| /******************************************************************************* |
| * Copyright (c) 2000, 2011 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| * Stephan Herrmann - Contribution for bug 335093 - [compiler][null] minimal hook for future null annotation support |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.compiler.ast; |
| |
| import org.eclipse.jdt.internal.compiler.codegen.*; |
| import org.eclipse.jdt.internal.compiler.flow.*; |
| import org.eclipse.jdt.internal.compiler.impl.Constant; |
| import org.eclipse.jdt.internal.compiler.lookup.*; |
| |
| public abstract class Statement extends ASTNode { |
| |
| /** |
| * Answers true if the if is identified as a known coding pattern which |
| * should be tolerated by dead code analysis. |
| * e.g. if (DEBUG) print(); // no complaint |
| * Only invoked when overall condition is known to be optimizeable into false/true. |
| */ |
| protected static boolean isKnowDeadCodePattern(Expression expression) { |
| // if (!DEBUG) print(); - tolerated |
| if (expression instanceof UnaryExpression) { |
| expression = ((UnaryExpression) expression).expression; |
| } |
| // if (DEBUG) print(); - tolerated |
| if (expression instanceof Reference) return true; |
| |
| // if (expression instanceof BinaryExpression) { |
| // BinaryExpression binary = (BinaryExpression) expression; |
| // switch ((binary.bits & ASTNode.OperatorMASK) >> ASTNode.OperatorSHIFT/* operator */) { |
| // case OperatorIds.AND_AND : |
| // case OperatorIds.OR_OR : |
| // break; |
| // default: |
| // // if (DEBUG_LEVEL > 0) print(); - tolerated |
| // if ((binary.left instanceof Reference) && binary.right.constant != Constant.NotAConstant) |
| // return true; |
| // // if (0 < DEBUG_LEVEL) print(); - tolerated |
| // if ((binary.right instanceof Reference) && binary.left.constant != Constant.NotAConstant) |
| // return true; |
| // } |
| // } |
| return false; |
| } |
| public abstract FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo); |
| |
| public static final int NOT_COMPLAINED = 0; |
| public static final int COMPLAINED_FAKE_REACHABLE = 1; |
| public static final int COMPLAINED_UNREACHABLE = 2; |
| |
| /** Empty hook for checking null status against declaration using null annotations, once this will be supported. */ |
| protected int checkAgainstNullAnnotation(BlockScope currentScope, LocalVariableBinding local, int nullStatus) { |
| return nullStatus; |
| } |
| |
| /** |
| * INTERNAL USE ONLY. |
| * This is used to redirect inter-statements jumps. |
| */ |
| public void branchChainTo(BranchLabel label) { |
| // do nothing by default |
| } |
| |
| // Report an error if necessary (if even more unreachable than previously reported |
| // complaintLevel = 0 if was reachable up until now, 1 if fake reachable (deadcode), 2 if fatal unreachable (error) |
| public int complainIfUnreachable(FlowInfo flowInfo, BlockScope scope, int previousComplaintLevel) { |
| if ((flowInfo.reachMode() & FlowInfo.UNREACHABLE) != 0) { |
| if ((flowInfo.reachMode() & FlowInfo.UNREACHABLE_OR_DEAD) != 0) |
| this.bits &= ~ASTNode.IsReachable; |
| if (flowInfo == FlowInfo.DEAD_END) { |
| if (previousComplaintLevel < COMPLAINED_UNREACHABLE) { |
| scope.problemReporter().unreachableCode(this); |
| } |
| return COMPLAINED_UNREACHABLE; |
| } else { |
| if (previousComplaintLevel < COMPLAINED_FAKE_REACHABLE) { |
| scope.problemReporter().fakeReachable(this); |
| } |
| return COMPLAINED_FAKE_REACHABLE; |
| } |
| } |
| return previousComplaintLevel; |
| } |
| |
| /** |
| * Generate invocation arguments, considering varargs methods |
| */ |
| public void generateArguments(MethodBinding binding, Expression[] arguments, BlockScope currentScope, CodeStream codeStream) { |
| if (binding.isVarargs()) { |
| // 5 possibilities exist for a call to the vararg method foo(int i, int ... value) : |
| // foo(1), foo(1, null), foo(1, 2), foo(1, 2, 3, 4) & foo(1, new int[] {1, 2}) |
| TypeBinding[] params = binding.parameters; |
| int paramLength = params.length; |
| int varArgIndex = paramLength - 1; |
| for (int i = 0; i < varArgIndex; i++) { |
| arguments[i].generateCode(currentScope, codeStream, true); |
| } |
| ArrayBinding varArgsType = (ArrayBinding) params[varArgIndex]; // parameterType has to be an array type |
| ArrayBinding codeGenVarArgsType = (ArrayBinding) binding.parameters[varArgIndex].erasure(); |
| int elementsTypeID = varArgsType.elementsType().id; |
| int argLength = arguments == null ? 0 : arguments.length; |
| |
| if (argLength > paramLength) { |
| // right number but not directly compatible or too many arguments - wrap extra into array |
| // called with (argLength - lastIndex) elements : foo(1, 2) or foo(1, 2, 3, 4) |
| // need to gen elements into an array, then gen each remaining element into created array |
| codeStream.generateInlinedValue(argLength - varArgIndex); |
| codeStream.newArray(codeGenVarArgsType); // create a mono-dimensional array |
| for (int i = varArgIndex; i < argLength; i++) { |
| codeStream.dup(); |
| codeStream.generateInlinedValue(i - varArgIndex); |
| arguments[i].generateCode(currentScope, codeStream, true); |
| codeStream.arrayAtPut(elementsTypeID, false); |
| } |
| } else if (argLength == paramLength) { |
| // right number of arguments - could be inexact - pass argument as is |
| TypeBinding lastType = arguments[varArgIndex].resolvedType; |
| if (lastType == TypeBinding.NULL |
| || (varArgsType.dimensions() == lastType.dimensions() |
| && lastType.isCompatibleWith(varArgsType))) { |
| // foo(1, new int[]{2, 3}) or foo(1, null) --> last arg is passed as-is |
| arguments[varArgIndex].generateCode(currentScope, codeStream, true); |
| } else { |
| // right number but not directly compatible or too many arguments - wrap extra into array |
| // need to gen elements into an array, then gen each remaining element into created array |
| codeStream.generateInlinedValue(1); |
| codeStream.newArray(codeGenVarArgsType); // create a mono-dimensional array |
| codeStream.dup(); |
| codeStream.generateInlinedValue(0); |
| arguments[varArgIndex].generateCode(currentScope, codeStream, true); |
| codeStream.arrayAtPut(elementsTypeID, false); |
| } |
| } else { // not enough arguments - pass extra empty array |
| // scenario: foo(1) --> foo(1, new int[0]) |
| // generate code for an empty array of parameterType |
| codeStream.generateInlinedValue(0); |
| codeStream.newArray(codeGenVarArgsType); // create a mono-dimensional array |
| } |
| } else if (arguments != null) { // standard generation for method arguments |
| for (int i = 0, max = arguments.length; i < max; i++) |
| arguments[i].generateCode(currentScope, codeStream, true); |
| } |
| } |
| |
| public abstract void generateCode(BlockScope currentScope, CodeStream codeStream); |
| |
| protected boolean isBoxingCompatible(TypeBinding expressionType, TypeBinding targetType, Expression expression, Scope scope) { |
| if (scope.isBoxingCompatibleWith(expressionType, targetType)) |
| return true; |
| |
| return expressionType.isBaseType() // narrowing then boxing ? |
| && !targetType.isBaseType() |
| && !targetType.isTypeVariable() |
| && scope.compilerOptions().sourceLevel >= org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants.JDK1_5 // autoboxing |
| && expression.isConstantValueOfTypeAssignableToType(expressionType, scope.environment().computeBoxingType(targetType)); |
| } |
| |
| public boolean isEmptyBlock() { |
| return false; |
| } |
| |
| public boolean isValidJavaStatement() { |
| //the use of this method should be avoid in most cases |
| //and is here mostly for documentation purpose..... |
| //while the parser is responsible for creating |
| //welled formed expression statement, which results |
| //in the fact that java-non-semantic-expression-used-as-statement |
| //should not be parsed...thus not being built. |
| //It sounds like the java grammar as help the compiler job in removing |
| //-by construction- some statement that would have no effect.... |
| //(for example all expression that may do side-effects are valid statement |
| // -this is an approximative idea.....-) |
| |
| return true; |
| } |
| |
| public StringBuffer print(int indent, StringBuffer output) { |
| return printStatement(indent, output); |
| } |
| |
| public abstract StringBuffer printStatement(int indent, StringBuffer output); |
| |
| public abstract void resolve(BlockScope scope); |
| |
| /** |
| * Returns case constant associated to this statement (NotAConstant if none) |
| */ |
| public Constant resolveCase(BlockScope scope, TypeBinding testType, SwitchStatement switchStatement) { |
| // statement within a switch that are not case are treated as normal statement.... |
| resolve(scope); |
| return Constant.NotAConstant; |
| } |
| /** |
| * Implementation of {@link org.eclipse.jdt.internal.compiler.lookup.InvocationSite#expectedType} |
| * suitable at this level. Subclasses should override as necessary. |
| * @see org.eclipse.jdt.internal.compiler.lookup.InvocationSite#expectedType() |
| */ |
| public TypeBinding expectedType() { |
| return null; |
| } |
| } |