gcc/libiberty
Andrew Burgess a87954610f libiberty/buildargv: POSIX behaviour for backslash handling
GDB makes use of the libiberty function buildargv for splitting the
inferior (program being debugged) argument string in the case where
the inferior is not being started under a shell.

I have recently been working to improve this area of GDB, and have
tracked done some of the unexpected behaviour to the libiberty
function buildargv, and how it handles backslash escapes.

For reference, I've been mostly reading:

  https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html

The issues that I would like to fix are:

  1. Backslashes within single quotes should not be treated as an
  escape, thus: '\a' should split to \a, retaining the backslash.

  2. Backslashes within double quotes should only act as an escape if
  they are immediately before one of the characters $ (dollar),
  ` (backtick), " (double quote), ` (backslash), or \n (newline).  In
  all other cases a backslash should not be treated as an escape
  character.  Thus: "\a" should split to \a, but "\$" should split to
  $.

  3. A backslash-newline sequence should be treated as a line
  continuation, both the backslash and the newline should be removed.

I've updated libiberty and also added some tests.  All the existing
libiberty tests continue to pass, but I'm not sure if there is more
testing that should be done, buildargv is used within lto-wraper.cc,
so maybe there's some testing folk can suggest that I run?

2024-07-16  Andrew Burgess  <aburgess@redhat.com>

libiberty/

	* argv.c (buildargv): Backslashes within single quotes are
	literal, backslashes only escape POSIX defined special characters
	within double quotes, and backslashed newlines should act as line
	continuations.
	* testsuite/test-expandargv.c: Add new tests 7, 8, and 9.
2024-07-16 13:51:15 +01:00
..
config
testsuite libiberty/buildargv: POSIX behaviour for backslash handling 2024-07-16 13:51:15 +01:00
_doprnt.c Update copyright years. 2024-01-03 12:19:35 +01:00
.gitignore
acinclude.m4 Update copyright years. 2024-01-03 12:19:35 +01:00
aclocal.m4 libiberty: Disable hwcaps for sha1.o 2023-11-30 10:06:23 +01:00
alloca.c
argv.c libiberty/buildargv: POSIX behaviour for backslash handling 2024-07-16 13:51:15 +01:00
asprintf.c Update copyright years. 2024-01-03 12:19:35 +01:00
at-file.texi
atexit.c
basename.c
bcmp.c
bcopy.c
bsearch_r.c
bsearch.c
bzero.c
calloc.c
ChangeLog Daily bump. 2024-04-03 00:17:29 +00:00
ChangeLog.jit
choose-temp.c Update copyright years. 2024-01-03 12:19:35 +01:00
clock.c Update copyright years. 2024-01-03 12:19:35 +01:00
concat.c Update copyright years. 2024-01-03 12:19:35 +01:00
config.h-vms
config.in libiberty: Use x86 HW optimized sha1 2023-11-28 13:14:05 +01:00
configure libiberty: Fix build with GCC < 7 2023-12-05 23:32:19 +01:00
configure.ac libiberty: Fix build with GCC < 7 2023-12-05 23:32:19 +01:00
configure.com
copying-lib.texi Update copyright years. 2024-01-03 12:19:35 +01:00
COPYING.LIB
copysign.c
cp-demangle.c c++, demangle: Implement https://github.com/itanium-cxx-abi/cxx-abi/issues/148 non-proposal 2024-01-13 10:23:53 +01:00
cp-demangle.h Update copyright years. 2024-01-03 12:19:35 +01:00
cp-demint.c Update copyright years. 2024-01-03 12:19:35 +01:00
cplus-dem.c libiberty: Invoke D demangler when --format=auto 2024-04-02 13:30:19 -06:00
crc32.c Update copyright years. 2024-01-03 12:19:35 +01:00
d-demangle.c Update copyright years. 2024-01-03 12:19:35 +01:00
dwarfnames.c Update copyright years. 2024-01-03 12:19:35 +01:00
dyn-string.c Fix up duplicated words mostly in comments, part 1 2024-04-02 13:39:11 +02:00
fdmatch.c Update copyright years. 2024-01-03 12:19:35 +01:00
ffs.c
fibheap.c Update copyright years. 2024-01-03 12:19:35 +01:00
filedescriptor.c Update copyright years. 2024-01-03 12:19:35 +01:00
filename_cmp.c Update copyright years. 2024-01-03 12:19:35 +01:00
floatformat.c Update copyright years. 2024-01-03 12:19:35 +01:00
fnmatch.c Update copyright years. 2024-01-03 12:19:35 +01:00
fnmatch.txh
fopen_unlocked.c Update copyright years. 2024-01-03 12:19:35 +01:00
functions.texi
gather-docs Update copyright years. 2024-01-03 12:19:35 +01:00
getcwd.c
getopt1.c Update copyright years. 2024-01-03 12:19:35 +01:00
getopt.c Update copyright years. 2024-01-03 12:19:35 +01:00
getpagesize.c
getpwd.c
getruntime.c Update copyright years. 2024-01-03 12:19:35 +01:00
gettimeofday.c
hashtab.c [libiberty] remove TBAA violation in iterative_hash, improve code-gen 2024-02-15 09:14:22 +01:00
hex.c Update copyright years. 2024-01-03 12:19:35 +01:00
index.c
insque.c
lbasename.c Update copyright years. 2024-01-03 12:19:35 +01:00
libiberty.texi Update copyright years. 2024-01-03 12:19:35 +01:00
lrealpath.c Update copyright years. 2024-01-03 12:19:35 +01:00
maint-tool Update copyright years. 2024-01-03 12:19:35 +01:00
make-relative-prefix.c Update copyright years. 2024-01-03 12:19:35 +01:00
make-temp-file.c Update copyright years. 2024-01-03 12:19:35 +01:00
Makefile.in Update copyright years. 2024-01-03 12:19:35 +01:00
makefile.vms
md5.c Update copyright years. 2024-01-03 12:19:35 +01:00
memchr.c
memcmp.c
memcpy.c
memmem.c Update copyright years. 2024-01-03 12:19:35 +01:00
memmove.c
mempcpy.c Update copyright years. 2024-01-03 12:19:35 +01:00
memset.c
mkstemps.c Update copyright years. 2024-01-03 12:19:35 +01:00
msdos.c
objalloc.c Update copyright years. 2024-01-03 12:19:35 +01:00
obstack.c Update copyright years. 2024-01-03 12:19:35 +01:00
obstacks.texi
partition.c Update copyright years. 2024-01-03 12:19:35 +01:00
pex-common.c Update copyright years. 2024-01-03 12:19:35 +01:00
pex-common.h Update copyright years. 2024-01-03 12:19:35 +01:00
pex-djgpp.c Update copyright years. 2024-01-03 12:19:35 +01:00
pex-msdos.c Update copyright years. 2024-01-03 12:19:35 +01:00
pex-one.c Update copyright years. 2024-01-03 12:19:35 +01:00
pex-unix.c libiberty: Fix error return value in pex_unix_exec_child [PR113957]. 2024-02-19 20:13:30 +00:00
pex-win32.c Update copyright years. 2024-01-03 12:19:35 +01:00
pexecute.c Update copyright years. 2024-01-03 12:19:35 +01:00
pexecute.txh
physmem.c Update copyright years. 2024-01-03 12:19:35 +01:00
putenv.c Update copyright years. 2024-01-03 12:19:35 +01:00
random.c
README
regex.c Fix up duplicated words mostly in comments, part 1 2024-04-02 13:39:11 +02:00
rename.c
rindex.c
rust-demangle.c Update copyright years. 2024-01-03 12:19:35 +01:00
safe-ctype.c Update copyright years. 2024-01-03 12:19:35 +01:00
setenv.c Update copyright years. 2024-01-03 12:19:35 +01:00
setproctitle.c Update copyright years. 2024-01-03 12:19:35 +01:00
sha1.c Update copyright years. 2024-01-03 12:19:35 +01:00
sigsetmask.c
simple-object-coff.c Update copyright years. 2024-01-03 12:19:35 +01:00
simple-object-common.h Update copyright years. 2024-01-03 12:19:35 +01:00
simple-object-elf.c Update copyright years. 2024-01-03 12:19:35 +01:00
simple-object-mach-o.c Update copyright years. 2024-01-03 12:19:35 +01:00
simple-object-xcoff.c Update copyright years. 2024-01-03 12:19:35 +01:00
simple-object.c Update copyright years. 2024-01-03 12:19:35 +01:00
simple-object.txh
snprintf.c Update copyright years. 2024-01-03 12:19:35 +01:00
sort.c Update copyright years. 2024-01-03 12:19:35 +01:00
spaces.c Update copyright years. 2024-01-03 12:19:35 +01:00
splay-tree.c Update copyright years. 2024-01-03 12:19:35 +01:00
stack-limit.c Update copyright years. 2024-01-03 12:19:35 +01:00
stpcpy.c Update copyright years. 2024-01-03 12:19:35 +01:00
stpncpy.c Update copyright years. 2024-01-03 12:19:35 +01:00
strcasecmp.c
strchr.c
strdup.c
strerror.c
strncasecmp.c
strncmp.c
strndup.c Update copyright years. 2024-01-03 12:19:35 +01:00
strnlen.c
strrchr.c
strsignal.c
strstr.c
strtod.c Update copyright years. 2024-01-03 12:19:35 +01:00
strtol.c
strtoll.c
strtoul.c
strtoull.c
strverscmp.c Update copyright years. 2024-01-03 12:19:35 +01:00
timeval-utils.c Update copyright years. 2024-01-03 12:19:35 +01:00
tmpnam.c
unlink-if-ordinary.c Update copyright years. 2024-01-03 12:19:35 +01:00
vasprintf.c Update copyright years. 2024-01-03 12:19:35 +01:00
vfork.c
vfprintf.c Update copyright years. 2024-01-03 12:19:35 +01:00
vprintf-support.c libiberty: Fix up libiberty_vprintf_buffer_size 2024-02-12 18:50:16 +01:00
vprintf-support.h Update copyright years. 2024-01-03 12:19:35 +01:00
vprintf.c
vsnprintf.c Update copyright years. 2024-01-03 12:19:35 +01:00
vsprintf.c Update copyright years. 2024-01-03 12:19:35 +01:00
waitpid.c
xasprintf.c Update copyright years. 2024-01-03 12:19:35 +01:00
xatexit.c
xexit.c Update copyright years. 2024-01-03 12:19:35 +01:00
xmalloc.c Update copyright years. 2024-01-03 12:19:35 +01:00
xmemdup.c
xstrdup.c
xstrerror.c
xstrndup.c Update copyright years. 2024-01-03 12:19:35 +01:00
xvasprintf.c Update copyright years. 2024-01-03 12:19:35 +01:00

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.