--- /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