/* * Copyright (c) 2016 - present Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD style license found in the * LICENSE file in the root directory of this source tree. An additional grant * of patent rights can be found in the PATENTS file in the same directory. */ package codetoanalyze.java.checkers; import javax.annotation.concurrent.ThreadSafe; import javax.inject.Inject; import javax.inject.Provider; class Obj { Object f; Obj g; } interface CustomProvider extends Provider { @Override public T get(); } @ThreadSafe public class Ownership { Obj field; public Ownership(Obj o) { field = o; } // understand that ownership can be acquired via DI @Inject Ownership(Provider objProvider) { Obj owned = objProvider.get(); owned.f = new Object(); // should not report } @Inject Ownership(CustomProvider objProvider) { Obj owned = objProvider.get(); owned.f = new Object(); // should not report } native void leakToAnotherThread(Object o); public void escapeViaConstructorBad() { Obj local = new Obj(); Ownership constructed = new Ownership(local); local.f = new Object(); } public void ownInOneBranchBad(Obj formal, boolean b) { if (b) { formal = new Obj(); } // we might not own formal formal.f = new Object(); } public void reassignToFormalBad(Obj formal) { Obj local = new Obj(); formal.g = local; // bad, we don't own formal formal.g.f = new Object(); // ok; now that formal.g is reassigned to local, which we do own } public void ownedLocalOk() { Obj local = new Obj(); local.f = new Object(); } public Obj returnOwnedLocalOk() { Obj local = new Obj(); local.f = new Object(); return local; } public void writeOwnedLocalThenEscapeOk() { Obj local = new Obj(); local.f = new Object(); leakToAnotherThread(local); } public void ownInBranchesOk1(boolean b) { Obj local; if (b) { local = new Obj(); local.f = new Object(); } else { local = new Obj(); local.f = new Integer(0); } local.f = new Boolean(false); } public void ownedAccessPathOk() { Obj local = new Obj(); local.g = new Obj(); local.g.f = new Object(); } public void aliasOwnedLocalOk() { Obj local = new Obj(); Obj alias = local; alias.f = new Object(); local.f = new Object(); } public void aliasOwnedLocalAccessPathOk() { Obj local = new Obj(); local.g = new Obj(); Obj alias = local.g; alias.f = new Object(); } private void writeToFormal(Obj formal) { formal.f = new Object(); } private void callWriteToFormal(Obj formal) { writeToFormal(formal); } private void setField(Obj o) { this.field = o; } native Obj getMaybeUnownedObj(); // warn here even though this this is safe if `o` is owned at all call sites. because it's a // public method, it's possible to use it in an unsafe way public void writeToNotOwnedInCalleeBad1(Obj o) { writeToFormal(o); } public void writeToNotOwnedInCalleeBad2() { Obj o = getMaybeUnownedObj(); writeToFormal(o); } public void writeToNotOwnedInCalleeBad3(Obj o) { callWriteToFormal(o); } // assuming that we can't own the `this` object public void cantOwnThisBad() { setField(new Obj()); } public void writeToOwnedInCalleeOk1() { Obj o = new Obj(); writeToFormal(o); } public void writeToOwnedInCalleeOk2() { synchronized (this) { this.field = new Obj(); } writeToFormal(this.field); } public void writeToOwnedInCalleeIndirectOk1() { Obj o = new Obj(); callWriteToFormal(o); } public void writeToOwnedInCalleeIndirectOk2() { Obj o = new Obj(); o.g = new Obj(); callWriteToFormal(o.g); } public Obj ownershipCanBeInterproceduralOk() { Obj local = returnOwnedLocalOk(); local.f = new Object(); return local; } public void mutateDoubleReturnOwnedOk() { Obj owned = ownershipCanBeInterproceduralOk(); owned.g = new Obj(); } Obj returnOwnedOrNull(boolean b) { if (b) { return null; } return new Obj(); } public void mutateAfterNullCheckOK(boolean b) { Obj o = returnOwnedOrNull(b); if (o != null) { o.f = new Object(); } } private void mutateIfNotNull(Obj o) { if (o != null) { o.f = new Object(); } } public void ownInCalleeViaNullOk() { mutateIfNotNull(null); } public void notOwnedInCalleeBad(Obj o) { mutateIfNotNull(o); } Obj id(Obj param) { return param; } public void passOwnershipInIdFunctionOk() { Obj owned = new Obj(); Obj shouldBeOwned = id(owned); shouldBeOwned.f = new Object(); } Obj id2(Obj param) { return id(param); } public void passOwnershipInMultiLevelIdFunctionOk() { Obj owned = new Obj(); Obj shouldBeOwned = id2(owned); shouldBeOwned.f = new Object(); } native boolean nondet(); public Obj returnConditionalOwnedInTwoBranches(Obj param) { if (nondet()) { return param; } return param; } public void returnConditionalOwnedInTwoBranchesOk() { Obj owned = new Obj(); Obj shouldBeOwned = returnConditionalOwnedInTwoBranches(owned); shouldBeOwned.f = new Object(); } public Obj returnOwnedOrConditionalOwned(Obj param) { if (nondet()) { return param; } else { return new Obj(); } } public void ownedAfterCastOk() { Object o = new Obj(); Obj owned = (Obj) o; owned.f = new Object(); } // TODO: need to handle multiple ownership attributes in order to get this one public void FP_ownAndConditionalOwnOk() { Obj owned = new Obj(); Obj shouldBeOwned = returnOwnedOrConditionalOwned(owned); shouldBeOwned.f = new Object(); } public Obj twoDifferentConditionalOwns(Obj param1, Obj param2) { if (nondet()) { return param1; } else { return param2; } } public void threadLocalOk(ThreadLocal threadLocal) { threadLocal.get().f = new Object(); } // need to handle multiple ownership attributes in order to get this one public void FP_twoDifferentConditionalOwnsOk() { Obj owned1 = new Obj(); Obj owned2 = new Obj(); Obj shouldBeOwned = twoDifferentConditionalOwns(owned1, owned2); shouldBeOwned.f = new Object(); } // we angelically assume that callees don't leak their arguments to another thread for now, so // we'll miss this public void FN_escapeThenWriteLocalBad() { Obj local = new Obj(); leakToAnotherThread(local); local.f = new Object(); } private Obj leakThenReturn() { Obj local = new Obj(); leakToAnotherThread(local); return local; } // the summary for leakThenReturn should not say that the caller owns the return value public void FN_mutateReturnedBad() { Obj notOwned = leakThenReturn(); notOwned.f = new Object(); // should warn here } private void castThenCall(Obj o) { Subclass s = (Subclass) o; s.doWrite(); } void castThenCallOk() { Obj o = new Obj(); castThenCall(o); } void castThenCallBad() { Obj o = getMaybeUnownedObj(); castThenCall(o); } private Obj castThenReturn(Obj o) { Subclass s = (Subclass) o; return s; } void castThenReturnOk() { Obj o = new Obj(); castThenReturn(o).f = new Object(); } void castThenReturnBad() { Obj o = getMaybeUnownedObj(); castThenReturn(o).f = new Object(); } } class Subclass extends Obj { public void doWrite() { f = new Object(); } }