binutils-gdb/ld
Eric Botcazou 317ff0084b Speed up direct linking with DLLs on Windows (1/2).
This patch deals with the auto-import feature.  There are 2 versions
of this feature: the original one, which was piggybacked on the OS
loader with an optional help from the runtime (--enable-auto-import
--enable-runtime-pseudo-reloc-v1) and is still the one mostly
documented in the sources and manual; the enhanced one by Kai Tietz,
which is entirely piggybacked on the runtime (--enable-auto-import
--enable-runtime-pseudo-reloc-v2) and is the default for Mingw and
Cygwin nowadays.

The implementation is inefficient because of pe[p]_find_data_imports:
for every undefined symbol, the function walks the entire set of
relocations for all the input files and does a direct name comparison
for each of them.

This is easily fixable by using a hash-based map for v1 and a simple
hash table for v2.  This patch leaves v1 alone and only changes v2.
It also factors out pe[p]_find_data_imports into a common function,
removes old cruft left and right, and attempts to better separate
the implementations of v1 and v2 in the code.

ld/
	* emultempl/pe.em (U_SIZE): Delete.
	(pe_data_import_dll): Likewise.
	(make_import_fixup): Return void, take 4th parameter and pass it down
	in call to pe_create_import_fixup.
	(pe_find_data_imports): Move to...
	(gld_${EMULATION_NAME}_after_open): Run the stdcall fixup pass after
	the auto-import pass and add a guard before running the latter.
	* emultempl/pep.em (U_SIZE): Delete.
	(pep_data_import_dll): Likewise.
	(make_import_fixup): Return void, take 4th parameter and pass it down
	in call to pe_create_import_fixup.
	(pep_find_data_imports): Move to...
	(gld_${EMULATION_NAME}_after_open): Run the stdcall fixup pass after
	the auto-import pass and add a guard before running the latter.
	* pe-dll.c (runtime_pseudp_reloc_v2_init): Change type to bfd_boolean.
	(pe_walk_relocs_of_symbol): Rename into...
	(pe_walk_relocs): ...this.  Add 2 more parameters,4th parameter to the
	callback prototype and pass 4th parameter in calls to the callback.
	If the import hash table is present, invoke the callback on the reloc
	if the symbol name is in the table.
	(pe_find_data_imports): ...here.  Take 2 parameters.  Build an import
	hash table for the pseudo-relocation support version 2.  When it is
	built, walk the relocations only once at the end; when it is not, do
	not build a fixup when the symbol isn't part of an import table.
	Issue the associated warning only after a first fixup is built.
	(tmp_seq2): Delete.
	(make_singleton_name_imp): Likewise.
	(make_import_fixup_mark): Return const char * and a stable string.
	(make_import_fixup_entry): Do not deal with the pseudo-relocation
	support version 2.
	(make_runtime_pseudo_reloc): Factor out code and fix formatting.
	(pe_create_import_fixup): Add 5th parameter.  Clearly separate the
	pseudo-relocation support version 2 from the rest.  Fix formatting.
	* pe-dll.h (pe_walk_relocs_of_symbol): Delete.
	(pe_find_data_imports): Declare.
	(pe_create_import_fixup): Add 5th parameter.
	* pep-dll.c (pe_data_import_dll): Delete.
	(pe_find_data_imports): Define.
	(pe_walk_relocs_of_symbol): Delete.
	* pep-dll.h (pep_walk_relocs_of_symbol): Delete.
	(pep_find_data_imports): Declare.
	(pep_create_import_fixup): Add 5th parameter.
	* ld.texinfo (--enable-auto-import): Adjust to new implementation.
2018-04-04 12:07:50 +02:00
..
emulparams xtensa: ld: support -z relro 2018-03-07 13:05:12 -08:00
emultempl Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
po Update Spanish translations for ld/ opcodes/ and gold/ sub-directories 2018-04-04 09:00:18 +01:00
scripttempl
testsuite MIPS/LD/testsuite: Correct LD emulations for `mips*-*-kfreebsd*-gnu' 2018-04-03 09:18:06 +01:00
.gitignore bfd/binutils/gas/gprof/ld/libiberty/opcodes: add .gitignore 2010-12-09 09:03:18 +00:00
aclocal.m4 Regenerate Makefile.in/aclocal.m4 automake 1.11.6 2016-04-15 16:20:55 -07:00
ChangeLog Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
ChangeLog-0001 Add copyright notices 2012-12-10 12:48:03 +00:00
ChangeLog-0203 Add copyright notices 2012-12-10 12:48:03 +00:00
ChangeLog-2004 Add copyright notices 2012-12-10 12:48:03 +00:00
ChangeLog-2005 Add copyright notices 2012-12-10 12:48:03 +00:00
ChangeLog-2006 Add copyright notices 2012-12-10 12:48:03 +00:00
ChangeLog-2007 Add copyright notices 2012-12-10 12:48:03 +00:00
ChangeLog-2008
ChangeLog-2009
ChangeLog-2010 Add copyright notices 2012-12-10 12:48:03 +00:00
ChangeLog-2011 Add copyright notices 2012-12-10 12:48:03 +00:00
ChangeLog-2012 Rotate binutils ChangeLog for 2013 2013-01-02 17:06:32 +00:00
ChangeLog-2013
ChangeLog-2014
ChangeLog-2015
ChangeLog-2016
ChangeLog-2017
ChangeLog-9197 Remove trailing spaces in ld 2015-08-12 04:46:43 -07:00
ChangeLog-9899 Add copyright notices 2012-12-10 12:48:03 +00:00
config.in ld: Add --enable-separate-code 2018-02-27 11:34:29 -08:00
configure Add missing translations to ALL_LINGUAS 2018-03-01 09:17:02 +10:30
configure.ac Add missing translations to ALL_LINGUAS 2018-03-01 09:17:02 +10:30
configure.host Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
configure.tgt ld: Add --enable-separate-code 2018-02-27 11:34:29 -08:00
deffile.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
deffilep.y Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
dep-in.sed * dep-in.sed: Don't use \n in replacement part of s command. 2009-06-04 06:57:56 +00:00
elf-hints-local.h
fdl.texi
gen-doc.texi
genscrba.sh
genscripts.sh
h8-doc.texi Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ld.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ld.texinfo Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
ldbuildid.c
ldbuildid.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ldcref.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldctor.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldctor.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ldemul.c Use %pI, %pR, %pS, %pT in place of %I, %R, %S and %T. 2018-02-19 23:55:53 +10:30
ldemul.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ldexp.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldexp.h ld: Remove unused expression state 2018-01-11 17:35:35 +00:00
ldfile.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldfile.h
ldgram.y ld error/warning messages 2018-02-26 10:51:12 +10:30
ldint.texinfo Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ldlang.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldlang.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ldlex-wrapper.c
ldlex.h LD: Remove a stale `ldlex_command' prototype 2018-02-14 09:15:43 +00:00
ldlex.l Use %pI, %pR, %pS, %pT in place of %I, %R, %S and %T. 2018-02-19 23:55:53 +10:30
ldmain.c Remove any trailing directory separator from ld_canon_sysroot and adjust ld_canon_sysroot_len. 2018-02-28 11:44:26 +00:00
ldmain.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ldmisc.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldmisc.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ldver.c Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
ldver.h
ldwrite.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldwrite.h
lexsup.c ld error/warning messages 2018-02-26 10:51:12 +10:30
MAINTAINERS
Makefile.am ld message translation for emultempl and emulparams 2018-02-26 10:51:12 +10:30
Makefile.in ld message translation for emultempl and emulparams 2018-02-26 10:51:12 +10:30
mri.c ld error/warning messages 2018-02-26 10:51:12 +10:30
mri.h
NEWS ld: Add --enable-separate-code 2018-02-27 11:34:29 -08:00
pe-dll.c Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
pe-dll.h Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
pep-dll.c Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
pep-dll.h Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
plugin.c ld error/warning messages 2018-02-26 10:51:12 +10:30
plugin.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
README Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
stamp-h.in
sysdep.h Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
testplug2.c Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
testplug3.c Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
testplug4.c
testplug.c Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
TODO 19990502 sourceware import 1999-05-03 07:29:11 +00:00

This file contains invisible Unicode characters

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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.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) 2012-2018 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.