[clang] Reland: [clang] Diagnose dangling issues for the "Container<GSLPointer>" case. #107213 (PR #108344)

[Utkarsh Saxena via cfe-commits]

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@@ -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());
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usx95 wrote:

Thanks for the clarification.

https://github.com/llvm/llvm-project/pull/108344