Merge pull request #9 from gopherjs/fp2

More FP fixes

analysis/passes/jsobjectptr/jsobjectptr.go

@@ -32,10 +32,13 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		if !internal.Is_jsObject(pass, node) {
 			return true
 		}
-		parent := stack[len(stack)-2]
+		parent, ok := internal.AncestorN(stack, 1)
+		if !ok {
+			return true
+		}
 		switch pt := parent.(type) {
 		case *ast.StarExpr:
-			// Fall through
+			return true
 		case *ast.CallExpr:
 			fun, ok := pt.Fun.(*ast.Ident)
 			if !ok {

analysis/passes/jsobjectptr/testdata/src/jsobjectptr/jsobjectptr.go

@@ -22,6 +22,7 @@ var (
 	_ struct{ x js.Object }     // want "js.Object must always be a pointer"
 	_ = struct{ x js.Object }{} // want "js.Object must always be a pointer"
 	_ = new(js.Object)
+	_ *js.Object
 )
 
 func _(js.Object) {} // want "js.Object must always be a pointer"
@@ -33,5 +34,9 @@ func _() js.Object { // want "js.Object must always be a pointer"
 func _() {
 	var x any
 	_, _ = x.(js.Object) // want "js.Object must always be a pointer"
-	_ = x
+}
+
+func _() {
+	var x *js.Object
+	_ = *x // TODO: This should fail
 }

internal/jsobject.go

@@ -43,3 +43,13 @@ func Is_jsObject(pass *analysis.Pass, node ast.Node) bool {
 	}
 	return pkg.Path() == "github.com/gopherjs/gopherjs/js"
 }
+
+// AncestorN returns the nth ancestor from stack, and true, or nil and false if
+// it does not exist.
+func AncestorN(stack []ast.Node, n int) (ast.Node, bool) {
+	l := len(stack)
+	if n > l {
+		return nil, false
+	}
+	return stack[l-(n+1)], true
+}