gettext-tools/src/x-elisp.c

/* xgettext Emacs Lisp backend.
   Copyright (C) 2001-2003, 2005-2007 Free Software Foundation, Inc.

   This file was written by Bruno Haible <haible@clisp.cons.org>, 2001-2002.

   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

/* Specification.  */
#include "x-elisp.h"

#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "message.h"
#include "xgettext.h"
#include "x-elisp.h"
#include "error.h"
#include "xalloc.h"
#include "hash.h"
#include "c-ctype.h"
#include "gettext.h"

#define _(s) gettext(s)


/* Summary of Emacs Lisp syntax:
   - ';' starts a comment until end of line.
   - '#@nn' starts a comment of nn bytes.
   - Integers are constituted of an optional prefix (#b, #B for binary,
     #o, #O for octal, #x, #X for hexadecimal, #nnr, #nnR for any radix),
     an optional sign (+ or -), the digits, and an optional trailing dot.
   - Characters are written as '?' followed by the character, possibly
     with an escape sequence, for examples '?a', '?\n', '?\177'.
   - Strings are delimited by double quotes. Backslash introduces an escape
     sequence. The following are understood: '\n', '\r', '\f', '\t', '\a',
     '\\', '\^C', '\012' (octal), '\x12' (hexadecimal).
   - Symbols: can contain meta-characters if preceded by backslash.
   - Uninterned symbols: written as #:SYMBOL.
   - () delimit lists.
   - [] delimit vectors.
   The reader is implemented in emacs-21.1/src/lread.c.  */


/* ====================== Keyword set customization.  ====================== */

/* If true extract all strings.  */
static bool extract_all = false;

static hash_table keywords;
static bool default_keywords = true;


void
x_elisp_extract_all ()
{
  extract_all = true;
}


void
x_elisp_keyword (const char *name)
{
  if (name == NULL)
    default_keywords = false;
  else
    {
      const char *end;
      struct callshape shape;
      const char *colon;

      if (keywords.table == NULL)
	hash_init (&keywords, 100);

      split_keywordspec (name, &end, &shape);

      /* The characters between name and end should form a valid Lisp
	 symbol.  */
      colon = strchr (name, ':');
      if (colon == NULL || colon >= end)
	insert_keyword_callshape (&keywords, name, end - name, &shape);
    }
}

/* Finish initializing the keywords hash table.
   Called after argument processing, before each file is processed.  */
static void
init_keywords ()
{
  if (default_keywords)
    {
      /* When adding new keywords here, also update the documentation in
	 xgettext.texi!  */
      x_elisp_keyword ("_");
      default_keywords = false;
    }
}

void
init_flag_table_elisp ()
{
  xgettext_record_flag ("_:1:pass-elisp-format");
  xgettext_record_flag ("format:1:elisp-format");
}


/* ======================== Reading of characters.  ======================== */

/* Real filename, used in error messages about the input file.  */
static const char *real_file_name;

/* Logical filename and line number, used to label the extracted messages.  */
static char *logical_file_name;
static int line_number;

/* The input file stream.  */
static FILE *fp;


/* Fetch the next character from the input file.  */
static int
do_getc ()
{
  int c = getc (fp);

  if (c == EOF)
    {
      if (ferror (fp))
	error (EXIT_FAILURE, errno, _("\
error while reading \"%s\""), real_file_name);
    }
  else if (c == '\n')
   line_number++;

  return c;
}

/* Put back the last fetched character, not EOF.  */
static void
do_ungetc (int c)
{
  if (c == '\n')
    line_number--;
  ungetc (c, fp);
}


/* ========================== Reading of tokens.  ========================== */


/* A token consists of a sequence of characters.  */
struct token
{
  int allocated;		/* number of allocated 'token_char's */
  int charcount;		/* number of used 'token_char's */
  char *chars;			/* the token's constituents */
};

/* Initialize a 'struct token'.  */
static inline void
init_token (struct token *tp)
{
  tp->allocated = 10;
  tp->chars = XNMALLOC (tp->allocated, char);
  tp->charcount = 0;
}

/* Free the memory pointed to by a 'struct token'.  */
static inline void
free_token (struct token *tp)
{
  free (tp->chars);
}

/* Ensure there is enough room in the token for one more character.  */
static inline void
grow_token (struct token *tp)
{
  if (tp->charcount == tp->allocated)
    {
      tp->allocated *= 2;
      tp->chars = (char *) xrealloc (tp->chars, tp->allocated * sizeof (char));
    }
}

/* Test whether a token has integer syntax.  */
static inline bool
is_integer (const char *p)
{
  /* NB: Yes, '+.' and '-.' both designate the integer 0.  */
  const char *p_start = p;

  if (*p == '+' || *p == '-')
    p++;
  if (*p == '\0')
    return false;
  while (*p >= '0' && *p <= '9')
    p++;
  if (p > p_start && *p == '.')
    p++;
  return (*p == '\0');
}

/* Test whether a token has float syntax.  */
static inline bool
is_float (const char *p)
{
  enum { LEAD_INT = 1, DOT_CHAR = 2, TRAIL_INT = 4, E_CHAR = 8, EXP_INT = 16 };
  int state;

  state = 0;
  if (*p == '+' || *p == '-')
    p++;
  if (*p >= '0' && *p <= '9')
    {
      state |= LEAD_INT;
      do
	p++;
      while (*p >= '0' && *p <= '9');
    }
  if (*p == '.')
    {
      state |= DOT_CHAR;
      p++;
    }
  if (*p >= '0' && *p <= '9')
    {
      state |= TRAIL_INT;
      do
	p++;
      while (*p >= '0' && *p <= '9');
    }
  if (*p == 'e' || *p == 'E')
    {
      state |= E_CHAR;
      p++;
      if (*p == '+' || *p == '-')
	p++;
      if (*p >= '0' && *p <= '9')
	{
	  state |= EXP_INT;
	  do
	    p++;
	  while (*p >= '0' && *p <= '9');
	}
      else if (p[-1] == '+'
	       && ((p[0] == 'I' && p[1] == 'N' && p[2] == 'F')
		   || (p[0] == 'N' && p[1] == 'a' && p[2] == 'N')))
	{
	  state |= EXP_INT;
	  p += 3;
	}
    }
  return (*p == '\0')
	 && (state == (LEAD_INT | DOT_CHAR | TRAIL_INT)
	     || state == (DOT_CHAR | TRAIL_INT)
	     || state == (LEAD_INT | E_CHAR | EXP_INT)
	     || state == (LEAD_INT | DOT_CHAR | TRAIL_INT | E_CHAR | EXP_INT)
	     || state == (DOT_CHAR | TRAIL_INT | E_CHAR | EXP_INT));
}

/* Read the next token.  'first' is the first character, which has already
   been read.  Returns true for a symbol, false for a number.  */
static bool
read_token (struct token *tp, int first)
{
  int c;
  bool quoted = false;

  init_token (tp);

  c = first;

  for (;; c = do_getc ())
    {
      if (c == EOF)
	break;
      if (c <= ' ') /* FIXME: Assumes ASCII compatible encoding */
	break;
      if (c == '\"' || c == '\'' || c == ';' || c == '(' || c == ')'
	  || c == '[' || c == ']' || c == '#')
	break;
      if (c == '\\')
	{
	  quoted = true;
	  c = do_getc ();
	  if (c == EOF)
	    /* Invalid, but be tolerant.  */
	    break;
	}
      grow_token (tp);
      tp->chars[tp->charcount++] = c;
    }
  if (c != EOF)
    do_ungetc (c);

  if (quoted)
    return true; /* symbol */

  /* Add a NUL byte at the end, for is_integer and is_float.  */
  grow_token (tp);
  tp->chars[tp->charcount] = '\0';

  if (is_integer (tp->chars) || is_float (tp->chars))
    return false; /* number */
  else
    return true; /* symbol */
}


/* ========================= Accumulating comments ========================= */


static char *buffer;
static size_t bufmax;
static size_t buflen;

static inline void
comment_start ()
{
  buflen = 0;
}

static inline void
comment_add (int c)
{
  if (buflen >= bufmax)
    {
      bufmax = 2 * bufmax + 10;
      buffer = xrealloc (buffer, bufmax);
    }
  buffer[buflen++] = c;
}

static inline void
comment_line_end (size_t chars_to_remove)
{
  buflen -= chars_to_remove;
  while (buflen >= 1
	 && (buffer[buflen - 1] == ' ' || buffer[buflen - 1] == '\t'))
    --buflen;
  if (chars_to_remove == 0 && buflen >= bufmax)
    {
      bufmax = 2 * bufmax + 10;
      buffer = xrealloc (buffer, bufmax);
    }
  buffer[buflen] = '\0';
  savable_comment_add (buffer);
}


/* These are for tracking whether comments count as immediately before
   keyword.  */
static int last_comment_line;
static int last_non_comment_line;


/* ========================= Accumulating messages ========================= */


static message_list_ty *mlp;


/* ============== Reading of objects.  See CLHS 2 "Syntax".  ============== */


/* We are only interested in symbols (e.g. GETTEXT or NGETTEXT) and strings.
   Other objects need not to be represented precisely.  */
enum object_type
{
  t_symbol,	/* symbol */
  t_string,	/* string */
  t_other,	/* other kind of real object */
  t_dot,	/* '.' pseudo object */
  t_listclose,	/* ')' pseudo object */
  t_vectorclose,/* ']' pseudo object */
  t_eof		/* EOF marker */
};

struct object
{
  enum object_type type;
  struct token *token;		/* for t_symbol and t_string */
  int line_number_at_start;	/* for t_string */
};

/* Free the memory pointed to by a 'struct object'.  */
static inline void
free_object (struct object *op)
{
  if (op->type == t_symbol || op->type == t_string)
    {
      free_token (op->token);
      free (op->token);
    }
}

/* Convert a t_symbol/t_string token to a char*.  */
static char *
string_of_object (const struct object *op)
{
  char *str;
  int n;

  if (!(op->type == t_symbol || op->type == t_string))
    abort ();
  n = op->token->charcount;
  str = XNMALLOC (n + 1, char);
  memcpy (str, op->token->chars, n);
  str[n] = '\0';
  return str;
}

/* Context lookup table.  */
static flag_context_list_table_ty *flag_context_list_table;

/* Returns the character represented by an escape sequence.  */
#define IGNORABLE_ESCAPE (EOF - 1)
static int
do_getc_escaped (int c, bool in_string)
{
  switch (c)
    {
    case 'a':
      return '\a';
    case 'b':
      return '\b';
    case 'd':
      return 0x7F;
    case 'e':
      return 0x1B;
    case 'f':
      return '\f';
    case 'n':
      return '\n';
    case 'r':
      return '\r';
    case 't':
      return '\t';
    case 'v':
      return '\v';

    case '\n':
      return IGNORABLE_ESCAPE;

    case ' ':
      return (in_string ? IGNORABLE_ESCAPE : ' ');

    case 'M': /* meta */
      c = do_getc ();
      if (c == EOF)
	return EOF;
      if (c != '-')
	/* Invalid input.  But be tolerant.  */
	return c;
      c = do_getc ();
      if (c == EOF)
	return EOF;
      if (c == '\\')
	{
	  c = do_getc ();
	  if (c == EOF)
	    return EOF;
	  c = do_getc_escaped (c, false);
	}
      return c | 0x80;

    case 'S': /* shift */
      c = do_getc ();
      if (c == EOF)
	return EOF;
      if (c != '-')
	/* Invalid input.  But be tolerant.  */
	return c;
      c = do_getc ();
      if (c == EOF)
	return EOF;
      if (c == '\\')
	{
	  c = do_getc ();
	  if (c == EOF)
	    return EOF;
	  c = do_getc_escaped (c, false);
	}
      return (c >= 'a' && c <= 'z' ? c - 'a' + 'A' : c);

    case 'H': /* hyper */
    case 'A': /* alt */
    case 's': /* super */
      c = do_getc ();
      if (c == EOF)
	return EOF;
      if (c != '-')
	/* Invalid input.  But be tolerant.  */
	return c;
      c = do_getc ();
      if (c == EOF)
	return EOF;
      if (c == '\\')
	{
	  c = do_getc ();
	  if (c == EOF)
	    return EOF;
	  c = do_getc_escaped (c, false);
	}
      return c;

    case 'C': /* ctrl */
      c = do_getc ();
      if (c == EOF)
	return EOF;
      if (c != '-')
	/* Invalid input.  But be tolerant.  */
	return c;
      /*FALLTHROUGH*/
    case '^':
      c = do_getc ();
      if (c == EOF)
	return EOF;
      if (c == '\\')
	{
	  c = do_getc ();
	  if (c == EOF)
	    return EOF;
	  c = do_getc_escaped (c, false);
	}
      if (c == '?')
	return 0x7F;
      if ((c & 0x5F) >= 0x41 && (c & 0x5F) <= 0x5A)
	return c & 0x9F;
      if ((c & 0x7F) >= 0x40 && (c & 0x7F) <= 0x5F)
	return c & 0x9F;
#if 0 /* We cannot handle NUL bytes in strings.  */
      if (c == ' ')
	return 0x00;
#endif
      return c;

    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7':
      /* An octal escape, as in ANSI C.  */
      {
	int n = c - '0';

	c = do_getc ();
	if (c != EOF)
	  {
	    if (c >= '0' && c <= '7')
	      {
		n = (n << 3) + (c - '0');
		c = do_getc ();
		if (c != EOF)
		  {
		    if (c >= '0' && c <= '7')
		      n = (n << 3) + (c - '0');
		    else
		      do_ungetc (c);
		  }
	      }
	    else
	      do_ungetc (c);
	  }
	return (unsigned char) n;
      }

    case 'x':
      /* A hexadecimal escape, as in ANSI C.  */
      {
	int n = 0;

	for (;;)
	  {
	    c = do_getc ();
	    if (c == EOF)
	      break;
	    else if (c >= '0' && c <= '9')
	      n = (n << 4) + (c - '0');
	    else if (c >= 'A' && c <= 'F')
	      n = (n << 4) + (c - 'A' + 10);
	    else if (c >= 'a' && c <= 'f')
	      n = (n << 4) + (c - 'a' + 10);
	    else
	      {
		do_ungetc (c);
		break;
	      }
	  }
	return (unsigned char) n;
      }

    default:
      /* Ignore Emacs multibyte character stuff.  All the strings we are
	 interested in are ASCII strings.  */
      return c;
    }
}

/* Read the next object.
   'first_in_list' and 'new_backquote_flag' are used for reading old
   backquote syntax and new backquote syntax.  */
static void
read_object (struct object *op, bool first_in_list, bool new_backquote_flag,
	     flag_context_ty outer_context)
{
  for (;;)
    {
      int c;

      c = do_getc ();

      switch (c)
	{
	case EOF:
	  op->type = t_eof;
	  return;

	case '\n':
	  /* Comments assumed to be grouped with a message must immediately
	     precede it, with no non-whitespace token on a line between
	     both.  */
	  if (last_non_comment_line > last_comment_line)
	    savable_comment_reset ();
	  continue;

	case '(':
	  {
	    int arg = 0;		/* Current argument number.  */
	    flag_context_list_iterator_ty context_iter;
	    const struct callshapes *shapes = NULL;
	    struct arglist_parser *argparser = NULL;

	    for (;; arg++)
	      {
		struct object inner;
		flag_context_ty inner_context;

		if (arg == 0)
		  inner_context = null_context;
		else
		  inner_context =
		    inherited_context (outer_context,
				       flag_context_list_iterator_advance (
					 &context_iter));

		read_object (&inner, arg == 0, new_backquote_flag,
			     inner_context);

		/* Recognize end of list.  */
		if (inner.type == t_listclose)
		  {
		    op->type = t_other;
		    /* Don't bother converting "()" to "NIL".  */
		    last_non_comment_line = line_number;
		    if (argparser != NULL)
		      arglist_parser_done (argparser, arg);
		    return;
		  }

		/* Dots are not allowed in every position. ']' is not allowed.
		   But be tolerant.  */

		/* EOF inside list is illegal.  But be tolerant.  */
		if (inner.type == t_eof)
		  break;

		if (arg == 0)
		  {
		    /* This is the function position.  */
		    if (inner.type == t_symbol)
		      {
			char *symbol_name = string_of_object (&inner);
			void *keyword_value;

			if (hash_find_entry (&keywords,
					     symbol_name, strlen (symbol_name),
					     &keyword_value)
			    == 0)
			  shapes = (const struct callshapes *) keyword_value;

			argparser = arglist_parser_alloc (mlp, shapes);

			context_iter =
			  flag_context_list_iterator (
			    flag_context_list_table_lookup (
			      flag_context_list_table,
			      symbol_name, strlen (symbol_name)));

			free (symbol_name);
		      }
		    else
		      context_iter = null_context_list_iterator;
		  }
		else
		  {
		    /* These are the argument positions.  */
		    if (argparser != NULL && inner.type == t_string)
		      arglist_parser_remember (argparser, arg,
					       string_of_object (&inner),
					       inner_context,
					       logical_file_name,
					       inner.line_number_at_start,
					       savable_comment);
		  }

		free_object (&inner);
	      }

	    if (argparser != NULL)
	      arglist_parser_done (argparser, arg);
	  }
	  op->type = t_other;
	  last_non_comment_line = line_number;
	  return;

	case ')':
	  /* Tell the caller about the end of list.
	     Unmatched closing parenthesis is illegal.  But be tolerant.  */
	  op->type = t_listclose;
	  last_non_comment_line = line_number;
	  return;

	case '[':
	  {
	    for (;;)
	      {
		struct object inner;

		read_object (&inner, false, new_backquote_flag, null_context);

		/* Recognize end of vector.  */
		if (inner.type == t_vectorclose)
		  {
		    op->type = t_other;
		    last_non_comment_line = line_number;
		    return;
		  }

		/* Dots and ')' are not allowed.  But be tolerant.  */

		/* EOF inside vector is illegal.  But be tolerant.  */
		if (inner.type == t_eof)
		  break;

		free_object (&inner);
	      }
	  }
	  op->type = t_other;
	  last_non_comment_line = line_number;
	  return;

	case ']':
	  /* Tell the caller about the end of vector.
	     Unmatched closing bracket is illegal.  But be tolerant.  */
	  op->type = t_vectorclose;
	  last_non_comment_line = line_number;
	  return;

	case '\'':
	  {
	    struct object inner;

	    read_object (&inner, false, new_backquote_flag, null_context);

	    /* Dots and EOF are not allowed here.  But be tolerant.  */

	    free_object (&inner);

	    op->type = t_other;
	    last_non_comment_line = line_number;
	    return;
	  }

	case '`':
	  if (first_in_list)
	    goto default_label;
	  {
	    struct object inner;

	    read_object (&inner, false, true, null_context);

	    /* Dots and EOF are not allowed here.  But be tolerant.  */

	    free_object (&inner);

	    op->type = t_other;
	    last_non_comment_line = line_number;
	    return;
	  }

	case ',':
	  if (!new_backquote_flag)
	    goto default_label;
	  {
	    int c = do_getc ();
	    /* The ,@ handling inside lists is wrong anyway, because
	       ,@form expands to an unknown number of elements.  */
	    if (c != EOF && c != '@' && c != '.')
	      do_ungetc (c);
	  }
	  {
	    struct object inner;

	    read_object (&inner, false, false, null_context);

	    /* Dots and EOF are not allowed here.  But be tolerant.  */

	    free_object (&inner);

	    op->type = t_other;
	    last_non_comment_line = line_number;
	    return;
	  }

	case ';':
	  {
	    bool all_semicolons = true;

	    last_comment_line = line_number;
	    comment_start ();
	    for (;;)
	      {
		int c = do_getc ();
		if (c == EOF || c == '\n')
		  break;
		if (c != ';')
		  all_semicolons = false;
		if (!all_semicolons)
		  {
		    /* We skip all leading white space, but not EOLs.  */
		    if (!(buflen == 0 && (c == ' ' || c == '\t')))
		      comment_add (c);
		  }
	      }
	    comment_line_end (0);
	    continue;
	  }

	case '"':
	  {
	    op->token = XMALLOC (struct token);
	    init_token (op->token);
	    op->line_number_at_start = line_number;
	    for (;;)
	      {
		int c = do_getc ();
		if (c == EOF)
		  /* Invalid input.  Be tolerant, no error message.  */
		  break;
		if (c == '"')
		  break;
		if (c == '\\')
		  {
		    c = do_getc ();
		    if (c == EOF)
		      /* Invalid input.  Be tolerant, no error message.  */
		      break;
		    c = do_getc_escaped (c, true);
		    if (c == EOF)
		      /* Invalid input.  Be tolerant, no error message.  */
		      break;
		    if (c == IGNORABLE_ESCAPE)
		      /* Ignore escaped newline and escaped space.  */
		      ;
		    else
		      {
			grow_token (op->token);
			op->token->chars[op->token->charcount++] = c;
		      }
		  }
		else
		  {
		    grow_token (op->token);
		    op->token->chars[op->token->charcount++] = c;
		  }
	      }
	    op->type = t_string;

	    if (extract_all)
	      {
		lex_pos_ty pos;

		pos.file_name = logical_file_name;
		pos.line_number = op->line_number_at_start;
		remember_a_message (mlp, NULL, string_of_object (op),
				    null_context, &pos, savable_comment);
	      }
	    last_non_comment_line = line_number;
	    return;
	  }

	case '?':
	  c = do_getc ();
	  if (c == EOF)
	    /* Invalid input.  Be tolerant, no error message.  */
	    ;
	  else if (c == '\\')
	    {
	      c = do_getc ();
	      if (c == EOF)
		/* Invalid input.  Be tolerant, no error message.  */
		;
	      else
		{
		  c = do_getc_escaped (c, false);
		  if (c == EOF)
		    /* Invalid input.  Be tolerant, no error message.  */
		    ;
		}
	    }
	  /* Impossible to deal with Emacs multibyte character stuff here.  */
	  op->type = t_other;
	  last_non_comment_line = line_number;
	  return;

	case '#':
	  /* Dispatch macro handling.  */
	  c = do_getc ();
	  if (c == EOF)
	    /* Invalid input.  Be tolerant, no error message.  */
	    {
	      op->type = t_other;
	      return;
	    }

	  switch (c)
	    {
	    case '^':
	      c = do_getc ();
	      if (c == '^')
		c = do_getc ();
	      if (c == '[')
		{
		  /* Read a char table, same syntax as a vector.  */
		  for (;;)
		    {
		      struct object inner;

		      read_object (&inner, false, new_backquote_flag,
				   null_context);

		      /* Recognize end of vector.  */
		      if (inner.type == t_vectorclose)
			{
			  op->type = t_other;
			  last_non_comment_line = line_number;
			  return;
			}

		      /* Dots and ')' are not allowed.  But be tolerant.  */

		      /* EOF inside vector is illegal.  But be tolerant.  */
		      if (inner.type == t_eof)
			break;

		      free_object (&inner);
		    }
		  op->type = t_other;
		  last_non_comment_line = line_number;
		  return;
		}
	      else
		/* Invalid input.  Be tolerant, no error message.  */
		{
		  op->type = t_other;
		  if (c != EOF)
		    last_non_comment_line = line_number;
		  return;
		}

	    case '&':
	      /* Read a bit vector.  */
	      {
		struct object length;
		read_object (&length, first_in_list, new_backquote_flag,
			     null_context);
		/* Dots and EOF are not allowed here.
		   But be tolerant.  */
		free_object (&length);
	      }
	      c = do_getc ();
	      if (c == '"')
		{
		  struct object string;
		  read_object (&string, first_in_list, new_backquote_flag,
			       null_context);
		  free_object (&string);
		}
	      else
		/* Invalid input.  Be tolerant, no error message.  */
		do_ungetc (c);
	      op->type = t_other;
	      last_non_comment_line = line_number;
	      return;

	    case '[':
	      /* Read a compiled function, same syntax as a vector.  */
	    case '(':
	      /* Read a string with properties, same syntax as a list.  */
	      {
		struct object inner;
		do_ungetc (c);
		read_object (&inner, false, new_backquote_flag, null_context);
		/* Dots and EOF are not allowed here.
		   But be tolerant.  */
		free_object (&inner);
		op->type = t_other;
		last_non_comment_line = line_number;
		return;
	      }

	    case '@':
	      /* Read a comment consisting of a given number of bytes.  */
	      {
		unsigned int nskip = 0;

		for (;;)
		  {
		    c = do_getc ();
		    if (!(c >= '0' && c <= '9'))
		      break;
		    nskip = 10 * nskip + (c - '0');
		  }
		if (c != EOF)
		  {
		    do_ungetc (c);
		    for (; nskip > 0; nskip--)
		      if (do_getc () == EOF)
			break;
		  }
		continue;
	      }

	    case '$':
	      op->type = t_other;
	      last_non_comment_line = line_number;
	      return;

	    case '\'':
	    case ':':
	    case 'S': case 's': /* XEmacs only */
	      {
		struct object inner;
		read_object (&inner, false, new_backquote_flag, null_context);
		/* Dots and EOF are not allowed here.
		   But be tolerant.  */
		free_object (&inner);
		op->type = t_other;
		last_non_comment_line = line_number;
		return;
	      }

	    case '0': case '1': case '2': case '3': case '4':
	    case '5': case '6': case '7': case '8': case '9':
	      /* Read Common Lisp style #n# or #n=.  */
	      for (;;)
		{
		  c = do_getc ();
		  if (!(c >= '0' && c <= '9'))
		    break;
		}
	      if (c == EOF)
		/* Invalid input.  Be tolerant, no error message.  */
		{
		  op->type = t_other;
		  return;
		}
	      if (c == '=')
		{
		  read_object (op, false, new_backquote_flag, outer_context);
		  last_non_comment_line = line_number;
		  return;
		}
	      if (c == '#')
		{
		  op->type = t_other;
		  last_non_comment_line = line_number;
		  return;
		}
	      if (c == 'R' || c == 'r')
		{
		  /* Read an integer.  */
		  c = do_getc ();
		  if (c == '+' || c == '-')
		    c = do_getc ();
		  for (; c != EOF; c = do_getc ())
		    if (!c_isalnum (c))
		      {
			do_ungetc (c);
			break;
		      }
		  op->type = t_other;
		  last_non_comment_line = line_number;
		  return;
		}
	      /* Invalid input.  Be tolerant, no error message.  */
	      op->type = t_other;
	      last_non_comment_line = line_number;
	      return;

	    case 'X': case 'x':
	    case 'O': case 'o':
	    case 'B': case 'b':
	      {
		/* Read an integer.  */
		c = do_getc ();
		if (c == '+' || c == '-')
		  c = do_getc ();
		for (; c != EOF; c = do_getc ())
		  if (!c_isalnum (c))
		    {
		      do_ungetc (c);
		      break;
		    }
		op->type = t_other;
		last_non_comment_line = line_number;
		return;
	      }

	    case '*': /* XEmacs only */
	      {
		/* Read a bit-vector.  */
		do
		  c = do_getc ();
		while (c == '0' || c == '1');
		if (c != EOF)
		  do_ungetc (c);
		op->type = t_other;
		last_non_comment_line = line_number;
		return;
	      }

	    case '+': /* XEmacs only */
	    case '-': /* XEmacs only */
	      /* Simply assume every feature expression is true.  */
	      {
		struct object inner;
		read_object (&inner, false, new_backquote_flag, null_context);
		/* Dots and EOF are not allowed here.
		   But be tolerant.  */
		free_object (&inner);
		continue;
	      }

	    default:
	      /* Invalid input.  Be tolerant, no error message.  */
	      op->type = t_other;
	      last_non_comment_line = line_number;
	      return;
	    }

	  /*NOTREACHED*/
	  abort ();

	case '.':
	  c = do_getc ();
	  if (c != EOF)
	    {
	      do_ungetc (c);
	      if (c <= ' ' /* FIXME: Assumes ASCII compatible encoding */
		  || strchr ("\"'`,(", c) != NULL)
		{
		  op->type = t_dot;
		  last_non_comment_line = line_number;
		  return;
		}
	    }
	  c = '.';
	  /*FALLTHROUGH*/
	default:
	default_label:
	  if (c <= ' ') /* FIXME: Assumes ASCII compatible encoding */
	    continue;
	  /* Read a token.  */
	  {
	    bool symbol;

	    op->token = XMALLOC (struct token);
	    symbol = read_token (op->token, c);
	    if (symbol)
	      {
		op->type = t_symbol;
		last_non_comment_line = line_number;
		return;
	      }
	    else
	      {
		free_token (op->token);
		free (op->token);
		op->type = t_other;
		last_non_comment_line = line_number;
		return;
	      }
	  }
	}
    }
}


void
extract_elisp (FILE *f,
	       const char *real_filename, const char *logical_filename,
	       flag_context_list_table_ty *flag_table,
	       msgdomain_list_ty *mdlp)
{
  mlp = mdlp->item[0]->messages;

  fp = f;
  real_file_name = real_filename;
  logical_file_name = xstrdup (logical_filename);
  line_number = 1;

  last_comment_line = -1;
  last_non_comment_line = -1;

  flag_context_list_table = flag_table;

  init_keywords ();

  /* Eat tokens until eof is seen.  When read_object returns
     due to an unbalanced closing parenthesis, just restart it.  */
  do
    {
      struct object toplevel_object;

      read_object (&toplevel_object, false, false, null_context);

      if (toplevel_object.type == t_eof)
	break;

      free_object (&toplevel_object);
    }
  while (!feof (fp));

  /* Close scanner.  */
  fp = NULL;
  real_file_name = NULL;
  logical_file_name = NULL;
  line_number = 0;
}