[PATCH]: bfd: Fix uninitialized data warnings on AIX

[PATCH]: bfd: Fix uninitialized data warnings on AIX

[Sam Thursfield]

[-- Attachment #1: Type: text/plain, Size: 290 bytes --]

Hello

I hit a bunch of compile warnings compiling on powerpc-ibm-aix7.2.0.0 
using GCC 6.3.0.

Attached is a patch which fixes them. I've also attached the compile 
warnings that I see without the patch.

Thanks
Sam

-- 
Sam Thursfield, Codethink Ltd.
Office telephone: +44 161 236 5575



[-- Attachment #2: bfd-aix-warnings.txt --]
[-- Type: text/plain, Size: 5389 bytes --]

gmake[2]: Entering directory '/home/code/src/binutils-gdb/bfd'
/bin/sh ./libtool --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -DAIX_5_CORE -DAIX_CORE_DUMPX_CORE -DAIX_CORE  -DAIX_WEAK_SUPPORT  -I. -I. -I./../include  -DHAVE_rs6000_xcoff_vec -DHAVE_rs6000_xcoff64_aix_vec -DHAVE_plugin_vec -I./../intl -DBINDIR='"/opt/binutils-git/bin"'  -W -Wall -Wstrict-prototypes -Wmissing-prototypes -Wshadow -Wstack-usage=262144 -Werror -I./../zlib -g -O2 -MT rs6000-core.lo -MD -MP -MF .deps/rs6000-core.Tpo -c -o rs6000-core.lo rs6000-core.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -DAIX_5_CORE -DAIX_CORE_DUMPX_CORE -DAIX_CORE -DAIX_WEAK_SUPPORT -I. -I. -I./../include -DHAVE_rs6000_xcoff_vec -DHAVE_rs6000_xcoff64_aix_vec -DHAVE_plugin_vec -I./../intl -DBINDIR=\"/opt/binutils-git/bin\" -W -Wall -Wstrict-prototypes -Wmissing-prototypes -Wshadow -Wstack-usage=262144 -Werror -I./../zlib -g -O2 -MT rs6000-core.lo -MD -MP -MF .deps/rs6000-core.Tpo -c rs6000-core.c -o rs6000-core.o
rs6000-core.c: In function 'rs6000coff_core_p':
rs6000-core.c:325:14: error: 'vminfo_addr' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   asect->vma = vma;
   ~~~~~~~~~~~^~~~~
rs6000-core.c:654:14: note: 'vminfo_addr' was declared here
      bfd_vma vminfo_addr;
              ^~~~~~~~~~~
rs6000-core.c:326:18: error: 'vminfo_offset' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   asect->filepos = filepos;
   ~~~~~~~~~~~~~~~^~~~~~~~~
rs6000-core.c:653:15: note: 'vminfo_offset' was declared here
      file_ptr vminfo_offset;
               ^~~~~~~~~~~~~
rs6000-core.c:324:15: error: 'vminfo_size' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   asect->size = size;
   ~~~~~~~~~~~~^~~~~~
rs6000-core.c:652:20: note: 'vminfo_size' was declared here
      bfd_size_type vminfo_size;
                    ^~~~~~~~~~~
rs6000-core.c:646:6: error: 'c_vmm' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  if (bfd_seek (abfd, c_vmm, SEEK_SET) != 0)
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rs6000-core.c:326:18: error: 'c_data' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   asect->filepos = filepos;
   ~~~~~~~~~~~~~~~^~~~~~~~~
rs6000-core.c:564:14: note: 'c_data' was declared here
     file_ptr c_data, c_vmm;
              ^~~~~~
rs6000-core.c:649:2: error: 'c_vmregions' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  for (i = 0; i < c_vmregions; i++)
  ^~~
rs6000-core.c:324:15: error: 'c_datasize' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   asect->size = size;
   ~~~~~~~~~~~~^~~~~~
rs6000-core.c:563:19: note: 'c_datasize' was declared here
     bfd_size_type c_datasize, c_vmregions;
                   ^~~~~~~~~~
rs6000-core.c:511:8: error: 'c_stackend' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   if (!make_bfd_asection (abfd, ".stack",
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS,
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      c_size, c_stackend - c_size, c_stack))
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rs6000-core.c:324:15: error: 'c_lsize' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   asect->size = size;
   ~~~~~~~~~~~~^~~~~~
rs6000-core.c:346:36: note: 'c_lsize' was declared here
   bfd_size_type c_size, c_regsize, c_lsize;
                                    ^~~~~~~
rs6000-core.c:511:8: error: 'c_size' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   if (!make_bfd_asection (abfd, ".stack",
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS,
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      c_size, c_stackend - c_size, c_stack))
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rs6000-core.c:463:4: error: 'c_loader' may be used uninitialized in this function [-Werror=maybe-uninitialized]
       && (
          ~
 #ifndef BFD64
 ~~~~~~~~~~~~~
    c_loader < (file_ptr) sizeof core.old
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 #else
 ~~~~~
    c_loader < (file_ptr) sizeof core.new_dump
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 #endif
 ~~~~~~
    || c_loader >= statbuf.st_size
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    || c_loader >= c_stack))
    ^~~~~~~~~~~~~~~~~~~~~~~
rs6000-core.c:463:4: error: 'c_stack' may be used uninitialized in this function [-Werror=maybe-uninitialized]
rs6000-core.c:444:16: error: 'c_flag' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   if (!(c_flag & (FULL_CORE | CORE_TRUNC)))
        ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
rs6000-core.c: In function 'rs6000coff_core_file_matches_executable_p':
rs6000-core.c:727:36: error: 'c_loader' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   if (bfd_seek (core_bfd, c_loader + size, SEEK_SET) != 0)
                           ~~~~~~~~~^~~~~~
cc1: all warnings being treated as errors
Makefile:1688: recipe for target 'rs6000-core.lo' failed
gmake[2]: *** [rs6000-core.lo] Error 1
gmake[2]: Leaving directory '/home/code/src/binutils-gdb/bfd'
Makefile:1731: recipe for target 'all-recursive' failed
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory '/home/code/src/binutils-gdb/bfd'
Makefile:1201: recipe for target 'all' failed
gmake: *** [all] Error 2


[-- Attachment #3: bfd-aix-warnings.patch --]
[-- Type: text/x-patch, Size: 1412 bytes --]

From 1368829232b829d23b1d3bfc006118b3330a0a6a Mon Sep 17 00:00:00 2001
From: Sam Thursfield <sam.thursfield@codethink.co.uk>
Date: Wed, 1 Mar 2017 11:51:05 -0600
Subject: [PATCH] bfd: Fix initialized data warnings for rs6000 on 64-bit AIX
 >= 4.3

I got a load of compile warnings about initialized memory in
rs6000-core.c when compiling on an AIX 7.2 POWER machine.

The cause is the CORE_NEW macro. This macro should (according to
the comment) return 1 if a given CoreHdr structure contains data
in the new AIX 4.3+ format. On systems where AIX_CORE_DUMPX_CORE
and BFD64 are true the CoreHdr structure can only contain a new
style core dump so the macro always evaluates to 1. The compiler
doesn't know this and gives a warning. Still, since we know the
macro will always evaluate to 1 we can define it to 1 and fix the
warnings.

bfd/ChangeLog:
    * rs6000-core.c: Simplify CORE_NEW macro when AIX_CORE_DUMPX_CORE
    and BFD64 are true to avoid compile warning.
---
 bfd/rs6000-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bfd/rs6000-core.c b/bfd/rs6000-core.c
index 0e66cc3..e4a8cd0 100644
--- a/bfd/rs6000-core.c
+++ b/bfd/rs6000-core.c
@@ -137,7 +137,7 @@ typedef union
 # ifndef BFD64
 #  define CORE_NEW(c)        (!(c).old.c_entries)
 # else
-#  define CORE_NEW(c)   (!(c).new_dump.c_entries)
+#  define CORE_NEW(c)   1
 # endif
 #else
 # define CORE_NEW(c)	0
-- 
2.2.2

Re: [PATCH]: bfd: Fix uninitialized data warnings on AIX

[Nick Clifton]

Hi Sam,

> Attached is a patch which fixes them.

Thanks!  I have applied your patch.  Please let me know if you continue to have problems like this.

Cheers
  Nick