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