compile: make SyntaxError on return outside function

Author: ncw

compile/compile.go

@@ -967,6 +967,9 @@ func (c *compiler) Stmt(stmt ast.Stmt) {
 		c.class(stmt, node)
 	case *ast.Return:
 		// Value Expr
+		if c.SymTable.Type != symtable.FunctionBlock {
+			panic(py.ExceptionNewf(py.SyntaxError, "'return' outside function"))
+		}
 		if node.Value != nil {
 			c.Expr(node.Value)
 		} else {

compile/compile_data_test.go

@@ -2254,6 +2254,7 @@ var compileTestData = []struct {
 		Firstlineno:    1,
 		Lnotab:         "",
 	}, nil, ""},
+	{"return", "exec", nil, py.SyntaxError, "'return' outside function"},
 	{"def fn(): pass", "exec", &py.Code{
 		Argcount:       0,
 		Kwonlyargcount: 0,

compile/make_compile_test.py

@@ -176,6 +176,8 @@ def nested(d):
     ('''f(a, b, *args)''', "eval"),
     ('''f(a, b, *args, d=e, **kwargs)''', "eval"),
     ('''f(a, d=e, **kwargs)''', "eval"),
+    # return
+    ('''return''', "exec", SyntaxError),
     # def
     ('''def fn(): pass''', "exec"),
     ('''def fn(a): pass''', "exec"),