a8c4d40b57
Clang's integrated assembler supports multiple section with the same name: .section .text,"ax",@progbits,unique,1 nop .section .text,"ax",@progbits,unique,2 nop "unique,N" assigns the number, N, as the section ID, to a section. The valid values of the section ID are between 0 and 4294967295. It can be used to distinguish different sections with the same section name. This is useful with -fno-unique-section-names -ffunction-sections. -ffunction-sections by default generates .text.foo, .text.bar, etc. Using the same string can save lots of space in .strtab. This patch adds section_id to bfd_section and reuses the linker internal bit in BFD section flags, SEC_LINKER_CREATED, for assmebler internal use to mark valid section_id. It also updates objdump to compare section pointers if 2 sections comes from the same file since 2 different sections can have the same section name. bfd/ PR gas/25380 * bfd-in2.h: Regenerated. * ecoff.c (bfd_debug_section): Add section_id. * section.c (bfd_section): Add section_id. (SEC_ASSEMBLER_SECTION_ID): New. (BFD_FAKE_SECTION): Add section_id. binutils/ PR gas/25380 * objdump.c (sym_ok): Return FALSE if 2 sections are in the same file with different section pointers. gas/ PR gas/25380 * config/obj-elf.c (section_match): Removed. (get_section): Also match SEC_ASSEMBLER_SECTION_ID and section_id. (obj_elf_change_section): Replace info and group_name arguments with match_p. Also update the section ID and flags from match_p. (obj_elf_section): Handle "unique,N". Update call to obj_elf_change_section. * config/obj-elf.h (elf_section_match): New. (obj_elf_change_section): Updated. * config/tc-arm.c (start_unwind_section): Update call to obj_elf_change_section. * config/tc-ia64.c (obj_elf_vms_common): Likewise. * config/tc-microblaze.c (microblaze_s_data): Likewise. (microblaze_s_sdata): Likewise. (microblaze_s_rdata): Likewise. (microblaze_s_bss): Likewise. * config/tc-mips.c (s_change_section): Likewise. * config/tc-msp430.c (msp430_profiler): Likewise. * config/tc-rx.c (parse_rx_section): Likewise. * config/tc-tic6x.c (tic6x_start_unwind_section): Likewise. * doc/as.texi: Document "unique,N" in .section directive. * testsuite/gas/elf/elf.exp: Run "unique,N" tests. * testsuite/gas/elf/section15.d: New file. * testsuite/gas/elf/section15.s: Likewise. * testsuite/gas/elf/section16.s: Likewise. * testsuite/gas/elf/section16a.d: Likewise. * testsuite/gas/elf/section16b.d: Likewise. * testsuite/gas/elf/section17.d: Likewise. * testsuite/gas/elf/section17.l: Likewise. * testsuite/gas/elf/section17.s: Likewise. * testsuite/gas/i386/unique.d: Likewise. * testsuite/gas/i386/unique.s: Likewise. * testsuite/gas/i386/x86-64-unique.d: Likewise. * testsuite/gas/i386/i386.exp: Run unique and x86-64-unique. ld/ PR gas/25380 * testsuite/ld-i386/pr22001-1c.S: Use "unique,N" in .section directives. * testsuite/ld-i386/tls-gd1.S: Likewise. * testsuite/ld-x86-64/pr21481b.S: Likewise. |
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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-2017 | ||
ChangeLog-2018 | ||
ChangeLog-2019 | ||
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.texi | ||
ldbuildid.c | ||
ldbuildid.h | ||
ldcref.c | ||
ldctor.c | ||
ldctor.h | ||
ldelf.c | ||
ldelf.h | ||
ldelfgen.c | ||
ldelfgen.h | ||
ldemul.c | ||
ldemul.h | ||
ldexp.c | ||
ldexp.h | ||
ldfile.c | ||
ldfile.h | ||
ldgram.y | ||
ldint.texi | ||
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.texi), as well as the
beginnings of an internals manual (ldint.texi).
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.texi 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) 2012-2020 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.