lread.c 104 KB
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/* Lisp parsing and input streams.
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   Copyright (C) 1985, 86, 87, 88, 89, 93, 94, 95, 97, 98, 99, 2000, 01, 02
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      Free Software Foundation, Inc.
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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
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the Free Software Foundation; either version 2, or (at your option)
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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
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */
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#include <config.h>
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#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
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#include <errno.h>
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#include "lisp.h"
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#include "intervals.h"
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#include "buffer.h"
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#include "character.h"
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#include "charset.h"
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#include "coding.h"
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#include <epaths.h>
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#include "commands.h"
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#include "keyboard.h"
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#include "termhooks.h"
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#ifdef lint
#include <sys/inode.h>
#endif /* lint */

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#ifdef MSDOS
#if __DJGPP__ < 2
#include <unistd.h>	/* to get X_OK */
#endif
#include "msdos.h"
#endif

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

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#ifndef X_OK
#define X_OK 01
#endif

#include <math.h>

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#ifdef HAVE_SETLOCALE
#include <locale.h>
#endif /* HAVE_SETLOCALE */

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#ifndef O_RDONLY
#define O_RDONLY 0
#endif

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#ifdef HAVE_FSEEKO
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#define file_offset off_t
#define file_tell ftello
#else
#define file_offset long
#define file_tell ftell
#endif

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#ifndef USE_CRT_DLL
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extern int errno;
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#endif
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Lisp_Object Qread_char, Qget_file_char, Qstandard_input, Qcurrent_load_list;
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Lisp_Object Qvariable_documentation, Vvalues, Vstandard_input, Vafter_load_alist;
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Lisp_Object Qascii_character, Qload, Qload_file_name;
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Lisp_Object Qbackquote, Qcomma, Qcomma_at, Qcomma_dot, Qfunction;
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Lisp_Object Qinhibit_file_name_operation;
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/* Used instead of Qget_file_char while loading *.elc files compiled
   by Emacs 21 or older.  */
static Lisp_Object Qget_emacs_mule_file_char;

static Lisp_Object Qload_force_doc_strings;

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extern Lisp_Object Qevent_symbol_element_mask;
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extern Lisp_Object Qfile_exists_p;
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/* non-zero if inside `load' */
int load_in_progress;

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/* Directory in which the sources were found.  */
Lisp_Object Vsource_directory;

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/* Search path and suffixes for files to be loaded. */
Lisp_Object Vload_path, Vload_suffixes, default_suffixes;
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/* File name of user's init file.  */
Lisp_Object Vuser_init_file;

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/* This is the user-visible association list that maps features to
   lists of defs in their load files. */
Lisp_Object Vload_history;

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/* This is used to build the load history. */
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Lisp_Object Vcurrent_load_list;

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/* List of files that were preloaded.  */
Lisp_Object Vpreloaded_file_list;

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/* Name of file actually being read by `load'.  */
Lisp_Object Vload_file_name;

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/* Function to use for reading, in `load' and friends.  */
Lisp_Object Vload_read_function;

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/* The association list of objects read with the #n=object form.
   Each member of the list has the form (n . object), and is used to
   look up the object for the corresponding #n# construct.
   It must be set to nil before all top-level calls to read0.  */
Lisp_Object read_objects;

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/* Nonzero means load should forcibly load all dynamic doc strings.  */
static int load_force_doc_strings;

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/* Nonzero means read should convert strings to unibyte.  */
static int load_convert_to_unibyte;

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/* Nonzero means READCHAR should read bytes one by one (not character)
   when READCHARFUN is Qget_file_char or Qget_emacs_mule_file_char.
   This is set to 1 by read1 temporarily while handling #@NUMBER.  */
static int load_each_byte;

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/* Function to use for loading an Emacs lisp source file (not
   compiled) instead of readevalloop.  */
Lisp_Object Vload_source_file_function;

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/* List of all DEFVAR_BOOL variables.  Used by the byte optimizer.  */
Lisp_Object Vbyte_boolean_vars;

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/* List of descriptors now open for Fload.  */
static Lisp_Object load_descriptor_list;

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/* File for get_file_char to read from.  Use by load.  */
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static FILE *instream;

/* When nonzero, read conses in pure space */
static int read_pure;

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/* For use within read-from-string (this reader is non-reentrant!!)  */
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static int read_from_string_index;
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static int read_from_string_index_byte;
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static int read_from_string_limit;
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/* This contains the last string skipped with #@.  */
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static char *saved_doc_string;
/* Length of buffer allocated in saved_doc_string.  */
static int saved_doc_string_size;
/* Length of actual data in saved_doc_string.  */
static int saved_doc_string_length;
/* This is the file position that string came from.  */
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static file_offset saved_doc_string_position;
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/* This contains the previous string skipped with #@.
   We copy it from saved_doc_string when a new string
   is put in saved_doc_string.  */
static char *prev_saved_doc_string;
/* Length of buffer allocated in prev_saved_doc_string.  */
static int prev_saved_doc_string_size;
/* Length of actual data in prev_saved_doc_string.  */
static int prev_saved_doc_string_length;
/* This is the file position that string came from.  */
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static file_offset prev_saved_doc_string_position;
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/* Nonzero means inside a new-style backquote
   with no surrounding parentheses.
   Fread initializes this to zero, so we need not specbind it
   or worry about what happens to it when there is an error.  */
static int new_backquote_flag;
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/* A list of file names for files being loaded in Fload.  Used to
   check for recursive loads.  */

static Lisp_Object Vloads_in_progress;

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/* Non-zero means load dangerous compiled Lisp files.  */

int load_dangerous_libraries;

/* A regular expression used to detect files compiled with Emacs.  */

static Lisp_Object Vbytecomp_version_regexp;

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static int read_emacs_mule_char P_ ((int, int (*) (int, Lisp_Object),
				     Lisp_Object));

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static void readevalloop P_ ((Lisp_Object, FILE*, Lisp_Object, 
			      Lisp_Object (*) (), int,
			      Lisp_Object, Lisp_Object));
static Lisp_Object load_unwind P_ ((Lisp_Object));
static Lisp_Object load_descriptor_unwind P_ ((Lisp_Object));

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/* Functions that read one byte from the current source READCHARFUN
   or unreads one byte.  If the integer argument C is -1, it returns
   one read byte, or -1 when there's no more byte in the source.  If C
   is 0 or positive, it unreads C, and the return value is not
   interesting.  */

static int readbyte_for_lambda P_ ((int, Lisp_Object));
static int readbyte_from_file P_ ((int, Lisp_Object));
static int readbyte_from_string P_ ((int, Lisp_Object));

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/* Handle unreading and rereading of characters.
   Write READCHAR to read a character,
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   UNREAD(c) to unread c to be read again.

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   These macros correctly read/unread multibyte characters.  */
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#define READCHAR readchar (readcharfun)
#define UNREAD(c) unreadchar (readcharfun, c)

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/* When READCHARFUN is Qget_file_char, Qget_emacs_mule_file_char,
   Qlambda, or a cons, we use this to keep unread character because a
   file stream can't handle multibyte-char unreading.  The value -1
   means that there's no unread character. */
static int unread_char;


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static int
readchar (readcharfun)
     Lisp_Object readcharfun;
{
  Lisp_Object tem;
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  register int c;
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  int (*readbyte) P_ ((int, Lisp_Object));
  unsigned char buf[MAX_MULTIBYTE_LENGTH];
  int i, len;
  int emacs_mule_encoding = 0;
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  if (BUFFERP (readcharfun))
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    {
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      register struct buffer *inbuffer = XBUFFER (readcharfun);
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      int pt_byte = BUF_PT_BYTE (inbuffer);
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      if (pt_byte >= BUF_ZV_BYTE (inbuffer))
	return -1;
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      if (! NILP (inbuffer->enable_multibyte_characters))
	{
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	  /* Fetch the character code from the buffer.  */
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	  unsigned char *p = BUF_BYTE_ADDRESS (inbuffer, pt_byte);
	  BUF_INC_POS (inbuffer, pt_byte);
	  c = STRING_CHAR (p, pt_byte - orig_pt_byte);
	}
      else
	{
	  c = BUF_FETCH_BYTE (inbuffer, pt_byte);
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	  if (! ASCII_BYTE_P (c))
	    c = BYTE8_TO_CHAR (c);
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	  pt_byte++;
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	}
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      SET_BUF_PT_BOTH (inbuffer, BUF_PT (inbuffer) + 1, pt_byte);
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      return c;
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    }
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  if (MARKERP (readcharfun))
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    {
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      register struct buffer *inbuffer = XMARKER (readcharfun)->buffer;
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      int bytepos = marker_byte_position (readcharfun);
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      if (bytepos >= BUF_ZV_BYTE (inbuffer))
	return -1;
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      if (! NILP (inbuffer->enable_multibyte_characters))
	{
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	  /* Fetch the character code from the buffer.  */
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	  unsigned char *p = BUF_BYTE_ADDRESS (inbuffer, bytepos);
	  BUF_INC_POS (inbuffer, bytepos);
	  c = STRING_CHAR (p, bytepos - orig_bytepos);
	}
      else
	{
	  c = BUF_FETCH_BYTE (inbuffer, bytepos);
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	  if (! ASCII_BYTE_P (c))
	    c = BYTE8_TO_CHAR (c);
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	  bytepos++;
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	}

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      XMARKER (readcharfun)->bytepos = bytepos;
      XMARKER (readcharfun)->charpos++;

      return c;
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    }
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  if (EQ (readcharfun, Qlambda))
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    {
      readbyte = readbyte_for_lambda;
      goto read_multibyte;
    }
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  if (EQ (readcharfun, Qget_file_char))
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    {
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      readbyte = readbyte_from_file;
      goto read_multibyte;
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    }
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  if (STRINGP (readcharfun))
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    {
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      if (read_from_string_index >= read_from_string_limit)
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	c = -1;
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      else
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	FETCH_STRING_CHAR_ADVANCE (c, readcharfun,
				   read_from_string_index,
				   read_from_string_index_byte);
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      return c;
    }
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  if (CONSP (readcharfun))
    {
      /* This is the case that read_vector is reading from a unibyte
	 string that contains a byte sequence previously skipped
	 because of #@NUMBER.  The car part of readcharfun is that
	 string, and the cdr part is a value of readcharfun given to
	 read_vector.  */
      readbyte = readbyte_from_string;
      if (EQ (XCDR (readcharfun), Qget_emacs_mule_file_char))
	emacs_mule_encoding = 1;
      goto read_multibyte;
    }
  if (EQ (readcharfun, Qget_emacs_mule_file_char))
    {
      readbyte = readbyte_from_file;
      emacs_mule_encoding = 1;
      goto read_multibyte;
    }
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  tem = call0 (readcharfun);

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  if (NILP (tem))
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    return -1;
  return XINT (tem);
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 read_multibyte:
  if (unread_char >= 0)
    {
      c = unread_char;
      unread_char = -1;
      return c;
    }
  c = (*readbyte) (-1, readcharfun);
  if (c < 0 || ASCII_BYTE_P (c) || load_each_byte)
    return c;
  if (emacs_mule_encoding)
    return read_emacs_mule_char (c, readbyte, readcharfun);
  i = 0;
  buf[i++] = c;
  len = BYTES_BY_CHAR_HEAD (c);
  while (i < len)
    {
      c = (*readbyte) (-1, readcharfun);
      if (c < 0 || ! TRAILING_CODE_P (c))
	{
	  while (--i > 1)
	    (*readbyte) (buf[i], readcharfun);
	  return BYTE8_TO_CHAR (buf[0]);
	}
      buf[i++] = c;
    }
  return STRING_CHAR (buf, i);
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}

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/* Unread the character C in the way appropriate for the stream READCHARFUN.
   If the stream is a user function, call it with the char as argument.  */

static void
unreadchar (readcharfun, c)
     Lisp_Object readcharfun;
     int c;
{
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  if (c == -1)
    /* Don't back up the pointer if we're unreading the end-of-input mark,
       since readchar didn't advance it when we read it.  */
    ;
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  else if (BUFFERP (readcharfun))
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    {
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      struct buffer *b = XBUFFER (readcharfun);
      int bytepos = BUF_PT_BYTE (b);
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      BUF_PT (b)--;
      if (! NILP (b->enable_multibyte_characters))
	BUF_DEC_POS (b, bytepos);
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      else
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	bytepos--;
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      BUF_PT_BYTE (b) = bytepos;
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    }
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  else if (MARKERP (readcharfun))
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    {
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      struct buffer *b = XMARKER (readcharfun)->buffer;
      int bytepos = XMARKER (readcharfun)->bytepos;
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      XMARKER (readcharfun)->charpos--;
      if (! NILP (b->enable_multibyte_characters))
	BUF_DEC_POS (b, bytepos);
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      else
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	bytepos--;
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      XMARKER (readcharfun)->bytepos = bytepos;
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    }
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  else if (STRINGP (readcharfun))
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    {
      read_from_string_index--;
      read_from_string_index_byte
	= string_char_to_byte (readcharfun, read_from_string_index);
    }
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  else if (CONSP (readcharfun))
    {
      unread_char = c;
    }
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  else if (EQ (readcharfun, Qlambda))
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    {
      unread_char = c;
    }
  else if (EQ (readcharfun, Qget_file_char)
	   || EQ (readcharfun, Qget_emacs_mule_file_char))
    {
      if (load_each_byte)
	ungetc (c, instream);
      else
	unread_char = c;
    }
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  else
    call1 (readcharfun, make_number (c));
}

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static int
readbyte_for_lambda (c, readcharfun)
     int c;
     Lisp_Object readcharfun;
{
  return read_bytecode_char (c >= 0);
}


static int
readbyte_from_file (c, readcharfun)
     int c;
     Lisp_Object readcharfun;
{
  if (c >= 0)
    {
      ungetc (c, instream);
      return 0;
    }

  c = getc (instream);
#ifdef EINTR
  /* Interrupted reads have been observed while reading over the network */
  while (c == EOF && ferror (instream) && errno == EINTR)
    {
      clearerr (instream);
      c = getc (instream);
    }
#endif
  return (c == EOF ? -1 : c);
}

static int
readbyte_from_string (c, readcharfun)
     int c;
     Lisp_Object readcharfun;
{
  Lisp_Object string = XCAR (readcharfun);

  if (c >= 0)
    {
      read_from_string_index--;
      read_from_string_index_byte
	= string_char_to_byte (string, read_from_string_index);
    }
  
  if (read_from_string_index >= read_from_string_limit)
    c = -1;
  else
    FETCH_STRING_CHAR_ADVANCE (c, string,
			       read_from_string_index,
			       read_from_string_index_byte);
  return c;
}


/* Read one non-ASCII character from INSTREAM.  The character is
   encoded in `emacs-mule' and the first byte is already read in
   C.  */

extern char emacs_mule_bytes[256];

static int
read_emacs_mule_char (c, readbyte, readcharfun)
     int c;
     int (*readbyte) P_ ((int, Lisp_Object));
     Lisp_Object readcharfun;
{
  /* Emacs-mule coding uses at most 4-byte for one character.  */
  unsigned char buf[4];
  int len = emacs_mule_bytes[c];
  struct charset *charset;
  int i;
  unsigned code;

  if (len == 1)
    /* C is not a valid leading-code of `emacs-mule'.  */
    return BYTE8_TO_CHAR (c);

  i = 0;
  buf[i++] = c;
  while (i < len)
    {
      c = (*readbyte) (-1, readcharfun);
      if (c < 0xA0)
	{
	  while (--i > 1)
	    (*readbyte) (buf[i], readcharfun);
	  return BYTE8_TO_CHAR (buf[0]);
	}
      buf[i++] = c;
    }

  if (len == 2)
    {
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      charset = emacs_mule_charset[buf[0];
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      code = buf[1] & 0x7F;
    }
  else if (len == 3)
    {
      if (buf[0] == EMACS_MULE_LEADING_CODE_PRIVATE_11
	  || buf[0] == EMACS_MULE_LEADING_CODE_PRIVATE_12)
	{
	  charset = emacs_mule_charset[buf[1]];
	  code = buf[2] & 0x7F;
	}
      else
	{
	  charset = emacs_mule_charset[buf[0]];
	  code = ((buf[1] << 8) | buf[2]) & 0x7F7F;
	}
    }
  else
    {
      charset = emacs_mule_charset[buf[1]];
      code = ((buf[2] << 8) | buf[3]) & 0x7F7F;      
    }
  c = DECODE_CHAR (charset, code);
  if (c < 0)
    Fsignal (Qinvalid_read_syntax,
	     Fcons (build_string ("invalid multibyte form"), Qnil));
  return c;
}


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static Lisp_Object read0 (), read1 (), read_list (), read_vector ();
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static Lisp_Object substitute_object_recurse ();
static void        substitute_object_in_subtree (), substitute_in_interval ();

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/* Get a character from the tty.  */
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extern Lisp_Object read_char ();

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/* Read input events until we get one that's acceptable for our purposes.

   If NO_SWITCH_FRAME is non-zero, switch-frame events are stashed
   until we get a character we like, and then stuffed into
   unread_switch_frame.

   If ASCII_REQUIRED is non-zero, we check function key events to see
   if the unmodified version of the symbol has a Qascii_character
   property, and use that character, if present.

   If ERROR_NONASCII is non-zero, we signal an error if the input we
   get isn't an ASCII character with modifiers.  If it's zero but
   ASCII_REQUIRED is non-zero, we just re-read until we get an ASCII
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   character.

   If INPUT_METHOD is nonzero, we invoke the current input method
   if the character warrants that.  */
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Lisp_Object
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read_filtered_event (no_switch_frame, ascii_required, error_nonascii,
		     input_method)
     int no_switch_frame, ascii_required, error_nonascii, input_method;
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{
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  register Lisp_Object val, delayed_switch_frame;

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#ifdef HAVE_WINDOW_SYSTEM
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  if (display_hourglass_p)
    cancel_hourglass ();
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#endif
  
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  delayed_switch_frame = Qnil;
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  /* Read until we get an acceptable event.  */
 retry:
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  val = read_char (0, 0, 0,
		   (input_method ? Qnil : Qt),
		   0);
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  if (BUFFERP (val))
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    goto retry;

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  /* switch-frame events are put off until after the next ASCII
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     character.  This is better than signaling an error just because
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     the last characters were typed to a separate minibuffer frame,
     for example.  Eventually, some code which can deal with
     switch-frame events will read it and process it.  */
  if (no_switch_frame
      && EVENT_HAS_PARAMETERS (val)
      && EQ (EVENT_HEAD (val), Qswitch_frame))
    {
      delayed_switch_frame = val;
      goto retry;
    }

  if (ascii_required)
    {
      /* Convert certain symbols to their ASCII equivalents.  */
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      if (SYMBOLP (val))
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	{
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	  Lisp_Object tem, tem1;
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	  tem = Fget (val, Qevent_symbol_element_mask);
	  if (!NILP (tem))
	    {
	      tem1 = Fget (Fcar (tem), Qascii_character);
	      /* Merge this symbol's modifier bits
		 with the ASCII equivalent of its basic code.  */
	      if (!NILP (tem1))
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		XSETFASTINT (val, XINT (tem1) | XINT (Fcar (Fcdr (tem))));
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	    }
	}
	  
      /* If we don't have a character now, deal with it appropriately.  */
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      if (!INTEGERP (val))
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	{
	  if (error_nonascii)
	    {
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	      Vunread_command_events = Fcons (val, Qnil);
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	      error ("Non-character input-event");
	    }
	  else
	    goto retry;
	}
    }

  if (! NILP (delayed_switch_frame))
    unread_switch_frame = delayed_switch_frame;

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#ifdef HAVE_WINDOW_SYSTEM
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  if (display_hourglass_p)
    start_hourglass ();
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#endif
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  return val;
}

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DEFUN ("read-char", Fread_char, Sread_char, 0, 2, 0,
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       doc: /* Read a character from the command input (keyboard or macro).
It is returned as a number.
If the user generates an event which is not a character (i.e. a mouse
click or function key event), `read-char' signals an error.  As an
exception, switch-frame events are put off until non-ASCII events can
be read.
If you want to read non-character events, or ignore them, call
`read-event' or `read-char-exclusive' instead.

If the optional argument PROMPT is non-nil, display that as a prompt.
If the optional argument INHERIT-INPUT-METHOD is non-nil and some
input method is turned on in the current buffer, that input method
is used for reading a character.  */)
     (prompt, inherit_input_method)
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     Lisp_Object prompt, inherit_input_method;
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{
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  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
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  return read_filtered_event (1, 1, 1, ! NILP (inherit_input_method));
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}

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DEFUN ("read-event", Fread_event, Sread_event, 0, 2, 0,
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       doc: /* Read an event object from the input stream.
If the optional argument PROMPT is non-nil, display that as a prompt.
If the optional argument INHERIT-INPUT-METHOD is non-nil and some
input method is turned on in the current buffer, that input method
is used for reading a character.  */)
     (prompt, inherit_input_method)
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     Lisp_Object prompt, inherit_input_method;
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{
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  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
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  return read_filtered_event (0, 0, 0, ! NILP (inherit_input_method));
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}

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DEFUN ("read-char-exclusive", Fread_char_exclusive, Sread_char_exclusive, 0, 2, 0,
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       doc: /* Read a character from the command input (keyboard or macro).
It is returned as a number.  Non-character events are ignored.

If the optional argument PROMPT is non-nil, display that as a prompt.
If the optional argument INHERIT-INPUT-METHOD is non-nil and some
input method is turned on in the current buffer, that input method
is used for reading a character.  */)
     (prompt, inherit_input_method)
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     Lisp_Object prompt, inherit_input_method;
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{
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  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
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  return read_filtered_event (1, 1, 0, ! NILP (inherit_input_method));
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}

DEFUN ("get-file-char", Fget_file_char, Sget_file_char, 0, 0, 0,
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       doc: /* Don't use this yourself.  */)
     ()
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{
  register Lisp_Object val;
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  XSETINT (val, getc (instream));
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  return val;
}
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735

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/* Value is a version number of byte compiled code if the file
   associated with file descriptor FD is a compiled Lisp file that's
   safe to load.  Only files compiled with Emacs are safe to load.
   Files compiled with XEmacs can lead to a crash in Fbyte_code
   because of an incompatible change in the byte compiler.  */
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static int
safe_to_load_p (fd)
     int fd;
{
  char buf[512];
  int nbytes, i;
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  int safe_p = 1, version = 0;
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  /* Read the first few bytes from the file, and look for a line
     specifying the byte compiler version used.  */
  nbytes = emacs_read (fd, buf, sizeof buf - 1);
  if (nbytes > 0)
    {
      buf[nbytes] = '\0';

      /* Skip to the next newline, skipping over the initial `ELC'
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	 with NUL bytes following it, but note the version.  */
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      for (i = 0; i < nbytes && buf[i] != '\n'; ++i)
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	if (i == 4)
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	  version = buf[i];
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      if (i == nbytes
	  || fast_c_string_match_ignore_case (Vbytecomp_version_regexp,
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					      buf + i) < 0)
	safe_p = 0;
    }
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  if (safe_p)
    safe_p = version;
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  lseek (fd, 0, SEEK_SET);
  return safe_p;
}


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/* Callback for record_unwind_protect.  Restore the old load list OLD,
   after loading a file successfully.  */

static Lisp_Object
record_load_unwind (old)
     Lisp_Object old;
{
  return Vloads_in_progress = old;
}


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DEFUN ("load", Fload, Sload, 1, 5, 0,
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       doc: /* Execute a file of Lisp code named FILE.
First try FILE with `.elc' appended, then try with `.el',
 then try FILE unmodified.  Environment variable references in FILE
 are replaced with their values by calling `substitute-in-file-name'.
This function searches the directories in `load-path'.
If optional second arg NOERROR is non-nil,
 report no error if FILE doesn't exist.
Print messages at start and end of loading unless
 optional third arg NOMESSAGE is non-nil.
If optional fourth arg NOSUFFIX is non-nil, don't try adding
 suffixes `.elc' or `.el' to the specified name FILE.
If optional fifth arg MUST-SUFFIX is non-nil, insist on
 the suffix `.elc' or `.el'; don't accept just FILE unless
 it ends in one of those suffixes or includes a directory name.
Return t if file exists.  */)
     (file, noerror, nomessage, nosuffix, must_suffix)
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     Lisp_Object file, noerror, nomessage, nosuffix, must_suffix;
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{
  register FILE *stream;
  register int fd = -1;
  register Lisp_Object lispstream;
  int count = specpdl_ptr - specpdl;
  Lisp_Object temp;
  struct gcpro gcpro1;
  Lisp_Object found;
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  /* 1 means we printed the ".el is newer" message.  */
  int newer = 0;
  /* 1 means we are loading a compiled file.  */
  int compiled = 0;
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  Lisp_Object handler;
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  int safe_p = 1;
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  char *fmode = "r";
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  int version;

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#ifdef DOS_NT
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  fmode = "rt";
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#endif /* DOS_NT */
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  CHECK_STRING (file);
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  /* If file name is magic, call the handler.  */
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  /* This shouldn't be necessary any more now that `openp' handles it right.
    handler = Ffind_file_name_handler (file, Qload);
    if (!NILP (handler))
      return call5 (handler, Qload, file, noerror, nomessage, nosuffix); */
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  /* Do this after the handler to avoid
     the need to gcpro noerror, nomessage and nosuffix.
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     (Below here, we care only whether they are nil or not.)
     The presence of this call is the result of a historical accident:
     it used to be in every file-operations and when it got removed
     everywhere, it accidentally stayed here.  Since then, enough people
     supposedly have things like (load "$PROJECT/foo.el") in their .emacs
     that it seemed risky to remove.  */
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  file = Fsubstitute_in_file_name (file);
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  /* Avoid weird lossage with null string as arg,
     since it would try to load a directory as a Lisp file */
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  if (XSTRING (file)->size > 0)
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    {
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      int size = STRING_BYTES (XSTRING (file));
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      Lisp_Object tmp[2];
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      GCPRO1 (file);
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      if (! NILP (must_suffix))
	{
	  /* Don't insist on adding a suffix if FILE already ends with one.  */
	  if (size > 3
	      && !strcmp (XSTRING (file)->data + size - 3, ".el"))
	    must_suffix = Qnil;
	  else if (size > 4
		   && !strcmp (XSTRING (file)->data + size - 4, ".elc"))
	    must_suffix = Qnil;
	  /* Don't insist on adding a suffix
	     if the argument includes a directory name.  */
	  else if (! NILP (Ffile_name_directory (file)))
	    must_suffix = Qnil;
	}

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      fd = openp (Vload_path, file,
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		  (!NILP (nosuffix) ? Qnil
		   : !NILP (must_suffix) ? Vload_suffixes
		   : Fappend (2, (tmp[0] = Vload_suffixes,
				  tmp[1] = default_suffixes,
				  tmp))),
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		  &found, 0);
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      UNGCPRO;
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    }

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  if (fd == -1)
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    {
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      if (NILP (noerror))
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	while (1)
	  Fsignal (Qfile_error, Fcons (build_string ("Cannot open load file"),
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				       Fcons (file, Qnil)));
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      else
	return Qnil;
    }

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  /* Tell startup.el whether or not we found the user's init file.  */
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  if (EQ (Qt, Vuser_init_file))
    Vuser_init_file = found;

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  /* If FD is -2, that means openp found a magic file.  */
  if (fd == -2)
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    {
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      if (NILP (Fequal (found, file)))
	/* If FOUND is a different file name from FILE,
	   find its handler even if we have already inhibited
	   the `load' operation on FILE.  */
	handler = Ffind_file_name_handler (found, Qt);
      else
	handler = Ffind_file_name_handler (found, Qload);
      if (! NILP (handler))
	return call5 (handler, Qload, found, noerror, nomessage, Qt);
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    }

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  /* Check if we're stuck in a recursive load cycle.

     2000-09-21: It's not possible to just check for the file loaded
     being a member of Vloads_in_progress.  This fails because of the
     way the byte compiler currently works; `provide's are not
     evaluted, see font-lock.el/jit-lock.el as an example.  This
     leads to a certain amount of ``normal'' recursion.

     Also, just loading a file recursively is not always an error in
     the general case; the second load may do something different.  */
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  {
    int count = 0;
    Lisp_Object tem;
    for (tem = Vloads_in_progress; CONSP (tem); tem = XCDR (tem))
      if (!NILP (Fequal (found, XCAR (tem))))
	count++;
    if (count > 3)
      Fsignal (Qerror, Fcons (build_string ("Recursive load"),
			      Fcons (found, Vloads_in_progress)));
    record_unwind_protect (record_load_unwind, Vloads_in_progress);
    Vloads_in_progress = Fcons (found, Vloads_in_progress);
  }
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  version = -1;
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  if (!bcmp (&(XSTRING (found)->data[STRING_BYTES (XSTRING (found)) - 4]),
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	     ".elc", 4)
      || (version = safe_to_load_p (fd)) > 0)
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    /* Load .elc files directly, but not when they are
       remote and have no handler!  */
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    {
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      if (fd != -2)
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	{
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	  struct stat s1, s2;
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	  int result;
940

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	  if (version < 0
	      && ! (version = safe_to_load_p (fd)))
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	    {
	      safe_p = 0;
	      if (!load_dangerous_libraries)
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		{
		  emacs_close (fd);
		  error ("File `%s' was not compiled in Emacs",
			 XSTRING (found)->data);
		}
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	      else if (!NILP (nomessage))
		message_with_string ("File `%s' not compiled in Emacs", found, 1);
	    }
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	  compiled = 1;

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#ifdef DOS_NT
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	  fmode = "rb";
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#endif /* DOS_NT */
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	  stat ((char *)XSTRING (found)->data, &s1);
	  XSTRING (found)->data[STRING_BYTES (XSTRING (found)) - 1] = 0;
	  result = stat ((char *)XSTRING (found)->data, &s2);
	  if (result >= 0 && (unsigned) s1.st_mtime < (unsigned) s2.st_mtime)
	    {
	      /* Make the progress messages mention that source is newer.  */
	      newer = 1;
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	      /* If we won't print another message, mention this anyway.  */
	      if (! NILP (nomessage))
		message_with_string ("Source file `%s' newer than byte-compiled file",
				     found, 1);
	    }
	  XSTRING (found)->data[STRING_BYTES (XSTRING (found)) - 1] = 'c';
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	}
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    }
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  else
    {
      /* We are loading a source file (*.el).  */
      if (!NILP (Vload_source_file_function))
	{
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	  Lisp_Object val;
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	  if (fd >= 0)
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	    emacs_close (fd);
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	  val = call4 (Vload_source_file_function, found, file,
		       NILP (noerror) ? Qnil : Qt,
		       NILP (nomessage) ? Qnil : Qt);
	  return unbind_to (count, val);
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	}
    }
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#ifdef WINDOWSNT
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  emacs_close (fd);
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  stream = fopen ((char *) XSTRING (found)->data, fmode);
#else  /* not WINDOWSNT */
  stream = fdopen (fd, fmode);
#endif /* not WINDOWSNT */
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  if (stream == 0)
    {
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      emacs_close (fd);
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      error ("Failure to create stdio stream for %s", XSTRING (file)->data);
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    }

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  if (! NILP (Vpurify_flag))
    Vpreloaded_file_list = Fcons (file, Vpreloaded_file_list);

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  if (NILP (nomessage))
    {
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      if (!safe_p)
	message_with_string ("Loading %s (compiled; note unsafe, not compiled in Emacs)...",
		 file, 1);
      else if (!compiled)
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	message_with_string ("Loading %s (source)...", file, 1);
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      else if (newer)
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	message_with_string ("Loading %s (compiled; note, source file is newer)...",
		 file, 1);
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      else /* The typical case; compiled file newer than source file.  */
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	message_with_string ("Loading %s...", file, 1);
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    }
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  GCPRO1 (file);
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  lispstream = Fcons (Qnil, Qnil);
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  XSETCARFASTINT (lispstream, (EMACS_UINT)stream >> 16);
  XSETCDRFASTINT (lispstream, (EMACS_UINT)stream & 0xffff);
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  record_unwind_protect (load_unwind, lispstream);
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  record_unwind_protect (load_descriptor_unwind, load_descriptor_list);
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  specbind (Qload_file_name, found);
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  specbind (Qinhibit_file_name_operation, Qnil);
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  load_descriptor_list
    = Fcons (make_number (fileno (stream)), load_descriptor_list);
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  load_in_progress++;
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  if (! version || version >= 22)
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    readevalloop (Qget_file_char, stream, file, Feval, 0, Qnil, Qnil);
  else
    {
      /* We can't handle a file which was compiled with
	 byte-compile-dynamic by older version of Emacs.  */
      specbind (Qload_force_doc_strings, Qt);
      readevalloop (Qget_emacs_mule_file_char, stream, file, Feval, 0,
		    Qnil, Qnil);
    }
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  unbind_to (count, Qnil);

  /* Run any load-hooks for this file.  */
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  temp = Fassoc (file, Vafter_load_alist);
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  if (!NILP (temp))
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    Fprogn (Fcdr (temp));
  UNGCPRO;

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  if (saved_doc_string)
    free (saved_doc_string);
  saved_doc_string = 0;
  saved_doc_string_size = 0;

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  if (prev_saved_doc_string)
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    xfree (prev_saved_doc_string);
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  prev_saved_doc_string = 0;
  prev_saved_doc_string_size = 0;

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  if (!noninteractive && NILP (nomessage))
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    {
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      if (!safe_p)
	message_with_string ("Loading %s (compiled; note unsafe, not compiled in Emacs)...done",
		 file, 1);
      else if (!compiled)
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	message_with_string ("Loading %s (source)...done", file, 1);
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      else if (newer)
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	message_with_string ("Loading %s (compiled; note, source file is newer)...done",
		 file, 1);
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      else /* The typical case; compiled file newer than source file.  */
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	message_with_string ("Loading %s...done", file, 1);