view lib-src/make-dump-id.c @ 5566:4654c01af32b

Improve the implementation, documentation of #'labels, #'flet. lisp/ChangeLog addition: 2011-09-07 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el: * bytecomp.el (for-effect): Move this earlier in the file, it's referenced in byte-compile-initial-macro-environment. * bytecomp.el (byte-compile-initial-macro-environment): In the byte-compile-macro-environment definition for #'labels, put off the compiling the lambda bodies until the point where the rest of the form is being compiled, allowing the lambda bodies to access appropriate values for byte-compile-bound-variables, and reducing excessive warning about free variables. Add a byte-compile-macro-environment definition for #'flet. This modifies byte-compile-function-environment appropriately, and warns about bindings of functions that have macro definitions in the current environment, about functions that have byte codes, and about functions that have byte-compile methods (which may not do what the user wants at runtime). * bytecomp.el (byte-compile-funcall): If FUNCTION is constant, call #'byte-compile-callargs-warn if that's appropriate, giving warnings about problems with calling functions bound with #'labels. * cl-macs.el: * cl-macs.el (flet): Mention the main difference from Common Lisp, that the bindings are dynamic, not lexical. Counsel the use of #'labels, not #'flet, for this and other reasons. Explain the limited single use case for #'flet. Cross-reference to bytecomp.el in a comment. * cl-macs.el (labels): Go into detail on which functions may be called from where. Explain how to access the function definition of a label within FORM. Add a comment cross-referencing to bytecomp.el. man/ChangeLog addition: 2011-09-07 Aidan Kehoe <kehoea@parhasard.net> * cl.texi (Function Bindings): Move #'labels first, describe it in more detail, explaining that it is to be preferred over #'flet, and explaining why. Explain that dynamic bindings with #'flet will also not work when functions are accessed through their bytecodes.
author Aidan Kehoe <kehoea@parhasard.net>
date Wed, 07 Sep 2011 16:26:45 +0100
parents 308d34e9f07d
children
line wrap: on
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/* Generate a unique dump-id for use with the portable dumper.
   Copyright (C) 2000 Olivier Galibert, Martin Buchholz

This file is part of XEmacs.

XEmacs 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.

XEmacs 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 XEmacs.  If not, see <http://www.gnu.org/licenses/>. */

#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include "../src/systime.h"

#ifdef WIN32_NATIVE
#include <sys/timeb.h>

/* Emulate gettimeofday (Ulrich Leodolter, 1/11/95).  */
void 
gettimeofday (struct timeval *tv, struct timezone *tz)
{
  struct _timeb tb;
  _ftime (&tb);

  tv->tv_sec = tb.time;
  tv->tv_usec = tb.millitm * 1000L;
  if (tz) 
    {
      tz->tz_minuteswest = tb.timezone;	/* minutes west of Greenwich  */
      tz->tz_dsttime = tb.dstflag;	/* type of dst correction  */
    }
}
#endif

/* Generates an (extremely) pseudo random number for the dump-id */
static unsigned int
generate_dump_id (void)
{
  EMACS_TIME thyme;
  EMACS_GET_TIME (thyme);

  return (unsigned int) (EMACS_SECS (thyme) ^ EMACS_USECS (thyme));
}

int
main (int argc, char **argv)
{
  FILE *f;

  if ((f = fopen ("dump-id.c", "w")) == NULL)
    {
      perror ("open dump-id.c");
      return EXIT_FAILURE;
    }

  /* dump_id is declared as extern "C" in dumper.h */
  fputs ("extern\n", f);
  fputs ("#ifdef __cplusplus\n", f);
  fputs ("\"C\"\n", f);
  fputs ("#endif\n", f);
  fputs ("unsigned int dump_id;\n", f);
  fprintf (f, "unsigned int dump_id = %uU;\n", generate_dump_id ());

  if ((fclose (f)) != 0)
    {
      perror ("close dump-id.c");
      return EXIT_FAILURE;
    }

  return EXIT_SUCCESS;
}