Examples with Unit soot.Unit used on opensource projects

Example 61 with Unit

use of soot.Unit in project soot by Sable.

the class Util method addExceptionAfterUnit.

/**
 * Insert a runtime exception before unit u of body b. Useful to analyze
 * broken code (which make reference to inexisting class for instance)
 * exceptionType: e.g., "java.lang.RuntimeException"
 */
public static void addExceptionAfterUnit(Body b, String exceptionType, Unit u, String m) {
    LocalCreation lc = new LocalCreation(b.getLocals());
    Local l = lc.newLocal(RefType.v(exceptionType));
    List<Unit> newUnits = new ArrayList<Unit>();
    Unit u1 = Jimple.v().newAssignStmt(l, Jimple.v().newNewExpr(RefType.v(exceptionType)));
    Unit u2 = Jimple.v().newInvokeStmt(Jimple.v().newSpecialInvokeExpr(l, Scene.v().makeMethodRef(Scene.v().getSootClass(exceptionType), "<init>", Collections.singletonList((Type) RefType.v("java.lang.String")), VoidType.v(), false), StringConstant.v(m)));
    Unit u3 = Jimple.v().newThrowStmt(l);
    newUnits.add(u1);
    newUnits.add(u2);
    newUnits.add(u3);
    b.getUnits().insertBefore(newUnits, u);
}

Example 62 with Unit

use of soot.Unit in project soot by Sable.

the class DexDefUseAnalysis method getDefsOf.

@Override
public List<Unit> getDefsOf(Local l) {
    Set<Unit> defs = localToDefs.get(l);
    if (defs == null) {
        defs = new HashSet<>();
        BitSet bs = localToDefsBits[localToNumber.get(l)];
        if (bs != null) {
            for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i + 1)) {
                Unit u = unitList.get(i);
                if (u instanceof DefinitionStmt)
                    if (((DefinitionStmt) u).getLeftOp() == l)
                        defs.add(u);
            }
        }
        localToDefs.put(l, defs);
    }
    return new ArrayList<>(defs);
}

Example 63 with Unit

use of soot.Unit in project soot by Sable.

the class DexDefUseAnalysis method getUsesOf.

public Set<Unit> getUsesOf(Local l) {
    Set<Unit> uses = localToUses.get(l);
    if (uses == null) {
        uses = new HashSet<>();
        BitSet bs = localToUsesBits[localToNumber.get(l)];
        if (bs != null) {
            for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i + 1)) {
                uses.add(unitList.get(i));
            }
        }
        localToUses.put(l, uses);
    }
    return uses;
}

Example 64 with Unit

use of soot.Unit in project soot by Sable.

the class DexNullTransformer method internalTransform.

@Override
protected void internalTransform(final Body body, String phaseName, Map<String, String> options) {
    final DexDefUseAnalysis localDefs = new DexDefUseAnalysis(body);
    AbstractStmtSwitch checkDef = new // Alex: should also end as
    AbstractStmtSwitch() {

        // soon as detected as not
        // used as an object
        @Override
        public void caseAssignStmt(AssignStmt stmt) {
            Value r = stmt.getRightOp();
            if (r instanceof FieldRef) {
                usedAsObject = isObject(((FieldRef) r).getFieldRef().type());
                doBreak = true;
                return;
            } else if (r instanceof ArrayRef) {
                ArrayRef ar = (ArrayRef) r;
                if (ar.getType() instanceof UnknownType) {
                    // isObject
                    usedAsObject = stmt.hasTag("ObjectOpTag");
                // (findArrayType
                // (g,
                // localDefs,
                // localUses,
                // stmt));
                } else {
                    usedAsObject = isObject(ar.getType());
                }
                doBreak = true;
                return;
            } else if (r instanceof StringConstant || r instanceof NewExpr || r instanceof NewArrayExpr) {
                usedAsObject = true;
                doBreak = true;
                return;
            } else if (r instanceof CastExpr) {
                usedAsObject = isObject(((CastExpr) r).getCastType());
                doBreak = true;
                return;
            } else if (r instanceof InvokeExpr) {
                usedAsObject = isObject(((InvokeExpr) r).getType());
                doBreak = true;
                return;
            } else if (r instanceof LengthExpr) {
                usedAsObject = false;
                doBreak = true;
                return;
            // introduces alias
            }
        }

        @Override
        public void caseIdentityStmt(IdentityStmt stmt) {
            if (stmt.getLeftOp() == l) {
                usedAsObject = isObject(stmt.getRightOp().getType());
                doBreak = true;
                return;
            }
        }
    };
    AbstractStmtSwitch checkUse = new AbstractStmtSwitch() {

        private boolean examineInvokeExpr(InvokeExpr e) {
            List<Value> args = e.getArgs();
            List<Type> argTypes = e.getMethodRef().parameterTypes();
            assert args.size() == argTypes.size();
            for (int i = 0; i < args.size(); i++) {
                if (args.get(i) == l && isObject(argTypes.get(i))) {
                    return true;
                }
            }
            // check for base
            SootMethodRef sm = e.getMethodRef();
            if (!sm.isStatic()) {
                if (e instanceof AbstractInvokeExpr) {
                    AbstractInstanceInvokeExpr aiiexpr = (AbstractInstanceInvokeExpr) e;
                    Value b = aiiexpr.getBase();
                    if (b == l) {
                        return true;
                    }
                }
            }
            return false;
        }

        @Override
        public void caseInvokeStmt(InvokeStmt stmt) {
            InvokeExpr e = stmt.getInvokeExpr();
            usedAsObject = examineInvokeExpr(e);
            doBreak = true;
            return;
        }

        @Override
        public void caseAssignStmt(AssignStmt stmt) {
            Value left = stmt.getLeftOp();
            Value r = stmt.getRightOp();
            if (left instanceof ArrayRef) {
                ArrayRef ar = (ArrayRef) left;
                if (ar.getIndex() == l) {
                    doBreak = true;
                    return;
                } else if (ar.getBase() == l) {
                    usedAsObject = true;
                    doBreak = true;
                    return;
                }
            }
            if (left instanceof InstanceFieldRef) {
                InstanceFieldRef ifr = (InstanceFieldRef) left;
                if (ifr.getBase() == l) {
                    usedAsObject = true;
                    doBreak = true;
                    return;
                }
            }
            // used to assign
            if (stmt.getRightOp() == l) {
                Value l = stmt.getLeftOp();
                if (l instanceof StaticFieldRef && isObject(((StaticFieldRef) l).getFieldRef().type())) {
                    usedAsObject = true;
                    doBreak = true;
                    return;
                } else if (l instanceof InstanceFieldRef && isObject(((InstanceFieldRef) l).getFieldRef().type())) {
                    usedAsObject = true;
                    doBreak = true;
                    return;
                } else if (l instanceof ArrayRef) {
                    Type aType = ((ArrayRef) l).getType();
                    if (aType instanceof UnknownType) {
                        usedAsObject = stmt.hasTag(// isObject(
                        "ObjectOpTag");
                    // findArrayType(g,
                    // localDefs,
                    // localUses,
                    // stmt));
                    } else {
                        usedAsObject = isObject(aType);
                    }
                    doBreak = true;
                    return;
                }
            }
            // is used as value (does not exclude assignment)
            if (r instanceof FieldRef) {
                // isObject(((FieldRef)
                usedAsObject = true;
                // r).getFieldRef().type());
                doBreak = true;
                return;
            } else if (r instanceof ArrayRef) {
                ArrayRef ar = (ArrayRef) r;
                if (ar.getBase() == l) {
                    usedAsObject = true;
                } else {
                    // used as index
                    usedAsObject = false;
                }
                doBreak = true;
                return;
            } else if (r instanceof StringConstant || r instanceof NewExpr) {
                throw new RuntimeException("NOT POSSIBLE StringConstant or NewExpr at " + stmt);
            } else if (r instanceof NewArrayExpr) {
                usedAsObject = false;
                doBreak = true;
                return;
            } else if (r instanceof CastExpr) {
                usedAsObject = isObject(((CastExpr) r).getCastType());
                doBreak = true;
                return;
            } else if (r instanceof InvokeExpr) {
                usedAsObject = examineInvokeExpr((InvokeExpr) stmt.getRightOp());
                doBreak = true;
                return;
            } else if (r instanceof LengthExpr) {
                usedAsObject = true;
                doBreak = true;
                return;
            } else if (r instanceof BinopExpr) {
                usedAsObject = false;
                doBreak = true;
                return;
            }
        }

        @Override
        public void caseIdentityStmt(IdentityStmt stmt) {
            if (stmt.getLeftOp() == l)
                throw new RuntimeException("IMPOSSIBLE 0");
        }

        @Override
        public void caseEnterMonitorStmt(EnterMonitorStmt stmt) {
            usedAsObject = stmt.getOp() == l;
            doBreak = true;
            return;
        }

        @Override
        public void caseExitMonitorStmt(ExitMonitorStmt stmt) {
            usedAsObject = stmt.getOp() == l;
            doBreak = true;
            return;
        }

        @Override
        public void caseReturnStmt(ReturnStmt stmt) {
            usedAsObject = stmt.getOp() == l && isObject(body.getMethod().getReturnType());
            doBreak = true;
            return;
        }

        @Override
        public void caseThrowStmt(ThrowStmt stmt) {
            usedAsObject = stmt.getOp() == l;
            doBreak = true;
            return;
        }
    };
    for (Local loc : getNullCandidates(body)) {
        usedAsObject = false;
        Set<Unit> defs = localDefs.collectDefinitionsWithAliases(loc);
        // process normally
        doBreak = false;
        for (Unit u : defs) {
            // put correct local in l
            if (u instanceof DefinitionStmt) {
                l = (Local) ((DefinitionStmt) u).getLeftOp();
            } else if (u instanceof IfStmt) {
                throw new RuntimeException("ERROR: def can not be something else than Assign or Identity statement! (def: " + u + " class: " + u.getClass() + "");
            }
            // check defs
            u.apply(checkDef);
            if (doBreak)
                break;
            // check uses
            for (Unit use : localDefs.getUsesOf(l)) {
                use.apply(checkUse);
                if (doBreak)
                    break;
            }
            // for uses
            if (doBreak)
                break;
        }
        // change values
        if (usedAsObject) {
            for (Unit u : defs) {
                replaceWithNull(u);
                Set<Value> defLocals = new HashSet<Value>();
                for (ValueBox vb : u.getDefBoxes()) defLocals.add(vb.getValue());
                Local l = (Local) ((DefinitionStmt) u).getLeftOp();
                for (Unit uuse : localDefs.getUsesOf(l)) {
                    Stmt use = (Stmt) uuse;
                    // If we have a[x] = 0 and a is an object, we may not conclude 0 -> null
                    if (!use.containsArrayRef() || !defLocals.contains(use.getArrayRef().getBase()))
                        replaceWithNull(use);
                }
            }
        }
    // end if
    }
    // Check for inlined zero values
    AbstractStmtSwitch inlinedZeroValues = new AbstractStmtSwitch() {

        final NullConstant nullConstant = NullConstant.v();

        @Override
        public void caseAssignStmt(AssignStmt stmt) {
            // Case a = 0 with a being an object
            if (isObject(stmt.getLeftOp().getType()) && isConstZero(stmt.getRightOp())) {
                stmt.setRightOp(nullConstant);
                return;
            }
            // Case a = (Object) 0
            if (stmt.getRightOp() instanceof CastExpr) {
                CastExpr ce = (CastExpr) stmt.getRightOp();
                if (isObject(ce.getCastType()) && isConstZero(ce.getOp())) {
                    stmt.setRightOp(nullConstant);
                }
            }
            // Case a[0] = 0
            if (stmt.getLeftOp() instanceof ArrayRef && isConstZero(stmt.getRightOp())) {
                ArrayRef ar = (ArrayRef) stmt.getLeftOp();
                if (isObjectArray(ar.getBase(), body) || stmt.hasTag("ObjectOpTag")) {
                    stmt.setRightOp(nullConstant);
                }
            }
        }

        private boolean isConstZero(Value rightOp) {
            if (rightOp instanceof IntConstant && ((IntConstant) rightOp).value == 0)
                return true;
            if (rightOp instanceof LongConstant && ((LongConstant) rightOp).value == 0)
                return true;
            return false;
        }

        @Override
        public void caseReturnStmt(ReturnStmt stmt) {
            if (stmt.getOp() instanceof IntConstant && isObject(body.getMethod().getReturnType())) {
                IntConstant iconst = (IntConstant) stmt.getOp();
                assert iconst.value == 0;
                stmt.setOp(nullConstant);
            }
        }

        @Override
        public void caseEnterMonitorStmt(EnterMonitorStmt stmt) {
            if (stmt.getOp() instanceof IntConstant && ((IntConstant) stmt.getOp()).value == 0)
                stmt.setOp(nullConstant);
        }

        @Override
        public void caseExitMonitorStmt(ExitMonitorStmt stmt) {
            if (stmt.getOp() instanceof IntConstant && ((IntConstant) stmt.getOp()).value == 0)
                stmt.setOp(nullConstant);
        }
    };
    final NullConstant nullConstant = NullConstant.v();
    for (Unit u : body.getUnits()) {
        u.apply(inlinedZeroValues);
        if (u instanceof Stmt) {
            Stmt stmt = (Stmt) u;
            if (stmt.containsInvokeExpr()) {
                InvokeExpr invExpr = stmt.getInvokeExpr();
                for (int i = 0; i < invExpr.getArgCount(); i++) if (isObject(invExpr.getMethodRef().parameterType(i)))
                    if (invExpr.getArg(i) instanceof IntConstant) {
                        IntConstant iconst = (IntConstant) invExpr.getArg(i);
                        assert iconst.value == 0;
                        invExpr.setArg(i, nullConstant);
                    }
            }
        }
    }
}

Example 65 with Unit

use of soot.Unit in project soot by Sable.

the class DexNullTransformer method getNullCandidates.

/**
 * Collect all the locals which are assigned a IntConstant(0) or are used
 * within a zero comparison.
 *
 * @param body
 *            the body to analyze
 */
private Set<Local> getNullCandidates(Body body) {
    Set<Local> candidates = null;
    for (Unit u : body.getUnits()) {
        if (u instanceof AssignStmt) {
            AssignStmt a = (AssignStmt) u;
            if (!(a.getLeftOp() instanceof Local))
                continue;
            Local l = (Local) a.getLeftOp();
            Value r = a.getRightOp();
            if ((r instanceof IntConstant && ((IntConstant) r).value == 0) || (r instanceof LongConstant && ((LongConstant) r).value == 0)) {
                if (candidates == null)
                    candidates = new HashSet<Local>();
                candidates.add(l);
            }
        } else if (u instanceof IfStmt) {
            ConditionExpr expr = (ConditionExpr) ((IfStmt) u).getCondition();
            if (isZeroComparison(expr) && expr.getOp1() instanceof Local) {
                if (candidates == null)
                    candidates = new HashSet<Local>();
                candidates.add((Local) expr.getOp1());
            }
        }
    }
    return candidates == null ? Collections.<Local>emptySet() : candidates;
}