gcc/libiberty
Brendan Shanks 879cf9ff45 [PATCH v3] libiberty: Use posix_spawn in pex-unix when available.
Hi,

This patch implements pex_unix_exec_child using posix_spawn when
available.

This should especially benefit recent macOS (where vfork just calls
fork), but should have equivalent or faster performance on all
platforms.
In addition, the implementation is substantially simpler than the
vfork+exec code path.

Tested on x86_64-linux.

v2: Fix error handling (previously the function would be run twice in
case of error), and don't use a macro that changes control flow.

v3: Match file style for error-handling blocks, don't close
in/out/errdes on error, and check close() for errors.

libiberty/
	* configure.ac (AC_CHECK_HEADERS): Add spawn.h.
	(checkfuncs): Add posix_spawn, posix_spawnp.
	(AC_CHECK_FUNCS): Add posix_spawn, posix_spawnp.
	* aclocal.m4, configure, config.in: Rebuild.
	* pex-unix.c [HAVE_POSIX_SPAWN] (pex_unix_exec_child): New function.
2023-11-09 21:01:58 -07:00
..
config
testsuite c++: constrained hidden friends [PR109751] 2023-08-22 14:34:53 -04:00
_doprnt.c
.gitignore
acinclude.m4
aclocal.m4 [PATCH v3] libiberty: Use posix_spawn in pex-unix when available. 2023-11-09 21:01:58 -07:00
alloca.c
argv.c
asprintf.c
at-file.texi
atexit.c
basename.c
bcmp.c
bcopy.c
bsearch_r.c
bsearch.c
bzero.c
calloc.c
ChangeLog Daily bump. 2023-08-23 00:17:59 +00:00
ChangeLog.jit
choose-temp.c
clock.c
concat.c
config.h-vms
config.in [PATCH v3] libiberty: Use posix_spawn in pex-unix when available. 2023-11-09 21:01:58 -07:00
configure [PATCH v3] libiberty: Use posix_spawn in pex-unix when available. 2023-11-09 21:01:58 -07:00
configure.ac [PATCH v3] libiberty: Use posix_spawn in pex-unix when available. 2023-11-09 21:01:58 -07:00
configure.com
copying-lib.texi
COPYING.LIB
copysign.c
cp-demangle.c c++: constrained hidden friends [PR109751] 2023-08-22 14:34:53 -04:00
cp-demangle.h
cp-demint.c
cplus-dem.c
crc32.c
d-demangle.c
dwarfnames.c
dyn-string.c
fdmatch.c
ffs.c
fibheap.c
filedescriptor.c
filename_cmp.c
floatformat.c
fnmatch.c
fnmatch.txh
fopen_unlocked.c
functions.texi
gather-docs
getcwd.c
getopt1.c
getopt.c
getpagesize.c
getpwd.c
getruntime.c
gettimeofday.c
hashtab.c
hex.c
index.c
insque.c
lbasename.c
libiberty.texi
lrealpath.c
maint-tool
make-relative-prefix.c
make-temp-file.c
Makefile.in
makefile.vms
md5.c
memchr.c
memcmp.c
memcpy.c
memmem.c
memmove.c
mempcpy.c
memset.c
mkstemps.c
msdos.c
objalloc.c
obstack.c
obstacks.texi
partition.c
pex-common.c
pex-common.h
pex-djgpp.c
pex-msdos.c
pex-one.c
pex-unix.c [PATCH v3] libiberty: Use posix_spawn in pex-unix when available. 2023-11-09 21:01:58 -07:00
pex-win32.c
pexecute.c
pexecute.txh
physmem.c
putenv.c
random.c
README
regex.c
rename.c
rindex.c
rust-demangle.c
safe-ctype.c
setenv.c
setproctitle.c
sha1.c
sigsetmask.c
simple-object-coff.c
simple-object-common.h
simple-object-elf.c
simple-object-mach-o.c
simple-object-xcoff.c
simple-object.c
simple-object.txh
snprintf.c
sort.c
spaces.c
splay-tree.c
stack-limit.c
stpcpy.c
stpncpy.c
strcasecmp.c
strchr.c
strdup.c
strerror.c
strncasecmp.c
strncmp.c
strndup.c
strnlen.c
strrchr.c
strsignal.c
strstr.c
strtod.c
strtol.c
strtoll.c
strtoul.c
strtoull.c
strverscmp.c
timeval-utils.c
tmpnam.c
unlink-if-ordinary.c
vasprintf.c
vfork.c
vfprintf.c
vprintf-support.c
vprintf-support.h
vprintf.c
vsnprintf.c
vsprintf.c
waitpid.c
xasprintf.c
xatexit.c
xexit.c
xmalloc.c
xmemdup.c
xstrdup.c
xstrerror.c
xstrndup.c
xvasprintf.c

This directory contains the -liberty library of free software.
It is a collection of subroutines used by various GNU programs.
Current members include:

	getopt -- get options from command line
	obstack -- stacks of arbitrarily-sized objects
	strerror -- error message strings corresponding to errno
	strtol -- string-to-long conversion
	strtoul -- string-to-unsigned-long conversion

We expect many of the GNU subroutines that are floating around to
eventually arrive here.

The library must be configured from the top source directory.  Don't
try to run configure in this directory.  Follow the configuration
instructions in ../README.

Please report bugs to https://gcc.gnu.org/bugzilla/ and send fixes to
"gcc-patches@gcc.gnu.org".  Thank you.

ADDING A NEW FILE
=================

There are two sets of files:  Those that are "required" will be
included in the library for all configurations, while those
that are "optional" will be included in the library only if "needed."

To add a new required file, edit Makefile.in to add the source file
name to CFILES and the object file to REQUIRED_OFILES.

To add a new optional file, it must provide a single function, and the
name of the function must be the same as the name of the file.

    * Add the source file name to CFILES in Makefile.in and the object
      file to CONFIGURED_OFILES.

    * Add the function to name to the funcs shell variable in
      configure.ac.

    * Add the function to the AC_CHECK_FUNCS lists just after the
      setting of the funcs shell variable.  These AC_CHECK_FUNCS calls
      are never executed; they are there to make autoheader work
      better.

    * Consider the special cases of building libiberty; as of this
      writing, the special cases are newlib and VxWorks.  If a
      particular special case provides the function, you do not need
      to do anything.  If it does not provide the function, add the
      object file to LIBOBJS, and add the function name to the case
      controlling whether to define HAVE_func.

Finally, in the build directory of libiberty, configure with
"--enable-maintainer-mode", run "make maint-deps" to update
Makefile.in, and run 'make stamp-functions' to regenerate
functions.texi.

The optional file you've added (e.g. getcwd.c) should compile and work
on all hosts where it is needed.  It does not have to work or even
compile on hosts where it is not needed.

ADDING A NEW CONFIGURATION
==========================

On most hosts you should be able to use the scheme for automatically
figuring out which files are needed.  In that case, you probably
don't need a special Makefile stub for that configuration.

If the fully automatic scheme doesn't work, you may be able to get
by with defining EXTRA_OFILES in your Makefile stub.  This is
a list of object file names that should be treated as required
for this configuration - they will be included in libiberty.a,
regardless of whatever might be in the C library.