Fix writing to out-of-bounds arrays writing element 0.

src/V3AstNodes.cpp

@@ -199,6 +199,68 @@ bool AstSenTree::hasCombo() {
     return false;
 }
 
+//======================================================================
+// Special walking tree inserters
+
+void AstNode::addBeforeStmt(AstNode* newp, AstNode*) {
+    if (!backp()) newp->v3fatalSrc("Can't find current statement to addBeforeStmt");
+    // Look up; virtual call will find where to put it
+    this->backp()->addBeforeStmt(newp, this);
+}
+void AstNode::addNextStmt(AstNode* newp, AstNode*) {
+    if (!backp()) newp->v3fatalSrc("Can't find current statement to addBeforeStmt");
+    // Look up; virtual call will find where to put it
+    this->backp()->addNextStmt(newp, this);
+}
+
+void AstNodeStmt::addBeforeStmt(AstNode* newp, AstNode*) {
+    // Insert newp before current node
+    this->addHereThisAsNext(newp);
+}
+void AstNodeStmt::addNextStmt(AstNode* newp, AstNode*) {
+    // Insert newp after current node
+    this->addNextHere(newp);
+}
+
+void AstWhile::addBeforeStmt(AstNode* newp, AstNode* belowp) {
+    // Special, as statements need to be put in different places
+    // Belowp is how we came to recurse up to this point
+    // Preconditions insert first just before themselves (the normal rule for other statement types)
+    if (belowp == precondsp()) {
+	// Must have been first statement in precondsp list, so newp is new first statement
+	belowp->addHereThisAsNext(newp);
+    } else if (belowp == condp()) {
+	// Goes before condition, IE in preconditions
+	addPrecondsp(newp);
+    } else if (belowp == bodysp()) {
+	// Was first statement in body, so new front
+	belowp->addHereThisAsNext(newp);
+    } else {
+	belowp->v3fatalSrc("Doesn't look like this was really under the while");
+    }
+}
+void AstWhile::addNextStmt(AstNode* newp, AstNode* belowp) {
+    // Special, as statements need to be put in different places
+    // Belowp is how we came to recurse up to this point
+    // Preconditions insert first just before themselves (the normal rule for other statement types)
+    if (belowp == precondsp()) {
+	// Next in precond list
+	belowp->addNextHere(newp);
+    } else if (belowp == condp()) {
+	// Becomes first statement in body, body may have been empty
+	if (bodysp()) {
+	    bodysp()->addHereThisAsNext(newp);
+	} else {
+	    addBodysp(newp);
+	}
+    } else if (belowp == bodysp()) {
+	// Next statement in body
+	belowp->addNextHere(newp);
+    } else {
+	belowp->v3fatalSrc("Doesn't look like this was really under the while");
+    }
+}
+
 //======================================================================
 // Per-type Debugging