Re: Patch: search `directory' path for `break' files

[Elena Zannoni <ezannoni at cygnus dot com>]

Tom Tromey writes:

Tom, two things:

1. Could you please check in the cleanup of lookup_symtab_1 as a
   separate obvious fix?

2. I was about to approve your patch, which is ok, when I got curious
   about why symtab_to_filename wasn't used anywhere. Seeing it was
   introduced by Stu Grossman, I thought of gdbtk, and voila' there it
   is. Have you looked at gdbtk-cmds.c:full_lookup_symtab() ?  Does it
   do what you need? If so, could we avoid code duplication by having
   only one copy of the same function?

About partial symtabs and directory names.  I looked at how this info
gets into the symtab themselves, and it seems to happen when gdb
expands the psymtabs into symtabs. When it builds the psymtabs,
(at least in dbxread.c/partial-stab.h) it ignores the directory info:

258	      /* Some compilers (including gcc) emit a pair of initial N_SOs.
259	         The first one is a directory name; the second the file name.
260	         If pst exists, is empty, and has a filename ending in '/',
261	         we assume the previous N_SO was a directory name. */
262	
263	      p = strrchr (namestring, '/');
264	      if (p && *(p + 1) == '\000')
265		continue;		/* Simply ignore directory name SOs */


This could be changed, I think. For dwarf2, I'd have to do a little
more research. But I am sure the info is there, and modifying
read_partial_die and the partial_die info structure to add the dirname
should be doable.

Elena


 > This patch is a follow-on to this discussion:
 > 
 >     http://sources.redhat.com/ml/gdb/2001-09/msg00052.html
 > 
 > What I've done here is change lookup_symtab and lookup_partial_symtab
 > to try to use the full path when looking up a file name.  This only
 > works on systems with realpath(); it could probably be ported to other
 > systems (or a portable realpath() implementation could be found).
 > 
 > With this patch, if the file name argument to lookup_symtab is a full
 > path, we run it through realpath.  Then we search for each symtab's
 > file using the `dir' list.  If we find a match, we use it.
 > 
 > With this patch, my example:
 > 
 >     (gdb) break /home/tromey/gnu/egcs/mauve/mauve/gnu/testlet/java/text/DateFormat/Test.java:83
 > 
 > works just fine.
 > 
 > I removed some dead code from symtab.c.  I also had to add a new field
 > to struct partial_symtab.  I don't know if that is acceptable or not.
 > 
 > I built and tested this on x86 Red Hat Linux 6.2.  I ran make check
 > against the cvs head and then again with this patch applied.  There
 > were no differences.  I also tested this patch by running it against
 > my Mauve test case and less formally when debugging other gdb patches
 > I worked on today.
 > 
 > Is this ok to check in?
 > 
 > Tom
 > 
 > Index: ChangeLog
 > from  Tom Tromey  <tromey@redhat.com>
 > 
 > 	* configure, config.in: Rebuilt.
 > 	* configure.in: Check for realpath.
 > 	* defs.h (gdb_realpath): Declare.
 > 	* symtab.h (partial_symtab): Added fullname field.
 > 	* source.c (openp): Use gdb_realpath.
 > 	(forget_cached_source_info): Clear full name of each partial
 > 	symtab.
 > 	* utils.c (gdb_realpath): New function.
 > 	* symtab.c (lookup_symtab): Removed.
 > 	(lookup_symtab_1): Renamed to lookup_symtab.
 > 	(lookup_symtab): Look for real path.
 > 	(lookup_partial_symtab): Likewise.
 > 
 > Index: config.in
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/config.in,v
 > retrieving revision 1.30
 > diff -u -r1.30 config.in
 > --- config.in 2001/08/27 22:39:55 1.30
 > +++ config.in 2001/09/28 20:36:10
 > @@ -220,6 +220,9 @@
 >  /* Define if you have the putenv function.  */
 >  #undef HAVE_PUTENV
 >  
 > +/* Define if you have the realpath function.  */
 > +#undef HAVE_REALPATH
 > +
 >  /* Define if you have the sbrk function.  */
 >  #undef HAVE_SBRK
 >  
 > Index: configure
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/configure,v
 > retrieving revision 1.70
 > diff -u -r1.70 configure
 > --- configure 2001/09/06 20:59:18 1.70
 > +++ configure 2001/09/28 20:36:15
 > @@ -3582,7 +3582,7 @@
 >  fi
 >  
 >  
 > -for ac_func in bcopy btowc bzero isascii poll sbrk setpgid setpgrp \
 > +for ac_func in bcopy btowc bzero isascii poll realpath sbrk setpgid setpgrp \
 >  	sigaction sigprocmask sigsetmask
 >  do
 >  echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
 > @@ -8924,7 +8924,7 @@
 >  
 >  # Split the substitutions into bite-sized pieces for seds with
 >  # small command number limits, like on Digital OSF/1 and HP-UX.
 > -ac_max_sed_cmds=60 # Maximum number of lines to put in a sed script.
 > +ac_max_sed_cmds=90 # Maximum number of lines to put in a sed script.
 >  ac_file=1 # Number of current file.
 >  ac_beg=1 # First line for current file.
 >  ac_end=$ac_max_sed_cmds # Line after last line for current file.
 > Index: configure.in
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/configure.in,v
 > retrieving revision 1.72
 > diff -u -r1.72 configure.in
 > --- configure.in 2001/09/06 20:59:18 1.72
 > +++ configure.in 2001/09/28 20:36:16
 > @@ -131,7 +131,7 @@
 >  
 >  AC_C_CONST
 >  
 > -AC_CHECK_FUNCS(bcopy btowc bzero isascii poll sbrk setpgid setpgrp \
 > +AC_CHECK_FUNCS(bcopy btowc bzero isascii poll realpath sbrk setpgid setpgrp \
 >  	sigaction sigprocmask sigsetmask)
 >  AC_FUNC_ALLOCA
 >  AC_FUNC_VFORK
 > Index: defs.h
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/defs.h,v
 > retrieving revision 1.63
 > diff -u -r1.63 defs.h
 > --- defs.h 2001/09/07 21:33:08 1.63
 > +++ defs.h 2001/09/28 20:36:18
 > @@ -579,6 +579,8 @@
 >  extern CORE_ADDR host_pointer_to_address (void *ptr);
 >  extern void *address_to_host_pointer (CORE_ADDR addr);
 >  
 > +extern char *gdb_realpath (const char *);
 > +
 >  /* From demangle.c */
 >  
 >  extern void set_demangling_style (char *);
 > Index: source.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/source.c,v
 > retrieving revision 1.20
 > diff -u -r1.20 source.c
 > --- source.c 2001/07/17 06:41:47 1.20
 > +++ source.c 2001/09/28 20:36:35
 > @@ -234,6 +234,7 @@
 >  {
 >    register struct symtab *s;
 >    register struct objfile *objfile;
 > +  struct partial_symtab *pst;
 >  
 >    for (objfile = object_files; objfile != NULL; objfile = objfile->next)
 >      {
 > @@ -250,6 +251,15 @@
 >  	      s->fullname = NULL;
 >  	    }
 >  	}
 > +
 > +      ALL_OBJFILE_PSYMTABS (objfile, pst)
 > +      {
 > +	if (pst->fullname != NULL)
 > +	  {
 > +	    xfree (pst->fullname);
 > +	    pst->fullname = NULL;
 > +	  }
 > +      }
 >      }
 >  }
 >  
 > @@ -603,15 +613,17 @@
 >        if (fd < 0)
 >  	*filename_opened = NULL;
 >        else if (IS_ABSOLUTE_PATH (filename))
 > -	*filename_opened = savestring (filename, strlen (filename));
 > +	*filename_opened = gdb_realpath (filename);
 >        else
 >  	{
 >  	  /* Beware the // my son, the Emacs barfs, the botch that catch... */
 >  
 > -	  *filename_opened = concat (current_directory,
 > +	  char *f = concat (current_directory,
 >             IS_DIR_SEPARATOR (current_directory[strlen (current_directory) - 1])
 >  				     ? "" : SLASH_STRING,
 >  				     filename, NULL);
 > +	  *filename_opened = gdb_realpath (f);
 > +	  xfree (f);
 >  	}
 >      }
 >    /* OBSOLETE #ifdef MPW  */
 > Index: symtab.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/symtab.c,v
 > retrieving revision 1.42
 > diff -u -r1.42 symtab.c
 > --- symtab.c 2001/07/07 17:19:50 1.42
 > +++ symtab.c 2001/09/28 20:36:37
 > @@ -79,8 +79,6 @@
 >  						     const char *, int,
 >  						     namespace_enum);
 >  
 > -static struct symtab *lookup_symtab_1 (const char *);
 > -
 >  static struct symbol *lookup_symbol_aux (const char *name, const
 >  					 struct block *block, const
 >  					 namespace_enum namespace, int
 > @@ -137,20 +135,39 @@
 >     psymtabs.  *If* there is no '/' in the name, a match after a '/'
 >     in the symtab filename will also work.  */
 >  
 > -static struct symtab *
 > -lookup_symtab_1 (const char *name)
 > +struct symtab *
 > +lookup_symtab (const char *name)
 >  {
 >    register struct symtab *s;
 >    register struct partial_symtab *ps;
 >    register struct objfile *objfile;
 > +  char *real_path = NULL;
 > +
 > +  if (IS_ABSOLUTE_PATH (name))
 > +    real_path = gdb_realpath (name);
 >  
 >  got_symtab:
 >  
 >    /* First, search for an exact match */
 >  
 >    ALL_SYMTABS (objfile, s)
 > +  {
 >      if (FILENAME_CMP (name, s->filename) == 0)
 >        return s;
 > +    /* If the user gave us an absolute path, try to find the file in
 > +       this symtab and use its absolute path.  */
 > +    if (real_path != NULL)
 > +      {
 > +	char *rp = symtab_to_filename (s);
 > +	if (FILENAME_CMP (real_path, rp) == 0)
 > +	  {
 > +	    xfree (real_path);
 > +	    return s;
 > +	  }
 > +      }
 > +  }
 > +
 > +  xfree (real_path);
 >  
 >    /* Now, search for a matching tail (only if name doesn't have any dirs) */
 >  
 > @@ -188,42 +205,6 @@
 >    goto got_symtab;
 >  }
 >  
 > -/* Lookup the symbol table of a source file named NAME.  Try a couple
 > -   of variations if the first lookup doesn't work.  */
 > -
 > -struct symtab *
 > -lookup_symtab (const char *name)
 > -{
 > -  register struct symtab *s;
 > -#if 0
 > -  register char *copy;
 > -#endif
 > -
 > -  s = lookup_symtab_1 (name);
 > -  if (s)
 > -    return s;
 > -
 > -#if 0
 > -  /* This screws c-exp.y:yylex if there is both a type "tree" and a symtab
 > -     "tree.c".  */
 > -
 > -  /* If name not found as specified, see if adding ".c" helps.  */
 > -  /* Why is this?  Is it just a user convenience?  (If so, it's pretty
 > -     questionable in the presence of C++, FORTRAN, etc.).  It's not in
 > -     the GDB manual.  */
 > -
 > -  copy = (char *) alloca (strlen (name) + 3);
 > -  strcpy (copy, name);
 > -  strcat (copy, ".c");
 > -  s = lookup_symtab_1 (copy);
 > -  if (s)
 > -    return s;
 > -#endif /* 0 */
 > -
 > -  /* We didn't find anything; die.  */
 > -  return 0;
 > -}
 > -
 >  /* Lookup the partial symbol table of a source file named NAME.
 >     *If* there is no '/' in the name, a match after a '/'
 >     in the psymtab filename will also work.  */
 > @@ -233,6 +214,10 @@
 >  {
 >    register struct partial_symtab *pst;
 >    register struct objfile *objfile;
 > +  char *real_path = NULL;
 > +
 > +  if (IS_ABSOLUTE_PATH (name))
 > +    real_path = gdb_realpath (name);
 >  
 >    ALL_PSYMTABS (objfile, pst)
 >    {
 > @@ -240,7 +225,22 @@
 >        {
 >  	return (pst);
 >        }
 > +    /* If the user gave us an absolute path, try to find the file in
 > +       this symtab and use its absolute path.  */
 > +    if (real_path != NULL)
 > +      {
 > +	if (pst->fullname == NULL)
 > +	  source_full_path_of (pst->filename, &pst->fullname);
 > +	if (pst->fullname != NULL
 > +	    && FILENAME_CMP (real_path, pst->fullname) == 0)
 > +	  {
 > +	    xfree (real_path);
 > +	    return pst;
 > +	  }
 > +      }
 >    }
 > +
 > +  xfree (real_path);
 >  
 >    /* Now, search for a matching tail (only if name doesn't have any dirs) */
 >  
 > Index: symtab.h
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/symtab.h,v
 > retrieving revision 1.24
 > diff -u -r1.24 symtab.h
 > --- symtab.h 2001/07/07 17:19:50 1.24
 > +++ symtab.h 2001/09/28 20:36:39
 > @@ -959,6 +959,10 @@
 >  
 >      char *filename;
 >  
 > +    /* Full path of the source file.  NULL if not known.  */
 > +
 > +    char *fullname;
 > +
 >      /* Information about the object file from which symbols should be read.  */
 >  
 >      struct objfile *objfile;
 > Index: utils.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/utils.c,v
 > retrieving revision 1.47
 > diff -u -r1.47 utils.c
 > --- utils.c 2001/08/01 18:39:23 1.47
 > +++ utils.c 2001/09/28 20:36:43
 > @@ -2490,3 +2490,15 @@
 >    ADDRESS_TO_POINTER (builtin_type_void_data_ptr, &ptr, addr);
 >    return ptr;
 >  }
 > +
 > +char *
 > +gdb_realpath (const char *filename)
 > +{
 > +#ifdef HAVE_REALPATH
 > +  char buf[PATH_MAX];
 > +  char *rp = realpath (filename, buf);
 > +  return xstrdup (rp ? rp : filename);
 > +#else
 > +  return xstrdup (filename);
 > +#endif
 > +}