private static void renameVar(MethodNode mth, SSAVar[] vars, int[] vers, BlockNode block) {
SSAVar[] inputVars = Arrays.copyOf(vars, vars.length);
for (InsnNode insn : block.getInstructions()) {
if (insn.getType() != InsnType.PHI) {
for (InsnArg arg : insn.getArguments()) {
if (!arg.isRegister()) {
continue;
}
RegisterArg reg = (RegisterArg) arg;
int regNum = reg.getRegNum();
SSAVar var = vars[regNum];
if (var == null) {
throw new JadxRuntimeException(
"Not initialized variable reg: "
+ regNum
+ ", insn: "
+ insn
+ ", block:"
+ block
+ ", method: "
+ mth);
}
var.use(reg);
}
}
RegisterArg result = insn.getResult();
if (result != null) {
int regNum = result.getRegNum();
vars[regNum] = mth.makeNewSVar(regNum, vers, result);
}
}
for (BlockNode s : block.getSuccessors()) {
PhiListAttr phiList = s.get(AType.PHI_LIST);
if (phiList == null) {
continue;
}
int j = s.getPredecessors().indexOf(block);
if (j == -1) {
throw new JadxRuntimeException("Can't find predecessor for " + block + " " + s);
}
for (PhiInsn phiInsn : phiList.getList()) {
if (j >= phiInsn.getArgsCount()) {
continue;
}
int regNum = phiInsn.getResult().getRegNum();
SSAVar var = vars[regNum];
if (var == null) {
continue;
}
var.use(phiInsn.getArg(j));
var.setUsedInPhi(phiInsn);
}
}
for (BlockNode domOn : block.getDominatesOn()) {
renameVar(mth, vars, vers, domOn);
}
System.arraycopy(inputVars, 0, vars, 0, vars.length);
}
private boolean insertBreak(RegionStack stack, BlockNode loopExit, Edge exitEdge) {
BlockNode exit = exitEdge.getTarget();
BlockNode insertBlock = null;
boolean confirm = false;
// process special cases
if (loopExit == exit) {
// try/catch at loop end
BlockNode source = exitEdge.getSource();
if (source.contains(AType.CATCH_BLOCK) && source.getSuccessors().size() == 2) {
BlockNode other = BlockUtils.selectOther(loopExit, source.getSuccessors());
if (other != null) {
other = BlockUtils.skipSyntheticSuccessor(other);
if (other.contains(AType.EXC_HANDLER)) {
insertBlock = source;
confirm = true;
}
}
}
}
if (!confirm) {
while (exit != null) {
if (insertBlock != null && isPathExists(loopExit, exit)) {
// found cross
if (canInsertBreak(insertBlock)) {
confirm = true;
break;
}
return false;
}
insertBlock = exit;
List<BlockNode> cs = exit.getCleanSuccessors();
exit = cs.size() == 1 ? cs.get(0) : null;
}
}
if (!confirm) {
return false;
}
InsnNode breakInsn = new InsnNode(InsnType.BREAK, 0);
insertBlock.getInstructions().add(breakInsn);
stack.addExit(exit);
// add label to 'break' if needed
addBreakLabel(exitEdge, exit, breakInsn);
return true;
}
/** Traverse from monitor-enter thru successors and collect blocks contains monitor-exit */
private static void traverseMonitorExits(
SynchronizedRegion region,
InsnArg arg,
BlockNode block,
Set<BlockNode> exits,
Set<BlockNode> visited) {
visited.add(block);
for (InsnNode insn : block.getInstructions()) {
if (insn.getType() == InsnType.MONITOR_EXIT && insn.getArg(0).equals(arg)) {
exits.add(block);
region.getExitInsns().add(insn);
return;
}
}
for (BlockNode node : block.getSuccessors()) {
if (!visited.contains(node)) {
traverseMonitorExits(region, arg, node, exits, visited);
}
}
}
private boolean canInsertBreak(BlockNode exit) {
if (exit.contains(AFlag.RETURN) || BlockUtils.checkLastInsnType(exit, InsnType.BREAK)) {
return false;
}
List<BlockNode> simplePath = BlockUtils.buildSimplePath(exit);
if (!simplePath.isEmpty()) {
BlockNode lastBlock = simplePath.get(simplePath.size() - 1);
if (lastBlock.contains(AFlag.RETURN) || lastBlock.getSuccessors().isEmpty()) {
return false;
}
}
// check if there no outer switch (TODO: very expensive check)
Set<BlockNode> paths = BlockUtils.getAllPathsBlocks(mth.getEnterBlock(), exit);
for (BlockNode block : paths) {
if (BlockUtils.checkLastInsnType(block, InsnType.SWITCH)) {
return false;
}
}
return true;
}
public void processTryCatchBlocks(MethodNode mth) {
Set<TryCatchBlock> tcs = new HashSet<TryCatchBlock>();
for (ExceptionHandler handler : mth.getExceptionHandlers()) {
tcs.add(handler.getTryBlock());
}
for (TryCatchBlock tc : tcs) {
List<BlockNode> blocks = new ArrayList<BlockNode>(tc.getHandlersCount());
Set<BlockNode> splitters = new HashSet<BlockNode>();
for (ExceptionHandler handler : tc.getHandlers()) {
BlockNode handlerBlock = handler.getHandlerBlock();
if (handlerBlock != null) {
blocks.add(handlerBlock);
splitters.addAll(handlerBlock.getPredecessors());
} else {
LOG.debug(ErrorsCounter.formatErrorMsg(mth, "No exception handler block: " + handler));
}
}
Set<BlockNode> exits = new HashSet<BlockNode>();
for (BlockNode splitter : splitters) {
for (BlockNode handler : blocks) {
List<BlockNode> s = splitter.getSuccessors();
if (s.isEmpty()) {
LOG.debug(ErrorsCounter.formatErrorMsg(mth, "No successors for splitter: " + splitter));
continue;
}
BlockNode ss = s.get(0);
BlockNode cross = BlockUtils.getPathCross(mth, ss, handler);
if (cross != null && cross != ss && cross != handler) {
exits.add(cross);
}
}
}
for (ExceptionHandler handler : tc.getHandlers()) {
processExcHandler(handler, exits);
}
}
}
private BlockNode processSwitch(
IRegion currentRegion, BlockNode block, SwitchNode insn, RegionStack stack) {
SwitchRegion sw = new SwitchRegion(currentRegion, block);
currentRegion.getSubBlocks().add(sw);
int len = insn.getTargets().length;
// sort by target
Map<Integer, List<Object>> casesMap = new LinkedHashMap<Integer, List<Object>>(len);
for (int i = 0; i < len; i++) {
Object key = insn.getKeys()[i];
int targ = insn.getTargets()[i];
List<Object> keys = casesMap.get(targ);
if (keys == null) {
keys = new ArrayList<Object>(2);
casesMap.put(targ, keys);
}
keys.add(key);
}
Map<BlockNode, List<Object>> blocksMap = new LinkedHashMap<BlockNode, List<Object>>(len);
for (Map.Entry<Integer, List<Object>> entry : casesMap.entrySet()) {
BlockNode c = getBlockByOffset(entry.getKey(), block.getSuccessors());
assert c != null;
blocksMap.put(c, entry.getValue());
}
BlockNode defCase = getBlockByOffset(insn.getDefaultCaseOffset(), block.getSuccessors());
if (defCase != null) {
blocksMap.remove(defCase);
}
LoopInfo loop = mth.getLoopForBlock(block);
Map<BlockNode, BlockNode> fallThroughCases = new LinkedHashMap<BlockNode, BlockNode>();
List<BlockNode> basicBlocks = mth.getBasicBlocks();
BitSet outs = new BitSet(basicBlocks.size());
outs.or(block.getDomFrontier());
for (BlockNode s : block.getCleanSuccessors()) {
BitSet df = s.getDomFrontier();
// fall through case block
if (df.cardinality() > 1) {
if (df.cardinality() > 2) {
LOG.debug("Unexpected case pattern, block: {}, mth: {}", s, mth);
} else {
BlockNode first = basicBlocks.get(df.nextSetBit(0));
BlockNode second = basicBlocks.get(df.nextSetBit(first.getId() + 1));
if (second.getDomFrontier().get(first.getId())) {
fallThroughCases.put(s, second);
df = new BitSet(df.size());
df.set(first.getId());
} else if (first.getDomFrontier().get(second.getId())) {
fallThroughCases.put(s, first);
df = new BitSet(df.size());
df.set(second.getId());
}
}
}
outs.or(df);
}
outs.clear(block.getId());
if (loop != null) {
outs.clear(loop.getStart().getId());
}
stack.push(sw);
stack.addExits(BlockUtils.bitSetToBlocks(mth, outs));
// check cases order if fall through case exists
if (!fallThroughCases.isEmpty()) {
if (isBadCasesOrder(blocksMap, fallThroughCases)) {
LOG.debug("Fixing incorrect switch cases order, method: {}", mth);
blocksMap = reOrderSwitchCases(blocksMap, fallThroughCases);
if (isBadCasesOrder(blocksMap, fallThroughCases)) {
LOG.error("Can't fix incorrect switch cases order, method: {}", mth);
mth.add(AFlag.INCONSISTENT_CODE);
}
}
}
// filter 'out' block
if (outs.cardinality() > 1) {
// remove exception handlers
BlockUtils.cleanBitSet(mth, outs);
}
if (outs.cardinality() > 1) {
// filter loop start and successors of other blocks
for (int i = outs.nextSetBit(0); i >= 0; i = outs.nextSetBit(i + 1)) {
BlockNode b = basicBlocks.get(i);
outs.andNot(b.getDomFrontier());
if (b.contains(AFlag.LOOP_START)) {
outs.clear(b.getId());
} else {
for (BlockNode s : b.getCleanSuccessors()) {
outs.clear(s.getId());
}
}
}
}
if (loop != null && outs.cardinality() > 1) {
outs.clear(loop.getEnd().getId());
}
if (outs.cardinality() == 0) {
// one or several case blocks are empty,
// run expensive algorithm for find 'out' block
for (BlockNode maybeOut : block.getSuccessors()) {
boolean allReached = true;
for (BlockNode s : block.getSuccessors()) {
if (!isPathExists(s, maybeOut)) {
allReached = false;
break;
}
}
if (allReached) {
outs.set(maybeOut.getId());
break;
}
}
}
BlockNode out = null;
if (outs.cardinality() == 1) {
out = basicBlocks.get(outs.nextSetBit(0));
stack.addExit(out);
} else if (loop == null && outs.cardinality() > 1) {
LOG.warn("Can't detect out node for switch block: {} in {}", block, mth);
}
if (loop != null) {
// check if 'continue' must be inserted
BlockNode end = loop.getEnd();
if (out != end && out != null) {
insertContinueInSwitch(block, out, end);
}
}
if (!stack.containsExit(defCase)) {
sw.setDefaultCase(makeRegion(defCase, stack));
}
for (Entry<BlockNode, List<Object>> entry : blocksMap.entrySet()) {
BlockNode caseBlock = entry.getKey();
if (stack.containsExit(caseBlock)) {
// empty case block
sw.addCase(entry.getValue(), new Region(stack.peekRegion()));
} else {
BlockNode next = fallThroughCases.get(caseBlock);
stack.addExit(next);
Region caseRegion = makeRegion(caseBlock, stack);
stack.removeExit(next);
if (next != null) {
next.add(AFlag.FALL_THROUGH);
caseRegion.add(AFlag.FALL_THROUGH);
}
sw.addCase(entry.getValue(), caseRegion);
// 'break' instruction will be inserted in RegionMakerVisitor.PostRegionVisitor
}
}
stack.pop();
return out;
}
