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renamed T1<->T2, since this is, how it is in the dragon book

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check that switchBlock.caseBlocks[i].subBlock is an empty block, before
doing any trafo (should always be the case).


git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@722 379699f6-c40d-0410-875b-85095c16579e
stable
jochen 26 years ago
parent ff44d136a5
commit abb704e316
1 changed files with 25 additions and 22 deletions
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  1. 47
      jode/jode/flow/FlowBlock.java

47
jode/jode/flow/FlowBlock.java
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@ -36,6 +36,9 @@ import jode.util.SimpleDictionary;
* We do a T1/T2 analysis to combine all flow blocks to a single. If * We do a T1/T2 analysis to combine all flow blocks to a single. If
* the graph isn't reducible that doesn't work, but java can only * the graph isn't reducible that doesn't work, but java can only
* produce reducible flow graphs. * produce reducible flow graphs.
*
* We don't use the notion of basic flow graphs. A flow block may be
* anything from a single bytecode opcode, to the whole method.
*/ */
public class FlowBlock { public class FlowBlock {
@ -609,7 +612,7 @@ public class FlowBlock {
/** /**
* Updates the in/out-Vectors of the structured block of the * Updates the in/out-Vectors of the structured block of the
* successing flow block simultanous to a T1 transformation. * successing flow block simultanous to a T2 transformation.
* @param successor The flow block which is unified with this flow * @param successor The flow block which is unified with this flow
* block. * block.
* @param jumps The list of jumps to successor in this block. * @param jumps The list of jumps to successor in this block.
@ -743,7 +746,7 @@ public class FlowBlock {
/** /**
* This is a special T1 transformation, that does also succeed, if * This is a special T2 transformation, that does also succeed, if
* the jumps in the flow block are not yet resolved. But it has * the jumps in the flow block are not yet resolved. But it has
* a special precondition: The succ must be a simple instruction block, * a special precondition: The succ must be a simple instruction block,
* mustn't have another predecessor and all structured blocks in this * mustn't have another predecessor and all structured blocks in this
@ -751,7 +754,7 @@ public class FlowBlock {
* @param succ The successing structured block that should be merged. * @param succ The successing structured block that should be merged.
* @param length the length of the structured block. * @param length the length of the structured block.
*/ */
public void doSequentialT1(StructuredBlock succ, int length) { public void doSequentialT2(StructuredBlock succ, int length) {
checkConsistent(); checkConsistent();
if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_FLOW) != 0) { if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_FLOW) != 0) {
GlobalOptions.err.println("merging sequentialBlock: "+this); GlobalOptions.err.println("merging sequentialBlock: "+this);
@ -804,12 +807,12 @@ public class FlowBlock {
} }
/** /**
* Do a T1 transformation with succ if possible. It is possible, * Do a T2 transformation with succ if possible. It is possible,
* iff succ has exactly this block as predecessor. * iff succ has exactly this block as predecessor.
* @param succ the successor block, must be a valid successor of this * @param succ the successor block, must be a valid successor of this
* block, i.e. not null * block, i.e. not null
*/ */
public boolean doT1(FlowBlock succ) { public boolean doT2(FlowBlock succ) {
/* check if this successor has only this block as predecessor. /* check if this successor has only this block as predecessor.
* if the predecessor is not unique, return false. */ * if the predecessor is not unique, return false. */
if (succ.predecessors.size() != 1 || if (succ.predecessors.size() != 1 ||
@ -846,7 +849,7 @@ public class FlowBlock {
/* Set addr and length to correct value and update nextByAddr */ /* Set addr and length to correct value and update nextByAddr */
mergeAddr(succ); mergeAddr(succ);
/* T1 transformation succeeded */ /* T2 transformation succeeded */
checkConsistent(); checkConsistent();
return true; return true;
} }
@ -890,7 +893,7 @@ public class FlowBlock {
// } // }
// } // }
public boolean doT2(int start, int end) { public boolean doT1(int start, int end) {
/* If there are no jumps to the beginning of this flow block /* If there are no jumps to the beginning of this flow block
* or if this block has other predecessors with a not yet * or if this block has other predecessors with a not yet
* considered address, return false. The second condition * considered address, return false. The second condition
@ -1049,7 +1052,7 @@ public class FlowBlock {
doTransformations(); doTransformations();
// mergeCondition(); // mergeCondition();
/* T2 analysis succeeded */ /* T1 analysis succeeded */
checkConsistent(); checkConsistent();
return true; return true;
@ -1057,7 +1060,7 @@ public class FlowBlock {
/** /**
* Do a T1 transformation with the end_of_method block. * Do a T2 transformation with the end_of_method block.
*/ */
public void mergeEndBlock() { public void mergeEndBlock() {
checkConsistent(); checkConsistent();
@ -1201,16 +1204,16 @@ public class FlowBlock {
} }
if (doT2(start, end)) { if (doT1(start, end)) {
if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_FLOW) != 0) if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_FLOW) != 0)
GlobalOptions.err.println("after T2: "+this); GlobalOptions.err.println("after T1: "+this);
if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_ANALYZE) != 0) if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_ANALYZE) != 0)
GlobalOptions.err.println("T2("+addr+","+getNextAddr() GlobalOptions.err.println("T1("+addr+","+getNextAddr()
+") succeeded"); +") succeeded");
/* T2 transformation succeeded. This may /* T1 transformation succeeded. This may
* make another T1 analysis in the previous * make another T2 analysis in the previous
* block possible. * block possible.
*/ */
if (addr != 0) if (addr != 0)
@ -1220,7 +1223,7 @@ public class FlowBlock {
FlowBlock succ = getSuccessor(start, end); FlowBlock succ = getSuccessor(start, end);
while (true) { while (true) {
if (succ == null) { if (succ == null) {
/* the Block has no successor where t1 is applicable. /* the Block has no successor where T2 is applicable.
* Finish this analyzation. * Finish this analyzation.
*/ */
if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_ANALYZE) != 0) if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_ANALYZE) != 0)
@ -1231,14 +1234,14 @@ public class FlowBlock {
return changed; return changed;
} else { } else {
if ((nextByAddr == succ || succ.nextByAddr == this) if ((nextByAddr == succ || succ.nextByAddr == this)
/* Only do T1 transformation if the blocks are /* Only do T2 transformation if the blocks are
* adjacent. */ * adjacent. */
&& doT1(succ)) { && doT2(succ)) {
/* T1 transformation succeeded. */ /* T2 transformation succeeded. */
changed = true; changed = true;
if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_FLOW) != 0) if ((GlobalOptions.debuggingFlags & GlobalOptions.DEBUG_FLOW) != 0)
GlobalOptions.err.println("after T1: "+this); GlobalOptions.err.println("after T2: "+this);
break; break;
} }
@ -1280,7 +1283,7 @@ public class FlowBlock {
} }
/** /**
* The switch analyzation. This calls doSwitchT1 and doT2 on apropriate * The switch analyzation. This calls doSwitchT2 and doT1 on apropriate
* regions. Only blocks whose address lies in the given address * regions. Only blocks whose address lies in the given address
* range are considered and it is taken care of, that the switch * range are considered and it is taken care of, that the switch
* is never leaved. <p> * is never leaved. <p>
@ -1295,7 +1298,7 @@ public class FlowBlock {
int last = -1; int last = -1;
FlowBlock lastFlow = null; FlowBlock lastFlow = null;
for (int i=0; i < switchBlock.caseBlocks.length; i++) { for (int i=0; i < switchBlock.caseBlocks.length; i++) {
if (switchBlock.caseBlocks[i].subBlock != null if (switchBlock.caseBlocks[i].subBlock instanceof EmptyBlock
&& switchBlock.caseBlocks[i].subBlock.jump != null) { && switchBlock.caseBlocks[i].subBlock.jump != null) {
FlowBlock nextFlow = switchBlock.caseBlocks[i]. FlowBlock nextFlow = switchBlock.caseBlocks[i].
subBlock.jump.destination; subBlock.jump.destination;
@ -1304,7 +1307,7 @@ public class FlowBlock {
else if (nextFlow.addr >= start) { else if (nextFlow.addr >= start) {
/* First analyze the nextFlow block. It may /* First analyze the nextFlow block. It may
* return early after a T2 trafo so call it * return early after a T1 trafo so call it
* until nothing more is possible. * until nothing more is possible.
*/ */
while (nextFlow.analyze(getNextAddr(), end)) while (nextFlow.analyze(getNextAddr(), end))

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