--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v0.5
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v05.html
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ ******************************************************************************/
+package net.sourceforge.phpdt.internal.compiler.ast;
+
+import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
+import net.sourceforge.phpdt.internal.compiler.impl.*;
+import net.sourceforge.phpdt.internal.compiler.codegen.*;
+import net.sourceforge.phpdt.internal.compiler.flow.*;
+import net.sourceforge.phpdt.internal.compiler.lookup.*;
+
+//dedicated treatment for the &&
+public class AND_AND_Expression extends BinaryExpression {
+
+ int rightInitStateIndex = -1;
+ int mergedInitStateIndex = -1;
+
+ public AND_AND_Expression(Expression left, Expression right, int operator) {
+ super(left, right, operator);
+ }
+
+ public FlowInfo analyseCode(
+ BlockScope currentScope,
+ FlowContext flowContext,
+ FlowInfo flowInfo) {
+
+ Constant opConstant = left.conditionalConstant();
+ if (opConstant != NotAConstant) {
+ if (opConstant.booleanValue() == true) {
+ // TRUE && anything
+ // need to be careful of scenario:
+ // (x && y) && !z, if passing the left info to the right, it would be swapped by the !
+ FlowInfo mergedInfo = left.analyseCode(currentScope, flowContext, flowInfo).unconditionalInits();
+ mergedInfo = right.analyseCode(currentScope, flowContext, mergedInfo);
+ mergedInitStateIndex =
+ currentScope.methodScope().recordInitializationStates(mergedInfo);
+ return mergedInfo;
+ }
+ }
+ FlowInfo leftInfo = left.analyseCode(currentScope, flowContext, flowInfo);
+ // need to be careful of scenario:
+ // (x && y) && !z, if passing the left info to the right, it would be swapped by the !
+ FlowInfo rightInfo = leftInfo.initsWhenTrue().unconditionalInits().copy();
+ if (opConstant != NotAConstant && opConstant.booleanValue() == false) rightInfo.markAsFakeReachable(true);
+
+ rightInitStateIndex =
+ currentScope.methodScope().recordInitializationStates(rightInfo);
+ rightInfo = right.analyseCode(currentScope, flowContext, rightInfo);
+ FlowInfo mergedInfo =
+ FlowInfo.conditional(
+ rightInfo.initsWhenTrue().copy(),
+ leftInfo.initsWhenFalse().copy().unconditionalInits().mergedWith(
+ rightInfo.initsWhenFalse().copy().unconditionalInits()));
+ mergedInitStateIndex =
+ currentScope.methodScope().recordInitializationStates(mergedInfo);
+ return mergedInfo;
+ }
+
+ /**
+ * Code generation for a binary operation
+ */
+ public void generateCode(
+ BlockScope currentScope,
+ CodeStream codeStream,
+ boolean valueRequired) {
+
+ int pc = codeStream.position;
+ Label falseLabel, endLabel;
+ if (constant != Constant.NotAConstant) {
+ // inlined value
+ if (valueRequired)
+ codeStream.generateConstant(constant, implicitConversion);
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ return;
+ }
+ bits |= OnlyValueRequiredMASK;
+ generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ null,
+ (falseLabel = new Label(codeStream)),
+ valueRequired);
+ /* improving code gen for such a case: boolean b = i < 0 && false
+ * since the label has never been used, we have the inlined value on the stack. */
+ if (falseLabel.hasForwardReferences()) {
+ if (valueRequired) {
+ codeStream.iconst_1();
+ if ((bits & ValueForReturnMASK) != 0) {
+ codeStream.ireturn();
+ falseLabel.place();
+ codeStream.iconst_0();
+ } else {
+ codeStream.goto_(endLabel = new Label(codeStream));
+ codeStream.decrStackSize(1);
+ falseLabel.place();
+ codeStream.iconst_0();
+ endLabel.place();
+ }
+ } else {
+ falseLabel.place();
+ }
+ }
+ if (valueRequired) {
+ codeStream.generateImplicitConversion(implicitConversion);
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ }
+
+ /**
+ * Boolean operator code generation
+ * Optimized operations are: &&
+ */
+ public void generateOptimizedBoolean(
+ BlockScope currentScope,
+ CodeStream codeStream,
+ Label trueLabel,
+ Label falseLabel,
+ boolean valueRequired) {
+ if ((constant != Constant.NotAConstant) && (constant.typeID() == T_boolean)) {
+ super.generateOptimizedBoolean(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
+ return;
+ }
+ int pc = codeStream.position;
+ Constant condConst;
+ if ((condConst = left.conditionalConstant()) != NotAConstant) {
+ if (condConst.booleanValue() == true) {
+ // <something equivalent to true> && x
+ left.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ trueLabel,
+ falseLabel,
+ false);
+ if (rightInitStateIndex != -1) {
+ codeStream.addDefinitelyAssignedVariables(currentScope, rightInitStateIndex);
+ }
+ if ((bits & OnlyValueRequiredMASK) != 0) {
+ right.generateCode(currentScope, codeStream, valueRequired);
+ } else {
+ right.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ trueLabel,
+ falseLabel,
+ valueRequired);
+ }
+ } else {
+ // <something equivalent to false> && x
+ left.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ trueLabel,
+ falseLabel,
+ false);
+ if (valueRequired) {
+ if ((bits & OnlyValueRequiredMASK) != 0) {
+ codeStream.iconst_0();
+ } else {
+ if (falseLabel != null) {
+ // implicit falling through the TRUE case
+ codeStream.goto_(falseLabel);
+ }
+ }
+ }
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ if (mergedInitStateIndex != -1) {
+ codeStream.removeNotDefinitelyAssignedVariables(
+ currentScope,
+ mergedInitStateIndex);
+ }
+ return;
+ }
+ if ((condConst = right.conditionalConstant()) != NotAConstant) {
+ if (condConst.booleanValue() == true) {
+ // x && <something equivalent to true>
+ if ((bits & OnlyValueRequiredMASK) != 0) {
+ left.generateCode(currentScope, codeStream, valueRequired);
+ } else {
+ left.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ trueLabel,
+ falseLabel,
+ valueRequired);
+ }
+ if (rightInitStateIndex != -1) {
+ codeStream.addDefinitelyAssignedVariables(currentScope, rightInitStateIndex);
+ }
+ right.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ trueLabel,
+ falseLabel,
+ false);
+ } else {
+ // x && <something equivalent to false>
+ left.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ trueLabel,
+ falseLabel,
+ false);
+ if (rightInitStateIndex != -1) {
+ codeStream.addDefinitelyAssignedVariables(currentScope, rightInitStateIndex);
+ }
+ right.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ trueLabel,
+ falseLabel,
+ false);
+ if (valueRequired) {
+ if ((bits & OnlyValueRequiredMASK) != 0) {
+ codeStream.iconst_0();
+ } else {
+ if (falseLabel != null) {
+ // implicit falling through the TRUE case
+ codeStream.goto_(falseLabel);
+ }
+ }
+ }
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ if (mergedInitStateIndex != -1) {
+ codeStream.removeNotDefinitelyAssignedVariables(
+ currentScope,
+ mergedInitStateIndex);
+ }
+ return;
+ }
+ // default case
+ if (falseLabel == null) {
+ if (trueLabel != null) {
+ // implicit falling through the FALSE case
+ Label internalFalseLabel = new Label(codeStream);
+ left.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ null,
+ internalFalseLabel,
+ true);
+ if (rightInitStateIndex != -1) {
+ codeStream.addDefinitelyAssignedVariables(currentScope, rightInitStateIndex);
+ }
+ right.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ trueLabel,
+ null,
+ valueRequired);
+ internalFalseLabel.place();
+ }
+ } else {
+ // implicit falling through the TRUE case
+ if (trueLabel == null) {
+ left.generateOptimizedBoolean(currentScope, codeStream, null, falseLabel, true);
+ if (rightInitStateIndex != -1) {
+ codeStream.addDefinitelyAssignedVariables(currentScope, rightInitStateIndex);
+ }
+ right.generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ null,
+ falseLabel,
+ valueRequired);
+ } else {
+ // no implicit fall through TRUE/FALSE --> should never occur
+ }
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ if (mergedInitStateIndex != -1) {
+ codeStream.removeNotDefinitelyAssignedVariables(
+ currentScope,
+ mergedInitStateIndex);
+ }
+ }
+
+ public boolean isCompactableOperation() {
+ return false;
+ }
+
+ public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope scope) {
+ if (visitor.visit(this, scope)) {
+ left.traverse(visitor, scope);
+ right.traverse(visitor, scope);
+ }
+ visitor.endVisit(this, scope);
+ }
+}
\ No newline at end of file
git://git.phpeclipse.com / phpeclipse.git / blobdiff