[njs] Comprehensive test of "return" statement location.

[Igor Sysoev]

details:   http://hg.nginx.org/njs/rev/6cc16ad934a4
branches:  
changeset: 301:6cc16ad934a4
user:      Igor Sysoev <igor at sysoev.ru>
date:      Mon Jan 16 17:32:10 2017 +0300
description:
Comprehensive test of "return" statement location.

Found with afl-fuzz.

diffstat:

 njs/njs_parser.c         |  22 ++++++++++++++--------
 njs/test/njs_unit_test.c |   3 +++
 2 files changed, 17 insertions(+), 8 deletions(-)

diffs (45 lines):

diff -r 07dc20c1206d -r 6cc16ad934a4 njs/njs_parser.c
--- a/njs/njs_parser.c	Mon Jan 16 14:51:29 2017 +0300
+++ b/njs/njs_parser.c	Mon Jan 16 17:32:10 2017 +0300
@@ -697,14 +697,20 @@ njs_parser_function_lambda(njs_vm_t *vm,
 static njs_token_t
 njs_parser_return_statement(njs_vm_t *vm, njs_parser_t *parser)
 {
-    njs_token_t        token;
-    njs_parser_node_t  *node;
-
-    if (parser->scope->type == NJS_SCOPE_GLOBAL) {
-        nxt_alert(&vm->trace, NXT_LEVEL_ERROR,
-                  "SyntaxError: Illegal return statement");
-
-        return NXT_ERROR;
+    njs_token_t         token;
+    njs_parser_node_t   *node;
+    njs_parser_scope_t  *scope;
+
+    for (scope = parser->scope;
+         scope->type != NJS_SCOPE_FUNCTION;
+         scope = scope->parent)
+    {
+        if (scope->type == NJS_SCOPE_GLOBAL) {
+            nxt_alert(&vm->trace, NXT_LEVEL_ERROR,
+                      "SyntaxError: Illegal return statement");
+
+            return NXT_ERROR;
+        }
     }
 
     node = njs_parser_node_alloc(vm);
diff -r 07dc20c1206d -r 6cc16ad934a4 njs/test/njs_unit_test.c
--- a/njs/test/njs_unit_test.c	Mon Jan 16 14:51:29 2017 +0300
+++ b/njs/test/njs_unit_test.c	Mon Jan 16 17:32:10 2017 +0300
@@ -3976,6 +3976,9 @@ static njs_unit_test_t  njs_test[] =
     { nxt_string("return"),
       nxt_string("SyntaxError: Illegal return statement in 1") },
 
+    { nxt_string("{return}"),
+      nxt_string("SyntaxError: Illegal return statement in 1") },
+
     { nxt_string("function f() { return f() } f()"),
       nxt_string("RangeError: Maximum call stack size exceeded") },