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[analyzer][UninitializedObjectChecker] Void pointers are casted back to their dynamic type in note message 

Differential Revision: https://reviews.llvm.org/D49228

llvm-svn: 339653
This commit is contained in:
Kristof Umann 2018-08-14 08:20:51 +00:00
parent 5d94b25ffe
commit 5a42441d81
2 changed files with 46 additions and 8 deletions
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42
clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp
View File

@ -60,6 +60,32 @@ public:
}
};
/// Represents a void* field that needs to be casted back to its dynamic type
/// for a correct note message.
class NeedsCastLocField final : public FieldNode {
QualType CastBackType;
public:
NeedsCastLocField(const FieldRegion *FR, const QualType &T)
: FieldNode(FR), CastBackType(T) {}
virtual void printNoteMsg(llvm::raw_ostream &Out) const override {
Out << "uninitialized pointee ";
}
virtual void printPrefix(llvm::raw_ostream &Out) const override {
Out << "static_cast" << '<' << CastBackType.getAsString() << ">(";
}
virtual void printNode(llvm::raw_ostream &Out) const override {
Out << getVariableName(getDecl()) << ')';
}
virtual void printSeparator(llvm::raw_ostream &Out) const override {
Out << "->";
}
};
} // end of anonymous namespace
// Utility function declarations.
@ -122,6 +148,10 @@ bool FindUninitializedFields::isPointerOrReferenceUninit(
QualType DynT = DynTInfo.getType();
// If the static type of the field is a void pointer, we need to cast it back
// to the dynamic type before dereferencing.
bool NeedsCastBack = isVoidPointer(FR->getDecl()->getType());
if (isVoidPointer(DynT)) {
IsAnyFieldInitialized = true;
return false;
@ -160,11 +190,16 @@ bool FindUninitializedFields::isPointerOrReferenceUninit(
const TypedValueRegion *R = RecordV->getRegion();
if (DynT->getPointeeType()->isStructureOrClassType())
if (DynT->getPointeeType()->isStructureOrClassType()) {
if (NeedsCastBack)
return isNonUnionUninit(R, LocalChain.add(NeedsCastLocField(FR, DynT)));
return isNonUnionUninit(R, LocalChain.add(LocField(FR)));
}
if (DynT->getPointeeType()->isUnionType()) {
if (isUnionUninit(R)) {
if (NeedsCastBack)
return addFieldToUninits(LocalChain.add(NeedsCastLocField(FR, DynT)));
return addFieldToUninits(LocalChain.add(LocField(FR)));
} else {
IsAnyFieldInitialized = true;
@ -185,8 +220,11 @@ bool FindUninitializedFields::isPointerOrReferenceUninit(
"At this point FR must either have a primitive dynamic type, or it "
"must be a null, undefined, unknown or concrete pointer!");
if (isPrimitiveUninit(DerefdV))
if (isPrimitiveUninit(DerefdV)) {
if (NeedsCastBack)
return addFieldToUninits(LocalChain.add(NeedsCastLocField(FR, DynT)));
return addFieldToUninits(LocalChain.add(LocField(FR)));
}
IsAnyFieldInitialized = true;
return false;

12
clang/test/Analysis/cxx-uninitialized-object-ptr-ref.cpp
View File

@ -292,7 +292,7 @@ void fCyclicVoidPointerTest() {
}
struct IntDynTypedVoidPointerTest1 {
void *vptr; // expected-note{{uninitialized pointee 'this->vptr'}}
void *vptr; // expected-note{{uninitialized pointee 'static_cast<int *>(this->vptr)'}}
int dontGetFilteredByNonPedanticMode = 0;
IntDynTypedVoidPointerTest1(void *vptr) : vptr(vptr) {} // expected-warning{{1 uninitialized field}}
@ -305,8 +305,8 @@ void fIntDynTypedVoidPointerTest1() {
struct RecordDynTypedVoidPointerTest {
struct RecordType {
int x; // expected-note{{uninitialized field 'this->vptr->x'}}
int y; // expected-note{{uninitialized field 'this->vptr->y'}}
int x; // expected-note{{uninitialized field 'static_cast<struct RecordDynTypedVoidPointerTest::RecordType *>(this->vptr)->x'}}
int y; // expected-note{{uninitialized field 'static_cast<struct RecordDynTypedVoidPointerTest::RecordType *>(this->vptr)->y'}}
};
void *vptr;
@ -322,9 +322,9 @@ void fRecordDynTypedVoidPointerTest() {
struct NestedNonVoidDynTypedVoidPointerTest {
struct RecordType {
int x; // expected-note{{uninitialized field 'this->vptr->x'}}
int y; // expected-note{{uninitialized field 'this->vptr->y'}}
void *vptr; // expected-note{{uninitialized pointee 'this->vptr->vptr'}}
int x; // expected-note{{uninitialized field 'static_cast<struct NestedNonVoidDynTypedVoidPointerTest::RecordType *>(this->vptr)->x'}}
int y; // expected-note{{uninitialized field 'static_cast<struct NestedNonVoidDynTypedVoidPointerTest::RecordType *>(this->vptr)->y'}}
void *vptr; // expected-note{{uninitialized pointee 'static_cast<char *>(static_cast<struct NestedNonVoidDynTypedVoidPointerTest::RecordType *>(this->vptr)->vptr)'}}
};
void *vptr;