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GDB currently doesn't build on 32-bit Solaris: * On Solaris 11.4/x86: In file included from /usr/include/sys/procfs.h:26, from /vol/src/gnu/gdb/hg/master/dist/gdb/i386-sol2-nat.c:24: /usr/include/sys/old_procfs.h:31:2: error: #error "Cannot use procfs in the large file compilation environment" #error "Cannot use procfs in the large file compilation environment" ^~~~~ * On Solaris 11.3/x86 there are several more instances of this. The interaction between procfs and large-file support historically has been a royal mess on Solaris: * There are two versions of the procfs interface: ** The old ioctl-based /proc, deprecated and not used any longer in either gdb or binutils. ** The `new' (introduced in Solaris 2.6, 1997) structured /proc. * There are two headers one can possibly include: ** <procfs.h> which only provides the structured /proc, definining _STRUCTURED_PROC=1 and then including ... ** <sys/procfs.h> which defaults to _STRUCTURED_PROC=0, the ioctl-based /proc, but provides structured /proc if _STRUCTURED_PROC == 1. * procfs and the large-file environment didn't go well together: ** Until Solaris 11.3, <sys/procfs.h> would always #error in 32-bit compilations when the large-file environment was active (_FILE_OFFSET_BITS == 64). ** In both Solaris 11.4 and Illumos, this restriction was lifted for structured /proc. So one has to be careful always to define _STRUCTURED_PROC=1 when testing for or using <sys/procfs.h> on Solaris. As the errors above show, this isn't always the case in binutils-gdb right now. Also one may need to disable large-file support for 32-bit compilations on Solaris. config/largefile.m4 meant to do this by wrapping the AC_SYS_LARGEFILE autoconf macro with appropriate checks, yielding ACX_LARGEFILE. Unfortunately the macro doesn't always succeed because it neglects the _STRUCTURED_PROC part. To make things even worse, since GCC 9 g++ predefines _FILE_OFFSET_BITS=64 on Solaris. So even if largefile.m4 deciced not to enable large-file support, this has no effect, breaking the gdb build. This patch addresses all this as follows: * All tests for the <sys/procfs.h> header are made with _STRUCTURED_PROC=1, the definition going into the various config.h files instead of having to make them (and sometimes failing) in the affected sources. * To cope with the g++ predefine of _FILE_OFFSET_BITS=64, -U_FILE_OFFSET_BITS is added to various *_CPPFLAGS variables. It had been far easier to have just #undef _FILE_OFFSET_BITS in config.h, but unfortunately such a construct in config.in is commented by config.status irrespective of indentation and whitespace if large-file support is disabled. I found no way around this and putting the #undef in several global headers for bfd, binutils, ld, and gdb seemed way more invasive. * Last, the applicability check in largefile.m4 was modified only to disable largefile support if really needed. To do so, it checks if <sys/procfs.h> compiles with _FILE_OFFSET_BITS=64 defined. If it doesn't, the disabling only happens if gdb exists in-tree and isn't disabled, otherwise (building binutils from a tarball), there's no conflict. What initially confused me was the check for $plugins here, which originally caused the disabling not to take place. Since AC_PLUGINGS does enable plugin support if <dlfcn.h> exists (which it does on Solaris), the disabling never happened. I could find no explanation why the linker plugin needs large-file support but thought it would be enough if gld and GCC's lto-plugin agreed on the _FILE_OFFSET_BITS value. Unfortunately, that's not enough: lto-plugin uses the simple-object interface from libiberty, which includes off_t arguments. So to fully disable large-file support would mean also disabling it in libiberty and its users: gcc and libstdc++-v3. This seems highly undesirable, so I decided to disable the linker plugin instead if large-file support won't work. The patch allows binutils+gdb to build on i386-pc-solaris2.11 (both Solaris 11.3 and 11.4, using GCC 9.3.0 which is the worst case due to predefined _FILE_OFFSET_BITS=64). Also regtested on amd64-pc-solaris2.11 (again on Solaris 11.3 and 11.4), x86_64-pc-linux-gnu and i686-pc-linux-gnu. config: * largefile.m4 (ACX_LARGEFILE) <sparc-*-solaris*|i?86-*-solaris*>: Check for <sys/procfs.h> incompatilibity with large-file support on Solaris. Only disable large-file support and perhaps plugins if needed. Set, substitute LARGEFILE_CPPFLAGS if so. bfd: * bfd.m4 (BFD_SYS_PROCFS_H): New macro. (BFD_HAVE_SYS_PROCFS_TYPE): Require BFD_SYS_PROCFS_H. Don't define _STRUCTURED_PROC. (BFD_HAVE_SYS_PROCFS_TYPE_MEMBER): Likewise. * elf.c [HAVE_SYS_PROCFS_H] (_STRUCTURED_PROC): Don't define. * configure.ac: Use BFD_SYS_PROCFS_H to check for <sys/procfs.h>. * configure, config.in: Regenerate. * Makefile.am (AM_CPPFLAGS): Add LARGEFILE_CPPFLAGS. * Makefile.in, doc/Makefile.in: Regenerate. binutils: * Makefile.am (AM_CPPFLAGS): Add LARGEFILE_CPPFLAGS. * Makefile.in, doc/Makefile.in: Regenerate. * configure: Regenerate. gas: * Makefile.am (AM_CPPFLAGS): Add LARGEFILE_CPPFLAGS. * Makefile.in, doc/Makefile.in: Regenerate. * configure: Regenerate. gdb: * proc-api.c (_STRUCTURED_PROC): Don't define. * proc-events.c: Likewise. * proc-flags.c: Likewise. * proc-why.c: Likewise. * procfs.c: Likewise. * Makefile.in (INTERNAL_CPPFLAGS): Add LARGEFILE_CPPFLAGS. * configure, config.in: Regenerate. gdbserver: * configure, config.in: Regenerate. gdbsupport: * Makefile.am (AM_CPPFLAGS): Add LARGEFILE_CPPFLAGS. * common.m4 (GDB_AC_COMMON): Use BFD_SYS_PROCFS_H to check for <sys/procfs.h>. * Makefile.in: Regenerate. * configure, config.in: Regenerate. gnulib: * configure.ac: Run ACX_LARGEFILE before gl_EARLY. * configure: Regenerate. gprof: * Makefile.am (AM_CPPFLAGS): Add LARGEFILE_CPPFLAGS. * Makefile.in: Regenerate. * configure: Regenerate. ld: * Makefile.am (AM_CPPFLAGS): Add LARGEFILE_CPPFLAGS. * Makefile.in: Regenerate. * configure: Regenerate. |
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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.