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

[Daniel Jacobowitz <drow@mvista.com>]

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