From 635860845790a19bf50bbc51ba8fb66a96dde068 Mon Sep 17 00:00:00 2001
From: The Android Open Source Project <initial-contribution@android.com>
Date: Thu, 5 Mar 2009 14:34:32 -0800
Subject: auto import from //depot/cupcake/@136594

---
 JavaScriptCore/bytecompiler/BytecodeGenerator.h | 480 ++++++++++++++++++++++++
 1 file changed, 480 insertions(+)
 create mode 100644 JavaScriptCore/bytecompiler/BytecodeGenerator.h

(limited to 'JavaScriptCore/bytecompiler/BytecodeGenerator.h')

diff --git a/JavaScriptCore/bytecompiler/BytecodeGenerator.h b/JavaScriptCore/bytecompiler/BytecodeGenerator.h
new file mode 100644
index 0000000..ceb5881
--- /dev/null
+++ b/JavaScriptCore/bytecompiler/BytecodeGenerator.h
@@ -0,0 +1,480 @@
+/*
+ * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  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.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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.
+ */
+
+#ifndef BytecodeGenerator_h
+#define BytecodeGenerator_h
+
+#include "CodeBlock.h"
+#include "HashTraits.h"
+#include "Instruction.h"
+#include "Label.h"
+#include "LabelScope.h"
+#include "Interpreter.h"
+#include "RegisterID.h"
+#include "SegmentedVector.h"
+#include "SymbolTable.h"
+#include "Debugger.h"
+#include "Nodes.h"
+#include <wtf/PassRefPtr.h>
+#include <wtf/Vector.h>
+
+namespace JSC {
+
+    class Identifier;
+    class ScopeChain;
+    class ScopeNode;
+
+    struct FinallyContext {
+        Label* finallyAddr;
+        RegisterID* retAddrDst;
+    };
+
+    struct ControlFlowContext {
+        bool isFinallyBlock;
+        FinallyContext finallyContext;
+    };
+
+    class BytecodeGenerator {
+    public:
+        typedef DeclarationStacks::VarStack VarStack;
+        typedef DeclarationStacks::FunctionStack FunctionStack;
+
+        static void setDumpsGeneratedCode(bool dumpsGeneratedCode);
+        static bool dumpsGeneratedCode();
+
+        BytecodeGenerator(ProgramNode*, const Debugger*, const ScopeChain&, SymbolTable*, ProgramCodeBlock*);
+        BytecodeGenerator(FunctionBodyNode*, const Debugger*, const ScopeChain&, SymbolTable*, CodeBlock*);
+        BytecodeGenerator(EvalNode*, const Debugger*, const ScopeChain&, SymbolTable*, EvalCodeBlock*);
+
+        JSGlobalData* globalData() const { return m_globalData; }
+        const CommonIdentifiers& propertyNames() const { return *m_globalData->propertyNames; }
+
+        void generate();
+
+        // Returns the register corresponding to a local variable, or 0 if no
+        // such register exists. Registers returned by registerFor do not
+        // require explicit reference counting.
+        RegisterID* registerFor(const Identifier&);
+
+        // Behaves as registerFor does, but ignores dynamic scope as
+        // dynamic scope should not interfere with const initialisation
+        RegisterID* constRegisterFor(const Identifier&);
+
+        // Searches the scope chain in an attempt to  statically locate the requested
+        // property.  Returns false if for any reason the property cannot be safely
+        // optimised at all.  Otherwise it will return the index and depth of the
+        // VariableObject that defines the property.  If the property cannot be found
+        // statically, depth will contain the depth of the scope chain where dynamic
+        // lookup must begin.
+        //
+        // NB: depth does _not_ include the local scope.  eg. a depth of 0 refers
+        // to the scope containing this codeblock.
+        bool findScopedProperty(const Identifier&, int& index, size_t& depth, bool forWriting, JSObject*& globalObject);
+
+        // Returns the register storing "this"
+        RegisterID* thisRegister() { return &m_thisRegister; }
+
+        bool isLocal(const Identifier&);
+        bool isLocalConstant(const Identifier&);
+
+        // Returns the next available temporary register. Registers returned by
+        // newTemporary require a modified form of reference counting: any
+        // register with a refcount of 0 is considered "available", meaning that
+        // the next instruction may overwrite it.
+        RegisterID* newTemporary();
+
+        RegisterID* highestUsedRegister();
+
+        // The same as newTemporary(), but this function returns "suggestion" if
+        // "suggestion" is a temporary. This function is helpful in situations
+        // where you've put "suggestion" in a RefPtr, but you'd like to allow
+        // the next instruction to overwrite it anyway.
+        RegisterID* newTemporaryOr(RegisterID* suggestion) { return suggestion->isTemporary() ? suggestion : newTemporary(); }
+
+        // Functions for handling of dst register
+
+        RegisterID* ignoredResult() { return &m_ignoredResultRegister; }
+
+        // Returns a place to write intermediate values of an operation
+        // which reuses dst if it is safe to do so.
+        RegisterID* tempDestination(RegisterID* dst)
+        {
+            return (dst && dst != ignoredResult() && dst->isTemporary()) ? dst : newTemporary();
+        }
+
+        // Returns the place to write the final output of an operation.
+        RegisterID* finalDestination(RegisterID* originalDst, RegisterID* tempDst = 0)
+        {
+            if (originalDst && originalDst != ignoredResult())
+                return originalDst;
+            ASSERT(tempDst != ignoredResult());
+            if (tempDst && tempDst->isTemporary())
+                return tempDst;
+            return newTemporary();
+        }
+
+        RegisterID* destinationForAssignResult(RegisterID* dst)
+        {
+            if (dst && dst != ignoredResult() && m_codeBlock->needsFullScopeChain())
+                return dst->isTemporary() ? dst : newTemporary();
+            return 0;
+        }
+
+        // Moves src to dst if dst is not null and is different from src, otherwise just returns src.
+        RegisterID* moveToDestinationIfNeeded(RegisterID* dst, RegisterID* src)
+        {
+            return dst == ignoredResult() ? 0 : (dst && dst != src) ? emitMove(dst, src) : src;
+        }
+
+        PassRefPtr<LabelScope> newLabelScope(LabelScope::Type, const Identifier* = 0);
+        PassRefPtr<Label> newLabel();
+
+        // The emitNode functions are just syntactic sugar for calling
+        // Node::emitCode. These functions accept a 0 for the register,
+        // meaning that the node should allocate a register, or ignoredResult(),
+        // meaning that the node need not put the result in a register.
+        // Other emit functions do not accept 0 or ignoredResult().
+        RegisterID* emitNode(RegisterID* dst, Node* n)
+        {
+            // Node::emitCode assumes that dst, if provided, is either a local or a referenced temporary.
+            ASSERT(!dst || dst == ignoredResult() || !dst->isTemporary() || dst->refCount());
+            if (!m_codeBlock->numberOfLineInfos() || m_codeBlock->lastLineInfo().lineNumber != n->lineNo()) {
+                LineInfo info = { instructions().size(), n->lineNo() };
+                m_codeBlock->addLineInfo(info);
+            }
+            if (m_emitNodeDepth >= s_maxEmitNodeDepth)
+                return emitThrowExpressionTooDeepException();
+            ++m_emitNodeDepth;
+            RegisterID* r = n->emitBytecode(*this, dst);
+            --m_emitNodeDepth;
+            return r;
+        }
+
+        RegisterID* emitNode(Node* n)
+        {
+            return emitNode(0, n);
+        }
+
+        void emitExpressionInfo(unsigned divot, unsigned startOffset, unsigned endOffset)
+        { 
+            divot -= m_codeBlock->sourceOffset();
+            if (divot > ExpressionRangeInfo::MaxDivot) {
+                // Overflow has occurred, we can only give line number info for errors for this region
+                divot = 0;
+                startOffset = 0;
+                endOffset = 0;
+            } else if (startOffset > ExpressionRangeInfo::MaxOffset) {
+                // If the start offset is out of bounds we clear both offsets
+                // so we only get the divot marker.  Error message will have to be reduced
+                // to line and column number.
+                startOffset = 0;
+                endOffset = 0;
+            } else if (endOffset > ExpressionRangeInfo::MaxOffset) {
+                // The end offset is only used for additional context, and is much more likely
+                // to overflow (eg. function call arguments) so we are willing to drop it without
+                // dropping the rest of the range.
+                endOffset = 0;
+            }
+            
+            ExpressionRangeInfo info;
+            info.instructionOffset = instructions().size();
+            info.divotPoint = divot;
+            info.startOffset = startOffset;
+            info.endOffset = endOffset;
+            m_codeBlock->addExpressionInfo(info);
+        }
+
+        void emitGetByIdExceptionInfo(OpcodeID opcodeID)
+        {
+            // Only op_construct and op_instanceof need exception info for
+            // a preceding op_get_by_id.
+            ASSERT(opcodeID == op_construct || opcodeID == op_instanceof);
+            GetByIdExceptionInfo info;
+            info.bytecodeOffset = instructions().size();
+            info.isOpConstruct = (opcodeID == op_construct);
+            m_codeBlock->addGetByIdExceptionInfo(info);
+        }
+        
+        ALWAYS_INLINE bool leftHandSideNeedsCopy(bool rightHasAssignments, bool rightIsPure)
+        {
+            return (m_codeType != FunctionCode || m_codeBlock->needsFullScopeChain() || rightHasAssignments) && !rightIsPure;
+        }
+
+        ALWAYS_INLINE PassRefPtr<RegisterID> emitNodeForLeftHandSide(ExpressionNode* n, bool rightHasAssignments, bool rightIsPure)
+        {
+            if (leftHandSideNeedsCopy(rightHasAssignments, rightIsPure)) {
+                PassRefPtr<RegisterID> dst = newTemporary();
+                emitNode(dst.get(), n);
+                return dst;
+            }
+
+            return PassRefPtr<RegisterID>(emitNode(n));
+        }
+
+        RegisterID* emitLoad(RegisterID* dst, bool);
+        RegisterID* emitLoad(RegisterID* dst, double);
+        RegisterID* emitLoad(RegisterID* dst, const Identifier&);
+        RegisterID* emitLoad(RegisterID* dst, JSValuePtr);
+        RegisterID* emitUnexpectedLoad(RegisterID* dst, bool);
+        RegisterID* emitUnexpectedLoad(RegisterID* dst, double);
+
+        RegisterID* emitUnaryOp(OpcodeID, RegisterID* dst, RegisterID* src);
+        RegisterID* emitBinaryOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2, OperandTypes);
+        RegisterID* emitEqualityOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2);
+        RegisterID* emitUnaryNoDstOp(OpcodeID, RegisterID* src);
+
+        RegisterID* emitNewObject(RegisterID* dst);
+        RegisterID* emitNewArray(RegisterID* dst, ElementNode*); // stops at first elision
+
+        RegisterID* emitNewFunction(RegisterID* dst, FuncDeclNode* func);
+        RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);
+        RegisterID* emitNewRegExp(RegisterID* dst, RegExp* regExp);
+
+        RegisterID* emitMove(RegisterID* dst, RegisterID* src);
+
+        RegisterID* emitToJSNumber(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_to_jsnumber, dst, src); }
+        RegisterID* emitPreInc(RegisterID* srcDst);
+        RegisterID* emitPreDec(RegisterID* srcDst);
+        RegisterID* emitPostInc(RegisterID* dst, RegisterID* srcDst);
+        RegisterID* emitPostDec(RegisterID* dst, RegisterID* srcDst);
+
+        RegisterID* emitInstanceOf(RegisterID* dst, RegisterID* value, RegisterID* base, RegisterID* basePrototype);
+        RegisterID* emitTypeOf(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_typeof, dst, src); }
+        RegisterID* emitIn(RegisterID* dst, RegisterID* property, RegisterID* base) { return emitBinaryOp(op_in, dst, property, base, OperandTypes()); }
+
+        RegisterID* emitResolve(RegisterID* dst, const Identifier& property);
+        RegisterID* emitGetScopedVar(RegisterID* dst, size_t skip, int index, JSValuePtr globalObject);
+        RegisterID* emitPutScopedVar(size_t skip, int index, RegisterID* value, JSValuePtr globalObject);
+
+        RegisterID* emitResolveBase(RegisterID* dst, const Identifier& property);
+        RegisterID* emitResolveWithBase(RegisterID* baseDst, RegisterID* propDst, const Identifier& property);
+        RegisterID* emitResolveFunction(RegisterID* baseDst, RegisterID* funcDst, const Identifier& property);
+
+        RegisterID* emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property);
+        RegisterID* emitPutById(RegisterID* base, const Identifier& property, RegisterID* value);
+        RegisterID* emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier&);
+        RegisterID* emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
+        RegisterID* emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);
+        RegisterID* emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
+        RegisterID* emitPutByIndex(RegisterID* base, unsigned index, RegisterID* value);
+        RegisterID* emitPutGetter(RegisterID* base, const Identifier& property, RegisterID* value);
+        RegisterID* emitPutSetter(RegisterID* base, const Identifier& property, RegisterID* value);
+
+        RegisterID* emitCall(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+        RegisterID* emitCallEval(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+
+        RegisterID* emitReturn(RegisterID* src);
+        RegisterID* emitEnd(RegisterID* src) { return emitUnaryNoDstOp(op_end, src); }
+
+        RegisterID* emitConstruct(RegisterID* dst, RegisterID* func, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+
+        PassRefPtr<Label> emitLabel(Label*);
+        PassRefPtr<Label> emitJump(Label* target);
+        PassRefPtr<Label> emitJumpIfTrue(RegisterID* cond, Label* target);
+        PassRefPtr<Label> emitJumpIfFalse(RegisterID* cond, Label* target);
+        PassRefPtr<Label> emitJumpScopes(Label* target, int targetScopeDepth);
+
+        PassRefPtr<Label> emitJumpSubroutine(RegisterID* retAddrDst, Label*);
+        void emitSubroutineReturn(RegisterID* retAddrSrc);
+
+        RegisterID* emitGetPropertyNames(RegisterID* dst, RegisterID* base) { return emitUnaryOp(op_get_pnames, dst, base); }
+        RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* iter, Label* target);
+
+        RegisterID* emitCatch(RegisterID*, Label* start, Label* end);
+        void emitThrow(RegisterID* exc) { emitUnaryNoDstOp(op_throw, exc); }
+        RegisterID* emitNewError(RegisterID* dst, ErrorType type, JSValuePtr message);
+        void emitPushNewScope(RegisterID* dst, Identifier& property, RegisterID* value);
+
+        RegisterID* emitPushScope(RegisterID* scope);
+        void emitPopScope();
+
+        void emitDebugHook(DebugHookID, int firstLine, int lastLine);
+
+        int scopeDepth() { return m_dynamicScopeDepth + m_finallyDepth; }
+
+        void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
+        void popFinallyContext();
+
+        LabelScope* breakTarget(const Identifier&);
+        LabelScope* continueTarget(const Identifier&);
+
+        void beginSwitch(RegisterID*, SwitchInfo::SwitchType);
+        void endSwitch(uint32_t clauseCount, RefPtr<Label>*, ExpressionNode**, Label* defaultLabel, int32_t min, int32_t range);
+
+        CodeType codeType() const { return m_codeType; }
+
+        void setRegeneratingForExceptionInfo(CodeBlock* originalCodeBlock)
+        {
+            m_regeneratingForExceptionInfo = true;
+            m_codeBlockBeingRegeneratedFrom = originalCodeBlock;
+        }
+
+    private:
+        void emitOpcode(OpcodeID);
+        void retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index);
+        void retrieveLastUnaryOp(int& dstIndex, int& srcIndex);
+        void rewindBinaryOp();
+        void rewindUnaryOp();
+
+        PassRefPtr<Label> emitComplexJumpScopes(Label* target, ControlFlowContext* topScope, ControlFlowContext* bottomScope);
+
+        struct JSValueHashTraits : HashTraits<JSValueEncodedAsPointer*> {
+            static void constructDeletedValue(JSValueEncodedAsPointer*& slot) { slot = JSValuePtr::encode(jsImpossibleValue()); }
+            static bool isDeletedValue(JSValueEncodedAsPointer* value) { return value == JSValuePtr::encode(jsImpossibleValue()); }
+        };
+
+        typedef HashMap<JSValueEncodedAsPointer*, unsigned, PtrHash<JSValueEncodedAsPointer*>, JSValueHashTraits> JSValueMap;
+
+        struct IdentifierMapIndexHashTraits {
+            typedef int TraitType;
+            typedef IdentifierMapIndexHashTraits StorageTraits;
+            static int emptyValue() { return std::numeric_limits<int>::max(); }
+            static const bool emptyValueIsZero = false;
+            static const bool needsDestruction = false;
+            static const bool needsRef = false;
+        };
+
+        typedef HashMap<RefPtr<UString::Rep>, int, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, IdentifierMapIndexHashTraits> IdentifierMap;
+        typedef HashMap<double, JSValuePtr> NumberMap;
+        typedef HashMap<UString::Rep*, JSString*, IdentifierRepHash> IdentifierStringMap;
+
+        RegisterID* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+        
+        RegisterID* newRegister();
+
+        // Returns the RegisterID corresponding to ident.
+        RegisterID* addVar(const Identifier& ident, bool isConstant)
+        {
+            RegisterID* local;
+            addVar(ident, isConstant, local);
+            return local;
+        }
+        // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
+        bool addVar(const Identifier&, bool isConstant, RegisterID*&);
+
+        // Returns the RegisterID corresponding to ident.
+        RegisterID* addGlobalVar(const Identifier& ident, bool isConstant)
+        {
+            RegisterID* local;
+            addGlobalVar(ident, isConstant, local);
+            return local;
+        }
+        // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
+        bool addGlobalVar(const Identifier&, bool isConstant, RegisterID*&);
+
+        RegisterID* addParameter(const Identifier&);
+        
+        void allocateConstants(size_t);
+
+        RegisterID& registerFor(int index)
+        {
+            if (index >= 0)
+                return m_calleeRegisters[index];
+
+            if (index == RegisterFile::OptionalCalleeArguments)
+                return m_argumentsRegister;
+
+            if (m_parameters.size()) {
+                ASSERT(!m_globals.size());
+                return m_parameters[index + m_parameters.size() + RegisterFile::CallFrameHeaderSize];
+            }
+
+            return m_globals[-index - 1];
+        }
+
+        unsigned addConstant(FuncDeclNode*);
+        unsigned addConstant(FuncExprNode*);
+        unsigned addConstant(const Identifier&);
+        RegisterID* addConstant(JSValuePtr);
+        unsigned addUnexpectedConstant(JSValuePtr);
+        unsigned addRegExp(RegExp*);
+
+        Vector<Instruction>& instructions() { return m_codeBlock->instructions(); }
+        SymbolTable& symbolTable() { return *m_symbolTable; }
+
+        bool shouldOptimizeLocals() { return (m_codeType != EvalCode) && !m_dynamicScopeDepth; }
+        bool canOptimizeNonLocals() { return (m_codeType == FunctionCode) && !m_dynamicScopeDepth && !m_codeBlock->usesEval(); }
+
+        RegisterID* emitThrowExpressionTooDeepException();
+
+        bool m_shouldEmitDebugHooks;
+        bool m_shouldEmitProfileHooks;
+
+        const ScopeChain* m_scopeChain;
+        SymbolTable* m_symbolTable;
+
+        ScopeNode* m_scopeNode;
+        CodeBlock* m_codeBlock;
+
+        HashSet<RefPtr<UString::Rep>, IdentifierRepHash> m_functions;
+        RegisterID m_ignoredResultRegister;
+        RegisterID m_thisRegister;
+        RegisterID m_argumentsRegister;
+        int m_activationRegisterIndex;
+        SegmentedVector<RegisterID, 512> m_calleeRegisters;
+        SegmentedVector<RegisterID, 512> m_parameters;
+        SegmentedVector<RegisterID, 512> m_globals;
+        SegmentedVector<LabelScope, 256> m_labelScopes;
+        SegmentedVector<Label, 256> m_labels;
+        RefPtr<RegisterID> m_lastConstant;
+        int m_finallyDepth;
+        int m_dynamicScopeDepth;
+        int m_baseScopeDepth;
+        CodeType m_codeType;
+
+        Vector<ControlFlowContext> m_scopeContextStack;
+        Vector<SwitchInfo> m_switchContextStack;
+
+        int m_nextGlobalIndex;
+        int m_nextParameterIndex;
+        int m_nextConstantIndex;
+
+        int m_globalVarStorageOffset;
+
+        // Constant pool
+        IdentifierMap m_identifierMap;
+        JSValueMap m_jsValueMap;
+        NumberMap m_numberMap;
+        IdentifierStringMap m_stringMap;
+
+        JSGlobalData* m_globalData;
+
+        OpcodeID m_lastOpcodeID;
+
+        unsigned m_emitNodeDepth;
+
+        bool m_regeneratingForExceptionInfo;
+        CodeBlock* m_codeBlockBeingRegeneratedFrom;
+
+        static const unsigned s_maxEmitNodeDepth = 10000;
+    };
+
+}
+
+#endif // BytecodeGenerator_h
-- 
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