libtool/libltdl/lt__argz.c

/* lt__argz.c -- argz implementation for non-glibc systems

   Copyright (C) 2004, 2006-2008, 2011-2019, 2021-2024 Free Software
   Foundation, Inc.
   Written by Gary V. Vaughan, 2004

   NOTE: The canonical source of this file is maintained with the
   GNU Libtool package.  Report bugs to bug-libtool@gnu.org.

GNU Libltdl 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 of the License, or (at your option) any later version.

As a special exception to the GNU Lesser General Public License,
if you distribute this file as part of a program or library that
is built using GNU Libtool, you may include this file under the
same distribution terms that you use for the rest of that program.

GNU Libltdl 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 GNU Libltdl.  If not, see <https://www.gnu.org/licenses/>.
*/

#if defined LTDL && defined LT_CONFIG_H
#  include LT_CONFIG_H
#else
#  include <config.h>
#endif

#include <lt__argz.h>

#include <assert.h>
#include <stdlib.h>
#include <sys/types.h>
#include <errno.h>
#include <string.h>

#define EOS_CHAR '\0'

error_t
argz_append (char **pargz, size_t *pargz_len, const char *buf, size_t buf_len)
{
  size_t argz_len;
  char  *argz;

  assert (pargz);
  assert (pargz_len);
  assert ((*pargz && *pargz_len) || (!*pargz && !*pargz_len));

  /* If nothing needs to be appended, no more work is required.  */
  if (buf_len == 0)
    return 0;

  /* Ensure there is enough room to append BUF_LEN.  */
  argz_len = *pargz_len + buf_len;
  argz = (char *) realloc (*pargz, argz_len);
  if (!argz)
    return ENOMEM;

  /* Copy characters from BUF after terminating '\0' in ARGZ.  */
  memcpy (argz + *pargz_len, buf, buf_len);

  /* Assign new values.  */
  *pargz = argz;
  *pargz_len = argz_len;

  return 0;
}


error_t
argz_create_sep (const char *str, int delim, char **pargz, size_t *pargz_len)
{
  size_t argz_len;
  char *argz = 0;

  assert (str);
  assert (pargz);
  assert (pargz_len);

  /* Make a copy of STR, but replacing each occurrence of
     DELIM with '\0'.  */
  argz_len = 1+ strlen (str);
  if (argz_len)
    {
      const char *p;
      char *q;

      argz = (char *) malloc (argz_len);
      if (!argz)
	return ENOMEM;

      for (p = str, q = argz; *p != EOS_CHAR; ++p)
	{
	  if (*p == delim)
	    {
	      /* Ignore leading delimiters, and fold consecutive
		 delimiters in STR into a single '\0' in ARGZ.  */
	      if ((q > argz) && (q[-1] != EOS_CHAR))
		*q++ = EOS_CHAR;
	      else
		--argz_len;
	    }
	  else
	    *q++ = *p;
	}
      /* Copy terminating EOS_CHAR.  */
      *q = *p;
    }

  /* If ARGZ_LEN has shrunk to nothing, release ARGZ's memory.  */
  if (!argz_len)
    argz = (free (argz), (char *) 0);

  /* Assign new values.  */
  *pargz = argz;
  *pargz_len = argz_len;

  return 0;
}


error_t
argz_insert (char **pargz, size_t *pargz_len, char *before, const char *entry)
{
  assert (pargz);
  assert (pargz_len);
  assert (entry && *entry);

  /* No BEFORE address indicates ENTRY should be inserted after the
     current last element.  */
  if (!before)
    return argz_append (pargz, pargz_len, entry, 1+ strlen (entry));

  /* This probably indicates a programmer error, but to preserve
     semantics, scan back to the start of an entry if BEFORE points
     into the middle of it.  */
  while ((before > *pargz) && (before[-1] != EOS_CHAR))
    --before;

  {
    size_t entry_len	= 1+ strlen (entry);
    size_t argz_len	= *pargz_len + entry_len;
    size_t offset	= before - *pargz;
    char   *argz	= (char *) realloc (*pargz, argz_len);

    if (!argz)
      return ENOMEM;

    /* Make BEFORE point to the equivalent offset in ARGZ that it
       used to have in *PARGZ in case realloc() moved the block.  */
    before = argz + offset;

    /* Move the ARGZ entries starting at BEFORE up into the new
       space at the end -- making room to copy ENTRY into the
       resulting gap.  */
    memmove (before + entry_len, before, *pargz_len - offset);
    memcpy  (before, entry, entry_len);

    /* Assign new values.  */
    *pargz = argz;
    *pargz_len = argz_len;
  }

  return 0;
}


char *
argz_next (char *argz, size_t argz_len, const char *entry)
{
  assert ((argz && argz_len) || (!argz && !argz_len));

  if (entry)
    {
      /* Either ARGZ/ARGZ_LEN is empty, or ENTRY points into an address
	 within the ARGZ vector.  */
      assert ((!argz && !argz_len)
	      || ((argz <= entry) && (entry < (argz + argz_len))));

      /* Move to the char immediately after the terminating
	 '\0' of ENTRY.  */
      entry = 1+ strchr (entry, EOS_CHAR);

      /* Return either the new ENTRY, or else NULL if ARGZ is
	 exhausted.  */
      return (entry >= argz + argz_len) ? 0 : (char *) entry;
    }
  else
    {
      /* This should probably be flagged as a programmer error,
	 since starting an argz_next loop with the iterator set
	 to ARGZ is safer.  To preserve semantics, handle the NULL
	 case by returning the start of ARGZ (if any).  */
      if (argz_len > 0)
	return argz;
      else
	return 0;
    }
}


void
argz_stringify (char *argz, size_t argz_len, int sep)
{
  assert ((argz && argz_len) || (!argz && !argz_len));

  if (sep)
    {
      --argz_len;		/* don't stringify the terminating EOS */
      while (--argz_len > 0)
	{
	  if (argz[argz_len] == EOS_CHAR)
	    argz[argz_len] = sep;
	}
    }
}