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Re: [patch] Fix to processing end of function stab in dbxread.c
- From: Jim Ingham <jingham at apple dot com>
- To: Daniel Jacobowitz <drow at mvista dot com>
- Cc: gdb-patches at sources dot redhat dot com
- Date: Thu, 11 Jul 2002 14:10:49 -0700
- Subject: Re: [patch] Fix to processing end of function stab in dbxread.c
Daniel,
On Thursday, July 11, 2002, at 11:42 AM, Daniel Jacobowitz wrote:
You've switched functions. That code is in read_dbx_symtab. There was
no variable in process_one_symbol by that name until quite recently.
They do have the same meaning however. That's what I meant about your
archeology being wrong. The comment that function_start_offset is
only correct for Solaris is also wrong; I can verify that it is correct
on GNU/Linux. That's not your fault, though, the comments in dbxread.c
range from mediocre to misleading. What comments referencing Solaris 2
(rather than referencing something about Sun's lame tools) often
mean is "on SVR4-ish systems".
Okay...
I judge from your example that MacOSX has resolved addresses attached
to N_SLINE stabs, but not in ending N_FUN stabs? GDB assumes that
function_start_offset applies to both of them equally (and it will be
zero if we expect both to be resolved). On GNU/Linux both N_SLINE and
final N_FUN have offsets within the function. I suspect that on some
Solaris variant N_SLINE and final N_FUN will both have resolved values.
In that case using last_function_start + valu will put us well outside
of the actual function, causing mayhem.
That's right. MacOS X's linker does fix up the SLINE stabs, but it
does what stabs.texi says to do with the end of function stabs.
It would suprise me if there were a Solaris compile/linker that does
otherwise with the end of FUN stab. After all, it seems like the
Solaris tools go out of their way to avoid having STABS that the linker
has to fix up. Also, the comment in stabs.texi says "Recent versions
of GCC will mark the end of the function with an N_FUN symbol..."
Sounds like the Solaris compilers may not have this end of function FUN
stab at all.
Would somebody with access to a Solaris box with acc on it compile a
simple program with "-g" and see if it has this stab, and if so what
its value is?
I bet the code I suggested will work fine.
Jim
--
Jim Ingham jingham@apple.com
Developer Tools - gdb
Apple Computer