From 2271162571bf966110924679d099aabe7b3c12c4 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <reid@kleckner.net>
Date: Thu, 1 May 2014 16:50:23 +0000
Subject: [PATCH] MSVCCompat: Don't produce an invalid AST when accepting void
 pseudo-dtors

We accept 'void *p; p->~void();' for MSVC compatibility since r148682.
However, we were returning ExprError, rather than producing an AST,
despite only diagnosing it with a warning.  CodeGen noticed that the
template function specialization had an invalid AST, and therefore
didn't generate code for it.  This change makes us produce an AST with a
void pseudo-dtor call.

Part of PR18256.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207771 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaExprCXX.cpp                    |  5 +++--
 test/CodeGenCXX/microsoft-compatibility.cpp | 21 +++++++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 test/CodeGenCXX/microsoft-compatibility.cpp

diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 81fabd4b20..6f60406a4e 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -5378,10 +5378,11 @@ ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base,
       !ObjectType->isVectorType()) {
     if (getLangOpts().MSVCCompat && ObjectType->isVoidType())
       Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange();
-    else
+    else {
       Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar)
         << ObjectType << Base->getSourceRange();
-    return ExprError();
+      return ExprError();
+    }
   }
 
   // C++ [expr.pseudo]p2:
diff --git a/test/CodeGenCXX/microsoft-compatibility.cpp b/test/CodeGenCXX/microsoft-compatibility.cpp
new file mode 100644
index 0000000000..297184a1df
--- /dev/null
+++ b/test/CodeGenCXX/microsoft-compatibility.cpp
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 %s -triple i686-pc-win32 -std=c++11 -fms-compatibility -emit-llvm -o - | FileCheck %s
+
+template<class T>
+void destroy(T *p) {
+  p->~T();
+}
+
+extern "C" void f() {
+  int a;
+  destroy((void*)&a);
+}
+
+// CHECK-LABEL: define void @f()
+// CHECK: call void @"\01??$destroy@X@@YAXPAX@Z"
+// CHECK: ret void
+
+// CHECK-LABEL: define linkonce_odr void @"\01??$destroy@X@@YAXPAX@Z"(i8* %p)
+//    The pseudo-dtor expr should not generate calls to anything.
+// CHECK-NOT: call
+// CHECK-NOT: invoke
+// CHECK: ret void
-- 
2.40.0