From 7da6d2b0236e32ebbf7309d7db0cb2216d557237 Mon Sep 17 00:00:00 2001 From: "mstarzinger@chromium.org" Date: Tue, 3 Jul 2012 08:41:13 +0000 Subject: [PATCH] Fix lazy compilation for strict eval scopes. This prevents lazy compilation of functions that have an outer context containing a strict eval scope. Such a scope potentially contains context allocated variables in an artificial function scope that is not deserialized correctly. R=ulan@chromium.org BUG=chromium:135066 TEST=mjsunit/regress/regress-crbug-135066 Review URL: https://chromiumcodereview.appspot.com/10704058 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11976 ce2b1a6d-e550-0410-aec6-3dcde31c8c00 --- src/scopes.cc | 40 ++++++++++++--------- src/scopes.h | 6 ++-- test/mjsunit/regress/regress-crbug-135066.js | 53 ++++++++++++++++++++++++++++ 3 files changed, 79 insertions(+), 20 deletions(-) create mode 100644 test/mjsunit/regress/regress-crbug-135066.js diff --git a/src/scopes.cc b/src/scopes.cc index faedb5f..b0fd10e 100644 --- a/src/scopes.cc +++ b/src/scopes.cc @@ -662,28 +662,36 @@ bool Scope::HasTrivialOuterContext() const { } -bool Scope::AllowsLazyCompilation() const { - return !force_eager_compilation_ && - !TrivialDeclarationScopesBeforeWithScope(); +bool Scope::HasLazyCompilableOuterContext() const { + Scope* outer = outer_scope_; + if (outer == NULL) return true; + // There are several reasons that prevent lazy compilation: + // - This scope is inside a with scope and all declaration scopes between + // them have empty contexts. Such declaration scopes become invisible + // during scope info deserialization. + // - This scope is inside a strict eval scope with variables that are + // potentially context allocated in an artificial function scope that + // is not deserialized correctly. + outer = outer->DeclarationScope(); + bool found_non_trivial_declarations = false; + for (const Scope* scope = outer; scope != NULL; scope = scope->outer_scope_) { + if (scope->is_eval_scope()) return false; + if (scope->is_with_scope() && !found_non_trivial_declarations) return false; + if (scope->is_declaration_scope() && scope->num_heap_slots() > 0) { + found_non_trivial_declarations = true; + } + } + return true; } -bool Scope::AllowsLazyCompilationWithoutContext() const { - return !force_eager_compilation_ && HasTrivialOuterContext(); +bool Scope::AllowsLazyCompilation() const { + return !force_eager_compilation_ && HasLazyCompilableOuterContext(); } -bool Scope::TrivialDeclarationScopesBeforeWithScope() const { - Scope* outer = outer_scope_; - if (outer == NULL) return false; - outer = outer->DeclarationScope(); - while (outer != NULL) { - if (outer->is_with_scope()) return true; - if (outer->is_declaration_scope() && outer->num_heap_slots() > 0) - return false; - outer = outer->outer_scope_; - } - return false; +bool Scope::AllowsLazyCompilationWithoutContext() const { + return !force_eager_compilation_ && HasTrivialOuterContext(); } diff --git a/src/scopes.h b/src/scopes.h index 2868cde..42339a9 100644 --- a/src/scopes.h +++ b/src/scopes.h @@ -380,10 +380,8 @@ class Scope: public ZoneObject { // True if the outer context of this scope is always the global context. bool HasTrivialOuterContext() const; - // True if this scope is inside a with scope and all declaration scopes - // between them have empty contexts. Such declaration scopes become - // invisible during scope info deserialization. - bool TrivialDeclarationScopesBeforeWithScope() const; + // True if the outer context allows lazy compilation of this scope. + bool HasLazyCompilableOuterContext() const; // The number of contexts between this and scope; zero if this == scope. int ContextChainLength(Scope* scope); diff --git a/test/mjsunit/regress/regress-crbug-135066.js b/test/mjsunit/regress/regress-crbug-135066.js new file mode 100644 index 0000000..1aeca8b --- /dev/null +++ b/test/mjsunit/regress/regress-crbug-135066.js @@ -0,0 +1,53 @@ +// Copyright 2012 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. + +// Filler long enough to trigger lazy parsing. +var filler = "//" + new Array(1024).join('x'); + +// Test strict eval in global context. +eval( + "'use strict';" + + "var x = 23;" + + "var f = function bozo1() {" + + " return x;" + + "};" + + "assertSame(23, f());" + + filler +); + +// Test default eval in strict context. +(function() { + "use strict"; + eval( + "var y = 42;" + + "var g = function bozo2() {" + + " return y;" + + "};" + + "assertSame(42, g());" + + filler + ); +})(); -- 2.7.4