[webkit-changes] [227692] trunk/Source/JavaScriptCore

Fri, 26 Jan 2018 13:14:38 -0800

Title: [227692] trunk/Source/_javascript_Core
Revision
227692
Author
[email protected]
Date
2018-01-26 13:14:17 -0800 (Fri, 26 Jan 2018)

Log Message

We should only append ParserArenaDeletable pointers to ParserArena::m_deletableObjects.
https://bugs.webkit.org/show_bug.cgi?id=182180
<rdar://problem/36460697>

Reviewed by Michael Saboff.

Some parser Node subclasses extend ParserArenaDeletable via multiple inheritance,
but not as the Node's first base class.  ParserArena::m_deletableObjects is
expecting pointers to objects of the shape of ParserArenaDeletable.  We ensure
this by allocating the Node subclass, and casting it to ParserArenaDeletable to
get the correct pointer to append to ParserArena::m_deletableObjects.

To simplify things, we introduce a JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED 
(analogous to WTF_MAKE_FAST_ALLOCATED) for use in Node subclasses that extends
ParserArenaDeletable.

* parser/NodeConstructors.h:
(JSC::ParserArenaDeletable::operator new):
* parser/Nodes.h:
* parser/ParserArena.h:
(JSC::ParserArena::allocateDeletable):

Modified Paths

Diff

Modified: trunk/Source/_javascript_Core/ChangeLog (227691 => 227692)


--- trunk/Source/_javascript_Core/ChangeLog	2018-01-26 20:55:36 UTC (rev 227691)
+++ trunk/Source/_javascript_Core/ChangeLog	2018-01-26 21:14:17 UTC (rev 227692)
@@ -1,3 +1,27 @@
+2018-01-26  Mark Lam  <[email protected]>
+
+        We should only append ParserArenaDeletable pointers to ParserArena::m_deletableObjects.
+        https://bugs.webkit.org/show_bug.cgi?id=182180
+        <rdar://problem/36460697>
+
+        Reviewed by Michael Saboff.
+
+        Some parser Node subclasses extend ParserArenaDeletable via multiple inheritance,
+        but not as the Node's first base class.  ParserArena::m_deletableObjects is
+        expecting pointers to objects of the shape of ParserArenaDeletable.  We ensure
+        this by allocating the Node subclass, and casting it to ParserArenaDeletable to
+        get the correct pointer to append to ParserArena::m_deletableObjects.
+
+        To simplify things, we introduce a JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED 
+        (analogous to WTF_MAKE_FAST_ALLOCATED) for use in Node subclasses that extends
+        ParserArenaDeletable.
+
+        * parser/NodeConstructors.h:
+        (JSC::ParserArenaDeletable::operator new):
+        * parser/Nodes.h:
+        * parser/ParserArena.h:
+        (JSC::ParserArena::allocateDeletable):
+
 2018-01-26  Joseph Pecoraro  <[email protected]>
 
         _javascript_Core builtins should be partially minified in Release builds not Debug builds

Modified: trunk/Source/_javascript_Core/parser/NodeConstructors.h (227691 => 227692)


--- trunk/Source/_javascript_Core/parser/NodeConstructors.h	2018-01-26 20:55:36 UTC (rev 227691)
+++ trunk/Source/_javascript_Core/parser/NodeConstructors.h	2018-01-26 21:14:17 UTC (rev 227692)
@@ -30,9 +30,10 @@
         return parserArena.allocateFreeable(size);
     }
 
+    template<typename T>
     inline void* ParserArenaDeletable::operator new(size_t size, ParserArena& parserArena)
     {
-        return parserArena.allocateDeletable(size);
+        return parserArena.allocateDeletable<T>(size);
     }
 
     inline ParserArenaRoot::ParserArenaRoot(ParserArena& parserArena)

Modified: trunk/Source/_javascript_Core/parser/Nodes.h (227691 => 227692)


--- trunk/Source/_javascript_Core/parser/Nodes.h	2018-01-26 20:55:36 UTC (rev 227691)
+++ trunk/Source/_javascript_Core/parser/Nodes.h	2018-01-26 21:14:17 UTC (rev 227692)
@@ -113,9 +113,21 @@
 
         // ParserArenaDeletable objects are deleted when the arena is deleted.
         // Clients must not call delete directly on such objects.
-        void* operator new(size_t, ParserArena&);
+        template<typename T> void* operator new(size_t, ParserArena&);
     };
 
+#define JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED_IMPL(__classToNew) \
+        void* operator new(size_t size, ParserArena& parserArena) \
+        { \
+            return ParserArenaDeletable::operator new<__classToNew>(size, parserArena); \
+        }
+
+#define JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(__classToNew) \
+    public: \
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED_IMPL(__classToNew) \
+    private: \
+        typedef int __thisIsHereToForceASemicolonAfterThisMacro
+
     class ParserArenaRoot {
         WTF_MAKE_FAST_ALLOCATED;
     protected:
@@ -238,6 +250,7 @@
     };
 
     class VariableEnvironmentNode : public ParserArenaDeletable {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(VariableEnvironmentNode);
     public:
         typedef DeclarationStacks::FunctionStack FunctionStack;
 
@@ -1413,9 +1426,8 @@
     };
 
     class BlockNode : public StatementNode, public VariableEnvironmentNode {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(BlockNode);
     public:
-        using ParserArenaDeletable::operator new;
-
         BlockNode(const JSTokenLocation&, SourceElements*, VariableEnvironment&, FunctionStack&&);
 
         StatementNode* singleStatement() const;
@@ -1536,9 +1548,8 @@
     };
 
     class ForNode : public StatementNode, public VariableEnvironmentNode {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(ForNode);
     public:
-        using ParserArenaDeletable::operator new;
-
         ForNode(const JSTokenLocation&, ExpressionNode* expr1, ExpressionNode* expr2, ExpressionNode* expr3, StatementNode*, VariableEnvironment&);
 
     private:
@@ -1553,9 +1564,8 @@
     class DestructuringPatternNode;
     
     class EnumerationNode : public StatementNode, public ThrowableExpressionData, public VariableEnvironmentNode {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(EnumerationNode);
     public:
-        using ParserArenaDeletable::operator new;
-
         EnumerationNode(const JSTokenLocation&, ExpressionNode*, ExpressionNode*, StatementNode*, VariableEnvironment&);
 
         ExpressionNode* lexpr() const { return m_lexpr; }
@@ -1568,6 +1578,7 @@
     };
     
     class ForInNode : public EnumerationNode {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(ForInNode);
     public:
         ForInNode(const JSTokenLocation&, ExpressionNode*, ExpressionNode*, StatementNode*, VariableEnvironment&);
 
@@ -1579,6 +1590,7 @@
     };
     
     class ForOfNode : public EnumerationNode {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(ForOfNode);
     public:
         ForOfNode(bool, const JSTokenLocation&, ExpressionNode*, ExpressionNode*, StatementNode*, VariableEnvironment&);
         bool isForOfNode() const override { return true; }
@@ -1668,9 +1680,8 @@
     };
 
     class TryNode : public StatementNode, public VariableEnvironmentNode {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(TryNode);
     public:
-        using ParserArenaDeletable::operator new;
-
         TryNode(const JSTokenLocation&, StatementNode* tryBlock, DestructuringPatternNode* catchPattern, StatementNode* catchBlock, VariableEnvironment& catchEnvironment, StatementNode* finallyBlock);
 
     private:
@@ -1684,12 +1695,15 @@
 
     class ScopeNode : public StatementNode, public ParserArenaRoot, public VariableEnvironmentNode {
     public:
+        // ScopeNode is never directly instantiate. The life-cycle of its derived classes are
+        // managed using std::unique_ptr. Hence, though ScopeNode extends VariableEnvironmentNode,
+        // which in turn extends ParserArenaDeletable, we don't want to use ParserArenaDeletable's
+        // new for allocation.
+        using ParserArenaRoot::operator new;
 
         ScopeNode(ParserArena&, const JSTokenLocation& start, const JSTokenLocation& end, bool inStrictContext);
         ScopeNode(ParserArena&, const JSTokenLocation& start, const JSTokenLocation& end, const SourceCode&, SourceElements*, VariableEnvironment&, FunctionStack&&, VariableEnvironment&, UniquedStringImplPtrSet&&, CodeFeatures, InnerArrowFunctionCodeFeatures, int numConstants);
 
-        using ParserArenaRoot::operator new;
-
         const SourceCode& source() const { return m_source; }
         const String& sourceURL() const { return m_source.provider()->url(); }
         intptr_t sourceID() const { return m_source.providerID(); }
@@ -1831,6 +1845,7 @@
     };
 
     class ImportSpecifierListNode : public ParserArenaDeletable {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(ImportSpecifierListNode);
     public:
         typedef Vector<ImportSpecifierNode*, 3> Specifiers;
 
@@ -1921,6 +1936,7 @@
     };
 
     class ExportSpecifierListNode : public ParserArenaDeletable {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(ExportSpecifierListNode);
     public:
         typedef Vector<ExportSpecifierNode*, 3> Specifiers;
 
@@ -1949,9 +1965,8 @@
     };
 
     class FunctionMetadataNode final : public Node, public ParserArenaDeletable {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(FunctionMetadataNode);
     public:
-        using ParserArenaDeletable::operator new;
-
         FunctionMetadataNode(
             ParserArena&, const JSTokenLocation& start, const JSTokenLocation& end, 
             unsigned startColumn, unsigned endColumn, int functionKeywordStart, 
@@ -2120,9 +2135,8 @@
     };
 
     class ClassExprNode final : public ExpressionNode, public VariableEnvironmentNode {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(ClassExprNode);
     public:
-        using ParserArenaDeletable::operator new;
-
         ClassExprNode(const JSTokenLocation&, const Identifier&, const SourceCode& classSource,
             VariableEnvironment& classEnvironment, ExpressionNode* constructorExpresssion,
             ExpressionNode* parentClass, PropertyListNode* instanceMethods, PropertyListNode* staticMethods);
@@ -2164,9 +2178,8 @@
     };
 
     class ArrayPatternNode : public DestructuringPatternNode, public ThrowableExpressionData, public ParserArenaDeletable {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(ArrayPatternNode);
     public:
-        using ParserArenaDeletable::operator new;
-
         ArrayPatternNode();
         enum class BindingType {
             Elision,
@@ -2194,9 +2207,8 @@
     };
     
     class ObjectPatternNode : public DestructuringPatternNode, public ThrowableExpressionData, public ParserArenaDeletable {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(ObjectPatternNode);
     public:
-        using ParserArenaDeletable::operator new;
-        
         ObjectPatternNode();
         enum class BindingType {
             Element,
@@ -2312,6 +2324,7 @@
     };
 
     class FunctionParameters : public ParserArenaDeletable {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(FunctionParameters);
     public:
         FunctionParameters();
         ALWAYS_INLINE unsigned size() const { return m_patterns.size(); }
@@ -2410,9 +2423,8 @@
     };
 
     class SwitchNode : public StatementNode, public VariableEnvironmentNode {
+        JSC_MAKE_PARSER_ARENA_DELETABLE_ALLOCATED(SwitchNode);
     public:
-        using ParserArenaDeletable::operator new;
-
         SwitchNode(const JSTokenLocation&, ExpressionNode*, CaseBlockNode*, VariableEnvironment&, FunctionStack&&);
 
     private:

Modified: trunk/Source/_javascript_Core/parser/ParserArena.h (227691 => 227692)


--- trunk/Source/_javascript_Core/parser/ParserArena.h	2018-01-26 20:55:36 UTC (rev 227691)
+++ trunk/Source/_javascript_Core/parser/ParserArena.h	2018-01-26 21:14:17 UTC (rev 227692)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2009-2018 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,6 +28,7 @@
 #include "CommonIdentifiers.h"
 #include "Identifier.h"
 #include <array>
+#include <type_traits>
 #include <wtf/SegmentedVector.h>
 
 namespace JSC {
@@ -153,11 +154,17 @@
             return block;
         }
 
+        template<typename T, typename = std::enable_if_t<std::is_base_of<ParserArenaDeletable, T>::value>>
         void* allocateDeletable(size_t size)
         {
-            ParserArenaDeletable* deletable = static_cast<ParserArenaDeletable*>(allocateFreeable(size));
+            // T may extend ParserArenaDeletable via multiple inheritance, but not as T's first
+            // base class. m_deletableObjects is expecting pointers to objects of the shape of
+            // ParserArenaDeletable. We ensure this by allocating T, and casting it to
+            // ParserArenaDeletable to get the correct pointer to append to m_deletableObjects.
+            T* instance = static_cast<T*>(allocateFreeable(size));
+            ParserArenaDeletable* deletable = static_cast<ParserArenaDeletable*>(instance);
             m_deletableObjects.append(deletable);
-            return deletable;
+            return instance;
         }
 
         IdentifierArena& identifierArena()

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