--- old/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/CodeGenerator.java 2020-04-15 18:47:00.000000000 +0530
+++ /dev/null 2020-04-15 18:47:00.000000000 +0530
@@ -1,5588 +0,0 @@
-/*
- * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.nashorn.internal.codegen;
-
-import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.PRIVATE;
-import static jdk.nashorn.internal.codegen.ClassEmitter.Flag.STATIC;
-import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS;
-import static jdk.nashorn.internal.codegen.CompilerConstants.CALLEE;
-import static jdk.nashorn.internal.codegen.CompilerConstants.CREATE_PROGRAM_FUNCTION;
-import static jdk.nashorn.internal.codegen.CompilerConstants.GET_MAP;
-import static jdk.nashorn.internal.codegen.CompilerConstants.GET_STRING;
-import static jdk.nashorn.internal.codegen.CompilerConstants.QUICK_PREFIX;
-import static jdk.nashorn.internal.codegen.CompilerConstants.REGEX_PREFIX;
-import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE;
-import static jdk.nashorn.internal.codegen.CompilerConstants.SPLIT_PREFIX;
-import static jdk.nashorn.internal.codegen.CompilerConstants.THIS;
-import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS;
-import static jdk.nashorn.internal.codegen.CompilerConstants.interfaceCallNoLookup;
-import static jdk.nashorn.internal.codegen.CompilerConstants.methodDescriptor;
-import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
-import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor;
-import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup;
-import static jdk.nashorn.internal.ir.Symbol.HAS_SLOT;
-import static jdk.nashorn.internal.ir.Symbol.IS_INTERNAL;
-import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
-import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid;
-import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_APPLY_TO_CALL;
-import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_DECLARE;
-import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_FAST_SCOPE;
-import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_OPTIMISTIC;
-import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_PROGRAM_POINT_SHIFT;
-import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_SCOPE;
-
-import java.io.PrintWriter;
-import java.util.ArrayDeque;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.BitSet;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Deque;
-import java.util.EnumSet;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.TreeMap;
-import java.util.function.Supplier;
-import jdk.nashorn.internal.AssertsEnabled;
-import jdk.nashorn.internal.IntDeque;
-import jdk.nashorn.internal.codegen.ClassEmitter.Flag;
-import jdk.nashorn.internal.codegen.CompilerConstants.Call;
-import jdk.nashorn.internal.codegen.types.ArrayType;
-import jdk.nashorn.internal.codegen.types.Type;
-import jdk.nashorn.internal.ir.AccessNode;
-import jdk.nashorn.internal.ir.BaseNode;
-import jdk.nashorn.internal.ir.BinaryNode;
-import jdk.nashorn.internal.ir.Block;
-import jdk.nashorn.internal.ir.BlockStatement;
-import jdk.nashorn.internal.ir.BreakNode;
-import jdk.nashorn.internal.ir.CallNode;
-import jdk.nashorn.internal.ir.CaseNode;
-import jdk.nashorn.internal.ir.CatchNode;
-import jdk.nashorn.internal.ir.ContinueNode;
-import jdk.nashorn.internal.ir.EmptyNode;
-import jdk.nashorn.internal.ir.Expression;
-import jdk.nashorn.internal.ir.ExpressionStatement;
-import jdk.nashorn.internal.ir.ForNode;
-import jdk.nashorn.internal.ir.FunctionNode;
-import jdk.nashorn.internal.ir.GetSplitState;
-import jdk.nashorn.internal.ir.IdentNode;
-import jdk.nashorn.internal.ir.IfNode;
-import jdk.nashorn.internal.ir.IndexNode;
-import jdk.nashorn.internal.ir.JoinPredecessorExpression;
-import jdk.nashorn.internal.ir.JumpStatement;
-import jdk.nashorn.internal.ir.JumpToInlinedFinally;
-import jdk.nashorn.internal.ir.LabelNode;
-import jdk.nashorn.internal.ir.LexicalContext;
-import jdk.nashorn.internal.ir.LexicalContextNode;
-import jdk.nashorn.internal.ir.LiteralNode;
-import jdk.nashorn.internal.ir.LiteralNode.ArrayLiteralNode;
-import jdk.nashorn.internal.ir.LiteralNode.PrimitiveLiteralNode;
-import jdk.nashorn.internal.ir.LocalVariableConversion;
-import jdk.nashorn.internal.ir.LoopNode;
-import jdk.nashorn.internal.ir.Node;
-import jdk.nashorn.internal.ir.ObjectNode;
-import jdk.nashorn.internal.ir.Optimistic;
-import jdk.nashorn.internal.ir.PropertyNode;
-import jdk.nashorn.internal.ir.ReturnNode;
-import jdk.nashorn.internal.ir.RuntimeNode;
-import jdk.nashorn.internal.ir.RuntimeNode.Request;
-import jdk.nashorn.internal.ir.SetSplitState;
-import jdk.nashorn.internal.ir.SplitReturn;
-import jdk.nashorn.internal.ir.Splittable;
-import jdk.nashorn.internal.ir.Statement;
-import jdk.nashorn.internal.ir.SwitchNode;
-import jdk.nashorn.internal.ir.Symbol;
-import jdk.nashorn.internal.ir.TernaryNode;
-import jdk.nashorn.internal.ir.ThrowNode;
-import jdk.nashorn.internal.ir.TryNode;
-import jdk.nashorn.internal.ir.UnaryNode;
-import jdk.nashorn.internal.ir.VarNode;
-import jdk.nashorn.internal.ir.WhileNode;
-import jdk.nashorn.internal.ir.WithNode;
-import jdk.nashorn.internal.ir.visitor.NodeOperatorVisitor;
-import jdk.nashorn.internal.ir.visitor.SimpleNodeVisitor;
-import jdk.nashorn.internal.objects.Global;
-import jdk.nashorn.internal.parser.Lexer.RegexToken;
-import jdk.nashorn.internal.parser.TokenType;
-import jdk.nashorn.internal.runtime.Context;
-import jdk.nashorn.internal.runtime.Debug;
-import jdk.nashorn.internal.runtime.ECMAException;
-import jdk.nashorn.internal.runtime.JSType;
-import jdk.nashorn.internal.runtime.OptimisticReturnFilters;
-import jdk.nashorn.internal.runtime.PropertyMap;
-import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData;
-import jdk.nashorn.internal.runtime.RewriteException;
-import jdk.nashorn.internal.runtime.Scope;
-import jdk.nashorn.internal.runtime.ScriptEnvironment;
-import jdk.nashorn.internal.runtime.ScriptFunction;
-import jdk.nashorn.internal.runtime.ScriptObject;
-import jdk.nashorn.internal.runtime.ScriptRuntime;
-import jdk.nashorn.internal.runtime.Source;
-import jdk.nashorn.internal.runtime.Undefined;
-import jdk.nashorn.internal.runtime.UnwarrantedOptimismException;
-import jdk.nashorn.internal.runtime.arrays.ArrayData;
-import jdk.nashorn.internal.runtime.linker.LinkerCallSite;
-import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
-import jdk.nashorn.internal.runtime.logging.DebugLogger;
-import jdk.nashorn.internal.runtime.logging.Loggable;
-import jdk.nashorn.internal.runtime.logging.Logger;
-import jdk.nashorn.internal.runtime.options.Options;
-
-/**
- * This is the lowest tier of the code generator. It takes lowered ASTs emitted
- * from Lower and emits Java byte code. The byte code emission logic is broken
- * out into MethodEmitter. MethodEmitter works internally with a type stack, and
- * keeps track of the contents of the byte code stack. This way we avoid a large
- * number of special cases on the form
- *
- * if (type == INT) {
- * visitInsn(ILOAD, slot);
- * } else if (type == DOUBLE) {
- * visitInsn(DOUBLE, slot);
- * }
- *
- * This quickly became apparent when the code generator was generalized to work
- * with all types, and not just numbers or objects.
- *
- * The CodeGenerator visits nodes only once and emits bytecode for them.
- */
-@Logger(name="codegen")
-final class CodeGenerator extends NodeOperatorVisitor implements Loggable {
-
- private static final Type SCOPE_TYPE = Type.typeFor(ScriptObject.class);
-
- private static final String GLOBAL_OBJECT = Type.getInternalName(Global.class);
-
- private static final Call CREATE_REWRITE_EXCEPTION = CompilerConstants.staticCallNoLookup(RewriteException.class,
- "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class);
- private static final Call CREATE_REWRITE_EXCEPTION_REST_OF = CompilerConstants.staticCallNoLookup(RewriteException.class,
- "create", RewriteException.class, UnwarrantedOptimismException.class, Object[].class, String[].class, int[].class);
-
- private static final Call ENSURE_INT = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
- "ensureInt", int.class, Object.class, int.class);
- private static final Call ENSURE_NUMBER = CompilerConstants.staticCallNoLookup(OptimisticReturnFilters.class,
- "ensureNumber", double.class, Object.class, int.class);
-
- private static final Call CREATE_FUNCTION_OBJECT = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
- "create", ScriptFunction.class, Object[].class, int.class, ScriptObject.class);
- private static final Call CREATE_FUNCTION_OBJECT_NO_SCOPE = CompilerConstants.staticCallNoLookup(ScriptFunction.class,
- "create", ScriptFunction.class, Object[].class, int.class);
-
- private static final Call TO_NUMBER_FOR_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
- "toNumberForEq", double.class, Object.class);
- private static final Call TO_NUMBER_FOR_STRICT_EQ = CompilerConstants.staticCallNoLookup(JSType.class,
- "toNumberForStrictEq", double.class, Object.class);
-
-
- private static final Class ITERATOR_CLASS = Iterator.class;
- static {
- assert ITERATOR_CLASS == CompilerConstants.ITERATOR_PREFIX.type();
- }
- private static final Type ITERATOR_TYPE = Type.typeFor(ITERATOR_CLASS);
- private static final Type EXCEPTION_TYPE = Type.typeFor(CompilerConstants.EXCEPTION_PREFIX.type());
-
- private static final Integer INT_ZERO = 0;
-
- /** Constant data & installation. The only reason the compiler keeps this is because it is assigned
- * by reflection in class installation */
- private final Compiler compiler;
-
- /** Is the current code submitted by 'eval' call? */
- private final boolean evalCode;
-
- /** Call site flags given to the code generator to be used for all generated call sites */
- private final int callSiteFlags;
-
- /** How many regexp fields have been emitted */
- private int regexFieldCount;
-
- /** Line number for last statement. If we encounter a new line number, line number bytecode information
- * needs to be generated */
- private int lastLineNumber = -1;
-
- /** When should we stop caching regexp expressions in fields to limit bytecode size? */
- private static final int MAX_REGEX_FIELDS = 2 * 1024;
-
- /** Current method emitter */
- private MethodEmitter method;
-
- /** Current compile unit */
- private CompileUnit unit;
-
- private final DebugLogger log;
-
- /** From what size should we use spill instead of fields for JavaScript objects? */
- static final int OBJECT_SPILL_THRESHOLD = Options.getIntProperty("nashorn.spill.threshold", 256);
-
- private final Set emittedMethods = new HashSet<>();
-
- // Function Id -> ContinuationInfo. Used by compilation of rest-of function only.
- private ContinuationInfo continuationInfo;
-
- private final Deque scopeEntryLabels = new ArrayDeque<>();
-
- private static final Label METHOD_BOUNDARY = new Label("");
- private final Deque catchLabels = new ArrayDeque<>();
- // Number of live locals on entry to (and thus also break from) labeled blocks.
- private final IntDeque labeledBlockBreakLiveLocals = new IntDeque();
-
- //is this a rest of compilation
- private final int[] continuationEntryPoints;
-
- // Scope object creators needed for for-of and for-in loops
- private final Deque> scopeObjectCreators = new ArrayDeque<>();
-
- /**
- * Constructor.
- *
- * @param compiler
- */
- CodeGenerator(final Compiler compiler, final int[] continuationEntryPoints) {
- super(new CodeGeneratorLexicalContext());
- this.compiler = compiler;
- this.evalCode = compiler.getSource().isEvalCode();
- this.continuationEntryPoints = continuationEntryPoints;
- this.callSiteFlags = compiler.getScriptEnvironment()._callsite_flags;
- this.log = initLogger(compiler.getContext());
- }
-
- @Override
- public DebugLogger getLogger() {
- return log;
- }
-
- @Override
- public DebugLogger initLogger(final Context context) {
- return context.getLogger(this.getClass());
- }
-
- /**
- * Gets the call site flags, adding the strict flag if the current function
- * being generated is in strict mode
- *
- * @return the correct flags for a call site in the current function
- */
- int getCallSiteFlags() {
- return lc.getCurrentFunction().getCallSiteFlags() | callSiteFlags;
- }
-
- /**
- * Gets the flags for a scope call site.
- * @param symbol a scope symbol
- * @return the correct flags for the scope call site
- */
- private int getScopeCallSiteFlags(final Symbol symbol) {
- assert symbol.isScope();
- final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
- if (isEvalCode() && symbol.isGlobal()) {
- return flags; // Don't set fast-scope flag on non-declared globals in eval code - see JDK-8077955.
- }
- return isFastScope(symbol) ? flags | CALLSITE_FAST_SCOPE : flags;
- }
-
- /**
- * Are we generating code for 'eval' code?
- * @return true if currently compiled code is 'eval' code.
- */
- boolean isEvalCode() {
- return evalCode;
- }
-
- /**
- * Are we using dual primitive/object field representation?
- * @return true if using dual field representation, false for object-only fields
- */
- boolean useDualFields() {
- return compiler.getContext().useDualFields();
- }
-
- /**
- * Load an identity node
- *
- * @param identNode an identity node to load
- * @return the method generator used
- */
- private MethodEmitter loadIdent(final IdentNode identNode, final TypeBounds resultBounds) {
- checkTemporalDeadZone(identNode);
- final Symbol symbol = identNode.getSymbol();
-
- if (!symbol.isScope()) {
- final Type type = identNode.getType();
- if(type == Type.UNDEFINED) {
- return method.loadUndefined(resultBounds.widest);
- }
-
- assert symbol.hasSlot() || symbol.isParam();
- return method.load(identNode);
- }
-
- assert identNode.getSymbol().isScope() : identNode + " is not in scope!";
- final int flags = getScopeCallSiteFlags(symbol);
- if (!isFastScope(symbol)) {
- // slow scope load, prototype chain must be inspected at runtime
- new LoadScopeVar(identNode, resultBounds, flags).emit();
- } else if (identNode.isCompileTimePropertyName() || symbol.getUseCount() < SharedScopeCall.SHARED_GET_THRESHOLD) {
- // fast scope load with known prototype depth
- new LoadFastScopeVar(identNode, resultBounds, flags).emit();
- } else {
- // Only generate shared scope getter for often used fast-scope symbols.
- new OptimisticOperation(identNode, resultBounds) {
- @Override
- void loadStack() {
- method.loadCompilerConstant(SCOPE);
- final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol);
- assert depth >= 0;
- method.load(depth);
- method.load(getProgramPoint());
- }
-
- @Override
- void consumeStack() {
- final Type resultType = isOptimistic ? getOptimisticCoercedType() : resultBounds.widest;
- lc.getScopeGet(unit, symbol, resultType, flags, isOptimistic).generateInvoke(method);
- }
- }.emit();
- }
-
- return method;
- }
-
- // Any access to LET and CONST variables before their declaration must throw ReferenceError.
- // This is called the temporal dead zone (TDZ). See https://gist.github.com/rwaldron/f0807a758aa03bcdd58a
- private void checkTemporalDeadZone(final IdentNode identNode) {
- if (identNode.isDead()) {
- method.load(identNode.getSymbol().getName()).invoke(ScriptRuntime.THROW_REFERENCE_ERROR);
- }
- }
-
- // Runtime check for assignment to ES6 const
- private void checkAssignTarget(final Expression expression) {
- if (expression instanceof IdentNode && ((IdentNode)expression).getSymbol().isConst()) {
- method.load(((IdentNode)expression).getSymbol().getName()).invoke(ScriptRuntime.THROW_CONST_TYPE_ERROR);
- }
- }
-
- private boolean isRestOf() {
- return continuationEntryPoints != null;
- }
-
- private boolean isCurrentContinuationEntryPoint(final int programPoint) {
- return isRestOf() && getCurrentContinuationEntryPoint() == programPoint;
- }
-
- private int[] getContinuationEntryPoints() {
- return isRestOf() ? continuationEntryPoints : null;
- }
-
- private int getCurrentContinuationEntryPoint() {
- return isRestOf() ? continuationEntryPoints[0] : INVALID_PROGRAM_POINT;
- }
-
- private boolean isContinuationEntryPoint(final int programPoint) {
- if (isRestOf()) {
- assert continuationEntryPoints != null;
- for (final int cep : continuationEntryPoints) {
- if (cep == programPoint) {
- return true;
- }
- }
- }
- return false;
- }
-
- /**
- * Check if this symbol can be accessed directly with a putfield or getfield or dynamic load
- *
- * @param symbol symbol to check for fast scope
- * @return true if fast scope
- */
- private boolean isFastScope(final Symbol symbol) {
- if (!symbol.isScope()) {
- return false;
- }
-
- if (!lc.inDynamicScope()) {
- // If there's no with or eval in context, and the symbol is marked as scoped, it is fast scoped. Such a
- // symbol must either be global, or its defining block must need scope.
- assert symbol.isGlobal() || lc.getDefiningBlock(symbol).needsScope() : symbol.getName();
- return true;
- }
-
- if (symbol.isGlobal()) {
- // Shortcut: if there's a with or eval in context, globals can't be fast scoped
- return false;
- }
-
- // Otherwise, check if there's a dynamic scope between use of the symbol and its definition
- final String name = symbol.getName();
- boolean previousWasBlock = false;
- for (final Iterator it = lc.getAllNodes(); it.hasNext();) {
- final LexicalContextNode node = it.next();
- if (node instanceof Block) {
- // If this block defines the symbol, then we can fast scope the symbol.
- final Block block = (Block)node;
- if (block.getExistingSymbol(name) == symbol) {
- assert block.needsScope();
- return true;
- }
- previousWasBlock = true;
- } else {
- if (node instanceof WithNode && previousWasBlock || node instanceof FunctionNode && ((FunctionNode)node).needsDynamicScope()) {
- // If we hit a scope that can have symbols introduced into it at run time before finding the defining
- // block, the symbol can't be fast scoped. A WithNode only counts if we've immediately seen a block
- // before - its block. Otherwise, we are currently processing the WithNode's expression, and that's
- // obviously not subjected to introducing new symbols.
- return false;
- }
- previousWasBlock = false;
- }
- }
- // Should've found the symbol defined in a block
- throw new AssertionError();
- }
-
- private class LoadScopeVar extends OptimisticOperation {
- final IdentNode identNode;
- private final int flags;
-
- LoadScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
- super(identNode, resultBounds);
- this.identNode = identNode;
- this.flags = flags;
- }
-
- @Override
- void loadStack() {
- method.loadCompilerConstant(SCOPE);
- getProto();
- }
-
- void getProto() {
- //empty
- }
-
- @Override
- void consumeStack() {
- // If this is either __FILE__, __DIR__, or __LINE__ then load the property initially as Object as we'd convert
- // it anyway for replaceLocationPropertyPlaceholder.
- if(identNode.isCompileTimePropertyName()) {
- method.dynamicGet(Type.OBJECT, identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
- replaceCompileTimeProperty();
- } else {
- dynamicGet(identNode.getSymbol().getName(), flags, identNode.isFunction(), false);
- }
- }
- }
-
- private class LoadFastScopeVar extends LoadScopeVar {
- LoadFastScopeVar(final IdentNode identNode, final TypeBounds resultBounds, final int flags) {
- super(identNode, resultBounds, flags);
- }
-
- @Override
- void getProto() {
- loadFastScopeProto(identNode.getSymbol(), false);
- }
- }
-
- private MethodEmitter storeFastScopeVar(final Symbol symbol, final int flags) {
- loadFastScopeProto(symbol, true);
- method.dynamicSet(symbol.getName(), flags, false);
- return method;
- }
-
- private int getScopeProtoDepth(final Block startingBlock, final Symbol symbol) {
- //walk up the chain from starting block and when we bump into the current function boundary, add the external
- //information.
- final FunctionNode fn = lc.getCurrentFunction();
- final int externalDepth = compiler.getScriptFunctionData(fn.getId()).getExternalSymbolDepth(symbol.getName());
-
- //count the number of scopes from this place to the start of the function
-
- final int internalDepth = FindScopeDepths.findInternalDepth(lc, fn, startingBlock, symbol);
- final int scopesToStart = FindScopeDepths.findScopesToStart(lc, fn, startingBlock);
- int depth = 0;
- if (internalDepth == -1) {
- depth = scopesToStart + externalDepth;
- } else {
- assert internalDepth <= scopesToStart;
- depth = internalDepth;
- }
-
- return depth;
- }
-
- private void loadFastScopeProto(final Symbol symbol, final boolean swap) {
- final int depth = getScopeProtoDepth(lc.getCurrentBlock(), symbol);
- assert depth != -1 : "Couldn't find scope depth for symbol " + symbol.getName() + " in " + lc.getCurrentFunction();
- if (depth > 0) {
- if (swap) {
- method.swap();
- }
- invokeGetProto(depth);
- if (swap) {
- method.swap();
- }
- }
- }
-
- private void invokeGetProto(final int depth) {
- assert depth > 0;
- if (depth > 1) {
- method.load(depth);
- method.invoke(ScriptObject.GET_PROTO_DEPTH);
- } else {
- method.invoke(ScriptObject.GET_PROTO);
- }
- }
-
- /**
- * Generate code that loads this node to the stack, not constraining its type
- *
- * @param expr node to load
- *
- * @return the method emitter used
- */
- private MethodEmitter loadExpressionUnbounded(final Expression expr) {
- return loadExpression(expr, TypeBounds.UNBOUNDED);
- }
-
- private MethodEmitter loadExpressionAsObject(final Expression expr) {
- return loadExpression(expr, TypeBounds.OBJECT);
- }
-
- MethodEmitter loadExpressionAsBoolean(final Expression expr) {
- return loadExpression(expr, TypeBounds.BOOLEAN);
- }
-
- // Test whether conversion from source to target involves a call of ES 9.1 ToPrimitive
- // with possible side effects from calling an object's toString or valueOf methods.
- private static boolean noToPrimitiveConversion(final Type source, final Type target) {
- // Object to boolean conversion does not cause ToPrimitive call
- return source.isJSPrimitive() || !target.isJSPrimitive() || target.isBoolean();
- }
-
- MethodEmitter loadBinaryOperands(final BinaryNode binaryNode) {
- return loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(binaryNode.getWidestOperandType()), false, false);
- }
-
- private MethodEmitter loadBinaryOperands(final Expression lhs, final Expression rhs, final TypeBounds explicitOperandBounds, final boolean baseAlreadyOnStack, final boolean forceConversionSeparation) {
- // ECMAScript 5.1 specification (sections 11.5-11.11 and 11.13) prescribes that when evaluating a binary
- // expression "LEFT op RIGHT", the order of operations must be: LOAD LEFT, LOAD RIGHT, CONVERT LEFT, CONVERT
- // RIGHT, EXECUTE OP. Unfortunately, doing it in this order defeats potential optimizations that arise when we
- // can combine a LOAD with a CONVERT operation (e.g. use a dynamic getter with the conversion target type as its
- // return value). What we do here is reorder LOAD RIGHT and CONVERT LEFT when possible; it is possible only when
- // we can prove that executing CONVERT LEFT can't have a side effect that changes the value of LOAD RIGHT.
- // Basically, if we know that either LEFT already is a primitive value, or does not have to be converted to
- // a primitive value, or RIGHT is an expression that loads without side effects, then we can do the
- // reordering and collapse LOAD/CONVERT into a single operation; otherwise we need to do the more costly
- // separate operations to preserve specification semantics.
-
- // Operands' load type should not be narrower than the narrowest of the individual operand types, nor narrower
- // than the lower explicit bound, but it should also not be wider than
- final Type lhsType = undefinedToNumber(lhs.getType());
- final Type rhsType = undefinedToNumber(rhs.getType());
- final Type narrowestOperandType = Type.narrowest(Type.widest(lhsType, rhsType), explicitOperandBounds.widest);
- final TypeBounds operandBounds = explicitOperandBounds.notNarrowerThan(narrowestOperandType);
- if (noToPrimitiveConversion(lhsType, explicitOperandBounds.widest) || rhs.isLocal()) {
- // Can reorder. We might still need to separate conversion, but at least we can do it with reordering
- if (forceConversionSeparation) {
- // Can reorder, but can't move conversion into the operand as the operation depends on operands
- // exact types for its overflow guarantees. E.g. with {L}{%I}expr1 {L}* {L}{%I}expr2 we are not allowed
- // to merge {L}{%I} into {%L}, as that can cause subsequent overflows; test for JDK-8058610 contains
- // concrete cases where this could happen.
- final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
- loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
- method.convert(operandBounds.within(method.peekType()));
- loadExpression(rhs, safeConvertBounds, false);
- method.convert(operandBounds.within(method.peekType()));
- } else {
- // Can reorder and move conversion into the operand. Combine load and convert into single operations.
- loadExpression(lhs, operandBounds, baseAlreadyOnStack);
- loadExpression(rhs, operandBounds, false);
- }
- } else {
- // Can't reorder. Load and convert separately.
- final TypeBounds safeConvertBounds = TypeBounds.UNBOUNDED.notNarrowerThan(narrowestOperandType);
- loadExpression(lhs, safeConvertBounds, baseAlreadyOnStack);
- final Type lhsLoadedType = method.peekType();
- loadExpression(rhs, safeConvertBounds, false);
- final Type convertedLhsType = operandBounds.within(method.peekType());
- if (convertedLhsType != lhsLoadedType) {
- // Do it conditionally, so that if conversion is a no-op we don't introduce a SWAP, SWAP.
- method.swap().convert(convertedLhsType).swap();
- }
- method.convert(operandBounds.within(method.peekType()));
- }
- assert Type.generic(method.peekType()) == operandBounds.narrowest;
- assert Type.generic(method.peekType(1)) == operandBounds.narrowest;
-
- return method;
- }
-
- /**
- * Similar to {@link #loadBinaryOperands(BinaryNode)} but used specifically for loading operands of
- * relational and equality comparison operators where at least one argument is non-object. (When both
- * arguments are objects, we use {@link ScriptRuntime#EQ(Object, Object)}, {@link ScriptRuntime#LT(Object, Object)}
- * etc. methods instead. Additionally, {@code ScriptRuntime} methods are used for strict (in)equality comparison
- * of a boolean to anything that isn't a boolean.) This method handles the special case where one argument
- * is an object and another is a primitive. Naively, these could also be delegated to {@code ScriptRuntime} methods
- * by boxing the primitive. However, in all such cases the comparison is performed on numeric values, so it is
- * possible to strength-reduce the operation by taking the number value of the object argument instead and
- * comparing that to the primitive value ("primitive" will always be int, long, double, or boolean, and booleans
- * compare as ints in these cases, so they're essentially numbers too). This method will emit code for loading
- * arguments for such strength-reduced comparison. When both arguments are primitives, it just delegates to
- * {@link #loadBinaryOperands(BinaryNode)}.
- *
- * @param cmp the comparison operation for which the operands need to be loaded on stack.
- * @return the current method emitter.
- */
- MethodEmitter loadComparisonOperands(final BinaryNode cmp) {
- final Expression lhs = cmp.lhs();
- final Expression rhs = cmp.rhs();
- final Type lhsType = lhs.getType();
- final Type rhsType = rhs.getType();
-
- // Only used when not both are object, for that we have ScriptRuntime.LT etc.
- assert !(lhsType.isObject() && rhsType.isObject());
-
- if (lhsType.isObject() || rhsType.isObject()) {
- // We can reorder CONVERT LEFT and LOAD RIGHT only if either the left is a primitive, or the right
- // is a local. This is more strict than loadBinaryNode reorder criteria, as it can allow JS primitive
- // types too (notably: String is a JS primitive, but not a JVM primitive). We disallow String otherwise
- // we would prematurely convert it to number when comparing to an optimistic expression, e.g. in
- // "Hello" === String("Hello") the RHS starts out as an optimistic-int function call. If we allowed
- // reordering, we'd end up with ToNumber("Hello") === {I%}String("Hello") that is obviously incorrect.
- final boolean canReorder = lhsType.isPrimitive() || rhs.isLocal();
- // If reordering is allowed, and we're using a relational operator (that is, <, <=, >, >=) and not an
- // (in)equality operator, then we encourage combining of LOAD and CONVERT into a single operation.
- // This is because relational operators' semantics prescribes vanilla ToNumber() conversion, while
- // (in)equality operators need the specialized JSType.toNumberFor[Strict]Equals. E.g. in the code snippet
- // "i < obj.size" (where i is primitive and obj.size is statically an object), ".size" will thus be allowed
- // to compile as:
- // invokedynamic GET_PROPERTY:size(Object;)D
- // instead of the more costly:
- // invokedynamic GET_PROPERTY:size(Object;)Object
- // invokestatic JSType.toNumber(Object)D
- // Note also that even if this is allowed, we're only using it on operands that are non-optimistic, as
- // otherwise the logic for determining effective optimistic-ness would turn an optimistic double return
- // into a freely coercible one, which would be wrong.
- final boolean canCombineLoadAndConvert = canReorder && cmp.isRelational();
-
- // LOAD LEFT
- loadExpression(lhs, canCombineLoadAndConvert && !lhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
-
- final Type lhsLoadedType = method.peekType();
- final TokenType tt = cmp.tokenType();
- if (canReorder) {
- // Can reorder CONVERT LEFT and LOAD RIGHT
- emitObjectToNumberComparisonConversion(method, tt);
- loadExpression(rhs, canCombineLoadAndConvert && !rhs.isOptimistic() ? TypeBounds.NUMBER : TypeBounds.UNBOUNDED);
- } else {
- // Can't reorder CONVERT LEFT and LOAD RIGHT
- loadExpression(rhs, TypeBounds.UNBOUNDED);
- if (lhsLoadedType != Type.NUMBER) {
- method.swap();
- emitObjectToNumberComparisonConversion(method, tt);
- method.swap();
- }
- }
-
- // CONVERT RIGHT
- emitObjectToNumberComparisonConversion(method, tt);
- return method;
- }
- // For primitive operands, just don't do anything special.
- return loadBinaryOperands(cmp);
- }
-
- private static void emitObjectToNumberComparisonConversion(final MethodEmitter method, final TokenType tt) {
- switch(tt) {
- case EQ:
- case NE:
- if (method.peekType().isObject()) {
- TO_NUMBER_FOR_EQ.invoke(method);
- return;
- }
- break;
- case EQ_STRICT:
- case NE_STRICT:
- if (method.peekType().isObject()) {
- TO_NUMBER_FOR_STRICT_EQ.invoke(method);
- return;
- }
- break;
- default:
- break;
- }
- method.convert(Type.NUMBER);
- }
-
- private static Type undefinedToNumber(final Type type) {
- return type == Type.UNDEFINED ? Type.NUMBER : type;
- }
-
- private static final class TypeBounds {
- final Type narrowest;
- final Type widest;
-
- static final TypeBounds UNBOUNDED = new TypeBounds(Type.UNKNOWN, Type.OBJECT);
- static final TypeBounds INT = exact(Type.INT);
- static final TypeBounds NUMBER = exact(Type.NUMBER);
- static final TypeBounds OBJECT = exact(Type.OBJECT);
- static final TypeBounds BOOLEAN = exact(Type.BOOLEAN);
-
- static TypeBounds exact(final Type type) {
- return new TypeBounds(type, type);
- }
-
- TypeBounds(final Type narrowest, final Type widest) {
- assert widest != null && widest != Type.UNDEFINED && widest != Type.UNKNOWN : widest;
- assert narrowest != null && narrowest != Type.UNDEFINED : narrowest;
- assert !narrowest.widerThan(widest) : narrowest + " wider than " + widest;
- assert !widest.narrowerThan(narrowest);
- this.narrowest = Type.generic(narrowest);
- this.widest = Type.generic(widest);
- }
-
- TypeBounds notNarrowerThan(final Type type) {
- return maybeNew(Type.narrowest(Type.widest(narrowest, type), widest), widest);
- }
-
- TypeBounds notWiderThan(final Type type) {
- return maybeNew(Type.narrowest(narrowest, type), Type.narrowest(widest, type));
- }
-
- boolean canBeNarrowerThan(final Type type) {
- return narrowest.narrowerThan(type);
- }
-
- TypeBounds maybeNew(final Type newNarrowest, final Type newWidest) {
- if(newNarrowest == narrowest && newWidest == widest) {
- return this;
- }
- return new TypeBounds(newNarrowest, newWidest);
- }
-
- TypeBounds booleanToInt() {
- return maybeNew(CodeGenerator.booleanToInt(narrowest), CodeGenerator.booleanToInt(widest));
- }
-
- TypeBounds objectToNumber() {
- return maybeNew(CodeGenerator.objectToNumber(narrowest), CodeGenerator.objectToNumber(widest));
- }
-
- Type within(final Type type) {
- if(type.narrowerThan(narrowest)) {
- return narrowest;
- }
- if(type.widerThan(widest)) {
- return widest;
- }
- return type;
- }
-
- @Override
- public String toString() {
- return "[" + narrowest + ", " + widest + "]";
- }
- }
-
- private static Type booleanToInt(final Type t) {
- return t == Type.BOOLEAN ? Type.INT : t;
- }
-
- private static Type objectToNumber(final Type t) {
- return t.isObject() ? Type.NUMBER : t;
- }
-
- MethodEmitter loadExpressionAsType(final Expression expr, final Type type) {
- if(type == Type.BOOLEAN) {
- return loadExpressionAsBoolean(expr);
- } else if(type == Type.UNDEFINED) {
- assert expr.getType() == Type.UNDEFINED;
- return loadExpressionAsObject(expr);
- }
- // having no upper bound preserves semantics of optimistic operations in the expression (by not having them
- // converted early) and then applies explicit conversion afterwards.
- return loadExpression(expr, TypeBounds.UNBOUNDED.notNarrowerThan(type)).convert(type);
- }
-
- private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds) {
- return loadExpression(expr, resultBounds, false);
- }
-
- /**
- * Emits code for evaluating an expression and leaving its value on top of the stack, narrowing or widening it if
- * necessary.
- * @param expr the expression to load
- * @param resultBounds the incoming type bounds. The value on the top of the stack is guaranteed to not be of narrower
- * type than the narrowest bound, or wider type than the widest bound after it is loaded.
- * @param baseAlreadyOnStack true if the base of an access or index node is already on the stack. Used to avoid
- * double evaluation of bases in self-assignment expressions to access and index nodes. {@code Type.OBJECT} is used
- * to indicate the widest possible type.
- * @return the method emitter
- */
- private MethodEmitter loadExpression(final Expression expr, final TypeBounds resultBounds, final boolean baseAlreadyOnStack) {
-
- /*
- * The load may be of type IdentNode, e.g. "x", AccessNode, e.g. "x.y"
- * or IndexNode e.g. "x[y]". Both AccessNodes and IndexNodes are
- * BaseNodes and the logic for loading the base object is reused
- */
- final CodeGenerator codegen = this;
-
- final boolean isCurrentDiscard = codegen.lc.isCurrentDiscard(expr);
- expr.accept(new NodeOperatorVisitor(new LexicalContext()) {
- @Override
- public boolean enterIdentNode(final IdentNode identNode) {
- loadIdent(identNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterAccessNode(final AccessNode accessNode) {
- new OptimisticOperation(accessNode, resultBounds) {
- @Override
- void loadStack() {
- if (!baseAlreadyOnStack) {
- loadExpressionAsObject(accessNode.getBase());
- }
- assert method.peekType().isObject();
- }
- @Override
- void consumeStack() {
- final int flags = getCallSiteFlags();
- dynamicGet(accessNode.getProperty(), flags, accessNode.isFunction(), accessNode.isIndex());
- }
- }.emit(baseAlreadyOnStack ? 1 : 0);
- return false;
- }
-
- @Override
- public boolean enterIndexNode(final IndexNode indexNode) {
- new OptimisticOperation(indexNode, resultBounds) {
- @Override
- void loadStack() {
- if (!baseAlreadyOnStack) {
- loadExpressionAsObject(indexNode.getBase());
- loadExpressionUnbounded(indexNode.getIndex());
- }
- }
- @Override
- void consumeStack() {
- final int flags = getCallSiteFlags();
- dynamicGetIndex(flags, indexNode.isFunction());
- }
- }.emit(baseAlreadyOnStack ? 2 : 0);
- return false;
- }
-
- @Override
- public boolean enterFunctionNode(final FunctionNode functionNode) {
- // function nodes will always leave a constructed function object on stack, no need to load the symbol
- // separately as in enterDefault()
- lc.pop(functionNode);
- functionNode.accept(codegen);
- // NOTE: functionNode.accept() will produce a different FunctionNode that we discard. This incidentally
- // doesn't cause problems as we're never touching FunctionNode again after it's visited here - codegen
- // is the last element in the compilation pipeline, the AST it produces is not used externally. So, we
- // re-push the original functionNode.
- lc.push(functionNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_ADD(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_ADD(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_BIT_AND(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_BIT_AND(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_BIT_OR(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_BIT_OR(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_BIT_XOR(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_BIT_XOR(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_DIV(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_DIV(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_MOD(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_MOD(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_MUL(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_MUL(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_SAR(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_SAR(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_SHL(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_SHL(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_SHR(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_SHR(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterASSIGN_SUB(final BinaryNode binaryNode) {
- checkAssignTarget(binaryNode.lhs());
- loadASSIGN_SUB(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterCallNode(final CallNode callNode) {
- return loadCallNode(callNode, resultBounds);
- }
-
- @Override
- public boolean enterLiteralNode(final LiteralNode literalNode) {
- loadLiteral(literalNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterTernaryNode(final TernaryNode ternaryNode) {
- loadTernaryNode(ternaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterADD(final BinaryNode binaryNode) {
- loadADD(binaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterNEG(final UnaryNode unaryNode) {
- loadSUB(unaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterSUB(final BinaryNode binaryNode) {
- loadSUB(binaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterMUL(final BinaryNode binaryNode) {
- loadMUL(binaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterDIV(final BinaryNode binaryNode) {
- loadDIV(binaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterMOD(final BinaryNode binaryNode) {
- loadMOD(binaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterSAR(final BinaryNode binaryNode) {
- loadSAR(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterSHL(final BinaryNode binaryNode) {
- loadSHL(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterSHR(final BinaryNode binaryNode) {
- loadSHR(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterCOMMARIGHT(final BinaryNode binaryNode) {
- loadCOMMARIGHT(binaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterAND(final BinaryNode binaryNode) {
- loadAND_OR(binaryNode, resultBounds, true);
- return false;
- }
-
- @Override
- public boolean enterOR(final BinaryNode binaryNode) {
- loadAND_OR(binaryNode, resultBounds, false);
- return false;
- }
-
- @Override
- public boolean enterNOT(final UnaryNode unaryNode) {
- loadNOT(unaryNode);
- return false;
- }
-
- @Override
- public boolean enterPOS(final UnaryNode unaryNode) {
- loadADD(unaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterBIT_NOT(final UnaryNode unaryNode) {
- loadBIT_NOT(unaryNode);
- return false;
- }
-
- @Override
- public boolean enterBIT_AND(final BinaryNode binaryNode) {
- loadBIT_AND(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterBIT_OR(final BinaryNode binaryNode) {
- loadBIT_OR(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterBIT_XOR(final BinaryNode binaryNode) {
- loadBIT_XOR(binaryNode);
- return false;
- }
-
- @Override
- public boolean enterVOID(final UnaryNode unaryNode) {
- loadVOID(unaryNode, resultBounds);
- return false;
- }
-
- @Override
- public boolean enterDELETE(final UnaryNode unaryNode) {
- loadDELETE(unaryNode);
- return false;
- }
-
- @Override
- public boolean enterEQ(final BinaryNode binaryNode) {
- loadCmp(binaryNode, Condition.EQ);
- return false;
- }
-
- @Override
- public boolean enterEQ_STRICT(final BinaryNode binaryNode) {
- loadCmp(binaryNode, Condition.EQ);
- return false;
- }
-
- @Override
- public boolean enterGE(final BinaryNode binaryNode) {
- loadCmp(binaryNode, Condition.GE);
- return false;
- }
-
- @Override
- public boolean enterGT(final BinaryNode binaryNode) {
- loadCmp(binaryNode, Condition.GT);
- return false;
- }
-
- @Override
- public boolean enterLE(final BinaryNode binaryNode) {
- loadCmp(binaryNode, Condition.LE);
- return false;
- }
-
- @Override
- public boolean enterLT(final BinaryNode binaryNode) {
- loadCmp(binaryNode, Condition.LT);
- return false;
- }
-
- @Override
- public boolean enterNE(final BinaryNode binaryNode) {
- loadCmp(binaryNode, Condition.NE);
- return false;
- }
-
- @Override
- public boolean enterNE_STRICT(final BinaryNode binaryNode) {
- loadCmp(binaryNode, Condition.NE);
- return false;
- }
-
- @Override
- public boolean enterObjectNode(final ObjectNode objectNode) {
- loadObjectNode(objectNode);
- return false;
- }
-
- @Override
- public boolean enterRuntimeNode(final RuntimeNode runtimeNode) {
- loadRuntimeNode(runtimeNode);
- return false;
- }
-
- @Override
- public boolean enterNEW(final UnaryNode unaryNode) {
- loadNEW(unaryNode);
- return false;
- }
-
- @Override
- public boolean enterDECINC(final UnaryNode unaryNode) {
- checkAssignTarget(unaryNode.getExpression());
- loadDECINC(unaryNode);
- return false;
- }
-
- @Override
- public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression joinExpr) {
- loadMaybeDiscard(joinExpr, joinExpr.getExpression(), resultBounds);
- return false;
- }
-
- @Override
- public boolean enterGetSplitState(final GetSplitState getSplitState) {
- method.loadScope();
- method.invoke(Scope.GET_SPLIT_STATE);
- return false;
- }
-
- @Override
- public boolean enterDefault(final Node otherNode) {
- // Must have handled all expressions that can legally be encountered.
- throw new AssertionError(otherNode.getClass().getName());
- }
- });
- if(!isCurrentDiscard) {
- coerceStackTop(resultBounds);
- }
- return method;
- }
-
- private MethodEmitter coerceStackTop(final TypeBounds typeBounds) {
- return method.convert(typeBounds.within(method.peekType()));
- }
-
- /**
- * Closes any still open entries for this block's local variables in the bytecode local variable table.
- *
- * @param block block containing symbols.
- */
- private void closeBlockVariables(final Block block) {
- for (final Symbol symbol : block.getSymbols()) {
- if (symbol.isBytecodeLocal()) {
- method.closeLocalVariable(symbol, block.getBreakLabel());
- }
- }
- }
-
- @Override
- public boolean enterBlock(final Block block) {
- final Label entryLabel = block.getEntryLabel();
- if (entryLabel.isBreakTarget()) {
- // Entry label is a break target only for an inlined finally block.
- assert !method.isReachable();
- method.breakLabel(entryLabel, lc.getUsedSlotCount());
- } else {
- method.label(entryLabel);
- }
- if(!method.isReachable()) {
- return false;
- }
- if(lc.isFunctionBody() && emittedMethods.contains(lc.getCurrentFunction().getName())) {
- return false;
- }
- initLocals(block);
-
- assert lc.getUsedSlotCount() == method.getFirstTemp();
- return true;
- }
-
- boolean useOptimisticTypes() {
- return !lc.inSplitLiteral() && compiler.useOptimisticTypes();
- }
-
- @Override
- public Node leaveBlock(final Block block) {
- popBlockScope(block);
- method.beforeJoinPoint(block);
-
- closeBlockVariables(block);
- lc.releaseSlots();
- assert !method.isReachable() || (lc.isFunctionBody() ? 0 : lc.getUsedSlotCount()) == method.getFirstTemp() :
- "reachable="+method.isReachable() +
- " isFunctionBody=" + lc.isFunctionBody() +
- " usedSlotCount=" + lc.getUsedSlotCount() +
- " firstTemp=" + method.getFirstTemp();
-
- return block;
- }
-
- private void popBlockScope(final Block block) {
- final Label breakLabel = block.getBreakLabel();
-
- if (block.providesScopeCreator()) {
- scopeObjectCreators.pop();
- }
- if(!block.needsScope() || lc.isFunctionBody()) {
- emitBlockBreakLabel(breakLabel);
- return;
- }
-
- final Label beginTryLabel = scopeEntryLabels.pop();
- final Label recoveryLabel = new Label("block_popscope_catch");
- emitBlockBreakLabel(breakLabel);
- final boolean bodyCanThrow = breakLabel.isAfter(beginTryLabel);
- if(bodyCanThrow) {
- method._try(beginTryLabel, breakLabel, recoveryLabel);
- }
-
- Label afterCatchLabel = null;
-
- if(method.isReachable()) {
- popScope();
- if(bodyCanThrow) {
- afterCatchLabel = new Label("block_after_catch");
- method._goto(afterCatchLabel);
- }
- }
-
- if(bodyCanThrow) {
- assert !method.isReachable();
- method._catch(recoveryLabel);
- popScopeException();
- method.athrow();
- }
- if(afterCatchLabel != null) {
- method.label(afterCatchLabel);
- }
- }
-
- private void emitBlockBreakLabel(final Label breakLabel) {
- // TODO: this is totally backwards. Block should not be breakable, LabelNode should be breakable.
- final LabelNode labelNode = lc.getCurrentBlockLabelNode();
- if(labelNode != null) {
- // Only have conversions if we're reachable
- assert labelNode.getLocalVariableConversion() == null || method.isReachable();
- method.beforeJoinPoint(labelNode);
- method.breakLabel(breakLabel, labeledBlockBreakLiveLocals.pop());
- } else {
- method.label(breakLabel);
- }
- }
-
- private void popScope() {
- popScopes(1);
- }
-
- /**
- * Pop scope as part of an exception handler. Similar to {@code popScope()} but also takes care of adjusting the
- * number of scopes that needs to be popped in case a rest-of continuation handler encounters an exception while
- * performing a ToPrimitive conversion.
- */
- private void popScopeException() {
- popScope();
- final ContinuationInfo ci = getContinuationInfo();
- if(ci != null) {
- final Label catchLabel = ci.catchLabel;
- if(catchLabel != METHOD_BOUNDARY && catchLabel == catchLabels.peek()) {
- ++ci.exceptionScopePops;
- }
- }
- }
-
- private void popScopesUntil(final LexicalContextNode until) {
- popScopes(lc.getScopeNestingLevelTo(until));
- }
-
- private void popScopes(final int count) {
- if(count == 0) {
- return;
- }
- assert count > 0; // together with count == 0 check, asserts nonnegative count
- if (!method.hasScope()) {
- // We can sometimes invoke this method even if the method has no slot for the scope object. Typical example:
- // for(;;) { with({}) { break; } }. WithNode normally creates a scope, but if it uses no identifiers and
- // nothing else forces creation of a scope in the method, we just won't have the :scope local variable.
- return;
- }
- method.loadCompilerConstant(SCOPE);
- invokeGetProto(count);
- method.storeCompilerConstant(SCOPE);
- }
-
- @Override
- public boolean enterBreakNode(final BreakNode breakNode) {
- return enterJumpStatement(breakNode);
- }
-
- @Override
- public boolean enterJumpToInlinedFinally(final JumpToInlinedFinally jumpToInlinedFinally) {
- return enterJumpStatement(jumpToInlinedFinally);
- }
-
- private boolean enterJumpStatement(final JumpStatement jump) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(jump);
-
- method.beforeJoinPoint(jump);
- popScopesUntil(jump.getPopScopeLimit(lc));
- final Label targetLabel = jump.getTargetLabel(lc);
- targetLabel.markAsBreakTarget();
- method._goto(targetLabel);
-
- return false;
- }
-
- private int loadArgs(final List args) {
- final int argCount = args.size();
- // arg have already been converted to objects here.
- if (argCount > LinkerCallSite.ARGLIMIT) {
- loadArgsArray(args);
- return 1;
- }
-
- for (final Expression arg : args) {
- assert arg != null;
- loadExpressionUnbounded(arg);
- }
- return argCount;
- }
-
- private boolean loadCallNode(final CallNode callNode, final TypeBounds resultBounds) {
- lineNumber(callNode.getLineNumber());
-
- final List args = callNode.getArgs();
- final Expression function = callNode.getFunction();
- final Block currentBlock = lc.getCurrentBlock();
- final CodeGeneratorLexicalContext codegenLexicalContext = lc;
-
- function.accept(new SimpleNodeVisitor() {
-
- private MethodEmitter sharedScopeCall(final IdentNode identNode, final int flags) {
- final Symbol symbol = identNode.getSymbol();
- assert isFastScope(symbol);
-
- new OptimisticOperation(callNode, resultBounds) {
- @Override
- void loadStack() {
- method.loadCompilerConstant(SCOPE);
- final int depth = getScopeProtoDepth(currentBlock, symbol);
- assert depth >= 0;
- method.load(depth);
- method.load(getProgramPoint());
- loadArgs(args);
- }
-
- @Override
- void consumeStack() {
- final Type[] paramTypes = method.getTypesFromStack(args.size());
- // We have trouble finding e.g. in Type.typeFor(asm.Type) because it can't see the Context class
- // loader, so we need to weaken reference signatures to Object.
- for(int i = 0; i < paramTypes.length; ++i) {
- paramTypes[i] = Type.generic(paramTypes[i]);
- }
-
- final Type resultType = isOptimistic ? getOptimisticCoercedType() : resultBounds.widest;
- final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol,
- identNode.getType(), resultType, paramTypes, flags, isOptimistic);
- scopeCall.generateInvoke(method);
- }
- }.emit();
-
- return method;
- }
-
- private void scopeCall(final IdentNode ident, final int flags) {
- new OptimisticOperation(callNode, resultBounds) {
- int argsCount;
- @Override
- void loadStack() {
- loadExpressionAsObject(ident); // foo() makes no sense if foo == 3
- // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly.
- method.loadUndefined(Type.OBJECT); //the 'this'
- argsCount = loadArgs(args);
- }
- @Override
- void consumeStack() {
- dynamicCall(2 + argsCount, flags, ident.getName());
- }
- }.emit();
- }
-
- private void evalCall(final IdentNode ident, final int flags) {
- final Label invoke_direct_eval = new Label("invoke_direct_eval");
- final Label is_not_eval = new Label("is_not_eval");
- final Label eval_done = new Label("eval_done");
-
- new OptimisticOperation(callNode, resultBounds) {
- int argsCount;
- @Override
- void loadStack() {
- /*
- * We want to load 'eval' to check if it is indeed global builtin eval.
- * If this eval call is inside a 'with' statement, GET_METHOD_PROPERTY
- * would be generated if ident is a "isFunction". But, that would result in a
- * bound function from WithObject. We don't want that as bound function as that
- * won't be detected as builtin eval. So, we make ident as "not a function" which
- * results in GET_PROPERTY being generated and so WithObject
- * would return unbounded eval function.
- *
- * Example:
- *
- * var global = this;
- * function func() {
- * with({ eval: global.eval) { eval("var x = 10;") }
- * }
- */
- loadExpressionAsObject(ident.setIsNotFunction()); // Type.OBJECT as foo() makes no sense if foo == 3
- globalIsEval();
- method.ifeq(is_not_eval);
-
- // Load up self (scope).
- method.loadCompilerConstant(SCOPE);
- final List evalArgs = callNode.getEvalArgs().getArgs();
- // load evaluated code
- loadExpressionAsObject(evalArgs.get(0));
- // load second and subsequent args for side-effect
- final int numArgs = evalArgs.size();
- for (int i = 1; i < numArgs; i++) {
- loadAndDiscard(evalArgs.get(i));
- }
- method._goto(invoke_direct_eval);
-
- method.label(is_not_eval);
- // load this time but with GET_METHOD_PROPERTY
- loadExpressionAsObject(ident); // Type.OBJECT as foo() makes no sense if foo == 3
- // This is some scope 'eval' or global eval replaced by user
- // but not the built-in ECMAScript 'eval' function call
- method.loadNull();
- argsCount = loadArgs(callNode.getArgs());
- }
-
- @Override
- void consumeStack() {
- // Ordinary call
- dynamicCall(2 + argsCount, flags, "eval");
- method._goto(eval_done);
-
- method.label(invoke_direct_eval);
- // Special/extra 'eval' arguments. These can be loaded late (in consumeStack) as we know none of
- // them can ever be optimistic.
- method.loadCompilerConstant(THIS);
- method.load(callNode.getEvalArgs().getLocation());
- method.load(CodeGenerator.this.lc.getCurrentFunction().isStrict());
- // direct call to Global.directEval
- globalDirectEval();
- convertOptimisticReturnValue();
- coerceStackTop(resultBounds);
- }
- }.emit();
-
- method.label(eval_done);
- }
-
- @Override
- public boolean enterIdentNode(final IdentNode node) {
- final Symbol symbol = node.getSymbol();
-
- if (symbol.isScope()) {
- final int flags = getScopeCallSiteFlags(symbol);
- final int useCount = symbol.getUseCount();
-
- // We only use shared scope calls for fast scopes
- if (callNode.isEval()) {
- evalCall(node, flags);
- } else if (!isFastScope(symbol) || symbol.getUseCount() < SharedScopeCall.SHARED_CALL_THRESHOLD) {
- scopeCall(node, flags);
- } else {
- sharedScopeCall(node, flags);
- }
- assert method.peekType().equals(resultBounds.within(callNode.getType())) : method.peekType() + " != " + resultBounds + "(" + callNode.getType() + ")";
- } else {
- enterDefault(node);
- }
-
- return false;
- }
-
- @Override
- public boolean enterAccessNode(final AccessNode node) {
- //check if this is an apply to call node. only real applies, that haven't been
- //shadowed from their way to the global scope counts
-
- //call nodes have program points.
-
- final int flags = getCallSiteFlags() | (callNode.isApplyToCall() ? CALLSITE_APPLY_TO_CALL : 0);
-
- new OptimisticOperation(callNode, resultBounds) {
- int argCount;
- @Override
- void loadStack() {
- loadExpressionAsObject(node.getBase());
- method.dup();
- // NOTE: not using a nested OptimisticOperation on this dynamicGet, as we expect to get back
- // a callable object. Nobody in their right mind would optimistically type this call site.
- assert !node.isOptimistic();
- method.dynamicGet(node.getType(), node.getProperty(), flags, true, node.isIndex());
- method.swap();
- argCount = loadArgs(args);
- }
- @Override
- void consumeStack() {
- dynamicCall(2 + argCount, flags, node.toString(false));
- }
- }.emit();
-
- return false;
- }
-
- @Override
- public boolean enterFunctionNode(final FunctionNode origCallee) {
- new OptimisticOperation(callNode, resultBounds) {
- FunctionNode callee;
- int argsCount;
- @Override
- void loadStack() {
- callee = (FunctionNode)origCallee.accept(CodeGenerator.this);
- if (callee.isStrict()) { // "this" is undefined
- method.loadUndefined(Type.OBJECT);
- } else { // get global from scope (which is the self)
- globalInstance();
- }
- argsCount = loadArgs(args);
- }
-
- @Override
- void consumeStack() {
- dynamicCall(2 + argsCount, getCallSiteFlags(), null);
- }
- }.emit();
- return false;
- }
-
- @Override
- public boolean enterIndexNode(final IndexNode node) {
- new OptimisticOperation(callNode, resultBounds) {
- int argsCount;
- @Override
- void loadStack() {
- loadExpressionAsObject(node.getBase());
- method.dup();
- final Type indexType = node.getIndex().getType();
- if (indexType.isObject() || indexType.isBoolean()) {
- loadExpressionAsObject(node.getIndex()); //TODO boolean
- } else {
- loadExpressionUnbounded(node.getIndex());
- }
- // NOTE: not using a nested OptimisticOperation on this dynamicGetIndex, as we expect to get
- // back a callable object. Nobody in their right mind would optimistically type this call site.
- assert !node.isOptimistic();
- method.dynamicGetIndex(node.getType(), getCallSiteFlags(), true);
- method.swap();
- argsCount = loadArgs(args);
- }
- @Override
- void consumeStack() {
- dynamicCall(2 + argsCount, getCallSiteFlags(), node.toString(false));
- }
- }.emit();
- return false;
- }
-
- @Override
- protected boolean enterDefault(final Node node) {
- new OptimisticOperation(callNode, resultBounds) {
- int argsCount;
- @Override
- void loadStack() {
- // Load up function.
- loadExpressionAsObject(function); //TODO, e.g. booleans can be used as functions
- method.loadUndefined(Type.OBJECT); // ScriptFunction will figure out the correct this when it sees CALLSITE_SCOPE
- argsCount = loadArgs(args);
- }
- @Override
- void consumeStack() {
- final int flags = getCallSiteFlags() | CALLSITE_SCOPE;
- dynamicCall(2 + argsCount, flags, node.toString(false));
- }
- }.emit();
- return false;
- }
- });
-
- return false;
- }
-
- /**
- * Returns the flags with optimistic flag and program point removed.
- * @param flags the flags that need optimism stripped from them.
- * @return flags without optimism
- */
- static int nonOptimisticFlags(final int flags) {
- return flags & ~(CALLSITE_OPTIMISTIC | -1 << CALLSITE_PROGRAM_POINT_SHIFT);
- }
-
- @Override
- public boolean enterContinueNode(final ContinueNode continueNode) {
- return enterJumpStatement(continueNode);
- }
-
- @Override
- public boolean enterEmptyNode(final EmptyNode emptyNode) {
- // Don't even record the line number, it's irrelevant as there's no code.
- return false;
- }
-
- @Override
- public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(expressionStatement);
-
- loadAndDiscard(expressionStatement.getExpression());
- assert method.getStackSize() == 0 : "stack not empty in " + expressionStatement;
-
- return false;
- }
-
- @Override
- public boolean enterBlockStatement(final BlockStatement blockStatement) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(blockStatement);
-
- blockStatement.getBlock().accept(this);
-
- return false;
- }
-
- @Override
- public boolean enterForNode(final ForNode forNode) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(forNode);
- if (forNode.isForInOrOf()) {
- enterForIn(forNode);
- } else {
- final Expression init = forNode.getInit();
- if (init != null) {
- loadAndDiscard(init);
- }
- enterForOrWhile(forNode, forNode.getModify());
- }
-
- return false;
- }
-
- private void enterForIn(final ForNode forNode) {
- loadExpression(forNode.getModify(), TypeBounds.OBJECT);
- if (forNode.isForEach()) {
- method.invoke(ScriptRuntime.TO_VALUE_ITERATOR);
- } else if (forNode.isForIn()) {
- method.invoke(ScriptRuntime.TO_PROPERTY_ITERATOR);
- } else if (forNode.isForOf()) {
- method.invoke(ScriptRuntime.TO_ES6_ITERATOR);
- } else {
- throw new IllegalArgumentException("Unexpected for node");
- }
- final Symbol iterSymbol = forNode.getIterator();
- final int iterSlot = iterSymbol.getSlot(Type.OBJECT);
- method.store(iterSymbol, ITERATOR_TYPE);
-
- method.beforeJoinPoint(forNode);
-
- final Label continueLabel = forNode.getContinueLabel();
- final Label breakLabel = forNode.getBreakLabel();
-
- method.label(continueLabel);
- method.load(ITERATOR_TYPE, iterSlot);
- method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "hasNext", boolean.class));
- final JoinPredecessorExpression test = forNode.getTest();
- final Block body = forNode.getBody();
- if(LocalVariableConversion.hasLiveConversion(test)) {
- final Label afterConversion = new Label("for_in_after_test_conv");
- method.ifne(afterConversion);
- method.beforeJoinPoint(test);
- method._goto(breakLabel);
- method.label(afterConversion);
- } else {
- method.ifeq(breakLabel);
- }
-
- new Store(forNode.getInit()) {
- @Override
- protected void storeNonDiscard() {
- // This expression is neither part of a discard, nor needs to be left on the stack after it was
- // stored, so we override storeNonDiscard to be a no-op.
- }
-
- @Override
- protected void evaluate() {
- new OptimisticOperation((Optimistic)forNode.getInit(), TypeBounds.UNBOUNDED) {
- @Override
- void loadStack() {
- method.load(ITERATOR_TYPE, iterSlot);
- }
-
- @Override
- void consumeStack() {
- method.invoke(interfaceCallNoLookup(ITERATOR_CLASS, "next", Object.class));
- convertOptimisticReturnValue();
- }
- }.emit();
- }
- }.store();
- body.accept(this);
-
- if (forNode.needsScopeCreator() && lc.getCurrentBlock().providesScopeCreator()) {
- // for-in loops with lexical declaration need a new scope for each iteration.
- final FieldObjectCreator creator = scopeObjectCreators.peek();
- assert creator != null;
- creator.createForInIterationScope(method);
- method.storeCompilerConstant(SCOPE);
- }
-
- if(method.isReachable()) {
- method._goto(continueLabel);
- }
- method.label(breakLabel);
- }
-
- /**
- * Initialize the slots in a frame to undefined.
- *
- * @param block block with local vars.
- */
- private void initLocals(final Block block) {
- lc.onEnterBlock(block);
-
- final boolean isFunctionBody = lc.isFunctionBody();
- final FunctionNode function = lc.getCurrentFunction();
- if (isFunctionBody) {
- initializeMethodParameters(function);
- if(!function.isVarArg()) {
- expandParameterSlots(function);
- }
- if (method.hasScope()) {
- if (function.needsParentScope()) {
- method.loadCompilerConstant(CALLEE);
- method.invoke(ScriptFunction.GET_SCOPE);
- } else {
- assert function.hasScopeBlock();
- method.loadNull();
- }
- method.storeCompilerConstant(SCOPE);
- }
- if (function.needsArguments()) {
- initArguments(function);
- }
- }
-
- /*
- * Determine if block needs scope, if not, just do initSymbols for this block.
- */
- if (block.needsScope()) {
- /*
- * Determine if function is varargs and consequently variables have to
- * be in the scope.
- */
- final boolean varsInScope = function.allVarsInScope();
-
- // TODO for LET we can do better: if *block* does not contain any eval/with, we don't need its vars in scope.
-
- final boolean hasArguments = function.needsArguments();
- final List> tuples = new ArrayList<>();
- final Iterator paramIter = function.getParameters().iterator();
- for (final Symbol symbol : block.getSymbols()) {
- if (symbol.isInternal() || symbol.isThis()) {
- continue;
- }
-
- if (symbol.isVar()) {
- assert !varsInScope || symbol.isScope();
- if (varsInScope || symbol.isScope()) {
- assert symbol.isScope() : "scope for " + symbol + " should have been set in Lower already " + function.getName();
- assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already" + function.getName();
-
- //this tuple will not be put fielded, as it has no value, just a symbol
- tuples.add(new MapTuple(symbol.getName(), symbol, null));
- } else {
- assert symbol.hasSlot() || symbol.slotCount() == 0 : symbol + " should have a slot only, no scope";
- }
- } else if (symbol.isParam() && (varsInScope || hasArguments || symbol.isScope())) {
- assert symbol.isScope() : "scope for " + symbol + " should have been set in AssignSymbols already " + function.getName() + " varsInScope="+varsInScope+" hasArguments="+hasArguments+" symbol.isScope()=" + symbol.isScope();
- assert !(hasArguments && symbol.hasSlot()) : "slot for " + symbol + " should have been removed in Lower already " + function.getName();
-
- final Type paramType;
- final Symbol paramSymbol;
-
- if (hasArguments) {
- assert !symbol.hasSlot() : "slot for " + symbol + " should have been removed in Lower already ";
- paramSymbol = null;
- paramType = null;
- } else {
- paramSymbol = symbol;
- // NOTE: We're relying on the fact here that Block.symbols is a LinkedHashMap, hence it will
- // return symbols in the order they were defined, and parameters are defined in the same order
- // they appear in the function. That's why we can have a single pass over the parameter list
- // with an iterator, always just scanning forward for the next parameter that matches the symbol
- // name.
- for(;;) {
- final IdentNode nextParam = paramIter.next();
- if(nextParam.getName().equals(symbol.getName())) {
- paramType = nextParam.getType();
- break;
- }
- }
- }
-
- tuples.add(new MapTuple(symbol.getName(), symbol, paramType, paramSymbol) {
- //this symbol will be put fielded, we can't initialize it as undefined with a known type
- @Override
- public Class getValueType() {
- if (!useDualFields() || value == null || paramType == null || paramType.isBoolean()) {
- return Object.class;
- }
- return paramType.getTypeClass();
- }
- });
- }
- }
-
- /*
- * Create a new object based on the symbols and values, generate
- * bootstrap code for object
- */
- final FieldObjectCreator creator = new FieldObjectCreator(this, tuples, true, hasArguments) {
- @Override
- protected void loadValue(final Symbol value, final Type type) {
- method.load(value, type);
- }
- };
- creator.makeObject(method);
- if (block.providesScopeCreator()) {
- scopeObjectCreators.push(creator);
- }
- // program function: merge scope into global
- if (isFunctionBody && function.isProgram()) {
- method.invoke(ScriptRuntime.MERGE_SCOPE);
- }
-
- method.storeCompilerConstant(SCOPE);
- if(!isFunctionBody) {
- // Function body doesn't need a try/catch to restore scope, as it'd be a dead store anyway. Allowing it
- // actually causes issues with UnwarrantedOptimismException handlers as ASM will sort this handler to
- // the top of the exception handler table, so it'll be triggered instead of the UOE handlers.
- final Label scopeEntryLabel = new Label("scope_entry");
- scopeEntryLabels.push(scopeEntryLabel);
- method.label(scopeEntryLabel);
- }
- } else if (isFunctionBody && function.isVarArg()) {
- // Since we don't have a scope, parameters didn't get assigned array indices by the FieldObjectCreator, so
- // we need to assign them separately here.
- int nextParam = 0;
- for (final IdentNode param : function.getParameters()) {
- param.getSymbol().setFieldIndex(nextParam++);
- }
- }
-
- // Debugging: print symbols? @see --print-symbols flag
- printSymbols(block, function, (isFunctionBody ? "Function " : "Block in ") + (function.getIdent() == null ? "" : function.getIdent().getName()));
- }
-
- /**
- * Incoming method parameters are always declared on method entry; declare them in the local variable table.
- * @param function function for which code is being generated.
- */
- private void initializeMethodParameters(final FunctionNode function) {
- final Label functionStart = new Label("fn_start");
- method.label(functionStart);
- int nextSlot = 0;
- if(function.needsCallee()) {
- initializeInternalFunctionParameter(CALLEE, function, functionStart, nextSlot++);
- }
- initializeInternalFunctionParameter(THIS, function, functionStart, nextSlot++);
- if(function.isVarArg()) {
- initializeInternalFunctionParameter(VARARGS, function, functionStart, nextSlot++);
- } else {
- for(final IdentNode param: function.getParameters()) {
- final Symbol symbol = param.getSymbol();
- if(symbol.isBytecodeLocal()) {
- method.initializeMethodParameter(symbol, param.getType(), functionStart);
- }
- }
- }
- }
-
- private void initializeInternalFunctionParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
- final Symbol symbol = initializeInternalFunctionOrSplitParameter(cc, fn, functionStart, slot);
- // Internal function params (:callee, this, and :varargs) are never expanded to multiple slots
- assert symbol.getFirstSlot() == slot;
- }
-
- private Symbol initializeInternalFunctionOrSplitParameter(final CompilerConstants cc, final FunctionNode fn, final Label functionStart, final int slot) {
- final Symbol symbol = fn.getBody().getExistingSymbol(cc.symbolName());
- final Type type = Type.typeFor(cc.type());
- method.initializeMethodParameter(symbol, type, functionStart);
- method.onLocalStore(type, slot);
- return symbol;
- }
-
- /**
- * Parameters come into the method packed into local variable slots next to each other. Nashorn on the other hand
- * can use 1-6 slots for a local variable depending on all the types it needs to store. When this method is invoked,
- * the symbols are already allocated such wider slots, but the values are still in tightly packed incoming slots,
- * and we need to spread them into their new locations.
- * @param function the function for which parameter-spreading code needs to be emitted
- */
- private void expandParameterSlots(final FunctionNode function) {
- final List parameters = function.getParameters();
- // Calculate the total number of incoming parameter slots
- int currentIncomingSlot = function.needsCallee() ? 2 : 1;
- for(final IdentNode parameter: parameters) {
- currentIncomingSlot += parameter.getType().getSlots();
- }
- // Starting from last parameter going backwards, move the parameter values into their new slots.
- for(int i = parameters.size(); i-- > 0;) {
- final IdentNode parameter = parameters.get(i);
- final Type parameterType = parameter.getType();
- final int typeWidth = parameterType.getSlots();
- currentIncomingSlot -= typeWidth;
- final Symbol symbol = parameter.getSymbol();
- final int slotCount = symbol.slotCount();
- assert slotCount > 0;
- // Scoped parameters must not hold more than one value
- assert symbol.isBytecodeLocal() || slotCount == typeWidth;
-
- // Mark it as having its value stored into it by the method invocation.
- method.onLocalStore(parameterType, currentIncomingSlot);
- if(currentIncomingSlot != symbol.getSlot(parameterType)) {
- method.load(parameterType, currentIncomingSlot);
- method.store(symbol, parameterType);
- }
- }
- }
-
- private void initArguments(final FunctionNode function) {
- method.loadCompilerConstant(VARARGS);
- if (function.needsCallee()) {
- method.loadCompilerConstant(CALLEE);
- } else {
- // If function is strict mode, "arguments.callee" is not populated, so we don't necessarily need the
- // caller.
- assert function.isStrict();
- method.loadNull();
- }
- method.load(function.getParameters().size());
- globalAllocateArguments();
- method.storeCompilerConstant(ARGUMENTS);
- }
-
- private boolean skipFunction(final FunctionNode functionNode) {
- final ScriptEnvironment env = compiler.getScriptEnvironment();
- final boolean lazy = env._lazy_compilation;
- final boolean onDemand = compiler.isOnDemandCompilation();
-
- // If this is on-demand or lazy compilation, don't compile a nested (not topmost) function.
- if((onDemand || lazy) && lc.getOutermostFunction() != functionNode) {
- return true;
- }
-
- // If lazy compiling with optimistic types, don't compile the program eagerly either. It will soon be
- // invalidated anyway. In presence of a class cache, this further means that an obsoleted program version
- // lingers around. Also, currently loading previously persisted optimistic types information only works if
- // we're on-demand compiling a function, so with this strategy the :program method can also have the warmup
- // benefit of using previously persisted types.
- //
- // NOTE that this means the first compiled class will effectively just have a :createProgramFunction method, and
- // the RecompilableScriptFunctionData (RSFD) object in its constants array. It won't even have the :program
- // method. This is by design. It does mean that we're wasting one compiler execution (and we could minimize this
- // by just running it up to scope depth calculation, which creates the RSFDs and then this limited codegen).
- // We could emit an initial separate compile unit with the initial version of :program in it to better utilize
- // the compilation pipeline, but that would need more invasive changes, as currently the assumption that
- // :program is emitted into the first compilation unit of the function lives in many places.
- return !onDemand && lazy && env._optimistic_types && functionNode.isProgram();
- }
-
- @Override
- public boolean enterFunctionNode(final FunctionNode functionNode) {
- if (skipFunction(functionNode)) {
- // In case we are not generating code for the function, we must create or retrieve the function object and
- // load it on the stack here.
- newFunctionObject(functionNode, false);
- return false;
- }
-
- final String fnName = functionNode.getName();
-
- // NOTE: we only emit the method for a function with the given name once. We can have multiple functions with
- // the same name as a result of inlining finally blocks. However, in the future -- with type specialization,
- // notably -- we might need to check for both name *and* signature. Of course, even that might not be
- // sufficient; the function might have a code dependency on the type of the variables in its enclosing scopes,
- // and the type of such a variable can be different in catch and finally blocks. So, in the future we will have
- // to decide to either generate a unique method for each inlined copy of the function, maybe figure out its
- // exact type closure and deduplicate based on that, or just decide that functions in finally blocks aren't
- // worth it, and generate one method with most generic type closure.
- if (!emittedMethods.contains(fnName)) {
- log.info("=== BEGIN ", fnName);
-
- assert functionNode.getCompileUnit() != null : "no compile unit for " + fnName + " " + Debug.id(functionNode);
- unit = lc.pushCompileUnit(functionNode.getCompileUnit());
- assert lc.hasCompileUnits();
-
- final ClassEmitter classEmitter = unit.getClassEmitter();
- pushMethodEmitter(isRestOf() ? classEmitter.restOfMethod(functionNode) : classEmitter.method(functionNode));
- method.setPreventUndefinedLoad();
- if(useOptimisticTypes()) {
- lc.pushUnwarrantedOptimismHandlers();
- }
-
- // new method - reset last line number
- lastLineNumber = -1;
-
- method.begin();
-
- if (isRestOf()) {
- assert continuationInfo == null;
- continuationInfo = new ContinuationInfo();
- method.gotoLoopStart(continuationInfo.getHandlerLabel());
- }
- }
-
- return true;
- }
-
- private void pushMethodEmitter(final MethodEmitter newMethod) {
- method = lc.pushMethodEmitter(newMethod);
- catchLabels.push(METHOD_BOUNDARY);
- }
-
- private void popMethodEmitter() {
- method = lc.popMethodEmitter(method);
- assert catchLabels.peek() == METHOD_BOUNDARY;
- catchLabels.pop();
- }
-
- @Override
- public Node leaveFunctionNode(final FunctionNode functionNode) {
- try {
- final boolean markOptimistic;
- if (emittedMethods.add(functionNode.getName())) {
- markOptimistic = generateUnwarrantedOptimismExceptionHandlers(functionNode);
- generateContinuationHandler();
- method.end(); // wrap up this method
- unit = lc.popCompileUnit(functionNode.getCompileUnit());
- popMethodEmitter();
- log.info("=== END ", functionNode.getName());
- } else {
- markOptimistic = false;
- }
-
- FunctionNode newFunctionNode = functionNode;
- if (markOptimistic) {
- newFunctionNode = newFunctionNode.setFlag(lc, FunctionNode.IS_DEOPTIMIZABLE);
- }
-
- newFunctionObject(newFunctionNode, true);
- return newFunctionNode;
- } catch (final Throwable t) {
- Context.printStackTrace(t);
- final VerifyError e = new VerifyError("Code generation bug in \"" + functionNode.getName() + "\": likely stack misaligned: " + t + " " + functionNode.getSource().getName());
- e.initCause(t);
- throw e;
- }
- }
-
- @Override
- public boolean enterIfNode(final IfNode ifNode) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(ifNode);
-
- final Expression test = ifNode.getTest();
- final Block pass = ifNode.getPass();
- final Block fail = ifNode.getFail();
-
- if (Expression.isAlwaysTrue(test)) {
- loadAndDiscard(test);
- pass.accept(this);
- return false;
- } else if (Expression.isAlwaysFalse(test)) {
- loadAndDiscard(test);
- if (fail != null) {
- fail.accept(this);
- }
- return false;
- }
-
- final boolean hasFailConversion = LocalVariableConversion.hasLiveConversion(ifNode);
-
- final Label failLabel = new Label("if_fail");
- final Label afterLabel = (fail == null && !hasFailConversion) ? null : new Label("if_done");
-
- emitBranch(test, failLabel, false);
-
- pass.accept(this);
- if(method.isReachable() && afterLabel != null) {
- method._goto(afterLabel); //don't fallthru to fail block
- }
- method.label(failLabel);
-
- if (fail != null) {
- fail.accept(this);
- } else if(hasFailConversion) {
- method.beforeJoinPoint(ifNode);
- }
-
- if(afterLabel != null && afterLabel.isReachable()) {
- method.label(afterLabel);
- }
-
- return false;
- }
-
- private void emitBranch(final Expression test, final Label label, final boolean jumpWhenTrue) {
- new BranchOptimizer(this, method).execute(test, label, jumpWhenTrue);
- }
-
- private void enterStatement(final Statement statement) {
- lineNumber(statement);
- }
-
- private void lineNumber(final Statement statement) {
- lineNumber(statement.getLineNumber());
- }
-
- private void lineNumber(final int lineNumber) {
- if (lineNumber != lastLineNumber && lineNumber != Node.NO_LINE_NUMBER) {
- method.lineNumber(lineNumber);
- lastLineNumber = lineNumber;
- }
- }
-
- int getLastLineNumber() {
- return lastLineNumber;
- }
-
- /**
- * Load a list of nodes as an array of a specific type
- * The array will contain the visited nodes.
- *
- * @param arrayLiteralNode the array of contents
- * @param arrayType the type of the array, e.g. ARRAY_NUMBER or ARRAY_OBJECT
- */
- private void loadArray(final ArrayLiteralNode arrayLiteralNode, final ArrayType arrayType) {
- assert arrayType == Type.INT_ARRAY || arrayType == Type.NUMBER_ARRAY || arrayType == Type.OBJECT_ARRAY;
-
- final Expression[] nodes = arrayLiteralNode.getValue();
- final Object presets = arrayLiteralNode.getPresets();
- final int[] postsets = arrayLiteralNode.getPostsets();
- final List ranges = arrayLiteralNode.getSplitRanges();
-
- loadConstant(presets);
-
- final Type elementType = arrayType.getElementType();
-
- if (ranges != null) {
-
- loadSplitLiteral(new SplitLiteralCreator() {
- @Override
- public void populateRange(final MethodEmitter method, final Type type, final int slot, final int start, final int end) {
- for (int i = start; i < end; i++) {
- method.load(type, slot);
- storeElement(nodes, elementType, postsets[i]);
- }
- method.load(type, slot);
- }
- }, ranges, arrayType);
-
- return;
- }
-
- if(postsets.length > 0) {
- final int arraySlot = method.getUsedSlotsWithLiveTemporaries();
- method.storeTemp(arrayType, arraySlot);
- for (final int postset : postsets) {
- method.load(arrayType, arraySlot);
- storeElement(nodes, elementType, postset);
- }
- method.load(arrayType, arraySlot);
- }
- }
-
- private void storeElement(final Expression[] nodes, final Type elementType, final int index) {
- method.load(index);
-
- final Expression element = nodes[index];
-
- if (element == null) {
- method.loadEmpty(elementType);
- } else {
- loadExpressionAsType(element, elementType);
- }
-
- method.arraystore();
- }
-
- private MethodEmitter loadArgsArray(final List args) {
- final Object[] array = new Object[args.size()];
- loadConstant(array);
-
- for (int i = 0; i < args.size(); i++) {
- method.dup();
- method.load(i);
- loadExpression(args.get(i), TypeBounds.OBJECT); // variable arity methods always take objects
- method.arraystore();
- }
-
- return method;
- }
-
- /**
- * Load a constant from the constant array. This is only public to be callable from the objects
- * subpackage. Do not call directly.
- *
- * @param string string to load
- */
- void loadConstant(final String string) {
- final String unitClassName = unit.getUnitClassName();
- final ClassEmitter classEmitter = unit.getClassEmitter();
- final int index = compiler.getConstantData().add(string);
-
- method.load(index);
- method.invokestatic(unitClassName, GET_STRING.symbolName(), methodDescriptor(String.class, int.class));
- classEmitter.needGetConstantMethod(String.class);
- }
-
- /**
- * Load a constant from the constant array. This is only public to be callable from the objects
- * subpackage. Do not call directly.
- *
- * @param object object to load
- */
- void loadConstant(final Object object) {
- loadConstant(object, unit, method);
- }
-
- private void loadConstant(final Object object, final CompileUnit compileUnit, final MethodEmitter methodEmitter) {
- final String unitClassName = compileUnit.getUnitClassName();
- final ClassEmitter classEmitter = compileUnit.getClassEmitter();
- final int index = compiler.getConstantData().add(object);
- final Class cls = object.getClass();
-
- if (cls == PropertyMap.class) {
- methodEmitter.load(index);
- methodEmitter.invokestatic(unitClassName, GET_MAP.symbolName(), methodDescriptor(PropertyMap.class, int.class));
- classEmitter.needGetConstantMethod(PropertyMap.class);
- } else if (cls.isArray()) {
- methodEmitter.load(index);
- final String methodName = ClassEmitter.getArrayMethodName(cls);
- methodEmitter.invokestatic(unitClassName, methodName, methodDescriptor(cls, int.class));
- classEmitter.needGetConstantMethod(cls);
- } else {
- methodEmitter.loadConstants().load(index).arrayload();
- if (object instanceof ArrayData) {
- methodEmitter.checkcast(ArrayData.class);
- methodEmitter.invoke(virtualCallNoLookup(ArrayData.class, "copy", ArrayData.class));
- } else if (cls != Object.class) {
- methodEmitter.checkcast(cls);
- }
- }
- }
-
- private void loadConstantsAndIndex(final Object object, final MethodEmitter methodEmitter) {
- methodEmitter.loadConstants().load(compiler.getConstantData().add(object));
- }
-
- // literal values
- private void loadLiteral(final LiteralNode node, final TypeBounds resultBounds) {
- final Object value = node.getValue();
-
- if (value == null) {
- method.loadNull();
- } else if (value instanceof Undefined) {
- method.loadUndefined(resultBounds.within(Type.OBJECT));
- } else if (value instanceof String) {
- final String string = (String)value;
-
- if (string.length() > MethodEmitter.LARGE_STRING_THRESHOLD / 3) { // 3 == max bytes per encoded char
- loadConstant(string);
- } else {
- method.load(string);
- }
- } else if (value instanceof RegexToken) {
- loadRegex((RegexToken)value);
- } else if (value instanceof Boolean) {
- method.load((Boolean)value);
- } else if (value instanceof Integer) {
- if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
- method.load((Integer)value);
- method.convert(Type.OBJECT);
- } else if(!resultBounds.canBeNarrowerThan(Type.NUMBER)) {
- method.load(((Integer)value).doubleValue());
- } else {
- method.load((Integer)value);
- }
- } else if (value instanceof Double) {
- if(!resultBounds.canBeNarrowerThan(Type.OBJECT)) {
- method.load((Double)value);
- method.convert(Type.OBJECT);
- } else {
- method.load((Double)value);
- }
- } else if (node instanceof ArrayLiteralNode) {
- final ArrayLiteralNode arrayLiteral = (ArrayLiteralNode)node;
- final ArrayType atype = arrayLiteral.getArrayType();
- loadArray(arrayLiteral, atype);
- globalAllocateArray(atype);
- } else {
- throw new UnsupportedOperationException("Unknown literal for " + node.getClass() + " " + value.getClass() + " " + value);
- }
- }
-
- private MethodEmitter loadRegexToken(final RegexToken value) {
- method.load(value.getExpression());
- method.load(value.getOptions());
- return globalNewRegExp();
- }
-
- private MethodEmitter loadRegex(final RegexToken regexToken) {
- if (regexFieldCount > MAX_REGEX_FIELDS) {
- return loadRegexToken(regexToken);
- }
- // emit field
- final String regexName = lc.getCurrentFunction().uniqueName(REGEX_PREFIX.symbolName());
- final ClassEmitter classEmitter = unit.getClassEmitter();
-
- classEmitter.field(EnumSet.of(PRIVATE, STATIC), regexName, Object.class);
- regexFieldCount++;
-
- // get field, if null create new regex, finally clone regex object
- method.getStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
- method.dup();
- final Label cachedLabel = new Label("cached");
- method.ifnonnull(cachedLabel);
-
- method.pop();
- loadRegexToken(regexToken);
- method.dup();
- method.putStatic(unit.getUnitClassName(), regexName, typeDescriptor(Object.class));
-
- method.label(cachedLabel);
- globalRegExpCopy();
-
- return method;
- }
-
- /**
- * Check if a property value contains a particular program point
- * @param value value
- * @param pp program point
- * @return true if it's there.
- */
- private static boolean propertyValueContains(final Expression value, final int pp) {
- return new Supplier() {
- boolean contains;
-
- @Override
- public Boolean get() {
- value.accept(new SimpleNodeVisitor() {
- @Override
- public boolean enterFunctionNode(final FunctionNode functionNode) {
- return false;
- }
-
- @Override
- public boolean enterDefault(final Node node) {
- if (contains) {
- return false;
- }
- if (node instanceof Optimistic && ((Optimistic)node).getProgramPoint() == pp) {
- contains = true;
- return false;
- }
- return true;
- }
- });
-
- return contains;
- }
- }.get();
- }
-
- private void loadObjectNode(final ObjectNode objectNode) {
- final List elements = objectNode.getElements();
-
- final List> tuples = new ArrayList<>();
- // List below will contain getter/setter properties and properties with computed keys (ES6)
- final List specialProperties = new ArrayList<>();
- final int ccp = getCurrentContinuationEntryPoint();
- final List ranges = objectNode.getSplitRanges();
-
- Expression protoNode = null;
- boolean restOfProperty = false;
-
- for (final PropertyNode propertyNode : elements) {
- final Expression value = propertyNode.getValue();
- final String key = propertyNode.getKeyName();
- final boolean isComputedOrAccessor = propertyNode.isComputed() || value == null;
-
- // Just use a pseudo-symbol. We just need something non null; use the name and zero flags.
- final Symbol symbol = isComputedOrAccessor ? null : new Symbol(key, 0);
-
- if (isComputedOrAccessor) {
- // Properties with computed names or getter/setters need special handling.
- specialProperties.add(propertyNode);
- } else if (propertyNode.getKey() instanceof IdentNode &&
- key.equals(ScriptObject.PROTO_PROPERTY_NAME)) {
- // ES6 draft compliant __proto__ inside object literal
- // Identifier key and name is __proto__
- protoNode = value;
- continue;
- }
-
- restOfProperty |=
- value != null &&
- isValid(ccp) &&
- propertyValueContains(value, ccp);
-
- //for literals, a value of null means object type, i.e. the value null or getter setter function
- //(I think)
- final Class valueType = (!useDualFields() || isComputedOrAccessor || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass();
- tuples.add(new MapTuple(key, symbol, Type.typeFor(valueType), value) {
- @Override
- public Class getValueType() {
- return type.getTypeClass();
- }
- });
- }
-
- final ObjectCreator oc;
- if (elements.size() > OBJECT_SPILL_THRESHOLD) {
- oc = new SpillObjectCreator(this, tuples);
- } else {
- oc = new FieldObjectCreator(this, tuples) {
- @Override
- protected void loadValue(final Expression node, final Type type) {
- // Use generic type in order to avoid conversion between object types
- loadExpressionAsType(node, Type.generic(type));
- }};
- }
-
- if (ranges != null) {
- oc.createObject(method);
- loadSplitLiteral(oc, ranges, Type.typeFor(oc.getAllocatorClass()));
- } else {
- oc.makeObject(method);
- }
-
- //if this is a rest of method and our continuation point was found as one of the values
- //in the properties above, we need to reset the map to oc.getMap() in the continuation
- //handler
- if (restOfProperty) {
- final ContinuationInfo ci = getContinuationInfo();
- ci.setObjectLiteralMap(method.getStackSize(), oc.getMap());
- }
-
- method.dup();
- if (protoNode != null) {
- loadExpressionAsObject(protoNode);
- // take care of { __proto__: 34 } or some such!
- method.convert(Type.OBJECT);
- method.invoke(ScriptObject.SET_PROTO_FROM_LITERAL);
- } else {
- method.invoke(ScriptObject.SET_GLOBAL_OBJECT_PROTO);
- }
-
- for (final PropertyNode propertyNode : specialProperties) {
-
- method.dup();
-
- if (propertyNode.isComputed()) {
- assert propertyNode.getKeyName() == null;
- loadExpressionAsObject(propertyNode.getKey());
- } else {
- method.loadKey(propertyNode.getKey());
- }
-
- if (propertyNode.getValue() != null) {
- loadExpressionAsObject(propertyNode.getValue());
- method.load(0);
- method.invoke(ScriptObject.GENERIC_SET);
- } else {
- final FunctionNode getter = propertyNode.getGetter();
- final FunctionNode setter = propertyNode.getSetter();
-
- assert getter != null || setter != null;
-
- if (getter == null) {
- method.loadNull();
- } else {
- getter.accept(this);
- }
-
- if (setter == null) {
- method.loadNull();
- } else {
- setter.accept(this);
- }
-
- method.invoke(ScriptObject.SET_USER_ACCESSORS);
- }
- }
- }
-
- @Override
- public boolean enterReturnNode(final ReturnNode returnNode) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(returnNode);
-
- final Type returnType = lc.getCurrentFunction().getReturnType();
-
- final Expression expression = returnNode.getExpression();
- if (expression != null) {
- loadExpressionUnbounded(expression);
- } else {
- method.loadUndefined(returnType);
- }
-
- method._return(returnType);
-
- return false;
- }
-
- private boolean undefinedCheck(final RuntimeNode runtimeNode, final List args) {
- final Request request = runtimeNode.getRequest();
-
- if (!Request.isUndefinedCheck(request)) {
- return false;
- }
-
- final Expression lhs = args.get(0);
- final Expression rhs = args.get(1);
-
- final Symbol lhsSymbol = lhs instanceof IdentNode ? ((IdentNode)lhs).getSymbol() : null;
- final Symbol rhsSymbol = rhs instanceof IdentNode ? ((IdentNode)rhs).getSymbol() : null;
- // One must be a "undefined" identifier, otherwise we can't get here
- assert lhsSymbol != null || rhsSymbol != null;
-
- final Symbol undefinedSymbol;
- if (isUndefinedSymbol(lhsSymbol)) {
- undefinedSymbol = lhsSymbol;
- } else {
- assert isUndefinedSymbol(rhsSymbol);
- undefinedSymbol = rhsSymbol;
- }
-
- assert undefinedSymbol != null; //remove warning
- if (!undefinedSymbol.isScope()) {
- return false; //disallow undefined as local var or parameter
- }
-
- if (lhsSymbol == undefinedSymbol && lhs.getType().isPrimitive()) {
- //we load the undefined first. never mind, because this will deoptimize anyway
- return false;
- }
-
- if(containsOptimisticExpression(lhs)) {
- // Any optimistic expression within lhs could be deoptimized and trigger a rest-of compilation.
- // We must not perform undefined check specialization for them, as then we'd violate the basic rule of
- // "Thou shalt not alter the stack shape between a deoptimized method and any of its (transitive) rest-ofs."
- return false;
- }
-
- //make sure that undefined has not been overridden or scoped as a local var
- //between us and global
- if (!compiler.isGlobalSymbol(lc.getCurrentFunction(), "undefined")) {
- return false;
- }
-
- final boolean isUndefinedCheck = request == Request.IS_UNDEFINED;
- final Expression expr = undefinedSymbol == lhsSymbol ? rhs : lhs;
- if (expr.getType().isPrimitive()) {
- loadAndDiscard(expr); //throw away lhs, but it still needs to be evaluated for side effects, even if not in scope, as it can be optimistic
- method.load(!isUndefinedCheck);
- } else {
- final Label checkTrue = new Label("ud_check_true");
- final Label end = new Label("end");
- loadExpressionAsObject(expr);
- method.loadUndefined(Type.OBJECT);
- method.if_acmpeq(checkTrue);
- method.load(!isUndefinedCheck);
- method._goto(end);
- method.label(checkTrue);
- method.load(isUndefinedCheck);
- method.label(end);
- }
-
- return true;
- }
-
- private static boolean isUndefinedSymbol(final Symbol symbol) {
- return symbol != null && "undefined".equals(symbol.getName());
- }
-
- private static boolean isNullLiteral(final Node node) {
- return node instanceof LiteralNode && ((LiteralNode) node).isNull();
- }
-
- private boolean nullCheck(final RuntimeNode runtimeNode, final List args) {
- final Request request = runtimeNode.getRequest();
-
- if (!Request.isEQ(request) && !Request.isNE(request)) {
- return false;
- }
-
- assert args.size() == 2 : "EQ or NE or TYPEOF need two args";
-
- Expression lhs = args.get(0);
- Expression rhs = args.get(1);
-
- if (isNullLiteral(lhs)) {
- final Expression tmp = lhs;
- lhs = rhs;
- rhs = tmp;
- }
-
- if (!isNullLiteral(rhs)) {
- return false;
- }
-
- if (!lhs.getType().isObject()) {
- return false;
- }
-
- if(containsOptimisticExpression(lhs)) {
- // Any optimistic expression within lhs could be deoptimized and trigger a rest-of compilation.
- // We must not perform null check specialization for them, as then we'd no longer be loading aconst_null
- // on stack and thus violate the basic rule of "Thou shalt not alter the stack shape between a deoptimized
- // method and any of its (transitive) rest-ofs."
- // NOTE also that if we had a representation for well-known constants (e.g. null, 0, 1, -1, etc.) in
- // Label$Stack.localLoads then this wouldn't be an issue, as we would never (somewhat ridiculously)
- // allocate a temporary local to hold the result of aconst_null before attempting an optimistic
- // operation.
- return false;
- }
-
- // this is a null literal check, so if there is implicit coercion
- // involved like {D}x=null, we will fail - this is very rare
- final Label trueLabel = new Label("trueLabel");
- final Label falseLabel = new Label("falseLabel");
- final Label endLabel = new Label("end");
-
- loadExpressionUnbounded(lhs); //lhs
- final Label popLabel;
- if (!Request.isStrict(request)) {
- method.dup(); //lhs lhs
- popLabel = new Label("pop");
- } else {
- popLabel = null;
- }
-
- if (Request.isEQ(request)) {
- method.ifnull(!Request.isStrict(request) ? popLabel : trueLabel);
- if (!Request.isStrict(request)) {
- method.loadUndefined(Type.OBJECT);
- method.if_acmpeq(trueLabel);
- }
- method.label(falseLabel);
- method.load(false);
- method._goto(endLabel);
- if (!Request.isStrict(request)) {
- method.label(popLabel);
- method.pop();
- }
- method.label(trueLabel);
- method.load(true);
- method.label(endLabel);
- } else if (Request.isNE(request)) {
- method.ifnull(!Request.isStrict(request) ? popLabel : falseLabel);
- if (!Request.isStrict(request)) {
- method.loadUndefined(Type.OBJECT);
- method.if_acmpeq(falseLabel);
- }
- method.label(trueLabel);
- method.load(true);
- method._goto(endLabel);
- if (!Request.isStrict(request)) {
- method.label(popLabel);
- method.pop();
- }
- method.label(falseLabel);
- method.load(false);
- method.label(endLabel);
- }
-
- assert runtimeNode.getType().isBoolean();
- method.convert(runtimeNode.getType());
-
- return true;
- }
-
- /**
- * Is this expression or any of its subexpressions optimistic? This includes formerly optimistic
- * expressions that have been deoptimized in a subsequent compilation.
- *
- * @param rootExpr the expression being tested
- * @return true if the expression or any of its subexpressions is optimistic in the current compilation.
- */
- private boolean containsOptimisticExpression(final Expression rootExpr) {
- if(!useOptimisticTypes()) {
- return false;
- }
- return new Supplier() {
- boolean contains;
- @Override
- public Boolean get() {
- rootExpr.accept(new SimpleNodeVisitor() {
- @Override
- public boolean enterFunctionNode(final FunctionNode functionNode) {
- return false;
- }
- @Override
- public boolean enterDefault(final Node node) {
- if(!contains && node instanceof Optimistic) {
- final int pp = ((Optimistic)node).getProgramPoint();
- contains = isValid(pp);
- }
- return !contains;
- }
- });
- return contains;
- }
- }.get();
- }
-
- private void loadRuntimeNode(final RuntimeNode runtimeNode) {
- final List args = new ArrayList<>(runtimeNode.getArgs());
- if (nullCheck(runtimeNode, args)) {
- return;
- } else if(undefinedCheck(runtimeNode, args)) {
- return;
- }
- // Revert a false undefined check to a strict equality check
- final RuntimeNode newRuntimeNode;
- final Request request = runtimeNode.getRequest();
- if (Request.isUndefinedCheck(request)) {
- newRuntimeNode = runtimeNode.setRequest(request == Request.IS_UNDEFINED ? Request.EQ_STRICT : Request.NE_STRICT);
- } else {
- newRuntimeNode = runtimeNode;
- }
-
- for (final Expression arg : args) {
- loadExpression(arg, TypeBounds.OBJECT);
- }
-
- method.invokestatic(
- CompilerConstants.className(ScriptRuntime.class),
- newRuntimeNode.getRequest().toString(),
- new FunctionSignature(
- false,
- false,
- newRuntimeNode.getType(),
- args.size()).toString());
-
- method.convert(newRuntimeNode.getType());
- }
-
- private void defineCommonSplitMethodParameters() {
- defineSplitMethodParameter(0, CALLEE);
- defineSplitMethodParameter(1, THIS);
- defineSplitMethodParameter(2, SCOPE);
- }
-
- private void defineSplitMethodParameter(final int slot, final CompilerConstants cc) {
- defineSplitMethodParameter(slot, Type.typeFor(cc.type()));
- }
-
- private void defineSplitMethodParameter(final int slot, final Type type) {
- method.defineBlockLocalVariable(slot, slot + type.getSlots());
- method.onLocalStore(type, slot);
- }
-
- private void loadSplitLiteral(final SplitLiteralCreator creator, final List ranges, final Type literalType) {
- assert ranges != null;
-
- // final Type literalType = Type.typeFor(literalClass);
- final MethodEmitter savedMethod = method;
- final FunctionNode currentFunction = lc.getCurrentFunction();
-
- for (final Splittable.SplitRange splitRange : ranges) {
- unit = lc.pushCompileUnit(splitRange.getCompileUnit());
-
- assert unit != null;
- final String className = unit.getUnitClassName();
- final String name = currentFunction.uniqueName(SPLIT_PREFIX.symbolName());
- final Class clazz = literalType.getTypeClass();
- final String signature = methodDescriptor(clazz, ScriptFunction.class, Object.class, ScriptObject.class, clazz);
-
- pushMethodEmitter(unit.getClassEmitter().method(EnumSet.of(Flag.PUBLIC, Flag.STATIC), name, signature));
-
- method.setFunctionNode(currentFunction);
- method.begin();
-
- defineCommonSplitMethodParameters();
- defineSplitMethodParameter(CompilerConstants.SPLIT_ARRAY_ARG.slot(), literalType);
-
- // NOTE: when this is no longer needed, SplitIntoFunctions will no longer have to add IS_SPLIT
- // to synthetic functions, and FunctionNode.needsCallee() will no longer need to test for isSplit().
- final int literalSlot = fixScopeSlot(currentFunction, 3);
-
- lc.enterSplitLiteral();
-
- creator.populateRange(method, literalType, literalSlot, splitRange.getLow(), splitRange.getHigh());
-
- method._return();
- lc.exitSplitLiteral();
- method.end();
- lc.releaseSlots();
- popMethodEmitter();
-
- assert method == savedMethod;
- method.loadCompilerConstant(CALLEE).swap();
- method.loadCompilerConstant(THIS).swap();
- method.loadCompilerConstant(SCOPE).swap();
- method.invokestatic(className, name, signature);
-
- unit = lc.popCompileUnit(unit);
- }
- }
-
- private int fixScopeSlot(final FunctionNode functionNode, final int extraSlot) {
- // TODO hack to move the scope to the expected slot (needed because split methods reuse the same slots as the root method)
- final int actualScopeSlot = functionNode.compilerConstant(SCOPE).getSlot(SCOPE_TYPE);
- final int defaultScopeSlot = SCOPE.slot();
- int newExtraSlot = extraSlot;
- if (actualScopeSlot != defaultScopeSlot) {
- if (actualScopeSlot == extraSlot) {
- newExtraSlot = extraSlot + 1;
- method.defineBlockLocalVariable(newExtraSlot, newExtraSlot + 1);
- method.load(Type.OBJECT, extraSlot);
- method.storeHidden(Type.OBJECT, newExtraSlot);
- } else {
- method.defineBlockLocalVariable(actualScopeSlot, actualScopeSlot + 1);
- }
- method.load(SCOPE_TYPE, defaultScopeSlot);
- method.storeCompilerConstant(SCOPE);
- }
- return newExtraSlot;
- }
-
- @Override
- public boolean enterSplitReturn(final SplitReturn splitReturn) {
- if (method.isReachable()) {
- method.loadUndefined(lc.getCurrentFunction().getReturnType())._return();
- }
- return false;
- }
-
- @Override
- public boolean enterSetSplitState(final SetSplitState setSplitState) {
- if (method.isReachable()) {
- method.setSplitState(setSplitState.getState());
- }
- return false;
- }
-
- @Override
- public boolean enterSwitchNode(final SwitchNode switchNode) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(switchNode);
-
- final Expression expression = switchNode.getExpression();
- final List cases = switchNode.getCases();
-
- if (cases.isEmpty()) {
- // still evaluate expression for side-effects.
- loadAndDiscard(expression);
- return false;
- }
-
- final CaseNode defaultCase = switchNode.getDefaultCase();
- final Label breakLabel = switchNode.getBreakLabel();
- final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
-
- if (defaultCase != null && cases.size() == 1) {
- // default case only
- assert cases.get(0) == defaultCase;
- loadAndDiscard(expression);
- defaultCase.getBody().accept(this);
- method.breakLabel(breakLabel, liveLocalsOnBreak);
- return false;
- }
-
- // NOTE: it can still change in the tableswitch/lookupswitch case if there's no default case
- // but we need to add a synthetic default case for local variable conversions
- Label defaultLabel = defaultCase != null ? defaultCase.getEntry() : breakLabel;
- final boolean hasSkipConversion = LocalVariableConversion.hasLiveConversion(switchNode);
-
- if (switchNode.isUniqueInteger()) {
- // Tree for sorting values.
- final TreeMap tree = new TreeMap<>();
-
- // Build up sorted tree.
- for (final CaseNode caseNode : cases) {
- final Node test = caseNode.getTest();
-
- if (test != null) {
- final Integer value = (Integer)((LiteralNode)test).getValue();
- final Label entry = caseNode.getEntry();
-
- // Take first duplicate.
- if (!tree.containsKey(value)) {
- tree.put(value, entry);
- }
- }
- }
-
- // Copy values and labels to arrays.
- final int size = tree.size();
- final Integer[] values = tree.keySet().toArray(new Integer[0]);
- final Label[] labels = tree.values().toArray(new Label[0]);
-
- // Discern low, high and range.
- final int lo = values[0];
- final int hi = values[size - 1];
- final long range = (long)hi - (long)lo + 1;
-
- // Find an unused value for default.
- int deflt = Integer.MIN_VALUE;
- for (final int value : values) {
- if (deflt == value) {
- deflt++;
- } else if (deflt < value) {
- break;
- }
- }
-
- // Load switch expression.
- loadExpressionUnbounded(expression);
- final Type type = expression.getType();
-
- // If expression not int see if we can convert, if not use deflt to trigger default.
- if (!type.isInteger()) {
- method.load(deflt);
- final Class exprClass = type.getTypeClass();
- method.invoke(staticCallNoLookup(ScriptRuntime.class, "switchTagAsInt", int.class, exprClass.isPrimitive()? exprClass : Object.class, int.class));
- }
-
- if(hasSkipConversion) {
- assert defaultLabel == breakLabel;
- defaultLabel = new Label("switch_skip");
- }
- // TABLESWITCH needs (range + 3) 32-bit values; LOOKUPSWITCH needs ((size * 2) + 2). Choose the one with
- // smaller representation, favor TABLESWITCH when they're equal size.
- if (range + 1 <= (size * 2) && range <= Integer.MAX_VALUE) {
- final Label[] table = new Label[(int)range];
- Arrays.fill(table, defaultLabel);
- for (int i = 0; i < size; i++) {
- final int value = values[i];
- table[value - lo] = labels[i];
- }
-
- method.tableswitch(lo, hi, defaultLabel, table);
- } else {
- final int[] ints = new int[size];
- for (int i = 0; i < size; i++) {
- ints[i] = values[i];
- }
-
- method.lookupswitch(defaultLabel, ints, labels);
- }
- // This is a synthetic "default case" used in absence of actual default case, created if we need to apply
- // local variable conversions if neither case is taken.
- if(hasSkipConversion) {
- method.label(defaultLabel);
- method.beforeJoinPoint(switchNode);
- method._goto(breakLabel);
- }
- } else {
- final Symbol tagSymbol = switchNode.getTag();
- // TODO: we could have non-object tag
- final int tagSlot = tagSymbol.getSlot(Type.OBJECT);
- loadExpressionAsObject(expression);
- method.store(tagSymbol, Type.OBJECT);
-
- for (final CaseNode caseNode : cases) {
- final Expression test = caseNode.getTest();
-
- if (test != null) {
- method.load(Type.OBJECT, tagSlot);
- loadExpressionAsObject(test);
- method.invoke(ScriptRuntime.EQ_STRICT);
- method.ifne(caseNode.getEntry());
- }
- }
-
- if (defaultCase != null) {
- method._goto(defaultLabel);
- } else {
- method.beforeJoinPoint(switchNode);
- method._goto(breakLabel);
- }
- }
-
- // First case is only reachable through jump
- assert !method.isReachable();
-
- for (final CaseNode caseNode : cases) {
- final Label fallThroughLabel;
- if(caseNode.getLocalVariableConversion() != null && method.isReachable()) {
- fallThroughLabel = new Label("fallthrough");
- method._goto(fallThroughLabel);
- } else {
- fallThroughLabel = null;
- }
- method.label(caseNode.getEntry());
- method.beforeJoinPoint(caseNode);
- if(fallThroughLabel != null) {
- method.label(fallThroughLabel);
- }
- caseNode.getBody().accept(this);
- }
-
- method.breakLabel(breakLabel, liveLocalsOnBreak);
-
- return false;
- }
-
- @Override
- public boolean enterThrowNode(final ThrowNode throwNode) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(throwNode);
-
- if (throwNode.isSyntheticRethrow()) {
- method.beforeJoinPoint(throwNode);
-
- //do not wrap whatever this is in an ecma exception, just rethrow it
- final IdentNode exceptionExpr = (IdentNode)throwNode.getExpression();
- final Symbol exceptionSymbol = exceptionExpr.getSymbol();
- method.load(exceptionSymbol, EXCEPTION_TYPE);
- method.checkcast(EXCEPTION_TYPE.getTypeClass());
- method.athrow();
- return false;
- }
-
- final Source source = getCurrentSource();
- final Expression expression = throwNode.getExpression();
- final int position = throwNode.position();
- final int line = throwNode.getLineNumber();
- final int column = source.getColumn(position);
-
- // NOTE: we first evaluate the expression, and only after it was evaluated do we create the new ECMAException
- // object and then somewhat cumbersomely move it beneath the evaluated expression on the stack. The reason for
- // this is that if expression is optimistic (or contains an optimistic subexpression), we'd potentially access
- // the not-yet-ialized object on the stack from the UnwarrantedOptimismException handler, and bytecode
- // verifier forbids that.
- loadExpressionAsObject(expression);
-
- method.load(source.getName());
- method.load(line);
- method.load(column);
- method.invoke(ECMAException.CREATE);
-
- method.beforeJoinPoint(throwNode);
- method.athrow();
-
- return false;
- }
-
- private Source getCurrentSource() {
- return lc.getCurrentFunction().getSource();
- }
-
- @Override
- public boolean enterTryNode(final TryNode tryNode) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(tryNode);
-
- final Block body = tryNode.getBody();
- final List catchBlocks = tryNode.getCatchBlocks();
- final Symbol vmException = tryNode.getException();
- final Label entry = new Label("try");
- final Label recovery = new Label("catch");
- final Label exit = new Label("end_try");
- final Label skip = new Label("skip");
-
- method.canThrow(recovery);
- // Effect any conversions that might be observed at the entry of the catch node before entering the try node.
- // This is because even the first instruction in the try block must be presumed to be able to transfer control
- // to the catch block. Note that this doesn't kill the original values; in this regard it works a lot like
- // conversions of assignments within the try block.
- method.beforeTry(tryNode, recovery);
- method.label(entry);
- catchLabels.push(recovery);
- try {
- body.accept(this);
- } finally {
- assert catchLabels.peek() == recovery;
- catchLabels.pop();
- }
-
- method.label(exit);
- final boolean bodyCanThrow = exit.isAfter(entry);
- if(!bodyCanThrow) {
- // The body can't throw an exception; don't even bother emitting the catch handlers, they're all dead code.
- return false;
- }
-
- method._try(entry, exit, recovery, Throwable.class);
-
- if (method.isReachable()) {
- method._goto(skip);
- }
-
- for (final Block inlinedFinally : tryNode.getInlinedFinallies()) {
- TryNode.getLabelledInlinedFinallyBlock(inlinedFinally).accept(this);
- // All inlined finallies end with a jump or a return
- assert !method.isReachable();
- }
-
-
- method._catch(recovery);
- method.store(vmException, EXCEPTION_TYPE);
-
- final int catchBlockCount = catchBlocks.size();
- final Label afterCatch = new Label("after_catch");
- for (int i = 0; i < catchBlockCount; i++) {
- assert method.isReachable();
- final Block catchBlock = catchBlocks.get(i);
-
- // Because of the peculiarities of the flow control, we need to use an explicit push/enterBlock/leaveBlock
- // here.
- lc.push(catchBlock);
- enterBlock(catchBlock);
-
- final CatchNode catchNode = (CatchNode)catchBlocks.get(i).getStatements().get(0);
- final IdentNode exception = catchNode.getExceptionIdentifier();
- final Expression exceptionCondition = catchNode.getExceptionCondition();
- final Block catchBody = catchNode.getBody();
-
- new Store(exception) {
- @Override
- protected void storeNonDiscard() {
- // This expression is neither part of a discard, nor needs to be left on the stack after it was
- // stored, so we override storeNonDiscard to be a no-op.
- }
-
- @Override
- protected void evaluate() {
- if (catchNode.isSyntheticRethrow()) {
- method.load(vmException, EXCEPTION_TYPE);
- return;
- }
- /*
- * If caught object is an instance of ECMAException, then
- * bind obj.thrown to the script catch var. Or else bind the
- * caught object itself to the script catch var.
- */
- final Label notEcmaException = new Label("no_ecma_exception");
- method.load(vmException, EXCEPTION_TYPE).dup()._instanceof(ECMAException.class).ifeq(notEcmaException);
- method.checkcast(ECMAException.class); //TODO is this necessary?
- method.getField(ECMAException.THROWN);
- method.label(notEcmaException);
- }
- }.store();
-
- final boolean isConditionalCatch = exceptionCondition != null;
- final Label nextCatch;
- if (isConditionalCatch) {
- loadExpressionAsBoolean(exceptionCondition);
- nextCatch = new Label("next_catch");
- nextCatch.markAsBreakTarget();
- method.ifeq(nextCatch);
- } else {
- nextCatch = null;
- }
-
- catchBody.accept(this);
- leaveBlock(catchBlock);
- lc.pop(catchBlock);
- if(nextCatch != null) {
- if(method.isReachable()) {
- method._goto(afterCatch);
- }
- method.breakLabel(nextCatch, lc.getUsedSlotCount());
- }
- }
-
- // afterCatch could be the same as skip, except that we need to establish that the vmException is dead.
- method.label(afterCatch);
- if(method.isReachable()) {
- method.markDeadLocalVariable(vmException);
- }
- method.label(skip);
-
- // Finally body is always inlined elsewhere so it doesn't need to be emitted
- assert tryNode.getFinallyBody() == null;
-
- return false;
- }
-
- @Override
- public boolean enterVarNode(final VarNode varNode) {
- if(!method.isReachable()) {
- return false;
- }
- final Expression init = varNode.getInit();
- final IdentNode identNode = varNode.getName();
- final Symbol identSymbol = identNode.getSymbol();
- assert identSymbol != null : "variable node " + varNode + " requires a name with a symbol";
- final boolean needsScope = identSymbol.isScope();
-
- if (init == null) {
- // Block-scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ).
- // However, don't do this for CONST which always has an initializer except in the special case of
- // for-in/of loops, in which it is initialized in the loop header and should be left untouched here.
- if (needsScope && varNode.isLet()) {
- method.loadCompilerConstant(SCOPE);
- method.loadUndefined(Type.OBJECT);
- final int flags = getScopeCallSiteFlags(identSymbol) | CALLSITE_DECLARE;
- assert isFastScope(identSymbol);
- storeFastScopeVar(identSymbol, flags);
- }
- return false;
- }
-
- enterStatement(varNode);
- assert method != null;
-
- if (needsScope) {
- method.loadCompilerConstant(SCOPE);
- loadExpressionUnbounded(init);
- // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ)
- final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0);
- if (isFastScope(identSymbol)) {
- storeFastScopeVar(identSymbol, flags);
- } else {
- method.dynamicSet(identNode.getName(), flags, false);
- }
- } else {
- final Type identType = identNode.getType();
- if(identType == Type.UNDEFINED) {
- // The initializer is either itself undefined (explicit assignment of undefined to undefined),
- // or the left hand side is a dead variable.
- assert init.getType() == Type.UNDEFINED || identNode.getSymbol().slotCount() == 0;
- loadAndDiscard(init);
- return false;
- }
- loadExpressionAsType(init, identType);
- storeIdentWithCatchConversion(identNode, identType);
- }
-
- return false;
- }
-
- private void storeIdentWithCatchConversion(final IdentNode identNode, final Type type) {
- // Assignments happening in try/catch blocks need to ensure that they also store a possibly wider typed value
- // that will be live at the exit from the try block
- final LocalVariableConversion conversion = identNode.getLocalVariableConversion();
- final Symbol symbol = identNode.getSymbol();
- if(conversion != null && conversion.isLive()) {
- assert symbol == conversion.getSymbol();
- assert symbol.isBytecodeLocal();
- // Only a single conversion from the target type to the join type is expected.
- assert conversion.getNext() == null;
- assert conversion.getFrom() == type;
- // We must propagate potential type change to the catch block
- final Label catchLabel = catchLabels.peek();
- assert catchLabel != METHOD_BOUNDARY; // ident conversion only exists in try blocks
- assert catchLabel.isReachable();
- final Type joinType = conversion.getTo();
- final Label.Stack catchStack = catchLabel.getStack();
- final int joinSlot = symbol.getSlot(joinType);
- // With nested try/catch blocks (incl. synthetic ones for finally), we can have a supposed conversion for
- // the exception symbol in the nested catch, but it isn't live in the outer catch block, so prevent doing
- // conversions for it. E.g. in "try { try { ... } catch(e) { e = 1; } } catch(e2) { ... }", we must not
- // introduce an I->O conversion on "e = 1" assignment as "e" is not live in "catch(e2)".
- if(catchStack.getUsedSlotsWithLiveTemporaries() > joinSlot) {
- method.dup();
- method.convert(joinType);
- method.store(symbol, joinType);
- catchLabel.getStack().onLocalStore(joinType, joinSlot, true);
- method.canThrow(catchLabel);
- // Store but keep the previous store live too.
- method.store(symbol, type, false);
- return;
- }
- }
-
- method.store(symbol, type, true);
- }
-
- @Override
- public boolean enterWhileNode(final WhileNode whileNode) {
- if(!method.isReachable()) {
- return false;
- }
- if(whileNode.isDoWhile()) {
- enterDoWhile(whileNode);
- } else {
- enterStatement(whileNode);
- enterForOrWhile(whileNode, null);
- }
- return false;
- }
-
- private void enterForOrWhile(final LoopNode loopNode, final JoinPredecessorExpression modify) {
- // NOTE: the usual pattern for compiling test-first loops is "GOTO test; body; test; IFNE body". We use the less
- // conventional "test; IFEQ break; body; GOTO test; break;". It has one extra unconditional GOTO in each repeat
- // of the loop, but it's not a problem for modern JIT compilers. We do this because our local variable type
- // tracking is unfortunately not really prepared for out-of-order execution, e.g. compiling the following
- // contrived but legal JavaScript code snippet would fail because the test changes the type of "i" from object
- // to double: var i = {valueOf: function() { return 1} }; while(--i >= 0) { ... }
- // Instead of adding more complexity to the local variable type tracking, we instead choose to emit this
- // different code shape.
- final int liveLocalsOnBreak = method.getUsedSlotsWithLiveTemporaries();
- final JoinPredecessorExpression test = loopNode.getTest();
- if(Expression.isAlwaysFalse(test)) {
- loadAndDiscard(test);
- return;
- }
-
- method.beforeJoinPoint(loopNode);
-
- final Label continueLabel = loopNode.getContinueLabel();
- final Label repeatLabel = modify != null ? new Label("for_repeat") : continueLabel;
- method.label(repeatLabel);
- final int liveLocalsOnContinue = method.getUsedSlotsWithLiveTemporaries();
-
- final Block body = loopNode.getBody();
- final Label breakLabel = loopNode.getBreakLabel();
- final boolean testHasLiveConversion = test != null && LocalVariableConversion.hasLiveConversion(test);
-
- if(Expression.isAlwaysTrue(test)) {
- if(test != null) {
- loadAndDiscard(test);
- if(testHasLiveConversion) {
- method.beforeJoinPoint(test);
- }
- }
- } else if (test != null) {
- if (testHasLiveConversion) {
- emitBranch(test.getExpression(), body.getEntryLabel(), true);
- method.beforeJoinPoint(test);
- method._goto(breakLabel);
- } else {
- emitBranch(test.getExpression(), breakLabel, false);
- }
- }
-
- body.accept(this);
- if(repeatLabel != continueLabel) {
- emitContinueLabel(continueLabel, liveLocalsOnContinue);
- }
-
- if (loopNode.hasPerIterationScope() && lc.getCurrentBlock().needsScope()) {
- // ES6 for loops with LET init need a new scope for each iteration. We just create a shallow copy here.
- method.loadCompilerConstant(SCOPE);
- method.invoke(virtualCallNoLookup(ScriptObject.class, "copy", ScriptObject.class));
- method.storeCompilerConstant(SCOPE);
- }
-
- if(method.isReachable()) {
- if(modify != null) {
- lineNumber(loopNode);
- loadAndDiscard(modify);
- method.beforeJoinPoint(modify);
- }
- method._goto(repeatLabel);
- }
-
- method.breakLabel(breakLabel, liveLocalsOnBreak);
- }
-
- private void emitContinueLabel(final Label continueLabel, final int liveLocals) {
- final boolean reachable = method.isReachable();
- method.breakLabel(continueLabel, liveLocals);
- // If we reach here only through a continue statement (e.g. body does not exit normally) then the
- // continueLabel can have extra non-temp symbols (e.g. exception from a try/catch contained in the body). We
- // must make sure those are thrown away.
- if(!reachable) {
- method.undefineLocalVariables(lc.getUsedSlotCount(), false);
- }
- }
-
- private void enterDoWhile(final WhileNode whileNode) {
- final int liveLocalsOnContinueOrBreak = method.getUsedSlotsWithLiveTemporaries();
- method.beforeJoinPoint(whileNode);
-
- final Block body = whileNode.getBody();
- body.accept(this);
-
- emitContinueLabel(whileNode.getContinueLabel(), liveLocalsOnContinueOrBreak);
- if(method.isReachable()) {
- lineNumber(whileNode);
- final JoinPredecessorExpression test = whileNode.getTest();
- final Label bodyEntryLabel = body.getEntryLabel();
- final boolean testHasLiveConversion = LocalVariableConversion.hasLiveConversion(test);
- if(Expression.isAlwaysFalse(test)) {
- loadAndDiscard(test);
- if(testHasLiveConversion) {
- method.beforeJoinPoint(test);
- }
- } else if(testHasLiveConversion) {
- // If we have conversions after the test in do-while, they need to be effected on both branches.
- final Label beforeExit = new Label("do_while_preexit");
- emitBranch(test.getExpression(), beforeExit, false);
- method.beforeJoinPoint(test);
- method._goto(bodyEntryLabel);
- method.label(beforeExit);
- method.beforeJoinPoint(test);
- } else {
- emitBranch(test.getExpression(), bodyEntryLabel, true);
- }
- }
- method.breakLabel(whileNode.getBreakLabel(), liveLocalsOnContinueOrBreak);
- }
-
-
- @Override
- public boolean enterWithNode(final WithNode withNode) {
- if(!method.isReachable()) {
- return false;
- }
- enterStatement(withNode);
- final Expression expression = withNode.getExpression();
- final Block body = withNode.getBody();
-
- // It is possible to have a "pathological" case where the with block does not reference *any* identifiers. It's
- // pointless, but legal. In that case, if nothing else in the method forced the assignment of a slot to the
- // scope object, its' possible that it won't have a slot assigned. In this case we'll only evaluate expression
- // for its side effect and visit the body, and not bother opening and closing a WithObject.
- final boolean hasScope = method.hasScope();
-
- if (hasScope) {
- method.loadCompilerConstant(SCOPE);
- }
-
- loadExpressionAsObject(expression);
-
- final Label tryLabel;
- if (hasScope) {
- // Construct a WithObject if we have a scope
- method.invoke(ScriptRuntime.OPEN_WITH);
- method.storeCompilerConstant(SCOPE);
- tryLabel = new Label("with_try");
- method.label(tryLabel);
- } else {
- // We just loaded the expression for its side effect and to check
- // for null or undefined value.
- globalCheckObjectCoercible();
- tryLabel = null;
- }
-
- // Always process body
- body.accept(this);
-
- if (hasScope) {
- // Ensure we always close the WithObject
- final Label endLabel = new Label("with_end");
- final Label catchLabel = new Label("with_catch");
- final Label exitLabel = new Label("with_exit");
-
- method.label(endLabel);
- // Somewhat conservatively presume that if the body is not empty, it can throw an exception. In any case,
- // we must prevent trying to emit a try-catch for empty range, as it causes a verification error.
- final boolean bodyCanThrow = endLabel.isAfter(tryLabel);
- if(bodyCanThrow) {
- method._try(tryLabel, endLabel, catchLabel);
- }
-
- final boolean reachable = method.isReachable();
- if(reachable) {
- popScope();
- if(bodyCanThrow) {
- method._goto(exitLabel);
- }
- }
-
- if(bodyCanThrow) {
- method._catch(catchLabel);
- popScopeException();
- method.athrow();
- if(reachable) {
- method.label(exitLabel);
- }
- }
- }
- return false;
- }
-
- private void loadADD(final UnaryNode unaryNode, final TypeBounds resultBounds) {
- loadExpression(unaryNode.getExpression(), resultBounds.booleanToInt().notWiderThan(Type.NUMBER));
- if(method.peekType() == Type.BOOLEAN) {
- // It's a no-op in bytecode, but we must make sure it is treated as an int for purposes of type signatures
- method.convert(Type.INT);
- }
- }
-
- private void loadBIT_NOT(final UnaryNode unaryNode) {
- loadExpression(unaryNode.getExpression(), TypeBounds.INT).load(-1).xor();
- }
-
- private void loadDECINC(final UnaryNode unaryNode) {
- final Expression operand = unaryNode.getExpression();
- final Type type = unaryNode.getType();
- final TypeBounds typeBounds = new TypeBounds(type, Type.NUMBER);
- final TokenType tokenType = unaryNode.tokenType();
- final boolean isPostfix = tokenType == TokenType.DECPOSTFIX || tokenType == TokenType.INCPOSTFIX;
- final boolean isIncrement = tokenType == TokenType.INCPREFIX || tokenType == TokenType.INCPOSTFIX;
-
- assert !type.isObject();
-
- new SelfModifyingStore(unaryNode, operand) {
-
- private void loadRhs() {
- loadExpression(operand, typeBounds, true);
- }
-
- @Override
- protected void evaluate() {
- if(isPostfix) {
- loadRhs();
- } else {
- new OptimisticOperation(unaryNode, typeBounds) {
- @Override
- void loadStack() {
- loadRhs();
- loadMinusOne();
- }
- @Override
- void consumeStack() {
- doDecInc(getProgramPoint());
- }
- }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(operand));
- }
- }
-
- @Override
- protected void storeNonDiscard() {
- super.storeNonDiscard();
- if (isPostfix) {
- new OptimisticOperation(unaryNode, typeBounds) {
- @Override
- void loadStack() {
- loadMinusOne();
- }
- @Override
- void consumeStack() {
- doDecInc(getProgramPoint());
- }
- }.emit(1); // 1 for non-incremented result on the top of the stack pushed in evaluate()
- }
- }
-
- private void loadMinusOne() {
- if (type.isInteger()) {
- method.load(isIncrement ? 1 : -1);
- } else {
- method.load(isIncrement ? 1.0 : -1.0);
- }
- }
-
- private void doDecInc(final int programPoint) {
- method.add(programPoint);
- }
- }.store();
- }
-
- private static int getOptimisticIgnoreCountForSelfModifyingExpression(final Expression target) {
- return target instanceof AccessNode ? 1 : target instanceof IndexNode ? 2 : 0;
- }
-
- private void loadAndDiscard(final Expression expr) {
- // TODO: move checks for discarding to actual expression load code (e.g. as we do with void). That way we might
- // be able to eliminate even more checks.
- if(expr instanceof PrimitiveLiteralNode | isLocalVariable(expr)) {
- assert !lc.isCurrentDiscard(expr);
- // Don't bother evaluating expressions without side effects. Typical usage is "void 0" for reliably generating
- // undefined.
- return;
- }
-
- lc.pushDiscard(expr);
- loadExpression(expr, TypeBounds.UNBOUNDED);
- if (lc.popDiscardIfCurrent(expr)) {
- assert !expr.isAssignment();
- // NOTE: if we had a way to load with type void, we could avoid popping
- method.pop();
- }
- }
-
- /**
- * Loads the expression with the specified type bounds, but if the parent expression is the current discard,
- * then instead loads and discards the expression.
- * @param parent the parent expression that's tested for being the current discard
- * @param expr the expression that's either normally loaded or discard-loaded
- * @param resultBounds result bounds for when loading the expression normally
- */
- private void loadMaybeDiscard(final Expression parent, final Expression expr, final TypeBounds resultBounds) {
- loadMaybeDiscard(lc.popDiscardIfCurrent(parent), expr, resultBounds);
- }
-
- /**
- * Loads the expression with the specified type bounds, or loads and discards the expression, depending on the
- * value of the discard flag. Useful as a helper for expressions with control flow where you often can't combine
- * testing for being the current discard and loading the subexpressions.
- * @param discard if true, the expression is loaded and discarded
- * @param expr the expression that's either normally loaded or discard-loaded
- * @param resultBounds result bounds for when loading the expression normally
- */
- private void loadMaybeDiscard(final boolean discard, final Expression expr, final TypeBounds resultBounds) {
- if (discard) {
- loadAndDiscard(expr);
- } else {
- loadExpression(expr, resultBounds);
- }
- }
-
- private void loadNEW(final UnaryNode unaryNode) {
- final CallNode callNode = (CallNode)unaryNode.getExpression();
- final List args = callNode.getArgs();
-
- final Expression func = callNode.getFunction();
- // Load function reference.
- loadExpressionAsObject(func); // must detect type error
-
- method.dynamicNew(1 + loadArgs(args), getCallSiteFlags(), func.toString(false));
- }
-
- private void loadNOT(final UnaryNode unaryNode) {
- final Expression expr = unaryNode.getExpression();
- if(expr instanceof UnaryNode && expr.isTokenType(TokenType.NOT)) {
- // !!x is idiomatic boolean cast in JavaScript
- loadExpressionAsBoolean(((UnaryNode)expr).getExpression());
- } else {
- final Label trueLabel = new Label("true");
- final Label afterLabel = new Label("after");
-
- emitBranch(expr, trueLabel, true);
- method.load(true);
- method._goto(afterLabel);
- method.label(trueLabel);
- method.load(false);
- method.label(afterLabel);
- }
- }
-
- private void loadSUB(final UnaryNode unaryNode, final TypeBounds resultBounds) {
- final Type type = unaryNode.getType();
- assert type.isNumeric();
- final TypeBounds numericBounds = resultBounds.booleanToInt();
- new OptimisticOperation(unaryNode, numericBounds) {
- @Override
- void loadStack() {
- final Expression expr = unaryNode.getExpression();
- loadExpression(expr, numericBounds.notWiderThan(Type.NUMBER));
- }
- @Override
- void consumeStack() {
- // Must do an explicit conversion to the operation's type when it's double so that we correctly handle
- // negation of an int 0 to a double -0. With this, we get the correct negation of a local variable after
- // it deoptimized, e.g. "iload_2; i2d; dneg". Without this, we get "iload_2; ineg; i2d".
- if(type.isNumber()) {
- method.convert(type);
- }
- method.neg(getProgramPoint());
- }
- }.emit();
- }
-
- public void loadVOID(final UnaryNode unaryNode, final TypeBounds resultBounds) {
- loadAndDiscard(unaryNode.getExpression());
- if (!lc.popDiscardIfCurrent(unaryNode)) {
- method.loadUndefined(resultBounds.widest);
- }
- }
-
- public void loadDELETE(final UnaryNode unaryNode) {
- final Expression expression = unaryNode.getExpression();
- if (expression instanceof IdentNode) {
- final IdentNode ident = (IdentNode)expression;
- final Symbol symbol = ident.getSymbol();
- final String name = ident.getName();
-
- if (symbol.isThis()) {
- // Can't delete "this", ignore and return true
- if (!lc.popDiscardIfCurrent(unaryNode)) {
- method.load(true);
- }
- } else if (lc.getCurrentFunction().isStrict()) {
- // All other scope identifier delete attempts fail for strict mode
- method.load(name);
- method.invoke(ScriptRuntime.STRICT_FAIL_DELETE);
- } else if (!symbol.isScope() && (symbol.isParam() || (symbol.isVar() && !symbol.isProgramLevel()))) {
- // If symbol is a function parameter, or a declared non-global variable, delete is a no-op and returns false.
- if (!lc.popDiscardIfCurrent(unaryNode)) {
- method.load(false);
- }
- } else {
- method.loadCompilerConstant(SCOPE);
- method.load(name);
- if ((symbol.isGlobal() && !symbol.isFunctionDeclaration()) || symbol.isProgramLevel()) {
- method.invoke(ScriptRuntime.SLOW_DELETE);
- } else {
- method.load(false); // never strict here; that was handled with STRICT_FAIL_DELETE above.
- method.invoke(ScriptObject.DELETE);
- }
- }
- } else if (expression instanceof BaseNode) {
- loadExpressionAsObject(((BaseNode)expression).getBase());
- if (expression instanceof AccessNode) {
- final AccessNode accessNode = (AccessNode) expression;
- method.dynamicRemove(accessNode.getProperty(), getCallSiteFlags(), accessNode.isIndex());
- } else if (expression instanceof IndexNode) {
- loadExpressionAsObject(((IndexNode) expression).getIndex());
- method.dynamicRemoveIndex(getCallSiteFlags());
- } else {
- throw new AssertionError(expression.getClass().getName());
- }
- } else {
- throw new AssertionError(expression.getClass().getName());
- }
- }
-
- public void loadADD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
- new OptimisticOperation(binaryNode, resultBounds) {
- @Override
- void loadStack() {
- final TypeBounds operandBounds;
- final boolean isOptimistic = isValid(getProgramPoint());
- boolean forceConversionSeparation = false;
- if(isOptimistic) {
- operandBounds = new TypeBounds(binaryNode.getType(), Type.OBJECT);
- } else {
- // Non-optimistic, non-FP +. Allow it to overflow.
- final Type widestOperationType = binaryNode.getWidestOperationType();
- operandBounds = new TypeBounds(Type.narrowest(binaryNode.getWidestOperandType(), resultBounds.widest), widestOperationType);
- forceConversionSeparation = widestOperationType.narrowerThan(resultBounds.widest);
- }
- loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), operandBounds, false, forceConversionSeparation);
- }
-
- @Override
- void consumeStack() {
- method.add(getProgramPoint());
- }
- }.emit();
- }
-
- private void loadAND_OR(final BinaryNode binaryNode, final TypeBounds resultBounds, final boolean isAnd) {
- final Type narrowestOperandType = Type.widestReturnType(binaryNode.lhs().getType(), binaryNode.rhs().getType());
-
- final boolean isCurrentDiscard = lc.popDiscardIfCurrent(binaryNode);
-
- final Label skip = new Label("skip");
- if(narrowestOperandType == Type.BOOLEAN) {
- // optimize all-boolean logical expressions
- final Label onTrue = new Label("andor_true");
- emitBranch(binaryNode, onTrue, true);
- if (isCurrentDiscard) {
- method.label(onTrue);
- } else {
- method.load(false);
- method._goto(skip);
- method.label(onTrue);
- method.load(true);
- method.label(skip);
- }
- return;
- }
-
- final TypeBounds outBounds = resultBounds.notNarrowerThan(narrowestOperandType);
- final JoinPredecessorExpression lhs = (JoinPredecessorExpression)binaryNode.lhs();
- final boolean lhsConvert = LocalVariableConversion.hasLiveConversion(lhs);
- final Label evalRhs = lhsConvert ? new Label("eval_rhs") : null;
-
- loadExpression(lhs, outBounds);
- if (!isCurrentDiscard) {
- method.dup();
- }
- method.convert(Type.BOOLEAN);
- if (isAnd) {
- if(lhsConvert) {
- method.ifne(evalRhs);
- } else {
- method.ifeq(skip);
- }
- } else if(lhsConvert) {
- method.ifeq(evalRhs);
- } else {
- method.ifne(skip);
- }
-
- if(lhsConvert) {
- method.beforeJoinPoint(lhs);
- method._goto(skip);
- method.label(evalRhs);
- }
-
- if (!isCurrentDiscard) {
- method.pop();
- }
- final JoinPredecessorExpression rhs = (JoinPredecessorExpression)binaryNode.rhs();
- loadMaybeDiscard(isCurrentDiscard, rhs, outBounds);
- method.beforeJoinPoint(rhs);
- method.label(skip);
- }
-
- private static boolean isLocalVariable(final Expression lhs) {
- return lhs instanceof IdentNode && isLocalVariable((IdentNode)lhs);
- }
-
- private static boolean isLocalVariable(final IdentNode lhs) {
- return lhs.getSymbol().isBytecodeLocal();
- }
-
- // NOTE: does not use resultBounds as the assignment is driven by the type of the RHS
- private void loadASSIGN(final BinaryNode binaryNode) {
- final Expression lhs = binaryNode.lhs();
- final Expression rhs = binaryNode.rhs();
-
- final Type rhsType = rhs.getType();
- // Detect dead assignments
- if(lhs instanceof IdentNode) {
- final Symbol symbol = ((IdentNode)lhs).getSymbol();
- if(!symbol.isScope() && !symbol.hasSlotFor(rhsType) && lc.popDiscardIfCurrent(binaryNode)) {
- loadAndDiscard(rhs);
- method.markDeadLocalVariable(symbol);
- return;
- }
- }
-
- new Store(binaryNode, lhs) {
- @Override
- protected void evaluate() {
- // NOTE: we're loading with "at least as wide as" so optimistic operations on the right hand side
- // remain optimistic, and then explicitly convert to the required type if needed.
- loadExpressionAsType(rhs, rhsType);
- }
- }.store();
- }
-
- /**
- * Binary self-assignment that can be optimistic: +=, -=, *=, and /=.
- */
- private abstract class BinaryOptimisticSelfAssignment extends SelfModifyingStore {
-
- /**
- * Constructor
- *
- * @param node the assign op node
- */
- BinaryOptimisticSelfAssignment(final BinaryNode node) {
- super(node, node.lhs());
- }
-
- protected abstract void op(OptimisticOperation oo);
-
- @Override
- protected void evaluate() {
- final Expression lhs = assignNode.lhs();
- final Expression rhs = assignNode.rhs();
- final Type widestOperationType = assignNode.getWidestOperationType();
- final TypeBounds bounds = new TypeBounds(assignNode.getType(), widestOperationType);
- new OptimisticOperation(assignNode, bounds) {
- @Override
- void loadStack() {
- final boolean forceConversionSeparation;
- if (isValid(getProgramPoint()) || widestOperationType == Type.NUMBER) {
- forceConversionSeparation = false;
- } else {
- final Type operandType = Type.widest(booleanToInt(objectToNumber(lhs.getType())), booleanToInt(objectToNumber(rhs.getType())));
- forceConversionSeparation = operandType.narrowerThan(widestOperationType);
- }
- loadBinaryOperands(lhs, rhs, bounds, true, forceConversionSeparation);
- }
- @Override
- void consumeStack() {
- op(this);
- }
- }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(lhs));
- method.convert(assignNode.getType());
- }
- }
-
- /**
- * Non-optimistic binary self-assignment operation. Basically, everything except +=, -=, *=, and /=.
- */
- private abstract class BinarySelfAssignment extends SelfModifyingStore {
- BinarySelfAssignment(final BinaryNode node) {
- super(node, node.lhs());
- }
-
- protected abstract void op();
-
- @Override
- protected void evaluate() {
- loadBinaryOperands(assignNode.lhs(), assignNode.rhs(), TypeBounds.UNBOUNDED.notWiderThan(assignNode.getWidestOperandType()), true, false);
- op();
- }
- }
-
- private void loadASSIGN_ADD(final BinaryNode binaryNode) {
- new BinaryOptimisticSelfAssignment(binaryNode) {
- @Override
- protected void op(final OptimisticOperation oo) {
- assert !(binaryNode.getType().isObject() && oo.isOptimistic);
- method.add(oo.getProgramPoint());
- }
- }.store();
- }
-
- private void loadASSIGN_BIT_AND(final BinaryNode binaryNode) {
- new BinarySelfAssignment(binaryNode) {
- @Override
- protected void op() {
- method.and();
- }
- }.store();
- }
-
- private void loadASSIGN_BIT_OR(final BinaryNode binaryNode) {
- new BinarySelfAssignment(binaryNode) {
- @Override
- protected void op() {
- method.or();
- }
- }.store();
- }
-
- private void loadASSIGN_BIT_XOR(final BinaryNode binaryNode) {
- new BinarySelfAssignment(binaryNode) {
- @Override
- protected void op() {
- method.xor();
- }
- }.store();
- }
-
- private void loadASSIGN_DIV(final BinaryNode binaryNode) {
- new BinaryOptimisticSelfAssignment(binaryNode) {
- @Override
- protected void op(final OptimisticOperation oo) {
- method.div(oo.getProgramPoint());
- }
- }.store();
- }
-
- private void loadASSIGN_MOD(final BinaryNode binaryNode) {
- new BinaryOptimisticSelfAssignment(binaryNode) {
- @Override
- protected void op(final OptimisticOperation oo) {
- method.rem(oo.getProgramPoint());
- }
- }.store();
- }
-
- private void loadASSIGN_MUL(final BinaryNode binaryNode) {
- new BinaryOptimisticSelfAssignment(binaryNode) {
- @Override
- protected void op(final OptimisticOperation oo) {
- method.mul(oo.getProgramPoint());
- }
- }.store();
- }
-
- private void loadASSIGN_SAR(final BinaryNode binaryNode) {
- new BinarySelfAssignment(binaryNode) {
- @Override
- protected void op() {
- method.sar();
- }
- }.store();
- }
-
- private void loadASSIGN_SHL(final BinaryNode binaryNode) {
- new BinarySelfAssignment(binaryNode) {
- @Override
- protected void op() {
- method.shl();
- }
- }.store();
- }
-
- private void loadASSIGN_SHR(final BinaryNode binaryNode) {
- new SelfModifyingStore(binaryNode, binaryNode.lhs()) {
- @Override
- protected void evaluate() {
- new OptimisticOperation(assignNode, new TypeBounds(Type.INT, Type.NUMBER)) {
- @Override
- void loadStack() {
- assert assignNode.getWidestOperandType() == Type.INT;
- if (isRhsZero(binaryNode)) {
- loadExpression(binaryNode.lhs(), TypeBounds.INT, true);
- } else {
- loadBinaryOperands(binaryNode.lhs(), binaryNode.rhs(), TypeBounds.INT, true, false);
- method.shr();
- }
- }
-
- @Override
- void consumeStack() {
- if (isOptimistic(binaryNode)) {
- toUint32Optimistic(binaryNode.getProgramPoint());
- } else {
- toUint32Double();
- }
- }
- }.emit(getOptimisticIgnoreCountForSelfModifyingExpression(binaryNode.lhs()));
- method.convert(assignNode.getType());
- }
- }.store();
- }
-
- private void doSHR(final BinaryNode binaryNode) {
- new OptimisticOperation(binaryNode, new TypeBounds(Type.INT, Type.NUMBER)) {
- @Override
- void loadStack() {
- if (isRhsZero(binaryNode)) {
- loadExpressionAsType(binaryNode.lhs(), Type.INT);
- } else {
- loadBinaryOperands(binaryNode);
- method.shr();
- }
- }
-
- @Override
- void consumeStack() {
- if (isOptimistic(binaryNode)) {
- toUint32Optimistic(binaryNode.getProgramPoint());
- } else {
- toUint32Double();
- }
- }
- }.emit();
-
- }
-
- private void toUint32Optimistic(final int programPoint) {
- method.load(programPoint);
- JSType.TO_UINT32_OPTIMISTIC.invoke(method);
- }
-
- private void toUint32Double() {
- JSType.TO_UINT32_DOUBLE.invoke(method);
- }
-
- private void loadASSIGN_SUB(final BinaryNode binaryNode) {
- new BinaryOptimisticSelfAssignment(binaryNode) {
- @Override
- protected void op(final OptimisticOperation oo) {
- method.sub(oo.getProgramPoint());
- }
- }.store();
- }
-
- /**
- * Helper class for binary arithmetic ops
- */
- private abstract class BinaryArith {
- protected abstract void op(int programPoint);
-
- protected void evaluate(final BinaryNode node, final TypeBounds resultBounds) {
- final TypeBounds numericBounds = resultBounds.booleanToInt().objectToNumber();
- new OptimisticOperation(node, numericBounds) {
- @Override
- void loadStack() {
- final TypeBounds operandBounds;
- boolean forceConversionSeparation = false;
- if(numericBounds.narrowest == Type.NUMBER) {
- // Result should be double always. Propagate it into the operands so we don't have lots of I2D
- // and L2D after operand evaluation.
- assert numericBounds.widest == Type.NUMBER;
- operandBounds = numericBounds;
- } else {
- final boolean isOptimistic = isValid(getProgramPoint());
- if(isOptimistic || node.isTokenType(TokenType.DIV) || node.isTokenType(TokenType.MOD)) {
- operandBounds = new TypeBounds(node.getType(), Type.NUMBER);
- } else {
- // Non-optimistic, non-FP subtraction or multiplication. Allow them to overflow.
- operandBounds = new TypeBounds(Type.narrowest(node.getWidestOperandType(),
- numericBounds.widest), Type.NUMBER);
- forceConversionSeparation = true;
- }
- }
- loadBinaryOperands(node.lhs(), node.rhs(), operandBounds, false, forceConversionSeparation);
- }
-
- @Override
- void consumeStack() {
- op(getProgramPoint());
- }
- }.emit();
- }
- }
-
- private void loadBIT_AND(final BinaryNode binaryNode) {
- loadBinaryOperands(binaryNode);
- method.and();
- }
-
- private void loadBIT_OR(final BinaryNode binaryNode) {
- // Optimize x|0 to (int)x
- if (isRhsZero(binaryNode)) {
- loadExpressionAsType(binaryNode.lhs(), Type.INT);
- } else {
- loadBinaryOperands(binaryNode);
- method.or();
- }
- }
-
- private static boolean isRhsZero(final BinaryNode binaryNode) {
- final Expression rhs = binaryNode.rhs();
- return rhs instanceof LiteralNode && INT_ZERO.equals(((LiteralNode)rhs).getValue());
- }
-
- private void loadBIT_XOR(final BinaryNode binaryNode) {
- loadBinaryOperands(binaryNode);
- method.xor();
- }
-
- private void loadCOMMARIGHT(final BinaryNode binaryNode, final TypeBounds resultBounds) {
- loadAndDiscard(binaryNode.lhs());
- loadMaybeDiscard(binaryNode, binaryNode.rhs(), resultBounds);
- }
-
- private void loadDIV(final BinaryNode binaryNode, final TypeBounds resultBounds) {
- new BinaryArith() {
- @Override
- protected void op(final int programPoint) {
- method.div(programPoint);
- }
- }.evaluate(binaryNode, resultBounds);
- }
-
- private void loadCmp(final BinaryNode binaryNode, final Condition cond) {
- loadComparisonOperands(binaryNode);
-
- final Label trueLabel = new Label("trueLabel");
- final Label afterLabel = new Label("skip");
-
- method.conditionalJump(cond, trueLabel);
-
- method.load(Boolean.FALSE);
- method._goto(afterLabel);
- method.label(trueLabel);
- method.load(Boolean.TRUE);
- method.label(afterLabel);
- }
-
- private void loadMOD(final BinaryNode binaryNode, final TypeBounds resultBounds) {
- new BinaryArith() {
- @Override
- protected void op(final int programPoint) {
- method.rem(programPoint);
- }
- }.evaluate(binaryNode, resultBounds);
- }
-
- private void loadMUL(final BinaryNode binaryNode, final TypeBounds resultBounds) {
- new BinaryArith() {
- @Override
- protected void op(final int programPoint) {
- method.mul(programPoint);
- }
- }.evaluate(binaryNode, resultBounds);
- }
-
- private void loadSAR(final BinaryNode binaryNode) {
- loadBinaryOperands(binaryNode);
- method.sar();
- }
-
- private void loadSHL(final BinaryNode binaryNode) {
- loadBinaryOperands(binaryNode);
- method.shl();
- }
-
- private void loadSHR(final BinaryNode binaryNode) {
- doSHR(binaryNode);
- }
-
- private void loadSUB(final BinaryNode binaryNode, final TypeBounds resultBounds) {
- new BinaryArith() {
- @Override
- protected void op(final int programPoint) {
- method.sub(programPoint);
- }
- }.evaluate(binaryNode, resultBounds);
- }
-
- @Override
- public boolean enterLabelNode(final LabelNode labelNode) {
- labeledBlockBreakLiveLocals.push(lc.getUsedSlotCount());
- return true;
- }
-
- @Override
- protected boolean enterDefault(final Node node) {
- throw new AssertionError("Code generator entered node of type " + node.getClass().getName());
- }
-
- private void loadTernaryNode(final TernaryNode ternaryNode, final TypeBounds resultBounds) {
- final Expression test = ternaryNode.getTest();
- final JoinPredecessorExpression trueExpr = ternaryNode.getTrueExpression();
- final JoinPredecessorExpression falseExpr = ternaryNode.getFalseExpression();
-
- final Label falseLabel = new Label("ternary_false");
- final Label exitLabel = new Label("ternary_exit");
-
- final Type outNarrowest = Type.narrowest(resultBounds.widest, Type.generic(Type.widestReturnType(trueExpr.getType(), falseExpr.getType())));
- final TypeBounds outBounds = resultBounds.notNarrowerThan(outNarrowest);
-
- emitBranch(test, falseLabel, false);
-
- final boolean isCurrentDiscard = lc.popDiscardIfCurrent(ternaryNode);
- loadMaybeDiscard(isCurrentDiscard, trueExpr.getExpression(), outBounds);
- assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
- method.beforeJoinPoint(trueExpr);
- method._goto(exitLabel);
- method.label(falseLabel);
- loadMaybeDiscard(isCurrentDiscard, falseExpr.getExpression(), outBounds);
- assert isCurrentDiscard || Type.generic(method.peekType()) == outBounds.narrowest;
- method.beforeJoinPoint(falseExpr);
- method.label(exitLabel);
- }
-
- /**
- * Generate all shared scope calls generated during codegen.
- */
- void generateScopeCalls() {
- for (final SharedScopeCall scopeAccess : lc.getScopeCalls()) {
- scopeAccess.generateScopeCall();
- }
- }
-
- /**
- * Debug code used to print symbols
- *
- * @param block the block we are in
- * @param function the function we are in
- * @param ident identifier for block or function where applicable
- */
- private void printSymbols(final Block block, final FunctionNode function, final String ident) {
- if (compiler.getScriptEnvironment()._print_symbols || function.getDebugFlag(FunctionNode.DEBUG_PRINT_SYMBOLS)) {
- final PrintWriter out = compiler.getScriptEnvironment().getErr();
- out.println("[BLOCK in '" + ident + "']");
- if (!block.printSymbols(out)) {
- out.println("");
- }
- out.println();
- }
- }
-
-
- /**
- * The difference between a store and a self modifying store is that
- * the latter may load part of the target on the stack, e.g. the base
- * of an AccessNode or the base and index of an IndexNode. These are used
- * both as target and as an extra source. Previously it was problematic
- * for self modifying stores if the target/lhs didn't belong to one
- * of three trivial categories: IdentNode, AcessNodes, IndexNodes. In that
- * case it was evaluated and tagged as "resolved", which meant at the second
- * time the lhs of this store was read (e.g. in a = a (second) + b for a += b,
- * it would be evaluated to a nop in the scope and cause stack underflow
- *
- * see NASHORN-703
- *
- * @param
- */
- private abstract class SelfModifyingStore extends Store {
- protected SelfModifyingStore(final T assignNode, final Expression target) {
- super(assignNode, target);
- }
-
- @Override
- protected boolean isSelfModifying() {
- return true;
- }
- }
-
- /**
- * Helper class to generate stores
- */
- private abstract class Store {
-
- /** An assignment node, e.g. x += y */
- protected final T assignNode;
-
- /** The target node to store to, e.g. x */
- private final Expression target;
-
- /** How deep on the stack do the arguments go if this generates an indy call */
- private int depth;
-
- /** If we have too many arguments, we need temporary storage, this is stored in 'quick' */
- private IdentNode quick;
-
- /**
- * Constructor
- *
- * @param assignNode the node representing the whole assignment
- * @param target the target node of the assignment (destination)
- */
- protected Store(final T assignNode, final Expression target) {
- this.assignNode = assignNode;
- this.target = target;
- }
-
- /**
- * Constructor
- *
- * @param assignNode the node representing the whole assignment
- */
- protected Store(final T assignNode) {
- this(assignNode, assignNode);
- }
-
- /**
- * Is this a self modifying store operation, e.g. *= or ++
- * @return true if self modifying store
- */
- protected boolean isSelfModifying() {
- return false;
- }
-
- private void prologue() {
- /*
- * This loads the parts of the target, e.g base and index. they are kept
- * on the stack throughout the store and used at the end to execute it
- */
-
- target.accept(new SimpleNodeVisitor() {
- @Override
- public boolean enterIdentNode(final IdentNode node) {
- if (node.getSymbol().isScope()) {
- method.loadCompilerConstant(SCOPE);
- depth += Type.SCOPE.getSlots();
- assert depth == 1;
- }
- return false;
- }
-
- private void enterBaseNode() {
- assert target instanceof BaseNode : "error - base node " + target + " must be instanceof BaseNode";
- final BaseNode baseNode = (BaseNode)target;
- final Expression base = baseNode.getBase();
-
- loadExpressionAsObject(base);
- depth += Type.OBJECT.getSlots();
- assert depth == 1;
-
- if (isSelfModifying()) {
- method.dup();
- }
- }
-
- @Override
- public boolean enterAccessNode(final AccessNode node) {
- enterBaseNode();
- return false;
- }
-
- @Override
- public boolean enterIndexNode(final IndexNode node) {
- enterBaseNode();
-
- final Expression index = node.getIndex();
- if (!index.getType().isNumeric()) {
- // could be boolean here as well
- loadExpressionAsObject(index);
- } else {
- loadExpressionUnbounded(index);
- }
- depth += index.getType().getSlots();
-
- if (isSelfModifying()) {
- //convert "base base index" to "base index base index"
- method.dup(1);
- }
-
- return false;
- }
-
- });
- }
-
- /**
- * Generates an extra local variable, always using the same slot, one that is available after the end of the
- * frame.
- *
- * @param type the type of the variable
- *
- * @return the quick variable
- */
- private IdentNode quickLocalVariable(final Type type) {
- final String name = lc.getCurrentFunction().uniqueName(QUICK_PREFIX.symbolName());
- final Symbol symbol = new Symbol(name, IS_INTERNAL | HAS_SLOT);
- symbol.setHasSlotFor(type);
- symbol.setFirstSlot(lc.quickSlot(type));
-
- final IdentNode quickIdent = IdentNode.createInternalIdentifier(symbol).setType(type);
-
- return quickIdent;
- }
-
- // store the result that "lives on" after the op, e.g. "i" in i++ postfix.
- protected void storeNonDiscard() {
- if (lc.popDiscardIfCurrent(assignNode)) {
- assert assignNode.isAssignment();
- return;
- }
-
- if (method.dup(depth) == null) {
- method.dup();
- final Type quickType = method.peekType();
- this.quick = quickLocalVariable(quickType);
- final Symbol quickSymbol = quick.getSymbol();
- method.storeTemp(quickType, quickSymbol.getFirstSlot());
- }
- }
-
- private void epilogue() {
- /**
- * Take the original target args from the stack and use them
- * together with the value to be stored to emit the store code
- *
- * The case that targetSymbol is in scope (!hasSlot) and we actually
- * need to do a conversion on non-equivalent types exists, but is
- * very rare. See for example test/script/basic/access-specializer.js
- */
- target.accept(new SimpleNodeVisitor() {
- @Override
- protected boolean enterDefault(final Node node) {
- throw new AssertionError("Unexpected node " + node + " in store epilogue");
- }
-
- @Override
- public boolean enterIdentNode(final IdentNode node) {
- final Symbol symbol = node.getSymbol();
- assert symbol != null;
- if (symbol.isScope()) {
- final int flags = getScopeCallSiteFlags(symbol) | (node.isDeclaredHere() ? CALLSITE_DECLARE : 0);
- if (isFastScope(symbol)) {
- storeFastScopeVar(symbol, flags);
- } else {
- method.dynamicSet(node.getName(), flags, false);
- }
- } else {
- final Type storeType = assignNode.getType();
- assert storeType != Type.LONG;
- if (symbol.hasSlotFor(storeType)) {
- // Only emit a convert for a store known to be live; converts for dead stores can
- // give us an unnecessary ClassCastException.
- method.convert(storeType);
- }
- storeIdentWithCatchConversion(node, storeType);
- }
- return false;
-
- }
-
- @Override
- public boolean enterAccessNode(final AccessNode node) {
- method.dynamicSet(node.getProperty(), getCallSiteFlags(), node.isIndex());
- return false;
- }
-
- @Override
- public boolean enterIndexNode(final IndexNode node) {
- method.dynamicSetIndex(getCallSiteFlags());
- return false;
- }
- });
-
-
- // whatever is on the stack now is the final answer
- }
-
- protected abstract void evaluate();
-
- void store() {
- if (target instanceof IdentNode) {
- checkTemporalDeadZone((IdentNode)target);
- }
- prologue();
- evaluate(); // leaves an operation of whatever the operationType was on the stack
- storeNonDiscard();
- epilogue();
- if (quick != null) {
- method.load(quick);
- }
- }
- }
-
- private void newFunctionObject(final FunctionNode functionNode, final boolean addInitializer) {
- assert lc.peek() == functionNode;
-
- final RecompilableScriptFunctionData data = compiler.getScriptFunctionData(functionNode.getId());
-
- if (functionNode.isProgram() && !compiler.isOnDemandCompilation()) {
- final MethodEmitter createFunction = functionNode.getCompileUnit().getClassEmitter().method(
- EnumSet.of(Flag.PUBLIC, Flag.STATIC), CREATE_PROGRAM_FUNCTION.symbolName(),
- ScriptFunction.class, ScriptObject.class);
- createFunction.begin();
- loadConstantsAndIndex(data, createFunction);
- createFunction.load(SCOPE_TYPE, 0);
- createFunction.invoke(CREATE_FUNCTION_OBJECT);
- createFunction._return();
- createFunction.end();
- }
-
- if (addInitializer && !compiler.isOnDemandCompilation()) {
- functionNode.getCompileUnit().addFunctionInitializer(data, functionNode);
- }
-
- // We don't emit a ScriptFunction on stack for the outermost compiled function (as there's no code being
- // generated in its outer context that'd need it as a callee).
- if (lc.getOutermostFunction() == functionNode) {
- return;
- }
-
- loadConstantsAndIndex(data, method);
-
- if (functionNode.needsParentScope()) {
- method.loadCompilerConstant(SCOPE);
- method.invoke(CREATE_FUNCTION_OBJECT);
- } else {
- method.invoke(CREATE_FUNCTION_OBJECT_NO_SCOPE);
- }
- }
-
- // calls on Global class.
- private MethodEmitter globalInstance() {
- return method.invokestatic(GLOBAL_OBJECT, "instance", "()L" + GLOBAL_OBJECT + ';');
- }
-
- private MethodEmitter globalAllocateArguments() {
- return method.invokestatic(GLOBAL_OBJECT, "allocateArguments", methodDescriptor(ScriptObject.class, Object[].class, Object.class, int.class));
- }
-
- private MethodEmitter globalNewRegExp() {
- return method.invokestatic(GLOBAL_OBJECT, "newRegExp", methodDescriptor(Object.class, String.class, String.class));
- }
-
- private MethodEmitter globalRegExpCopy() {
- return method.invokestatic(GLOBAL_OBJECT, "regExpCopy", methodDescriptor(Object.class, Object.class));
- }
-
- private MethodEmitter globalAllocateArray(final ArrayType type) {
- //make sure the native array is treated as an array type
- return method.invokestatic(GLOBAL_OBJECT, "allocate", "(" + type.getDescriptor() + ")Ljdk/nashorn/internal/objects/NativeArray;");
- }
-
- private MethodEmitter globalIsEval() {
- return method.invokestatic(GLOBAL_OBJECT, "isEval", methodDescriptor(boolean.class, Object.class));
- }
-
- private MethodEmitter globalReplaceLocationPropertyPlaceholder() {
- return method.invokestatic(GLOBAL_OBJECT, "replaceLocationPropertyPlaceholder", methodDescriptor(Object.class, Object.class, Object.class));
- }
-
- private MethodEmitter globalCheckObjectCoercible() {
- return method.invokestatic(GLOBAL_OBJECT, "checkObjectCoercible", methodDescriptor(void.class, Object.class));
- }
-
- private MethodEmitter globalDirectEval() {
- return method.invokestatic(GLOBAL_OBJECT, "directEval",
- methodDescriptor(Object.class, Object.class, Object.class, Object.class, Object.class, boolean.class));
- }
-
- private abstract class OptimisticOperation {
- final boolean isOptimistic;
- // expression and optimistic are the same reference
- private final Expression expression;
- private final Optimistic optimistic;
- private final TypeBounds resultBounds;
-
- OptimisticOperation(final Optimistic optimistic, final TypeBounds resultBounds) {
- this.optimistic = optimistic;
- this.expression = (Expression)optimistic;
- this.resultBounds = resultBounds;
- this.isOptimistic = isOptimistic(optimistic)
- // Operation is only effectively optimistic if its type, after being coerced into the result bounds
- // is narrower than the upper bound.
- && resultBounds.within(Type.generic(((Expression)optimistic).getType())).narrowerThan(resultBounds.widest);
- // Optimistic operations need to be executed in optimistic context, else unwarranted optimism will go unnoticed
- assert !this.isOptimistic || useOptimisticTypes();
- }
-
- MethodEmitter emit() {
- return emit(0);
- }
-
- MethodEmitter emit(final int ignoredArgCount) {
- final int programPoint = optimistic.getProgramPoint();
- final boolean optimisticOrContinuation = isOptimistic || isContinuationEntryPoint(programPoint);
- final boolean currentContinuationEntryPoint = isCurrentContinuationEntryPoint(programPoint);
- final int stackSizeOnEntry = method.getStackSize() - ignoredArgCount;
-
- // First store the values on the stack opportunistically into local variables. Doing it before loadStack()
- // allows us to not have to pop/load any arguments that are pushed onto it by loadStack() in the second
- // storeStack().
- storeStack(ignoredArgCount, optimisticOrContinuation);
-
- // Now, load the stack
- loadStack();
-
- // Now store the values on the stack ultimately into local variables. In vast majority of cases, this is
- // (aside from creating the local types map) a no-op, as the first opportunistic stack store will already
- // store all variables. However, there can be operations in the loadStack() that invalidate some of the
- // stack stores, e.g. in "x[i] = x[++i]", "++i" will invalidate the already stored value for "i". In such
- // unfortunate cases this second storeStack() will restore the invariant that everything on the stack is
- // stored into a local variable, although at the cost of doing a store/load on the loaded arguments as well.
- final int liveLocalsCount = storeStack(method.getStackSize() - stackSizeOnEntry, optimisticOrContinuation);
- assert optimisticOrContinuation == (liveLocalsCount != -1);
-
- final Label beginTry;
- final Label catchLabel;
- final Label afterConsumeStack = isOptimistic || currentContinuationEntryPoint ? new Label("after_consume_stack") : null;
- if(isOptimistic) {
- beginTry = new Label("try_optimistic");
- final String catchLabelName = (afterConsumeStack == null ? "" : afterConsumeStack.toString()) + "_handler";
- catchLabel = new Label(catchLabelName);
- method.label(beginTry);
- } else {
- beginTry = catchLabel = null;
- }
-
- consumeStack();
-
- if(isOptimistic) {
- method._try(beginTry, afterConsumeStack, catchLabel, UnwarrantedOptimismException.class);
- }
-
- if(isOptimistic || currentContinuationEntryPoint) {
- method.label(afterConsumeStack);
-
- final int[] localLoads = method.getLocalLoadsOnStack(0, stackSizeOnEntry);
- assert everyStackValueIsLocalLoad(localLoads) : Arrays.toString(localLoads) + ", " + stackSizeOnEntry + ", " + ignoredArgCount;
- final List localTypesList = method.getLocalVariableTypes();
- final int usedLocals = method.getUsedSlotsWithLiveTemporaries();
- final List localTypes = method.getWidestLiveLocals(localTypesList.subList(0, usedLocals));
- assert everyLocalLoadIsValid(localLoads, usedLocals) : Arrays.toString(localLoads) + " ~ " + localTypes;
-
- if(isOptimistic) {
- addUnwarrantedOptimismHandlerLabel(localTypes, catchLabel);
- }
- if(currentContinuationEntryPoint) {
- final ContinuationInfo ci = getContinuationInfo();
- assert ci != null : "no continuation info found for " + lc.getCurrentFunction();
- assert !ci.hasTargetLabel(); // No duplicate program points
- ci.setTargetLabel(afterConsumeStack);
- ci.getHandlerLabel().markAsOptimisticContinuationHandlerFor(afterConsumeStack);
- // Can't rely on targetLabel.stack.localVariableTypes.length, as it can be higher due to effectively
- // dead local variables.
- ci.lvarCount = localTypes.size();
- ci.setStackStoreSpec(localLoads);
- ci.setStackTypes(Arrays.copyOf(method.getTypesFromStack(method.getStackSize()), stackSizeOnEntry));
- assert ci.getStackStoreSpec().length == ci.getStackTypes().length;
- ci.setReturnValueType(method.peekType());
- ci.lineNumber = getLastLineNumber();
- ci.catchLabel = catchLabels.peek();
- }
- }
- return method;
- }
-
- /**
- * Stores the current contents of the stack into local variables so they are not lost before invoking something that
- * can result in an {@code UnwarantedOptimizationException}.
- * @param ignoreArgCount the number of topmost arguments on stack to ignore when deciding on the shape of the catch
- * block. Those are used in the situations when we could not place the call to {@code storeStack} early enough
- * (before emitting code for pushing the arguments that the optimistic call will pop). This is admittedly a
- * deficiency in the design of the code generator when it deals with self-assignments and we should probably look
- * into fixing it.
- * @return types of the significant local variables after the stack was stored (types for local variables used
- * for temporary storage of ignored arguments are not returned).
- * @param optimisticOrContinuation if false, this method should not execute
- * a label for a catch block for the {@code UnwarantedOptimizationException}, suitable for capturing the
- * currently live local variables, tailored to their types.
- */
- private int storeStack(final int ignoreArgCount, final boolean optimisticOrContinuation) {
- if(!optimisticOrContinuation) {
- return -1; // NOTE: correct value to return is lc.getUsedSlotCount(), but it wouldn't be used anyway
- }
-
- final int stackSize = method.getStackSize();
- final Type[] stackTypes = method.getTypesFromStack(stackSize);
- final int[] localLoadsOnStack = method.getLocalLoadsOnStack(0, stackSize);
- final int usedSlots = method.getUsedSlotsWithLiveTemporaries();
-
- final int firstIgnored = stackSize - ignoreArgCount;
- // Find the first value on the stack (from the bottom) that is not a load from a local variable.
- int firstNonLoad = 0;
- while(firstNonLoad < firstIgnored && localLoadsOnStack[firstNonLoad] != Label.Stack.NON_LOAD) {
- firstNonLoad++;
- }
-
- // Only do the store/load if first non-load is not an ignored argument. Otherwise, do nothing and return
- // the number of used slots as the number of live local variables.
- if(firstNonLoad >= firstIgnored) {
- return usedSlots;
- }
-
- // Find the number of new temporary local variables that we need; it's the number of values on the stack that
- // are not direct loads of existing local variables.
- int tempSlotsNeeded = 0;
- for(int i = firstNonLoad; i < stackSize; ++i) {
- if(localLoadsOnStack[i] == Label.Stack.NON_LOAD) {
- tempSlotsNeeded += stackTypes[i].getSlots();
- }
- }
-
- // Ensure all values on the stack that weren't directly loaded from a local variable are stored in a local
- // variable. We're starting from highest local variable index, so that in case ignoreArgCount > 0 the ignored
- // ones end up at the end of the local variable table.
- int lastTempSlot = usedSlots + tempSlotsNeeded;
- int ignoreSlotCount = 0;
- for(int i = stackSize; i -- > firstNonLoad;) {
- final int loadSlot = localLoadsOnStack[i];
- if(loadSlot == Label.Stack.NON_LOAD) {
- final Type type = stackTypes[i];
- final int slots = type.getSlots();
- lastTempSlot -= slots;
- if(i >= firstIgnored) {
- ignoreSlotCount += slots;
- }
- method.storeTemp(type, lastTempSlot);
- } else {
- method.pop();
- }
- }
- assert lastTempSlot == usedSlots; // used all temporary locals
-
- final List localTypesList = method.getLocalVariableTypes();
-
- // Load values back on stack.
- for(int i = firstNonLoad; i < stackSize; ++i) {
- final int loadSlot = localLoadsOnStack[i];
- final Type stackType = stackTypes[i];
- final boolean isLoad = loadSlot != Label.Stack.NON_LOAD;
- final int lvarSlot = isLoad ? loadSlot : lastTempSlot;
- final Type lvarType = localTypesList.get(lvarSlot);
- method.load(lvarType, lvarSlot);
- if(isLoad) {
- // Conversion operators (I2L etc.) preserve "load"-ness of the value despite the fact that, in the
- // strict sense they are creating a derived value from the loaded value. This special behavior of
- // on-stack conversion operators is necessary to accommodate for differences in local variable types
- // after deoptimization; having a conversion operator throw away "load"-ness would create different
- // local variable table shapes between optimism-failed code and its deoptimized rest-of method).
- // After we load the value back, we need to redo the conversion to the stack type if stack type is
- // different.
- // NOTE: this would only strictly be necessary for widening conversions (I2L, L2D, I2D), and not for
- // narrowing ones (L2I, D2L, D2I) as only widening conversions are the ones that can get eliminated
- // in a deoptimized method, as their original input argument got widened. Maybe experiment with
- // throwing away "load"-ness for narrowing conversions in MethodEmitter.convert()?
- method.convert(stackType);
- } else {
- // temporary stores never needs a convert, as their type is always the same as the stack type.
- assert lvarType == stackType;
- lastTempSlot += lvarType.getSlots();
- }
- }
- // used all temporaries
- assert lastTempSlot == usedSlots + tempSlotsNeeded;
-
- return lastTempSlot - ignoreSlotCount;
- }
-
- private void addUnwarrantedOptimismHandlerLabel(final List localTypes, final Label label) {
- final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes);
- final Map> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers();
- Collection labels = unwarrantedOptimismHandlers.get(lvarTypesDescriptor);
- if(labels == null) {
- labels = new LinkedList<>();
- unwarrantedOptimismHandlers.put(lvarTypesDescriptor, labels);
- }
- method.markLabelAsOptimisticCatchHandler(label, localTypes.size());
- labels.add(label);
- }
-
- abstract void loadStack();
-
- // Make sure that whatever indy call site you emit from this method uses {@code getCallSiteFlagsOptimistic(node)}
- // or otherwise ensure optimistic flag is correctly set in the call site, otherwise it doesn't make much sense
- // to use OptimisticExpression for emitting it.
- abstract void consumeStack();
-
- /**
- * Emits the correct dynamic getter code. Normally just delegates to method emitter, except when the target
- * expression is optimistic, and the desired type is narrower than the optimistic type. In that case, it'll emit a
- * dynamic getter with its original optimistic type, and explicitly insert a narrowing conversion. This way we can
- * preserve the optimism of the values even if they're subsequently immediately coerced into a narrower type. This
- * is beneficial because in this case we can still presume that since the original getter was optimistic, the
- * conversion has no side effects.
- * @param name the name of the property being get
- * @param flags call site flags
- * @param isMethod whether we're preferably retrieving a function
- * @return the current method emitter
- */
- MethodEmitter dynamicGet(final String name, final int flags, final boolean isMethod, final boolean isIndex) {
- if(isOptimistic) {
- return method.dynamicGet(getOptimisticCoercedType(), name, getOptimisticFlags(flags), isMethod, isIndex);
- }
- return method.dynamicGet(resultBounds.within(expression.getType()), name, nonOptimisticFlags(flags), isMethod, isIndex);
- }
-
- MethodEmitter dynamicGetIndex(final int flags, final boolean isMethod) {
- if(isOptimistic) {
- return method.dynamicGetIndex(getOptimisticCoercedType(), getOptimisticFlags(flags), isMethod);
- }
- return method.dynamicGetIndex(resultBounds.within(expression.getType()), nonOptimisticFlags(flags), isMethod);
- }
-
- MethodEmitter dynamicCall(final int argCount, final int flags, final String msg) {
- if (isOptimistic) {
- return method.dynamicCall(getOptimisticCoercedType(), argCount, getOptimisticFlags(flags), msg);
- }
- return method.dynamicCall(resultBounds.within(expression.getType()), argCount, nonOptimisticFlags(flags), msg);
- }
-
- int getOptimisticFlags(final int flags) {
- return flags | CALLSITE_OPTIMISTIC | (optimistic.getProgramPoint() << CALLSITE_PROGRAM_POINT_SHIFT); //encode program point in high bits
- }
-
- int getProgramPoint() {
- return isOptimistic ? optimistic.getProgramPoint() : INVALID_PROGRAM_POINT;
- }
-
- void convertOptimisticReturnValue() {
- if (isOptimistic) {
- final Type optimisticType = getOptimisticCoercedType();
- if(!optimisticType.isObject()) {
- method.load(optimistic.getProgramPoint());
- if(optimisticType.isInteger()) {
- method.invoke(ENSURE_INT);
- } else if(optimisticType.isNumber()) {
- method.invoke(ENSURE_NUMBER);
- } else {
- throw new AssertionError(optimisticType);
- }
- }
- }
- }
-
- void replaceCompileTimeProperty() {
- final IdentNode identNode = (IdentNode)expression;
- final String name = identNode.getSymbol().getName();
- if (CompilerConstants.__FILE__.name().equals(name)) {
- replaceCompileTimeProperty(getCurrentSource().getName());
- } else if (CompilerConstants.__DIR__.name().equals(name)) {
- replaceCompileTimeProperty(getCurrentSource().getBase());
- } else if (CompilerConstants.__LINE__.name().equals(name)) {
- replaceCompileTimeProperty(getCurrentSource().getLine(identNode.position()));
- }
- }
-
- /**
- * When an ident with name __FILE__, __DIR__, or __LINE__ is loaded, we'll try to look it up as any other
- * identifier. However, if it gets all the way up to the Global object, it will send back a special value that
- * represents a placeholder for these compile-time location properties. This method will generate code that loads
- * the value of the compile-time location property and then invokes a method in Global that will replace the
- * placeholder with the value. Effectively, if the symbol for these properties is defined anywhere in the lexical
- * scope, they take precedence, but if they aren't, then they resolve to the compile-time location property.
- * @param propertyValue the actual value of the property
- */
- private void replaceCompileTimeProperty(final Object propertyValue) {
- assert method.peekType().isObject();
- if(propertyValue instanceof String || propertyValue == null) {
- method.load((String)propertyValue);
- } else if(propertyValue instanceof Integer) {
- method.load(((Integer)propertyValue));
- method.convert(Type.OBJECT);
- } else {
- throw new AssertionError();
- }
- globalReplaceLocationPropertyPlaceholder();
- convertOptimisticReturnValue();
- }
-
- /**
- * Returns the type that should be used as the return type of the dynamic invocation that is emitted as the code
- * for the current optimistic operation. If the type bounds is exact boolean or narrower than the expression's
- * optimistic type, then the optimistic type is returned, otherwise the coercing type. Effectively, this method
- * allows for moving the coercion into the optimistic type when it won't adversely affect the optimistic
- * evaluation semantics, and for preserving the optimistic type and doing a separate coercion when it would
- * affect it.
- * @return
- */
- Type getOptimisticCoercedType() {
- final Type optimisticType = expression.getType();
- assert resultBounds.widest.widerThan(optimisticType);
- final Type narrowest = resultBounds.narrowest;
-
- if(narrowest.isBoolean() || narrowest.narrowerThan(optimisticType)) {
- assert !optimisticType.isObject();
- return optimisticType;
- }
- assert !narrowest.isObject();
- return narrowest;
- }
- }
-
- private static boolean isOptimistic(final Optimistic optimistic) {
- if(!optimistic.canBeOptimistic()) {
- return false;
- }
- final Expression expr = (Expression)optimistic;
- return expr.getType().narrowerThan(expr.getWidestOperationType());
- }
-
- private static boolean everyLocalLoadIsValid(final int[] loads, final int localCount) {
- for (final int load : loads) {
- if(load < 0 || load >= localCount) {
- return false;
- }
- }
- return true;
- }
-
- private static boolean everyStackValueIsLocalLoad(final int[] loads) {
- for (final int load : loads) {
- if(load == Label.Stack.NON_LOAD) {
- return false;
- }
- }
- return true;
- }
-
- private String getLvarTypesDescriptor(final List localVarTypes) {
- final int count = localVarTypes.size();
- final StringBuilder desc = new StringBuilder(count);
- for(int i = 0; i < count;) {
- i += appendType(desc, localVarTypes.get(i));
- }
- return method.markSymbolBoundariesInLvarTypesDescriptor(desc.toString());
- }
-
- private static int appendType(final StringBuilder b, final Type t) {
- b.append(t.getBytecodeStackType());
- return t.getSlots();
- }
-
- private static int countSymbolsInLvarTypeDescriptor(final String lvarTypeDescriptor) {
- int count = 0;
- for(int i = 0; i < lvarTypeDescriptor.length(); ++i) {
- if(Character.isUpperCase(lvarTypeDescriptor.charAt(i))) {
- ++count;
- }
- }
- return count;
-
- }
- /**
- * Generates all the required {@code UnwarrantedOptimismException} handlers for the current function. The employed
- * strategy strives to maximize code reuse. Every handler constructs an array to hold the local variables, then
- * fills in some trailing part of the local variables (those for which it has a unique suffix in the descriptor),
- * then jumps to a handler for a prefix that's shared with other handlers. A handler that fills up locals up to
- * position 0 will not jump to a prefix handler (as it has no prefix), but instead end with constructing and
- * throwing a {@code RewriteException}. Since we lexicographically sort the entries, we only need to check every
- * entry to its immediately preceding one for longest matching prefix.
- * @return true if there is at least one exception handler
- */
- private boolean generateUnwarrantedOptimismExceptionHandlers(final FunctionNode fn) {
- if(!useOptimisticTypes()) {
- return false;
- }
-
- // Take the mapping of lvarSpecs -> labels, and turn them into a descending lexicographically sorted list of
- // handler specifications.
- final Map> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers();
- if(unwarrantedOptimismHandlers.isEmpty()) {
- return false;
- }
-
- method.lineNumber(0);
-
- final List handlerSpecs = new ArrayList<>(unwarrantedOptimismHandlers.size() * 4/3);
- for(final String spec: unwarrantedOptimismHandlers.keySet()) {
- handlerSpecs.add(new OptimismExceptionHandlerSpec(spec, true));
- }
- Collections.sort(handlerSpecs, Collections.reverseOrder());
-
- // Map of local variable specifications to labels for populating the array for that local variable spec.
- final Map delegationLabels = new HashMap<>();
-
- // Do everything in a single pass over the handlerSpecs list. Note that the list can actually grow as we're
- // passing through it as we might add new prefix handlers into it, so can't hoist size() outside of the loop.
- for(int handlerIndex = 0; handlerIndex < handlerSpecs.size(); ++handlerIndex) {
- final OptimismExceptionHandlerSpec spec = handlerSpecs.get(handlerIndex);
- final String lvarSpec = spec.lvarSpec;
- if(spec.catchTarget) {
- assert !method.isReachable();
- // Start a catch block and assign the labels for this lvarSpec with it.
- method._catch(unwarrantedOptimismHandlers.get(lvarSpec));
- // This spec is a catch target, so emit array creation code. The length of the array is the number of
- // symbols - the number of uppercase characters.
- method.load(countSymbolsInLvarTypeDescriptor(lvarSpec));
- method.newarray(Type.OBJECT_ARRAY);
- }
- if(spec.delegationTarget) {
- // If another handler can delegate to this handler as its prefix, then put a jump target here for the
- // shared code (after the array creation code, which is never shared).
- method.label(delegationLabels.get(lvarSpec)); // label must exist
- }
-
- final boolean lastHandler = handlerIndex == handlerSpecs.size() - 1;
-
- int lvarIndex;
- final int firstArrayIndex;
- final int firstLvarIndex;
- Label delegationLabel;
- final String commonLvarSpec;
- if(lastHandler) {
- // Last handler block, doesn't delegate to anything.
- lvarIndex = 0;
- firstLvarIndex = 0;
- firstArrayIndex = 0;
- delegationLabel = null;
- commonLvarSpec = null;
- } else {
- // Not yet the last handler block, will definitely delegate to another handler; let's figure out which
- // one. It can be an already declared handler further down the list, or it might need to declare a new
- // prefix handler.
-
- // Since we're lexicographically ordered, the common prefix handler is defined by the common prefix of
- // this handler and the next handler on the list.
- final int nextHandlerIndex = handlerIndex + 1;
- final String nextLvarSpec = handlerSpecs.get(nextHandlerIndex).lvarSpec;
- commonLvarSpec = commonPrefix(lvarSpec, nextLvarSpec);
- // We don't chop symbols in half
- assert Character.isUpperCase(commonLvarSpec.charAt(commonLvarSpec.length() - 1));
-
- // Let's find if we already have a declaration for such handler, or we need to insert it.
- {
- boolean addNewHandler = true;
- int commonHandlerIndex = nextHandlerIndex;
- for(; commonHandlerIndex < handlerSpecs.size(); ++commonHandlerIndex) {
- final OptimismExceptionHandlerSpec forwardHandlerSpec = handlerSpecs.get(commonHandlerIndex);
- final String forwardLvarSpec = forwardHandlerSpec.lvarSpec;
- if(forwardLvarSpec.equals(commonLvarSpec)) {
- // We already have a handler for the common prefix.
- addNewHandler = false;
- // Make sure we mark it as a delegation target.
- forwardHandlerSpec.delegationTarget = true;
- break;
- } else if(!forwardLvarSpec.startsWith(commonLvarSpec)) {
- break;
- }
- }
- if(addNewHandler) {
- // We need to insert a common prefix handler. Note handlers created with catchTarget == false
- // will automatically have delegationTarget == true (because that's the only reason for their
- // existence).
- handlerSpecs.add(commonHandlerIndex, new OptimismExceptionHandlerSpec(commonLvarSpec, false));
- }
- }
-
- firstArrayIndex = countSymbolsInLvarTypeDescriptor(commonLvarSpec);
- lvarIndex = 0;
- for(int j = 0; j < commonLvarSpec.length(); ++j) {
- lvarIndex += CodeGeneratorLexicalContext.getTypeForSlotDescriptor(commonLvarSpec.charAt(j)).getSlots();
- }
- firstLvarIndex = lvarIndex;
-
- // Create a delegation label if not already present
- delegationLabel = delegationLabels.get(commonLvarSpec);
- if(delegationLabel == null) {
- // uo_pa == "unwarranted optimism, populate array"
- delegationLabel = new Label("uo_pa_" + commonLvarSpec);
- delegationLabels.put(commonLvarSpec, delegationLabel);
- }
- }
-
- // Load local variables handled by this handler on stack
- int args = 0;
- boolean symbolHadValue = false;
- for(int typeIndex = commonLvarSpec == null ? 0 : commonLvarSpec.length(); typeIndex < lvarSpec.length(); ++typeIndex) {
- final char typeDesc = lvarSpec.charAt(typeIndex);
- final Type lvarType = CodeGeneratorLexicalContext.getTypeForSlotDescriptor(typeDesc);
- if (!lvarType.isUnknown()) {
- method.load(lvarType, lvarIndex);
- symbolHadValue = true;
- args++;
- } else if(typeDesc == 'U' && !symbolHadValue) {
- // Symbol boundary with undefined last value. Check if all previous values for this symbol were also
- // undefined; if so, emit one explicit Undefined. This serves to ensure that we're emiting exactly
- // one value for every symbol that uses local slots. While we could in theory ignore symbols that
- // are undefined (in other words, dead) at the point where this exception was thrown, unfortunately
- // we can't do it in practice. The reason for this is that currently our liveness analysis is
- // coarse (it can determine whether a symbol has not been read with a particular type anywhere in
- // the function being compiled, but that's it), and a symbol being promoted to Object due to a
- // deoptimization will suddenly show up as "live for Object type", and previously dead U->O
- // conversions on loop entries will suddenly become alive in the deoptimized method which will then
- // expect a value for that slot in its continuation handler. If we had precise liveness analysis, we
- // could go back to excluding known dead symbols from the payload of the RewriteException.
- if(method.peekType() == Type.UNDEFINED) {
- method.dup();
- } else {
- method.loadUndefined(Type.OBJECT);
- }
- args++;
- }
- if(Character.isUpperCase(typeDesc)) {
- // Reached symbol boundary; reset flag for the next symbol.
- symbolHadValue = false;
- }
- lvarIndex += lvarType.getSlots();
- }
- assert args > 0;
- // Delegate actual storing into array to an array populator utility method.
- //on the stack:
- // object array to be populated
- // start index
- // a lot of types
- method.dynamicArrayPopulatorCall(args + 1, firstArrayIndex);
- if(delegationLabel != null) {
- // We cascade to a prefix handler to fill out the rest of the local variables and throw the
- // RewriteException.
- assert !lastHandler;
- assert commonLvarSpec != null;
- // Must undefine the local variables that we have already processed for the sake of correct join on the
- // delegate label
- method.undefineLocalVariables(firstLvarIndex, true);
- final OptimismExceptionHandlerSpec nextSpec = handlerSpecs.get(handlerIndex + 1);
- // If the delegate immediately follows, and it's not a catch target (so it doesn't have array setup
- // code) don't bother emitting a jump, as we'd just jump to the next instruction.
- if(!nextSpec.lvarSpec.equals(commonLvarSpec) || nextSpec.catchTarget) {
- method._goto(delegationLabel);
- }
- } else {
- assert lastHandler;
- // Nothing to delegate to, so this handler must create and throw the RewriteException.
- // At this point we have the UnwarrantedOptimismException and the Object[] with local variables on
- // stack. We need to create a RewriteException, push two references to it below the constructor
- // arguments, invoke the constructor, and throw the exception.
- loadConstant(getByteCodeSymbolNames(fn));
- if (isRestOf()) {
- loadConstant(getContinuationEntryPoints());
- method.invoke(CREATE_REWRITE_EXCEPTION_REST_OF);
- } else {
- method.invoke(CREATE_REWRITE_EXCEPTION);
- }
- method.athrow();
- }
- }
- return true;
- }
-
- private static String[] getByteCodeSymbolNames(final FunctionNode fn) {
- // Only names of local variables on the function level are captured. This information is used to reduce
- // deoptimizations, so as much as we can capture will help. We rely on the fact that function wide variables are
- // all live all the time, so the array passed to rewrite exception contains one element for every slotted symbol
- // here.
- final List names = new ArrayList<>();
- for (final Symbol symbol: fn.getBody().getSymbols()) {
- if (symbol.hasSlot()) {
- if (symbol.isScope()) {
- // slot + scope can only be true for parameters
- assert symbol.isParam();
- names.add(null);
- } else {
- names.add(symbol.getName());
- }
- }
- }
- return names.toArray(new String[0]);
- }
-
- private static String commonPrefix(final String s1, final String s2) {
- final int l1 = s1.length();
- final int l = Math.min(l1, s2.length());
- int lms = -1; // last matching symbol
- for(int i = 0; i < l; ++i) {
- final char c1 = s1.charAt(i);
- if(c1 != s2.charAt(i)) {
- return s1.substring(0, lms + 1);
- } else if(Character.isUpperCase(c1)) {
- lms = i;
- }
- }
- return l == l1 ? s1 : s2;
- }
-
- private static class OptimismExceptionHandlerSpec implements Comparable {
- private final String lvarSpec;
- private final boolean catchTarget;
- private boolean delegationTarget;
-
- OptimismExceptionHandlerSpec(final String lvarSpec, final boolean catchTarget) {
- this.lvarSpec = lvarSpec;
- this.catchTarget = catchTarget;
- if(!catchTarget) {
- delegationTarget = true;
- }
- }
-
- @Override
- public int compareTo(final OptimismExceptionHandlerSpec o) {
- return lvarSpec.compareTo(o.lvarSpec);
- }
-
- @Override
- public String toString() {
- final StringBuilder b = new StringBuilder(64).append("[HandlerSpec ").append(lvarSpec);
- if(catchTarget) {
- b.append(", catchTarget");
- }
- if(delegationTarget) {
- b.append(", delegationTarget");
- }
- return b.append("]").toString();
- }
- }
-
- private static class ContinuationInfo {
- private final Label handlerLabel;
- private Label targetLabel; // Label for the target instruction.
- int lvarCount;
- // Indices of local variables that need to be loaded on the stack when this node completes
- private int[] stackStoreSpec;
- // Types of values loaded on the stack
- private Type[] stackTypes;
- // If non-null, this node should perform the requisite type conversion
- private Type returnValueType;
- // If we are in the middle of an object literal initialization, we need to update the property maps
- private Map objectLiteralMaps;
- // The line number at the continuation point
- private int lineNumber;
- // The active catch label, in case the continuation point is in a try/catch block
- private Label catchLabel;
- // The number of scopes that need to be popped before control is transferred to the catch label.
- private int exceptionScopePops;
-
- ContinuationInfo() {
- this.handlerLabel = new Label("continuation_handler");
- }
-
- Label getHandlerLabel() {
- return handlerLabel;
- }
-
- boolean hasTargetLabel() {
- return targetLabel != null;
- }
-
- Label getTargetLabel() {
- return targetLabel;
- }
-
- void setTargetLabel(final Label targetLabel) {
- this.targetLabel = targetLabel;
- }
-
- int[] getStackStoreSpec() {
- return stackStoreSpec.clone();
- }
-
- void setStackStoreSpec(final int[] stackStoreSpec) {
- this.stackStoreSpec = stackStoreSpec;
- }
-
- Type[] getStackTypes() {
- return stackTypes.clone();
- }
-
- void setStackTypes(final Type[] stackTypes) {
- this.stackTypes = stackTypes;
- }
-
- Type getReturnValueType() {
- return returnValueType;
- }
-
- void setReturnValueType(final Type returnValueType) {
- this.returnValueType = returnValueType;
- }
-
- void setObjectLiteralMap(final int objectLiteralStackDepth, final PropertyMap objectLiteralMap) {
- if (objectLiteralMaps == null) {
- objectLiteralMaps = new HashMap<>();
- }
- objectLiteralMaps.put(objectLiteralStackDepth, objectLiteralMap);
- }
-
- PropertyMap getObjectLiteralMap(final int stackDepth) {
- return objectLiteralMaps == null ? null : objectLiteralMaps.get(stackDepth);
- }
-
- @Override
- public String toString() {
- return "[localVariableTypes=" + targetLabel.getStack().getLocalVariableTypesCopy() + ", stackStoreSpec=" +
- Arrays.toString(stackStoreSpec) + ", returnValueType=" + returnValueType + "]";
- }
- }
-
- private ContinuationInfo getContinuationInfo() {
- return continuationInfo;
- }
-
- private void generateContinuationHandler() {
- if (!isRestOf()) {
- return;
- }
-
- final ContinuationInfo ci = getContinuationInfo();
- method.label(ci.getHandlerLabel());
-
- // There should never be an exception thrown from the continuation handler, but in case there is (meaning,
- // Nashorn has a bug), then line number 0 will be an indication of where it came from (line numbers are Uint16).
- method.lineNumber(0);
-
- final Label.Stack stack = ci.getTargetLabel().getStack();
- final List lvarTypes = stack.getLocalVariableTypesCopy();
- final BitSet symbolBoundary = stack.getSymbolBoundaryCopy();
- final int lvarCount = ci.lvarCount;
-
- final Type rewriteExceptionType = Type.typeFor(RewriteException.class);
- // Store the RewriteException into an unused local variable slot.
- method.load(rewriteExceptionType, 0);
- method.storeTemp(rewriteExceptionType, lvarCount);
- // Get local variable array
- method.load(rewriteExceptionType, 0);
- method.invoke(RewriteException.GET_BYTECODE_SLOTS);
- // Store local variables. Note that deoptimization might introduce new value types for existing local variables,
- // so we must use both liveLocals and symbolBoundary, as in some cases (when the continuation is inside of a try
- // block) we need to store the incoming value into multiple slots. The optimism exception handlers will have
- // exactly one array element for every symbol that uses bytecode storage. If in the originating method the value
- // was undefined, there will be an explicit Undefined value in the array.
- int arrayIndex = 0;
- for(int lvarIndex = 0; lvarIndex < lvarCount;) {
- final Type lvarType = lvarTypes.get(lvarIndex);
- if(!lvarType.isUnknown()) {
- method.dup();
- method.load(arrayIndex).arrayload();
- final Class typeClass = lvarType.getTypeClass();
- // Deoptimization in array initializers can cause arrays to undergo component type widening
- if(typeClass == long[].class) {
- method.load(rewriteExceptionType, lvarCount);
- method.invoke(RewriteException.TO_LONG_ARRAY);
- } else if(typeClass == double[].class) {
- method.load(rewriteExceptionType, lvarCount);
- method.invoke(RewriteException.TO_DOUBLE_ARRAY);
- } else if(typeClass == Object[].class) {
- method.load(rewriteExceptionType, lvarCount);
- method.invoke(RewriteException.TO_OBJECT_ARRAY);
- } else {
- if(!(typeClass.isPrimitive() || typeClass == Object.class)) {
- // NOTE: this can only happen with dead stores. E.g. for the program "1; []; f();" in which the
- // call to f() will deoptimize the call site, but it'll expect :return to have the type
- // NativeArray. However, in the more optimal version, :return's only live type is int, therefore
- // "{O}:return = []" is a dead store, and the variable will be sent into the continuation as
- // Undefined, however NativeArray can't hold Undefined instance.
- method.loadType(Type.getInternalName(typeClass));
- method.invoke(RewriteException.INSTANCE_OR_NULL);
- }
- method.convert(lvarType);
- }
- method.storeHidden(lvarType, lvarIndex, false);
- }
- final int nextLvarIndex = lvarIndex + lvarType.getSlots();
- if(symbolBoundary.get(nextLvarIndex - 1)) {
- ++arrayIndex;
- }
- lvarIndex = nextLvarIndex;
- }
- if (AssertsEnabled.assertsEnabled()) {
- method.load(arrayIndex);
- method.invoke(RewriteException.ASSERT_ARRAY_LENGTH);
- } else {
- method.pop();
- }
-
- final int[] stackStoreSpec = ci.getStackStoreSpec();
- final Type[] stackTypes = ci.getStackTypes();
- final boolean isStackEmpty = stackStoreSpec.length == 0;
- int replacedObjectLiteralMaps = 0;
- if(!isStackEmpty) {
- // Load arguments on the stack
- for(int i = 0; i < stackStoreSpec.length; ++i) {
- final int slot = stackStoreSpec[i];
- method.load(lvarTypes.get(slot), slot);
- method.convert(stackTypes[i]);
- // stack: s0=object literal being initialized
- // change map of s0 so that the property we are initializing when we failed
- // is now ci.returnValueType
- final PropertyMap map = ci.getObjectLiteralMap(i);
- if (map != null) {
- method.dup();
- assert ScriptObject.class.isAssignableFrom(method.peekType().getTypeClass()) : method.peekType().getTypeClass() + " is not a script object";
- loadConstant(map);
- method.invoke(ScriptObject.SET_MAP);
- replacedObjectLiteralMaps++;
- }
- }
- }
- // Must have emitted the code for replacing all object literal maps
- assert ci.objectLiteralMaps == null || ci.objectLiteralMaps.size() == replacedObjectLiteralMaps;
- // Load RewriteException back.
- method.load(rewriteExceptionType, lvarCount);
- // Get rid of the stored reference
- method.loadNull();
- method.storeHidden(Type.OBJECT, lvarCount);
- // Mark it dead
- method.markDeadSlots(lvarCount, Type.OBJECT.getSlots());
-
- // Load return value on the stack
- method.invoke(RewriteException.GET_RETURN_VALUE);
-
- final Type returnValueType = ci.getReturnValueType();
-
- // Set up an exception handler for primitive type conversion of return value if needed
- boolean needsCatch = false;
- final Label targetCatchLabel = ci.catchLabel;
- Label _try = null;
- if(returnValueType.isPrimitive()) {
- // If the conversion throws an exception, we want to report the line number of the continuation point.
- method.lineNumber(ci.lineNumber);
-
- if(targetCatchLabel != METHOD_BOUNDARY) {
- _try = new Label("");
- method.label(_try);
- needsCatch = true;
- }
- }
-
- // Convert return value
- method.convert(returnValueType);
-
- final int scopePopCount = needsCatch ? ci.exceptionScopePops : 0;
-
- // Declare a try/catch for the conversion. If no scopes need to be popped until the target catch block, just
- // jump into it. Otherwise, we'll need to create a scope-popping catch block below.
- final Label catchLabel = scopePopCount > 0 ? new Label("") : targetCatchLabel;
- if(needsCatch) {
- final Label _end_try = new Label("");
- method.label(_end_try);
- method._try(_try, _end_try, catchLabel);
- }
-
- // Jump to continuation point
- method._goto(ci.getTargetLabel());
-
- // Make a scope-popping exception delegate if needed
- if(catchLabel != targetCatchLabel) {
- method.lineNumber(0);
- assert scopePopCount > 0;
- method._catch(catchLabel);
- popScopes(scopePopCount);
- method.uncheckedGoto(targetCatchLabel);
- }
- }
-
- /**
- * Interface implemented by object creators that support splitting over multiple methods.
- */
- interface SplitLiteralCreator {
- /**
- * Generate code to populate a range of the literal object. A reference to the object
- * should be left on the stack when the method terminates.
- *
- * @param method the method emitter
- * @param type the type of the literal object
- * @param slot the local slot containing the literal object
- * @param start the start index (inclusive)
- * @param end the end index (exclusive)
- */
- void populateRange(MethodEmitter method, Type type, int slot, int start, int end);
- }
-}