[clang] fix -Wnullability-completeness false-positive in dependent code

[sam-mccall]

The intent was that smart-pointers do not participate in completeness
checks, but we failed to capture dependent unique_ptr<T>, which is not
a RecordType but a TemplateSpecializationType.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Sam McCall (sam-mccall)

Changes

The intent was that smart-pointers do not participate in completeness
checks, but we failed to capture dependent unique_ptr<T>, which is not
a RecordType but a TemplateSpecializationType.

---

Full diff: https://github.com/llvm/llvm-project/pull/88727.diff

2 Files Affected:

• (modified) clang/lib/Sema/SemaType.cpp (+2-1)
• (modified) clang/test/SemaObjCXX/Inputs/nullability-consistency-smart.h (+4)

diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 404c4e8e31b558..6ac8a9433c701b 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -4728,7 +4728,8 @@ static bool shouldHaveNullability(QualType T) {
          // It's unclear whether the pragma's behavior is useful for C++.
          // e.g. treating type-aliases and template-type-parameters differently
          // from types of declarations can be surprising.
-         !isa<RecordType>(T->getCanonicalTypeInternal());
+         !isa<RecordType, TemplateSpecializationType>(
+             T->getCanonicalTypeInternal());
 }
 
 static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
diff --git a/clang/test/SemaObjCXX/Inputs/nullability-consistency-smart.h b/clang/test/SemaObjCXX/Inputs/nullability-consistency-smart.h
index a28532e5d71668..5ff974af57f49b 100644
--- a/clang/test/SemaObjCXX/Inputs/nullability-consistency-smart.h
+++ b/clang/test/SemaObjCXX/Inputs/nullability-consistency-smart.h
@@ -5,3 +5,7 @@ void f1(int * _Nonnull);
 void f2(Smart); // OK, not required on smart-pointer types
 using Alias = Smart;
 void f3(Alias);
+
+template <class T> class _Nullable SmartTmpl;
+void f2(SmartTmpl<int>);
+template <class T> void f2(SmartTmpl<T>);