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[cc1] Call decay() in postfix()

Calling decay() in postfix avoids calling it across a lot of different functions
in expr.c, but it has the problem that it makes a bit harder don't decay in the case
of sizeof. This patch is a good compromise between them, because it adds a parameter
to unary() and postfix() and callers set it to the correct value to avoid decaying.

--- a/cc1/expr.c

+++ b/cc1/expr.c

@@ -144,9 +144,6 @@

 static Node *

 chkternary(Node *yes, Node *no)

 {

-	yes = decay(yes);

-	no = decay(no);

-

 	/*

 	 * FIXME:

 	 * We are ignoring type qualifiers here,

@@ -386,9 +383,6 @@

 {

 	Type *ltp, *rtp;

-	lp = decay(lp);

-	rp = decay(rp);

-

 	ltp = lp->type;

 	rtp = rp->type;

@@ -438,7 +432,6 @@

 static Node *

 exp2cond(Node *np, char neg)

 {

-	np = decay(np);

 	if (np->type->prop & TAGGREG) {

 		errorp("used struct/union type value where scalar is required");

 		np = constnode(zero);

@@ -491,7 +484,6 @@

 static Node *

 content(char op, Node *np)

 {

-	np = decay(np);

 	switch (BTYPE(np)) {

 	case ARY:

 	case FTN:

@@ -519,7 +511,7 @@

 	if (!(lp->type->prop & TINTEGER) && !(rp->type->prop & TINTEGER))

 		error("array subscript is not an integer");

-	np = arithmetic(OADD, decay(lp), decay(rp));

+	np = arithmetic(OADD, lp, rp);

 	tp = np->type;

 	if (tp->op != PTR)

 		errorp("subscripted value is neither array nor pointer");

@@ -529,7 +521,7 @@

 static Node *

 assignop(char op, Node *lp, Node *rp)

 {

-	if ((rp = convert(decay(rp), lp->type, 0)) == NULL) {

+	if ((rp = convert(rp, lp->type, 0)) == NULL) {

 		errorp("incompatible types when assigning");

 		return lp;

 	}

@@ -563,17 +555,22 @@

 static Node *

 address(char op, Node *np)

 {

-	Node *new;

+	Node *new, *left;

-	if (BTYPE(np) != FTN) {

-		chklvalue(np);

-		if (np->sym && (np->sym->flags & SREGISTER))

-			errorp("address of register variable '%s' requested", yytext);

-		if (np->op == OPTR) {

-			Node *new = np->left;

-			free(np);

-			return new;

-		}

+	/*

+	 * ansi c accepts & applied to a function name, and it generates

+	 * a function pointer

+	 */

+	left = np->left;

+	if (np->op == OADDR && left->sym && left->type->op == FTN)

+		return np;

+	chklvalue(np);

+	if (np->sym && (np->sym->flags & SREGISTER))

+		errorp("address of register variable '%s' requested", yytext);

+	if (np->op == OPTR) {

+		Node *new = np->left;

+		free(np);

+		return new;

 	}

 	new = node(op, mktype(np->type, PTR, 0, NULL), np, NULL);

@@ -585,7 +582,6 @@

 static Node *

 negation(char op, Node *np)

 {

-	np = decay(np);

 	if (!(np->type->prop & TARITH) && np->type->op != PTR) {

 		errorp("invalid argument of unary '!'");

 		freetree(np);

@@ -636,7 +632,7 @@

 		sym->flags |= SHASINIT;

 		emit(ODECL, sym);

 		emit(OINIT, np);

-		np = decay(varnode(sym));

+		np = varnode(sym);

 		next();

 		break;

 	case CONSTANT:

@@ -688,7 +684,7 @@

 	toomany = 0;

 	do {

-		arg = decay(assign());

+		arg = assign();

 		argtype = *targs;

 		if (argtype == ellipsistype) {

 			n = 0;

@@ -728,7 +724,7 @@

 }

 static Node *

-postfix(Node *lp)

+postfix(Node *lp, int issizeof)

 {

 	Node *rp;

@@ -735,6 +731,8 @@

 	if (!lp)

 		lp = primary();

 	for (;;) {

+		if (!issizeof)

+			lp = decay(lp);

 		switch (yytoken) {

 		case '[':

 			next();

@@ -762,7 +760,7 @@

 	}

 }

-static Node *unary(void);

+static Node *unary(int);

 static Type *

 typeof(Node *np)

@@ -788,7 +786,7 @@

 		tp = typename();

 		break;

 	default:

-		tp = typeof(unary());

+		tp = typeof(unary(1));

 		break;

 	}

 	expect(')');

@@ -798,7 +796,7 @@

 static Node *cast(void);

 static Node *

-unary(void)

+unary(int issizeof)

 {

 	Node *(*fun)(char, Node *);

 	char op;

@@ -807,7 +805,7 @@

 	switch (yytoken) {

 	case SIZEOF:

 		next();

-		tp = (yytoken == '(') ? sizeexp() : typeof(unary());

+		tp = (yytoken == '(') ? sizeexp() : typeof(unary(1));

 		if (!(tp->prop & TDEFINED))

 			errorp("sizeof applied to an incomplete type");

 		return sizeofnode(tp);

@@ -815,7 +813,7 @@

 	case DEC:

 		op = (yytoken == INC) ? OA_ADD : OA_SUB;

 		next();

-		return incdec(unary(), op);

+		return incdec(unary(issizeof), op);

 	case '!': op = 0;     fun = negation;     break;

 	case '+': op = OADD;  fun = numericaluop; break;

 	case '-': op = ONEG;  fun = numericaluop; break;

@@ -822,7 +820,7 @@

 	case '~': op = OCPL;  fun = integeruop;   break;

 	case '&': op = OADDR; fun = address;      break;

 	case '*': op = OPTR;  fun = content;      break;

-	default:  return postfix(NULL);

+	default:  return postfix(NULL, issizeof);

 	}

 	next();

@@ -837,7 +835,7 @@

 	static int nested;

 	if (!accept('('))

-		return unary();

+		return unary(0);

 	switch (yytoken) {

 	case TQUALIFIER:

@@ -866,7 +864,7 @@

 		rp = expr();

 		--nested;

 		expect(')');

-		rp = postfix(rp);

+		rp = postfix(rp, 0);

 		break;

 	}

--- a/cc1/tests/test001.c

+++ b/cc1/tests/test001.c

@@ -9,13 +9,13 @@

 G6	I	F	"main

 {

 \

-V8	K	#N13

-Y7	V8	"	(

+V9	K	#N13

+Y8	V9	"	(

 	#"hello world

 	#K0A

 	#K00

 )

-	X4	Y7	'P	pP	cI

+	X4	Y8	'P	pP	cI

 	h	#I0

 }

 */