================
@@ -347,6 +361,30 @@ static bool shouldTrackFirstArgument(const FunctionDecl
*FD) {
return false;
}
+// Returns true if we should perform the GSL analysis on the first argument for
+// the given constructor.
+static bool
+shouldTrackFirstArgumentForConstructor(const CXXConstructExpr *Ctor) {
+ const auto *ClassD = Ctor->getConstructor()->getParent();
+
+ auto FirstArgType = Ctor->getArg(0)->getType();
+ // Case 1, construct a GSL pointer, e.g. std::string_view
+ if (ClassD->hasAttr<PointerAttr>())
+ return true;
+
+ // case 2: construct a container of pointer (std::vector<std::string_view>)
+ // from an owner or a std::initilizer_list.
+ //
+ // std::initializer_list is a proxy object that provides access to the
backing
+ // array. We perform analysis on it to determine if there are any dangling
+ // temporaries in the backing array.
+ if (Ctor->getConstructor()->getNumParams() != 1 ||
+ !isContainerOfPointer(ClassD))
+ return false;
+ return isGSLOwner(FirstArgType) ||
+ isStdInitializerListOfPointer(FirstArgType->getAsRecordDecl());
----------------
hokein wrote:
> It looks like we mean to say that std::initialiser_list<Pointer> should be
> considered as GSL Owner.
I think what we actually intend is to continue tracking the argument of type
`std::initializer_list<Pointer>`. (while previously, we only tracked arguments
for GSL Owner types.) Conceptually, `std::initializer_list<Pointer>` is not an
owner, so moving this logic to `isGSLOwner` doesn't feel appropriate, even
though it works in practice.
Regarding the new false negative, it was introduced when we replaced instances
of isRecordWithAttr<OwnerAttr> in
[TemporaryVisitor](https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/CheckExprLifetime.cpp#L988)
with the new isGSLOwner function (which excludes `Owner<Pointer>` types). The
logic in `TemporaryVisitor` is a bit subtle, which is to skip reporting issues
if the local variable is not an owner type. Since `isGSLOwner` excludes
`vector<int*>`, it no longer triggers a report.
To fix this, I reverted the abstraction of isGSLOwner because the
`!isContainerOfPointer` logic only applies to determining whether to trace the
first argument of the `container<pointer>` constructor. I've added comments
there).
https://github.com/llvm/llvm-project/pull/108344
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