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1 | ;;; -*-lisp-*- |
2 | ;;; | |
3 | ;;; Code generation protocol implementation | |
4 | ;;; | |
5 | ;;; (c) 2009 Straylight/Edgeware | |
6 | ;;; | |
7 | ||
8 | ;;;----- Licensing notice --------------------------------------------------- | |
9 | ;;; | |
e0808c47 | 10 | ;;; This file is part of the Sensible Object Design, an object system for C. |
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11 | ;;; |
12 | ;;; SOD is free software; you can redistribute it and/or modify | |
13 | ;;; it under the terms of the GNU General Public License as published by | |
14 | ;;; the Free Software Foundation; either version 2 of the License, or | |
15 | ;;; (at your option) any later version. | |
16 | ;;; | |
17 | ;;; SOD is distributed in the hope that it will be useful, | |
18 | ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | ;;; GNU General Public License for more details. | |
21 | ;;; | |
22 | ;;; You should have received a copy of the GNU General Public License | |
23 | ;;; along with SOD; if not, write to the Free Software Foundation, | |
24 | ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
25 | ||
26 | (cl:in-package #:sod) | |
27 | ||
28 | ;;;-------------------------------------------------------------------------- | |
29 | ;;; Temporary names. | |
30 | ||
31 | (export '(temporary-argument temporary-function)) | |
32 | (defclass temporary-argument (temporary-name) ()) | |
33 | (defclass temporary-function (temporary-name) ()) | |
34 | ||
35 | (export 'temporary-variable) | |
36 | (defclass temporary-variable (temporary-name) | |
37 | ((in-use-p :initarg :in-use-p :initform nil | |
38 | :type boolean :accessor var-in-use-p))) | |
39 | ||
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40 | (define-module-var *temporary-index* 0 |
41 | "Index for temporary name generation. | |
42 | ||
43 | This is automatically reset to zero before the output functions are | |
44 | invoked to write a file. This way, we can ensure that the same output | |
45 | file is always produced from the same input.") | |
46 | ||
47 | (define-clear-the-decks reset-codegen-index | |
48 | (setf *temporary-index* 0)) | |
49 | ||
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50 | (defmethod commentify-argument-name ((name temporary-name)) |
51 | nil) | |
52 | ||
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53 | (defun temporary-function () |
54 | "Return a temporary function name." | |
55 | (make-instance 'temporary-function | |
56 | :tag (prog1 *temporary-index* (incf *temporary-index*)))) | |
57 | ||
58 | (defmethod format-temporary-name ((var temporary-name) stream) | |
59 | (format stream "~A" (temp-tag var))) | |
60 | (defmethod format-temporary-name ((var temporary-argument) stream) | |
61 | (format stream "sod__a~A" (temp-tag var))) | |
62 | (defmethod format-temporary-name ((var temporary-variable) stream) | |
63 | (format stream "sod__v~A" (temp-tag var))) | |
64 | (defmethod format-temporary-name ((var temporary-function) stream) | |
65 | (format stream "sod__f~A" (temp-tag var))) | |
66 | ||
67 | (defmethod print-object ((var temporary-name) stream) | |
68 | (if *print-escape* | |
69 | (print-unreadable-object (var stream :type t) | |
70 | (prin1 (temp-tag var) stream)) | |
71 | (format-temporary-name var stream))) | |
72 | ||
73 | ;;;-------------------------------------------------------------------------- | |
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74 | ;;; Code generator objects. |
75 | ||
76 | (defclass basic-codegen () | |
77 | ((vars :initarg :vars :initform nil :type list :accessor codegen-vars) | |
78 | (insts :initarg :insts :initform nil :type list :accessor codegen-insts) | |
79 | (temp-index :initarg :temp-index :initform 0 | |
80 | :type fixnum :accessor codegen-temp-index)) | |
81 | (:documentation | |
82 | "Base class for code generator state. | |
83 | ||
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84 | This contains the bare essentials for supporting the `emit-inst' and |
85 | `ensure-var' protocols; see the documentation for those generic functions | |
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86 | for more details. |
87 | ||
3109662a | 88 | This class isn't abstract. A full `codegen' object uses instances of this |
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89 | to keep track of pending functions which haven't been completed yet. |
90 | ||
91 | Just in case that wasn't clear enough: this is nothing to do with the | |
92 | BASIC language.")) | |
93 | ||
94 | (defmethod emit-inst ((codegen basic-codegen) inst) | |
95 | (push inst (codegen-insts codegen))) | |
96 | ||
97 | (defmethod emit-insts ((codegen basic-codegen) insts) | |
98 | (asetf (codegen-insts codegen) (revappend insts it))) | |
99 | ||
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100 | (defmethod emit-decl ((codegen basic-codegen) inst) |
101 | (push inst (codegen-vars codegen))) | |
102 | ||
103 | (defmethod emit-decls ((codegen basic-codegen) insts) | |
104 | (asetf (codegen-vars codegen) (revappend insts it))) | |
105 | ||
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106 | (defmethod ensure-var ((codegen basic-codegen) name type &optional init) |
107 | (let* ((vars (codegen-vars codegen)) | |
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108 | (var (find name |
109 | (remove-if-not (lambda (var) (typep var 'var-inst)) vars) | |
110 | :key #'inst-name :test #'equal))) | |
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111 | (cond ((not var) |
112 | (setf (codegen-vars codegen) | |
113 | (cons (make-var-inst name type init) vars))) | |
114 | ((not (c-type-equal-p type (inst-type var))) | |
a1985b3c | 115 | (error "(Internal) Redefining type for variable ~A" name))) |
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116 | name)) |
117 | ||
118 | (export 'codegen) | |
119 | (defclass codegen (basic-codegen) | |
120 | ((functions :initform nil :type list :accessor codegen-functions) | |
121 | (stack :initform nil :type list :accessor codegen-stack)) | |
122 | (:documentation | |
123 | "A full-fat code generator which can generate and track functions. | |
124 | ||
125 | This is the real deal. Subclasses may which to attach additional state | |
126 | for convenience's sake, but this class is self-contained. It supports the | |
3109662a | 127 | `codegen-push', `codegen-pop' and `codegen-pop-function' protocols.")) |
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128 | |
129 | (defmethod codegen-push ((codegen codegen)) | |
130 | (with-slots (vars insts temp-index stack) codegen | |
131 | (push (make-instance 'basic-codegen | |
132 | :vars vars | |
133 | :insts insts | |
134 | :temp-index temp-index) | |
135 | stack) | |
136 | (setf vars nil insts nil temp-index 0))) | |
137 | ||
138 | (defmethod codegen-pop ((codegen codegen)) | |
139 | (with-slots (vars insts temp-index stack) codegen | |
140 | (multiple-value-prog1 | |
141 | (values (nreverse vars) (nreverse insts)) | |
142 | (let ((sub (pop stack))) | |
143 | (setf vars (codegen-vars sub) | |
144 | insts (codegen-insts sub) | |
145 | temp-index (codegen-temp-index sub)))))) | |
146 | ||
147 | (defmethod codegen-add-function ((codegen codegen) function) | |
148 | (with-slots (functions) codegen | |
149 | (setf functions (nconc functions (list function))))) | |
150 | ||
151 | (defmethod temporary-var ((codegen basic-codegen) type) | |
152 | (with-slots (vars temp-index) codegen | |
153 | (or (some (lambda (var) | |
154 | (let ((name (inst-name var))) | |
155 | (if (and (not (var-in-use-p name)) | |
156 | (c-type-equal-p type (inst-type var))) | |
157 | name | |
158 | nil))) | |
66836e14 | 159 | (remove-if-not (lambda (var) (typep var 'var-inst)) vars)) |
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160 | (let* ((name (make-instance 'temporary-variable |
161 | :in-use-p t | |
162 | :tag (prog1 temp-index | |
163 | (incf temp-index))))) | |
167524b5 | 164 | (push (make-var-inst name type) vars) |
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165 | name)))) |
166 | ||
167 | ;;;----- That's all, folks -------------------------------------------------- |