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core: redone return blocks splitting for fix issue #4

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This commit is contained in:
Skylot
2013-12-12 21:19:22 +04:00
parent e54b764588
commit e46dfc555e
5 changed files with 191 additions and 89 deletions
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jadx-core/src/main/java/jadx/core/dex/visitors/BlockMakerVisitor.java
+135 -80
View File
@@ -8,6 +8,7 @@ import jadx.core.dex.attributes.JumpAttribute;
import jadx.core.dex.attributes.LoopAttr;
import jadx.core.dex.instructions.IfNode;
import jadx.core.dex.instructions.InsnType;
import jadx.core.dex.instructions.args.ArgType;
import jadx.core.dex.instructions.args.InsnArg;
import jadx.core.dex.instructions.args.RegisterArg;
import jadx.core.dex.nodes.BlockNode;
@@ -22,6 +23,7 @@ import java.util.ArrayList;
import java.util.BitSet;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
@@ -40,9 +42,9 @@ public class BlockMakerVisitor extends AbstractVisitor {
@Override
public void visit(MethodNode mth) {
if (mth.isNoCode())
if (mth.isNoCode()) {
return;
}
mth.initBasicBlocks();
makeBasicBlocks(mth);
BlockProcessingHelper.visit(mth);
@@ -67,12 +69,14 @@ public class BlockMakerVisitor extends AbstractVisitor {
|| type == InsnType.THROW
|| SEPARATE_INSNS.contains(type)) {
if (type == InsnType.RETURN || type == InsnType.THROW)
if (type == InsnType.RETURN || type == InsnType.THROW) {
mth.addExitBlock(curBlock);
}
BlockNode block = startNewBlock(mth, insn.getOffset());
if (type == InsnType.MONITOR_ENTER || type == InsnType.MONITOR_EXIT)
if (type == InsnType.MONITOR_ENTER || type == InsnType.MONITOR_EXIT) {
connect(curBlock, block);
}
curBlock = block;
startNew = true;
} else {
@@ -83,8 +87,9 @@ public class BlockMakerVisitor extends AbstractVisitor {
if (pjumps.size() > 0) {
for (IAttribute j : pjumps) {
JumpAttribute jump = (JumpAttribute) j;
if (jump.getSrc() == prevInsn.getOffset())
if (jump.getSrc() == prevInsn.getOffset()) {
startNew = true;
}
}
}
@@ -92,8 +97,9 @@ public class BlockMakerVisitor extends AbstractVisitor {
if (cjumps.size() > 0) {
for (IAttribute j : cjumps) {
JumpAttribute jump = (JumpAttribute) j;
if (jump.getDest() == insn.getOffset())
if (jump.getDest() == insn.getOffset()) {
startNew = true;
}
}
}
@@ -101,8 +107,9 @@ public class BlockMakerVisitor extends AbstractVisitor {
if (type == InsnType.IF) {
IfNode ifs = (IfNode) (insn);
BlockNode targBlock = blocksMap.get(ifs.getTarget());
if (targBlock == curBlock)
if (targBlock == curBlock) {
startNew = true;
}
}
if (startNew) {
@@ -158,8 +165,9 @@ public class BlockMakerVisitor extends AbstractVisitor {
for (ExceptionHandler h : catches.getTryBlock().getHandlers()) {
BlockNode destBlock = getBlock(h.getHandleOffset(), blocksMap);
// skip self loop in handler
if (connBlock != destBlock)
if (connBlock != destBlock) {
connect(connBlock, destBlock);
}
}
}
}
@@ -177,8 +185,9 @@ public class BlockMakerVisitor extends AbstractVisitor {
markReturnBlocks(mth);
i++;
if (i > 100)
if (i > 100) {
throw new AssertionError("Can't fix method cfg: " + mth);
}
}
registerLoops(mth);
@@ -191,10 +200,12 @@ public class BlockMakerVisitor extends AbstractVisitor {
}
private static void connect(BlockNode from, BlockNode to) {
if (!from.getSuccessors().contains(to))
if (!from.getSuccessors().contains(to)) {
from.getSuccessors().add(to);
if (!to.getPredecessors().contains(from))
}
if (!to.getPredecessors().contains(from)) {
to.getPredecessors().add(from);
}
}
private static void removeConnection(BlockNode from, BlockNode to) {
@@ -227,20 +238,19 @@ public class BlockMakerVisitor extends AbstractVisitor {
do {
changed = false;
for (BlockNode block : basicBlocks) {
if (block == entryBlock)
if (block == entryBlock) {
continue;
}
BitSet d = block.getDoms();
dset.clear();
dset.or(d);
for (BlockNode pred : block.getPredecessors()) {
d.and(pred.getDoms());
}
d.set(block.getId());
if (!d.equals(dset))
if (!d.equals(dset)) {
changed = true;
}
}
} while (changed);
@@ -253,9 +263,9 @@ public class BlockMakerVisitor extends AbstractVisitor {
// calculate immediate dominators
for (BlockNode block : basicBlocks) {
if (block == entryBlock)
if (block == entryBlock) {
continue;
}
List<BlockNode> preds = block.getPredecessors();
if (preds.size() == 1) {
block.setIDom(preds.get(0));
@@ -300,11 +310,14 @@ public class BlockMakerVisitor extends AbstractVisitor {
}
private static void markReturnBlocks(MethodNode mth) {
mth.getExitBlocks().clear();
for (BlockNode block : mth.getBasicBlocks()) {
List<InsnNode> insns = block.getInstructions();
if (insns.size() == 1) {
if (insns.get(0).getType() == InsnType.RETURN)
if (insns.get(0).getType() == InsnType.RETURN) {
block.getAttributes().add(AttributeFlag.RETURN);
mth.getExitBlocks().add(block);
}
}
}
}
@@ -350,72 +363,114 @@ public class BlockMakerVisitor extends AbstractVisitor {
}
}
}
// splice return block if several predecessors presents
for (BlockNode block : mth.getExitBlocks()) {
if (block.getInstructions().size() == 1
&& !block.getInstructions().get(0).getAttributes().contains(AttributeType.CATCH_BLOCK)
&& !block.getAttributes().contains(AttributeFlag.SYNTHETIC)) {
List<BlockNode> preds = new ArrayList<BlockNode>(block.getPredecessors());
InsnNode origReturnInsn = block.getInstructions().get(0);
RegisterArg retArg = null;
if (origReturnInsn.getArgsCount() != 0)
retArg = (RegisterArg) origReturnInsn.getArg(0);
for (BlockNode pred : preds) {
BlockNode newRetBlock;
InsnNode predInsn = pred.getInstructions().get(0);
switch (predInsn.getType()) {
case IF:
// make copy of return block and connect to predecessor
newRetBlock = startNewBlock(mth, block.getStartOffset());
newRetBlock.getAttributes().add(AttributeFlag.SYNTHETIC);
List<BlockNode> successors = pred.getSuccessors();
if (successors.get(0) == block) {
successors.set(0, newRetBlock);
} else if (successors.get(1) == block){
successors.set(1, newRetBlock);
}
block.getPredecessors().remove(pred);
newRetBlock.getPredecessors().add(pred);
break;
case SWITCH:
// TODO: is it ok to just skip this predecessor?
block.getAttributes().add(AttributeFlag.SYNTHETIC);
continue;
default:
removeConnection(pred, block);
newRetBlock = pred;
break;
}
InsnNode ret = new InsnNode(InsnType.RETURN, 1);
if (retArg != null) {
ret.addArg(InsnArg.reg(retArg.getRegNum(), retArg.getType()));
ret.getArg(0).forceSetTypedVar(retArg.getTypedVar());
}
ret.getAttributes().addAll(origReturnInsn.getAttributes());
newRetBlock.getInstructions().add(ret);
newRetBlock.getAttributes().add(AttributeFlag.RETURN);
mth.addExitBlock(newRetBlock);
}
if (block.getPredecessors().size() == 0) {
mth.getBasicBlocks().remove(block);
mth.getExitBlocks().remove(block);
return true;
}
return block.getAttributes().contains(AttributeFlag.SYNTHETIC);
}
if (splitReturn(mth)) {
return true;
}
if (mergeReturn(mth)) {
return true;
}
// TODO detect ternary operator
return false;
}
/**
* Merge return blocks for void methods
*/
private static boolean mergeReturn(MethodNode mth) {
if (mth.getExitBlocks().size() == 1 || !mth.getReturnType().equals(ArgType.VOID)) {
return false;
}
boolean merge = false;
for (BlockNode exitBlock : mth.getExitBlocks()) {
List<BlockNode> preds = exitBlock.getPredecessors();
if (preds.size() == 1) {
BlockNode pred = preds.get(0);
for (BlockNode otherExitBlock : mth.getExitBlocks()) {
if (exitBlock != otherExitBlock
&& otherExitBlock.isDominator(pred)
&& otherExitBlock.getPredecessors().size() == 1) {
// merge
BlockNode otherPred = otherExitBlock.getPredecessors().get(0);
removeConnection(otherPred, otherExitBlock);
connect(otherPred, exitBlock);
merge = true;
}
}
}
}
if (merge) {
cleanExitNodes(mth);
}
return merge;
}
/**
* Splice return block if several predecessors presents
*/
private static boolean splitReturn(MethodNode mth) {
if (mth.getExitBlocks().size() != 1) {
return false;
}
boolean split = false;
BlockNode exitBlock = mth.getExitBlocks().get(0);
if (exitBlock.getPredecessors().size() > 1
&& exitBlock.getInstructions().size() == 1
&& !exitBlock.getInstructions().get(0).getAttributes().contains(AttributeType.CATCH_BLOCK)
&& !exitBlock.getAttributes().contains(AttributeFlag.SYNTHETIC)) {
InsnNode returnInsn = exitBlock.getInstructions().get(0);
List<BlockNode> preds = new ArrayList<BlockNode>(exitBlock.getPredecessors());
if (returnInsn.getArgsCount() != 0 && !isReturnArgAssignInPred(mth, preds, returnInsn)) {
return false;
}
split = true;
for (BlockNode pred : preds) {
BlockNode newRetBlock = startNewBlock(mth, exitBlock.getStartOffset());
newRetBlock.getAttributes().add(AttributeFlag.SYNTHETIC);
newRetBlock.getInstructions().add(duplicateReturnInsn(returnInsn));
removeConnection(pred, exitBlock);
connect(pred, newRetBlock);
}
}
if (split) {
cleanExitNodes(mth);
}
return split;
}
private static boolean isReturnArgAssignInPred(MethodNode mth, List<BlockNode> preds, InsnNode returnInsn) {
RegisterArg arg = (RegisterArg) returnInsn.getArg(0);
int regNum = arg.getRegNum();
for (BlockNode pred : preds) {
for (InsnNode insnNode : pred.getInstructions()) {
RegisterArg result = insnNode.getResult();
if (result != null && result.getRegNum() == regNum) {
return true;
}
}
}
return false;
}
private static void cleanExitNodes(MethodNode mth) {
for (Iterator<BlockNode> iterator = mth.getExitBlocks().iterator(); iterator.hasNext(); ) {
BlockNode exitBlock = iterator.next();
if (exitBlock.getPredecessors().isEmpty()) {
mth.getBasicBlocks().remove(exitBlock);
iterator.remove();
}
}
}
private static InsnNode duplicateReturnInsn(InsnNode returnInsn) {
InsnNode insn = new InsnNode(returnInsn.getType(), returnInsn.getArgsCount());
if (returnInsn.getArgsCount() != 0) {
RegisterArg arg = (RegisterArg) returnInsn.getArg(0);
insn.addArg(InsnArg.reg(arg.getRegNum(), arg.getType()));
}
insn.getAttributes().addAll(returnInsn.getAttributes());
return insn;
}
private static void cleanDomTree(MethodNode mth) {
for (BlockNode block : mth.getBasicBlocks()) {
AttributesList attrs = block.getAttributes();
jadx-core/src/main/java/jadx/core/dex/visitors/regions/FinishRegions.java
+3 -4
View File
@@ -1,16 +1,12 @@
package jadx.core.dex.visitors.regions;
import jadx.core.dex.instructions.InsnType;
import jadx.core.dex.instructions.args.ArgType;
import jadx.core.dex.nodes.BlockNode;
import jadx.core.dex.nodes.IBlock;
import jadx.core.dex.nodes.IRegion;
import jadx.core.dex.nodes.InsnNode;
import jadx.core.dex.nodes.MethodNode;
import jadx.core.dex.regions.LoopRegion;
import java.util.Iterator;
import java.util.List;
public class FinishRegions extends TracedRegionVisitor {
@Override
@@ -21,6 +17,8 @@ public class FinishRegions extends TracedRegionVisitor {
BlockNode block = (BlockNode) container;
// remove last return in void functions
/*
BlockNode block = (BlockNode) container;
if (block.getCleanSuccessors().isEmpty()
&& mth.getReturnType().equals(ArgType.VOID)) {
List<InsnNode> insns = block.getInstructions();
@@ -33,6 +31,7 @@ public class FinishRegions extends TracedRegionVisitor {
}
}
}
*/
}
private boolean blockNotInLoop(MethodNode mth, BlockNode block) {
jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMaker.java
+4 -3
View File
@@ -4,7 +4,6 @@ import jadx.core.Consts;
import jadx.core.dex.attributes.AttributeFlag;
import jadx.core.dex.attributes.AttributeType;
import jadx.core.dex.attributes.AttributesList;
import jadx.core.dex.attributes.ForceReturnAttr;
import jadx.core.dex.attributes.IAttribute;
import jadx.core.dex.attributes.LoopAttr;
import jadx.core.dex.instructions.IfNode;
@@ -258,6 +257,7 @@ public class RegionMaker {
while (next != null) {
if (isPathExists(loopExit, next)) {
// found cross
/*
if (next.getCleanSuccessors().size() == 1) {
BlockNode r = BlockUtils.getNextBlock(next);
if (r != null
@@ -265,13 +265,14 @@ public class RegionMaker {
&& r.getInstructions().size() > 0
&& r.getInstructions().get(0).getType() == InsnType.RETURN) {
next.getAttributes().add(new ForceReturnAttr(r.getInstructions().get(0)));
} /*/ else {
} else {
next.getAttributes().add(AttributeFlag.BREAK);
stack.addExit(r);
} /**/
}
} else {
stack.addExit(next);
}
*/
break;
}
next = BlockUtils.getNextBlock(next);
jadx-core/src/main/java/jadx/core/dex/visitors/typeresolver/TypeResolver.java
+1 -2
View File
@@ -67,8 +67,7 @@ public class TypeResolver extends AbstractVisitor {
state.assignReg(insn.getResult());
}
if (block.getSuccessors().size() > 0)
block.setEndState(new BlockRegState(state));
block.setEndState(new BlockRegState(state));
}
}
jadx-samples/src/main/java/jadx/samples/TestCF4.java
+48
View File
@@ -0,0 +1,48 @@
package jadx.samples;
public class TestCF4 extends AbstractTest {
int c;
String d;
String f;
public void testComplexIf(String a, int b) {
if (d == null || (c == 0 && b != -1 && d.length() == 0)) {
c = a.codePointAt(c);
} else {
if (a.length() != 2) {
c = f.compareTo(a);
}
}
}
public void checkComplexIf() {
d = null;
f = null;
c = 2;
testComplexIf("abcdef", 0);
assertEquals(c, (int) 'c');
d = "";
f = null;
c = 0;
testComplexIf("abcdef", 0);
assertEquals(c, (int) 'a');
d = "";
f = "1";
c = 777;
testComplexIf("ab", -1);
assertEquals(c, 777);
}
@Override
public boolean testRun() throws Exception {
checkComplexIf();
return true;
}
public static void main(String[] args) throws Exception {
new TestCF4().testRun();
}
}