Swaps are merged into expressions

git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@203 379699f6-c40d-0410-875b-85095c16579e

jode/jode/flow/CreateExpression.java

@@ -40,7 +40,6 @@ public class CreateExpression {
      */
     public static boolean transform(InstructionContainer ic,
                                     StructuredBlock last) {
-
         int params = ic.getInstruction().getOperandCount();
         if (params == 0)
             return false;
@@ -66,6 +65,17 @@ public class CreateExpression {
         Expression lastExpression = null;
         for (int i = params;;) {
 	    
+	    if (i >= 2 && sequBlock.subBlocks[0] instanceof SpecialBlock) {
+		/* Transform (this is for string += under jikes)
+		 *   PUSH arg2
+		 *   PUSH arg1
+		 *   SWAP
+		 */
+		SpecialBlock swap = (SpecialBlock) sequBlock.subBlocks[0];
+		if (swap.type != SpecialBlock.SWAP)
+		    return false;
+		/* XXX check if swapping is possible */
+	    } else {
 		if (!(sequBlock.subBlocks[0] instanceof InstructionBlock))
 		    return false;
 		
@@ -87,7 +97,7 @@ public class CreateExpression {
 		    return false;
 
 		lastExpression =  expr;
-            
+	    }
 	    if (!(sequBlock.outer instanceof SequentialBlock))
 		return false;
             sequBlock = (SequentialBlock) sequBlock.outer;
@@ -97,17 +107,38 @@ public class CreateExpression {
          */
         Expression[] exprs = new Expression[params];
         sequBlock = (SequentialBlock) last.outer;
+	int swapping = 0;
         for (int i=params; ;) {
 
+	    if (sequBlock.subBlocks[0] instanceof SpecialBlock) {
+		// This must be a swap (see above).
+		swapping = 1;
+		
+	    } else {
 		Expression expr =
 		    ((InstructionBlock) sequBlock.subBlocks[0]).getInstruction();
 		
 		if (!expr.isVoid()) {
+		    if (swapping == 1) {
+			// We start swapping:
+			i--;
+			swapping = 2;
+		    } else if (swapping == 2) {
+			// We continue swapping:
+			i += 2;
+			swapping = 3;
+		    } else if (swapping == 3) {
+			// Now we end swapping:
+			i--;
+			swapping = 0;
+		    }
 		    exprs[--i] = expr;
-                if (i == 0)
+		    if (i == 0 && swapping == 0
+			|| i == 1 && swapping == 3)
 			break;
 		} else
 		    exprs[i] = exprs[i].combine(expr);
+	    }
             
             sequBlock = (SequentialBlock)sequBlock.outer;
         }