Fix a bug in with and catch context allocation.

We were only looking one level up the scope chain to decide which
closure to use in the fresh context.  Instead, we should look to the
first non-catch scope.

R=vegorov@chromium.org
BUG=1528
TEST=regress-1528

Review URL: http://codereview.chromium.org/7309002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8523 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/full-codegen-arm.cc

@@ -4243,19 +4243,20 @@ void FullCodeGenerator::LoadContextField(Register dst, int context_index) {
 
 
 void FullCodeGenerator::PushFunctionArgumentForContextAllocation() {
-  if (scope()->is_global_scope()) {
+  Scope* declaration_scope = scope()->DeclarationScope();
+  if (declaration_scope->is_global_scope()) {
     // Contexts nested in the global context have a canonical empty function
     // as their closure, not the anonymous closure containing the global
     // code.  Pass a smi sentinel and let the runtime look up the empty
     // function.
     __ mov(ip, Operand(Smi::FromInt(0)));
-  } else if (scope()->is_eval_scope()) {
+  } else if (declaration_scope->is_eval_scope()) {
     // Contexts created by a call to eval have the same closure as the
     // context calling eval, not the anonymous closure containing the eval
     // code.  Fetch it from the context.
     __ ldr(ip, ContextOperand(cp, Context::CLOSURE_INDEX));
   } else {
-    ASSERT(scope()->is_function_scope() || scope()->is_catch_scope());
+    ASSERT(declaration_scope->is_function_scope());
     __ ldr(ip, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   }
   __ push(ip);

src/ia32/full-codegen-ia32.cc

@@ -4202,19 +4202,20 @@ void FullCodeGenerator::LoadContextField(Register dst, int context_index) {
 
 
 void FullCodeGenerator::PushFunctionArgumentForContextAllocation() {
-  if (scope()->is_global_scope()) {
+  Scope* declaration_scope = scope()->DeclarationScope();
+  if (declaration_scope->is_global_scope()) {
     // Contexts nested in the global context have a canonical empty function
     // as their closure, not the anonymous closure containing the global
     // code.  Pass a smi sentinel and let the runtime look up the empty
     // function.
     __ push(Immediate(Smi::FromInt(0)));
-  } else if (scope()->is_eval_scope()) {
-    // Contexts created by a call to eval have the same closure as the
-    // context calling eval, not the anonymous closure containing the eval
-    // code.  Fetch it from the context.
+  } else if (declaration_scope->is_eval_scope()) {
+    // Contexts nested inside eval code have the same closure as the context
+    // calling eval, not the anonymous closure containing the eval code.
+    // Fetch it from the context.
     __ push(ContextOperand(esi, Context::CLOSURE_INDEX));
   } else {
-    ASSERT(scope()->is_function_scope() || scope()->is_catch_scope());
+    ASSERT(declaration_scope->is_function_scope());
     __ push(Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
   }
 }

src/mips/full-codegen-mips.cc

@@ -4262,19 +4262,20 @@ void FullCodeGenerator::LoadContextField(Register dst, int context_index) {
 
 
 void FullCodeGenerator::PushFunctionArgumentForContextAllocation() {
-  if (scope()->is_global_scope()) {
+  Scope* declaration_scope = scope()->DeclarationScope();
+  if (declaration_scope->is_global_scope()) {
     // Contexts nested in the global context have a canonical empty function
     // as their closure, not the anonymous closure containing the global
     // code.  Pass a smi sentinel and let the runtime look up the empty
     // function.
     __ li(at, Operand(Smi::FromInt(0)));
-  } else if (scope()->is_eval_scope()) {
+  } else if (declaration_scope->is_eval_scope()) {
     // Contexts created by a call to eval have the same closure as the
     // context calling eval, not the anonymous closure containing the eval
     // code.  Fetch it from the context.
     __ lw(at, ContextOperand(cp, Context::CLOSURE_INDEX));
   } else {
-    ASSERT(scope()->is_function_scope() || scope()->is_catch_scope());
+    ASSERT(declaration_scope->is_function_scope());
     __ lw(at, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   }
   __ push(at);

src/parser.cc

@@ -412,14 +412,6 @@ Scope* Parser::NewScope(Scope* parent, Scope::Type type, bool inside_with) {
 }
 
 
-Scope* Parser::DeclarationScope() {
-  Scope* scope = top_scope_;
-  while (scope->is_catch_scope()) {
-    scope = scope->outer_scope();
-  }
-  return scope;
-}
-
 // ----------------------------------------------------------------------------
 // Target is a support class to facilitate manipulation of the
 // Parser's target_stack_ (the stack of potential 'break' and
@@ -1310,7 +1302,7 @@ VariableProxy* Parser::Declare(Handle<String> name,
   // to the calling function context.
   // Similarly, strict mode eval scope does not leak variable declarations to
   // the caller's scope so we declare all locals, too.
-  Scope* declaration_scope = DeclarationScope();
+  Scope* declaration_scope = top_scope_->DeclarationScope();
   if (declaration_scope->is_function_scope() ||
       declaration_scope->is_strict_mode_eval_scope()) {
     // Declare the variable in the function scope.
@@ -1421,7 +1413,7 @@ Statement* Parser::ParseNativeDeclaration(bool* ok) {
   // isn't lazily compiled. The extension structures are only
   // accessible while parsing the first time not when reparsing
   // because of lazy compilation.
-  DeclarationScope()->ForceEagerCompilation();
+  top_scope_->DeclarationScope()->ForceEagerCompilation();
 
   // Compute the function template for the native function.
   v8::Handle<v8::FunctionTemplate> fun_template =
@@ -1525,7 +1517,7 @@ Block* Parser::ParseVariableDeclarations(bool accept_IN,
 
   Variable::Mode mode = Variable::VAR;
   bool is_const = false;
-  Scope* declaration_scope = DeclarationScope();
+  Scope* declaration_scope = top_scope_->DeclarationScope();
   if (peek() == Token::VAR) {
     Consume(Token::VAR);
   } else if (peek() == Token::CONST) {
@@ -1915,7 +1907,7 @@ Statement* Parser::ParseReturnStatement(bool* ok) {
   // function. See ECMA-262, section 12.9, page 67.
   //
   // To be consistent with KJS we report the syntax error at runtime.
-  Scope* declaration_scope = DeclarationScope();
+  Scope* declaration_scope = top_scope_->DeclarationScope();
   if (declaration_scope->is_global_scope() ||
       declaration_scope->is_eval_scope()) {
     Handle<String> type = isolate()->factory()->illegal_return_symbol();
@@ -1944,7 +1936,7 @@ Block* Parser::WithHelper(Expression* obj, ZoneStringList* labels, bool* ok) {
   Statement* stat;
   { Target target(&this->target_stack_, &collector);
     with_nesting_level_++;
-    DeclarationScope()->RecordWithStatement();
+    top_scope_->DeclarationScope()->RecordWithStatement();
     stat = ParseStatement(labels, CHECK_OK);
     with_nesting_level_--;
   }
@@ -3802,7 +3794,7 @@ Expression* Parser::ParseV8Intrinsic(bool* ok) {
   if (extension_ != NULL) {
     // The extension structures are only accessible while parsing the
     // very first time not when reparsing because of lazy compilation.
-    DeclarationScope()->ForceEagerCompilation();
+    top_scope_->DeclarationScope()->ForceEagerCompilation();
   }
 
   const Runtime::Function* function = Runtime::FunctionForSymbol(name);

src/parser.h

@@ -470,8 +470,6 @@ class Parser {
   Mode mode() const { return mode_; }
   ScriptDataImpl* pre_data() const { return pre_data_; }
 
-  Scope* DeclarationScope();
-
   // Check if the given string is 'eval' or 'arguments'.
   bool IsEvalOrArguments(Handle<String> string);
 

src/scopes.cc

@@ -544,6 +544,15 @@ int Scope::ContextChainLength(Scope* scope) {
 }
 
 
+Scope* Scope::DeclarationScope() {
+  Scope* scope = this;
+  while (scope->is_catch_scope()) {
+    scope = scope->outer_scope();
+  }
+  return scope;
+}
+
+
 #ifdef DEBUG
 static const char* Header(Scope::Type type) {
   switch (type) {

src/scopes.h

@@ -290,6 +290,10 @@ class Scope: public ZoneObject {
   // The number of contexts between this and scope; zero if this == scope.
   int ContextChainLength(Scope* scope);
 
+  // Find the first function, global, or eval scope.  This is the scope
+  // where var declarations will be hoisted to in the implementation.
+  Scope* DeclarationScope();
+
   // ---------------------------------------------------------------------------
   // Strict mode support.
   bool IsDeclared(Handle<String> name) {

src/x64/full-codegen-x64.cc

@@ -4180,19 +4180,20 @@ void FullCodeGenerator::LoadContextField(Register dst, int context_index) {
 
 
 void FullCodeGenerator::PushFunctionArgumentForContextAllocation() {
-  if (scope()->is_global_scope()) {
+  Scope* declaration_scope = scope()->DeclarationScope();
+  if (declaration_scope->is_global_scope()) {
     // Contexts nested in the global context have a canonical empty function
     // as their closure, not the anonymous closure containing the global
     // code.  Pass a smi sentinel and let the runtime look up the empty
     // function.
     __ Push(Smi::FromInt(0));
-  } else if (scope()->is_eval_scope()) {
+  } else if (declaration_scope->is_eval_scope()) {
     // Contexts created by a call to eval have the same closure as the
     // context calling eval, not the anonymous closure containing the eval
     // code.  Fetch it from the context.
     __ push(ContextOperand(rsi, Context::CLOSURE_INDEX));
   } else {
-    ASSERT(scope()->is_function_scope() || scope()->is_catch_scope());
+    ASSERT(declaration_scope->is_function_scope());
     __ push(Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   }
 }

test/mjsunit/regress/regress-1528.js

+// Copyright 2011 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// With (or catch) scopes nested inside catch scopes should look at the
+// first outer non-catch scope to decide which closure to use when
+// allocating the new context.
+
+// Code below should not assert or crash.
+try {
+  fail;
+} catch (e) {
+  with({}) {  // With scope inside catch scope.
+    // Dynamic declaration forces runtime lookup to observe the context chain.
+    eval('const x = 7');
+  }
+}