![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to yy.h CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [CSRG BSD Unix] / 3BSD / cmd / pxp|
Return to yy.h CVS log | Up to [CSRG BSD Unix] / 3BSD / cmd / pxp |
1.1 root 1: /* Copyright (c) 1979 Regents of the University of California */
2: #
3: /*
4: * pi - Pascal interpreter code translator
5: *
6: * Charles Haley, Bill Joy UCB
7: * Version 1.1 February 1978
8: *
9: *
10: * pxp - Pascal execution profiler
11: *
12: * Bill Joy UCB
13: * Version 1.1 February 1978
14: */
15:
16: #include "y.tab.h"
17: /*
18: * INPUT/OUTPUT
19: */
20:
21: /*
22: * The buffer for the input file is normally "ibuf".
23: * When files are included, however, this may be
24: * pushed down in the stack of currently active
25: * files. For this reason, the pointer ibp always
26: * references the i/o buffer of the current input file.
27: */
28: FILE *ibuf, *ibp;
29:
30: /*
31: * Line and token buffers. Charbuf is the character buffer for
32: * input lines, token the buffer for tokens returned
33: * by the scanner. CBSIZE defines the maximum line
34: * length allowed on input and is doubtless too small.
35: * The token buffer should be a local array in yylex.
36: */
37: #define CBSIZE 161
38:
39: char charbuf[CBSIZE], *bufp, token[CBSIZE];
40:
41: #define digit(c) (c >= '0' && c <= '9')
42: #define alph(c) ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
43:
44: /*
45: * Flag to prevent reprinting current line after
46: * an error.
47: */
48: char yyprtd;
49:
50: /*
51: * The following variables are maintained by
52: * the scanner in the file lex and used in scanning
53: * and in parsing.
54: *
55: * The variable yychar is the current scanner character.
56: * Currently, the scanner must be called as
57: * yychar = yylex()
58: * even though it should set yychar itself.
59: * Yychar has value YEOF at end of file, and negative value if
60: * there is no yychar, e.g. after a shift in the parser.
61: *
62: * The variable yycol is the current column in the line whose number
63: * is given by yyline. Yyecol and yyeline give the position for an
64: * error message to flag, usually the start of an input token.
65: * Yylval is the semantic return from the scanner.
66: *
67: * In fact all of these variables are "per token".
68: * In the usual case, only the copies in the scanner token structure
69: * 'Y' are used, and the #defines below serve to make them look
70: * like variables.
71: *
72: * For the purposes of the error recovery, however, they are copied
73: * and restored quite freely. For the error recovery also, the
74: * file name which the input line this token is on and the seek
75: * pointer of this line in its source file are saved as yyefile
76: * and yyseekp. The global variable yylinpt is the seek pointer
77: * of the current input line.
78: */
79: int yycol;
80: int yyline;
81: int yyseqid;
82: int yysavc;
83: int yylinpt;
84:
85: /* *** NOTE ***
86: * It would be much better to not have the Yyeline and Yyefile
87: * in the scanner structure and to have a mechanism for mapping
88: * seqid's to these globally.
89: */
90: struct yytok {
91: int Yychar;
92: int Yylval;
93: int Yyecol;
94: int Yyeline;
95: int Yyseekp;
96: char *Yyefile;
97: int Yyeseqid;
98: } Y, OY;
99:
100: #define yychar Y.Yychar
101: #define yylval Y.Yylval
102: #define yyecol Y.Yyecol
103: #define yyeline Y.Yyeline
104: #define yyseekp Y.Yyseekp
105: #define yyefile Y.Yyefile
106: #define yyeseqid Y.Yyeseqid
107:
108: /*
109: * Yyval is the semantic value returned by a reduction.
110: * It is what "$$" is expanded to by yacc.
111: */
112: int *Ps, *yyval;
113:
114: /*
115: * N is the length of a reduction.
116: * Used externally by "lineof" to get the left and
117: * right margins for a reduction.
118: */
119: int N;
120: /*
121: * Definitions for looking up keywords.
122: * The keyword array is called yykey, and
123: * lastkey points at the end of it.
124: */
125: char *lastkey;
126:
127: struct kwtab {
128: char *kw_str;
129: int kw_val;
130: } yykey[];
131:
132: /*
133: * ERROR RECOVERY EXTERNALS
134: */
135:
136: #define CLIMIT 40 /* see yyrecover.c */
137: char *tokname();
138: char *charname();
139:
140: char *classes[];
141:
142: /*
143: * Tokens which yacc doesn't define
144: */
145: #define YEOF 0
146: #define ERROR 256
147:
148: /*
149: * Limit on the number of syntax errors
150: */
151: #define MAXSYNERR 100
152:
153: /*
154: * Big costs
155: */
156: #define HUGE 50
157: #define INFINITY 100
158:
159: /*
160: * Kinds of panics
161: */
162: #define PDECL 0
163: #define PSTAT 1
164: #define PEXPR 2
165: #define PPROG 3
166:
167: #define yyresume() yyResume = 1;
168:
169: char yyResume;
170:
171: char dquote;
172:
173: char errout;
174:
175: /*
176: * Yyidwant and yyidhave are the namelist classes
177: * of identifiers associated with a identifier reduce
178: * error, set before the recovery is called.
179: * Since they may be set again during the forward move
180: * they must be saved by yyrecover, which uses them in printing
181: * error messages.
182: */
183: int yyidhave, yyidwant;
184:
185: /*
186: * The variables yy*shifts are used to prevent looping and the printing
187: * of spurious messages in the parser. Yyshifts gives the number of
188: * true input shifts since the last corrective action. YyOshifts
189: * is the value of yyshifts before it was last cleared, and is used
190: * by yyPerror in yypanic.c to suppress messages.
191: *
192: * Yytshifts counts true input shifts. It is used to prevent looping
193: * inserting unique symbols. If yytshifts == yyTshifts (local to
194: * yyrecover.c) then there has been no shift over true input since
195: * the last unique symbol insertion. We refuse, in this case,
196: * to insert more unique symbols so as to prevent looping.
197: *
198: * The recovery cannot loop because it guarantees the progress of the
199: * parse, i.e.:
200: *
201: * 1) Any insertion guarantees to shift over 2 symbols, a replacement
202: * over one symbol.
203: *
204: * 2) Unique symbol insertions are limited to one for each true
205: * symbol of input, or "safe" insertion of the keywords "end"
206: * and "until" at zero cost (safe since these are know to match
207: * stack that cannot have been generated - e.g. "begin" or "repeat")
208: *
209: * 3) We never panic more than once from a given state without
210: * shifting over input, i.e. we force the parse stack to shrink
211: * after each unsuccessful panic.
212: */
213: int yyshifts, yyOshifts;
214: unsigned yytshifts;
215:
216: #ifdef PXP
217:
218: /*
219: * Identifier class definitions
220: */
221: #define UNDEF 0
222: #define CONST 1
223: #define TYPE 2
224: #define VAR 3
225: #define ARRAY 4
226: #define PTRFILE 5
227: #define RECORD 6
228: #define FIELD 7
229: #define PROC 8
230: #define FUNC 9
231: #define FVAR 10
232: #define REF 11
233: #define PTR 12
234: #define FILET 13
235: #define SET 14
236: #define RANGE 15
237: #define LABEL 16
238: #define WITHPTR 17
239: #define SCAL 18
240: #define STR 19
241: #define PROG 20
242: #define IMPROPER 21
243:
244: /*
245: * COMMENT FORMATTING DEFINITIONS
246: */
247:
248: /*
249: * Count of tokens on this input line
250: * Note that this can be off if input is not syntactically correct.
251: */
252: int yytokcnt;
253: int yywhcnt;
254:
255: /*
256: * Types of comments
257: */
258: #define CLMARG 0
259: #define CALIGN 1
260: #define CTRAIL 2
261: #define CRMARG 3
262: #define CSRMARG 4
263: #define CNL 5
264: #define CNLBL 6
265: #define CFORM 7
266: #define CINCLUD 8
267:
268: /*
269: * Comment structure
270: * Cmhp is the head of the current list of comments
271: */
272: struct comment {
273: struct comment *cmnext;
274: int cmdelim;
275: struct commline *cml;
276: int cmjust;
277: int cmseqid;
278: } *cmhp;
279:
280: /*
281: * Structure for holding a comment line
282: */
283: struct commline {
284: char *cmtext;
285: int cmcol; /* Only used for first line of comment currently */
286: struct commline *cml;
287: };
288:
289: struct W {
290: int Wseqid;
291: int Wcol;
292: } yyw[MAXDEPTH + 1], *yypw;
293:
294: #define commform() quickcomm(CFORM)
295: #define commnl() quickcomm(CNL)
296: #define commnlbl() quickcomm(CNLBL)
297: #endif
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.