New static analyzer check by Nikita Zhuk!
"The attached patch generates warnings of cases where an ObjC message is sent to
a nil object and the size of return type of that message is larger than the size
of void pointer. This may result in undefined return values as described in PR
2718. The patch also includes test cases."
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68585 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/GRExprEngine.cpp b/lib/Analysis/GRExprEngine.cpp
index 487aac0..06d61cc 100644
--- a/lib/Analysis/GRExprEngine.cpp
+++ b/lib/Analysis/GRExprEngine.cpp
@@ -1690,20 +1690,40 @@
if (isFeasibleNull) {
// Check if the receiver was nil and the return value a struct.
- if (ME->getType()->isRecordType() &&
- BR.getParentMap().isConsumedExpr(ME)) {
- // The [0 ...] expressions will return garbage. Flag either an
- // explicit or implicit error. Because of the structure of this
- // function we currently do not bifurfacte the state graph at
- // this point.
- // FIXME: We should bifurcate and fill the returned struct with
- // garbage.
- if (NodeTy* N = Builder->generateNode(ME, StNull, Pred)) {
- N->markAsSink();
- if (isFeasibleNotNull)
- NilReceiverStructRetImplicit.insert(N);
- else
- NilReceiverStructRetExplicit.insert(N);
+ if (BR.getParentMap().isConsumedExpr(ME)) {
+ if(ME->getType()->isRecordType()) {
+ // The [0 ...] expressions will return garbage. Flag either an
+ // explicit or implicit error. Because of the structure of this
+ // function we currently do not bifurfacte the state graph at
+ // this point.
+ // FIXME: We should bifurcate and fill the returned struct with
+ // garbage.
+ if (NodeTy* N = Builder->generateNode(ME, StNull, Pred)) {
+ N->markAsSink();
+ if (isFeasibleNotNull)
+ NilReceiverStructRetImplicit.insert(N);
+ else
+ NilReceiverStructRetExplicit.insert(N);
+ }
+ }
+ else {
+ ASTContext& Ctx = getContext();
+
+ // sizeof(void *)
+ const uint64_t voidPtrSize = Ctx.getTypeSize(Ctx.VoidPtrTy);
+
+ // sizeof(return type)
+ const uint64_t returnTypeSize = Ctx.getTypeSize(ME->getType());
+
+ if(voidPtrSize < returnTypeSize) {
+ if (NodeTy* N = Builder->generateNode(ME, StNull, Pred)) {
+ N->markAsSink();
+ if(isFeasibleNotNull)
+ NilReceiverLargerThanVoidPtrRetImplicit.insert(N);
+ else
+ NilReceiverLargerThanVoidPtrRetExplicit.insert(N);
+ }
+ }
}
}
}
diff --git a/lib/Analysis/GRExprEngineInternalChecks.cpp b/lib/Analysis/GRExprEngineInternalChecks.cpp
index 45baebd..f4efdb1 100644
--- a/lib/Analysis/GRExprEngineInternalChecks.cpp
+++ b/lib/Analysis/GRExprEngineInternalChecks.cpp
@@ -98,6 +98,37 @@
}
}
};
+
+class VISIBILITY_HIDDEN NilReceiverLargerThanVoidPtrRet : public BugType {
+ GRExprEngine &Eng;
+public:
+ NilReceiverLargerThanVoidPtrRet(GRExprEngine* eng) :
+ BugType("'nil' receiver with return type larger than sizeof(void *)",
+ "Logic Errors"),
+ Eng(*eng) {}
+
+ void FlushReports(BugReporter& BR) {
+ for (GRExprEngine::nil_receiver_larger_than_voidptr_ret_iterator
+ I=Eng.nil_receiver_larger_than_voidptr_ret_begin(),
+ E=Eng.nil_receiver_larger_than_voidptr_ret_end(); I!=E; ++I) {
+
+ std::string sbuf;
+ llvm::raw_string_ostream os(sbuf);
+ PostStmt P = cast<PostStmt>((*I)->getLocation());
+ ObjCMessageExpr *ME = cast<ObjCMessageExpr>(P.getStmt());
+ os << "The receiver in the message expression is 'nil' and results in the"
+ " returned value (of type '"
+ << ME->getType().getAsString()
+ << "' and of size "
+ << Eng.getContext().getTypeSize(ME->getType()) / 8
+ << " bytes) to be garbage or otherwise undefined.";
+
+ RangedBugReport *R = new RangedBugReport(*this, os.str().c_str(), *I);
+ R->addRange(ME->getReceiver()->getSourceRange());
+ BR.EmitReport(R);
+ }
+ }
+};
class VISIBILITY_HIDDEN UndefinedDeref : public BuiltinBug {
public:
@@ -465,6 +496,7 @@
BR.Register(new OutOfBoundMemoryAccess(this));
BR.Register(new BadSizeVLA(this));
BR.Register(new NilReceiverStructRet(this));
+ BR.Register(new NilReceiverLargerThanVoidPtrRet(this));
// The following checks do not need to have their associated BugTypes
// explicitly registered with the BugReporter. If they issue any BugReports,