shithub: scc

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[cc1] Fix pcompare() with NULL operands

Pcompare() was using eqtype() to see if the type of the operands
were compatible, but this is an error because a null pointer
can be compared to any pointer. For this reason the correct
code must use convert() which currently deals with all the
possible combinations

--- a/cc1/expr.c

+++ b/cc1/expr.c

@@ -351,23 +351,16 @@

 static Node *

 pcompare(int op, Node *lp, Node *rp)

 {

-	Node *np;

-	int err = 0;

+	Node *np, *p;

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

 		XCHG(lp, rp, np);

+	else if (eqtype(lp->type, pvoidtype, 1))

+		XCHG(lp, rp, np);

-	if (rp->type->prop & TINTEGER) {

-		if (!cmpnode(rp, 0))

-			err = 1;

-		rp = convert(rp, pvoidtype, 1);

-	} else if (rp->type->op == PTR) {

-		if (!eqtype(lp->type, rp->type, 1))

-			err = 1;

-	} else {

-		err = 1;

-	}

-	if (err)

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

+		rp = p;

+	else

 		errorp("incompatible types in comparison");

 	return node(op, inttype, lp, rp);

 }

--- a/tests/execute/scc-tests.lst

+++ b/tests/execute/scc-tests.lst

@@ -105,3 +105,4 @@

 0112-cond.c

 0113-externredecl.c

 0114-shortassig.c

+0115-null-comparision.c