Fwd: [patch]: Fix crash in objc and breakpoints
Kai Tietz
ktietz70@googlemail.com
Mon Feb 22 19:14:00 GMT 2010
Hello Pedro,
2010/2/22 Pedro Alves <pedro@codesourcery.com>:
> On Thursday 18 February 2010 19:32:11, Kai Tietz wrote:
>
>> * source.c (line_info): Initialize pspace by default
>> current_program_space.
>> * frame.c (find_frame_sal): Likewise.
>> * linespec.c (decode_line_2): Likewise.
>> (decode_objc): Likewise.
>>
>> Ok for apply?
>
> Sorry, not yet.
>
> The patch is mangled and I can't apply it as is,
> but I'll try to make an effort to read it anyway.
>
> Could you please, please also use (cvs) diff's -p switch
> for future patches? It makes diffs so much more readable.
> Thanks.
>
Ok, I use in general quilt for patches, but of course I can sent them
in future by using cvs -p for diff.
>>
>> Index: src/gdb/frame.c
>> ===================================================================
>> --- src.orig/gdb/frame.c 2010-01-29 16:28:43.000000000 +0100
>> +++ src/gdb/frame.c 2010-02-18 10:49:42.745803800 +0100
>> @@ -1857,6 +1857,8 @@
>> the call site is. Do not pretend to. This is jarring, but
>> we can't do much better. */
>> sal->pc = get_frame_pc (frame);
>> + /* Initialize pspace by default. */
>> + sal->pspace = current_program_space;
>>
>
> Did you try frame->pspace?
Yes, I did. But it hadn't solved the issue.
>> return;
>> }
>> Index: src/gdb/linespec.c
>> ===================================================================
>> --- src.orig/gdb/linespec.c 2010-02-18 10:41:31.000000000 +0100
>> +++ src/gdb/linespec.c 2010-02-18 10:52:50.980178800 +0100
>> @@ -513,7 +513,9 @@
>> while (i < nelts)
>> {
>> init_sal (&return_values.sals[i]); /* Initialize to zeroes.
>> */
>> + return_values.sals[i].pspace = current_program_space;
>> init_sal (&values.sals[i]);
>> + values.sals[i].pspace = current_program_space;
>> if (sym_arr[i] && SYMBOL_CLASS (sym_arr[i]) == LOC_BLOCK)
>> values.sals[i] = find_function_start_sal (sym_arr[i],
>> funfirstline);
>> i++;
>
> Sorry, I don't like these workarounds. Why was this needed?
> There must be a code path that didn't set the pspace on a
> valid sal. What was it?
>
> I think you're patching this:
>
> i = 0;
> while (i < nelts)
> {
> init_sal (&return_values.sals[i]); /* Initialize to zeroes. */
> init_sal (&values.sals[i]);
> if (sym_arr[i] && SYMBOL_CLASS (sym_arr[i]) == LOC_BLOCK)
> values.sals[i] = find_function_start_sal (sym_arr[i], funfirstline);
> i++;
> }
>
> and find_function_start_sal should be returning a sal with
> the correct pspace, so this must be about the sals that
> aren't LOC_BLOCK? What are those? Below there's this
>
> while (i < nelts)
> {
> if (sym_arr[i] && SYMBOL_CLASS (sym_arr[i]) == LOC_BLOCK)
> {
> ...
> }
> else
> printf_unfiltered (_("?HERE\n"));
> i++;
>
> Are we hitting this? Sounds like something similar to PR10966. Does
> the workaround that has been applied on the branch for this PR happen
> to fix this?
The patch in PR/10966 looks similar but didn't solved the issue, For
some of those place I added a default initialization of sal's pspace
are maybe superflous, but I saw the issue just remaining for obj-c.
I tested that the necessary patches to solve my issue are in frame.c
(find_frame_sal) and linespec.c (decode_line_2), The other seems to be
not really necessary.
>> @@ -1206,6 +1208,7 @@
>> ¤t_target);
>>
>> init_sal (&values.sals[0]);
>> + values.sals[0].pspace = current_program_space;
>> values.sals[0].pc = pc;
>> }
>> return values;
>
>
>
>> Index: src/gdb/source.c
>> ===================================================================
>> --- src.orig/gdb/source.c 2010-01-12 16:54:43.000000000 +0100
>> +++ src/gdb/source.c 2010-02-18 10:46:36.183303800 +0100
>> @@ -1467,6 +1467,7 @@
>> int i;
>>
>> init_sal (&sal); /* initialize to zeroes */
>> + sal.pspace = current_program_space; /* initialize as default. */
>
> Likewise. Isn't this a problem with the `if (arg == 0)' branch below
> only? It looks like it.
>
>>
>> if (arg == 0)
>> {
>>
>>
>
> Do you have a testcase (doesn't have to be in .exp form, just
> something I could try) for these issues yet? You seem to
> be covering different problems with the same patch.
Sadly the test-scenario for this issue is a bit big. I'll try to make
a testcase for it, but AFAI had seen it happens for me with Obj-C and
shared object files. I hope it isn't a Windows specific thing, but I
wouldn't assume so.
Kai
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