string += implemented

git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@92 379699f6-c40d-0410-875b-85095c16579e

jode/jode/flow/CreateAssignExpression.java

@@ -23,108 +23,147 @@ import jode.*;
 public class CreateAssignExpression implements Transformation{
 
     public boolean transform(FlowBlock flow) {
+        if (!(flow.lastModified instanceof InstructionContainer)
+            || !(flow.lastModified.outer instanceof SequentialBlock)
+            || !(((InstructionContainer)flow.lastModified).getInstruction()
+                 instanceof StoreInstruction)
+            || !(((InstructionContainer)flow.lastModified).getInstruction()
+                 .isVoid()))
+            return false;
+        
         return (createAssignOp(flow) || createAssignExpression(flow));
     }
 
     public boolean createAssignOp(FlowBlock flow) {
-        Expression rightHandSide;
-        StoreInstruction store;
-        BinaryOperator binop;
-        InstructionContainer lastBlock;
-        SequentialBlock opBlock;
-        SequentialBlock sequBlock;
-        boolean isExpression = false;
-        try {
-            InstructionBlock ib;
-            lastBlock = (InstructionContainer) flow.lastModified;
-            store = (StoreInstruction) lastBlock.getInstruction();
-
-            opBlock = (SequentialBlock) lastBlock.outer;
-            if (opBlock.subBlocks[1] != lastBlock)
-                return false;
 
+        /* Situation:
+         *
+         *   (push loadstoreOps)  <- not checked
+         * sequBlock:
+         *   dup
+         * opBlock:
+         *   load(stack) * rightHandSide
+         *   (optional dup_x)
+         *   store(stack)
+         *
+         * We transform it to:
+         *   (push loadstoreOps)
+         *   rightHandSide
+         *   store(stack) *= (stack)
+         *
+         * If the optional dup is present the store*= becomes non void.
+         */
+        InstructionContainer lastBlock
+            = (InstructionContainer) flow.lastModified;
+        SequentialBlock opBlock = (SequentialBlock) lastBlock.outer;
+        StoreInstruction store 
+            = (StoreInstruction) lastBlock.getInstruction();
+
+        boolean isAssignOp = false;
         if (opBlock.subBlocks[0] instanceof SpecialBlock) {
             SpecialBlock dup = (SpecialBlock) opBlock.subBlocks[0];
             if (dup.type != SpecialBlock.DUP
                 || dup.depth != store.getLValueOperandCount()
-                    || dup.count != store.getLValueType().stackSize())
+                || dup.count != store.getLValueType().stackSize()
+                || !(opBlock.outer instanceof SequentialBlock))
                 return false;
-                opBlock = (SequentialBlock) lastBlock.outer;
+            opBlock = (SequentialBlock) opBlock.outer;
-                isExpression = true;
+            isAssignOp = true;
         }
 
-            ib = (InstructionBlock) opBlock.subBlocks[0];
+        if (!(opBlock.subBlocks[0] instanceof InstructionBlock))
-            ComplexExpression binopExpr = 
-                (ComplexExpression) ib.getInstruction();
-            binop = (BinaryOperator) binopExpr.getOperator();
-            if (binop.getOperatorIndex() <  binop.ADD_OP ||
-                binop.getOperatorIndex() >= binop.ASSIGN_OP)
             return false;
 
-            rightHandSide = binopExpr.getSubExpressions()[1];
+        InstructionBlock ib = (InstructionBlock) opBlock.subBlocks[0];
-            if (rightHandSide.isVoid())
-                return false; /* XXX */
         
-            Operator load = (Operator) binopExpr.getSubExpressions()[0];
+        if (!(opBlock.outer instanceof SequentialBlock)
-            if (!store.matches(load))
+            || !(opBlock.outer.getSubBlocks()[0] instanceof SpecialBlock))
             return false;
 
-            sequBlock = (SequentialBlock) opBlock.outer;
+        SequentialBlock sequBlock = (SequentialBlock) opBlock.outer;
-
         SpecialBlock dup = (SpecialBlock) sequBlock.subBlocks[0];
         if (dup.type != SpecialBlock.DUP
             || dup.depth != 0
             || dup.count != store.getLValueOperandCount())
             return false;
-        } catch (ClassCastException ex) {
+
+        if (!(ib.getInstruction() instanceof ComplexExpression))
             return false;
-        } catch (NullPointerException ex) {
+        ComplexExpression expr = (ComplexExpression) ib.getInstruction();
+
+        int opIndex;
+        Expression rightHandSide;
+
+        if (expr.getOperator() instanceof BinaryOperator) {
+            BinaryOperator binop = (BinaryOperator) expr.getOperator();
+            
+            opIndex = binop.getOperatorIndex();
+            
+            if (opIndex <  binop.ADD_OP || opIndex >= binop.ASSIGN_OP
+                || !(expr.getSubExpressions()[0] instanceof Operator)
+                || !store.matches((Operator) expr.getSubExpressions()[0]))
                 return false;
+            
+            rightHandSide = expr.getSubExpressions()[1];
+        } else {
+            Expression simple = expr.simplifyString();
+            rightHandSide = simple;
+            /* Now search for the leftmost operand ... */
+            ComplexExpression last = null;
+            while (simple instanceof ComplexExpression
+                   && simple.getOperator() instanceof StringAddOperator) {
+                last = (ComplexExpression) simple;
+                simple = last.getSubExpressions()[0];
+            }
+
+            /* ... check it ... */
+            if (last == null || !(simple instanceof Operator)
+                || !store.matches((Operator) simple))
+                return false;
+            
+            /* ... and remove it. */
+            if (last.getParent() != null) {
+                ((ComplexExpression)last.getParent()).getSubExpressions()[0] 
+                    = last.getSubExpressions()[1];
+            } else
+                rightHandSide = last.getSubExpressions()[1]; 
+
+            opIndex = Operator.ADD_OP;
         }
-        ((InstructionBlock)opBlock.subBlocks[0])
+        dup.removeBlock();
-            .setInstruction(rightHandSide);
+        ib.setInstruction(rightHandSide);
-        opBlock.moveDefinitions(sequBlock, opBlock);
+        
-        opBlock.replace(sequBlock);
+        store.setOperatorIndex(store.OPASSIGN_OP+opIndex);
-
+
-        store.setOperatorIndex(store.OPASSIGN_OP+binop.getOperatorIndex());
+        if (isAssignOp)
-        store.setLValueType(binop.getType()
+            store.makeNonVoid();
-                            .intersection(store.getLValueType()));
-
-        if (isExpression)
-            lastBlock.setInstruction
-                (new AssignOperator(store.getOperatorIndex(), store));
-        else
-            lastBlock.setInstruction(store);
-        lastBlock.moveDefinitions(opBlock.subBlocks[1], lastBlock);
         lastBlock.replace(opBlock.subBlocks[1]);
         return true;
     }
 
     public boolean createAssignExpression(FlowBlock flow) {
-        StoreInstruction store;
+        /* Situation:
-        InstructionContainer lastBlock;
+         * sequBlock:
-        SequentialBlock sequBlock;
+         *   dup_X(lvalue_count)
-        try {
+         *   store instruction
-            lastBlock = (InstructionContainer) flow.lastModified;
+         */
-            store = (StoreInstruction) lastBlock.getInstruction();
+        InstructionContainer lastBlock
+            = (InstructionContainer) flow.lastModified;
+        SequentialBlock sequBlock = (SequentialBlock) lastBlock.outer;
+        StoreInstruction store = (StoreInstruction) lastBlock.getInstruction();
 
-            sequBlock = (SequentialBlock) lastBlock.outer;
+        if (sequBlock.subBlocks[0] instanceof SpecialBlock) {
 
             SpecialBlock dup = (SpecialBlock) sequBlock.subBlocks[0];
             if (dup.type != SpecialBlock.DUP
                 || dup.depth != store.getLValueOperandCount()
                 || dup.count != store.getLValueType().stackSize())
                 return false;
-        } catch (NullPointerException ex) {
-            return false;
-        } catch (ClassCastException ex) {
-            return false;
-        }
-        lastBlock.setInstruction
-            (new AssignOperator(store.getOperatorIndex(), store));
-        lastBlock.moveDefinitions(sequBlock, lastBlock);
-        lastBlock.replace(sequBlock);
-        return true;
             
+            dup.removeBlock();
+            store.makeNonVoid();
+            return true;
+        }
+        return false;
     }
 }