reworked canCombine, combine.

this is currently *NOT* correct, because it doesn't handle side effects.
but it is really unlikely that real world code can invoke this wrong behaviour


git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@178 379699f6-c40d-0410-875b-85095c16579e

jode/jode/expr/ComplexExpression.java

@@ -72,33 +72,44 @@ public class ComplexExpression extends Expression {
     }
 
     /**
-     * Checks if the given Expression (which should be a StoreInstruction)
+     * Checks if the given Expression (which must be a CombineableOperator)
      * can be combined into this expression.
      * @param e The store expression, must be of type void.
      * @return 1, if it can, 0, if no match was found and -1, if a
      * conflict was found.  You may wish to check for >0.
+     * @exception ClassCastException, if e.getOperator 
+     * is not a CombineableOperator.
      */
     public int canCombine(Expression e) {
-	if (e instanceof ComplexExpression
-            && e.getOperator() instanceof StoreInstruction
-            && ((StoreInstruction) e.getOperator()).matches(operator)) {
-
-            ComplexExpression ce = (ComplexExpression) e;
-            for (int i=0; i < ce.subExpressions.length-1; i++) {
-                if (!ce.subExpressions[i].equals(subExpressions[i]))
-                    return -1;
-            }
-            return 1;
+// 	Decompiler.err.println("Try to combine "+e+" into "+this);
+	if (e.getOperator() instanceof LocalStoreOperator
+	    && e.getOperandCount() == 0) {
+	    // Special case for locals created on inlining methods, which may
+	    // combine everywhere
+	    return containsMatchingLoad(e) ? 1 : 0;
+	}
+
+	if (e instanceof ComplexExpression) {
+	    if (((CombineableOperator) e.getOperator()).matches(operator)) {
+		ComplexExpression ce = (ComplexExpression) e;
+		for (int i=0; i < ce.subExpressions.length-1; i++) {
+		    if (!ce.subExpressions[i].equals(subExpressions[i]))
+			return -1;
+		}
+		return 1;
+	    }
         }
         return subExpressions[0].canCombine(e);
     }
 
     /**
      * Checks if this expression contains a load, that matches the
-     * given Expression (which should be a
+     * given Expression (which must be a
      * StoreInstruction/IIncOperator).
      * @param e The store expression.
      * @return if this expression contains a matching load.
+     * @exception ClassCastException, if e.getOperator 
+     * is not a CombineableOperator.
      */
     public boolean containsMatchingLoad(Expression e) {
 	if (e instanceof ComplexExpression
@@ -127,13 +138,15 @@ public class ComplexExpression extends Expression {
      * canCombine returns the value 1.
      * @param e The store expression.
      * @return The combined expression.
+     * @exception ClassCastException, if e.getOperator 
+     * is not a CombineableOperator.
      */
     public Expression combine(Expression e) {
 
-        StoreInstruction store = (StoreInstruction) e.getOperator();
-        if (store.matches(operator)) {
-            store.makeNonVoid();
-            e.type = store.getType();
+        CombineableOperator op = (CombineableOperator) e.getOperator();
+        if (op.matches(operator)) {
+            op.makeNonVoid();
+            e.type = e.getOperator().getType();
             return e;
         }
         for (int i=0; i < subExpressions.length; i++) {