Re: GDB 5.1 on Solaris 2.8

["debashis mahata" <debashis.mahata@wipro.com>]

Hi all,

 I also hit this problem. Probably this is a problem with 
 "Sun WorkShop 6 
 update 2 C 5.3" compiler. This compiler does not generate the last back 
 slash ("/") in the first N_SO stab that represents the directory name. 
 The second N_SO is actually represents the source file name. GDB 
 identify the directory name using the last '/' as an indicator. For the 
 program

 $pwd
 /h/mahatad/DBG/GDB
 $cat a.c
 int 
 main (void) {
         int a = 1;
 }
 $

 The N_SO stab entries are - 

 With "Sun WorkShop 6 update 2 C 5.3" - 

 "/h/mahatad/DBG/GDB" ,64, 0, 0, 0
 "a.c" ,64, 0, 3, 0

 With the old version of compiler - 

 "/h/mahatad/DBG/GDB/" ,64, 0, 0, 0
 "a.c" ,64, 0, 3, 0


 It is clear that new compiler does not generate the last '/' in first 
 N_SO stab.

 Because of that GDB takes "/h/mahatad/DBG/GDB" as a file name. The 
 corresponding code is in the partial-stab.h -
   case N_SO:
    {
     ....
       p = strrchr (namestring, '/');
       if (p && *(p + 1) == '\000')
         continue; /* Simply ignore directory name SOs */

    }
 GDB is not ignoring the directory name. This requires a fix. Most 
 probably another fix is required in dbxread.c (function - 
 process_one_symbol()) for N_SO case. The corresponding code - 
     case N_SO:
         .....
     start_stabs ();
     start_symtab (name, NULL, valu);
     record_debugformat ("stabs");
       break;

 Here, the 'name' is again a directory name without the last back slash.


 I have put some fix for these two places in my local GDB source. After 
 the fix -

 $cc -V 
 cc: Sun WorkShop 6 update 2 C 5.3 2001/05/15
 $cc -g -xs a.c
 $/vob/opnpde/solaris-sparc/debug/package/00.00.00.00/bin/gdb a.out
 GNU gdb 4.18 + 02.00.01.00 (sparc64-sun-solaris2.7),
 Copyright 1998 Free Software Foundation, Inc...
 (gdb) list
 1 int 
 2 main (void) {
 3 int a = 1;
 4 }
 (gdb) 


 I found another problem with this compiler. The structures are suppose 
 to end with two consecutive ';'. GDB logic depends upon that. But this 
 compiler generate only one ';'. Just for an example - 

 For the structure 
 struct node{
         int i;
         char c;
 };

 With "Sun WorkShop 6 update 2 C 5.3" - 
 "node:T(0,21)=s8i:(0,3),0,32;c:(0,1),32,8;" ,80, 0, 8, 0

 With the old version of compiler -
 "node:T(0,21)=s8i:(0,3),0,32;c:(0,1),32,8;;" ,80, 0, 8, 0

 Again it is clear the new compiler does not generate the last ';' and 
 this will break the GDB logic in read_struct_fields() function (file: 
 stabsread.c).


 Thanks,
 debashis mahata

----- Original Message -----
From: Eli Zaretskii <eliz@is.elta.co.il>
Date: Sunday, November 25, 2001 2:08 pm
Subject: Re: GDB 5.1 on Solaris 2.8

> 
> On Sat, 24 Nov 2001, Dan Nicolaescu wrote:
> 
> >    > $ gdb a.out
> >    > gdb> list
> >    > /opt/src/devel/gdb-5.1: Is a directory.
> > 
> > Well, it works for me... But it seems that you have a newer 
> version of
> > the Sun compiler than I do:
> > 
> > cc -V
> > cc: Sun WorkShop 6 update 1 C 5.2 2000/09/11
> 
> Thanks to everyone who replied; -xs seems to be what I need.
> 
> The example above works for me as well, but I have an even older
> version of the compiler.
> 
> However, it sounds like turning on optimizations makes GDB debugging
> impossible with this compiler.  Is that expected?  Am I spoiled by
> GCC?
>