Refactory: removed unnecessary local variables and imports.
[phpeclipse.git] / net.sourceforge.phpeclipse / src / net / sourceforge / phpdt / internal / compiler / ast / WhileStatement.java
index 20377b0..ec7dd3e 100644 (file)
@@ -1,28 +1,36 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials 
- * are made available under the terms of the Common Public License v0.5 
+ * 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-v05.html
+ * http://www.eclipse.org/legal/cpl-v10.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.*;
+import net.sourceforge.phpdt.internal.compiler.ASTVisitor;
+import net.sourceforge.phpdt.internal.compiler.codegen.Label;
+import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
+import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
+import net.sourceforge.phpdt.internal.compiler.flow.LoopingFlowContext;
+import net.sourceforge.phpdt.internal.compiler.impl.Constant;
+import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
+import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
 
 public class WhileStatement extends Statement {
-       
+
        public Expression condition;
+
        public Statement action;
+
        private Label breakLabel, continueLabel;
+
        int preCondInitStateIndex = -1;
+
        int condIfTrueInitStateIndex = -1;
+
        int mergedInitStateIndex = -1;
 
        public WhileStatement(Expression condition, Statement action, int s, int e) {
@@ -33,177 +41,216 @@ public class WhileStatement extends Statement {
                sourceEnd = e;
        }
 
-       public FlowInfo analyseCode(
-               BlockScope currentScope,
-               FlowContext flowContext,
-               FlowInfo flowInfo) {
+       public FlowInfo analyseCode(BlockScope currentScope,
+                       FlowContext flowContext, FlowInfo flowInfo) {
 
                breakLabel = new Label();
                continueLabel = new Label();
 
-               preCondInitStateIndex =
-                       currentScope.methodScope().recordInitializationStates(flowInfo);
+               Constant cst = this.condition.constant;
+//             boolean isConditionTrue = cst != NotAConstant
+//                             && cst.booleanValue() == true;
+               boolean isConditionFalse = cst != NotAConstant
+                               && cst.booleanValue() == false;
+
+               cst = this.condition.optimizedBooleanConstant();
+               boolean isConditionOptimizedTrue = cst != NotAConstant
+                               && cst.booleanValue() == true;
+               boolean isConditionOptimizedFalse = cst != NotAConstant
+                               && cst.booleanValue() == false;
+
+               preCondInitStateIndex = currentScope.methodScope()
+                               .recordInitializationStates(flowInfo);
                LoopingFlowContext condLoopContext;
-               FlowInfo postCondInfo =
-                       condition.analyseCode(
-                               currentScope,
-                               (condLoopContext =
-                                       new LoopingFlowContext(flowContext, this, null, null, currentScope)),
-                               flowInfo);
+               FlowInfo postCondInfo = this.condition.analyseCode(currentScope,
+                               (condLoopContext = new LoopingFlowContext(flowContext, this,
+                                               null, null, currentScope)), flowInfo);
 
                LoopingFlowContext loopingContext;
-               if ((action == null) || action.isEmptyBlock()) {
-                       condLoopContext.complainOnFinalAssignmentsInLoop(currentScope, postCondInfo);
-                       if ((condition.constant != NotAConstant)
-                               && (condition.constant.booleanValue() == true)) {
-                               return FlowInfo.DeadEnd;
-                       } else {
-                               FlowInfo mergedInfo = postCondInfo.initsWhenFalse().unconditionalInits();
-                               mergedInitStateIndex =
-                                       currentScope.methodScope().recordInitializationStates(mergedInfo);
-                               return mergedInfo;
-                       }
+               FlowInfo actionInfo;
+               // if (action == null
+               // || (action.isEmptyBlock() &&
+               // currentScope.environment().options.complianceLevel <=
+               // CompilerOptions.JDK1_3)) {
+               // condLoopContext.complainOnFinalAssignmentsInLoop(currentScope,
+               // postCondInfo);
+               // if (isConditionTrue) {
+               // return FlowInfo.DEAD_END;
+               // } else {
+               // FlowInfo mergedInfo =
+               // postCondInfo.initsWhenFalse().unconditionalInits();
+               // if (isConditionOptimizedTrue){
+               // mergedInfo.setReachMode(FlowInfo.UNREACHABLE);
+               // }
+               // mergedInitStateIndex =
+               // currentScope.methodScope().recordInitializationStates(mergedInfo);
+               // return mergedInfo;
+               // }
+               // } else {
+               // in case the condition was inlined to false, record the fact that
+               // there is no way to reach any
+               // statement inside the looping action
+               loopingContext = new LoopingFlowContext(flowContext, this, breakLabel,
+                               continueLabel, currentScope);
+               if (isConditionFalse) {
+                       actionInfo = FlowInfo.DEAD_END;
                } else {
-                       // in case the condition was inlined to false, record the fact that there is no way to reach any 
-                       // statement inside the looping action
-                       loopingContext =
-                               new LoopingFlowContext(
-                                       flowContext,
-                                       this,
-                                       breakLabel,
-                                       continueLabel,
-                                       currentScope);
-                       FlowInfo actionInfo =
-                               ((condition.constant != Constant.NotAConstant)
-                                       && (condition.constant.booleanValue() == false))
-                                       ? FlowInfo.DeadEnd
-                                       : postCondInfo.initsWhenTrue().copy();
-
-                       // for computing local var attributes
-                       condIfTrueInitStateIndex =
-                               currentScope.methodScope().recordInitializationStates(
-                                       postCondInfo.initsWhenTrue());
-
-                       if (!actionInfo.complainIfUnreachable(action, currentScope)) {
-                               actionInfo = action.analyseCode(currentScope, loopingContext, actionInfo);
+                       actionInfo = postCondInfo.initsWhenTrue().copy();
+                       if (isConditionOptimizedFalse) {
+                               actionInfo.setReachMode(FlowInfo.UNREACHABLE);
                        }
+               }
 
-                       // code generation can be optimized when no need to continue in the loop
-                       if (((actionInfo == FlowInfo.DeadEnd) || actionInfo.isFakeReachable())
-                               && ((loopingContext.initsOnContinue == FlowInfo.DeadEnd)
-                                       || loopingContext.initsOnContinue.isFakeReachable())) {
-                               continueLabel = null;
-                       } else {
-                               condLoopContext.complainOnFinalAssignmentsInLoop(currentScope, postCondInfo);
-                               loopingContext.complainOnFinalAssignmentsInLoop(currentScope, actionInfo);
-                       }
+               // for computing local var attributes
+               condIfTrueInitStateIndex = currentScope.methodScope()
+                               .recordInitializationStates(postCondInfo.initsWhenTrue());
+
+               if (!actionInfo.complainIfUnreachable(action, currentScope, false)) {
+                       actionInfo = action.analyseCode(currentScope, loopingContext,
+                                       actionInfo);
                }
 
+               // code generation can be optimized when no need to continue in the loop
+               if (!actionInfo.isReachable()
+                               && !loopingContext.initsOnContinue.isReachable()) {
+                       continueLabel = null;
+               } else {
+                       // TODO: (philippe) should simplify in one Loop context
+                       condLoopContext.complainOnFinalAssignmentsInLoop(currentScope,
+                                       postCondInfo);
+                       loopingContext.complainOnFinalAssignmentsInLoop(currentScope,
+                                       actionInfo);
+               }
+               // }
+
                // infinite loop
                FlowInfo mergedInfo;
-               if ((condition.constant != Constant.NotAConstant)
-                       && (condition.constant.booleanValue() == true)) {
-                       mergedInitStateIndex =
-                               currentScope.methodScope().recordInitializationStates(
-                                       mergedInfo = loopingContext.initsOnBreak);
+               if (isConditionOptimizedTrue) {
+                       mergedInitStateIndex = currentScope.methodScope()
+                                       .recordInitializationStates(
+                                                       mergedInfo = loopingContext.initsOnBreak);
                        return mergedInfo;
                }
 
                // end of loop: either condition false or break
-               mergedInfo =
-                       postCondInfo.initsWhenFalse().unconditionalInits().mergedWith(
-                               loopingContext.initsOnBreak);
-               mergedInitStateIndex =
-                       currentScope.methodScope().recordInitializationStates(mergedInfo);
+               mergedInfo = postCondInfo.initsWhenFalse().unconditionalInits()
+                               .mergedWith(loopingContext.initsOnBreak);
+               if (isConditionOptimizedTrue && continueLabel == null) {
+                       mergedInfo.setReachMode(FlowInfo.UNREACHABLE);
+               }
+               mergedInitStateIndex = currentScope.methodScope()
+                               .recordInitializationStates(mergedInfo);
                return mergedInfo;
        }
 
        /**
         * While code generation
-        *
-        * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
-        * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
+        * 
+        * @param currentScope
+        *            net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
+        * @param codeStream
+        *            net.sourceforge.phpdt.internal.compiler.codegen.CodeStream
         */
-       public void generateCode(BlockScope currentScope, CodeStream codeStream) {
-
-               if ((bits & IsReachableMASK) == 0) {
-                       return;
-               }
-               int pc = codeStream.position;
-               breakLabel.codeStream = codeStream;
-
-               // generate condition
-               if (continueLabel == null) {
-                       // no need to reverse condition
-                       if (condition.constant == NotAConstant) {
-                               condition.generateOptimizedBoolean(
-                                       currentScope,
-                                       codeStream,
-                                       null,
-                                       breakLabel,
-                                       true);
-                       }
-               } else {
-                       continueLabel.codeStream = codeStream;
-                       if (!(((condition.constant != NotAConstant)
-                               && (condition.constant.booleanValue() == true))
-                               || (action == null)
-                               || action.isEmptyBlock())) {
-                               int jumpPC = codeStream.position;
-                               codeStream.goto_(continueLabel);
-                               codeStream.recordPositionsFrom(jumpPC, condition.sourceStart);
-                       }
-               }
-               // generate the action
-               Label actionLabel;
-               (actionLabel = new Label(codeStream)).place();
-               if (action != null) {
-                       // Required to fix 1PR0XVS: LFRE:WINNT - Compiler: variable table for method appears incorrect
-                       if (condIfTrueInitStateIndex != -1) {
-                               // insert all locals initialized inside the condition into the action generated prior to the condition
-                               codeStream.addDefinitelyAssignedVariables(
-                                       currentScope,
-                                       condIfTrueInitStateIndex);
-                       }
-                       action.generateCode(currentScope, codeStream);
-                       // May loose some local variable initializations : affecting the local variable attributes
-                       if (preCondInitStateIndex != -1) {
-                               codeStream.removeNotDefinitelyAssignedVariables(
-                                       currentScope,
-                                       preCondInitStateIndex);
-                       }
-
-               }
-               // output condition and branch back to the beginning of the repeated action
-               if (continueLabel != null) {
-                       continueLabel.place();
-                       condition.generateOptimizedBoolean(
-                               currentScope,
-                               codeStream,
-                               actionLabel,
-                               null,
-                               true);
+       // public void generateCode(BlockScope currentScope, CodeStream codeStream)
+       // {
+       //
+       // if ((bits & IsReachableMASK) == 0) {
+       // return;
+       // }
+       // int pc = codeStream.position;
+       // breakLabel.codeStream = codeStream;
+       //
+       // // generate condition
+       // if (continueLabel == null) {
+       // // no need to reverse condition
+       // if (condition.constant == NotAConstant) {
+       // condition.generateOptimizedBoolean(
+       // currentScope,
+       // codeStream,
+       // null,
+       // breakLabel,
+       // true);
+       // }
+       // } else {
+       // continueLabel.codeStream = codeStream;
+       // if (!(((condition.constant != NotAConstant)
+       // && (condition.constant.booleanValue() == true))
+       // || (action == null)
+       // || action.isEmptyBlock())) {
+       // int jumpPC = codeStream.position;
+       // codeStream.goto_(continueLabel);
+       // codeStream.recordPositionsFrom(jumpPC, condition.sourceStart);
+       // }
+       // }
+       // // generate the action
+       // Label actionLabel;
+       // (actionLabel = new Label(codeStream)).place();
+       // if (action != null) {
+       // // Required to fix 1PR0XVS: LFRE:WINNT - Compiler: variable table for
+       // method appears incorrect
+       // if (condIfTrueInitStateIndex != -1) {
+       // // insert all locals initialized inside the condition into the action
+       // generated prior to the condition
+       // codeStream.addDefinitelyAssignedVariables(
+       // currentScope,
+       // condIfTrueInitStateIndex);
+       // }
+       // action.generateCode(currentScope, codeStream);
+       // // May loose some local variable initializations : affecting the local
+       // variable attributes
+       // if (preCondInitStateIndex != -1) {
+       // codeStream.removeNotDefinitelyAssignedVariables(
+       // currentScope,
+       // preCondInitStateIndex);
+       // }
+       //
+       // }
+       // // output condition and branch back to the beginning of the repeated
+       // action
+       // if (continueLabel != null) {
+       // continueLabel.place();
+       // condition.generateOptimizedBoolean(
+       // currentScope,
+       // codeStream,
+       // actionLabel,
+       // null,
+       // true);
+       // }
+       // breakLabel.place();
+       //
+       // // May loose some local variable initializations : affecting the local
+       // variable attributes
+       // if (mergedInitStateIndex != -1) {
+       // codeStream.removeNotDefinitelyAssignedVariables(
+       // currentScope,
+       // mergedInitStateIndex);
+       // }
+       // codeStream.recordPositionsFrom(pc, this.sourceStart);
+       // }
+       public void resetStateForCodeGeneration() {
+               if (this.breakLabel != null) {
+                       this.breakLabel.resetStateForCodeGeneration();
                }
-               breakLabel.place();
-
-               // May loose some local variable initializations : affecting the local variable attributes
-               if (mergedInitStateIndex != -1) {
-                       codeStream.removeNotDefinitelyAssignedVariables(
-                               currentScope,
-                               mergedInitStateIndex);
+               if (this.continueLabel != null) {
+                       this.continueLabel.resetStateForCodeGeneration();
                }
-               codeStream.recordPositionsFrom(pc, this.sourceStart);
        }
 
-       public void resetStateForCodeGeneration() {
+       public StringBuffer printStatement(int tab, StringBuffer output) {
 
-               this.breakLabel.resetStateForCodeGeneration();
-               this.continueLabel.resetStateForCodeGeneration();
+               printIndent(tab, output).append("while ("); //$NON-NLS-1$
+               condition.printExpression(0, output).append(')');
+               if (action == null)
+                       output.append(';');
+               else
+                       action.printStatement(tab + 1, output);
+               return output;
        }
 
        public void resolve(BlockScope scope) {
 
-               TypeBinding type = condition.resolveTypeExpecting(scope, BooleanBinding);
+               TypeBinding type = condition
+                               .resolveTypeExpecting(scope, BooleanBinding);
                condition.implicitWidening(type, type);
                if (action != null)
                        action.resolve(scope);
@@ -212,7 +259,7 @@ public class WhileStatement extends Statement {
        public String toString(int tab) {
 
                String s = tabString(tab);
-               s = s + "while (" + condition.toStringExpression() + ")";       //$NON-NLS-1$ //$NON-NLS-2$
+               s = s + "while (" + condition.toStringExpression() + ")"; //$NON-NLS-1$ //$NON-NLS-2$
                if (action == null)
                        s = s + " {} ;"; //$NON-NLS-1$ 
                else if (action instanceof Block)
@@ -222,9 +269,7 @@ public class WhileStatement extends Statement {
                return s;
        }
 
-       public void traverse(
-               IAbstractSyntaxTreeVisitor visitor,
-               BlockScope blockScope) {
+       public void traverse(ASTVisitor visitor, BlockScope blockScope) {
 
                if (visitor.visit(this, blockScope)) {
                        condition.traverse(visitor, blockScope);
@@ -233,4 +278,4 @@ public class WhileStatement extends Statement {
                }
                visitor.endVisit(this, blockScope);
        }
-}
\ No newline at end of file
+}