From mboxrd@z Thu Jan  1 00:00:00 1970
From: "H . J . Lu" <hjl@lucon.org>
To: gdb@sources.redhat.com
Subject: Re: The problem with stabs and sign extension
Date: Wed, 08 Aug 2001 17:03:00 -0000
Message-id: <20010808170326.A4132@lucon.org>
References: <20010808141207.A31287@nevyn.them.org> <20010808161421.A3360@lucon.org> <20010808165359.A3964@lucon.org>
X-SW-Source: 2001-08/msg00081.html

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.


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

	* dbxread.c (COERCE32): New.
	(SWAP_SYMBOL): Removed.
	(INTERNALIZE_SYMBOL): Check sign extended vma.
	(read_ofile_symtab): Set text_offset with COERCE32 if
	necessary.

--- gdb/dbxread.c.vma	Fri Jul 13 12:12:34 2001
+++ gdb/dbxread.c	Wed Aug  8 17:00:26 2001
@@ -109,6 +109,10 @@ struct symloc
 #define SYMBOL_OFFSET(p) (SYMLOC(p)->symbol_offset)
 #define STRING_OFFSET(p) (SYMLOC(p)->string_offset)
 #define FILE_STRING_OFFSET(p) (SYMLOC(p)->file_string_offset)
+
+/* Sign extension to bfd_signed_vma.  */
+#define COERCE32(x) \
+  ((bfd_signed_vma) (long) (((unsigned long) (x) ^ 0x80000000) - 0x80000000))
 
 
 /* Remember what we deduced to be the source language of this psymtab. */
@@ -946,22 +950,15 @@ fill_symbuf (bfd *sym_bfd)
   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
@@ -1685,9 +1682,13 @@ read_ofile_symtab (struct partial_symtab
   struct section_offsets *section_offsets;
 
   objfile = pst->objfile;
+  abfd = objfile->obfd;
   sym_offset = LDSYMOFF (pst);
   sym_size = LDSYMLEN (pst);
-  text_offset = pst->textlow;
+  if (bfd_get_sign_extend_vma (abfd))
+    text_offset = COERCE32 (pst->textlow);
+  else
+    text_offset = pst->textlow;
   text_size = pst->texthigh - pst->textlow;
   /* This cannot be simply objfile->section_offsets because of
      elfstab_offset_sections() which initializes the psymtab section
@@ -1701,7 +1702,6 @@ read_ofile_symtab (struct partial_symtab
   stringtab_global = DBX_STRINGTAB (objfile);
   last_source_file = NULL;
 
-  abfd = objfile->obfd;
   symfile_bfd = objfile->obfd;	/* Implicit param to next_text_symbol */
   symbuf_end = symbuf_idx = 0;