Re: [PATCH] posix: Fix getconf symbolic constants defined in limits.h (BZ# 29147)

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

Ping.

On 27/05/22 11:31, Adhemerval Zanella wrote:
> POSIX-1.2018 defines that getconf utility shall print symbolic constant
> listed under the heading Maximum value and Minimum Values [1], however
> current behaviour is to print the values using pathconf or sysconf,
> which represents the specific implementation values instead of the
> system agnostics ones.
> 
> Another issue is for such the symbolic constants, getconf handles them
> as a path_var which requires an additional pathname (which does not
> make sense for constants values).
> 
> The patch fixes it adding a new internal type, LIMITS_H, which only
> prints the constant symbolic without requiring an additional path.
> Only the values define in glibc provided limits.h plust the GNU
> extensions are handled.
> 
> Checked on x86_64-linux-gnu.
> 
> [1] https://pubs.opengroup.org/onlinepubs/9699919799/utilities/getconf.html)
> ---
>  posix/Makefile              | 12 ++++++
>  posix/getconf.c             | 86 +++++++++++++++++++++++++++++--------
>  posix/tst-getconf-limits.py | 72 +++++++++++++++++++++++++++++++
>  3 files changed, 153 insertions(+), 17 deletions(-)
>  create mode 100755 posix/tst-getconf-limits.py
> 
> diff --git a/posix/Makefile b/posix/Makefile
> index cfebb8ef06..a21c462e9e 100644
> --- a/posix/Makefile
> +++ b/posix/Makefile
> @@ -175,6 +175,8 @@ tests-special += $(objpfx)bug-regex2-mem.out $(objpfx)bug-regex14-mem.out \
>  		 $(objpfx)bug-glob2-mem.out $(objpfx)tst-vfork3-mem.out \
>  		 $(objpfx)tst-fnmatch-mem.out $(objpfx)bug-regex36-mem.out \
>  		 $(objpfx)tst-glob-tilde-mem.out $(objpfx)bug-ga2-mem.out
> +
> +tests-special += $(objpfx)tst-getconf-limits.out
>  endif
>  
>  include ../Rules
> @@ -404,6 +406,16 @@ $(objpfx)tst-getconf.out: tst-getconf.sh $(objpfx)getconf
>  	$(SHELL) $< $(common-objpfx) '$(built-program-cmd)'; \
>  	$(evaluate-test)
>  
> +$(objpfx)tst-getconf-limits.out: tst-getconf-limits.py $(objpfx)getconf
> +	PYTHONPATH=../scripts \
> +	$(PYTHON) tst-getconf-limits.py \
> +		   --cc="$(CC) $(patsubst -DMODULE_NAME=%, \
> +					  -DMODULE_NAME=testsuite, \
> +					  $(CPPFLAGS)) -D_ISOMAC" \
> +		   '$(built-program-cmd)' \
> +	< /dev/null > $@ 2>&1; $(evaluate-test)
> +
> +
>  $(objpfx)bug-ga2-mem.out: $(objpfx)bug-ga2.out
>  	{ test -r $(objpfx)bug-ga2.mtrace \
>  	|| ( echo "bug-ga2.mtrace does not exist"; exit 77; ) \
> diff --git a/posix/getconf.c b/posix/getconf.c
> index a1adbc4b50..ffd0db234b 100644
> --- a/posix/getconf.c
> +++ b/posix/getconf.c
> @@ -49,24 +49,18 @@
>  struct conf
>    {
>      const char *name;
> -    const int call_name;
> -    const enum { SYSCONF, CONFSTR, PATHCONF } call;
> +    const long int call_name;
> +    const enum { SYSCONF, CONFSTR, PATHCONF, LIMITS_H } call;
>    };
>  
>  static const struct conf vars[] =
>    {
>      { "LINK_MAX", _PC_LINK_MAX, PATHCONF },
> -    { "_POSIX_LINK_MAX", _PC_LINK_MAX, PATHCONF },
>      { "MAX_CANON", _PC_MAX_CANON, PATHCONF },
> -    { "_POSIX_MAX_CANON", _PC_MAX_CANON, PATHCONF },
>      { "MAX_INPUT", _PC_MAX_INPUT, PATHCONF },
> -    { "_POSIX_MAX_INPUT", _PC_MAX_INPUT, PATHCONF },
>      { "NAME_MAX", _PC_NAME_MAX, PATHCONF },
> -    { "_POSIX_NAME_MAX", _PC_NAME_MAX, PATHCONF },
>      { "PATH_MAX", _PC_PATH_MAX, PATHCONF },
> -    { "_POSIX_PATH_MAX", _PC_PATH_MAX, PATHCONF },
>      { "PIPE_BUF", _PC_PIPE_BUF, PATHCONF },
> -    { "_POSIX_PIPE_BUF", _PC_PIPE_BUF, PATHCONF },
>      { "SOCK_MAXBUF", _PC_SOCK_MAXBUF, PATHCONF },
>      { "_POSIX_ASYNC_IO", _PC_ASYNC_IO, PATHCONF },
>      { "_POSIX_CHOWN_RESTRICTED", _PC_CHOWN_RESTRICTED, PATHCONF },
> @@ -123,9 +117,7 @@ static const struct conf vars[] =
>      { "_NPROCESSORS_CONF", _SC_NPROCESSORS_CONF, SYSCONF },
>      { "_NPROCESSORS_ONLN", _SC_NPROCESSORS_ONLN, SYSCONF },
>      { "_PHYS_PAGES", _SC_PHYS_PAGES, SYSCONF },
> -    { "_POSIX_ARG_MAX", _SC_ARG_MAX, SYSCONF },
>      { "_POSIX_ASYNCHRONOUS_IO", _SC_ASYNCHRONOUS_IO, SYSCONF },
> -    { "_POSIX_CHILD_MAX", _SC_CHILD_MAX, SYSCONF },
>      { "_POSIX_FSYNC", _SC_FSYNC, SYSCONF },
>      { "_POSIX_JOB_CONTROL", _SC_JOB_CONTROL, SYSCONF },
>      { "_POSIX_MAPPED_FILES", _SC_MAPPED_FILES, SYSCONF },
> @@ -133,8 +125,6 @@ static const struct conf vars[] =
>      { "_POSIX_MEMLOCK_RANGE", _SC_MEMLOCK_RANGE, SYSCONF },
>      { "_POSIX_MEMORY_PROTECTION", _SC_MEMORY_PROTECTION, SYSCONF },
>      { "_POSIX_MESSAGE_PASSING", _SC_MESSAGE_PASSING, SYSCONF },
> -    { "_POSIX_NGROUPS_MAX", _SC_NGROUPS_MAX, SYSCONF },
> -    { "_POSIX_OPEN_MAX", _SC_OPEN_MAX, SYSCONF },
>      { "_POSIX_PII", _SC_PII, SYSCONF },
>      { "_POSIX_PII_INTERNET", _SC_PII_INTERNET, SYSCONF },
>      { "_POSIX_PII_INTERNET_DGRAM", _SC_PII_INTERNET_DGRAM, SYSCONF },
> @@ -153,8 +143,6 @@ static const struct conf vars[] =
>      { "_POSIX_SELECT", _SC_SELECT, SYSCONF },
>      { "_POSIX_SEMAPHORES", _SC_SEMAPHORES, SYSCONF },
>      { "_POSIX_SHARED_MEMORY_OBJECTS", _SC_SHARED_MEMORY_OBJECTS, SYSCONF },
> -    { "_POSIX_SSIZE_MAX", _SC_SSIZE_MAX, SYSCONF },
> -    { "_POSIX_STREAM_MAX", _SC_STREAM_MAX, SYSCONF },
>      { "_POSIX_SYNCHRONIZED_IO", _SC_SYNCHRONIZED_IO, SYSCONF },
>      { "_POSIX_THREADS", _SC_THREADS, SYSCONF },
>      { "_POSIX_THREAD_ATTR_STACKADDR", _SC_THREAD_ATTR_STACKADDR, SYSCONF },
> @@ -170,7 +158,6 @@ static const struct conf vars[] =
>      { "_POSIX_THREAD_SAFE_FUNCTIONS", _SC_THREAD_SAFE_FUNCTIONS, SYSCONF },
>      { "_POSIX_TIMERS", _SC_TIMERS, SYSCONF },
>      { "TIMER_MAX", _SC_TIMER_MAX, SYSCONF },
> -    { "_POSIX_TZNAME_MAX", _SC_TZNAME_MAX, SYSCONF },
>      { "_POSIX_VERSION", _SC_VERSION, SYSCONF },
>      { "_T_IOV_MAX", _SC_T_IOV_MAX, SYSCONF },
>      { "_XOPEN_CRYPT", _SC_XOPEN_CRYPT, SYSCONF },
> @@ -207,7 +194,6 @@ static const struct conf vars[] =
>      { "POSIX2_EXPR_NEST_MAX", _SC_EXPR_NEST_MAX, SYSCONF },
>      { "POSIX2_FORT_DEV", _SC_2_FORT_DEV, SYSCONF },
>      { "POSIX2_FORT_RUN", _SC_2_FORT_RUN, SYSCONF },
> -    { "_POSIX2_LINE_MAX", _SC_LINE_MAX, SYSCONF },
>      { "POSIX2_LINE_MAX", _SC_LINE_MAX, SYSCONF },
>      { "POSIX2_LOCALEDEF", _SC_2_LOCALEDEF, SYSCONF },
>      { "POSIX2_RE_DUP_MAX", _SC_RE_DUP_MAX, SYSCONF },
> @@ -403,6 +389,63 @@ static const struct conf vars[] =
>      { "_POSIX_IPV6", _SC_IPV6, SYSCONF },
>      { "_POSIX_RAW_SOCKETS", _SC_RAW_SOCKETS, SYSCONF },
>  
> +    /* limits.h symbolic constants.  */
> +#define DEF_LIMIT_H(name) { #name, name, LIMITS_H }
> +    /* Maximum Values.  */
> +    DEF_LIMIT_H (_POSIX_CLOCKRES_MIN),
> +
> +    /* Minimum Values.  */
> +    DEF_LIMIT_H (_POSIX_AIO_LISTIO_MAX),
> +    DEF_LIMIT_H (_POSIX_AIO_MAX),
> +    DEF_LIMIT_H (_POSIX_ARG_MAX),
> +    DEF_LIMIT_H (_POSIX_CHILD_MAX),
> +    DEF_LIMIT_H (_POSIX_DELAYTIMER_MAX),
> +    DEF_LIMIT_H (_POSIX_HOST_NAME_MAX),
> +    DEF_LIMIT_H (_POSIX_LINK_MAX),
> +    DEF_LIMIT_H (_POSIX_LOGIN_NAME_MAX),
> +    DEF_LIMIT_H (_POSIX_MAX_CANON),
> +    DEF_LIMIT_H (_POSIX_MAX_INPUT),
> +    DEF_LIMIT_H (_POSIX_MQ_OPEN_MAX),
> +    DEF_LIMIT_H (_POSIX_MQ_PRIO_MAX),
> +    DEF_LIMIT_H (_POSIX_NAME_MAX),
> +    DEF_LIMIT_H (_POSIX_NGROUPS_MAX),
> +    DEF_LIMIT_H (_POSIX_OPEN_MAX),
> +    DEF_LIMIT_H (_POSIX_PATH_MAX),
> +    DEF_LIMIT_H (_POSIX_PIPE_BUF),
> +    DEF_LIMIT_H (_POSIX_RE_DUP_MAX),
> +    DEF_LIMIT_H (_POSIX_RTSIG_MAX),
> +    DEF_LIMIT_H (_POSIX_SEM_NSEMS_MAX),
> +    DEF_LIMIT_H (_POSIX_SEM_VALUE_MAX),
> +    DEF_LIMIT_H (_POSIX_SIGQUEUE_MAX),
> +    DEF_LIMIT_H (_POSIX_SSIZE_MAX),
> +    DEF_LIMIT_H (_POSIX_STREAM_MAX),
> +    DEF_LIMIT_H (_POSIX_SYMLINK_MAX),
> +    DEF_LIMIT_H (_POSIX_SYMLOOP_MAX),
> +    DEF_LIMIT_H (_POSIX_THREAD_DESTRUCTOR_ITERATIONS),
> +    DEF_LIMIT_H (_POSIX_THREAD_KEYS_MAX),
> +    DEF_LIMIT_H (_POSIX_THREAD_THREADS_MAX),
> +    DEF_LIMIT_H (_POSIX_TIMER_MAX),
> +    DEF_LIMIT_H (_POSIX_TTY_NAME_MAX),
> +    DEF_LIMIT_H (_POSIX_TZNAME_MAX),
> +
> +    DEF_LIMIT_H (_POSIX2_BC_BASE_MAX),
> +    DEF_LIMIT_H (_POSIX2_BC_DIM_MAX),
> +    DEF_LIMIT_H (_POSIX2_BC_SCALE_MAX),
> +    DEF_LIMIT_H (_POSIX2_BC_STRING_MAX),
> +    DEF_LIMIT_H (_POSIX2_CHARCLASS_NAME_MAX),
> +    DEF_LIMIT_H (_POSIX2_COLL_WEIGHTS_MAX),
> +    DEF_LIMIT_H (_POSIX2_EXPR_NEST_MAX),
> +    DEF_LIMIT_H (_POSIX2_LINE_MAX),
> +    DEF_LIMIT_H (_POSIX2_RE_DUP_MAX),
> +
> +    DEF_LIMIT_H (_XOPEN_IOV_MAX),
> +
> +    /* GNU extensions.  */
> +    DEF_LIMIT_H (_POSIX_FD_SETSIZE),
> +    DEF_LIMIT_H (_POSIX_HIWAT),
> +    DEF_LIMIT_H (_POSIX_QLIMIT),
> +    DEF_LIMIT_H (_POSIX_UIO_MAXIOV),
> +
>      { NULL, 0, SYSCONF }
>    };
>  
> @@ -430,7 +473,7 @@ print_all (const char *path)
>    long int value;
>    char *cvalue;
>    for (c = vars; c->name != NULL; ++c) {
> -    printf("%-35s", c->name);
> +    printf("%-36s", c->name);
>      switch (c->call) {
>        case PATHCONF:
>  	value = pathconf (path, c->call_name);
> @@ -461,6 +504,9 @@ print_all (const char *path)
>  	printf ("%.*s\n", (int) clen, cvalue);
>  	free (cvalue);
>  	break;
> +      case LIMITS_H:
> +	printf ("%ld\n", c->call_name);
> +	break;
>      }
>    }
>    exit (0);
> @@ -701,6 +747,12 @@ environment SPEC.\n\n"));
>  
>  	    printf ("%.*s\n", (int) clen, cvalue);
>  	    exit (0);
> +
> +	  case LIMITS_H:
> +	    if (argc - ai > 1)
> +	      usage ();
> +	    printf ("%ld\n", c->call_name);
> +	    exit (0);
>  	  }
>        }
>  
> diff --git a/posix/tst-getconf-limits.py b/posix/tst-getconf-limits.py
> new file mode 100755
> index 0000000000..b64b02f134
> --- /dev/null
> +++ b/posix/tst-getconf-limits.py
> @@ -0,0 +1,72 @@
> +#!/usr/bin/python3
> +#
> +# Test if getconf returns the symbolic constants defined in limits.h.
> +# Copyright (C) 2020-2022 Free Software Foundation, Inc.
> +# This file is part of the GNU C Library.
> +#
> +# The GNU C Library is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU Lesser General Public
> +# License as published by the Free Software Foundation; either
> +# version 2.1 of the License, or (at your option) any later version.
> +#
> +# The GNU C Library is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +# Lesser General Public License for more details.
> +#
> +# You should have received a copy of the GNU Lesser General Public
> +# License along with the GNU C Library; if not, see
> +# <https://www.gnu.org/licenses/>.
> +
> +import argparse
> +import glibcextract
> +import re
> +import subprocess
> +import sys
> +
> +
> +def parse_getconf(cmd):
> +    getconf_out = subprocess.run(cmd + ['-a'], stdout=subprocess.PIPE,
> +                                 check=True, universal_newlines=True).stdout
> +    getconf_set = {}
> +    for line in getconf_out.splitlines():
> +        fields = line.split()
> +        if len(fields) == 2:
> +            getconf_set[fields[0]] = fields[1]
> +    return getconf_set
> +
> +
> +def main():
> +    """The main entry point."""
> +    parser = argparse.ArgumentParser(
> +        description='Test if getconf returns the symbolic constants defined '
> +        'in limits.h.')
> +    parser.add_argument('--cc', metavar='CC',
> +                        help='C compiler (including options) to use')
> +    parser.add_argument('cmd',
> +                        help='How to run getconf')
> +    args = parser.parse_args()
> +
> +    ctes = glibcextract.compute_macro_consts(
> +            source_text='#include <limits.h>\n',
> +            cc=args.cc,
> +            macro_re='_POSIX.*',
> +            exclude_re='_POSIX_C_SOURCE|_POSIX_SOURCE')
> +
> +    getconf_ctes = parse_getconf (args.cmd.split())
> +
> +    ret = 0
> +    for cte,value in ctes.items():
> +        if cte in getconf_ctes:
> +            if getconf_ctes[cte] != value:
> +                print('Symbol {} is defined as {} on limits.h but getconf shows {}'
> +                      .format(cte, value, getconf_ctes[cte]))
> +                ret = 1;
> +        else:
> +            print('Symbol {} not presented in getconf'.format(cte))
> +            ret = 1;
> +    sys.exit(ret)
> +
> +
> +if __name__ == '__main__':
> +    main()