[rfa] Re: The problem with stabs and sign extension

Daniel Jacobowitz
2001-08-08T17:15:00Z

On Wed, Aug 08, 2001 at 05:03:26PM -0700, H . J . Lu wrote:
> On Wed, Aug 08, 2001 at 04:53:59PM -0700, H . J . Lu wrote:
> > With this patch, I can do
> >
> > # gdb vmlinux
> > ...
> > (gdb) print printk
> > $1 = {int (char *)} 0x8011c5b0 <printk>
> > (gdb) list printk
> > 250 printk.c: No such file or directory.
> > in printk.c
> >
> >
>
> Here is an update.

This isn't quite the right solution, I think. In particular,

> (SWAP_SYMBOL): Removed.
> (INTERNALIZE_SYMBOL): Check sign extended vma.

are correct, but:

> * dbxread.c (COERCE32): New.
> (read_ofile_symtab): Set text_offset with COERCE32 if
> necessary.

are not. The psymtab has the wrong offsets in it if you do this.

There's actually a clear bug here, once you know where to look. A
CORE_ADDR is assigned to a long int in partial-stab.h. There's a
warning flag in GCC for this, isn't there?

Please try the patch attached.

--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer

2001-08-08 Daniel Jacobowitz <drow@mvista.com>

* partial-stab.h: valu should be a CORE_ADDR.

2001-08-08 H.J. Lu (hjl@gnu.org)

* dbxread.c (SWAP_SYMBOL): Removed.
(INTERNALIZE_SYMBOL): Check sign extended vma.

Index: partial-stab.h
===================================================================
RCS file: /cvs/src/src/gdb/partial-stab.h,v
retrieving revision 1.11
diff -u -p -r1.11 partial-stab.h
--- partial-stab.h 2001/06/01 21:17:50 1.11
+++ partial-stab.h 2001/08/09 00:11:41
@@ -201,7 +201,7 @@ switch (CUR_SYMBOL_TYPE)

case N_SO:
{
- unsigned long valu;
+ CORE_ADDR valu;
static int prev_so_symnum = -10;
static int first_so_symnum;
char *p;
Index: dbxread.c
===================================================================
RCS file: /cvs/src/src/gdb/dbxread.c,v
retrieving revision 1.19
diff -u -p -r1.19 dbxread.c
--- dbxread.c 2001/07/07 17:19:50 1.19
+++ dbxread.c 2001/08/09 00:11:41
@@ -944,22 +944,15 @@
symbuf_read += nbytes;
}

-#define SWAP_SYMBOL(symp, abfd) \
- { \
- (symp)->n_strx = bfd_h_get_32(abfd, \
- (unsigned char *)&(symp)->n_strx); \
- (symp)->n_desc = bfd_h_get_16 (abfd, \
- (unsigned char *)&(symp)->n_desc); \
- (symp)->n_value = bfd_h_get_32 (abfd, \
- (unsigned char *)&(symp)->n_value); \
- }
-
#define INTERNALIZE_SYMBOL(intern, extern, abfd) \
{ \
(intern).n_type = bfd_h_get_8 (abfd, (extern)->e_type); \
(intern).n_strx = bfd_h_get_32 (abfd, (extern)->e_strx); \
(intern).n_desc = bfd_h_get_16 (abfd, (extern)->e_desc); \
- (intern).n_value = bfd_h_get_32 (abfd, (extern)->e_value); \
+ if (bfd_get_sign_extend_vma (abfd)) \
+ (intern).n_value = bfd_h_get_signed_32 (abfd, (extern)->e_value); \
+ else \
+ (intern).n_value = bfd_h_get_32 (abfd, (extern)->e_value); \
}

/* Invariant: The symbol pointed to by symbuf_idx is the first one