Labelled Blocks

git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@1416 379699f6-c40d-0410-875b-85095c16579e

jode/src/net/sf/jode/flow/FlowBlock.java

@@ -226,7 +226,13 @@ public class FlowBlock {
         if (jumps == null)
             return null;
         Jump remainingJumps = null;
+        
+        /* find the smallest block containing all jumps */
         lastModified = jumps.prev;
+        for (Jump jump = jumps.next; jump != null; jump = jump.next) {
+            while (!lastModified.contains(jump.prev))
+        	lastModified = lastModified.outer;
+        }
         StructuredBlock b = lastModified.outer;
         while (b != null) {
             if (b.outer instanceof TryBlock
@@ -282,7 +288,7 @@ public class FlowBlock {
                 ConditionalBlock cb = (ConditionalBlock) prev.outer;
                 Expression instr = cb.getInstruction();
 
-		/* This is a jump inside an ConditionalBlock. 
+		/* This is a jump inside a ConditionalBlock. 
 		 *
 		 * cb    is the conditional block, 
 		 * prev  the empty block containing the jump
@@ -290,7 +296,7 @@ public class FlowBlock {
 
                 if (cb.jump != null) {
                     /* This can only happen if cb also jumps to succ.
-                     * This is a weired "if (cond) empty"-block.  We
+                     * This is a weird "if (cond) empty"-block.  We
                      * transform it by hand.  
                      */		    
                     prev.removeJump();
@@ -335,6 +341,8 @@ public class FlowBlock {
 
                         loopBlock.setCondition(instr.negate());
                         loopBlock.moveDefinitions(cb, null);
+                        if (loopBlock.contains(lastModified))
+                            lastModified = loopBlock;
                         cb.removeBlock();
                         continue;
                     }
@@ -371,6 +379,8 @@ public class FlowBlock {
                             loopBlock.setType(LoopBlock.DOWHILE);
                             loopBlock.setCondition(instr.negate());
                             loopBlock.moveDefinitions(cb, null);
+                            if (loopBlock.contains(lastModified))
+                                lastModified = loopBlock;
                             cb.removeBlock();                            
                             continue;
                         }
@@ -590,11 +600,11 @@ public class FlowBlock {
 
     /**
      * Resolve remaining jumps to the successor by generating break
-     * instructions.  As last resort generate a do while(false) block.
+     * instructions.  As last resort generate a labelled block.
      * @param jumps The jump list that need to be resolved.
      */
     void resolveRemaining(Jump jumps) {
-        LoopBlock doWhileFalse = null;
+        LabelledBlock labelledBlock = null;
         StructuredBlock outerMost = lastModified;
         boolean removeLast = false;
         for (; jumps != null; jumps = jumps.next) {
@@ -622,19 +632,18 @@ public class FlowBlock {
             prevBlock.removeJump();
             
             if (breakToBlock == null) {
-                /* Nothing else helped, so put a do/while(0)
+                /* Nothing else helped, so put a labelled
                  * block around outerMost and break to that
                  * block.
                  */
-                if (doWhileFalse == null) {
+                if (labelledBlock == null) {
-                    doWhileFalse = new LoopBlock(LoopBlock.DOWHILE, 
+                    labelledBlock = new LabelledBlock();
-                                                 LoopBlock.FALSE);
                 }
                 /* Adapt outermost, so that it contains the break. */
                 while (!outerMost.contains(prevBlock))
                     outerMost = outerMost.outer;
                 prevBlock.appendBlock
-                    (new BreakBlock(doWhileFalse, breaklevel > 0));
+                    (new BreakBlock(labelledBlock, true));
             } else
                 prevBlock.appendBlock
                     (new BreakBlock(breakToBlock, breaklevel > 1));
@@ -643,10 +652,10 @@ public class FlowBlock {
         if (removeLast)
             lastModified.removeJump();
 
-        if (doWhileFalse != null) {
+        if (labelledBlock != null) {
-            doWhileFalse.replace(outerMost);
+            labelledBlock.replace(outerMost);
-            doWhileFalse.setBody(outerMost);
+            labelledBlock.setBody(outerMost);
-            lastModified = doWhileFalse;
+            lastModified = labelledBlock;
         }
     }
 

jode/src/net/sf/jode/flow/LabelledBlock.java

@@ -0,0 +1,161 @@
+/* LoopBlock Copyright (C) 1998-2002 Jochen Hoenicke.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; see the file COPYING.LESSER.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id: LoopBlock.java 1411 2012-03-01 22:39:08Z hoenicke $
+ */
+
+package net.sf.jode.flow;
+import net.sf.jode.decompiler.TabbedPrintWriter;
+
+/**
+ * This is the structured block for an Loop block.
+ */
+public class LabelledBlock extends StructuredBlock implements BreakableBlock {
+
+    /**
+     * The body of this labelled block.  This is always a valid block and not null.
+     */
+    StructuredBlock bodyBlock;
+
+    /**
+     * The stack after the break.
+     */
+    VariableStack breakedStack;
+
+    /**
+     * The serial number for labels.
+     */
+    static int serialno = 0;
+
+    /**
+     * The label of this instruction, or null if it needs no label.
+     */
+    String label = null;
+
+    public LabelledBlock() {
+    }
+
+    public void setBody(StructuredBlock body) {
+        bodyBlock = body;
+        bodyBlock.outer = this;
+        body.setFlowBlock(flowBlock);
+    }
+
+    /**
+     * Replaces the given sub block with a new block.
+     * @param oldBlock the old sub block.
+     * @param newBlock the new sub block.
+     * @return false, if oldBlock wasn't a direct sub block.
+     */
+    public boolean replaceSubBlock(StructuredBlock oldBlock, 
+                                   StructuredBlock newBlock) {
+        if (bodyBlock != oldBlock)
+            return false;
+        
+        bodyBlock = newBlock;
+	newBlock.outer = this;
+	oldBlock.outer = null;
+        return true;
+    }
+
+    /**
+     * Returns all sub block of this structured block.
+     */
+    public StructuredBlock[] getSubBlocks() {
+        return new StructuredBlock[] { bodyBlock };
+    }
+
+    public void dumpSource(TabbedPrintWriter writer) 
+	throws java.io.IOException
+    {
+        super.dumpSource(writer);
+    }
+
+    public void dumpInstruction(TabbedPrintWriter writer) 
+	throws java.io.IOException
+    {
+        if (label != null) {
+            writer.untab();
+            writer.println(label+":");
+            writer.tab();
+        }
+        boolean needBrace = bodyBlock.needsBraces();
+	if (needBrace)
+	    writer.openBrace();
+	else
+	    writer.println();
+        writer.tab();
+        bodyBlock.dumpSource(writer);
+        writer.untab();
+        writer.closeBrace();
+    }
+
+    /**
+     * Returns the label of this block and creates a new label, if
+     * there wasn't a label previously.
+     */
+    public String getLabel() {
+        if (label == null)
+            label = "label_"+(serialno++);
+        return label;
+    }
+
+    /**
+     * Is called by BreakBlock, to tell us that this block is breaked.
+     */
+    public void setBreaked() {
+    }
+
+    /** 
+     * This is called after the analysis is completely done.  It
+     * will remove all PUSH/stack_i expressions, (if the bytecode
+     * is correct).
+     * @param stack the stack at begin of the block
+     * @return null if there is no way to the end of this block,
+     * otherwise the stack after the block has executed.  
+     */
+    public VariableStack mapStackToLocal(VariableStack stack) {
+	VariableStack afterBody = bodyBlock.mapStackToLocal(stack);
+	mergeBreakedStack(afterBody);
+	return breakedStack;
+    }
+
+    /**
+     * Is called by BreakBlock, to tell us what the stack can be after a
+     * break.
+     * @return false if the stack is inconsistent.
+     */
+    public void mergeBreakedStack(VariableStack stack) {
+	if (breakedStack != null)
+	    breakedStack.merge(stack);
+	else
+	    breakedStack = stack;
+    }
+
+    public void removePush() {
+	bodyBlock.removePush();
+    }
+
+    /**
+     * Determines if there is a sub block, that flows through to the end
+     * of this block.  If this returns true, you know that jump is null.
+     * @return true, if the jump may be safely changed.
+     */
+    public boolean jumpMayBeChanged() {
+        return false;
+    }
+}
+

jode/src/net/sf/jode/flow/StructuredBlock.java

@@ -336,8 +336,11 @@ public abstract class StructuredBlock {
                 if (jump != null)
                     outer.getSubBlocks()[0].moveJump(jump);
                 outer.getSubBlocks()[0].replace(outer);
-            } else
+            } else {
+        	if (outer.jump != null)
+        	    outer.getSubBlocks()[1].moveJump(outer.jump);
                 outer.getSubBlocks()[1].replace(outer);
+            }
             return;
         }