Support assignment expressions in the pre-scanner. (#3382)

Fixes #3355.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/parser/js/js-scanner.c

@@ -64,6 +64,9 @@ typedef enum
   SCAN_STACK_FUNCTION_STATEMENT,           /**< function statement */
   SCAN_STACK_FUNCTION_EXPRESSION,          /**< function expression */
   SCAN_STACK_FUNCTION_PROPERTY,            /**< function expression in an object literal or class */
+#if ENABLED (JERRY_ES2015)
+  SCAN_STACK_FUNCTION_ARROW,               /**< arrow function expression */
+#endif /* ENABLED (JERRY_ES2015) */
   SCAN_STACK_SWITCH_BLOCK,                 /**< block part of "switch" statement */
   SCAN_STACK_IF_STATEMENT,                 /**< statement part of "if" statements */
   SCAN_STACK_WITH_STATEMENT,               /**< statement part of "with" statements */
@@ -162,7 +165,7 @@ scanner_check_arrow_body (parser_context_t *context_p, /**< context */
 
   lexer_next_token (context_p);
   scanner_context_p->mode = SCAN_MODE_STATEMENT_OR_TERMINATOR;
-  parser_stack_push_uint8 (context_p, SCAN_STACK_FUNCTION_EXPRESSION);
+  parser_stack_push_uint8 (context_p, SCAN_STACK_FUNCTION_ARROW);
 } /* scanner_check_arrow_body */
 
 /**
@@ -674,7 +677,8 @@ scanner_scan_primary_expression (parser_context_t *context_p, /**< context */
 static bool
 scanner_scan_post_primary_expression (parser_context_t *context_p, /**< context */
                                       scanner_context_t *scanner_context_p, /**< scanner context */
-                                      lexer_token_type_t type) /**< current token type */
+                                      lexer_token_type_t type, /**< current token type */
+                                      scan_stack_modes_t stack_top) /**< current stack top */
 {
   switch (type)
   {
@@ -705,12 +709,13 @@ scanner_scan_post_primary_expression (parser_context_t *context_p, /**< context
     case LEXER_INCREASE:
     case LEXER_DECREASE:
     {
-      if (!(context_p->token.flags & LEXER_WAS_NEWLINE))
+      return !(context_p->token.flags & LEXER_WAS_NEWLINE);
-      {
+    }
-        scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION_END;
+    case LEXER_QUESTION_MARK:
-        return true;
+    {
-      }
+      parser_stack_push_uint8 (context_p, SCAN_STACK_COLON_EXPRESSION);
-      /* FALLTHRU */
+      scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION;
+      return true;
     }
     default:
     {
@@ -718,6 +723,13 @@ scanner_scan_post_primary_expression (parser_context_t *context_p, /**< context
     }
   }
 
+  if (LEXER_IS_BINARY_OP_TOKEN (type)
+      && (type != LEXER_KEYW_IN || !SCANNER_IS_FOR_START (stack_top)))
+  {
+    scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION;
+    return true;
+  }
+
   return false;
 } /* scanner_scan_post_primary_expression */
 
@@ -732,95 +744,74 @@ scanner_scan_primary_expression_end (parser_context_t *context_p, /**< context *
                                      lexer_token_type_t type, /**< current token type */
                                      scan_stack_modes_t stack_top) /**< current stack top */
 {
-  switch (type)
+  if (type == LEXER_COMMA)
   {
-    case LEXER_QUESTION_MARK:
+    switch (stack_top)
     {
-      parser_stack_push_uint8 (context_p, SCAN_STACK_COLON_EXPRESSION);
+      case SCAN_STACK_VAR:
-      scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION;
+#if ENABLED (JERRY_ES2015)
-      return SCAN_NEXT_TOKEN;
+      case SCAN_STACK_LET:
-    }
+      case SCAN_STACK_CONST:
-    case LEXER_COMMA:
+#endif /* ENABLED (JERRY_ES2015) */
-    {
+      case SCAN_STACK_FOR_VAR_START:
-      switch (stack_top)
+#if ENABLED (JERRY_ES2015)
+      case SCAN_STACK_FOR_LET_START:
+      case SCAN_STACK_FOR_CONST_START:
+#endif /* ENABLED (JERRY_ES2015) */
       {
-        case SCAN_STACK_VAR:
+        scanner_context_p->mode = SCAN_MODE_VAR_STATEMENT;
-#if ENABLED (JERRY_ES2015)
+        return SCAN_NEXT_TOKEN;
-        case SCAN_STACK_LET:
-        case SCAN_STACK_CONST:
-#endif /* ENABLED (JERRY_ES2015) */
-        case SCAN_STACK_FOR_VAR_START:
-#if ENABLED (JERRY_ES2015)
-        case SCAN_STACK_FOR_LET_START:
-        case SCAN_STACK_FOR_CONST_START:
-#endif /* ENABLED (JERRY_ES2015) */
-        {
-          scanner_context_p->mode = SCAN_MODE_VAR_STATEMENT;
-          return SCAN_NEXT_TOKEN;
-        }
-        case SCAN_STACK_COLON_EXPRESSION:
-        {
-          scanner_raise_error (context_p);
-          break;
-        }
-#if ENABLED (JERRY_ES2015)
-        case SCAN_STACK_BINDING_INIT:
-        case SCAN_STACK_BINDING_LIST_INIT:
-        {
-          break;
-        }
-        case SCAN_STACK_ARROW_ARGUMENTS:
-        {
-          lexer_next_token (context_p);
-          scanner_process_arrow_arg (context_p, scanner_context_p);
-          return SCAN_KEEP_TOKEN;
-        }
-        case SCAN_STACK_ARROW_EXPRESSION:
-        {
-          break;
-        }
-        case SCAN_STACK_FUNCTION_PARAMETERS:
-        {
-          scanner_context_p->mode = SCAN_MODE_CONTINUE_FUNCTION_ARGUMENTS;
-          parser_stack_pop_uint8 (context_p);
-          return SCAN_NEXT_TOKEN;
-        }
-        case SCAN_STACK_ARRAY_LITERAL:
-        {
-          scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION;
-
-          if (scanner_context_p->binding_type != SCANNER_BINDING_NONE)
-          {
-            scanner_context_p->mode = SCAN_MODE_BINDING;
-          }
-
-          return SCAN_NEXT_TOKEN;
-        }
-#endif /* ENABLED (JERRY_ES2015) */
-        case SCAN_STACK_OBJECT_LITERAL:
-        {
-          scanner_context_p->mode = SCAN_MODE_PROPERTY_NAME;
-          return SCAN_KEEP_TOKEN;
-        }
-        default:
-        {
-          scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION;
-          return SCAN_NEXT_TOKEN;
-        }
       }
-      break;
+      case SCAN_STACK_COLON_EXPRESSION:
-    }
+      {
-    default:
+        scanner_raise_error (context_p);
-    {
+        break;
-      break;
+      }
-    }
+#if ENABLED (JERRY_ES2015)
-  }
+      case SCAN_STACK_BINDING_INIT:
+      case SCAN_STACK_BINDING_LIST_INIT:
+      {
+        break;
+      }
+      case SCAN_STACK_ARROW_ARGUMENTS:
+      {
+        lexer_next_token (context_p);
+        scanner_process_arrow_arg (context_p, scanner_context_p);
+        return SCAN_KEEP_TOKEN;
+      }
+      case SCAN_STACK_ARROW_EXPRESSION:
+      {
+        break;
+      }
+      case SCAN_STACK_FUNCTION_PARAMETERS:
+      {
+        scanner_context_p->mode = SCAN_MODE_CONTINUE_FUNCTION_ARGUMENTS;
+        parser_stack_pop_uint8 (context_p);
+        return SCAN_NEXT_TOKEN;
+      }
+      case SCAN_STACK_ARRAY_LITERAL:
+      {
+        scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION;
 
-  if (LEXER_IS_BINARY_OP_TOKEN (type)
+        if (scanner_context_p->binding_type != SCANNER_BINDING_NONE)
-      && (type != LEXER_KEYW_IN || !SCANNER_IS_FOR_START (stack_top)))
+        {
-  {
+          scanner_context_p->mode = SCAN_MODE_BINDING;
-    scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION;
+        }
-    return SCAN_NEXT_TOKEN;
+
+        return SCAN_NEXT_TOKEN;
+      }
+#endif /* ENABLED (JERRY_ES2015) */
+      case SCAN_STACK_OBJECT_LITERAL:
+      {
+        scanner_context_p->mode = SCAN_MODE_PROPERTY_NAME;
+        return SCAN_KEEP_TOKEN;
+      }
+      default:
+      {
+        scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION;
+        return SCAN_NEXT_TOKEN;
+      }
+    }
   }
 
   switch (stack_top)
@@ -2203,15 +2194,24 @@ scanner_scan_statement_end (parser_context_t *context_p, /**< context */
         continue;
       }
       case SCAN_STACK_FUNCTION_EXPRESSION:
+#if ENABLED (JERRY_ES2015)
+      case SCAN_STACK_FUNCTION_ARROW:
+#endif /* ENABLED (JERRY_ES2015) */
       {
         if (type != LEXER_RIGHT_BRACE)
         {
           break;
         }
 
-        scanner_pop_literal_pool (context_p, scanner_context_p);
-
         scanner_context_p->mode = SCAN_MODE_POST_PRIMARY_EXPRESSION;
+#if ENABLED (JERRY_ES2015)
+        if (context_p->stack_top_uint8 == SCAN_STACK_FUNCTION_ARROW)
+        {
+          scanner_context_p->mode = SCAN_MODE_PRIMARY_EXPRESSION_END;
+        }
+#endif /* ENABLED (JERRY_ES2015) */
+
+        scanner_pop_literal_pool (context_p, scanner_context_p);
         parser_stack_pop_uint8 (context_p);
         return SCAN_NEXT_TOKEN;
       }
@@ -2634,7 +2634,7 @@ scanner_scan_all (parser_context_t *context_p, /**< context */
 #endif /* ENABLED (JERRY_ES2015) */
         case SCAN_MODE_POST_PRIMARY_EXPRESSION:
         {
-          if (scanner_scan_post_primary_expression (context_p, &scanner_context, type))
+          if (scanner_scan_post_primary_expression (context_p, &scanner_context, type, stack_top))
           {
             break;
           }

tests/jerry/es2015/arrow-assignment.js

@@ -0,0 +1,46 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+var y = 0
+var prot = Object.getPrototypeOf(/ /)
+
+prot.setY = function (v) { y = v }
+
+assert(y === 0)
+// Since arrow function is an assignment expression, this affects certain constructs
+var f = x => {}
+/ /.setY(5)
+assert(y === 5)
+
+var s
+// This is not a function call
+assert(eval("s = x => { return 1 }\n(3)") === 3)
+assert(typeof s === "function")
+
+// This is a function call
+assert(eval("s = function () { return 1 }\n(3)") === 1)
+assert(s === 1)
+
+var f = 5 ? x => 1 : x => 2
+assert(f() === 1)
+
+var f = [x => 2][0]
+assert(f() === 2)
+
+var f = 123; f += x => y
+assert(typeof f === "string")
+
+// Comma operator
+assert(eval("x => {}, 5") === 5)

tests/jerry/es2015/arrow-function.js

@@ -153,6 +153,7 @@ must_throw ("x => {} (4)");
 must_throw ("!x => 4");
 must_throw ("x => {} = 1");
 must_throw ("x => {} a = 1");
+must_throw ("x => {} ? 1 : 0");
 must_throw_strict ("(package) => 0");
 must_throw_strict ("(package) => { return 5 }");
 must_throw_strict ("(x,x,x) => 0");
@@ -181,21 +182,3 @@ assert(f()()() === 7);
 
 var f = (((a=1,b=2) => ((x => (((a) => 8))))));
 assert(f()()() === 8);
-
-var s;
-// This is not a function call
-assert(eval("s = x => { return 1 }\n(3)") === 3);
-assert(typeof s === "function")
-
-// This is a function call
-assert(eval("s = function () { return 1 }\n(3)") === 1);
-assert(s === 1)
-
-var f = 5 ? x => 1 : x => 2
-assert(f() === 1)
-
-var f = [x => 2][0]
-assert(f() === 2)
-
-var f = 123; f += x => y;
-assert(typeof f === "string");

tests/jerry/es2015/regression-test-issue-3355.js

@@ -0,0 +1,16 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+var $ = $ => { }
+/ /