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Diffstat (limited to 'src/jdk/nashorn/internal/codegen/CodeGenerator.java')
| -rw-r--r-- | src/jdk/nashorn/internal/codegen/CodeGenerator.java | 5499 |
1 files changed, 0 insertions, 5499 deletions
diff --git a/src/jdk/nashorn/internal/codegen/CodeGenerator.java b/src/jdk/nashorn/internal/codegen/CodeGenerator.java deleted file mode 100644 index 6b9b731f..00000000 --- a/src/jdk/nashorn/internal/codegen/CodeGenerator.java +++ /dev/null @@ -1,5499 +0,0 @@ -/* - * Copyright (c) 2010, 2013, 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.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 - * <pre> - * if (type == INT) { - * visitInsn(ILOAD, slot); - * } else if (type == DOUBLE) { - * visitInsn(DOUBLE, slot); - * } - * </pre> - * This quickly became apparent when the code generator was generalized to work - * with all types, and not just numbers or objects. - * <p> - * The CodeGenerator visits nodes only once and emits bytecode for them. - */ -@Logger(name="codegen") -final class CodeGenerator extends NodeOperatorVisitor<CodeGeneratorLexicalContext> 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 = Integer.valueOf(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<String> emittedMethods = new HashSet<>(); - - // Function Id -> ContinuationInfo. Used by compilation of rest-of function only. - private ContinuationInfo continuationInfo; - - private final Deque<Label> scopeEntryLabels = new ArrayDeque<>(); - - private static final Label METHOD_BOUNDARY = new Label(""); - private final Deque<Label> 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; - - /** - * 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)) { - // Only generate shared scope getter for fast-scope symbols so we know we can dial in correct scope. - if (symbol.getUseCount() > SharedScopeCall.FAST_SCOPE_GET_THRESHOLD && !identNode.isOptimistic()) { - // As shared scope vars are only used with non-optimistic identifiers, we switch from using TypeBounds to - // just a single definitive type, resultBounds.widest. - new OptimisticOperation(identNode, TypeBounds.OBJECT) { - @Override - void loadStack() { - method.loadCompilerConstant(SCOPE); - } - - @Override - void consumeStack() { - loadSharedScopeVar(resultBounds.widest, symbol, flags); - } - }.emit(); - } else { - new LoadFastScopeVar(identNode, resultBounds, flags).emit(); - } - } else { - //slow scope load, we have no proto depth - new LoadScopeVar(identNode, resultBounds, flags).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<LexicalContextNode> 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 MethodEmitter loadSharedScopeVar(final Type valueType, final Symbol symbol, final int flags) { - assert isFastScope(symbol); - method.load(getScopeProtoDepth(lc.getCurrentBlock(), symbol)); - return lc.getScopeGet(unit, symbol, valueType, flags).generateInvoke(method); - } - - 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(); - } - for (int i = 0; i < depth; i++) { - method.invoke(ScriptObject.GET_PROTO); - } - if (swap) { - method.swap(); - } - } - } - - /** - * 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 dyn:getProp|getElem|getMethod:size(Object;)D - // instead of the more costly: - // invokedynamic dyn:getProp|getElem|getMethod: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 final 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<LexicalContext>(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 enterSUB(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 enterCOMMALEFT(final BinaryNode binaryNode) { - loadCOMMALEFT(binaryNode, resultBounds); - 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 enterADD(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 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.inSplitNode() && 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.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); - for(int i = 0; i < count; ++i) { - method.invoke(ScriptObject.GET_PROTO); - } - 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<Expression> 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<Expression> 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(); - final boolean isFastScope = isFastScope(symbol); - new OptimisticOperation(callNode, resultBounds) { - @Override - void loadStack() { - method.loadCompilerConstant(SCOPE); - if (isFastScope) { - method.load(getScopeProtoDepth(currentBlock, symbol)); - } else { - method.load(-1); // Bypass fast-scope code in shared callsite - } - 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]); - } - // As shared scope calls are only used in non-optimistic compilation, we switch from using - // TypeBounds to just a single definitive type, resultBounds.widest. - final SharedScopeCall scopeCall = codegenLexicalContext.getScopeCall(unit, symbol, - identNode.getType(), resultBounds.widest, paramTypes, flags); - 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, dyn:getMethod|getProp|getElem - * 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 "dyn:getProp|getElem|getMethod" 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<Expression> 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 dyn:getMethod|getProp|getElem - 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(); - - // Threshold for generating shared scope callsite is lower for fast scope symbols because we know - // we can dial in the correct scope. However, we also need to enable it for non-fast scopes to - // support huge scripts like mandreel.js. - if (callNode.isEval()) { - evalCall(node, flags); - } else if (useCount <= SharedScopeCall.FAST_SCOPE_CALL_THRESHOLD - || !isFastScope(symbol) && useCount <= SharedScopeCall.SLOW_SCOPE_CALL_THRESHOLD - || CodeGenerator.this.lc.inDynamicScope() - || callNode.isOptimistic()) { - 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.isForIn()) { - 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); - method.invoke(forNode.isForEach() ? ScriptRuntime.TO_VALUE_ITERATOR : ScriptRuntime.TO_PROPERTY_ITERATOR); - 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<Expression>(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(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<MapTuple<Symbol>> tuples = new ArrayList<>(); - final Iterator<IdentNode> 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>(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>(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 - */ - new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) { - @Override - protected void loadValue(final Symbol value, final Type type) { - method.load(value, type); - } - }.makeObject(method); - // 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 ? "<anonymous>" : 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<IdentNode> 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<Splittable.SplitRange> 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<Expression> 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>() { - 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<PropertyNode> elements = objectNode.getElements(); - - final List<MapTuple<Expression>> tuples = new ArrayList<>(); - final List<PropertyNode> gettersSetters = new ArrayList<>(); - final int ccp = getCurrentContinuationEntryPoint(); - final List<Splittable.SplitRange> ranges = objectNode.getSplitRanges(); - - Expression protoNode = null; - boolean restOfProperty = false; - - for (final PropertyNode propertyNode : elements) { - final Expression value = propertyNode.getValue(); - final String key = propertyNode.getKeyName(); - // Just use a pseudo-symbol. We just need something non null; use the name and zero flags. - final Symbol symbol = value == null ? null : new Symbol(key, 0); - - if (value == null) { - gettersSetters.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() || value == null || value.getType().isBoolean()) ? Object.class : value.getType().getTypeClass(); - tuples.add(new MapTuple<Expression>(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<Expression>(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 : gettersSetters) { - final FunctionNode getter = propertyNode.getGetter(); - final FunctionNode setter = propertyNode.getSetter(); - - assert getter != null || setter != null; - - method.dup().loadKey(propertyNode.getKey()); - 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<Expression> 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(isDeoptimizedExpression(lhs)) { - // This is actually related to "lhs.getType().isPrimitive()" above: any expression being deoptimized in - // the current chain of rest-of compilations used to have a type narrower than Object (so it was primitive). - // 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<Expression> 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(isDeoptimizedExpression(lhs)) { - // This is actually related to "!lhs.getType().isObject()" above: any expression being deoptimized in - // the current chain of rest-of compilations used to have a type narrower than Object. 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; - } - - /** - * Was this expression or any of its subexpressions deoptimized in the current recompilation chain of rest-of methods? - * @param rootExpr the expression being tested - * @return true if the expression or any of its subexpressions was deoptimized in the current recompilation chain. - */ - private boolean isDeoptimizedExpression(final Expression rootExpr) { - if(!isRestOf()) { - return false; - } - return new Supplier<Boolean>() { - 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) && isContinuationEntryPoint(pp); - } - return !contains; - } - }); - return contains; - } - }.get(); - } - - private void loadRuntimeNode(final RuntimeNode runtimeNode) { - final List<Expression> 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<Splittable.SplitRange> 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.enterSplitNode(); - - creator.populateRange(method, literalType, literalSlot, splitRange.getLow(), splitRange.getHigh()); - - method._return(); - lc.exitSplitNode(); - 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<CaseNode> 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<Integer, Label> 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[size]); - final Label[] labels = tree.values().toArray(new Label[size]); - - // 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-<init>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<Block> 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.getException(); - final Expression exceptionCondition = catchNode.getExceptionCondition(); - final Block catchBody = catchNode.getBody(); - - new Store<IdentNode>(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) { - if (needsScope && varNode.isBlockScoped()) { - // block scoped variables need a DECLARE flag to signal end of temporal dead zone (TDZ) - method.loadCompilerConstant(SCOPE); - method.loadUndefined(Type.OBJECT); - final int flags = getScopeCallSiteFlags(identSymbol) | (varNode.isBlockScoped() ? CALLSITE_DECLARE : 0); - assert isFastScope(identSymbol); - storeFastScopeVar(identSymbol, flags); - } - return false; - } - - enterStatement(varNode); - assert method != null; - - if (needsScope) { - method.loadCompilerConstant(SCOPE); - } - - if (needsScope) { - 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>(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<Expression> 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 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>(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<BinaryNode> { - - /** - * 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<BinaryNode> { - 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, 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 loadCOMMALEFT(final BinaryNode binaryNode, final TypeBounds resultBounds) { - loadMaybeDiscard(binaryNode, binaryNode.lhs(), resultBounds); - loadAndDiscard(binaryNode.rhs()); - } - - 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.getFlag(FunctionNode.IS_PRINT_SYMBOLS)) { - final PrintWriter out = compiler.getScriptEnvironment().getErr(); - out.println("[BLOCK in '" + ident + "']"); - if (!block.printSymbols(out)) { - out.println("<no symbols>"); - } - 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 <T> - */ - private abstract class SelfModifyingStore<T extends Expression> extends Store<T> { - 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<T extends Expression> { - - /** 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); - 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 { - private 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) && useOptimisticTypes() && - // 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); - } - - 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<Type> localTypesList = method.getLocalVariableTypes(); - final int usedLocals = method.getUsedSlotsWithLiveTemporaries(); - final List<Type> 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<Type> 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<Type> localTypes, final Label label) { - final String lvarTypesDescriptor = getLvarTypesDescriptor(localTypes); - final Map<String, Collection<Label>> unwarrantedOptimismHandlers = lc.getUnwarrantedOptimismHandlers(); - Collection<Label> 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).intValue()); - 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 - */ - private 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<Type> 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<String, Collection<Label>> unwarrantedOptimismHandlers = lc.popUnwarrantedOptimismHandlers(); - if(unwarrantedOptimismHandlers.isEmpty()) { - return false; - } - - method.lineNumber(0); - - final List<OptimismExceptionHandlerSpec> 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<String, Label> 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<String> 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[names.size()]); - } - - 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<OptimismExceptionHandlerSpec> { - 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<Integer, PropertyMap> 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<Type> 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); - } -} |