binutils-gdb/ld
Maciej W. Rozycki 97c79e2174 PR ld/26288: Allow the use of `--just-symbols' with ET_EXEC input
Fix a regression from commit a87e1817a4 ("Have the linker fail if any
attempt to link in an executable is made.") and do not reject ET_EXEC
input supplied with the `--just-symbols' option.  Such use is legitimate
as the file requested is not actually linked and only the symbols are
extracted. Furthermore it is often the most useful application, as
already observed in our documentation for the option, where it allows
"to refer symbolically to absolute locations of memory defined in other
programs."

Provide a set of tests for the use of ET_EXEC with `--just-symbols'.
These are excluded however for SH/PE targets because they complain if a
section's VMA is 0:

ld: zero vma section reloc detected: `.text' #0 f=32795
ld: zero vma section reloc detected: `.data' #1 f=291

and for x86_64/PE targets because they seem to hardwire the VMA:

 100000000 12000000 01000000 00000000 00000000  ................

	ld/
	PR ld/26288
	* ldelf.c (ldelf_after_open): Do not reject ET_EXEC input
	supplied with `--just-symbols'.
	* testsuite/ld-misc/just-symbols.exp: New test script.
	* testsuite/ld-misc/just-symbols-1.dd: New test dump.
	* testsuite/ld-misc/just-symbols.ld: New test linker script.
	* testsuite/ld-misc/just-symbols-0.s: New test source.
	* testsuite/ld-misc/just-symbols-1.s: New test source.
2020-07-23 20:11:29 +01:00
..
emulparams ld: optionally emit _etext last, before .data 2020-07-19 06:08:07 +02:00
emultempl Power10 stub selection 2020-07-19 12:27:47 +09:30
po Remove powerpc PE support 2020-07-09 22:58:16 +09:30
scripttempl ld: optionally emit _etext last, before .data 2020-07-19 06:08:07 +02:00
testsuite PR ld/26288: Allow the use of `--just-symbols' with ET_EXEC input 2020-07-23 20:11:29 +01:00
.gitignore
aclocal.m4 binutils, ld: work with --disable-libctf 2020-06-26 15:56:39 +01:00
ChangeLog PR ld/26288: Allow the use of `--just-symbols' with ET_EXEC input 2020-07-23 20:11:29 +01:00
ChangeLog-0001
ChangeLog-0203
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ChangeLog-2019
ChangeLog-9197
ChangeLog-9899
config.in binutils, ld: work with --disable-libctf 2020-06-26 15:56:39 +01:00
configure ld, testsuite: only run CTF tests when ld and GCC support CTF 2020-07-22 18:05:32 +01:00
configure.ac ld, testsuite: only run CTF tests when ld and GCC support CTF 2020-07-22 18:05:32 +01:00
configure.host
configure.tgt Remove powerpc PE support 2020-07-09 22:58:16 +09:30
deffile.h
deffilep.y Replace "if (x) free (x)" with "free (x)", ld 2020-05-21 10:45:33 +09:30
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi
genscrba.sh
genscripts.sh
h8-doc.texi
ld.h ld: new options --ctf-variables and --ctf-share-types 2020-07-22 18:03:57 +01:00
ld.texi ld: new options --ctf-variables and --ctf-share-types 2020-07-22 18:03:57 +01:00
ldbuildid.c
ldbuildid.h
ldcref.c
ldctor.c
ldctor.h
ldelf.c PR ld/26288: Allow the use of `--just-symbols' with ET_EXEC input 2020-07-23 20:11:29 +01:00
ldelf.h
ldelfgen.c binutils, ld: work with --disable-libctf 2020-06-26 15:56:39 +01:00
ldelfgen.h
ldemul.c Show AIX gc'd symbol address adjustments in map file 2020-05-18 22:41:32 +09:30
ldemul.h Show AIX gc'd symbol address adjustments in map file 2020-05-18 22:41:32 +09:30
ldexp.c ld: Set non_ir_ref_regular on source for assignment 2020-06-24 03:56:16 -07:00
ldexp.h
ldfile.c PR 22843: ld, gold: Add --dependency-file option. 2020-06-23 12:01:24 -07:00
ldfile.h
ldgram.y ld: Add --export-dynamic-symbol and --export-dynamic-symbol-list 2020-06-03 06:37:39 -07:00
ldint.texi
ldlang.c ld: do not produce one empty output .ctf section for every input .ctf 2020-07-22 18:05:32 +01:00
ldlang.h Do without ld ENABLE_PLUGINS 2020-06-21 22:16:10 +09:30
ldlex-wrapper.c
ldlex.h ld: new options --ctf-variables and --ctf-share-types 2020-07-22 18:03:57 +01:00
ldlex.l
ldmain.c PR 22843: ld, gold: Add --dependency-file option. 2020-06-23 12:01:24 -07:00
ldmain.h PR 22843: ld, gold: Add --dependency-file option. 2020-06-23 12:01:24 -07:00
ldmisc.c Replace "if (x) free (x)" with "free (x)", ld 2020-05-21 10:45:33 +09:30
ldmisc.h
ldver.c
ldver.h
ldwrite.c
ldwrite.h
lexsup.c ld: new options --ctf-variables and --ctf-share-types 2020-07-22 18:03:57 +01:00
MAINTAINERS
Makefile.am ld, testsuite: only run CTF tests when ld and GCC support CTF 2020-07-22 18:05:32 +01:00
Makefile.in ld, testsuite: only run CTF tests when ld and GCC support CTF 2020-07-22 18:05:32 +01:00
mri.c
mri.h
NEWS ld: new options --ctf-variables and --ctf-share-types 2020-07-22 18:03:57 +01:00
pe-dll.c PR 22843: ld, gold: Add --dependency-file option. 2020-06-23 12:01:24 -07:00
pe-dll.h
pep-dll.c
pep-dll.h
plugin.c ld: Properly override the IR definition 2020-07-22 03:49:17 -07:00
plugin.h
README
stamp-h.in
sysdep.h
testplug2.c Do without ld ENABLE_PLUGINS 2020-06-21 22:16:10 +09:30
testplug3.c Do without ld ENABLE_PLUGINS 2020-06-21 22:16:10 +09:30
testplug4.c Do without ld ENABLE_PLUGINS 2020-06-21 22:16:10 +09:30
testplug.c Do without ld ENABLE_PLUGINS 2020-06-21 22:16:10 +09:30
TODO

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		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.

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