Re: The problem with stabs and sign extension

H . J . Lu
2001-08-08T17:03:00Z

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))
\f

/* 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;