removed Makefile; lifted repo/org.ibex.tool/src/ to src/

[org.ibex.tool.git] / src / org / eclipse / jdt / internal / compiler / flow / FlowInfo.java

diff --git a/src/org/eclipse/jdt/internal/compiler/flow/FlowInfo.java b/src/org/eclipse/jdt/internal/compiler/flow/FlowInfo.java
new file mode 100644 (file)
index 0000000..1736a5c
--- /dev/null
+++ b/src/org/eclipse/jdt/internal/compiler/flow/FlowInfo.java
@@ -0,0 +1,144 @@
+/*******************************************************************************
+ * 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.flow;
+
+import org.eclipse.jdt.internal.compiler.lookup.FieldBinding;
+import org.eclipse.jdt.internal.compiler.lookup.LocalVariableBinding;
+
+public abstract class FlowInfo {
+
+       public final static int REACHABLE = 0;
+       public final static int UNREACHABLE = 1; 
+       
+       public static final UnconditionalFlowInfo DEAD_END; // Represents a dead branch status of initialization
+       static {
+               DEAD_END = new UnconditionalFlowInfo();
+               DEAD_END.reachMode = UNREACHABLE;
+       }
+       abstract public FlowInfo addInitializationsFrom(FlowInfo otherInits);
+
+       abstract public FlowInfo addPotentialInitializationsFrom(FlowInfo otherInits);
+
+       public FlowInfo asNegatedCondition() {
+
+               return this;
+       }
+
+       public static FlowInfo conditional(FlowInfo initsWhenTrue, FlowInfo initsWhenFalse){
+
+               // if (initsWhenTrue.equals(initsWhenFalse)) return initsWhenTrue; -- could optimize if #equals is defined
+               return new ConditionalFlowInfo(initsWhenTrue, initsWhenFalse);
+       }
+
+       abstract public FlowInfo copy();
+
+       public static UnconditionalFlowInfo initial(int maxFieldCount) {
+               UnconditionalFlowInfo info = new UnconditionalFlowInfo();
+               info.maxFieldCount = maxFieldCount;
+               return info;
+       }
+
+       abstract public FlowInfo initsWhenFalse();
+
+       abstract public FlowInfo initsWhenTrue();
+
+       /**
+        * Check status of definite assignment for a field.
+        */
+        abstract public boolean isDefinitelyAssigned(FieldBinding field);   
+
+       /**
+        * Check status of definite assignment for a local.
+        */
+       public abstract boolean isDefinitelyAssigned(LocalVariableBinding local);
+
+       //abstract public int reachMode(); 
+
+       /**
+        * Check status of potential assignment for a field.
+        */
+        abstract public boolean isPotentiallyAssigned(FieldBinding field);   
+
+       /**
+        * Check status of potential assignment for a local variable.
+        */
+
+        abstract public boolean isPotentiallyAssigned(LocalVariableBinding field);   
+
+       abstract public boolean isReachable();
+       
+       /**
+        * Record a field got definitely assigned.
+        */
+       abstract public void markAsDefinitelyAssigned(FieldBinding field);
+
+       /**
+        * Record a local got definitely assigned.
+        */
+       abstract public void markAsDefinitelyAssigned(LocalVariableBinding local);
+
+       /**
+        * Clear the initialization info for a field
+        */
+       abstract public void markAsDefinitelyNotAssigned(FieldBinding field);
+
+       /**
+        * Clear the initialization info for a local variable
+        */
+       abstract public void markAsDefinitelyNotAssigned(LocalVariableBinding local);
+
+       /**
+        * Merge branches using optimized boolean conditions
+        */
+       public static FlowInfo mergedOptimizedBranches(FlowInfo initsWhenTrue, boolean isOptimizedTrue, FlowInfo initsWhenFalse, boolean isOptimizedFalse, boolean allowFakeDeadBranch) {
+               FlowInfo mergedInfo;
+               if (isOptimizedTrue){
+                       if (initsWhenTrue == FlowInfo.DEAD_END && allowFakeDeadBranch) {
+                               mergedInfo = initsWhenFalse.setReachMode(FlowInfo.UNREACHABLE);
+                       } else {
+                               mergedInfo = initsWhenTrue.addPotentialInitializationsFrom(initsWhenFalse);
+                       }
+
+               } else if (isOptimizedFalse) {
+                       if (initsWhenFalse == FlowInfo.DEAD_END && allowFakeDeadBranch) {
+                               mergedInfo = initsWhenTrue.setReachMode(FlowInfo.UNREACHABLE);
+                       } else {
+                               mergedInfo = initsWhenFalse.addPotentialInitializationsFrom(initsWhenTrue);
+                       }
+
+               } else {
+                       mergedInfo = initsWhenTrue.unconditionalInits().mergedWith(initsWhenFalse.unconditionalInits());
+               }
+               return mergedInfo;
+       }
+       
+       abstract public int reachMode();
+
+       abstract public FlowInfo setReachMode(int reachMode);
+
+       /**
+        * Returns the receiver updated in the following way: <ul>
+        * <li> intersection of definitely assigned variables, 
+        * <li> union of potentially assigned variables.
+        * </ul>
+        */
+       abstract public UnconditionalFlowInfo mergedWith(UnconditionalFlowInfo otherInits);
+
+       public String toString(){
+
+               if (this == DEAD_END){
+                       return "FlowInfo.DEAD_END"; //$NON-NLS-1$
+               }
+               return super.toString();
+       }
+
+       abstract public UnconditionalFlowInfo unconditionalInits();
+}