Rewrite __start and __stop symbol handling
authorAlan Modra <amodra@gmail.com>
Fri, 16 Jun 2017 10:11:41 +0000 (19:41 +0930)
committerAlan Modra <amodra@gmail.com>
Fri, 16 Jun 2017 14:08:28 +0000 (23:38 +0930)
commit7dba9362c172f1073487536eb137feb2da30b0ff
tree6dad1f8f6d06e52dd42e155c9ead55e5781af4a8
parentd68f19767dfbb33c1813563d5a4af0731a1855c5
Rewrite __start and __stop symbol handling

This arranges for __start and __stop symbols to be defined before
garbage collection, for all target formats.  That should allow the
COFF and PE --gc-sections to keep a singleton orphan input section,
a feature lost by 2017-06-13 commit cbd0eecf26.  The fancier ELF
treatment of keeping all input sections associated with a __start or
__stop symbol, from 2015-10-23 commit 1cce69b9dc, is retained.

.startof. and .sizeof. symbols are deliberately not defined before
garbage collection, so these won't affect garbage collection of
sections.

The patch also ensures __start, __stop, .startof. and .sizeof. symbols
are defined before target size_dynamic_sections is called, albeit
with a preliminary value, so that target code doesn't need to cope
with a symbol changing from undefined at size_dynamic_sections to
defined at relocate_section.

Also, a number of problems with the testcases have been fixed.

PR ld/20022
PR ld/21557
PR ld/21562
PR ld/21571
include/
* bfdlink.h (struct bfd_link_hash_entry): Delete undef.section.
bfd/
* targets.c (struct bfd_target): Add _bfd_define_start_stop.
(BFD_JUMP_TABLE_LINK): Likewise.
* elf-bfd.h (bfd_elf_define_start_stop): Declare.
* elflink.c (_bfd_elf_gc_mark_rsec): Update comment.
(bfd_elf_define_start_stop): New function.
* linker.c (bfd_generic_define_start_stop): New function.
* coff64-rs6000.c (rs6000_xcoff64_vec, rs6000_xcoff64_aix_vec): Init
new field.
* aout-adobe.c (aout_32_bfd_define_start_stop): Define.
* aout-target.h (MY_bfd_define_start_stop): Define.
* aout-tic30.c (MY_bfd_define_start_stop): Define.
* binary.c (binary_bfd_define_start_stop): Define.
* bout.c (b_out_bfd_define_start_stop): Define.
* coff-alpha.c (_bfd_ecoff_bfd_define_start_stop): Define.
* coff-mips.c (_bfd_ecoff_bfd_define_start_stop): Define.
* coff-rs6000.c (_bfd_xcoff_bfd_define_start_stop): Define.
* coffcode.h (coff_bfd_define_start_stop): Define.
* elfxx-target.h (bfd_elfNN_bfd_define_start_stop): Define.
* i386msdos.c (msdos_bfd_define_start_stop): Define.
* i386os9k.c (os9k_bfd_define_start_stop): Define.
* ieee.c (ieee_bfd_define_start_stop): Define.
* ihex.c (ihex_bfd_define_start_stop): Define.
* libbfd-in.h (_bfd_nolink_bfd_define_start_stop): Define.
* mach-o-target.c (bfd_mach_o_bfd_define_start_stop): Define.
* mmo.c (mmo_bfd_define_start_stop): Define.
* nlm-target.h (nlm_bfd_define_start_stop): Define.
* oasys.c (oasys_bfd_define_start_stop): Define.
* pef.c (bfd_pef_bfd_define_start_stop): Define.
* plugin.c (bfd_plugin_bfd_define_start_stop): Define.
* ppcboot.c (ppcboot_bfd_define_start_stop): Define.
* som.c (som_bfd_define_start_stop): Define.
* srec.c (srec_bfd_define_start_stop): Define.
* tekhex.c (tekhex_bfd_define_start_stop): Define.
* versados.c (versados_bfd_define_start_stop): Define.
* vms-alpha.c (vms_bfd_define_start_stop): Define.
(alpha_vms_bfd_define_start_stop): Define.
* xsym.c (bfd_sym_bfd_define_start_stop): Define.
* bfd-in2.h: Regenerate.
* libbfd.h: Regenerate.
ld/
* emultempl/elf32.em (gld${EMULATION_NAME}_after_open): Don't set
__start/__stop syms here.
* ldlang.c (lang_set_startof): Delete.
(start_stop_syms, start_stop_count, start_stop_alloc): New vars.
(lang_define_start_stop, lang_init_start_stop, foreach_start_stop,
undef_start_stop, lang_undef_start_stop, lang_init_startof_sizeof,
set_start_stop, lang_finalize_start_stop): New functions.
(lang_process): Call _start_stop functions.
* testsuite/ld-elf/pr21562a.d: Use xfail rather than notarget.
Correct typos and list of xfail targets.
* testsuite/ld-elf/pr21562b.d: Likewise.
* testsuite/ld-elf/pr21562c.d: Likewise.
* testsuite/ld-elf/pr21562d.d: Likewise.
* testsuite/ld-elf/pr21562e.d: Likewise.
* testsuite/ld-elf/pr21562f.d: Likewise.
* testsuite/ld-elf/pr21562g.d: Likewise.
* testsuite/ld-elf/pr21562h.d: Likewise.
* testsuite/ld-elf/pr21562i.d: Likewise.
* testsuite/ld-elf/pr21562j.d: Likewise.
* testsuite/ld-elf/pr21562k.d: Likewise.
* testsuite/ld-elf/pr21562l.d: Likewise.
* testsuite/ld-elf/pr21562m.d: Likewise.
* testsuite/ld-elf/pr21562n.d: Likewise.
* testsuite/ld-elf/sizeofa.d: Likewise.  Adjust to pass for generic ELF.
* testsuite/ld-elf/sizeofb.d: Likewise.
* testsuite/ld-elf/startofa.d: Likewise.
* testsuite/ld-elf/startofb.d: Likewise.
59 files changed:
bfd/ChangeLog
bfd/aout-adobe.c
bfd/aout-target.h
bfd/aout-tic30.c
bfd/bfd-in2.h
bfd/binary.c
bfd/bout.c
bfd/coff-alpha.c
bfd/coff-mips.c
bfd/coff-rs6000.c
bfd/coff64-rs6000.c
bfd/coffcode.h
bfd/elf-bfd.h
bfd/elflink.c
bfd/elfxx-target.h
bfd/i386msdos.c
bfd/i386os9k.c
bfd/ieee.c
bfd/ihex.c
bfd/libbfd-in.h
bfd/libbfd.h
bfd/linker.c
bfd/mach-o-target.c
bfd/mmo.c
bfd/nlm-target.h
bfd/oasys.c
bfd/pef.c
bfd/plugin.c
bfd/ppcboot.c
bfd/som.c
bfd/srec.c
bfd/targets.c
bfd/tekhex.c
bfd/versados.c
bfd/vms-alpha.c
bfd/xsym.c
include/ChangeLog
include/bfdlink.h
ld/ChangeLog
ld/emultempl/elf32.em
ld/ldlang.c
ld/testsuite/ld-elf/pr21562a.d
ld/testsuite/ld-elf/pr21562b.d
ld/testsuite/ld-elf/pr21562c.d
ld/testsuite/ld-elf/pr21562d.d
ld/testsuite/ld-elf/pr21562e.d
ld/testsuite/ld-elf/pr21562f.d
ld/testsuite/ld-elf/pr21562g.d
ld/testsuite/ld-elf/pr21562h.d
ld/testsuite/ld-elf/pr21562i.d
ld/testsuite/ld-elf/pr21562j.d
ld/testsuite/ld-elf/pr21562k.d
ld/testsuite/ld-elf/pr21562l.d
ld/testsuite/ld-elf/pr21562m.d
ld/testsuite/ld-elf/pr21562n.d
ld/testsuite/ld-elf/sizeofa.d
ld/testsuite/ld-elf/sizeofb.d
ld/testsuite/ld-elf/startofa.d
ld/testsuite/ld-elf/startofb.d