Examples with LoopInfo jadx.core.dex.attributes.nodes.LoopInfo used on opensource projects

Example 1 with LoopInfo

use of jadx.core.dex.attributes.nodes.LoopInfo in project jadx by skylot.

the class RegionMaker method processSwitch.

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());
        if (c == null) {
            throw new JadxRuntimeException("Switch block not found by offset: " + entry.getKey());
        }
        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) {
        // 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;
}

Example 2 with LoopInfo

use of jadx.core.dex.attributes.nodes.LoopInfo in project jadx by skylot.

the class BlockProcessor method processNestedLoops.

private static void processNestedLoops(MethodNode mth) {
    if (mth.getLoopsCount() == 0) {
        return;
    }
    for (LoopInfo outLoop : mth.getLoops()) {
        for (LoopInfo innerLoop : mth.getLoops()) {
            if (outLoop == innerLoop) {
                continue;
            }
            if (outLoop.getLoopBlocks().containsAll(innerLoop.getLoopBlocks())) {
                LoopInfo parentLoop = innerLoop.getParentLoop();
                if (parentLoop != null) {
                    if (parentLoop.getLoopBlocks().containsAll(outLoop.getLoopBlocks())) {
                        outLoop.setParentLoop(parentLoop);
                        innerLoop.setParentLoop(outLoop);
                    } else {
                        parentLoop.setParentLoop(outLoop);
                    }
                } else {
                    innerLoop.setParentLoop(outLoop);
                }
            }
        }
    }
}

Example 3 with LoopInfo

use of jadx.core.dex.attributes.nodes.LoopInfo in project jadx by skylot.

the class BlockProcessor method modifyBlocksTree.

private static boolean modifyBlocksTree(MethodNode mth) {
    for (BlockNode block : mth.getBasicBlocks()) {
        if (block.getPredecessors().isEmpty() && block != mth.getEnterBlock()) {
            throw new JadxRuntimeException("Unreachable block: " + block);
        }
        // check loops
        List<LoopInfo> loops = block.getAll(AType.LOOP);
        if (loops.size() > 1) {
            boolean oneHeader = true;
            for (LoopInfo loop : loops) {
                if (loop.getStart() != block) {
                    oneHeader = false;
                    break;
                }
            }
            if (oneHeader) {
                // several back edges connected to one loop header => make additional block
                BlockNode newLoopHeader = BlockSplitter.startNewBlock(mth, block.getStartOffset());
                newLoopHeader.add(AFlag.SYNTHETIC);
                connect(newLoopHeader, block);
                for (LoopInfo la : loops) {
                    BlockNode node = la.getEnd();
                    removeConnection(node, block);
                    connect(node, newLoopHeader);
                }
                return true;
            }
        }
        if (loops.size() == 1) {
            LoopInfo loop = loops.get(0);
            // insert additional blocks for possible 'break' insertion
            List<Edge> edges = loop.getExitEdges();
            if (!edges.isEmpty()) {
                boolean change = false;
                for (Edge edge : edges) {
                    BlockNode target = edge.getTarget();
                    if (!target.contains(AFlag.SYNTHETIC)) {
                        BlockSplitter.insertBlockBetween(mth, edge.getSource(), target);
                        change = true;
                    }
                }
                if (change) {
                    return true;
                }
            }
            // insert additional blocks for possible 'continue' insertion
            BlockNode loopEnd = loop.getEnd();
            if (loopEnd.getPredecessors().size() > 1) {
                boolean change = false;
                List<BlockNode> nodes = new ArrayList<BlockNode>(loopEnd.getPredecessors());
                for (BlockNode pred : nodes) {
                    if (!pred.contains(AFlag.SYNTHETIC)) {
                        BlockSplitter.insertBlockBetween(mth, pred, loopEnd);
                        change = true;
                    }
                }
                if (change) {
                    return true;
                }
            }
        }
    }
    return splitReturn(mth);
}

Example 4 with LoopInfo

use of jadx.core.dex.attributes.nodes.LoopInfo in project jadx by skylot.

the class BlockNode method cleanSuccessors.

/**
 * Return all successor which are not exception handler or followed by loop back edge
 */
private static List<BlockNode> cleanSuccessors(BlockNode block) {
    List<BlockNode> sucList = block.getSuccessors();
    if (sucList.isEmpty()) {
        return sucList;
    }
    List<BlockNode> toRemove = new ArrayList<>(sucList.size());
    for (BlockNode b : sucList) {
        if (BlockUtils.isExceptionHandlerPath(b)) {
            toRemove.add(b);
        }
    }
    if (block.contains(AFlag.LOOP_END)) {
        List<LoopInfo> loops = block.getAll(AType.LOOP);
        for (LoopInfo loop : loops) {
            toRemove.add(loop.getStart());
        }
    }
    if (toRemove.isEmpty()) {
        return sucList;
    }
    List<BlockNode> result = new ArrayList<>(sucList);
    result.removeAll(toRemove);
    return result;
}

Example 5 with LoopInfo

use of jadx.core.dex.attributes.nodes.LoopInfo in project jadx by skylot.

the class RegionMaker method addBreakLabel.

private void addBreakLabel(Edge exitEdge, BlockNode exit, InsnNode breakInsn) {
    BlockNode outBlock = BlockUtils.getNextBlock(exitEdge.getTarget());
    if (outBlock == null) {
        return;
    }
    List<LoopInfo> exitLoop = mth.getAllLoopsForBlock(outBlock);
    if (!exitLoop.isEmpty()) {
        return;
    }
    List<LoopInfo> inLoops = mth.getAllLoopsForBlock(exitEdge.getSource());
    if (inLoops.size() < 2) {
        return;
    }
    // search for parent loop
    LoopInfo parentLoop = null;
    for (LoopInfo loop : inLoops) {
        if (loop.getParentLoop() == null) {
            parentLoop = loop;
            break;
        }
    }
    if (parentLoop == null) {
        return;
    }
    if (parentLoop.getEnd() != exit && !parentLoop.getExitNodes().contains(exit)) {
        LoopLabelAttr labelAttr = new LoopLabelAttr(parentLoop);
        breakInsn.addAttr(labelAttr);
        parentLoop.getStart().addAttr(labelAttr);
    }
}