This will one time mark inlined expression, to allow further handling.

this doesn't even compile yet


git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@184 379699f6-c40d-0410-875b-85095c16579e

jode/jode/flow/MarkInlineExpression.java

@@ -27,15 +27,29 @@ import jode.decompiler.*;
  * The parameters may be stored in locals, before inlining the body of the
  * method.  
  * 
- * This transformation will mark the expression as inlined and 
- * This transformation creates expressions.  It transforms
- * <pre>
- *  Sequ[expr_1, Sequ[expr_2, ..., Sequ[expr_n, op] ...]] 
- * </pre>
- * to
- * <pre>
- *  expr(op, [ expr_1, ..., expr_n ])
- * </pre>
+ * Inlined methods look as follows:
+ * 
+ * local_1 = expr_1
+ * local_2 = expr_2
+ * [PUSH ]expr(local_1,local_2,constants...)
+ *
+ * where local_1 and local_2 aren't used any more.
+ *
+ * If later one finds a reuse of local_x, the inline transformation
+ * must be reverted: If there is no surrounding expression, the locals
+ * are moved to initializers around; otherwise if the locals are used
+ * in the expression or a super expression, they are combined with the
+ * next occurence; otherwise the locals are moved behind the next expression.
+ * This doesn't care for side effects though :-(
+ *
+ * There are many other reasons why a part could look like this; only
+ * if a matching method is found, that does exactly this (or if the
+ * options createInlines is given), we may call this method.  
+ *
+ * As long as inlines are not supported, if the local is never used, it
+ * is simply removed; if the local is used only one time and there are
+ * no side effects to the expression on the right hand side between usage
+ * and initialization, the usage is replaced by the right hand side.
  */
 public class MarkInlineExpression {
 
@@ -52,88 +66,51 @@ public class MarkInlineExpression {
             return false;
 
         ComplexExpression parent = null;
-        Expression inner = ic.getInstruction();
-        while (inner instanceof ComplexExpression) {
-            parent = (ComplexExpression)inner;
-            inner = parent.getSubExpressions()[0];
-        }
-
-        if (!(inner instanceof Operator))
-            return false;
-
-        Operator op = (Operator)inner;
+        Expression expr = ic.getInstruction();
 
         if (!(last.outer instanceof SequentialBlock))
             return false;
         SequentialBlock sequBlock = (SequentialBlock)last.outer;
 
-        /* First check if Expression can be created, but do nothing yet.
-         */
-        Expression lastExpression = null;
-        for (int i = params;;) {
-
-            if (!(sequBlock.subBlocks[0] instanceof InstructionBlock))
-                return false;
-            
-            Expression expr =
-                ((InstructionBlock) sequBlock.subBlocks[0]).getInstruction();
-            
-            
-            if (!expr.isVoid()) {
-                if (--i == 0)
-                    break;
-            } else if (lastExpression == null
-                       || lastExpression.canCombine(expr) <= 0)
-                return false;
-
-            if (expr.getOperandCount() > 0)
-                /* This is a not fully resolved expression in the
-                 * middle, we must not touch it.  */
-                return false;
-
-            lastExpression =  expr;
-            
-            if (!(sequBlock.outer instanceof SequentialBlock))
-                return false;
-            sequBlock = (SequentialBlock) sequBlock.outer;
+	int localCount = 0;
+	while (sequBlock.subBlocks[0] instanceof InstructionBlock) {
+	    InstructionBlock assign = 
+		(InstructionBlock) sequBlock.subBlocks[0];
+	    if (!(assign.getInstruction().getOperator()
+		  instanceof LocalStoreOperator)
+		|| assign.getInstruction().getOperandCount() == 0)
+		break;
+	    
+	    LocalStoreOperator store = (LocalStoreOperator)
+		assign.getInstruction().getOperator();
+	    if (!store.getLocal().onlyUsedInside(expr))
+		break;
+
+	    localCount++;
+
+	    if (!(sequBlock.outer instanceof SequentialBlock))
+		break;
+	    sequBlock = (SequentialBlock)sequBlock.outer;
         }
+	if (localCount == 0)
+	    return false;
 
-        /* Now, do the combination. Everything must succeed now.
-         */
-        Expression[] exprs = new Expression[params];
+	Expression[] stores = new Expression[localCount];
         sequBlock = (SequentialBlock) last.outer;
-        for (int i=params; ;) {
-
-            Expression expr =
-                ((InstructionBlock) sequBlock.subBlocks[0]).getInstruction();
-            
-            if (!expr.isVoid()) {
-                exprs[--i] = expr;
-                if (i == 0)
-                    break;
-            } else
-                exprs[i] = exprs[i].combine(expr);
-            
-            sequBlock = (SequentialBlock)sequBlock.outer;
-        }
-
-        if(Decompiler.isVerbose)
-            Decompiler.err.print('x');
-
-        Expression newExpr;
-        if (params == 1 && op instanceof NopOperator) {
-            exprs[0].setType(op.getType());
-            newExpr = exprs[0];
-        } else
-            newExpr = new ComplexExpression(op, exprs);
-
-        if (parent != null)
-            parent.setSubExpressions(0, newExpr);
-        else
-            ic.setInstruction(newExpr);
-
+        for (int i=0; i<stores; i++) {
+	    stores[i] = ((InstructionBlock)sequBlock.subBlocks[0])
+		.getInstruction();
+	    LocalStoreOperator store = 
+		(LocalStoreOperator) stores[i].getOperator();
+	    if (!store.getLocal().onlyUsedInside(expr))
+	    stores[i].get.markInlinedIn(expr);
+	    sequBlock = (SequentialBlock)sequBlock.outer;
+	}
+
+	expr.markInlineExpression(stores);
         ic.moveDefinitions(sequBlock, last);
         last.replace(sequBlock);
         return true;
     }
 }
+