+++ /dev/null
-/*******************************************************************************
- * Copyright (c) 2000, 2004 IBM Corporation and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Common Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/cpl-v10.html
- *
- * Contributors:
- * IBM Corporation - initial API and implementation
- *******************************************************************************/
-package org.eclipse.jdt.internal.compiler.ast;
-
-import org.eclipse.jdt.internal.compiler.ASTVisitor;
-import org.eclipse.jdt.internal.compiler.impl.*;
-import org.eclipse.jdt.internal.compiler.codegen.*;
-import org.eclipse.jdt.internal.compiler.flow.*;
-import org.eclipse.jdt.internal.compiler.lookup.*;
-
-public class ConditionalExpression extends OperatorExpression {
-
- public Expression condition, valueIfTrue, valueIfFalse;
- public Constant optimizedBooleanConstant;
- public Constant optimizedIfTrueConstant;
- public Constant optimizedIfFalseConstant;
-
- // for local variables table attributes
- int trueInitStateIndex = -1;
- int falseInitStateIndex = -1;
- int mergedInitStateIndex = -1;
-
- public ConditionalExpression(
- Expression condition,
- Expression valueIfTrue,
- Expression valueIfFalse) {
- this.condition = condition;
- this.valueIfTrue = valueIfTrue;
- this.valueIfFalse = valueIfFalse;
- sourceStart = condition.sourceStart;
- sourceEnd = valueIfFalse.sourceEnd;
- }
-
- public FlowInfo analyseCode(
- BlockScope currentScope,
- FlowContext flowContext,
- FlowInfo flowInfo) {
-
- Constant cst = this.condition.optimizedBooleanConstant();
- boolean isConditionOptimizedTrue = cst != NotAConstant && cst.booleanValue() == true;
- boolean isConditionOptimizedFalse = cst != NotAConstant && cst.booleanValue() == false;
-
- int mode = flowInfo.reachMode();
- flowInfo = condition.analyseCode(currentScope, flowContext, flowInfo, cst == NotAConstant);
-
- // process the if-true part
- FlowInfo trueFlowInfo = flowInfo.initsWhenTrue().copy();
- if (isConditionOptimizedFalse) {
- trueFlowInfo.setReachMode(FlowInfo.UNREACHABLE);
- }
- trueInitStateIndex = currentScope.methodScope().recordInitializationStates(trueFlowInfo);
- trueFlowInfo = valueIfTrue.analyseCode(currentScope, flowContext, trueFlowInfo);
-
- // process the if-false part
- FlowInfo falseFlowInfo = flowInfo.initsWhenFalse().copy();
- if (isConditionOptimizedTrue) {
- falseFlowInfo.setReachMode(FlowInfo.UNREACHABLE);
- }
- falseInitStateIndex = currentScope.methodScope().recordInitializationStates(falseFlowInfo);
- falseFlowInfo = valueIfFalse.analyseCode(currentScope, flowContext, falseFlowInfo);
-
- // merge if-true & if-false initializations
- FlowInfo mergedInfo;
- if (isConditionOptimizedTrue){
- mergedInfo = trueFlowInfo.addPotentialInitializationsFrom(falseFlowInfo);
- } else if (isConditionOptimizedFalse) {
- mergedInfo = falseFlowInfo.addPotentialInitializationsFrom(trueFlowInfo);
- } else {
- // if ((t && (v = t)) ? t : t && (v = f)) r = v; -- ok
- cst = this.optimizedIfTrueConstant;
- boolean isValueIfTrueOptimizedTrue = cst != null && cst != NotAConstant && cst.booleanValue() == true;
- boolean isValueIfTrueOptimizedFalse = cst != null && cst != NotAConstant && cst.booleanValue() == false;
-
- cst = this.optimizedIfFalseConstant;
- boolean isValueIfFalseOptimizedTrue = cst != null && cst != NotAConstant && cst.booleanValue() == true;
- boolean isValueIfFalseOptimizedFalse = cst != null && cst != NotAConstant && cst.booleanValue() == false;
-
- UnconditionalFlowInfo trueInfoWhenTrue = trueFlowInfo.initsWhenTrue().copy().unconditionalInits();
- if (isValueIfTrueOptimizedFalse) trueInfoWhenTrue.setReachMode(FlowInfo.UNREACHABLE);
-
- UnconditionalFlowInfo falseInfoWhenTrue = falseFlowInfo.initsWhenTrue().copy().unconditionalInits();
- if (isValueIfFalseOptimizedFalse) falseInfoWhenTrue.setReachMode(FlowInfo.UNREACHABLE);
-
- UnconditionalFlowInfo trueInfoWhenFalse = trueFlowInfo.initsWhenFalse().copy().unconditionalInits();
- if (isValueIfTrueOptimizedTrue) trueInfoWhenFalse.setReachMode(FlowInfo.UNREACHABLE);
-
- UnconditionalFlowInfo falseInfoWhenFalse = falseFlowInfo.initsWhenFalse().copy().unconditionalInits();
- if (isValueIfFalseOptimizedTrue) falseInfoWhenFalse.setReachMode(FlowInfo.UNREACHABLE);
-
- mergedInfo =
- FlowInfo.conditional(
- trueInfoWhenTrue.mergedWith(falseInfoWhenTrue),
- trueInfoWhenFalse.mergedWith(falseInfoWhenFalse));
- }
- mergedInitStateIndex =
- currentScope.methodScope().recordInitializationStates(mergedInfo);
- mergedInfo.setReachMode(mode);
- return mergedInfo;
- }
-
- /**
- * Code generation for the conditional operator ?:
- *
- * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
- * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
- * @param valueRequired boolean
- */
- public void generateCode(
- BlockScope currentScope,
- CodeStream codeStream,
- boolean valueRequired) {
-
- int pc = codeStream.position;
- Label endifLabel, falseLabel;
- if (constant != NotAConstant) {
- if (valueRequired)
- codeStream.generateConstant(constant, implicitConversion);
- codeStream.recordPositionsFrom(pc, this.sourceStart);
- return;
- }
- Constant cst = condition.constant;
- Constant condCst = condition.optimizedBooleanConstant();
- boolean needTruePart =
- !(((cst != NotAConstant) && (cst.booleanValue() == false))
- || ((condCst != NotAConstant) && (condCst.booleanValue() == false)));
- boolean needFalsePart =
- !(((cst != NotAConstant) && (cst.booleanValue() == true))
- || ((condCst != NotAConstant) && (condCst.booleanValue() == true)));
- endifLabel = new Label(codeStream);
-
- // Generate code for the condition
- boolean needConditionValue = (cst == NotAConstant) && (condCst == NotAConstant);
- condition.generateOptimizedBoolean(
- currentScope,
- codeStream,
- null,
- (falseLabel = new Label(codeStream)),
- needConditionValue);
-
- if (trueInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(
- currentScope,
- trueInitStateIndex);
- codeStream.addDefinitelyAssignedVariables(currentScope, trueInitStateIndex);
- }
- // Then code generation
- if (needTruePart) {
- valueIfTrue.generateCode(currentScope, codeStream, valueRequired);
- if (needFalsePart) {
- // Jump over the else part
- int position = codeStream.position;
- codeStream.goto_(endifLabel);
- codeStream.updateLastRecordedEndPC(position);
- // Tune codestream stack size
- if (valueRequired) {
- codeStream.decrStackSize(this.resolvedType == LongBinding || this.resolvedType == DoubleBinding ? 2 : 1);
- }
- }
- }
- if (needFalsePart) {
- falseLabel.place();
- if (falseInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(
- currentScope,
- falseInitStateIndex);
- codeStream.addDefinitelyAssignedVariables(currentScope, falseInitStateIndex);
- }
- valueIfFalse.generateCode(currentScope, codeStream, valueRequired);
- // End of if statement
- endifLabel.place();
- }
- // May loose some local variable initializations : affecting the local variable attributes
- if (mergedInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(
- currentScope,
- mergedInitStateIndex);
- }
- // implicit conversion
- if (valueRequired)
- codeStream.generateImplicitConversion(implicitConversion);
- codeStream.recordPositionsFrom(pc, this.sourceStart);
- }
-
- /**
- * Optimized boolean code generation for the conditional operator ?:
- */
- public void generateOptimizedBoolean(
- BlockScope currentScope,
- CodeStream codeStream,
- Label trueLabel,
- Label falseLabel,
- boolean valueRequired) {
-
- if ((constant != Constant.NotAConstant) && (constant.typeID() == T_boolean) // constant
- || (valueIfTrue.implicitConversion >> 4) != T_boolean) { // non boolean values
- super.generateOptimizedBoolean(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
- return;
- }
- Constant cst = condition.constant;
- Constant condCst = condition.optimizedBooleanConstant();
- boolean needTruePart =
- !(((cst != NotAConstant) && (cst.booleanValue() == false))
- || ((condCst != NotAConstant) && (condCst.booleanValue() == false)));
- boolean needFalsePart =
- !(((cst != NotAConstant) && (cst.booleanValue() == true))
- || ((condCst != NotAConstant) && (condCst.booleanValue() == true)));
-
- Label internalFalseLabel, endifLabel = new Label(codeStream);
-
- // Generate code for the condition
- boolean needConditionValue = (cst == NotAConstant) && (condCst == NotAConstant);
- condition.generateOptimizedBoolean(
- currentScope,
- codeStream,
- null,
- internalFalseLabel = new Label(codeStream),
- needConditionValue);
-
- if (trueInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(
- currentScope,
- trueInitStateIndex);
- codeStream.addDefinitelyAssignedVariables(currentScope, trueInitStateIndex);
- }
- // Then code generation
- if (needTruePart) {
- valueIfTrue.generateOptimizedBoolean(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
-
- if (needFalsePart) {
- // Jump over the else part
- int position = codeStream.position;
- codeStream.goto_(endifLabel);
- codeStream.updateLastRecordedEndPC(position);
- // No need to decrement codestream stack size
- // since valueIfTrue was already consumed by branch bytecode
- }
- }
- if (needFalsePart) {
- internalFalseLabel.place();
- if (falseInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(
- currentScope,
- falseInitStateIndex);
- codeStream.addDefinitelyAssignedVariables(currentScope, falseInitStateIndex);
- }
- valueIfFalse.generateOptimizedBoolean(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
-
- // End of if statement
- endifLabel.place();
- }
- // May loose some local variable initializations : affecting the local variable attributes
- if (mergedInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(
- currentScope,
- mergedInitStateIndex);
- }
- // no implicit conversion for boolean values
- codeStream.updateLastRecordedEndPC(codeStream.position);
- }
-
- public Constant optimizedBooleanConstant() {
-
- return this.optimizedBooleanConstant == null ? this.constant : this.optimizedBooleanConstant;
- }
-
- public StringBuffer printExpressionNoParenthesis(int indent, StringBuffer output) {
-
- condition.printExpression(indent, output).append(" ? "); //$NON-NLS-1$
- valueIfTrue.printExpression(0, output).append(" : "); //$NON-NLS-1$
- return valueIfFalse.printExpression(0, output);
- }
-
- public TypeBinding resolveType(BlockScope scope) {
- // specs p.368
- constant = NotAConstant;
- TypeBinding conditionType = condition.resolveTypeExpecting(scope, BooleanBinding);
-
- if (valueIfTrue instanceof CastExpression) valueIfTrue.bits |= IgnoreNeedForCastCheckMASK; // will check later on
- TypeBinding valueIfTrueType = valueIfTrue.resolveType(scope);
-
- if (valueIfFalse instanceof CastExpression) valueIfFalse.bits |= IgnoreNeedForCastCheckMASK; // will check later on
- TypeBinding valueIfFalseType = valueIfFalse.resolveType(scope);
-
- if (conditionType == null || valueIfTrueType == null || valueIfFalseType == null)
- return null;
-
- // Propagate the constant value from the valueIfTrue and valueIFFalse expression if it is possible
- Constant condConstant, trueConstant, falseConstant;
- if ((condConstant = condition.constant) != NotAConstant
- && (trueConstant = valueIfTrue.constant) != NotAConstant
- && (falseConstant = valueIfFalse.constant) != NotAConstant) {
- // all terms are constant expression so we can propagate the constant
- // from valueIFTrue or valueIfFalse to teh receiver constant
- constant = condConstant.booleanValue() ? trueConstant : falseConstant;
- }
- if (valueIfTrueType == valueIfFalseType) { // harmed the implicit conversion
- valueIfTrue.implicitWidening(valueIfTrueType, valueIfTrueType);
- valueIfFalse.implicitConversion = valueIfTrue.implicitConversion;
- if (valueIfTrueType == BooleanBinding) {
- this.optimizedIfTrueConstant = valueIfTrue.optimizedBooleanConstant();
- this.optimizedIfFalseConstant = valueIfFalse.optimizedBooleanConstant();
- if (this.optimizedIfTrueConstant != NotAConstant
- && this.optimizedIfFalseConstant != NotAConstant
- && this.optimizedIfTrueConstant.booleanValue() == this.optimizedIfFalseConstant.booleanValue()) {
- // a ? true : true / a ? false : false
- this.optimizedBooleanConstant = optimizedIfTrueConstant;
- } else if ((condConstant = condition.optimizedBooleanConstant()) != NotAConstant) { // Propagate the optimized boolean constant if possible
- this.optimizedBooleanConstant = condConstant.booleanValue()
- ? this.optimizedIfTrueConstant
- : this.optimizedIfFalseConstant;
- }
- }
- return this.resolvedType = valueIfTrueType;
- }
- // Determine the return type depending on argument types
- // Numeric types
- if (valueIfTrueType.isNumericType() && valueIfFalseType.isNumericType()) {
- // (Short x Byte) or (Byte x Short)"
- if ((valueIfTrueType == ByteBinding && valueIfFalseType == ShortBinding)
- || (valueIfTrueType == ShortBinding && valueIfFalseType == ByteBinding)) {
- valueIfTrue.implicitWidening(ShortBinding, valueIfTrueType);
- valueIfFalse.implicitWidening(ShortBinding, valueIfFalseType);
- return this.resolvedType = ShortBinding;
- }
- // <Byte|Short|Char> x constant(Int) ---> <Byte|Short|Char> and reciprocally
- if ((valueIfTrueType == ByteBinding || valueIfTrueType == ShortBinding || valueIfTrueType == CharBinding)
- && (valueIfFalseType == IntBinding
- && valueIfFalse.isConstantValueOfTypeAssignableToType(valueIfFalseType, valueIfTrueType))) {
- valueIfTrue.implicitWidening(valueIfTrueType, valueIfTrueType);
- valueIfFalse.implicitWidening(valueIfTrueType, valueIfFalseType);
- return this.resolvedType = valueIfTrueType;
- }
- if ((valueIfFalseType == ByteBinding
- || valueIfFalseType == ShortBinding
- || valueIfFalseType == CharBinding)
- && (valueIfTrueType == IntBinding
- && valueIfTrue.isConstantValueOfTypeAssignableToType(valueIfTrueType, valueIfFalseType))) {
- valueIfTrue.implicitWidening(valueIfFalseType, valueIfTrueType);
- valueIfFalse.implicitWidening(valueIfFalseType, valueIfFalseType);
- return this.resolvedType = valueIfFalseType;
- }
- // Manual binary numeric promotion
- // int
- if (BaseTypeBinding.isNarrowing(valueIfTrueType.id, T_int)
- && BaseTypeBinding.isNarrowing(valueIfFalseType.id, T_int)) {
- valueIfTrue.implicitWidening(IntBinding, valueIfTrueType);
- valueIfFalse.implicitWidening(IntBinding, valueIfFalseType);
- return this.resolvedType = IntBinding;
- }
- // long
- if (BaseTypeBinding.isNarrowing(valueIfTrueType.id, T_long)
- && BaseTypeBinding.isNarrowing(valueIfFalseType.id, T_long)) {
- valueIfTrue.implicitWidening(LongBinding, valueIfTrueType);
- valueIfFalse.implicitWidening(LongBinding, valueIfFalseType);
- return this.resolvedType = LongBinding;
- }
- // float
- if (BaseTypeBinding.isNarrowing(valueIfTrueType.id, T_float)
- && BaseTypeBinding.isNarrowing(valueIfFalseType.id, T_float)) {
- valueIfTrue.implicitWidening(FloatBinding, valueIfTrueType);
- valueIfFalse.implicitWidening(FloatBinding, valueIfFalseType);
- return this.resolvedType = FloatBinding;
- }
- // double
- valueIfTrue.implicitWidening(DoubleBinding, valueIfTrueType);
- valueIfFalse.implicitWidening(DoubleBinding, valueIfFalseType);
- return this.resolvedType = DoubleBinding;
- }
- // Type references (null null is already tested)
- if ((valueIfTrueType.isBaseType() && valueIfTrueType != NullBinding)
- || (valueIfFalseType.isBaseType() && valueIfFalseType != NullBinding)) {
- scope.problemReporter().conditionalArgumentsIncompatibleTypes(
- this,
- valueIfTrueType,
- valueIfFalseType);
- return null;
- }
- if (valueIfFalseType.isCompatibleWith(valueIfTrueType)) {
- valueIfTrue.implicitWidening(valueIfTrueType, valueIfTrueType);
- valueIfFalse.implicitWidening(valueIfTrueType, valueIfFalseType);
- return this.resolvedType = valueIfTrueType;
- }
- if (valueIfTrueType.isCompatibleWith(valueIfFalseType)) {
- valueIfTrue.implicitWidening(valueIfFalseType, valueIfTrueType);
- valueIfFalse.implicitWidening(valueIfFalseType, valueIfFalseType);
- return this.resolvedType = valueIfFalseType;
- }
- scope.problemReporter().conditionalArgumentsIncompatibleTypes(
- this,
- valueIfTrueType,
- valueIfFalseType);
- return null;
- }
-
- public void traverse(ASTVisitor visitor, BlockScope scope) {
- if (visitor.visit(this, scope)) {
- condition.traverse(visitor, scope);
- valueIfTrue.traverse(visitor, scope);
- valueIfFalse.traverse(visitor, scope);
- }
- visitor.endVisit(this, scope);
- }
-}
projects / org.ibex.tool.git / blobdiff