Re: [PATCH] Precheck modification time between source and object file before showing source line

[Taeung Song <treeze dot taeung at gmail dot com>]

Hi Andrew,

Sorry for late reply.

On 03/10/2017 07:25 PM, Andrew Burgess wrote:
> * Taeung Song <treeze.taeung@gmail.com> [2017-03-10 17:50:43 +0900]:
>
> > When running 'objdump -dlS',
> > if source file is more recent than object file,
> > line numbers can't match printed actual source code lines.
> > So print a warning message in the above case.
> >
> > binutils/ChangeLog:
> >
> >     * objdump.c (update_source_path): Check modification time between
> >     source and object file before opening source file.
> >     (show_line): Pass additional argument for object file name
> >     into update_source_path()
> > ---
> >  binutils/objdump.c | 14 ++++++++++++--
> >  1 file changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/binutils/objdump.c b/binutils/objdump.c
> > index 4609858..237ec45 100644
> > --- a/binutils/objdump.c
> > +++ b/binutils/objdump.c
> > @@ -1389,12 +1389,22 @@ try_print_file_open (const char *origname, const char *modname)
> >     If found, add location to print_files linked list.  */
> >
> >  static struct print_file_list *
> > -update_source_path (const char *filename)
> > +update_source_path (const char *filename, char *objname)
>
> I wonder if it would be neater to pass the bfd* pointer in here and
> then use bfd_stat below?

Okey, I'll use bfd_stat instead of just stat in v2 !

> >    struct print_file_list *p;
> >    const char *fname;
> > +  struct stat fst, ost;
> >    int i;
> >
> > +  if (stat (filename, &fst) < 0)
> > +    return NULL;
> > +  else {
>
> The '{' needs to move onto the next line, then re-indent the block below.

I got it.

> > +    if (stat (objname, &ost) < 0)
> > +      return NULL;
> > +    if (fst.st_mtime > ost.st_mtime)
> > +      warn (_("Source file is more recent than object file\n"));
>
> Seems like a good thing to warn about.  How about adding the name of
> the source file and object file to the warning?
>
> Thanks,
> Andrew

I understood!
What kind of this warning format do you prefer ?

For example, the source file is '/home/taeung/workspace/hello.c' and
the object file is '/home/taeung/workspace/a.out'

  1) just one line
objdump: Warning: Source file is more recent than object file: 
'/home/taeung/workspace/hello.c', '/home/taeung/workspace/a.out'

  2) two lines
objdump: Warning: Source file is more recent than object file:
  ('/home/taeung/workspace/hello.c', '/home/taeung/workspace/a.out')

  3) show directly the name of source file and object file
objdump: Warning: '/home/taeung/workspace/hello.c' is more recent than 
'/home/taeung/workspace/a.out'

Thanks,
Taeung

> > +  }
> > +
> >    p = try_print_file_open (filename, filename);
> >    if (p != NULL)
> >      return p;
> > @@ -1551,7 +1561,7 @@ show_line (bfd *abfd, asection *section, bfd_vma addr_offset)
> >  	{
> >  	  if (reloc)
> >  	    filename = xstrdup (filename);
> > -	  p = update_source_path (filename);
> > +	  p = update_source_path (filename, bfd_get_filename (abfd));
> >  	}
> >
> >        if (p != NULL && linenumber != p->last_line)
> > --
> > 2.7.4