From 812bdb3c13210759341e8a1b08b864a539ce9dc7 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Wed, 30 Oct 2019 14:38:11 -0700
Subject: [PATCH] [MS] Don't reference deleted copy ctors from catchable types

When throwing objects with deleted copy constructors, the copy ctor
field of the catchable type should remain null and the mangle name
changes. This already worked in simple cases, but in cases involving
non-trivial subobjects, sometimes LookupCopyingConstructor could return
a non-null but deleted constructor decl. Skip those and don't reference
them.

Fixes PR43680
---
 clang/lib/Sema/SemaExprCXX.cpp                |  2 +-
 clang/test/CodeGenCXX/microsoft-abi-throw.cpp | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 4fdd15b..67492a2 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -921,7 +921,7 @@ bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc,
       // cannot be a simple walk of the class's decls.  Instead, we must perform
       // lookup and overload resolution.
       CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0);
-      if (!CD)
+      if (!CD || CD->isDeleted())
         continue;
 
       // Mark the constructor referenced as it is used by this throw expression.
diff --git a/clang/test/CodeGenCXX/microsoft-abi-throw.cpp b/clang/test/CodeGenCXX/microsoft-abi-throw.cpp
index f55b94a..937f2da 100644
--- a/clang/test/CodeGenCXX/microsoft-abi-throw.cpp
+++ b/clang/test/CodeGenCXX/microsoft-abi-throw.cpp
@@ -14,6 +14,8 @@
 // CHECK-DAG: @"_CTA5?AUY@@" = linkonce_odr unnamed_addr constant %eh.CatchableTypeArray.5 { i32 5, [5 x %eh.CatchableType*] [%eh.CatchableType* @"_CT??_R0?AUY@@@8??0Y@@QAE@ABU0@@Z8", %eh.CatchableType* @"_CT??_R0?AUZ@@@81", %eh.CatchableType* @"_CT??_R0?AUW@@@8??0W@@QAE@ABU0@@Z44", %eh.CatchableType* @"_CT??_R0?AUM@@@818", %eh.CatchableType* @"_CT??_R0?AUV@@@81044"] }, section ".xdata", comdat
 // CHECK-DAG: @"_TI5?AUY@@" = linkonce_odr unnamed_addr constant %eh.ThrowInfo { i32 0, i8* bitcast (void (%struct.Y*)* @"??_DY@@QAEXXZ" to i8*), i8* null, i8* bitcast (%eh.CatchableTypeArray.5* @"_CTA5?AUY@@" to i8*) }, section ".xdata", comdat
 // CHECK-DAG: @"_CT??_R0?AUDefault@@@8??_ODefault@@QAEXAAU0@@Z1" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 0, i8* bitcast (%rtti.TypeDescriptor13* @"??_R0?AUDefault@@@8" to i8*), i32 0, i32 -1, i32 0, i32 1, i8* bitcast (void (%struct.Default*, %struct.Default*)* @"??_ODefault@@QAEXAAU0@@Z" to i8*) }, section ".xdata", comdat
+// CHECK-DAG: @"_CT??_R0?AUDeletedCopy@@@81" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 0, i8* bitcast (%rtti.TypeDescriptor17* @"??_R0?AUDeletedCopy@@@8" to i8*), i32 0, i32 -1, i32 0, i32 1, i8* null }, section ".xdata", comdat
+// CHECk-DAG: @"_CT??_R0?AUMoveOnly@@@84" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 0, i8* bitcast (%rtti.TypeDescriptor14* @"??_R0?AUMoveOnly@@@8" to i8*), i32 0, i321-1, i32 0, i32 4, i8* null }, section ".xdata", comda
 // CHECK-DAG: @"_CT??_R0?AUVariadic@@@8??_OVariadic@@QAEXAAU0@@Z1" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 0, i8* bitcast (%rtti.TypeDescriptor14* @"??_R0?AUVariadic@@@8" to i8*), i32 0, i32 -1, i32 0, i32 1, i8* bitcast (void (%struct.Variadic*, %struct.Variadic*)* @"??_OVariadic@@QAEXAAU0@@Z" to i8*) }, section ".xdata", comdat
 // CHECK-DAG: @"_CT??_R0?AUTemplateWithDefault@@@8??$?_OH@TemplateWithDefault@@QAEXAAU0@@Z1" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 0, i8* bitcast (%rtti.TypeDescriptor25* @"??_R0?AUTemplateWithDefault@@@8" to i8*), i32 0, i32 -1, i32 0, i32 1, i8* bitcast (void (%struct.TemplateWithDefault*, %struct.TemplateWithDefault*)* @"??$?_OH@TemplateWithDefault@@QAEXAAU0@@Z" to i8*) }, section ".xdata", comdat
 // CHECK-DAG: @"_CTA2$$T" = linkonce_odr unnamed_addr constant %eh.CatchableTypeArray.2 { i32 2, [2 x %eh.CatchableType*] [%eh.CatchableType* @"_CT??_R0$$T@84", %eh.CatchableType* @"_CT??_R0PAX@84"] }, section ".xdata", comdat
@@ -71,6 +73,31 @@ void h(Default &d) {
   throw d;
 }
 
+struct DeletedCopy {
+  DeletedCopy();
+  DeletedCopy(DeletedCopy &&);
+  DeletedCopy(const DeletedCopy &) = delete;
+};
+void throwDeletedCopy() { throw DeletedCopy(); }
+
+
+struct MoveOnly {
+  MoveOnly();
+  MoveOnly(MoveOnly &&);
+  ~MoveOnly();
+  MoveOnly(const MoveOnly &) = delete;
+
+  // For some reason this subobject was important for reproducing PR43680
+  struct HasCopy {
+    HasCopy();
+    HasCopy(const HasCopy &o);
+    ~HasCopy();
+    int x;
+  } sub;
+};
+
+void throwMoveOnly() { throw MoveOnly(); }
+
 struct Variadic {
   Variadic(Variadic &, ...);
 };
-- 
2.7.4