x86: Remove the unused _GLOBAL_OFFSET_TABLE_
authorH.J. Lu <hjl.tools@gmail.com>
Mon, 5 Feb 2018 16:38:16 +0000 (08:38 -0800)
committerH.J. Lu <hjl.tools@gmail.com>
Mon, 5 Feb 2018 16:38:16 +0000 (08:38 -0800)
commitcd04836359da82ae1dc67e5a05565536f4427b51
treefc72f6593a58e26174caadbfe9515204901fb318
parentb8df6ca79e69678a07d3216b9b2b552fce27cda8
x86: Remove the unused _GLOBAL_OFFSET_TABLE_

Since _GLOBAL_OFFSET_TABLE_ may be referenced implicitly on x86,
checking ref_regular_nonweak leaves the unused _GLOBAL_OFFSET_TABLE_
in output.  This patch checks explicit GOT references instead.

ld-i386/discarded1.s and ld-x86-64/discarded1.s are updated to avoid
linker optimization which removes GOT references.

bfd/

PR ld/22782
* elf32-i386.c (elf_i386_check_relocs): Set got_referenced if
_GLOBAL_OFFSET_TABLE_ is referenced or GOT is needed to resolve
undefined weak symbol to 0.
* elf64-x86-64.c (elf_x86_64_check_relocs): Set got_referenced
if _GLOBAL_OFFSET_TABLE_ is referenced.
* elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Check
got_referenced instead of ref_regular_nonweak.  Remove the
unused _GLOBAL_OFFSET_TABLE_ from symbol table.
* elfxx-x86.h (elf_x86_link_hash_table): Add got_referenced.

ld/

PR ld/22782
* testsuite/ld-i386/discarded1.s: Replace mov with div.
* testsuite/ld-x86-64/discarded1.s: Likewise.
* testsuite/ld-i386/i386.exp: Run pr22782.
* testsuite/ld-i386/load1-nacl.d: Updated for removing
_GLOBAL_OFFSET_TABLE_ from output.
* testsuite/ld-i386/load1.d: Likewise.
* testsuite/ld-x86-64/load1a-nacl.d: Likewise.
* testsuite/ld-x86-64/load1a.d: Likewise.
* testsuite/ld-x86-64/load1b-nacl.d: Likewise.
* testsuite/ld-x86-64/load1b.d: Likewise.
* testsuite/ld-i386/pr22782.d: New file.
* testsuite/ld-i386/pr22782.s: Likewise.
* testsuite/ld-x86-64/pr22782.s: Likewise.
* testsuite/ld-x86-64/pr22782a.d: Likewise.
* testsuite/ld-x86-64/pr22782b.d: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr22782a and pr22782b.
21 files changed:
bfd/ChangeLog
bfd/elf32-i386.c
bfd/elf64-x86-64.c
bfd/elfxx-x86.c
bfd/elfxx-x86.h
ld/ChangeLog
ld/testsuite/ld-i386/discarded1.s
ld/testsuite/ld-i386/i386.exp
ld/testsuite/ld-i386/load1-nacl.d
ld/testsuite/ld-i386/load1.d
ld/testsuite/ld-i386/pr22782.d [new file with mode: 0644]
ld/testsuite/ld-i386/pr22782.s [new file with mode: 0644]
ld/testsuite/ld-x86-64/discarded1.s
ld/testsuite/ld-x86-64/load1a-nacl.d
ld/testsuite/ld-x86-64/load1a.d
ld/testsuite/ld-x86-64/load1b-nacl.d
ld/testsuite/ld-x86-64/load1b.d
ld/testsuite/ld-x86-64/pr22782.s [new file with mode: 0644]
ld/testsuite/ld-x86-64/pr22782a.d [new file with mode: 0644]
ld/testsuite/ld-x86-64/pr22782b.d [new file with mode: 0644]
ld/testsuite/ld-x86-64/x86-64.exp