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a101b2f8 PK |
1 | /* Copyright (c) 1979 Regents of the University of California */ |
2 | ||
31cef89c | 3 | /* static char sccsid[] = "@(#)yy.h 1.1 8/27/80"; */ |
a101b2f8 PK |
4 | |
5 | #include "y.tab.h" | |
6 | /* | |
7 | * INPUT/OUTPUT | |
8 | */ | |
9 | ||
10 | /* | |
11 | * The buffer for the input file is normally "ibuf". | |
12 | * When files are included, however, this may be | |
13 | * pushed down in the stack of currently active | |
14 | * files. For this reason, the pointer ibp always | |
15 | * references the i/o buffer of the current input file. | |
16 | */ | |
17 | FILE *ibuf, *ibp; | |
18 | ||
19 | /* | |
20 | * Line and token buffers. Charbuf is the character buffer for | |
21 | * input lines, token the buffer for tokens returned | |
22 | * by the scanner. CBSIZE defines the maximum line | |
23 | * length allowed on input and is doubtless too small. | |
24 | * The token buffer should be a local array in yylex. | |
25 | */ | |
26 | #define CBSIZE 161 | |
27 | ||
28 | char charbuf[CBSIZE], *bufp, token[CBSIZE]; | |
29 | ||
30 | #define digit(c) (c >= '0' && c <= '9') | |
31 | #define alph(c) ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) | |
32 | ||
33 | /* | |
34 | * Flag to prevent reprinting current line after | |
35 | * an error. | |
36 | */ | |
37 | char yyprtd; | |
38 | \f | |
39 | /* | |
40 | * The following variables are maintained by | |
41 | * the scanner in the file lex and used in scanning | |
42 | * and in parsing. | |
43 | * | |
44 | * The variable yychar is the current scanner character. | |
45 | * Currently, the scanner must be called as | |
46 | * yychar = yylex() | |
47 | * even though it should set yychar itself. | |
48 | * Yychar has value YEOF at end of file, and negative value if | |
49 | * there is no yychar, e.g. after a shift in the parser. | |
50 | * | |
51 | * The variable yycol is the current column in the line whose number | |
52 | * is given by yyline. Yyecol and yyeline give the position for an | |
53 | * error message to flag, usually the start of an input token. | |
54 | * Yylval is the semantic return from the scanner. | |
55 | * | |
56 | * In fact all of these variables are "per token". | |
57 | * In the usual case, only the copies in the scanner token structure | |
58 | * 'Y' are used, and the #defines below serve to make them look | |
59 | * like variables. | |
60 | * | |
61 | * For the purposes of the error recovery, however, they are copied | |
62 | * and restored quite freely. For the error recovery also, the | |
63 | * file name which the input line this token is on and the seek | |
64 | * pointer of this line in its source file are saved as yyefile | |
65 | * and yyseekp. The global variable yylinpt is the seek pointer | |
66 | * of the current input line. | |
67 | */ | |
68 | int yycol; | |
69 | int yyline; | |
70 | int yyseqid; | |
71 | int yysavc; | |
72 | int yylinpt; | |
73 | ||
74 | /* *** NOTE *** | |
75 | * It would be much better to not have the Yyeline and Yyefile | |
76 | * in the scanner structure and to have a mechanism for mapping | |
77 | * seqid's to these globally. | |
78 | */ | |
79 | struct yytok { | |
80 | int Yychar; | |
81 | int Yylval; | |
82 | int Yyecol; | |
83 | int Yyeline; | |
84 | int Yyseekp; | |
85 | char *Yyefile; | |
86 | int Yyeseqid; | |
87 | } Y, OY; | |
88 | ||
89 | #define yychar Y.Yychar | |
90 | #define yylval Y.Yylval | |
91 | #define yyecol Y.Yyecol | |
92 | #define yyeline Y.Yyeline | |
93 | #define yyseekp Y.Yyseekp | |
94 | #define yyefile Y.Yyefile | |
95 | #define yyeseqid Y.Yyeseqid | |
96 | ||
97 | /* | |
98 | * Yyval is the semantic value returned by a reduction. | |
99 | * It is what "$$" is expanded to by yacc. | |
100 | */ | |
101 | int *Ps, *yyval; | |
102 | ||
103 | /* | |
104 | * N is the length of a reduction. | |
105 | * Used externally by "lineof" to get the left and | |
106 | * right margins for a reduction. | |
107 | */ | |
108 | int N; | |
109 | /* | |
110 | * Definitions for looking up keywords. | |
111 | * The keyword array is called yykey, and | |
112 | * lastkey points at the end of it. | |
113 | */ | |
114 | char *lastkey; | |
115 | ||
116 | struct kwtab { | |
117 | char *kw_str; | |
118 | int kw_val; | |
119 | } yykey[]; | |
120 | \f | |
121 | /* | |
122 | * ERROR RECOVERY EXTERNALS | |
123 | */ | |
124 | ||
125 | #define CLIMIT 40 /* see yyrecover.c */ | |
126 | char *tokname(); | |
127 | char *charname(); | |
128 | ||
129 | char *classes[]; | |
130 | ||
131 | /* | |
132 | * Tokens which yacc doesn't define | |
133 | */ | |
134 | #define YEOF 0 | |
135 | #define ERROR 256 | |
136 | ||
137 | /* | |
138 | * Limit on the number of syntax errors | |
139 | */ | |
140 | #define MAXSYNERR 100 | |
141 | ||
142 | /* | |
143 | * Big costs | |
144 | */ | |
145 | #define HUGE 50 | |
146 | #define INFINITY 100 | |
147 | ||
148 | /* | |
149 | * Kinds of panics | |
150 | */ | |
151 | #define PDECL 0 | |
152 | #define PSTAT 1 | |
153 | #define PEXPR 2 | |
154 | #define PPROG 3 | |
155 | ||
156 | #define yyresume() yyResume = 1; | |
157 | ||
158 | char yyResume; | |
159 | ||
160 | char dquote; | |
161 | ||
162 | char errout; | |
163 | ||
164 | /* | |
165 | * Yyidwant and yyidhave are the namelist classes | |
166 | * of identifiers associated with a identifier reduce | |
167 | * error, set before the recovery is called. | |
168 | * Since they may be set again during the forward move | |
169 | * they must be saved by yyrecover, which uses them in printing | |
170 | * error messages. | |
171 | */ | |
172 | int yyidhave, yyidwant; | |
173 | \f | |
174 | /* | |
175 | * The variables yy*shifts are used to prevent looping and the printing | |
176 | * of spurious messages in the parser. Yyshifts gives the number of | |
177 | * true input shifts since the last corrective action. YyOshifts | |
178 | * is the value of yyshifts before it was last cleared, and is used | |
179 | * by yyPerror in yypanic.c to suppress messages. | |
180 | * | |
181 | * Yytshifts counts true input shifts. It is used to prevent looping | |
182 | * inserting unique symbols. If yytshifts == yyTshifts (local to | |
183 | * yyrecover.c) then there has been no shift over true input since | |
184 | * the last unique symbol insertion. We refuse, in this case, | |
185 | * to insert more unique symbols so as to prevent looping. | |
186 | * | |
187 | * The recovery cannot loop because it guarantees the progress of the | |
188 | * parse, i.e.: | |
189 | * | |
190 | * 1) Any insertion guarantees to shift over 2 symbols, a replacement | |
191 | * over one symbol. | |
192 | * | |
193 | * 2) Unique symbol insertions are limited to one for each true | |
194 | * symbol of input, or "safe" insertion of the keywords "end" | |
195 | * and "until" at zero cost (safe since these are know to match | |
196 | * stack that cannot have been generated - e.g. "begin" or "repeat") | |
197 | * | |
198 | * 3) We never panic more than once from a given state without | |
199 | * shifting over input, i.e. we force the parse stack to shrink | |
200 | * after each unsuccessful panic. | |
201 | */ | |
202 | int yyshifts, yyOshifts; | |
203 | unsigned yytshifts; | |
204 | ||
205 | #ifdef PXP | |
206 | \f | |
207 | /* | |
208 | * Identifier class definitions | |
209 | */ | |
210 | #define UNDEF 0 | |
211 | #define CONST 1 | |
212 | #define TYPE 2 | |
213 | #define VAR 3 | |
214 | #define ARRAY 4 | |
215 | #define PTRFILE 5 | |
216 | #define RECORD 6 | |
217 | #define FIELD 7 | |
218 | #define PROC 8 | |
219 | #define FUNC 9 | |
220 | #define FVAR 10 | |
221 | #define REF 11 | |
222 | #define PTR 12 | |
223 | #define FILET 13 | |
224 | #define SET 14 | |
225 | #define RANGE 15 | |
226 | #define LABEL 16 | |
227 | #define WITHPTR 17 | |
228 | #define SCAL 18 | |
229 | #define STR 19 | |
230 | #define PROG 20 | |
231 | #define IMPROPER 21 | |
232 | \f | |
233 | /* | |
234 | * COMMENT FORMATTING DEFINITIONS | |
235 | */ | |
236 | ||
237 | /* | |
238 | * Count of tokens on this input line | |
239 | * Note that this can be off if input is not syntactically correct. | |
240 | */ | |
241 | int yytokcnt; | |
242 | int yywhcnt; | |
243 | ||
244 | /* | |
245 | * Types of comments | |
246 | */ | |
247 | #define CLMARG 0 | |
248 | #define CALIGN 1 | |
249 | #define CTRAIL 2 | |
250 | #define CRMARG 3 | |
251 | #define CSRMARG 4 | |
252 | #define CNL 5 | |
253 | #define CNLBL 6 | |
254 | #define CFORM 7 | |
255 | #define CINCLUD 8 | |
256 | ||
257 | /* | |
258 | * Comment structure | |
259 | * Cmhp is the head of the current list of comments | |
260 | */ | |
261 | struct comment { | |
262 | struct comment *cmnext; | |
263 | int cmdelim; | |
264 | struct commline *cml; | |
265 | int cmjust; | |
266 | int cmseqid; | |
267 | } *cmhp; | |
268 | ||
269 | /* | |
270 | * Structure for holding a comment line | |
271 | */ | |
272 | struct commline { | |
273 | char *cmtext; | |
274 | int cmcol; /* Only used for first line of comment currently */ | |
275 | struct commline *cml; | |
276 | }; | |
277 | ||
278 | struct W { | |
279 | int Wseqid; | |
280 | int Wcol; | |
281 | } yyw[MAXDEPTH + 1], *yypw; | |
282 | ||
283 | #define commform() quickcomm(CFORM) | |
284 | #define commnl() quickcomm(CNL) | |
285 | #define commnlbl() quickcomm(CNLBL) | |
286 | #endif |