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1.1 root 1: #
2: /*
3: * pi - Pascal interpreter code translator
4: *
5: * Charles Haley, Bill Joy UCB
6: * Version 1.2 November 1978
7: *
8: *
9: * pxp - Pascal execution profiler
10: *
11: * Bill Joy UCB
12: * Version 1.2 November 1978
13: */
14:
15: #include "y.tab.h"
16: /*
17: * INPUT/OUTPUT
18: */
19:
20: /*
21: * The buffer for the input file is normally "ibuf".
22: * When files are included, however, this may be
23: * pushed down in the stack of currently active
24: * files. For this reason, the pointer ibp always
25: * references the i/o buffer of the current input file.
26: */
27: FILE *ibuf, *ibp;
28:
29: /*
30: * Line and token buffers. Charbuf is the character buffer for
31: * input lines, token the buffer for tokens returned
32: * by the scanner. CBSIZE defines the maximum line
33: * length allowed on input and is doubtless too small.
34: * The token buffer should be a local array in yylex.
35: */
36: #define CBSIZE 161
37:
38: char charbuf[CBSIZE], *bufp, token[CBSIZE];
39:
40: #define digit(c) (c >= '0' && c <= '9')
41: #define alph(c) ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
42:
43: /*
44: * Flag to prevent reprinting current line after
45: * an error.
46: */
47: char yyprtd;
48:
49: /*
50: * The following variables are maintained by
51: * the scanner in the file lex and used in scanning
52: * and in parsing.
53: *
54: * The variable yychar is the current scanner character.
55: * Currently, the scanner must be called as
56: * yychar = yylex()
57: * even though it should set yychar itself.
58: * Yychar has value YEOF at end of file, and negative value if
59: * there is no yychar, e.g. after a shift in the parser.
60: *
61: * The variable yycol is the current column in the line whose number
62: * is given by yyline. Yyecol and yyeline give the position for an
63: * error message to flag, usually the start of an input token.
64: * Yylval is the semantic return from the scanner.
65: *
66: * In fact all of these variables are "per token".
67: * In the usual case, only the copies in the scanner token structure
68: * 'Y' are used, and the #defines below serve to make them look
69: * like variables.
70: *
71: * For the purposes of the error recovery, however, they are copied
72: * and restored quite freely. For the error recovery also, the
73: * file name which the input line this token is on and the seek
74: * pointer of this line in its source file are saved as yyefile
75: * and yyseekp. The global variable yylinpt is the seek pointer
76: * of the current input line.
77: */
78: int yycol;
79: int yyline;
80: int yyseqid;
81: int yysavc;
82: int yylinpt;
83:
84: /* *** NOTE ***
85: * It would be much better to not have the Yyeline and Yyefile
86: * in the scanner structure and to have a mechanism for mapping
87: * seqid's to these globally.
88: */
89: struct yytok {
90: int Yychar;
91: int Yylval;
92: int Yyecol;
93: int Yyeline;
94: int Yyseekp;
95: char *Yyefile;
96: int Yyeseqid;
97: } Y, OY;
98:
99: #define yychar Y.Yychar
100: #define yylval Y.Yylval
101: #define yyecol Y.Yyecol
102: #define yyeline Y.Yyeline
103: #define yyseekp Y.Yyseekp
104: #define yyefile Y.Yyefile
105: #define yyeseqid Y.Yyeseqid
106:
107: /*
108: * Yyval is the semantic value returned by a reduction.
109: * It is what "$$" is expanded to by yacc.
110: */
111: int *Ps, *yyval;
112:
113: /*
114: * N is the length of a reduction.
115: * Used externally by "lineof" to get the left and
116: * right margins for a reduction.
117: */
118: int N;
119: /*
120: * Definitions for looking up keywords.
121: * The keyword array is called yykey, and
122: * lastkey points at the end of it.
123: */
124: char *lastkey;
125:
126: struct kwtab {
127: char *kw_str;
128: int kw_val;
129: } yykey[];
130:
131: /*
132: * ERROR RECOVERY EXTERNALS
133: */
134:
135: #define CLIMIT 40 /* see yyrecover.c */
136: char *tokname();
137: char *charname();
138:
139: char *classes[];
140:
141: /*
142: * Tokens which yacc doesn't define
143: */
144: #define YEOF 0
145: #define ERROR 256
146:
147: /*
148: * Limit on the number of syntax errors
149: */
150: #define MAXSYNERR 100
151:
152: /*
153: * Big costs
154: */
155: #define HUGE 50
156: #define INFINITY 100
157:
158: /*
159: * Kinds of panics
160: */
161: #define PDECL 0
162: #define PSTAT 1
163: #define PEXPR 2
164: #define PPROG 3
165:
166: #define yyresume() yyResume = 1;
167:
168: char yyResume;
169:
170: char dquote;
171:
172: char errout;
173:
174: /*
175: * Yyidwant and yyidhave are the namelist classes
176: * of identifiers associated with a identifier reduce
177: * error, set before the recovery is called.
178: * Since they may be set again during the forward move
179: * they must be saved by yyrecover, which uses them in printing
180: * error messages.
181: */
182: int yyidhave, yyidwant;
183:
184: /*
185: * The variables yy*shifts are used to prevent looping and the printing
186: * of spurious messages in the parser. Yyshifts gives the number of
187: * true input shifts since the last corrective action. YyOshifts
188: * is the value of yyshifts before it was last cleared, and is used
189: * by yyPerror in yypanic.c to suppress messages.
190: *
191: * Yytshifts counts true input shifts. It is used to prevent looping
192: * inserting unique symbols. If yytshifts == yyTshifts (local to
193: * yyrecover.c) then there has been no shift over true input since
194: * the last unique symbol insertion. We refuse, in this case,
195: * to insert more unique symbols so as to prevent looping.
196: *
197: * The recovery cannot loop because it guarantees the progress of the
198: * parse, i.e.:
199: *
200: * 1) Any insertion guarantees to shift over 2 symbols, a replacement
201: * over one symbol.
202: *
203: * 2) Unique symbol insertions are limited to one for each true
204: * symbol of input, or "safe" insertion of the keywords "end"
205: * and "until" at zero cost (safe since these are know to match
206: * stack that cannot have been generated - e.g. "begin" or "repeat")
207: *
208: * 3) We never panic more than once from a given state without
209: * shifting over input, i.e. we force the parse stack to shrink
210: * after each unsuccessful panic.
211: */
212: int yyshifts, yyOshifts;
213: unsigned yytshifts;
214:
215: #ifdef PXP
216:
217: /*
218: * Identifier class definitions
219: */
220: #define UNDEF 0
221: #define CONST 1
222: #define TYPE 2
223: #define VAR 3
224: #define ARRAY 4
225: #define PTRFILE 5
226: #define RECORD 6
227: #define FIELD 7
228: #define PROC 8
229: #define FUNC 9
230: #define FVAR 10
231: #define REF 11
232: #define PTR 12
233: #define FILET 13
234: #define SET 14
235: #define RANGE 15
236: #define LABEL 16
237: #define WITHPTR 17
238: #define SCAL 18
239: #define STR 19
240: #define PROG 20
241: #define IMPROPER 21
242:
243: /*
244: * COMMENT FORMATTING DEFINITIONS
245: */
246:
247: /*
248: * Count of tokens on this input line
249: * Note that this can be off if input is not syntactically correct.
250: */
251: int yytokcnt;
252: int yywhcnt;
253:
254: /*
255: * Types of comments
256: */
257: #define CLMARG 0
258: #define CALIGN 1
259: #define CTRAIL 2
260: #define CRMARG 3
261: #define CSRMARG 4
262: #define CNL 5
263: #define CNLBL 6
264: #define CFORM 7
265: #define CINCLUD 8
266:
267: /*
268: * Comment structure
269: * Cmhp is the head of the current list of comments
270: */
271: struct comment {
272: struct comment *cmnext;
273: int cmdelim;
274: struct commline *cml;
275: int cmjust;
276: int cmseqid;
277: } *cmhp;
278:
279: /*
280: * Structure for holding a comment line
281: */
282: struct commline {
283: char *cmtext;
284: int cmcol; /* Only used for first line of comment currently */
285: struct commline *cml;
286: };
287:
288: struct W {
289: int Wseqid;
290: int Wcol;
291: } yyw[MAXDEPTH + 1], *yypw;
292:
293: #define commform() quickcomm(CFORM)
294: #define commnl() quickcomm(CNL)
295: #define commnlbl() quickcomm(CNLBL)
296: #endif
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