[OB] Fix xcoffread.c build error

[OB] Fix xcoffread.c build error

[Hui Zhu]

gcc -g -O2   -I. -I../../src/gdb -I../../src/gdb/common
-I../../src/gdb/config -DLOCALEDIR="\"/usr/local/share/locale\""
-DHAVE_CONFIG_H -I../../src/gdb/../include/opcode
-I../../src/gdb/../opcodes/.. -I../../src/gdb/../readline/.. -I../bfd
-I../../src/gdb/../bfd -I../../src/gdb/../include -I../libdecnumber
-I../../src/gdb/../libdecnumber  -I../../src/gdb/gnulib -Ignulib
-DMI_OUT=1 -DTUI=1 -DGDBTK  -Wall -Wdeclaration-after-statement
-Wpointer-arith -Wformat-nonliteral -Wno-pointer-sign -Wno-unused
-Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts
-Werror -c -o xcoffread.o -MT xcoffread.o -MMD -MP -MF
.deps/xcoffread.Tpo ../../src/gdb/xcoffread.c
cc1: warnings being treated as errors
../../src/gdb/xcoffread.c: In function 'xcoff_psymtab_to_symtab_1':
../../src/gdb/xcoffread.c:964:25: error:
'fcn_aux_saved$x_sym$x_misc$x_fsize' may be used uninitialized in this
function
make[2]: *** [xcoffread.o] Error 1
make[2]: Leaving directory `/home/teawater/gdb/cvs/ba/gdb'
make[1]: *** [all-gdb] Error 2
make[1]: Leaving directory `/home/teawater/gdb/cvs/ba'
make: *** [all] Error 2

2011-05-19  Hui Zhu  <teawater@gmail.com>

	* xcoffread.c (read_xcoff_symtab): Initialize fcn_aux_saved.
===================================================================
RCS file: /cvs/src/src/gdb/xcoffread.c,v
retrieving revision 1.87
retrieving revision 1.88
diff -u -r1.87 -r1.88
--- src/gdb/xcoffread.c	2011/04/19 14:33:09	1.87
+++ src/gdb/xcoffread.c	2011/05/19 06:54:30	1.88
@@ -961,7 +961,7 @@
   struct coff_symbol fcn_stab_saved = { 0 };

   /* fcn_cs_saved is global because process_xcoff_symbol needs it.  */
-  union internal_auxent fcn_aux_saved;
+  union internal_auxent fcn_aux_saved = main_aux;
   struct context_stack *new;

   char *filestring = " _start_ ";	/* Name of the current file.  */

Re: [OB] Fix xcoffread.c build error

[Pedro Alves]

On Thursday 19 May 2011 07:56:00, Hui Zhu wrote:
> gcc -g -O2   -I. -I../../src/gdb -I../../src/gdb/common
> -I../../src/gdb/config -DLOCALEDIR="\"/usr/local/share/locale\""
> -DHAVE_CONFIG_H -I../../src/gdb/../include/opcode
> -I../../src/gdb/../opcodes/.. -I../../src/gdb/../readline/.. -I../bfd
> -I../../src/gdb/../bfd -I../../src/gdb/../include -I../libdecnumber
> -I../../src/gdb/../libdecnumber  -I../../src/gdb/gnulib -Ignulib
> -DMI_OUT=1 -DTUI=1 -DGDBTK  -Wall -Wdeclaration-after-statement
> -Wpointer-arith -Wformat-nonliteral -Wno-pointer-sign -Wno-unused
> -Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts
> -Werror -c -o xcoffread.o -MT xcoffread.o -MMD -MP -MF
> .deps/xcoffread.Tpo ../../src/gdb/xcoffread.c
> cc1: warnings being treated as errors
> ../../src/gdb/xcoffread.c: In function 'xcoff_psymtab_to_symtab_1':
> ../../src/gdb/xcoffread.c:964:25: error:
> 'fcn_aux_saved$x_sym$x_misc$x_fsize' may be used uninitialized in this
> function
> make[2]: *** [xcoffread.o] Error 1
> make[2]: Leaving directory `/home/teawater/gdb/cvs/ba/gdb'
> make[1]: *** [all-gdb] Error 2
> make[1]: Leaving directory `/home/teawater/gdb/cvs/ba'
> make: *** [all] Error 2
> 
> 2011-05-19  Hui Zhu  <teawater@gmail.com>
> 
> 	* xcoffread.c (read_xcoff_symtab): Initialize fcn_aux_saved.
> ===================================================================
> RCS file: /cvs/src/src/gdb/xcoffread.c,v
> retrieving revision 1.87
> retrieving revision 1.88
> diff -u -r1.87 -r1.88
> --- src/gdb/xcoffread.c	2011/04/19 14:33:09	1.87
> +++ src/gdb/xcoffread.c	2011/05/19 06:54:30	1.88
> @@ -961,7 +961,7 @@
>    struct coff_symbol fcn_stab_saved = { 0 };
> 
>    /* fcn_cs_saved is global because process_xcoff_symbol needs it.  */
> -  union internal_auxent fcn_aux_saved;
> +  union internal_auxent fcn_aux_saved = main_aux;

Hmm?  Initializing fcn_aux_saved with the also uninitialized 
main_aux makes the warning go away?

This appears to be hiding a real bug.

>    struct context_stack *new;
> 
>    char *filestring = " _start_ ";	/* Name of the current file.  */
> 

-- 
Pedro Alves

Re: [OB] Fix xcoffread.c build error

[Hui Zhu]

On Thu, May 19, 2011 at 17:59, Pedro Alves <pedro@codesourcery.com> wrote:
> On Thursday 19 May 2011 07:56:00, Hui Zhu wrote:
>> gcc -g -O2   -I. -I../../src/gdb -I../../src/gdb/common
>> -I../../src/gdb/config -DLOCALEDIR="\"/usr/local/share/locale\""
>> -DHAVE_CONFIG_H -I../../src/gdb/../include/opcode
>> -I../../src/gdb/../opcodes/.. -I../../src/gdb/../readline/.. -I../bfd
>> -I../../src/gdb/../bfd -I../../src/gdb/../include -I../libdecnumber
>> -I../../src/gdb/../libdecnumber  -I../../src/gdb/gnulib -Ignulib
>> -DMI_OUT=1 -DTUI=1 -DGDBTK  -Wall -Wdeclaration-after-statement
>> -Wpointer-arith -Wformat-nonliteral -Wno-pointer-sign -Wno-unused
>> -Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts
>> -Werror -c -o xcoffread.o -MT xcoffread.o -MMD -MP -MF
>> .deps/xcoffread.Tpo ../../src/gdb/xcoffread.c
>> cc1: warnings being treated as errors
>> ../../src/gdb/xcoffread.c: In function 'xcoff_psymtab_to_symtab_1':
>> ../../src/gdb/xcoffread.c:964:25: error:
>> 'fcn_aux_saved$x_sym$x_misc$x_fsize' may be used uninitialized in this
>> function
>> make[2]: *** [xcoffread.o] Error 1
>> make[2]: Leaving directory `/home/teawater/gdb/cvs/ba/gdb'
>> make[1]: *** [all-gdb] Error 2
>> make[1]: Leaving directory `/home/teawater/gdb/cvs/ba'
>> make: *** [all] Error 2
>>
>> 2011-05-19  Hui Zhu  <teawater@gmail.com>
>>
>>       * xcoffread.c (read_xcoff_symtab): Initialize fcn_aux_saved.
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/xcoffread.c,v
>> retrieving revision 1.87
>> retrieving revision 1.88
>> diff -u -r1.87 -r1.88
>> --- src/gdb/xcoffread.c       2011/04/19 14:33:09     1.87
>> +++ src/gdb/xcoffread.c       2011/05/19 06:54:30     1.88
>> @@ -961,7 +961,7 @@
>>    struct coff_symbol fcn_stab_saved = { 0 };
>>
>>    /* fcn_cs_saved is global because process_xcoff_symbol needs it.  */
>> -  union internal_auxent fcn_aux_saved;
>> +  union internal_auxent fcn_aux_saved = main_aux;
>
> Hmm?  Initializing fcn_aux_saved with the also uninitialized
> main_aux makes the warning go away?
>
> This appears to be hiding a real bug.
>
>>    struct context_stack *new;
>>
>>    char *filestring = " _start_ ";    /* Name of the current file.  */
>>
>
> --
> Pedro Alves
>

I am sorry that I just make it can be build but looks didn't fix it.

I checked all of this function:
  while (symnum < max_symnum)
    {
      if ((cs->c_sclass == C_EXT || cs->c_sclass == C_HIDEXT)
	  && cs->c_naux == 1)
	{
	  bfd_coff_swap_aux_in (abfd, raw_auxptr, cs->c_type, cs->c_sclass,
				0, cs->c_naux, &main_aux);

	    case XTY_LD:
		case XMC_PR:
		  fcn_aux_saved = main_aux;


	case C_FCN:
	  else if (strcmp (cs->c_name, ".ef") == 0)
	      finish_block (new->name, &local_symbols, new->old_blocks,
			    new->start_addr,
			    (fcn_cs_saved.c_value
			     + fcn_aux_saved.x_sym.x_misc.x_fsize
			     + ANOFFSET (objfile->section_offsets,
					 SECT_OFF_TEXT (objfile))),
			    objfile);


Not sure I can fixed it or not.  What about add a "fcn_aux_saved =
main_aux;" after "bfd_coff_swap_aux_in"?

Thanks,
Hui

Re: [OB] Fix xcoffread.c build error

[Pedro Alves]

On Friday 20 May 2011 06:12:11, Hui Zhu wrote:
> On Thu, May 19, 2011 at 17:59, Pedro Alves <pedro@codesourcery.com> wrote:
> > On Thursday 19 May 2011 07:56:00, Hui Zhu wrote:
> >> gcc -g -O2   -I. -I../../src/gdb -I../../src/gdb/common
> >> -I../../src/gdb/config -DLOCALEDIR="\"/usr/local/share/locale\""
> >> -DHAVE_CONFIG_H -I../../src/gdb/../include/opcode
> >> -I../../src/gdb/../opcodes/.. -I../../src/gdb/../readline/.. -I../bfd
> >> -I../../src/gdb/../bfd -I../../src/gdb/../include -I../libdecnumber
> >> -I../../src/gdb/../libdecnumber  -I../../src/gdb/gnulib -Ignulib
> >> -DMI_OUT=1 -DTUI=1 -DGDBTK  -Wall -Wdeclaration-after-statement
> >> -Wpointer-arith -Wformat-nonliteral -Wno-pointer-sign -Wno-unused
> >> -Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts
> >> -Werror -c -o xcoffread.o -MT xcoffread.o -MMD -MP -MF
> >> .deps/xcoffread.Tpo ../../src/gdb/xcoffread.c
> >> cc1: warnings being treated as errors
> >> ../../src/gdb/xcoffread.c: In function 'xcoff_psymtab_to_symtab_1':
> >> ../../src/gdb/xcoffread.c:964:25: error:
> >> 'fcn_aux_saved$x_sym$x_misc$x_fsize' may be used uninitialized in this
> >> function
> >> make[2]: *** [xcoffread.o] Error 1
> >> make[2]: Leaving directory `/home/teawater/gdb/cvs/ba/gdb'
> >> make[1]: *** [all-gdb] Error 2
> >> make[1]: Leaving directory `/home/teawater/gdb/cvs/ba'
> >> make: *** [all] Error 2
> >>
> >> 2011-05-19  Hui Zhu  <teawater@gmail.com>
> >>
> >>       * xcoffread.c (read_xcoff_symtab): Initialize fcn_aux_saved.
> >> ===================================================================
> >> RCS file: /cvs/src/src/gdb/xcoffread.c,v
> >> retrieving revision 1.87
> >> retrieving revision 1.88
> >> diff -u -r1.87 -r1.88
> >> --- src/gdb/xcoffread.c       2011/04/19 14:33:09     1.87
> >> +++ src/gdb/xcoffread.c       2011/05/19 06:54:30     1.88
> >> @@ -961,7 +961,7 @@
> >>    struct coff_symbol fcn_stab_saved = { 0 };
> >>
> >>    /* fcn_cs_saved is global because process_xcoff_symbol needs it.  */
> >> -  union internal_auxent fcn_aux_saved;
> >> +  union internal_auxent fcn_aux_saved = main_aux;
> >
> > Hmm?  Initializing fcn_aux_saved with the also uninitialized
> > main_aux makes the warning go away?
> >
> > This appears to be hiding a real bug.
> >
> >>    struct context_stack *new;
> >>
> >>    char *filestring = " _start_ ";    /* Name of the current file.  */
> >>
> >
> > --
> > Pedro Alves
> >
> 
> I am sorry that I just make it can be build but looks didn't fix it.
> 
> I checked all of this function:
>   while (symnum < max_symnum)
>     {
>       if ((cs->c_sclass == C_EXT || cs->c_sclass == C_HIDEXT)
> 	  && cs->c_naux == 1)
> 	{
> 	  bfd_coff_swap_aux_in (abfd, raw_auxptr, cs->c_type, cs->c_sclass,
> 				0, cs->c_naux, &main_aux);
> 
> 	    case XTY_LD:
> 		case XMC_PR:
> 		  fcn_aux_saved = main_aux;
> 
> 
> 	case C_FCN:
> 	  else if (strcmp (cs->c_name, ".ef") == 0)
> 	      finish_block (new->name, &local_symbols, new->old_blocks,
> 			    new->start_addr,
> 			    (fcn_cs_saved.c_value
> 			     + fcn_aux_saved.x_sym.x_misc.x_fsize
> 			     + ANOFFSET (objfile->section_offsets,
> 					 SECT_OFF_TEXT (objfile))),
> 			    objfile);
> 
> 
> Not sure I can fixed it or not.  What about add a "fcn_aux_saved =
> main_aux;" after "bfd_coff_swap_aux_in"?

It that were possible, then why would we need fcn_aux_saved
at all?  This is a bit hard to follow without a
file to test with, but ISTM that fcn_aux_saved is needed because
main_aux no longer contains what we need at the time time
fcn_aux_saved is used (that is, we've moved to
another symbol/aux).

Does gcc still output a warning with this for you?

Maybe Tristian can check if this doesn't break something?

(I suppose fcn_aux_saved and a bunch other locals should be
cleared somewhere, most likely after finish_block, or
where we do the complaints.)

-- 
Pedro Alves

2011-05-24  Pedro Alves  <pedro@codesourcery.com>

	gdb/
	* xcoffread.c (read_xcoff_symtab): Don't initialize fcn_aux_saved
	with main_aux.  New local fcn_aux_saved_p.  Set it when
	fcn_aux_saved is set.  When finishing a function block, if
	fcn_aux_saved_p is false, ignore the function.

---
 gdb/xcoffread.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Index: src/gdb/xcoffread.c
===================================================================
--- src.orig/gdb/xcoffread.c	2011-05-19 18:57:19.000000000 +0100
+++ src/gdb/xcoffread.c	2011-05-24 16:44:17.298753682 +0100
@@ -961,7 +961,8 @@ read_xcoff_symtab (struct partial_symtab
   struct coff_symbol fcn_stab_saved = { 0 };
 
   /* fcn_cs_saved is global because process_xcoff_symbol needs it.  */
-  union internal_auxent fcn_aux_saved = main_aux;
+  union internal_auxent fcn_aux_saved;
+  int fcn_aux_saved_p = 0;
   struct context_stack *new;
 
   char *filestring = " _start_ ";	/* Name of the current file.  */
@@ -1195,6 +1196,7 @@ read_xcoff_symtab (struct partial_symtab
 		     when `.bf' is seen.  */
 		  fcn_cs_saved = *cs;
 		  fcn_aux_saved = main_aux;
+		  fcn_aux_saved_p = 1;
 		  continue;
 
 		case XMC_GL:
@@ -1329,6 +1331,13 @@ read_xcoff_symtab (struct partial_symtab
 		{
 		  ef_complaint (cs->c_symnum);
 		  within_function = 0;
+		  break;
+		}
+
+	      if (!fcn_aux_saved_p)
+		{
+		  ef_complaint (cs->c_symnum);
+		  within_function = 0;
 		  break;
 		}
 

Re: [OB] Fix xcoffread.c build error

[Pedro Alves]

On Tuesday 24 May 2011 17:27:43, Pedro Alves wrote:
> Maybe Tristian can check if this doesn't break something?

Whoops, apologies for typoing your name.

-- 
Pedro Alves

Re: [OB] Fix xcoffread.c build error

[Tristan Gingold]

On May 24, 2011, at 6:27 PM, Pedro Alves wrote:

[...]

> It that were possible, then why would we need fcn_aux_saved
> at all?  This is a bit hard to follow without a
> file to test with, but ISTM that fcn_aux_saved is needed because
> main_aux no longer contains what we need at the time time
> fcn_aux_saved is used (that is, we've moved to
> another symbol/aux).
> 
> Does gcc still output a warning with this for you?
> 
> Maybe Tristian can check if this doesn't break something?

I can do a sanity check if you need (please confirm), but a full regression (using AdaCore testsuite)
will be done when Joel updates our head branch.

> (I suppose fcn_aux_saved and a bunch other locals should be
> cleared somewhere, most likely after finish_block, or
> where we do the complaints.)

Your change looks safe, but as fcn_aux_saved_p is never cleared, it will catch
only if the missing PR symbol is the first one.

IMHO (and just IMHO), to get rid of the warning why not saving only the fsize field (instead of
the whole aux entry) and initialize to 0 ?

Tristan.

Re: [OB] Fix xcoffread.c build error

[Joel Brobecker]

> I can do a sanity check if you need (please confirm), but a full
> regression (using AdaCore testsuite) will be done when Joel updates
> our head branch.

I was planning on doing that early next week (a bit tied up this
week), but I can do that tomorrow if that helps. Just let me know.

-- 
Joel