1 | /* Bison code properties structure and scanner. |
2 | |
3 | Copyright (C) 2006-2007, 2009-2015, 2018-2019 Free Software |
4 | Foundation, Inc. |
5 | |
6 | This file is part of Bison, the GNU Compiler Compiler. |
7 | |
8 | This program is free software: you can redistribute it and/or modify |
9 | it under the terms of the GNU General Public License as published by |
10 | the Free Software Foundation, either version 3 of the License, or |
11 | (at your option) any later version. |
12 | |
13 | This program is distributed in the hope that it will be useful, |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
16 | GNU General Public License for more details. |
17 | |
18 | You should have received a copy of the GNU General Public License |
19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
20 | |
21 | #ifndef SCAN_CODE_H_ |
22 | # define SCAN_CODE_H_ |
23 | |
24 | # include "location.h" |
25 | # include "named-ref.h" |
26 | # include "uniqstr.h" |
27 | |
28 | struct symbol_list; |
29 | |
30 | /** |
31 | * Keeps track of the maximum number of semantic values to the left of a handle |
32 | * (those referenced by $0, $-1, etc.) that are required by the semantic |
33 | * actions of this grammar. |
34 | */ |
35 | extern int max_left_semantic_context; |
36 | |
37 | /** |
38 | * A code passage captured from the grammar file and possibly translated, |
39 | * and/or properties associated with such a code passage. Don't break |
40 | * encapsulation by modifying the fields directly. Use the provided interface |
41 | * functions. |
42 | */ |
43 | typedef struct code_props { |
44 | /** Set by the init functions. */ |
45 | enum { |
46 | CODE_PROPS_NONE, CODE_PROPS_PLAIN, |
47 | CODE_PROPS_SYMBOL_ACTION, CODE_PROPS_RULE_ACTION |
48 | } kind; |
49 | |
50 | /** |
51 | * \c NULL iff \c code_props::kind is \c CODE_PROPS_NONE. |
52 | * Memory is allocated in an obstack freed elsewhere. |
53 | */ |
54 | char const *code; |
55 | /** Undefined iff \c code_props::code is \c NULL. */ |
56 | location location; |
57 | |
58 | /** |
59 | * \c false iff either: |
60 | * - \c code_props_translate_code has never previously been invoked for |
61 | * the \c code_props that would contain the code passage associated |
62 | * with \c self. (That \c code_props is not the same as this one if this |
63 | * one is for a RHS \c symbol_list node. Instead, it's the \c code_props |
64 | * for the LHS symbol of the same rule.) |
65 | * - \c code_props_translate_code has been invoked for that \c code_props, |
66 | * but the symbol value associated with this \c code_props was not |
67 | * referenced in the code passage. |
68 | */ |
69 | bool is_value_used; |
70 | |
71 | /** |
72 | * \c true iff this code is an action that is not to be deferred in |
73 | * a non-deterministic parser. |
74 | */ |
75 | bool is_predicate; |
76 | |
77 | /** |
78 | * Whether this is actually used (i.e., not completely masked by |
79 | * other code props). */ |
80 | bool is_used; |
81 | |
82 | /** \c NULL iff \c code_props::kind is not \c CODE_PROPS_RULE_ACTION. */ |
83 | struct symbol_list *rule; |
84 | |
85 | /** Named reference. */ |
86 | named_ref *named_ref; |
87 | |
88 | /** Type, for midrule actions. */ |
89 | uniqstr type; |
90 | } code_props; |
91 | |
92 | /** |
93 | * \pre |
94 | * - <tt>self != NULL</tt>. |
95 | * \post |
96 | * - \c self has been overwritten to contain no code. |
97 | */ |
98 | void code_props_none_init (code_props *self); |
99 | |
100 | /** Equivalent to \c code_props_none_init. */ |
101 | # define CODE_PROPS_NONE_INIT \ |
102 | { \ |
103 | /* .kind = */ CODE_PROPS_NONE, \ |
104 | /* .code = */ NULL, \ |
105 | /* .location = */ EMPTY_LOCATION_INIT, \ |
106 | /* .is_value_used = */ false, \ |
107 | /* .is_predicate = */ false, \ |
108 | /* .is_used = */ false, \ |
109 | /* .rule = */ NULL, \ |
110 | /* .named_ref = */ NULL, \ |
111 | /* .type = */ NULL, \ |
112 | } |
113 | |
114 | /** Initialized by \c CODE_PROPS_NONE_INIT with no further modification. */ |
115 | extern code_props code_props_none; |
116 | |
117 | /** |
118 | * \pre |
119 | * - <tt>self != NULL</tt>. |
120 | * - <tt>code != NULL</tt>. |
121 | * - \c code is an untranslated code passage containing no Bison escapes. |
122 | * - \c code was extracted from the grammar file at \c code_loc. |
123 | * \post |
124 | * - \c self has been overwritten to represent the specified plain code |
125 | * passage. |
126 | * - \c self will become invalid if the caller frees \c code before invoking |
127 | * \c code_props_translate_code on \c self. |
128 | */ |
129 | void code_props_plain_init (code_props *self, char const *code, |
130 | location code_loc); |
131 | |
132 | /** |
133 | * \pre |
134 | * - <tt>self != NULL</tt>. |
135 | * - <tt>code != NULL</tt>. |
136 | * - \c code is an untranslated code passage. The only Bison escapes it |
137 | * might contain are $$ and \@$, referring to a single symbol. |
138 | * - \c code was extracted from the grammar file at \c code_loc. |
139 | * \post |
140 | * - \c self has been overwritten to represent the specified symbol action. |
141 | * - \c self will become invalid if the caller frees \c code before invoking |
142 | * \c code_props_translate_code on \c self. |
143 | */ |
144 | void code_props_symbol_action_init (code_props *self, char const *code, |
145 | location code_loc); |
146 | |
147 | /** |
148 | * \pre |
149 | * - <tt>self != NULL</tt>. |
150 | * - <tt>code != NULL</tt>. |
151 | * - <tt>rule != NULL</tt>. |
152 | * - \c code is the untranslated action of the rule for which \c rule is the |
153 | * LHS node. Thus, \c code possibly contains Bison escapes such as $$, $1, |
154 | * $2, etc referring to the values of the rule. |
155 | * - \c code was extracted from the grammar file at \c code_loc. |
156 | * \post |
157 | * - \c self has been overwritten to represent the specified rule action. |
158 | * - \c self does not claim responsibility for the memory of \c rule. |
159 | * - \c self will become invalid if: |
160 | * - The caller frees \c code before invoking \c code_props_translate_code |
161 | * on \c self. |
162 | * - The caller frees \c rule. |
163 | */ |
164 | void code_props_rule_action_init (code_props *self, char const *code, |
165 | location code_loc, struct symbol_list *rule, |
166 | named_ref *name, uniqstr type, |
167 | bool is_predicate); |
168 | |
169 | /** |
170 | * \pre |
171 | * - If there's a code passage contained in \c self and it contains Bison |
172 | * escapes, all grammar declarations have already been parsed as they may |
173 | * affect warnings and complaints issued here. |
174 | * \post |
175 | * - All M4-special symbols and Bison escapes have been translated in |
176 | * \c self->code. |
177 | * - <tt>self->code != self->code\@pre</tt> unless |
178 | * <tt>self->code\@pre = NULL</tt>. |
179 | */ |
180 | void code_props_translate_code (code_props *self); |
181 | |
182 | /** |
183 | * \pre |
184 | * - None. |
185 | * \post |
186 | * - The dynamic memory allocated by the previous invocation of |
187 | * \c code_props_translate_code (if any) was freed. The \c code_props |
188 | * instance for which \c code_props_translate_code was invoked is now |
189 | * invalid. |
190 | */ |
191 | void code_scanner_last_string_free (void); |
192 | |
193 | /** |
194 | * \pre |
195 | * - None. |
196 | * \post |
197 | * - All dynamic memory allocated during invocations of |
198 | * \c code_props_translate_code (if any) has been freed. All \c code_props |
199 | * instances may now be invalid. |
200 | */ |
201 | void code_scanner_free (void); |
202 | |
203 | #endif /* !SCAN_CODE_H_ */ |
204 | |