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1 | /* Prepare the LALR and GLR parser tables. | |
2 | ||
3 | Copyright (C) 2002, 2004, 2009, 2010 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 TABLES_H_ | |
21 | # define TABLES_H_ | |
22 | ||
23 | # include "state.h" | |
24 | ||
25 | /* The parser tables consist of these tables. | |
26 | ||
27 | YYTRANSLATE = vector mapping yylex's token numbers into bison's | |
28 | token numbers. | |
29 | ||
30 | YYTNAME = vector of string-names indexed by bison token number. | |
31 | ||
32 | YYTOKNUM = vector of yylex token numbers corresponding to entries | |
33 | in YYTNAME. | |
34 | ||
35 | YYRLINE = vector of line-numbers of all rules. For yydebug | |
36 | printouts. | |
37 | ||
38 | YYRHS = vector of items of all rules. This is exactly what RITEMS | |
39 | contains. For yydebug and for semantic parser. | |
40 | ||
41 | YYPRHS[R] = index in YYRHS of first item for rule R. | |
42 | ||
43 | YYR1[R] = symbol number of symbol that rule R derives. | |
44 | ||
45 | YYR2[R] = number of symbols composing right hand side of rule R. | |
46 | ||
47 | YYSTOS[S] = the symbol number of the symbol that leads to state S. | |
48 | ||
49 | YYFINAL = the state number of the termination state. | |
50 | ||
51 | YYTABLE = a vector filled with portions for different uses, found | |
52 | via YYPACT and YYPGOTO, described below. | |
53 | ||
54 | YYLAST ( = high) the number of the last element of YYTABLE, i.e., | |
55 | sizeof (YYTABLE) - 1. | |
56 | ||
57 | YYCHECK = a vector indexed in parallel with YYTABLE. It indicates, | |
58 | in a roundabout way, the bounds of the portion you are trying to | |
59 | examine. | |
60 | ||
61 | Suppose that the portion of YYTABLE starts at index P and the index | |
62 | to be examined within the portion is I. Then if YYCHECK[P+I] != I, | |
63 | I is outside the bounds of what is actually allocated, and the | |
64 | default (from YYDEFACT or YYDEFGOTO) should be used. Otherwise, | |
65 | YYTABLE[P+I] should be used. | |
66 | ||
67 | YYDEFACT[S] = default reduction number in state s. Performed when | |
68 | YYTABLE doesn't specify something else to do. Zero means the default | |
69 | is an error. | |
70 | ||
71 | YYDEFGOTO[I] = default state to go to after a reduction of a rule | |
72 | that generates variable NTOKENS + I, except when YYTABLE specifies | |
73 | something else to do. | |
74 | ||
75 | YYPACT[S] = index in YYTABLE of the portion describing state S. | |
76 | The lookahead token's number, I, is used to index that portion of | |
77 | YYTABLE to find out what action to perform. | |
78 | ||
79 | If YYPACT[S] == YYPACT_NINF, if YYPACT[S] + I is outside the bounds | |
80 | of YYTABLE (from 0 to YYLAST), or I is outside the bounds for portion | |
81 | S (that is, YYCHECK[YYPACT[S] + I] != I), then the default action | |
82 | (that is, YYDEFACT[S]) should be used instead of YYTABLE. Otherwise, | |
83 | the value YYTABLE[YYPACT[S] + I] should be used even if | |
84 | YYPACT[S] < 0. | |
85 | ||
86 | If the value in YYTABLE is positive, we shift the token and go to | |
87 | that state. | |
88 | ||
89 | If the value is negative, it is minus a rule number to reduce by. | |
90 | ||
91 | If the value is YYTABLE_NINF, it's a syntax error. | |
92 | ||
93 | YYPGOTO[I] = the index in YYTABLE of the portion describing what to | |
94 | do after reducing a rule that derives variable I + NTOKENS. This | |
95 | portion is indexed by the parser state number, S, as of before the | |
96 | text for this nonterminal was read. | |
97 | ||
98 | If YYPGOTO[I] + S is outside the bounds of YYTABLE (from 0 to YYLAST) | |
99 | or if S is outside the bounds of the portion for I (that is, | |
100 | YYCHECK[YYPGOTO[I] + S] != S), then the default state (that is, | |
101 | YYDEFGOTO[I]) should be used instead of YYTABLE. Otherwise, | |
102 | YYTABLE[YYPGOTO[I] + S] is the state to go to even if YYPGOTO[I] < 0. | |
103 | ||
104 | When the above YYPACT, YYPGOTO, and YYCHECK tests determine that a | |
105 | value from YYTABLE should be used, that value is never zero, so it is | |
106 | useless to check for zero. When those tests indicate that the value | |
107 | from YYDEFACT or YYDEFGOTO should be used instead, the value from | |
108 | YYTABLE *might* be zero, which, as a consequence of the way in which | |
109 | the tables are constructed, also happens to indicate that YYDEFACT or | |
110 | YYDEFGOTO should be used. However, the YYTABLE value cannot be | |
111 | trusted when the YYDEFACT or YYDEFGOTO value should be used. In | |
112 | summary, forget about zero values in YYTABLE. | |
113 | */ | |
114 | ||
115 | extern int nvectors; | |
116 | ||
117 | typedef int base_number; | |
118 | extern base_number *base; | |
119 | /* A distinguished value of BASE, negative infinite. During the | |
120 | computation equals to BASE_MINIMUM, later mapped to BASE_NINF to | |
121 | keep parser tables small. */ | |
122 | extern base_number base_ninf; | |
123 | ||
124 | extern unsigned int *conflict_table; | |
125 | extern unsigned int *conflict_list; | |
126 | extern int conflict_list_cnt; | |
127 | ||
128 | extern base_number *table; | |
129 | extern base_number *check; | |
130 | /* The value used in TABLE to denote explicit syntax errors | |
131 | (%nonassoc), a negative infinite. */ | |
132 | extern base_number table_ninf; | |
133 | ||
134 | extern state_number *yydefgoto; | |
135 | extern rule_number *yydefact; | |
136 | extern int high; | |
137 | ||
138 | void tables_generate (void); | |
139 | void tables_free (void); | |
140 | ||
141 | #endif /* !TABLES_H_ */ |