view src/opaque.h @ 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
line source

/* Opaque Lisp objects.
   Copyright (C) 1993 Sun Microsystems, Inc.
   Copyright (C) 1995, 1996 Ben Wing.

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/>. */

/* Synched up with: Not in FSF. */

/* Written by Ben Wing, October 1993. */

#ifndef INCLUDED_opaque_h_
#define INCLUDED_opaque_h_

typedef struct Lisp_Opaque
{
  NORMAL_LISP_OBJECT_HEADER header;
  Bytecount size;
  max_align_t data[1];
} Lisp_Opaque;

DECLARE_LISP_OBJECT (opaque, Lisp_Opaque);
#define XOPAQUE(x) XRECORD (x, opaque, Lisp_Opaque)
#define wrap_opaque(p) wrap_record (p, opaque)
#define OPAQUEP(x) RECORDP (x, opaque)
/* #define CHECK_OPAQUE(x) CHECK_RECORD (x, opaque)
   Opaque pointers should never escape to the Lisp level, so
   functions should not be doing this. */

/* Alternative DATA arguments to make_opaque() */
#define OPAQUE_CLEAR  ((const void *)  0)
#define OPAQUE_UNINIT ((const void *) -1)

#define OPAQUE_SIZE(op) ((op)->size)
#define OPAQUE_DATA(op) ((void *) ((op)->data))
#define XOPAQUE_SIZE(op) OPAQUE_SIZE (XOPAQUE (op))
#define XOPAQUE_DATA(op) OPAQUE_DATA (XOPAQUE (op))

Lisp_Object make_opaque (const void *data, Bytecount size);

typedef struct Lisp_Opaque_Ptr
{
  NORMAL_LISP_OBJECT_HEADER header;
  void *ptr;
} Lisp_Opaque_Ptr;

DECLARE_LISP_OBJECT (opaque_ptr, Lisp_Opaque_Ptr);
#define XOPAQUE_PTR(x) XRECORD (x, opaque_ptr, Lisp_Opaque_Ptr)
#define wrap_opaque_ptr(p) wrap_record (p, opaque_ptr)
#define OPAQUE_PTRP(x) RECORDP (x, opaque_ptr)

EXTERN_C MODULE_API Lisp_Object make_opaque_ptr (void *val);
EXTERN_C MODULE_API void free_opaque_ptr (Lisp_Object ptr);

#define get_opaque_ptr(op) (XOPAQUE_PTR (op)->ptr)
#define set_opaque_ptr(op, ptr_) (XOPAQUE_PTR (op)->ptr = (ptr_))

#endif /* INCLUDED_opaque_h_ */