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From: "jal2 at gmx dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/60158] New: powerpc: usage of the .data.rel.ro.local section
Date: Wed, 12 Feb 2014 10:59:00 -0000
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X-Bugzilla-Component: c
X-Bugzilla-Version: 4.8.2
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60158

            Bug ID: 60158
           Summary: powerpc: usage of the .data.rel.ro.local section
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jal2 at gmx dot de

This bug may concern the gcc documentation on section usage only.

Crosscompiling "Das U-Boot" with gcc 4.8.2 for powerpc with
-fpic -mrelocatable, some addresses are put into a section .data.rel.ro.local,
e.g. the address of "qwerty" from

printf("%p\n", "qwerty");

There is no corresponding entry in the .fixup section.
As "Das U-Boot" relocates itself to RAM using .got2/.got and .fixup sections
only, how shall the section .data.rel.ro.local be handled?

Currently it contains addresses only, but this may depend on the source code.
I put .data.rel.ro.local into the GOT which solved my problem, but I'm not sure
if this is the intention of the gcc developers.

I've tried gcc 4.7.3 which put the address of "qwerty" into the GOT directly,
i.e. there was no .data.rel.ro.local section and the string address was
accessed with one redirection less.

details:
- gcc version: powerpc-softfloat-linux-gnuspe-gcc (Gentoo 4.8.2 p1.3r1,
pie-0.5.8r1) 4.8.2
- gcc command line (some -I removed):
  -g -gdwarf-2  -Os   -fpic -mrelocatable \
  -meabi \
  -D__KERNEL__ -DCONFIG_SYS_TEXT_BASE=0xef770000 \
  -fno-builtin  -ffreestanding \
  -isystem /usr/lib/gcc/powerpc-softfloat-linux-gnuspe/4.8.1/include \
  -nostdinc -pipe  -DCONFIG_PPC -D__powerpc__ -ffixed-r2 -Wa,-me500 \
  -msoft-float -mno-string -mspe=yes -mno-spe -Wall -Wstrict-prototypes \
  -fno-stack-protector -Wno-format-nonliteral -Wno-format-security \
  -fstack-usage"