these belong elsewhere, but where?

1 files changed, 241 insertions, 0 deletions

diff --git a/lib/yaccpar b/lib/yaccpar
new file mode 100644
index 00000000..efc1da06
--- /dev/null
+++ b/lib/yaccpar
@@ -0,0 +1,241 @@
+#define YYFLAG 		-1000
+#define	yyclearin	yychar = -1
+#define	yyerrok		yyerrflag = 0
+
+#ifdef	yydebug
+#include	"y.debug"
+#else
+#define	yydebug		0
+char*	yytoknames[1];		/* for debugging */
+char*	yystates[1];		/* for debugging */
+#endif
+
+/*	parser for yacc output	*/
+
+int	yynerrs = 0;		/* number of errors */
+int	yyerrflag = 0;		/* error recovery flag */
+
+extern	int	fprint(int, char*, ...);
+extern	int	sprint(char*, char*, ...);
+
+char*
+yytokname(int yyc)
+{
+	static char x[10];
+
+	if(yyc > 0 && yyc <= sizeof(yytoknames)/sizeof(yytoknames[0]))
+	if(yytoknames[yyc-1])
+		return yytoknames[yyc-1];
+	sprint(x, "<%d>", yyc);
+	return x;
+}
+
+char*
+yystatname(int yys)
+{
+	static char x[10];
+
+	if(yys >= 0 && yys < sizeof(yystates)/sizeof(yystates[0]))
+	if(yystates[yys])
+		return yystates[yys];
+	sprint(x, "<%d>\n", yys);
+	return x;
+}
+
+long
+yylex1(void)
+{
+	long yychar;
+	long *t3p;
+	int c;
+
+	yychar = yylex();
+	if(yychar <= 0) {
+		c = yytok1[0];
+		goto out;
+	}
+	if(yychar < sizeof(yytok1)/sizeof(yytok1[0])) {
+		c = yytok1[yychar];
+		goto out;
+	}
+	if(yychar >= YYPRIVATE)
+		if(yychar < YYPRIVATE+sizeof(yytok2)/sizeof(yytok2[0])) {
+			c = yytok2[yychar-YYPRIVATE];
+			goto out;
+		}
+	for(t3p=yytok3;; t3p+=2) {
+		c = t3p[0];
+		if(c == yychar) {
+			c = t3p[1];
+			goto out;
+		}
+		if(c == 0)
+			break;
+	}
+	c = 0;
+
+out:
+	if(c == 0)
+		c = yytok2[1];	/* unknown char */
+	if(yydebug >= 3)
+		fprint(2, "lex %.4lux %s\n", yychar, yytokname(c));
+	return c;
+}
+
+int
+yyparse(void)
+{
+	struct
+	{
+		YYSTYPE	yyv;
+		int	yys;
+	} yys[YYMAXDEPTH], *yyp, *yypt;
+	short *yyxi;
+	int yyj, yym, yystate, yyn, yyg;
+	long yychar;
+	YYSTYPE save1, save2;
+	int save3, save4;
+
+	save1 = yylval;
+	save2 = yyval;
+	save3 = yynerrs;
+	save4 = yyerrflag;
+
+	yystate = 0;
+	yychar = -1;
+	yynerrs = 0;
+	yyerrflag = 0;
+	yyp = &yys[-1];
+	goto yystack;
+
+ret0:
+	yyn = 0;
+	goto ret;
+
+ret1:
+	yyn = 1;
+	goto ret;
+
+ret:
+	yylval = save1;
+	yyval = save2;
+	yynerrs = save3;
+	yyerrflag = save4;
+	return yyn;
+
+yystack:
+	/* put a state and value onto the stack */
+	if(yydebug >= 4)
+		fprint(2, "char %s in %s", yytokname(yychar), yystatname(yystate));
+
+	yyp++;
+	if(yyp >= &yys[YYMAXDEPTH]) {
+		yyerror("yacc stack overflow");
+		goto ret1;
+	}
+	yyp->yys = yystate;
+	yyp->yyv = yyval;
+
+yynewstate:
+	yyn = yypact[yystate];
+	if(yyn <= YYFLAG)
+		goto yydefault; /* simple state */
+	if(yychar < 0)
+		yychar = yylex1();
+	yyn += yychar;
+	if(yyn < 0 || yyn >= YYLAST)
+		goto yydefault;
+	yyn = yyact[yyn];
+	if(yychk[yyn] == yychar) { /* valid shift */
+		yychar = -1;
+		yyval = yylval;
+		yystate = yyn;
+		if(yyerrflag > 0)
+			yyerrflag--;
+		goto yystack;
+	}
+
+yydefault:
+	/* default state action */
+	yyn = yydef[yystate];
+	if(yyn == -2) {
+		if(yychar < 0)
+			yychar = yylex1();
+
+		/* look through exception table */
+		for(yyxi=yyexca;; yyxi+=2)
+			if(yyxi[0] == -1 && yyxi[1] == yystate)
+				break;
+		for(yyxi += 2;; yyxi += 2) {
+			yyn = yyxi[0];
+			if(yyn < 0 || yyn == yychar)
+				break;
+		}
+		yyn = yyxi[1];
+		if(yyn < 0)
+			goto ret0;
+	}
+	if(yyn == 0) {
+		/* error ... attempt to resume parsing */
+		switch(yyerrflag) {
+		case 0:   /* brand new error */
+			yyerror("syntax error");
+			yynerrs++;
+			if(yydebug >= 1) {
+				fprint(2, "%s", yystatname(yystate));
+				fprint(2, "saw %s\n", yytokname(yychar));
+			}
+
+		case 1:
+		case 2: /* incompletely recovered error ... try again */
+			yyerrflag = 3;
+
+			/* find a state where "error" is a legal shift action */
+			while(yyp >= yys) {
+				yyn = yypact[yyp->yys] + YYERRCODE;
+				if(yyn >= 0 && yyn < YYLAST) {
+					yystate = yyact[yyn];  /* simulate a shift of "error" */
+					if(yychk[yystate] == YYERRCODE)
+						goto yystack;
+				}
+
+				/* the current yyp has no shift onn "error", pop stack */
+				if(yydebug >= 2)
+					fprint(2, "error recovery pops state %d, uncovers %d\n",
+						yyp->yys, (yyp-1)->yys );
+				yyp--;
+			}
+			/* there is no state on the stack with an error shift ... abort */
+			goto ret1;
+
+		case 3:  /* no shift yet; clobber input char */
+			if(yydebug >= 2)
+				fprint(2, "error recovery discards %s\n", yytokname(yychar));
+			if(yychar == YYEOFCODE)
+				goto ret1;
+			yychar = -1;
+			goto yynewstate;   /* try again in the same state */
+		}
+	}
+
+	/* reduction by production yyn */
+	if(yydebug >= 2)
+		fprint(2, "reduce %d in:\n\t%s", yyn, yystatname(yystate));
+
+	yypt = yyp;
+	yyp -= yyr2[yyn];
+	yyval = (yyp+1)->yyv;
+	yym = yyn;
+
+	/* consult goto table to find next state */
+	yyn = yyr1[yyn];
+	yyg = yypgo[yyn];
+	yyj = yyg + yyp->yys + 1;
+
+	if(yyj >= YYLAST || yychk[yystate=yyact[yyj]] != -yyn)
+		yystate = yyact[yyg];
+	switch(yym) {
+		$A
+	}
+	goto yystack;  /* stack new state and value */
+}