1 ;;;; DEFMACRO machinery
3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This software is derived from the CMU CL system, which was
7 ;;;; written at Carnegie Mellon University and released into the
8 ;;;; public domain. The software is in the public domain and is
9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
10 ;;;; files for more information.
12 (in-package "SB!IMPL")
17 ;;; the guts of the DEFMACRO macro, pulled out into a separate
18 ;;; function in order to make it easier to express the common
20 ;;; CL:DEFMACRO SB!XC:DEFMACRO
21 ;;; SB!XC:DEFMACRO CL:DEFMACRO
22 (eval-when (:compile-toplevel :load-toplevel :execute)
23 (defun %expander-for-defmacro (name lambda-list body)
24 (let ((whole (gensym "WHOLE-"))
25 (environment (gensym "ENV-")))
26 (multiple-value-bind (new-body local-decs doc)
27 (parse-defmacro lambda-list whole body name 'defmacro
28 :environment environment)
29 (let ((def `(lambda (,whole ,environment)
33 `(sb!c::%defmacro ',name #',def ',lambda-list ,doc))))))
35 ;;; Ordinarily this definition of SB!C:%DEFMACRO as an ordinary
36 ;;; function is not used: the parallel (but different) definition as
37 ;;; an IR1 transform takes precedence. However, this definition is
38 ;;; still useful in the target interpreter, and in the
39 ;;; cross-compilation host.
40 (defun sb!c::%defmacro (name definition lambda-list doc)
41 (try-to-rename-interpreted-function-as-macro definition name lambda-list)
42 (sb!c::%%defmacro name definition doc))
44 ;;; (called by SB!C::%DEFMACRO)
45 (eval-when (:compile-toplevel :load-toplevel :execute)
46 (defun sb!c::%%defmacro (name definition doc)
47 ;; Old note (ca. 1985, maybe:-): "Eventually %%DEFMACRO should deal with
48 ;; clearing old compiler information for the functional value."
49 (clear-info :function :where-from name)
50 ;; FIXME: It would be nice to warn about DEFMACRO of an
51 ;; already-defined macro, but that's slightly hard to do because
52 ;; in common usage DEFMACRO is defined at compile time and then
53 ;; redefined at load time. We'd need to make a distinction between
54 ;; the defined-at-compile-time state and the defined-at-load-time
55 ;; state to make this work. (Trying to warn about duplicate DEFTYPEs
56 ;; runs into the same problem.)
57 #+nil (when (sb!xc:macro-function name)
58 (style-warn "redefining ~S in DEFMACRO" name))
59 (setf (sb!xc:macro-function name) definition
60 (fdocumentation name 'function) doc)
63 ;;; Parse the definition and make an expander function. The actual
64 ;;; definition is done by %DEFMACRO which we expand into, and which is
65 ;;; handled magically by an IR1 transform. After the compiler has
66 ;;; gotten the information it wants out of macro definition, it
67 ;;; compiles a call to %%DEFMACRO which happens at load time.
68 (defmacro sb!xc:defmacro (name lambda-list &rest body)
69 (%expander-for-defmacro name lambda-list body))
71 ;;; In the cross-compiler, we not only need to support the definition
72 ;;; of target macros at cross-compiler-build-time (with SB!XC:DEFMACRO
73 ;;; running in the cross-compilation host), we also need to support
74 ;;; the definition of target macros at target compilation time (with
75 ;;; CL:DEFMACRO processed by the cross-compiler)..
77 (sb!xc:defmacro defmacro (name lambda-list &rest body)
78 (%expander-for-defmacro name lambda-list body))
80 ;;; DEFMACRO-MUNDANELY is like SB!XC:DEFMACRO, except that it doesn't
81 ;;; have any EVAL-WHEN or IR1 magic associated with it, so it only
82 ;;; takes effect in :LOAD-TOPLEVEL or :EXECUTE situations.
84 ;;; KLUDGE: Currently this is only used for various special
85 ;;; circumstances in bootstrapping, but it seems to me that it might
86 ;;; be a good basis for reimplementation of DEFMACRO in terms of
87 ;;; EVAL-WHEN, which might be easier to understand than the current
88 ;;; approach based on IR1 magic. -- WHN 19990811
89 (def!macro defmacro-mundanely (name lambda-list &body body)
90 `(setf (sb!xc:macro-function ',name)
91 ,(let ((whole (gensym "WHOLE-"))
92 (environment (gensym "ENVIRONMENT-")))
93 (multiple-value-bind (new-body local-decs doc)
94 (parse-defmacro lambda-list whole body name 'defmacro
95 :environment environment)
96 (declare (ignore doc))
97 `(lambda (,whole ,environment)