(scan_c_file): Warn about missing `usage' info.

[bpt/emacs.git] / lib-src / make-docfile.c

/* Generate doc-string file for GNU Emacs from source files.
   Copyright (C) 1985, 86, 92, 93, 94, 97, 1999, 2000, 2001
   Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs 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 2, or (at your option)
any later version.

GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* The arguments given to this program are all the C and Lisp source files
 of GNU Emacs.  .elc and .el and .c files are allowed.
 A .o file can also be specified; the .c file it was made from is used.
 This helps the makefile pass the correct list of files.

 The results, which go to standard output or to a file
 specified with -a or -o (-a to append, -o to start from nothing),
 are entries containing function or variable names and their documentation.
 Each entry starts with a ^_ character.
 Then comes F for a function or V for a variable.
 Then comes the function or variable name, terminated with a newline.
 Then comes the documentation for that function or variable.
 */

#define NO_SHORTNAMES   /* Tell config not to load remap.h */
#include <config.h>

/* defined to be emacs_main, sys_fopen, etc. in config.h */
#undef main
#undef fopen
#undef chdir

#include <stdio.h>
#ifdef MSDOS
#include <fcntl.h>
#endif /* MSDOS */
#ifdef WINDOWSNT
#include <stdlib.h>
#include <fcntl.h>
#include <direct.h>
#endif /* WINDOWSNT */

#ifdef DOS_NT
#define READ_TEXT "rt"
#define READ_BINARY "rb"
#else  /* not DOS_NT */
#define READ_TEXT "r"
#define READ_BINARY "r"
#endif /* not DOS_NT */

int scan_file ();
int scan_lisp_file ();
int scan_c_file ();

#ifdef MSDOS
/* s/msdos.h defines this as sys_chdir, but we're not linking with the
   file where that function is defined.  */
#undef chdir
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

/* Stdio stream for output to the DOC file.  */
FILE *outfile;

/* Name this program was invoked with.  */
char *progname;

/* Print error message.  `s1' is printf control string, `s2' is arg for it.  */

/* VARARGS1 */
void
error (s1, s2)
     char *s1, *s2;
{
  fprintf (stderr, "%s: ", progname);
  fprintf (stderr, s1, s2);
  fprintf (stderr, "\n");
}

/* Print error message and exit.  */

/* VARARGS1 */
void
fatal (s1, s2)
     char *s1, *s2;
{
  error (s1, s2);
  exit (1);
}

/* Like malloc but get fatal error if memory is exhausted.  */

long *
xmalloc (size)
     unsigned int size;
{
  long *result = (long *) malloc (size);
  if (result == NULL)
    fatal ("virtual memory exhausted", 0);
  return result;
}
\f
int
main (argc, argv)
     int argc;
     char **argv;
{
  int i;
  int err_count = 0;
  int first_infile;

  progname = argv[0];

  outfile = stdout;

  /* Don't put CRs in the DOC file.  */
#ifdef MSDOS
  _fmode = O_BINARY;
#if 0  /* Suspicion is that this causes hanging.
          So instead we require people to use -o on MSDOS.  */
  (stdout)->_flag &= ~_IOTEXT;
  _setmode (fileno (stdout), O_BINARY);
#endif
  outfile = 0;
#endif /* MSDOS */
#ifdef WINDOWSNT
  _fmode = O_BINARY;
  _setmode (fileno (stdout), O_BINARY);
#endif /* WINDOWSNT */

  /* If first two args are -o FILE, output to FILE.  */
  i = 1;
  if (argc > i + 1 && !strcmp (argv[i], "-o"))
    {
      outfile = fopen (argv[i + 1], "w");
      i += 2;
    }
  if (argc > i + 1 && !strcmp (argv[i], "-a"))
    {
      outfile = fopen (argv[i + 1], "a");
      i += 2;
    }
  if (argc > i + 1 && !strcmp (argv[i], "-d"))
    {
      chdir (argv[i + 1]);
      i += 2;
    }

  if (outfile == 0)
    fatal ("No output file specified", "");

  first_infile = i;
  for (; i < argc; i++)
    {
      int j;
      /* Don't process one file twice.  */
      for (j = first_infile; j < i; j++)
        if (! strcmp (argv[i], argv[j]))
          break;
      if (j == i)
        err_count += scan_file (argv[i]);
    }
#ifndef VMS
  exit (err_count > 0);
#endif /* VMS */
  return err_count > 0;
}

/* Read file FILENAME and output its doc strings to outfile.  */
/* Return 1 if file is not found, 0 if it is found.  */

int
scan_file (filename)
     char *filename;
{
  int len = strlen (filename);
  if (len > 4 && !strcmp (filename + len - 4, ".elc"))
    return scan_lisp_file (filename, READ_BINARY);
  else if (len > 3 && !strcmp (filename + len - 3, ".el"))
    return scan_lisp_file (filename, READ_TEXT);
  else
    return scan_c_file (filename, READ_TEXT);
}
\f
char buf[128];

/* Some state during the execution of `read_c_string_or_comment'.  */
struct rcsoc_state
{
  /* A count of spaces and newlines that have been read, but not output.  */
  unsigned pending_spaces, pending_newlines;

  /* Where we're reading from.  */
  FILE *in_file;

  /* If non-zero, a buffer into which to copy characters.  */
  char *buf_ptr;
  /* If non-zero, a file into which to copy characters.  */
  FILE *out_file;

  /* A keyword we look for at the beginning of lines.  If found, it is
     not copied, and SAW_KEYWORD is set to true.  */
  char *keyword;
  /* The current point we've reached in an occurance of KEYWORD in
     the input stream.  */
  char *cur_keyword_ptr;
  /* Set to true if we saw an occurance of KEYWORD.  */
  int saw_keyword;
};

/* Output CH to the file or buffer in STATE.  Any pending newlines or
   spaces are output first.  */

static INLINE void
put_char (ch, state)
     int ch;
     struct rcsoc_state *state;
{
  int out_ch;
  do
    {
      if (state->pending_newlines > 0)
        {
          state->pending_newlines--;
          out_ch = '\n';
        }
      else if (state->pending_spaces > 0)
        {
          state->pending_spaces--;
          out_ch = ' ';
        }
      else
        out_ch = ch;

      if (state->out_file)
        putc (out_ch, state->out_file);
      if (state->buf_ptr)
        *state->buf_ptr++ = out_ch;
    }
  while (out_ch != ch);
}

/* If in the middle of scanning a keyword, continue scanning with
   character CH, otherwise output CH to the file or buffer in STATE.
   Any pending newlines or spaces are output first, as well as any
   previously scanned characters that were thought to be part of a
   keyword, but were in fact not.  */

static void
scan_keyword_or_put_char (ch, state)
     int ch;
     struct rcsoc_state *state;
{
  if (state->keyword
      && *state->cur_keyword_ptr == ch
      && (state->cur_keyword_ptr > state->keyword
          || state->pending_newlines > 0))
    /* We might be looking at STATE->keyword at some point.
       Keep looking until we know for sure.  */
    {
      if (*++state->cur_keyword_ptr == '\0')
        /* Saw the whole keyword.  Set SAW_KEYWORD flag to true.  */
        {
          state->saw_keyword = 1;

          /* Reset the scanning pointer.  */
          state->cur_keyword_ptr = state->keyword;

          /* Canonicalize whitespace preceding a usage string.  */
          state->pending_newlines = 2;
          state->pending_spaces = 0;

          /* Skip any whitespace between the keyword and the
             usage string.  */
          do
            ch = getc (state->in_file);
          while (ch == ' ' || ch == '\n');

          /* Put back the non-whitespace character.  */
          ungetc (ch, state->in_file);
        }
    }
  else
    {
      if (state->keyword && state->cur_keyword_ptr > state->keyword)
        /* We scanned the beginning of a potential usage
           keyword, but it was a false alarm.  Output the
           part we scanned.  */
        {
          char *p;

          for (p = state->keyword; p < state->cur_keyword_ptr; p++)
            put_char (*p, state);

          state->cur_keyword_ptr = state->keyword;
        }

      put_char (ch, state);
    }
}


/* Skip a C string or C-style comment from INFILE, and return the
   character that follows.  COMMENT non-zero means skip a comment.  If
   PRINTFLAG is positive, output string contents to outfile.  If it is
   negative, store contents in buf.  Convert escape sequences \n and
   \t to newline and tab; discard \ followed by newline.
   If SAW_USAGE is non-zero, then any occurances of the string `usage:'
   at the beginning of a line will be removed, and *SAW_USAGE set to
   true if any were encountered.  */

int
read_c_string_or_comment (infile, printflag, comment, saw_usage)
     FILE *infile;
     int printflag;
     int *saw_usage;
{
  register int c;
  struct rcsoc_state state;

  state.in_file = infile;
  state.buf_ptr = (printflag < 0 ? buf : 0);
  state.out_file = (printflag > 0 ? outfile : 0);
  state.pending_spaces = 0;
  state.pending_newlines = 0;
  state.keyword = (saw_usage ? "usage:" : 0);
  state.cur_keyword_ptr = state.keyword;
  state.saw_keyword = 0;

  c = getc (infile);
  if (comment)
    while (c == '\n' || c == '\r' || c == '\t' || c == ' ')
      c = getc (infile);

  while (c != EOF)
    {
      while (c != EOF && (comment ? c != '*' : c != '"'))
        {
          if (c == '\\')
            {
              c = getc (infile);
              if (c == '\n' || c == '\r')
                {
                  c = getc (infile);
                  continue;
                }
              if (c == 'n')
                c = '\n';
              if (c == 't')
                c = '\t';
            }

          if (c == ' ')
            state.pending_spaces++;
          else if (c == '\n')
            {
              state.pending_newlines++;
              state.pending_spaces = 0;
            }
          else
            scan_keyword_or_put_char (c, &state);

          c = getc (infile);
        }

      if (c != EOF)
        c = getc (infile);

      if (comment)
        {
          if (c == '/')
            {
              c = getc (infile);
              break;
            }

          scan_keyword_or_put_char ('*', &state);
        }
      else
        {
          if (c != '"')
            break;

          /* If we had a "", concatenate the two strings.  */
          c = getc (infile);
        }
    }

  if (printflag < 0)
    *state.buf_ptr = 0;

  if (saw_usage)
    *saw_usage = state.saw_keyword;

  return c;
}


\f
/* Write to file OUT the argument names of function FUNC, whose text is in BUF.
   MINARGS and MAXARGS are the minimum and maximum number of arguments.  */

void
write_c_args (out, func, buf, minargs, maxargs)
     FILE *out;
     char *func, *buf;
     int minargs, maxargs;
{
  register char *p;
  int in_ident = 0;
  int just_spaced = 0;
  int need_space = 1;

  fprintf (out, "(%s", func);

  if (*buf == '(')
    ++buf;

  for (p = buf; *p; p++)
    {
      char c = *p;
      int ident_start = 0;

      /* Notice when we start printing a new identifier.  */
      if ((('A' <= c && c <= 'Z')
           || ('a' <= c && c <= 'z')
           || ('0' <= c && c <= '9')
           || c == '_')
          != in_ident)
        {
          if (!in_ident)
            {
              in_ident = 1;
              ident_start = 1;

              if (need_space)
                putc (' ', out);

              if (minargs == 0 && maxargs > 0)
                fprintf (out, "&optional ");
              just_spaced = 1;

              minargs--;
              maxargs--;
            }
          else
            in_ident = 0;
        }

      /* Print the C argument list as it would appear in lisp:
         print underscores as hyphens, and print commas and newlines
         as spaces.  Collapse adjacent spaces into one.  */
      if (c == '_')
        c = '-';
      else if (c == ',' || c == '\n')
        c = ' ';

      /* In C code, `default' is a reserved word, so we spell it
         `defalt'; unmangle that here.  */
      if (ident_start
          && strncmp (p, "defalt", 6) == 0
          && ! (('A' <= p[6] && p[6] <= 'Z')
                || ('a' <= p[6] && p[6] <= 'z')
                || ('0' <= p[6] && p[6] <= '9')
                || p[6] == '_'))
        {
          fprintf (out, "DEFAULT");
          p += 5;
          in_ident = 0;
          just_spaced = 0;
        }
      else if (c != ' ' || !just_spaced)
        {
          if (c >= 'a' && c <= 'z')
            /* Upcase the letter.  */
            c += 'A' - 'a';
          putc (c, out);
        }

      just_spaced = c == ' ';
      need_space = 0;
    }
}
\f
/* Read through a c file.  If a .o file is named,
   the corresponding .c file is read instead.
   Looks for DEFUN constructs such as are defined in ../src/lisp.h.
   Accepts any word starting DEF... so it finds DEFSIMPLE and DEFPRED.  */

int
scan_c_file (filename, mode)
     char *filename, *mode;
{
  FILE *infile;
  register int c;
  register int commas;
  register int defunflag;
  register int defvarperbufferflag;
  register int defvarflag;
  int minargs, maxargs;
  int extension = filename[strlen (filename) - 1];

  if (extension == 'o')
    filename[strlen (filename) - 1] = 'c';

  infile = fopen (filename, mode);

  /* No error if non-ex input file */
  if (infile == NULL)
    {
      perror (filename);
      return 0;
    }

  /* Reset extension to be able to detect duplicate files.  */
  filename[strlen (filename) - 1] = extension;

  c = '\n';
  while (!feof (infile))
    {
      int doc_keyword = 0;

      if (c != '\n' && c != '\r')
        {
          c = getc (infile);
          continue;
        }
      c = getc (infile);
      if (c == ' ')
        {
          while (c == ' ')
            c = getc (infile);
          if (c != 'D')
            continue;
          c = getc (infile);
          if (c != 'E')
            continue;
          c = getc (infile);
          if (c != 'F')
            continue;
          c = getc (infile);
          if (c != 'V')
            continue;
          c = getc (infile);
          if (c != 'A')
            continue;
          c = getc (infile);
          if (c != 'R')
            continue;
          c = getc (infile);
          if (c != '_')
            continue;

          defvarflag = 1;
          defunflag = 0;

          c = getc (infile);
          defvarperbufferflag = (c == 'P');

          c = getc (infile);
        }
      else if (c == 'D')
        {
          c = getc (infile);
          if (c != 'E')
            continue;
          c = getc (infile);
          if (c != 'F')
            continue;
          c = getc (infile);
          defunflag = c == 'U';
          defvarflag = 0;
        }
      else continue;

      while (c != '(')
        {
          if (c < 0)
            goto eof;
          c = getc (infile);
        }

      /* Lisp variable or function name.  */
      c = getc (infile);
      if (c != '"')
        continue;
      c = read_c_string_or_comment (infile, -1, 0, 0);

      /* DEFVAR_LISP ("name", addr, "doc")
         DEFVAR_LISP ("name", addr /\* doc *\/)
         DEFVAR_LISP ("name", addr, doc: /\* doc *\/)  */

      if (defunflag)
        commas = 5;
      else if (defvarperbufferflag)
        commas = 2;
      else if (defvarflag)
        commas = 1;
      else  /* For DEFSIMPLE and DEFPRED */
        commas = 2;

      while (commas)
        {
          if (c == ',')
            {
              commas--;

              if (defunflag && (commas == 1 || commas == 2))
                {
                  do
                    c = getc (infile);
                  while (c == ' ' || c == '\n' || c == '\r' || c == '\t');
                  if (c < 0)
                    goto eof;
                  ungetc (c, infile);
                  if (commas == 2) /* pick up minargs */
                    fscanf (infile, "%d", &minargs);
                  else /* pick up maxargs */
                    if (c == 'M' || c == 'U') /* MANY || UNEVALLED */
                      maxargs = -1;
                    else
                      fscanf (infile, "%d", &maxargs);
                }
            }

          if (c == EOF)
            goto eof;
          c = getc (infile);
        }

      while (c == ' ' || c == '\n' || c == '\r' || c == '\t')
        c = getc (infile);

      if (c == '"')
        c = read_c_string_or_comment (infile, 0, 0, 0);

      while (c != EOF && c != ',' && c != '/')
        c = getc (infile);
      if (c == ',')
        {
          c = getc (infile);
          while (c == ' ' || c == '\n' || c == '\r' || c == '\t')
            c = getc (infile);
          while ((c >= 'a' && c <= 'z') || (c >= 'Z' && c <= 'Z'))
            c = getc (infile);
          if (c == ':')
            {
              doc_keyword = 1;
              c = getc (infile);
              while (c == ' ' || c == '\n' || c == '\r' || c == '\t')
                c = getc (infile);
            }
        }

      if (c == '"'
          || (c == '/'
              && (c = getc (infile),
                  ungetc (c, infile),
                  c == '*')))
        {
          int comment = c != '"';
          int saw_usage;

          putc (037, outfile);
          putc (defvarflag ? 'V' : 'F', outfile);
          fprintf (outfile, "%s\n", buf);

          if (comment)
            getc (infile);      /* Skip past `*' */
          c = read_c_string_or_comment (infile, 1, comment, &saw_usage);

          /* If this is a defun, find the arguments and print them.  If
             this function takes MANY or UNEVALLED args, then the C source
             won't give the names of the arguments, so we shouldn't bother
             trying to find them.

             Various doc-string styles:
              0: DEFUN (..., "DOC") (args)            [!comment]
              1: DEFUN (..., /\* DOC *\/ (args))      [comment && !doc_keyword]
              2: DEFUN (..., doc: /\* DOC *\/) (args) [comment && doc_keyword]
          */
          if (defunflag && maxargs != -1 && !saw_usage)
            {
              char argbuf[1024], *p = argbuf;

              if (!comment || doc_keyword)
                while (c != ')')
                  {
                    if (c < 0)
                      goto eof;
                    c = getc (infile);
                  }

              /* Skip into arguments.  */
              while (c != '(')
                {
                  if (c < 0)
                    goto eof;
                  c = getc (infile);
                }
              /* Copy arguments into ARGBUF.  */
              *p++ = c;
              do
                *p++ = c = getc (infile);
              while (c != ')');
              *p = '\0';
              /* Output them.  */
              fprintf (outfile, "\n\n");
              write_c_args (outfile, buf, argbuf, minargs, maxargs);
            }
          else if (defunflag && maxargs == -1 && !saw_usage)
            /* The DOC should provide the usage form.  */
            fprintf (stderr, "Missing `usage' for function `%s'.\n", buf);
        }
    }
 eof:
  fclose (infile);
  return 0;
}
\f
/* Read a file of Lisp code, compiled or interpreted.
 Looks for
  (defun NAME ARGS DOCSTRING ...)
  (defmacro NAME ARGS DOCSTRING ...)
  (defsubst NAME ARGS DOCSTRING ...)
  (autoload (quote NAME) FILE DOCSTRING ...)
  (defvar NAME VALUE DOCSTRING)
  (defconst NAME VALUE DOCSTRING)
  (fset (quote NAME) (make-byte-code ... DOCSTRING ...))
  (fset (quote NAME) #[... DOCSTRING ...])
  (defalias (quote NAME) #[... DOCSTRING ...])
  (custom-declare-variable (quote NAME) VALUE DOCSTRING ...)
 starting in column zero.
 (quote NAME) may appear as 'NAME as well.

 We also look for #@LENGTH CONTENTS^_ at the beginning of the line.
 When we find that, we save it for the following defining-form,
 and we use that instead of reading a doc string within that defining-form.

 For defvar, defconst, and fset we skip to the docstring with a kludgy
 formatting convention: all docstrings must appear on the same line as the
 initial open-paren (the one in column zero) and must contain a backslash
 and a newline immediately after the initial double-quote.  No newlines
 must appear between the beginning of the form and the first double-quote.
 For defun, defmacro, and autoload, we know how to skip over the
 arglist, but the doc string must still have a backslash and newline
 immediately after the double quote.
 The only source files that must follow this convention are preloaded
 uncompiled ones like loaddefs.el and bindings.el; aside
 from that, it is always the .elc file that we look at, and they are no
 problem because byte-compiler output follows this convention.
 The NAME and DOCSTRING are output.
 NAME is preceded by `F' for a function or `V' for a variable.
 An entry is output only if DOCSTRING has \ newline just after the opening "
 */

void
skip_white (infile)
     FILE *infile;
{
  char c = ' ';
  while (c == ' ' || c == '\t' || c == '\n' || c == '\r')
    c = getc (infile);
  ungetc (c, infile);
}

void
read_lisp_symbol (infile, buffer)
     FILE *infile;
     char *buffer;
{
  char c;
  char *fillp = buffer;

  skip_white (infile);
  while (1)
    {
      c = getc (infile);
      if (c == '\\')
        *(++fillp) = getc (infile);
      else if (c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '(' || c == ')')
        {
          ungetc (c, infile);
          *fillp = 0;
          break;
        }
      else
        *fillp++ = c;
    }

  if (! buffer[0])
    fprintf (stderr, "## expected a symbol, got '%c'\n", c);

  skip_white (infile);
}

int
scan_lisp_file (filename, mode)
     char *filename, *mode;
{
  FILE *infile;
  register int c;
  char *saved_string = 0;

  infile = fopen (filename, mode);
  if (infile == NULL)
    {
      perror (filename);
      return 0;                         /* No error */
    }

  c = '\n';
  while (!feof (infile))
    {
      char buffer[BUFSIZ];
      char type;

      /* If not at end of line, skip till we get to one.  */
      if (c != '\n' && c != '\r')
        {
          c = getc (infile);
          continue;
        }
      /* Skip the line break.  */
      while (c == '\n' || c == '\r')
        c = getc (infile);
      /* Detect a dynamic doc string and save it for the next expression.  */
      if (c == '#')
        {
          c = getc (infile);
          if (c == '@')
            {
              int length = 0;
              int i;

              /* Read the length.  */
              while ((c = getc (infile),
                      c >= '0' && c <= '9'))
                {
                  length *= 10;
                  length += c - '0';
                }

              /* The next character is a space that is counted in the length
                 but not part of the doc string.
                 We already read it, so just ignore it.  */
              length--;

              /* Read in the contents.  */
              if (saved_string != 0)
                free (saved_string);
              saved_string = (char *) malloc (length);
              for (i = 0; i < length; i++)
                saved_string[i] = getc (infile);
              /* The last character is a ^_.
                 That is needed in the .elc file
                 but it is redundant in DOC.  So get rid of it here.  */
              saved_string[length - 1] = 0;
              /* Skip the line break.  */
              while (c == '\n' && c == '\r')
                c = getc (infile);
              /* Skip the following line.  */
              while (c != '\n' && c != '\r')
                c = getc (infile);
            }
          continue;
        }

      if (c != '(')
        continue;

      read_lisp_symbol (infile, buffer);

      if (! strcmp (buffer, "defun")
          || ! strcmp (buffer, "defmacro")
          || ! strcmp (buffer, "defsubst"))
        {
          type = 'F';
          read_lisp_symbol (infile, buffer);

          /* Skip the arguments: either "nil" or a list in parens */

          c = getc (infile);
          if (c == 'n') /* nil */
            {
              if ((c = getc (infile)) != 'i'
                  || (c = getc (infile)) != 'l')
                {
                  fprintf (stderr, "## unparsable arglist in %s (%s)\n",
                           buffer, filename);
                  continue;
                }
            }
          else if (c != '(')
            {
              fprintf (stderr, "## unparsable arglist in %s (%s)\n",
                       buffer, filename);
              continue;
            }
          else
            while (c != ')')
              c = getc (infile);
          skip_white (infile);

          /* If the next three characters aren't `dquote bslash newline'
             then we're not reading a docstring.
           */
          if ((c = getc (infile)) != '"'
              || (c = getc (infile)) != '\\'
              || ((c = getc (infile)) != '\n' && c != '\r'))
            {
#ifdef DEBUG
              fprintf (stderr, "## non-docstring in %s (%s)\n",
                       buffer, filename);
#endif
              continue;
            }
        }

      else if (! strcmp (buffer, "defvar")
               || ! strcmp (buffer, "defconst"))
        {
          char c1 = 0, c2 = 0;
          type = 'V';
          read_lisp_symbol (infile, buffer);

          if (saved_string == 0)
            {

              /* Skip until the end of line; remember two previous chars.  */
              while (c != '\n' && c != '\r' && c >= 0)
                {
                  c2 = c1;
                  c1 = c;
                  c = getc (infile);
                }

              /* If two previous characters were " and \,
                 this is a doc string.  Otherwise, there is none.  */
              if (c2 != '"' || c1 != '\\')
                {
#ifdef DEBUG
                  fprintf (stderr, "## non-docstring in %s (%s)\n",
                           buffer, filename);
#endif
                  continue;
                }
            }
        }

      else if (! strcmp (buffer, "custom-declare-variable"))
        {
          char c1 = 0, c2 = 0;
          type = 'V';

          c = getc (infile);
          if (c == '\'')
            read_lisp_symbol (infile, buffer);
          else
            {
              if (c != '(')
                {
                  fprintf (stderr,
                           "## unparsable name in custom-declare-variable in %s\n",
                           filename);
                  continue;
                }
              read_lisp_symbol (infile, buffer);
              if (strcmp (buffer, "quote"))
                {
                  fprintf (stderr,
                           "## unparsable name in custom-declare-variable in %s\n",
                           filename);
                  continue;
                }
              read_lisp_symbol (infile, buffer);
              c = getc (infile);
              if (c != ')')
                {
                  fprintf (stderr,
                           "## unparsable quoted name in custom-declare-variable in %s\n",
                           filename);
                  continue;
                }
            }

          if (saved_string == 0)
            {
              /* Skip to end of line; remember the two previous chars.  */
              while (c != '\n' && c != '\r' && c >= 0)
                {
                  c2 = c1;
                  c1 = c;
                  c = getc (infile);
                }

              /* If two previous characters were " and \,
                 this is a doc string.  Otherwise, there is none.  */
              if (c2 != '"' || c1 != '\\')
                {
#ifdef DEBUG
                  fprintf (stderr, "## non-docstring in %s (%s)\n",
                           buffer, filename);
#endif
                  continue;
                }
            }
        }

      else if (! strcmp (buffer, "fset") || ! strcmp (buffer, "defalias"))
        {
          char c1 = 0, c2 = 0;
          type = 'F';

          c = getc (infile);
          if (c == '\'')
            read_lisp_symbol (infile, buffer);
          else
            {
              if (c != '(')
                {
                  fprintf (stderr, "## unparsable name in fset in %s\n",
                           filename);
                  continue;
                }
              read_lisp_symbol (infile, buffer);
              if (strcmp (buffer, "quote"))
                {
                  fprintf (stderr, "## unparsable name in fset in %s\n",
                           filename);
                  continue;
                }
              read_lisp_symbol (infile, buffer);
              c = getc (infile);
              if (c != ')')
                {
                  fprintf (stderr,
                           "## unparsable quoted name in fset in %s\n",
                           filename);
                  continue;
                }
            }

          if (saved_string == 0)
            {
              /* Skip to end of line; remember the two previous chars.  */
              while (c != '\n' && c != '\r' && c >= 0)
                {
                  c2 = c1;
                  c1 = c;
                  c = getc (infile);
                }

              /* If two previous characters were " and \,
                 this is a doc string.  Otherwise, there is none.  */
              if (c2 != '"' || c1 != '\\')
                {
#ifdef DEBUG
                  fprintf (stderr, "## non-docstring in %s (%s)\n",
                           buffer, filename);
#endif
                  continue;
                }
            }
        }

      else if (! strcmp (buffer, "autoload"))
        {
          type = 'F';
          c = getc (infile);
          if (c == '\'')
            read_lisp_symbol (infile, buffer);
          else
            {
              if (c != '(')
                {
                  fprintf (stderr, "## unparsable name in autoload in %s\n",
                           filename);
                  continue;
                }
              read_lisp_symbol (infile, buffer);
              if (strcmp (buffer, "quote"))
                {
                  fprintf (stderr, "## unparsable name in autoload in %s\n",
                           filename);
                  continue;
                }
              read_lisp_symbol (infile, buffer);
              c = getc (infile);
              if (c != ')')
                {
                  fprintf (stderr,
                           "## unparsable quoted name in autoload in %s\n",
                           filename);
                  continue;
                }
            }
          skip_white (infile);
          if ((c = getc (infile)) != '\"')
            {
              fprintf (stderr, "## autoload of %s unparsable (%s)\n",
                       buffer, filename);
              continue;
            }
          read_c_string_or_comment (infile, 0, 0, 0);
          skip_white (infile);

          if (saved_string == 0)
            {
              /* If the next three characters aren't `dquote bslash newline'
                 then we're not reading a docstring.  */
              if ((c = getc (infile)) != '"'
                  || (c = getc (infile)) != '\\'
                  || ((c = getc (infile)) != '\n' && c != '\r'))
                {
#ifdef DEBUG
                  fprintf (stderr, "## non-docstring in %s (%s)\n",
                           buffer, filename);
#endif
                  continue;
                }
            }
        }

#ifdef DEBUG
      else if (! strcmp (buffer, "if")
               || ! strcmp (buffer, "byte-code"))
        ;
#endif

      else
        {
#ifdef DEBUG
          fprintf (stderr, "## unrecognised top-level form, %s (%s)\n",
                   buffer, filename);
#endif
          continue;
        }

      /* At this point, we should either use the previous
         dynamic doc string in saved_string
         or gobble a doc string from the input file.

         In the latter case, the opening quote (and leading
         backslash-newline) have already been read.  */

      putc (037, outfile);
      putc (type, outfile);
      fprintf (outfile, "%s\n", buffer);
      if (saved_string)
        {
          fputs (saved_string, outfile);
          /* Don't use one dynamic doc string twice.  */
          free (saved_string);
          saved_string = 0;
        }
      else
        read_c_string_or_comment (infile, 1, 0, 0);
    }
  fclose (infile);
  return 0;
}