Strict mode eval/arguments LHS.

Review URL: http://codereview.chromium.org/6335013/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6503 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/messages.js

@@ -241,6 +241,9 @@ function FormatMessage(message) {
       strict_duplicate_property:    "Duplicate data property in object literal not allowed in strict mode",
       accessor_data_property:       "Object literal may not have data and accessor property with the same name",
       accessor_get_set:             "Object literal may not have multiple get/set accessors with the same name",
+      strict_lhs_eval_assignment:   "Assignment to eval or arguments is not allowed in strict mode",
+      strict_lhs_postfix:           "Postfix increment/decrement may not have eval or arguments operand in strict mode",
+      strict_lhs_prefix:            "Prefix increment/decrement may not have eval or arguments operand in strict mode",
     };
   }
   var format = kMessages[message.type];

src/parser.cc

@@ -2292,6 +2292,11 @@ Expression* Parser::ParseAssignmentExpression(bool accept_IN, bool* ok) {
     expression = NewThrowReferenceError(type);
   }
 
+  if (temp_scope_->StrictMode()) {
+    // Assignment to eval or arguments is disallowed in strict mode.
+    CheckStrictModeLValue(expression, "strict_lhs_assignment", CHECK_OK);
+  }
+
   Token::Value op = Next();  // Get assignment operator.
   int pos = scanner().location().beg_pos;
   Expression* right = ParseAssignmentExpression(accept_IN, CHECK_OK);
@@ -2518,6 +2523,12 @@ Expression* Parser::ParseUnaryExpression(bool* ok) {
       Handle<String> type = Factory::invalid_lhs_in_prefix_op_symbol();
       expression = NewThrowReferenceError(type);
     }
+
+    if (temp_scope_->StrictMode()) {
+      // Prefix expression operand in strict mode may not be eval or arguments.
+      CheckStrictModeLValue(expression, "strict_lhs_prefix", CHECK_OK);
+    }
+
     int position = scanner().location().beg_pos;
     IncrementOperation* increment = new IncrementOperation(op, expression);
     return new CountOperation(true /* prefix */, increment, position);
@@ -2543,6 +2554,12 @@ Expression* Parser::ParsePostfixExpression(bool* ok) {
       Handle<String> type = Factory::invalid_lhs_in_postfix_op_symbol();
       expression = NewThrowReferenceError(type);
     }
+
+    if (temp_scope_->StrictMode()) {
+      // Postfix expression operand in strict mode may not be eval or arguments.
+      CheckStrictModeLValue(expression, "strict_lhs_prefix", CHECK_OK);
+    }
+
     Token::Value next = Next();
     int position = scanner().location().beg_pos;
     IncrementOperation* increment = new IncrementOperation(next, expression);
@@ -3692,6 +3709,24 @@ Handle<String> Parser::ParseIdentifierName(bool* ok) {
   return GetSymbol(ok);
 }
 
+
+// Checks LHS expression for assignment and prefix/postfix increment/decrement
+// in strict mode.
+void Parser::CheckStrictModeLValue(Expression* expression,
+                                   const char* error,
+                                   bool* ok) {
+  ASSERT(temp_scope_->StrictMode());
+  VariableProxy* lhs = expression != NULL
+      ? expression->AsVariableProxy()
+      : NULL;
+
+  if (lhs != NULL && !lhs->is_this() && IsEvalOrArguments(lhs->name())) {
+    ReportMessage(error, Vector<const char*>::empty());
+    *ok = false;
+  }
+}
+
+
 // Checks whether octal literal last seen is between beg_pos and end_pos.
 // If so, reports an error.
 void Parser::CheckOctalLiteral(int beg_pos, int end_pos, bool* ok) {

src/parser.h

@@ -613,6 +613,11 @@ class Parser {
                                            bool* is_set,
                                            bool* ok);
 
+  // Strict mode validation of LValue expressions
+  void CheckStrictModeLValue(Expression* expression,
+                             const char* error,
+                             bool* ok);
+
   // Strict mode octal literal validation.
   void CheckOctalLiteral(int beg_pos, int end_pos, bool* ok);
 

test/mjsunit/strict-mode.js

@@ -203,3 +203,65 @@ assertThrows("var x = { 'foo': 'data', get foo() { } };", SyntaxError)
 assertThrows("var x = { get 'foo'() { }, 'foo': 'data' };", SyntaxError)
 assertThrows("var x = { '12': 1, get '12'(){}};", SyntaxError);
 assertThrows("var x = { '12': 1, get 12(){}};", SyntaxError);
+
+// Assignment to eval or arguments
+CheckStrictMode("function strict() { eval = undefined; }", SyntaxError)
+CheckStrictMode("function strict() { arguments = undefined; }", SyntaxError)
+CheckStrictMode("function strict() { print(eval = undefined); }", SyntaxError)
+CheckStrictMode("function strict() { print(arguments = undefined); }", SyntaxError)
+CheckStrictMode("function strict() { var x = eval = undefined; }", SyntaxError)
+CheckStrictMode("function strict() { var x = arguments = undefined; }", SyntaxError)
+
+// Compound assignment to eval or arguments
+CheckStrictMode("function strict() { eval *= undefined; }", SyntaxError)
+CheckStrictMode("function strict() { arguments /= undefined; }", SyntaxError)
+CheckStrictMode("function strict() { print(eval %= undefined); }", SyntaxError)
+CheckStrictMode("function strict() { print(arguments %= undefined); }", SyntaxError)
+CheckStrictMode("function strict() { var x = eval += undefined; }", SyntaxError)
+CheckStrictMode("function strict() { var x = arguments -= undefined; }", SyntaxError)
+CheckStrictMode("function strict() { eval <<= undefined; }", SyntaxError)
+CheckStrictMode("function strict() { arguments >>= undefined; }", SyntaxError)
+CheckStrictMode("function strict() { print(eval >>>= undefined); }", SyntaxError)
+CheckStrictMode("function strict() { print(arguments &= undefined); }", SyntaxError)
+CheckStrictMode("function strict() { var x = eval ^= undefined; }", SyntaxError)
+CheckStrictMode("function strict() { var x = arguments |= undefined; }", SyntaxError)
+
+// Postfix increment with eval or arguments
+CheckStrictMode("function strict() { eval++; }", SyntaxError)
+CheckStrictMode("function strict() { arguments++; }", SyntaxError)
+CheckStrictMode("function strict() { print(eval++); }", SyntaxError)
+CheckStrictMode("function strict() { print(arguments++); }", SyntaxError)
+CheckStrictMode("function strict() { var x = eval++; }", SyntaxError)
+CheckStrictMode("function strict() { var x = arguments++; }", SyntaxError)
+
+// Postfix decrement with eval or arguments
+CheckStrictMode("function strict() { eval--; }", SyntaxError)
+CheckStrictMode("function strict() { arguments--; }", SyntaxError)
+CheckStrictMode("function strict() { print(eval--); }", SyntaxError)
+CheckStrictMode("function strict() { print(arguments--); }", SyntaxError)
+CheckStrictMode("function strict() { var x = eval--; }", SyntaxError)
+CheckStrictMode("function strict() { var x = arguments--; }", SyntaxError)
+
+// Prefix increment with eval or arguments
+CheckStrictMode("function strict() { ++eval; }", SyntaxError)
+CheckStrictMode("function strict() { ++arguments; }", SyntaxError)
+CheckStrictMode("function strict() { print(++eval); }", SyntaxError)
+CheckStrictMode("function strict() { print(++arguments); }", SyntaxError)
+CheckStrictMode("function strict() { var x = ++eval; }", SyntaxError)
+CheckStrictMode("function strict() { var x = ++arguments; }", SyntaxError)
+
+// Prefix decrement with eval or arguments
+CheckStrictMode("function strict() { --eval; }", SyntaxError)
+CheckStrictMode("function strict() { --arguments; }", SyntaxError)
+CheckStrictMode("function strict() { print(--eval); }", SyntaxError)
+CheckStrictMode("function strict() { print(--arguments); }", SyntaxError)
+CheckStrictMode("function strict() { var x = --eval; }", SyntaxError)
+CheckStrictMode("function strict() { var x = --arguments; }", SyntaxError)
+
+// Prefix unary operators other than delete, ++, -- are valid in strict mode
+function StrictModeUnaryOperators() {
+  "use strict";
+  var x = [void eval, typeof eval, +eval, -eval, ~eval, !eval];
+  var y = [void arguments, typeof arguments,
+           +arguments, -arguments, ~arguments, !arguments];
+}
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