shithub: kwa

--- a/awk.h

+++ b/awk.h

@@ -42,6 +42,8 @@

 extern int	donerec;	/* 1 if record is valid (no fld has changed */

 extern char	inputFS[];	/* FS at time of input, for field splitting */

+extern char	EMPTY[];

 extern int	dbg;

 extern	char	*patbeg;	/* beginning of pattern matched */

--- a/lex.c

+++ b/lex.c

@@ -285,7 +285,7 @@

 					unputstr("(NF)");

 					RET(INDIRECT);

-				yylval.cp = setsymtab(buf, "", 0.0, STR|NUM, symtab);

+				yylval.cp = setsymtab(buf, EMPTY, 0.0, STR|NUM, symtab);

 				RET(IVAR);

 			} else {

 				unputstr(buf);

@@ -446,7 +446,7 @@

 				SYNTAX( "return not in function" );

 			RET(kp->type);

 		case VARNF:

-			yylval.cp = setsymtab("NF", "", 0.0, NUM, symtab);

+			yylval.cp = setsymtab("NF", EMPTY, 0.0, NUM, symtab);

 			RET(VARNF);

 		default:

 			RET(kp->type);

@@ -457,7 +457,7 @@

 		yylval.i = n;

 		RET(ARG);

 	} else {

-		yylval.cp = setsymtab(w, "", 0.0, STR|NUM|DONTFREE, symtab);

+		yylval.cp = setsymtab(w, EMPTY, 0.0, STR|NUM|DONTFREE, symtab);

 		if (c == '(') {

 			RET(CALL);

 		} else {

--- a/lib.c

+++ b/lib.c

@@ -6,7 +6,7 @@

 #include "y.tab.h"

 Biobuf	*infile;

-char	*file	= "";

+char	*file	= EMPTY;

 char	*record;

 int	recsize	= RECSIZE;

 char	*fields;

@@ -25,8 +25,8 @@

 int	argno	= 1;	/* current input argument number */

 extern	Awkfloat *AARGC;

-static Cell dollar0 = { OCELL, CFLD, nil, "", 0.0, REC|STR|DONTFREE };

-static Cell dollar1 = { OCELL, CFLD, nil, "", 0.0, FLD|STR|DONTFREE };

+static Cell dollar0 = { OCELL, CFLD, nil, EMPTY, 0.0, REC|STR|DONTFREE };

+static Cell dollar1 = { OCELL, CFLD, nil, EMPTY, 0.0, FLD|STR|DONTFREE };

 void recinit(unsigned int n)

@@ -194,7 +194,7 @@

 	extern Array *ARGVtab;

 	sprint(temp, "%d", n);

-	x = setsymtab(temp, "", 0.0, STR, ARGVtab);

+	x = setsymtab(temp, EMPTY, 0.0, STR, ARGVtab);

 	s = getsval(x);

 	dprint( ("getargv(%d) returns |%s|\n", n, s) );

 	return s;

@@ -322,7 +322,7 @@

 		p = fldtab[i];

 		if (freeable(p))

 			xfree(p->sval);

-		p->sval = "";

+		p->sval = EMPTY;

 		p->tval = FLD | STR | DONTFREE;

--- a/parse.c

+++ b/parse.c

@@ -166,7 +166,8 @@

 		if (isfcn(cp))

 			SYNTAX( "%s is a function, not an array", cp->nval );

 		else if (!isarr(cp)) {

-			xfree(cp->sval);

+			if (freeable(cp))

+				xfree(cp->sval);

 			cp->sval = (char *) makesymtab(NSYMTAB);

 			cp->tval = ARR;

--- a/run.c

+++ b/run.c

@@ -28,7 +28,7 @@

 Cell	*jexit	= &exitcell;

 static Cell	retcell		={ OJUMP, JRET, 0, 0, 0.0, NUM };

 Cell	*jret	= &retcell;

-static Cell	tempcell	={ OCELL, CTEMP, 0, "", 0.0, NUM|STR|DONTFREE };

+static Cell	tempcell	={ OCELL, CTEMP, 0, EMPTY, 0.0, NUM|STR|DONTFREE };

 Node	*curnode = nil;	/* the node being executed, for debugging */

@@ -200,7 +200,7 @@

 Cell *call(Node **a, int)	/* function call.  very kludgy and fragile */

-	static Cell newcopycell = { OCELL, CCOPY, 0, "", 0.0, NUM|STR|DONTFREE };

+	static Cell newcopycell = { OCELL, CCOPY, 0, EMPTY, 0.0, NUM|STR|DONTFREE };

 	int i, ncall, ndef;

 	Node *x;

 	Cell *args[NARGS], *oargs[NARGS];	/* BUG: fixed size arrays */

@@ -304,10 +304,11 @@

 	y = gettemp();

 	y->csub = CCOPY;	/* prevents freeing until call is over */

 	y->nval = x->nval;	/* BUG? */

-	y->sval = x->sval ? tostring(x->sval) : nil;

+	y->sval = x->sval != nil && x->sval != EMPTY ? tostring(x->sval) : EMPTY;

 	y->fval = x->fval;

 	y->tval = x->tval & ~(CON|FLD|REC|DONTFREE);	/* copy is not constant or field */

-							/* is DONTFREE right? */

+	if (y->sval == EMPTY)

+		y->tval |= DONTFREE;

 	return y;

@@ -466,7 +467,7 @@

 		x->tval |= ARR;

 		x->sval = (char *) makesymtab(NSYMTAB);

-	z = setsymtab(buf, "", 0.0, STR|NUM, (Array *) x->sval);

+	z = setsymtab(buf, EMPTY, 0.0, STR|NUM, (Array *) x->sval);

 	z->ctype = OCELL;

 	z->csub = CVAR;

 	if (istemp(x))

@@ -747,7 +748,7 @@

 				tfree(z);

 		x = gettemp();

-		setsval(x, "");

+		setsval(x, EMPTY);

 		return(x);

 	m = (int) getfval(y);

@@ -1289,7 +1290,7 @@

 				if (t[-1] == 0 || *t == 0) {

 					n++;

 					sprint(num, "%d", n);

-					setsymtab(num, "", 0.0, STR, (Array *) ap->sval);

+					setsymtab(num, EMPTY, 0.0, STR, (Array *) ap->sval);

 					goto spdone;

 			} while (nematch(p,s,t));

--- a/tran.c

+++ b/tran.c

@@ -8,6 +8,8 @@

 #define	FULLTAB	2	/* rehash when table gets this x full */

 #define	GROWTAB 4	/* grow table by this factor */

+char	EMPTY[] = {'\0'};

 Array	*symtab;	/* main symbol table */

 char	**FS;		/* initial field sep */

@@ -44,7 +46,7 @@

 	literal0 = setsymtab("0", "0", 0.0, NUM|STR|CON|DONTFREE, symtab);

 	/* this is used for if(x)... tests: */

-	nullloc = setsymtab("$zero&null", "", 0.0, NUM|STR|CON|DONTFREE, symtab);

+	nullloc = setsymtab("$zero&null", EMPTY, 0.0, NUM|STR|CON|DONTFREE, symtab);

 	nullnode = celltonode(nullloc, CCON);

 	FS = &setsymtab("FS", " ", 0.0, STR|DONTFREE, symtab)->sval;

@@ -53,19 +55,19 @@

 	ORS = &setsymtab("ORS", "\n", 0.0, STR|DONTFREE, symtab)->sval;

 	OFMT = &setsymtab("OFMT", "%.6g", 0.0, STR|DONTFREE, symtab)->sval;

 	CONVFMT = &setsymtab("CONVFMT", "%.6g", 0.0, STR|DONTFREE, symtab)->sval;

-	FILENAME = &setsymtab("FILENAME", "", 0.0, STR|DONTFREE, symtab)->sval;

-	nfloc = setsymtab("NF", "", 0.0, NUM, symtab);

+	FILENAME = &setsymtab("FILENAME", EMPTY, 0.0, STR|DONTFREE, symtab)->sval;

+	nfloc = setsymtab("NF", EMPTY, 0.0, NUM, symtab);

 	NF = &nfloc->fval;

-	nrloc = setsymtab("NR", "", 0.0, NUM, symtab);

+	nrloc = setsymtab("NR", EMPTY, 0.0, NUM, symtab);

 	NR = &nrloc->fval;

-	fnrloc = setsymtab("FNR", "", 0.0, NUM, symtab);

+	fnrloc = setsymtab("FNR", EMPTY, 0.0, NUM, symtab);

 	FNR = &fnrloc->fval;

 	SUBSEP = &setsymtab("SUBSEP", "\034", 0.0, STR|DONTFREE, symtab)->sval;

-	rstartloc = setsymtab("RSTART", "", 0.0, NUM, symtab);

+	rstartloc = setsymtab("RSTART", EMPTY, 0.0, NUM, symtab);

 	RSTART = &rstartloc->fval;

-	rlengthloc = setsymtab("RLENGTH", "", 0.0, NUM, symtab);

+	rlengthloc = setsymtab("RLENGTH", EMPTY, 0.0, NUM, symtab);

 	RLENGTH = &rlengthloc->fval;

-	symtabloc = setsymtab("SYMTAB", "", 0.0, ARR, symtab);

+	symtabloc = setsymtab("SYMTAB", EMPTY, 0.0, ARR, symtab);

 	symtabloc->sval = (char *) symtab;

@@ -76,8 +78,8 @@

 	char temp[50];

 	Awkfloat f;

-	AARGC = &setsymtab("ARGC", "", (Awkfloat) ac, NUM, symtab)->fval;

-	cp = setsymtab("ARGV", "", 0.0, ARR, symtab);

+	AARGC = &setsymtab("ARGC", EMPTY, (Awkfloat) ac, NUM, symtab)->fval;

+	cp = setsymtab("ARGV", EMPTY, 0.0, ARR, symtab);

 	ARGVtab = makesymtab(NSYMTAB);	/* could be (int) ARGC as well */

 	cp->sval = (char *) ARGVtab;

 	for (i = 0; i < ac; i++) {

@@ -205,8 +207,10 @@

 		p->sval = (char *) ENVtab;

 		p->tval = ARR;

 	} else {

-		p->sval = s ? tostring(s) : tostring("");

+		p->sval = s != nil && s != EMPTY ? tostring(s) : EMPTY;

 		p->tval = t;

+		if (p->sval == EMPTY)

+			p->tval |= DONTFREE;

 	p->csub = CUNK;

 	p->ctype = OCELL;

@@ -316,12 +320,15 @@

 		donefld = 0;	/* mark $1... invalid */

 		donerec = 1;

-	t = tostring(s);	/* in case it's self-assign */

+	t = s != nil && s != EMPTY ? tostring(s) : EMPTY;	/* in case it's self-assign */

 	vp->tval &= ~NUM;

 	vp->tval |= STR;

 	if (freeable(vp))

 		xfree(vp->sval);

-	vp->tval &= ~DONTFREE;

+	if (t != EMPTY)

+		vp->tval &= ~DONTFREE;

+	else

+		vp->tval |= DONTFREE;

 	   dprint( ("setsval %p: %s = \"%s (%p)\", t=%o\n", vp, vp->nval, t,t, vp->tval) );

 	return(vp->sval = t);

--

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