Re: Mystified by "Internal error: pc 0x89f21e10 read in psymtab, but not in symtab

Daniel Jacobowitz
2002-09-13T22:51:42Z

On Fri, Sep 13, 2002 at 03:42:16PM -0700, Earl Chew wrote:
> Daniel Jacobowitz wrote:
> > What debug information is produced by your toolchain - mdebug, I bet.
> > Mdebug support is a little on the rotting side because we don't have
> > anyone interested/willing to maintain it; and mdebug is a mighty
> > arcane format.
>
> So, I roll up my sleeves and start debugging gdb. I believe
> the compiler is producing stabs in elf. How can I check?

What version compiler and assembler are you using? And are they FSF or
WindRiver-supplied?

You should be using stabs-in-ELF, but it requires matching Binutils and
GCC. For binutils, it's enough to see that you get a .stab and
.stabstr and no .mdebug. For GCC it's harder.

> The target is VxWorks using remote serial protocol with
> segment resolution using qOffset.
>
> I put in a couple of printfs, and notice that the
> block vectors have start > end. Oops.
>
> I put another breakpoint in end_symtab, and notice that
> it's being called from read_ofile_symtab in dbxread.c. At the
> end of this function, there's a line that reads:
>
> pst->symtab = end_symtab (text_offset + text_size, objfile,
> SECT_OFF_TEXT (objfile));
>
> Looking at end_symtab in buildsym.c, I see:
>
> /* Make a block for the local symbols within. */
> finish_block (cstk->name, &local_symbols, cstk->old_blocks,
> cstk->start_addr, end_addr, objfile);
>
> Printing cstk->start_addr, I see that this is the succesfully
> relocated address (somewhere at 0x8fxxxxxx), but end_addr is
> a small number --- obviously not relocated.
>
> Patching dbxread.c
>
> pst->symtab = end_symtab (text_offset +
> text_size +
> section_offsets->offsets[SECT_OFF_TEXT (objfile)],
> objfile, SECT_OFF_TEXT (objfile));
>
> cures the problem.
>
> But I'm not sure if this patch should be applied to
> end_symtab() instead. I looked and end_symtab() is called from
> many places, and I don't have enough information to decide
> if they're right/wrong in the manner of dbxread.c.

This sounds like your GCC and binutils are out of sync, in fact.

--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer