From 94e164144c64ea7596221cb98dfa6f06c123e14f Mon Sep 17 00:00:00 2001
From: Telgome <2657726985@qq.com>
Date: Thu, 18 Sep 2025 21:44:18 +0800
Subject: [PATCH] Add support for '~auto' pseudo-destructor

---
 .../clang/Basic/DiagnosticParseKinds.td       |  5 +++++
 clang/lib/Parse/ParseExprCXX.cpp              | 18 +++++++++++++++
 clang/lib/Sema/SemaExprCXX.cpp                |  4 +++-
 clang/test/SemaCXX/auto-dtor.cpp              | 22 +++++++++++++++++++
 4 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/SemaCXX/auto-dtor.cpp

diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
index 12aab09f2855..e22712871465 100644
--- a/clang/include/clang/Basic/DiagnosticParseKinds.td
+++ b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -389,6 +389,11 @@ def warn_cxx11_compat_decltype_auto_type_specifier : Warning<
 def ext_auto_type : Extension<
   "'__auto_type' is a GNU extension">,
   InGroup<GNUAutoType>;
+def warn_cxx11_compat_pseudo_destructor_auto : Warning<
+  "'~auto' only available with '-std=c++14 or -std=gnu++14'">,
+  InGroup<CXX11Compat>, DefaultIgnore;
+def err_requires_gnu_compatibility_for_auto_dtor : Error<
+  "'~auto' pseudo-destructor requires -fGNU-compatibility flag">;
 def ext_for_range : ExtWarn<
   "range-based for loop is a C++11 extension">, InGroup<CXX11>;
 def warn_cxx98_compat_for_range : Warning<
diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index 1d364f77a814..01e1190c7ebd 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -1884,6 +1884,24 @@ Parser::ParseCXXPseudoDestructor(Expr *Base, SourceLocation OpLoc,
   assert(Tok.is(tok::tilde) && "ParseOptionalCXXScopeSpecifier fail");
   SourceLocation TildeLoc = ConsumeToken();
 
+  if (Tok.is(tok::kw_auto) && !FirstTypeName.isValid()) {
+    if (!getLangOpts().GccCompatible) {
+      Diag(Tok, diag::err_requires_gnu_compatibility_for_auto_dtor);
+      return ExprError();
+    } else {
+      if (!getLangOpts().CPlusPlus14)
+        Diag(Tok, diag::warn_cxx11_compat_pseudo_destructor_auto);
+    }
+
+    ConsumeToken();
+    UnqualifiedId SecondTypeName;
+    SecondTypeName.setIdentifier(nullptr, SourceLocation());
+
+   return Actions.ActOnPseudoDestructorExpr(getCurScope(), Base, OpLoc, OpKind,
+                                            SS, FirstTypeName, CCLoc, TildeLoc,
+                                            SecondTypeName);
+  }
+
   if (Tok.is(tok::kw_decltype) && !FirstTypeName.isValid()) {
     DeclSpec DS(AttrFactory);
     ParseDecltypeSpecifier(DS);
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index de50786f4d6c..3348abea6950 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -8195,7 +8195,9 @@ ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
   QualType DestructedType;
   TypeSourceInfo *DestructedTypeInfo = nullptr;
   PseudoDestructorTypeStorage Destructed;
-  if (SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) {
+  if (!SecondTypeName.Identifier) {
+    DestructedType = ObjectType;
+  } else if (SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) {
     ParsedType T = getTypeName(*SecondTypeName.Identifier,
                                SecondTypeName.StartLocation,
                                S, &SS, true, false, ObjectTypePtrForLookup,
diff --git a/clang/test/SemaCXX/auto-dtor.cpp b/clang/test/SemaCXX/auto-dtor.cpp
new file mode 100644
index 000000000000..3375208b0cb1
--- /dev/null
+++ b/clang/test/SemaCXX/auto-dtor.cpp
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -std=c++14 -Werror -Wno-error=c++14-extensions -fsyntax-only %s -fGNU-compatibility
+// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11 -Wc++11-compat -fGNU-compatibility
+
+template <class T>
+void f (T* p)
+{
+  p->~auto(); // expected-warning {{'~auto' only available with '-std=c++14 or -std=gnu++14'}}
+}
+
+int d;
+struct A { ~A() { ++d; } };
+
+int g (int x)
+{
+  f(new int(x));
+  f(new A);
+  if (d != 1) {
+    return 1;
+  }
+  (new int)->~auto(); // expected-warning {{'~auto' only available with '-std=c++14 or -std=gnu++14'}}
+  return 0;
+}
-- 
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