5c3261b0e8
For all ELF targers, call check_relocs after opening all inputs and garbage collection. Since the symbol resolution is known, check_relocs can be simplified. Also garbage collection doesn't need to undo what check_relocs has done for symbols which have been garbage collected. Since ELF targets never see the removed sections, gc_sweep_hook can be removed from elf_backend_data and we can avoid GOT/PLT with garbage collection now. Set link_info.check_relocs_after_open_input to TRUE for all linker targets which use ELF linker and update garbage collection tests to remove unused GOT section. ldemul_after_check_relocs is added for powerpc to support --secure-plt, --bss-plt and --sdata-got. Tested natively without regressions on i686, x86-64 and x32. Tested cross binutils on x86-64 without regressions for aarch64-linux, alpha-linux, arm-linux, bfin-elf, cr16-elf, cris-elf, crx-elf, frv-linux, hppa64-linux, hppa-linux, ia64-linux, lm32-elf, m32r-elf, m68k-linux, mcore-elf, metag-elf, microblaze-linux, mips-linux, mmix, mn10300-elf, nds32le-linux, nios2-linux, or1k-elf, powerpc64-linux, powerpc-linux, riscv32-linux, riscv64-linux, s390-linux, s390x-linux, score-elf, sh3-linux, sparc64-linux, sparc-linux, tic6x-elf, tilegx-linux, tilepro-linux, vax-linux, x86_64-mingw32 and xtensa-linux. bfd/ * elf-bfd.h (elf_backend_data): Remove gc_sweep_hook. * elf32-arm.c (elf32_arm_gc_sweep_hook): Removed. (elf_backend_gc_sweep_hook): Likewise. * elf32-bfin.c (bfin_gc_sweep_hook): Likewise. (bfinfdpic_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-cr16.c (elf32_cr16_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-cris.c (cris_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-hppa.c (elf32_hppa_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-lm32.c (lm32_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-m32r.c (m32r_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-m68k.c (elf_m68k_got_entry): Remove elf_m68k_gc_sweep_hook from comments. (elf_m68k_remove_got_entry_type): Removed. (elf_m68k_find_got_entry_ptr): Likewise. (elf_m68k_remove_got_entry): Likewise. (elf_m68k_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-mcore.c (mcore_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-metag.c (elf_metag_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-microblaze.c (elf_backend_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-mips.c (elf_backend_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-nds32.c (nds32_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-nios2.c (nios2_elf32_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-or1k.c (or1k_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-ppc.c (ppc_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-s390.c (elf_s390_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-sparc.c (elf_backend_gc_sweep_hook): Likewise. * elf32-tic6x.c (elf32_tic6x_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-tilegx.c (elf_backend_gc_sweep_hook): Likewise. * elf32-tilepro.c (tilepro_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-vax.c (elf_vax_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf32-xtensa.c (elf_xtensa_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf64-alpha.c (elf64_alpha_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf64-mips.c (elf_backend_gc_sweep_hook): Likewise. * elf64-mmix.c (mmix_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf64-ppc.c (elf_backend_gc_sweep_hook): Likewise. (ppc64_elf_gc_sweep_hook): Likewise. * elf64-s390.c (elf_s390_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elf64-sparc.c (elf_backend_gc_sweep_hook): Likewise. * elf64-tilegx.c (elf_backend_gc_sweep_hook): Likewise. * elflink.c (elf_link_add_object_symbols): Don't call _bfd_elf_link_check_relocs here. (gc_sweep_hook_fn): Removed. (elf_gc_sweep): Remove gc_sweep_hook. * elfnn-aarch64.c (elfNN_aarch64_gc_sweep_hook): Removed. (elf_backend_gc_sweep_hook): Likewise. * elfnn-riscv.c (riscv_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elfxx-mips.c (_bfd_mips_elf_gc_sweep_hook): Likewise. * elfxx-mips.h (_bfd_mips_elf_gc_sweep_hook): Likewise. (elf_backend_gc_sweep_hook): Likewise. * elfxx-sparc.c (_bfd_sparc_elf_gc_sweep_hook): Likewise. * elfxx-sparc.h (_bfd_sparc_elf_gc_sweep_hook): Likewise. * elfxx-target.h (elf_backend_gc_sweep_hook): Likewise. (elfNN_bed): Remove elf_backend_gc_sweep_hook. * elfxx-tilegx.c (tilegx_elf_gc_sweep_hook): Removed. * elfxx-tilegx.h (tilegx_elf_gc_sweep_hook): Likewise. ld/ * emulparams/elf32_x86_64.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Removed. * emulparams/elf_i386_be.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/elf_i386_chaos.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/elf_i386_ldso.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/elf_i386_vxworks.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/elf_iamcu.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/elf_k1om.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/elf_l1om.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/elf_x86_64.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/i386lynx.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/i386moss.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/i386nto.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/i386nw.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/shelf.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/shelf32.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/shelf_nto.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/shelf_vxworks.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/shlelf32_linux.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/shlelf_linux.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emulparams/shlelf_nto.sh (CHECK_RELOCS_AFTER_OPEN_INPUT): Likewise. * emultempl/aarch64elf.em (gld${EMULATION_NAME}_before_parse): Set link_info.check_relocs_after_open_input to TRUE. * emultempl/armelf.em (gld${EMULATION_NAME}_before_parse): Likewise. * emultempl/scoreelf.em (gld${EMULATION_NAME}_before_parse): Likewise. * emultempl/aix.em (ld_${EMULATION_NAME}_emulation): Add after_parse_default. * emultempl/armcoff.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/beos.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/generic.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/gld960.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/gld960c.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/lnk960.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/m68kcoff.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/msp430.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/pe.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/pep.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/sunos.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/ticoff.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/vanilla.em (ld_${EMULATION_NAME}_emulation): Likewise. * emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Always set link_info.check_relocs_after_open_input to TRUE. (ld_${EMULATION_NAME}_emulation): Add $LDEMUL_AFTER_CHECK_RELOCS. * emultempl/linux.em (gld${EMULATION_NAME}_before_parse): Set link_info.check_relocs_after_open_input to TRUE. (ld_${EMULATION_NAME}_emulation): Add after_check_relocs_default. * emultempl/mmix-elfnmmo.em (mmix_before_parse): New function. (LDEMUL_BEFORE_PARSE): New. * emultempl/mmixelf.em (elfmmix_before_parse): Replace gld${EMULATION_NAME}_before_parse with mmix_before_parse. * emultempl/ppc32elf.em (ppc_after_open): Renamed to ... (ppc_after_check_relocs): This. Call after_check_relocs_default instead of gld${EMULATION_NAME}_after_open. (LDEMUL_AFTER_OPEN): Removed. (LDEMUL_AFTER_CHECK_RELOCS): New. * ldemul.c (ldemul_after_check_relocs): New. (after_check_relocs_default): Likewise. * ldemul.h (ldemul_after_check_relocs): Likewise. (after_check_relocs_default): Likewise. (ld_emulation_xfer_struct): Add after_check_relocs. * ldlang.c (lang_process): Call ldemul_after_check_relocs after lang_check_relocs. * testsuite/ld-aarch64/gc-got-relocs.d: Don't expect GOT section. * testsuite/ld-aarch64/gc-tls-relocs.d: Likewise. * testsuite/ld-cris/tls-gc-68.d: Likewise. * testsuite/ld-cris/tls-gc-69.d: Likewise. * testsuite/ld-cris/tls-gc-70.d: Likewise. * testsuite/ld-cris/tls-gc-75.d: Likewise. * testsuite/ld-cris/tls-gc-79.d: Likewise. * testsuite/ld-mmix/bpo-10.d: Don't expect .MMIX.reg_contents section. |
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.. | ||
emulparams | ||
emultempl | ||
po | ||
scripttempl | ||
testsuite | ||
.gitignore | ||
aclocal.m4 | ||
ChangeLog | ||
ChangeLog-0001 | ||
ChangeLog-0203 | ||
ChangeLog-2004 | ||
ChangeLog-2005 | ||
ChangeLog-2006 | ||
ChangeLog-2007 | ||
ChangeLog-2008 | ||
ChangeLog-2009 | ||
ChangeLog-2010 | ||
ChangeLog-2011 | ||
ChangeLog-2012 | ||
ChangeLog-2013 | ||
ChangeLog-2014 | ||
ChangeLog-2015 | ||
ChangeLog-2016 | ||
ChangeLog-9197 | ||
ChangeLog-9899 | ||
config.in | ||
configure | ||
configure.ac | ||
configure.host | ||
configure.tgt | ||
deffile.h | ||
deffilep.y | ||
dep-in.sed | ||
elf-hints-local.h | ||
fdl.texi | ||
gen-doc.texi | ||
genscrba.sh | ||
genscripts.sh | ||
h8-doc.texi | ||
ld.h | ||
ld.texinfo | ||
ldbuildid.c | ||
ldbuildid.h | ||
ldcref.c | ||
ldctor.c | ||
ldctor.h | ||
ldemul.c | ||
ldemul.h | ||
ldexp.c | ||
ldexp.h | ||
ldfile.c | ||
ldfile.h | ||
ldgram.y | ||
ldint.texinfo | ||
ldlang.c | ||
ldlang.h | ||
ldlex-wrapper.c | ||
ldlex.h | ||
ldlex.l | ||
ldmain.c | ||
ldmain.h | ||
ldmisc.c | ||
ldmisc.h | ||
ldver.c | ||
ldver.h | ||
ldwrite.c | ||
ldwrite.h | ||
lexsup.c | ||
MAINTAINERS | ||
Makefile.am | ||
Makefile.in | ||
mri.c | ||
mri.h | ||
NEWS | ||
pe-dll.c | ||
pe-dll.h | ||
pep-dll.c | ||
pep-dll.h | ||
plugin.c | ||
plugin.h | ||
README | ||
stamp-h.in | ||
sysdep.h | ||
testplug2.c | ||
testplug3.c | ||
testplug4.c | ||
testplug.c | ||
TODO |
README for LD
This is the GNU linker. It is distributed with other "binary
utilities" which should be in ../binutils. See ../binutils/README for
more general notes, including where to send bug reports.
There are many features of the linker:
* The linker uses a Binary File Descriptor library (../bfd)
that it uses to read and write object files. This helps
insulate the linker itself from the format of object files.
* The linker supports a number of different object file
formats. It can even handle multiple formats at once:
Read two input formats and write a third.
* The linker can be configured for cross-linking.
* The linker supports a control language.
* There is a user manual (ld.texinfo), as well as the
beginnings of an internals manual (ldint.texinfo).
Installation
============
See ../binutils/README.
If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile
or using the --with-lib-path configure switch.
To build just the linker, make the target all-ld from the top level
directory (one directory above this one).
Porting to a new target
=======================
See the ldint.texinfo manual.
Reporting bugs etc
===========================
See ../binutils/README.
Known problems
==============
The Solaris linker normally exports all dynamic symbols from an
executable. The GNU linker does not do this by default. This is
because the GNU linker tries to present the same interface for all
similar targets (in this case, all native ELF targets). This does not
matter for normal programs, but it can make a difference for programs
which try to dlopen an executable, such as PERL or Tcl. You can make
the GNU linker export all dynamic symbols with the -E or
--export-dynamic command line option.
HP/UX 9.01 has a shell bug that causes the linker scripts to be
generated incorrectly. The symptom of this appears to be "fatal error
- scanner input buffer overflow" error messages. There are various
workarounds to this:
* Build and install bash, and build with "make SHELL=bash".
* Update to a version of HP/UX with a working shell (e.g., 9.05).
* Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
genscripts.sh with "sh ${srcdir}..." (no parens) and make sure the
emulparams script used exports any shell variables it sets.
Copyright (C) 2012-2017 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.