/// Warns on methods overridden in DerivedDecl with respect to BaseDecl.
/// FIXME: this warns on all overrides outside of the sliced path in case of
/// multiple inheritance.
void SlicingCheck::DiagnoseSlicedOverriddenMethods(
const Expr &Call, const CXXRecordDecl &DerivedDecl,
const CXXRecordDecl &BaseDecl) {
if (DerivedDecl.getCanonicalDecl() == BaseDecl.getCanonicalDecl())
return;
for (const auto &Method : DerivedDecl.methods()) {
// Virtual destructors are OK. We're ignoring constructors since they are
// tagged as overrides.
if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
continue;
if (Method->size_overridden_methods() > 0) {
diag(Call.getExprLoc(),
"slicing object from type %0 to %1 discards override %2")
<< &DerivedDecl << &BaseDecl << Method;
}
}
// Recursively process bases.
for (const auto &Base : DerivedDecl.bases()) {
if (const auto *BaseRecordType = Base.getType()->getAs<RecordType>()) {
if (const auto *BaseRecord = cast_or_null<CXXRecordDecl>(
BaseRecordType->getDecl()->getDefinition()))
DiagnoseSlicedOverriddenMethods(Call, *BaseRecord, BaseDecl);
}
}
}
void MustOverrideChecker::check(const MatchFinder::MatchResult &Result) {
auto D = Result.Nodes.getNodeAs<CXXRecordDecl>("class");
// Look through all of our immediate bases to find methods that need to be
// overridden
typedef std::vector<CXXMethodDecl *> OverridesVector;
OverridesVector MustOverrides;
for (const auto &Base : D->bases()) {
// The base is either a class (CXXRecordDecl) or it's a templated class...
CXXRecordDecl *Parent = Base.getType()
.getDesugaredType(D->getASTContext())
->getAsCXXRecordDecl();
// The parent might not be resolved to a type yet. In this case, we can't
// do any checking here. For complete correctness, we should visit
// template instantiations, but this case is likely to be rare, so we will
// ignore it until it becomes important.
if (!Parent) {
continue;
}
Parent = Parent->getDefinition();
for (const auto &M : Parent->methods()) {
if (hasCustomAnnotation(M, "moz_must_override"))
MustOverrides.push_back(M);
}
}
for (auto &O : MustOverrides) {
bool Overridden = false;
for (const auto &M : D->methods()) {
// The way that Clang checks if a method M overrides its parent method
// is if the method has the same name but would not overload.
if (getNameChecked(M) == getNameChecked(O) &&
!CI->getSema().IsOverload(M, O, false)) {
Overridden = true;
break;
}
}
if (!Overridden) {
diag(D->getLocation(), "%0 must override %1", DiagnosticIDs::Error)
<< D->getDeclName() << O->getDeclName();
diag(O->getLocation(), "function to override is here",
DiagnosticIDs::Note);
}
}
}