2 #define yyclearin yychar = -1
3 #define yyerrok yyerrflag = 0
9 char* yytoknames[1]; /* for debugging */
10 char* yystates[1]; /* for debugging */
13 /* parser for yacc output */
15 int yynerrs = 0; /* number of errors */
16 int yyerrflag = 0; /* error recovery flag */
18 extern int fprint(int, char*, ...);
19 extern int sprint(char*, char*, ...);
26 if(yyc > 0 && yyc <= sizeof(yytoknames)/sizeof(yytoknames[0]))
28 return yytoknames[yyc-1];
29 sprint(x, "<%d>", yyc);
38 if(yys >= 0 && yys < sizeof(yystates)/sizeof(yystates[0]))
41 sprint(x, "<%d>\n", yys);
57 if(yychar < sizeof(yytok1)/sizeof(yytok1[0])) {
61 if(yychar >= YYPRIVATE)
62 if(yychar < YYPRIVATE+sizeof(yytok2)/sizeof(yytok2[0])) {
63 c = yytok2[yychar-YYPRIVATE];
66 for(t3p=yytok3;; t3p+=2) {
79 c = yytok2[1]; /* unknown char */
81 fprint(2, "lex %.4lux %s\n", yychar, yytokname(c));
92 } yys[YYMAXDEPTH], *yyp, *yypt;
94 int yyj, yym, yystate, yyn, yyg;
127 /* put a state and value onto the stack */
129 fprint(2, "char %s in %s", yytokname(yychar), yystatname(yystate));
132 if(yyp >= &yys[YYMAXDEPTH]) {
133 yyerror("yacc stack overflow");
140 yyn = yypact[yystate];
142 goto yydefault; /* simple state */
146 if(yyn < 0 || yyn >= YYLAST)
149 if(yychk[yyn] == yychar) { /* valid shift */
159 /* default state action */
160 yyn = yydef[yystate];
165 /* look through exception table */
166 for(yyxi=yyexca;; yyxi+=2)
167 if(yyxi[0] == -1 && yyxi[1] == yystate)
169 for(yyxi += 2;; yyxi += 2) {
171 if(yyn < 0 || yyn == yychar)
179 /* error ... attempt to resume parsing */
181 case 0: /* brand new error */
182 yyerror("syntax error");
185 fprint(2, "%s", yystatname(yystate));
186 fprint(2, "saw %s\n", yytokname(yychar));
190 case 2: /* incompletely recovered error ... try again */
193 /* find a state where "error" is a legal shift action */
195 yyn = yypact[yyp->yys] + YYERRCODE;
196 if(yyn >= 0 && yyn < YYLAST) {
197 yystate = yyact[yyn]; /* simulate a shift of "error" */
198 if(yychk[yystate] == YYERRCODE)
202 /* the current yyp has no shift onn "error", pop stack */
204 fprint(2, "error recovery pops state %d, uncovers %d\n",
205 yyp->yys, (yyp-1)->yys );
208 /* there is no state on the stack with an error shift ... abort */
211 case 3: /* no shift yet; clobber input char */
213 fprint(2, "error recovery discards %s\n", yytokname(yychar));
214 if(yychar == YYEOFCODE)
217 goto yynewstate; /* try again in the same state */
221 /* reduction by production yyn */
223 fprint(2, "reduce %d in:\n\t%s", yyn, yystatname(yystate));
227 yyval = (yyp+1)->yyv;
230 /* consult goto table to find next state */
233 yyj = yyg + yyp->yys + 1;
235 if(yyj >= YYLAST || yychk[yystate=yyact[yyj]] != -yyn)
236 yystate = yyact[yyg];
240 goto yystack; /* stack new state and value */