Examples with Unit soot.Unit used on opensource projects

Example 66 with Unit

use of soot.Unit in project soot by Sable.

the class DexReturnInliner method internalTransform.

@Override
protected void internalTransform(final Body body, String phaseName, Map<String, String> options) {
    Set<Unit> duplicateIfTargets = getFallThroughReturns(body);
    Iterator<Unit> it = body.getUnits().snapshotIterator();
    boolean mayBeMore = false;
    Unit last = null;
    do {
        mayBeMore = false;
        while (it.hasNext()) {
            Unit u = it.next();
            if (u instanceof GotoStmt) {
                GotoStmt gtStmt = (GotoStmt) u;
                if (isInstanceofReturn(gtStmt.getTarget())) {
                    Stmt stmt = (Stmt) gtStmt.getTarget().clone();
                    for (Trap t : body.getTraps()) for (UnitBox ubox : t.getUnitBoxes()) if (ubox.getUnit() == u)
                        ubox.setUnit(stmt);
                    while (!u.getBoxesPointingToThis().isEmpty()) u.getBoxesPointingToThis().get(0).setUnit(stmt);
                    // the cloned return stmt gets the tags of u
                    stmt.addAllTagsOf(u);
                    body.getUnits().swapWith(u, stmt);
                    mayBeMore = true;
                }
            } else if (u instanceof IfStmt) {
                IfStmt ifstmt = (IfStmt) u;
                Unit t = ifstmt.getTarget();
                if (isInstanceofReturn(t)) {
                    // once, otherwise we will end up with unused copies
                    if (duplicateIfTargets == null)
                        duplicateIfTargets = new HashSet<Unit>();
                    if (!duplicateIfTargets.add(t)) {
                        Unit newTarget = (Unit) t.clone();
                        body.getUnits().addLast(newTarget);
                        ifstmt.setTarget(newTarget);
                    }
                }
            } else if (isInstanceofReturn(u)) {
                // the original return stmt gets the tags of its predecessor
                if (last != null) {
                    u.removeAllTags();
                    u.addAllTagsOf(last);
                }
            }
            last = u;
        }
    } while (mayBeMore);
}

Example 67 with Unit

use of soot.Unit in project soot by Sable.

the class DexReturnValuePropagator method isRedefined.

/**
 * Checks whether the given local has been redefined between the original
 * definition unitDef and the use unitUse.
 * @param l The local for which to check for redefinitions
 * @param unitUse The unit that uses the local
 * @param unitDef The unit that defines the local
 * @param graph The unit graph to use for the check
 * @return True if there is at least one path between unitDef and unitUse on
 * which local l gets redefined, otherwise false
 */
private boolean isRedefined(Local l, Unit unitUse, AssignStmt unitDef, UnitGraph graph) {
    List<Unit> workList = new ArrayList<Unit>();
    workList.add(unitUse);
    Set<Unit> doneSet = new HashSet<Unit>();
    // Check for redefinitions of the local between definition and use
    while (!workList.isEmpty()) {
        Unit curStmt = workList.remove(0);
        if (!doneSet.add(curStmt))
            continue;
        for (Unit u : graph.getPredsOf(curStmt)) {
            if (u != unitDef) {
                if (u instanceof DefinitionStmt) {
                    DefinitionStmt defStmt = (DefinitionStmt) u;
                    if (defStmt.getLeftOp() == l)
                        return true;
                }
                workList.add(u);
            }
        }
    }
    return false;
}

Example 68 with Unit

use of soot.Unit in project soot by Sable.

the class DexArrayInitReducer method internalTransform.

@Override
protected void internalTransform(Body b, String phaseName, Map<String, String> options) {
    // Make sure that we only have linear control flow
    if (!b.getTraps().isEmpty())
        return;
    // Look for a chain of two constant assignments followed by an array put
    Unit u1 = null, u2 = null;
    for (Iterator<Unit> uIt = b.getUnits().snapshotIterator(); uIt.hasNext(); ) {
        Unit u = uIt.next();
        // If this is not an assignment, it does not matter.
        if (!(u instanceof AssignStmt) || !((Stmt) u).getBoxesPointingToThis().isEmpty()) {
            u1 = null;
            u2 = null;
            continue;
        }
        // If this is an assignment to an array, we must already have two
        // preceding constant assignments
        AssignStmt assignStmt = (AssignStmt) u;
        if (assignStmt.getLeftOp() instanceof ArrayRef) {
            if (u1 != null && u2 != null && u2.getBoxesPointingToThis().isEmpty() && assignStmt.getBoxesPointingToThis().isEmpty()) {
                ArrayRef arrayRef = (ArrayRef) assignStmt.getLeftOp();
                Value u1val = u1.getDefBoxes().get(0).getValue();
                Value u2val = u2.getDefBoxes().get(0).getValue();
                // index
                if (arrayRef.getIndex() == u1val)
                    arrayRef.setIndex(((AssignStmt) u1).getRightOp());
                else if (arrayRef.getIndex() == u2val)
                    arrayRef.setIndex(((AssignStmt) u2).getRightOp());
                // value
                if (assignStmt.getRightOp() == u1val)
                    assignStmt.setRightOp(((AssignStmt) u1).getRightOp());
                else if (assignStmt.getRightOp() == u2val)
                    assignStmt.setRightOp(((AssignStmt) u2).getRightOp());
                // Remove the unnecessary assignments
                Unit checkU = u;
                boolean foundU1 = false, foundU2 = false, doneU1 = false, doneU2 = false;
                while (!(doneU1 && doneU2) && !(foundU1 && foundU2) && checkU != null) {
                    // Does the current statement use the value?
                    for (ValueBox vb : checkU.getUseBoxes()) {
                        if (!doneU1 && vb.getValue() == u1val)
                            foundU1 = true;
                        if (!doneU2 && vb.getValue() == u2val)
                            foundU2 = true;
                    }
                    // Does the current statement overwrite the value?
                    for (ValueBox vb : checkU.getDefBoxes()) {
                        if (vb.getValue() == u1val)
                            doneU1 = true;
                        else if (vb.getValue() == u2val)
                            doneU2 = true;
                    }
                    // If this statement branches, we abort
                    if (checkU.branches()) {
                        foundU1 = true;
                        foundU2 = true;
                        break;
                    }
                    // Get the next statement
                    checkU = b.getUnits().getSuccOf(checkU);
                }
                if (!foundU1) {
                    // only remove constant assignment if the left value is Local
                    if (u1val instanceof Local) {
                        b.getUnits().remove(u1);
                        if (Options.v().verbose()) {
                            logger.debug("[" + b.getMethod().getName() + "]    remove 1 " + u1);
                        }
                    }
                }
                if (!foundU2) {
                    // only remove constant assignment if the left value is Local
                    if (u2val instanceof Local) {
                        b.getUnits().remove(u2);
                        if (Options.v().verbose()) {
                            logger.debug("[" + b.getMethod().getName() + "]    remove 2 " + u2);
                        }
                    }
                }
                u1 = null;
                u2 = null;
            } else {
                // No proper initialization before
                u1 = null;
                u2 = null;
                continue;
            }
        }
        // value.
        if (!(assignStmt.getRightOp() instanceof Constant)) {
            u1 = null;
            u2 = null;
            continue;
        }
        if (u1 == null) {
            u1 = assignStmt;
        } else if (u2 == null) {
            u2 = assignStmt;
            // If the last value is overwritten again, we start again at the beginning
            if (u1 != null) {
                Value op1 = ((AssignStmt) u1).getLeftOp();
                if (op1 == ((AssignStmt) u2).getLeftOp()) {
                    u1 = u2;
                    u2 = null;
                }
            }
        } else {
            u1 = u2;
            u2 = assignStmt;
        }
    }
    // Remove all locals that are no longer necessary
    UnusedLocalEliminator.v().transform(b);
}

Example 69 with Unit

use of soot.Unit in project soot by Sable.

the class DexPrinter method toMethodImplementation.

private MethodImplementation toMethodImplementation(SootMethod m) {
    if (m.isAbstract() || m.isNative()) {
        return null;
    }
    Body activeBody = m.retrieveActiveBody();
    // when installing the app
    if (m.getName().contains("<") || m.getName().equals(">"))
        if (!m.getName().equals("<init>") && !m.getName().equals("<clinit>"))
            throw new RuntimeException("Invalid method name: " + m.getName());
    // Switch statements may not be empty in dex, so we have to fix this
    // first
    EmptySwitchEliminator.v().transform(activeBody);
    // Dalvik requires synchronized methods to have explicit monitor calls,
    // so we insert them here. See
    // http://milk.com/kodebase/dalvik-docs-mirror/docs/debugger.html
    // We cannot place this upon the developer since it is only required
    // for Dalvik, but not for other targets.
    SynchronizedMethodTransformer.v().transform(activeBody);
    // Tries may not start or end at units which have no corresponding
    // Dalvik
    // instructions such as IdentityStmts. We reduce the traps to start at
    // the
    // first "real" instruction. We could also use a TrapTigthener, but that
    // would be too expensive for what we need here.
    FastDexTrapTightener.v().transform(activeBody);
    // Look for sequences of array element assignments that we can collapse
    // into bulk initializations
    DexArrayInitDetector initDetector = new DexArrayInitDetector();
    initDetector.constructArrayInitializations(activeBody);
    initDetector.fixTraps(activeBody);
    // Split the tries since Dalvik does not supported nested try/catch
    // blocks
    TrapSplitter.v().transform(activeBody);
    // word count of incoming parameters
    int inWords = SootToDexUtils.getDexWords(m.getParameterTypes());
    if (!m.isStatic()) {
        // extra word for "this"
        inWords++;
    }
    // word count of max outgoing parameters
    Collection<Unit> units = activeBody.getUnits();
    // register count = parameters + additional registers, depending on the
    // dex instructions generated (e.g. locals used and constants loaded)
    StmtVisitor stmtV = new StmtVisitor(m, initDetector);
    Chain<Trap> traps = activeBody.getTraps();
    Set<Unit> trapReferences = new HashSet<Unit>(traps.size() * 3);
    for (Trap t : activeBody.getTraps()) {
        trapReferences.add(t.getBeginUnit());
        trapReferences.add(t.getEndUnit());
        trapReferences.add(t.getHandlerUnit());
    }
    toInstructions(units, stmtV, trapReferences);
    int registerCount = stmtV.getRegisterCount();
    if (inWords > registerCount) {
        /*
			 * as the Dalvik VM moves the parameters into the last registers, the "in" word
			 * count must be at least equal to the register count. a smaller register count
			 * could occur if soot generated the method body, see e.g. the handling of
			 * phantom refs in SootMethodRefImpl.resolve(StringBuffer): the body has no
			 * locals for the ParameterRefs, it just throws an error.
			 *
			 * we satisfy the verifier by just increasing the register count, since calling
			 * phantom refs will lead to an error anyway.
			 */
        registerCount = inWords;
    }
    MethodImplementationBuilder builder = new MethodImplementationBuilder(registerCount);
    LabelAssigner labelAssinger = new LabelAssigner(builder);
    List<BuilderInstruction> instructions = stmtV.getRealInsns(labelAssinger);
    fixLongJumps(instructions, labelAssinger, stmtV);
    Map<Local, Integer> seenRegisters = new HashMap<Local, Integer>();
    Map<Instruction, LocalRegisterAssignmentInformation> instructionRegisterMap = stmtV.getInstructionRegisterMap();
    if (Options.v().write_local_annotations()) {
        for (LocalRegisterAssignmentInformation assignment : stmtV.getParameterInstructionsList()) {
            // (at least not if it exists with exactly this name)
            if (assignment.getLocal().getName().equals("this"))
                continue;
            addRegisterAssignmentDebugInfo(assignment, seenRegisters, builder);
        }
    }
    for (BuilderInstruction ins : instructions) {
        Stmt origStmt = stmtV.getStmtForInstruction(ins);
        // If this is a switch payload, we need to place the label
        if (stmtV.getInstructionPayloadMap().containsKey(ins))
            builder.addLabel(labelAssinger.getLabelName(stmtV.getInstructionPayloadMap().get(ins)));
        if (origStmt != null) {
            // Do we need a label here because this a trap handler?
            if (trapReferences.contains(origStmt))
                labelAssinger.getOrCreateLabel(origStmt);
            // Add the label if the statement has one
            String labelName = labelAssinger.getLabelName(origStmt);
            if (labelName != null && !builder.getLabel(labelName).isPlaced())
                builder.addLabel(labelName);
            // Add the tags
            if (stmtV.getStmtForInstruction(ins) != null) {
                List<Tag> tags = origStmt.getTags();
                for (Tag t : tags) {
                    if (t instanceof LineNumberTag) {
                        LineNumberTag lnt = (LineNumberTag) t;
                        builder.addLineNumber(lnt.getLineNumber());
                    } else if (t instanceof SourceFileTag) {
                        SourceFileTag sft = (SourceFileTag) t;
                        builder.addSetSourceFile(new ImmutableStringReference(sft.getSourceFile()));
                    }
                }
            }
        }
        builder.addInstruction(ins);
        LocalRegisterAssignmentInformation registerAssignmentTag = instructionRegisterMap.get(ins);
        if (registerAssignmentTag != null) {
            // Add start local debugging information: Register -> Local
            // assignment
            addRegisterAssignmentDebugInfo(registerAssignmentTag, seenRegisters, builder);
        }
    }
    for (int registersLeft : seenRegisters.values()) builder.addEndLocal(registersLeft);
    toTries(activeBody.getTraps(), stmtV, builder, labelAssinger);
    // Make sure that all labels have been placed by now
    for (Label lbl : labelAssinger.getAllLabels()) if (!lbl.isPlaced())
        throw new RuntimeException("Label not placed: " + lbl);
    return builder.getMethodImplementation();
}

Example 70 with Unit

use of soot.Unit in project soot by Sable.

the class FastDexTrapTightener method internalTransform.

@Override
protected void internalTransform(Body b, String phaseName, Map<String, String> options) {
    for (Iterator<Trap> trapIt = b.getTraps().snapshotIterator(); trapIt.hasNext(); ) {
        Trap t = trapIt.next();
        Unit beginUnit;
        while (!isDexInstruction(beginUnit = t.getBeginUnit()) && t.getBeginUnit() != t.getEndUnit()) t.setBeginUnit(b.getUnits().getSuccOf(beginUnit));
        // If the trap is empty, we remove it
        if (t.getBeginUnit() == t.getEndUnit())
            trapIt.remove();
    }
}