	      objfile->section_offsets = (struct section_offsets *)
 > > > ! 		obstack_alloc (&objfile->psymbol_obstack, SIZEOF_SECTION_OFFSETS);
 > > >   	      memcpy (objfile->section_offsets, offsets, SIZEOF_SECTION_OFFSETS);
 > > >   	      objfile->num_sections = num_offsets;
 > > >   
 > > > --- 1722,1728 ----
 > > >   	      /* We use the same section offsets as from last time.  I'm not
 > > >   	         sure whether that is always correct for shared libraries.  */
 > > >   	      objfile->section_offsets = (struct section_offsets *)
 > > > ! 		obstack_alloc (&objfile->misc_obstack, SIZEOF_SECTION_OFFSETS);
 > > >   	      memcpy (objfile->section_offsets, offsets, SIZEOF_SECTION_OFFSETS);
 > > >   	      objfile->num_sections = num_offsets;
 > > >   
 > > > *************** allocate_psymtab (char *filename, struct
 > > > *** 1981,1993 ****
 > > >         objfile->free_psymtabs = psymtab->next;
 > > >       }
 > > >     else
 > > > !     psymtab = (struct partial_symtab *)
 > > > !       obstack_alloc (&objfile->psymbol_obstack,
 > > > ! 		     sizeof (struct partial_symtab));
 > > >   
 > > >     memset (psymtab, 0, sizeof (struct partial_symtab));
 > > > !   psymtab->filename = obsavestring (filename, strlen (filename),
 > > > ! 				    &objfile->psymbol_obstack);
 > > >     psymtab->symtab = NULL;
 > > >   
 > > >     /* Prepend it to the psymtab list for the objfile it belongs to.
 > > > --- 1984,1993 ----
 > > >         objfile->free_psymtabs = psymtab->next;
 > > >       }
 > > >     else
 > > > !     psymtab = (struct partial_symtab *) obstack_alloc (&objfile->misc_obstack, sizeof (struct partial_symtab));
 > > >   
 > > >     memset (psymtab, 0, sizeof (struct partial_symtab));
 > > > !   psymtab->filename = obsavestring (filename, strlen(filename), &objfile->misc_obstack);
 > > >     psymtab->symtab = NULL;
 > > >   
 > > >     /* Prepend it to the psymtab list for the objfile it belongs to.
 > > > Index: objfiles.c
 > > > ===================================================================
 > > > RCS file: /cvs/src/src/gdb/objfiles.c,v
 > > > retrieving revision 1.15
 > > > diff -c -3 -p -w -B -b -r1.15 objfiles.c
 > > > *** objfiles.c	2001/03/06 08:21:11	1.15
 > > > --- objfiles.c	2001/05/29 17:27:57
 > > > *************** add_to_objfile_sections (bfd *abfd, sec_
 > > > *** 96,102 ****
 > > >     section.ovly_mapped = 0;
 > > >     section.addr = bfd_section_vma (abfd, asect);
 > > >     section.endaddr = section.addr + bfd_section_size (abfd, asect);
 > > > !   obstack_grow (&objfile->psymbol_obstack, (char *) &section, sizeof (section));
 > > >     objfile->sections_end = (struct obj_section *) (((unsigned long) objfile->sections_end) + 1);
 > > >   }
 > > >   
 > > > --- 96,102 ----
 > > >     section.ovly_mapped = 0;
 > > >     section.addr = bfd_section_vma (abfd, asect);
 > > >     section.endaddr = section.addr + bfd_section_size (abfd, asect);
 > > > !   obstack_grow (&objfile->misc_obstack, (char *) &section, sizeof (section));
 > > >     objfile->sections_end = (struct obj_section *) (((unsigned long) objfile->sections_end) + 1);
 > > >   }
 > > >   
 > > > *************** build_objfile_section_table (struct objf
 > > > *** 121,134 ****
 > > >   {
 > > >     /* objfile->sections can be already set when reading a mapped symbol
 > > >        file.  I believe that we do need to rebuild the section table in
 > > > !      this case (we rebuild other things derived from the bfd), but we
 > > > !      can't free the old one (it's in the psymbol_obstack).  So we just
 > > > !      waste some memory.  */
 > > >   
 > > >     objfile->sections_end = 0;
 > > >     bfd_map_over_sections (objfile->obfd, add_to_objfile_sections, (char *) objfile);
 > > >     objfile->sections = (struct obj_section *)
 > > > !     obstack_finish (&objfile->psymbol_obstack);
 > > >     objfile->sections_end = objfile->sections + (unsigned long) objfile->sections_end;
 > > >     return (0);
 > > >   }
 > > > --- 121,137 ----
 > > >   {
 > > >     /* objfile->sections can be already set when reading a mapped symbol
 > > >        file.  I believe that we do need to rebuild the section table in
 > > > !      this case (we rebuild other things derived from the bfd).
 > > > !      DJB - 05-27-2001 
 > > > !      It's in the misc_obstack now, feel free to do what you need to.
 > > > !      All the stuff in objfile that was on the psymbol obstack, but didnt' belong, is in the misc obstack, which 
 > > > !      I think is all the stuff you want to blow away anyway.
 > > > !      */
 > > >   
 > > >     objfile->sections_end = 0;
 > > >     bfd_map_over_sections (objfile->obfd, add_to_objfile_sections, (char *) objfile);
 > > >     objfile->sections = (struct obj_section *)
 > > > !     obstack_finish (&objfile->misc_obstack);
 > > >     objfile->sections_end = objfile->sections + (unsigned long) objfile->sections_end;
 > > >     return (0);
 > > >   }
 > > > *************** allocate_objfile (bfd *abfd, int flags)
 > > > *** 188,193 ****
 > > > --- 191,198 ----
 > > >   	      /* Update pointers to functions to *our* copies */
 > > >   	      obstack_chunkfun (&objfile->psymbol_cache.cache, xmmalloc);
 > > >   	      obstack_freefun (&objfile->psymbol_cache.cache, mfree);
 > > > + 	      obstack_chunkfun (&objfile->misc_obstack, xmmalloc);
 > > > + 	      obstack_freefun (&objfile->misc_obstack, mfree);
 > > >   	      obstack_chunkfun (&objfile->psymbol_obstack, xmmalloc);
 > > >   	      obstack_freefun (&objfile->psymbol_obstack, mfree);
 > > >   	      obstack_chunkfun (&objfile->symbol_obstack, xmmalloc);
 > > > *************** allocate_objfile (bfd *abfd, int flags)
 > > > *** 218,223 ****
 > > > --- 223,231 ----
 > > >   	      obstack_specify_allocation_with_arg (&objfile->psymbol_cache.cache,
 > > >   						   0, 0, xmmalloc, mfree,
 > > >   						   objfile->md);
 > > > + 	      obstack_specify_allocation_with_arg (&objfile->misc_obstack,
 > > > + 						   0, 0, xmmalloc, mfree,
 > > > + 						   objfile->md);
 > > >   	      obstack_specify_allocation_with_arg (&objfile->psymbol_obstack,
 > > >   						   0, 0, xmmalloc, mfree,
 > > >   						   objfile->md);
 > > > *************** allocate_objfile (bfd *abfd, int flags)
 > > > *** 264,269 ****
 > > > --- 272,279 ----
 > > >         objfile->md = NULL;
 > > >         obstack_specify_allocation (&objfile->psymbol_cache.cache, 0, 0,
 > > >   				  xmalloc, xfree);
 > > > +       obstack_specify_allocation (&objfile->misc_obstack, 0, 0, xmalloc,
 > > > + 				  xfree);
 > > >         obstack_specify_allocation (&objfile->psymbol_obstack, 0, 0, xmalloc,
 > > >   				  xfree);
 > > >         obstack_specify_allocation (&objfile->symbol_obstack, 0, 0, xmalloc,
 > > > *************** free_objfile (struct objfile *objfile)
 > > > *** 475,480 ****
 > > > --- 485,491 ----
 > > >   	mfree (objfile->md, objfile->static_psymbols.list);
 > > >         /* Free the obstacks for non-reusable objfiles */
 > > >         free_bcache (&objfile->psymbol_cache);
 > > > +       obstack_free (&objfile->misc_obstack, 0);
 > > >         obstack_free (&objfile->psymbol_obstack, 0);
 > > >         obstack_free (&objfile->symbol_obstack, 0);
 > > >         obstack_free (&objfile->type_obstack, 0);
 > > > Index: objfiles.h
 > > > ===================================================================
 > > > RCS file: /cvs/src/src/gdb/objfiles.h,v
 > > > retrieving revision 1.8
 > > > diff -c -3 -p -w -B -b -r1.8 objfiles.h
 > > > *** objfiles.h	2001/03/06 08:21:11	1.8
 > > > --- objfiles.h	2001/05/29 17:28:00
 > > > *************** struct objfile
 > > > *** 269,274 ****
 > > > --- 269,275 ----
 > > >       /* Obstacks to hold objects that should be freed when we load a new symbol
 > > >          table from this object file. */
 > > >   
 > > > +     struct obstack misc_obstack;	/* Misc stuff */
 > > >       struct obstack psymbol_obstack;	/* Partial symbols */
 > > >       struct obstack symbol_obstack;	/* Full symbols */
 > > >       struct obstack type_obstack;	/* Types */
 > > > 
 > > > -- 
 > > > "I used to be a narrator for bad mimes.
 > > > "-Steven Wright
 > > > 
 > 
 > -- 
 > "I went into a clothes store the other day and a salesman walked
 > up to me and said, "Can I help you?"  and I said "Yeah, do you
 > got anything I like?"  He said, "What do you mean do we have
 > anything you like?"  I said, "You started this."
 > "-Steven Wright
 > 


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]