[llvm-branch-commits] [clang] release/21.x: [Clang] Fix an error-recovery crash after d1a80dea (#159976) (PR #159980)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/159980

Backport 90a6b000

Requested by: @zyn0217

>From 506376895a557d7edcdd9c5c85ae8c2e2c193b25 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Sun, 21 Sep 2025 21:55:59 +0800
Subject: [PATCH] [Clang] Fix an error-recovery crash after d1a80dea (#159976)

d1a80dea tried to ensure a TypeSourceInfo for a destructor name.
However, we don't actually have one during error recovery, so we should
bail in that case.

No release note, since it's a regression and a backport could improve
the stability of clangd.

Fixes https://github.com/llvm/llvm-project/issues/159630

(cherry picked from commit 90a6b0002d1ba7d6cbfe67942bf7499f1f011d65)
---
 clang/lib/Sema/SemaExprCXX.cpp                  |  2 ++
 clang/test/SemaTemplate/destructor-template.cpp | 15 +++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 25afa2f4dfe7a..a08971c6526fe 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -347,6 +347,8 @@ ParsedType Sema::getDestructorName(const IdentifierInfo &II,
         CheckTypenameType(ElaboratedTypeKeyword::None, SourceLocation(),
                           SS.getWithLocInContext(Context), II, NameLoc, &TSI,
                           /*DeducedTSTContext=*/true);
+    if (T.isNull())
+      return ParsedType();
     return CreateParsedType(T, TSI);
   }
 
diff --git a/clang/test/SemaTemplate/destructor-template.cpp b/clang/test/SemaTemplate/destructor-template.cpp
index 7a3398308bbee..734269e854e5d 100644
--- a/clang/test/SemaTemplate/destructor-template.cpp
+++ b/clang/test/SemaTemplate/destructor-template.cpp
@@ -104,3 +104,18 @@ struct T : S {
   ~T() = default;
 };
 } // namespace PR38671
+
+namespace GH159630 {
+
+struct X {
+  template<typename T>
+  struct typo { // expected-note {{'typo' declared here}}
+    ~typo();
+  };
+};
+
+template<typename T>
+X::typo<T>::typ0::~typ0() {} // expected-error {{no member named 'typ0'}} \
+                             // expected-error {{no type named 'typ0'}}
+
+}