text: /* Shell format strings.
     Copyright (C) 2003-2004, 2006-2007, 2009 Free Software Foundation, Inc.
     Written by Bruno Haible <bruno@clisp.org>, 2003.
  
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 3 of the License, or
     (at your option) any later version.
  
     This program 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 General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  
  #ifdef HAVE_CONFIG_H
  # include <config.h>
  #endif
  
  #include <stdbool.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include "format.h"
  #include "c-ctype.h"
  #include "xalloc.h"
  #include "format-invalid.h"
  #include "gettext.h"
  
  #define _(str) gettext (str)
  
  /* Shell format strings are simply strings subjects to variable substitution.
     A variable substitution starts with '$' and is finished by either
     - a nonempty sequence of alphanumeric ASCII characters, the first being
       not a digit, or
     - an opening brace '{', a nonempty sequence of alphanumeric ASCII
       characters, the first being not a digit, and a closing brace '}'.
     We don't support variable references like $1, $$ or $? since they make
     no sense when 'envsubst' is invoked.
     We don't support non-ASCII variable names, to avoid dependencies w.r.t. the
     current encoding: While "${\xe0}" looks like a variable access in ISO-8859-1
     encoding, it doesn't look like one in the BIG5, BIG5-HKSCS, GBK, GB18030,
     SHIFT_JIS, JOHAB encodings, because \xe0\x7d is a single character in these
     encodings.
     We don't support the POSIX syntax for default or alternate values:
       ${variable-default}        ${variable:-default}
       ${variable=default}        ${variable:=default}
       ${variable+replacement}    ${variable:+replacement}
       ${variable?ignored}        ${variable:?ignored}
     because the translator might be tempted to change the default value; if
     we allow it we have a security problem; if we don't allow it the translator
     will be surprised.
   */
  
  struct named_arg
  {
    char *name;
  };
  
  struct spec
  {
    unsigned int directives;
    unsigned int named_arg_count;
    unsigned int allocated;
    struct named_arg *named;
  };
  
  
  static int
  named_arg_compare (const void *p1, const void *p2)
  {
    return strcmp (((const struct named_arg *) p1)->name,
                   ((const struct named_arg *) p2)->name);
  }
  
  #define INVALID_NON_ASCII_VARIABLE() \
    xstrdup (_("The string refers to a shell variable with a non-ASCII name."))
  #define INVALID_SHELL_SYNTAX() \
    xstrdup (_("The string refers to a shell variable with complex shell brace syntax. This syntax is unsupported here due to security reasons."))
  #define INVALID_CONTEXT_DEPENDENT_VARIABLE() \
    xstrdup (_("The string refers to a shell variable whose value may be different inside shell functions."))
  #define INVALID_EMPTY_VARIABLE() \
    xstrdup (_("The string refers to a shell variable with an empty name."))
  
  static void *
  format_parse (const char *format, bool translated, char *fdi,
                char **invalid_reason)
  {
    const char *const format_start = format;
    struct spec spec;
    struct spec *result;
  
    spec.directives = 0;
    spec.named_arg_count = 0;
    spec.allocated = 0;
    spec.named = NULL;
  
    for (; *format != '\0';)
      if (*format++ == '$')
        {
          /* A variable substitution.  */
          char *name;
  
          FDI_SET (format - 1, FMTDIR_START);
          spec.directives++;
  
          if (*format == '{')
            {
              const char *name_start;
              const char *name_end;
              size_t n;
  
              name_start = ++format;
              for (; *format != '\0'; format++)
                {
                  if (*format == '}')
                    break;
                  if (!c_isascii (*format))
                    {
                      *invalid_reason = INVALID_NON_ASCII_VARIABLE ();
                      FDI_SET (format, FMTDIR_ERROR);
                      goto bad_format;
                    }
                  if (format > name_start
                      && (*format == '-' || *format == '=' || *format == '+'
                          || *format == '?' || *format == ':'))
                    {
                      *invalid_reason = INVALID_SHELL_SYNTAX ();
                      FDI_SET (format, FMTDIR_ERROR);
                      goto bad_format;
                    }
                  if (!(c_isalnum (*format) || *format == '_')
                      || (format == name_start && c_isdigit (*format)))
                    {
                      *invalid_reason = INVALID_CONTEXT_DEPENDENT_VARIABLE ();
                      FDI_SET (format, FMTDIR_ERROR);
                      goto bad_format;
                    }
                }
              if (*format == '\0')
                {
                  *invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
                  FDI_SET (format - 1, FMTDIR_ERROR);
                  goto bad_format;
                }
              name_end = format++;
  
              n = name_end - name_start;
              if (n == 0)
                {
                  *invalid_reason = INVALID_EMPTY_VARIABLE ();
                  FDI_SET (format - 1, FMTDIR_ERROR);
                  goto bad_format;
                }
              name = XNMALLOC (n + 1, char);
              memcpy (name, name_start, n);
              name[n] = '\0';
            }
          else if (c_isalpha (*format) || *format == '_')
            {
              const char *name_start;
              const char *name_end;
              size_t n;
  
              name_start = format;
              do
                format++;
              while (*format != '\0' && (c_isalnum (*format) || *format == '_'));
              name_end = format;
  
              n = name_end - name_start;
              name = XNMALLOC (n + 1, char);
              memcpy (name, name_start, n);
              name[n] = '\0';
            }
          else if (*format != '\0')
            {
              if (!c_isascii (*format))
                {
                  *invalid_reason = INVALID_NON_ASCII_VARIABLE ();
                  FDI_SET (format, FMTDIR_ERROR);
                  goto bad_format;
                }
              else
                {
                  *invalid_reason = INVALID_CONTEXT_DEPENDENT_VARIABLE ();
                  FDI_SET (format, FMTDIR_ERROR);
                  goto bad_format;
                }
            }
          else
            {
              *invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
              FDI_SET (format - 1, FMTDIR_ERROR);
              goto bad_format;
            }
  
          /* Named argument.  */
          if (spec.allocated == spec.named_arg_count)
            {
              spec.allocated = 2 * spec.allocated + 1;
              spec.named = (struct named_arg *) xrealloc (spec.named, spec.allocated * sizeof (struct named_arg));
            }
          spec.named[spec.named_arg_count].name = name;
          spec.named_arg_count++;
  
          FDI_SET (format - 1, FMTDIR_END);
        }
  
    /* Sort the named argument array, and eliminate duplicates.  */
    if (spec.named_arg_count > 1)
      {
        unsigned int i, j;
  
        qsort (spec.named, spec.named_arg_count, sizeof (struct named_arg),
               named_arg_compare);
  
        /* Remove duplicates: Copy from i to j, keeping 0 <= j <= i.  */
        for (i = j = 0; i < spec.named_arg_count; i++)
          if (j > 0 && strcmp (spec.named[i].name, spec.named[j-1].name) == 0)
            free (spec.named[i].name);
          else
            {
              if (j < i)
                spec.named[j].name = spec.named[i].name;
              j++;
            }
        spec.named_arg_count = j;
      }
  
    result = XMALLOC (struct spec);
    *result = spec;
    return result;
  
   bad_format:
    if (spec.named != NULL)
      {
        unsigned int i;
        for (i = 0; i < spec.named_arg_count; i++)
          free (spec.named[i].name);
        free (spec.named);
      }
    return NULL;
  }
  
  static void
  format_free (void *descr)
  {
    struct spec *spec = (struct spec *) descr;
  
    if (spec->named != NULL)
      {
        unsigned int i;
        for (i = 0; i < spec->named_arg_count; i++)
          free (spec->named[i].name);
        free (spec->named);
      }
    free (spec);
  }
  
  static int
  format_get_number_of_directives (void *descr)
  {
    struct spec *spec = (struct spec *) descr;
  
    return spec->directives;
  }
  
  static bool
  format_check (void *msgid_descr, void *msgstr_descr, bool equality,
                formatstring_error_logger_t error_logger,
                const char *pretty_msgid, const char *pretty_msgstr)
  {
    struct spec *spec1 = (struct spec *) msgid_descr;
    struct spec *spec2 = (struct spec *) msgstr_descr;
    bool err = false;
  
    if (spec1->named_arg_count + spec2->named_arg_count > 0)
      {
        unsigned int i, j;
        unsigned int n1 = spec1->named_arg_count;
        unsigned int n2 = spec2->named_arg_count;
  
        /* Check the argument names are the same.
           Both arrays are sorted.  We search for the first difference.  */
        for (i = 0, j = 0; i < n1 || j < n2; )
          {
            int cmp = (i >= n1 ? 1 :
                       j >= n2 ? -1 :
                       strcmp (spec1->named[i].name, spec2->named[j].name));
  
            if (cmp > 0)
              {
                if (error_logger)
                  error_logger (_("a format specification for argument '%s', as in '%s', doesn't exist in '%s'"),
                                spec2->named[j].name, pretty_msgstr,
                                pretty_msgid);
                err = true;
                break;
              }
            else if (cmp < 0)
              {
                if (equality)
                  {
                    if (error_logger)
                      error_logger (_("a format specification for argument '%s' doesn't exist in '%s'"),
                                    spec1->named[i].name, pretty_msgstr);
                    err = true;
                    break;
                  }
                else
                  i++;
              }
            else
              j++, i++;
          }
      }
  
    return err;
  }
  
  
  struct formatstring_parser formatstring_sh =
  {
    format_parse,
    format_free,
    format_get_number_of_directives,
    NULL,
    format_check
  };
  
  
  #ifdef TEST
  
  /* Test program: Print the argument list specification returned by
     format_parse for strings read from standard input.  */
  
  #include <stdio.h>
  
  static void
  format_print (void *descr)
  {
    struct spec *spec = (struct spec *) descr;
    unsigned int i;
  
    if (spec == NULL)
      {
        printf ("INVALID");
        return;
      }
  
    printf ("{");
    for (i = 0; i < spec->named_arg_count; i++)
      {
        if (i > 0)
          printf (", ");
        printf ("'%s'", spec->named[i].name);
      }
    printf ("}");
  }
  
  int
  main ()
  {
    for (;;)
      {
        char *line = NULL;
        size_t line_size = 0;
        int line_len;
        char *invalid_reason;
        void *descr;
  
        line_len = getline (&line, &line_size, stdin);
        if (line_len < 0)
          break;
        if (line_len > 0 && line[line_len - 1] == '\n')
          line[--line_len] = '\0';
  
        invalid_reason = NULL;
        descr = format_parse (line, false, NULL, &invalid_reason);
  
        format_print (descr);
        printf ("\n");
        if (descr == NULL)
          printf ("%s\n", invalid_reason);
  
        free (invalid_reason);
        free (line);
      }
  
    return 0;
  }
  
  /*
   * For Emacs M-x compile
   * Local Variables:
   * compile-command: "/bin/sh ../libtool --tag=CC --mode=link gcc -o a.out -static -O -g -Wall -I.. -I../gnulib-lib -I../intl -DHAVE_CONFIG_H -DTEST format-sh.c ../gnulib-lib/libgettextlib.la"
   * End:
   */
  
  #endif /* TEST */
  