From ceb66521ba155ad250e54f8142a2034af7ab3210 Mon Sep 17 00:00:00 2001
From: Akira Hatanaka <ahatanaka@apple.com>
Date: Tue, 13 Mar 2018 23:37:51 +0000
Subject: [PATCH] Check that a field is not annotated with attribute
 "unavailable" before setting the NonTrivialToPrimitive* flags of a record.

Union fields that have non-trivial Objective-C ownership qualifications
are normally not legal, but if the union is declared in a system header,
the fields are annotated with attribute "unavailable".

rdar://problem/38431072

llvm-svn: 327464
---
 clang/lib/Sema/SemaDecl.cpp                     |  2 +-
 clang/test/CodeGenObjC/Inputs/strong_in_union.h | 10 ++++++++++
 clang/test/CodeGenObjC/strong-in-c-struct.m     | 15 ++++++++++++---
 3 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 clang/test/CodeGenObjC/Inputs/strong_in_union.h

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 577724b..db598b0 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -15442,7 +15442,7 @@ void Sema::ActOnFields(Scope *S, SourceLocation RecLoc, Decl *EnclosingDecl,
       }
     }
 
-    if (Record && !getLangOpts().CPlusPlus) {
+    if (Record && !getLangOpts().CPlusPlus && !FD->hasAttr<UnavailableAttr>()) {
       QualType FT = FD->getType();
       if (FT.isNonTrivialToPrimitiveDefaultInitialize())
         Record->setNonTrivialToPrimitiveDefaultInitialize(true);
diff --git a/clang/test/CodeGenObjC/Inputs/strong_in_union.h b/clang/test/CodeGenObjC/Inputs/strong_in_union.h
new file mode 100644
index 0000000..abe4549
--- /dev/null
+++ b/clang/test/CodeGenObjC/Inputs/strong_in_union.h
@@ -0,0 +1,10 @@
+#ifndef STRONG_IN_UNION_H
+#define STRONG_IN_UNION_H
+#pragma clang system_header
+
+typedef union {
+  id f0;
+  int *f1;
+} U;
+
+#endif // STRONG_IN_UNION_H
diff --git a/clang/test/CodeGenObjC/strong-in-c-struct.m b/clang/test/CodeGenObjC/strong-in-c-struct.m
index 11291f7..6310943 100644
--- a/clang/test/CodeGenObjC/strong-in-c-struct.m
+++ b/clang/test/CodeGenObjC/strong-in-c-struct.m
@@ -1,10 +1,11 @@
-// RUN: %clang_cc1 -triple arm64-apple-ios11 -fobjc-arc -fblocks  -fobjc-runtime=ios-11.0 -emit-llvm -o - -DUSESTRUCT %s | FileCheck %s
+// RUN: %clang_cc1 -triple arm64-apple-ios11 -fobjc-arc -fblocks  -fobjc-runtime=ios-11.0 -emit-llvm -o - -DUSESTRUCT -I %S/Inputs %s | FileCheck %s
 
-// RUN: %clang_cc1 -triple arm64-apple-ios11 -fobjc-arc -fblocks  -fobjc-runtime=ios-11.0 -emit-pch -o %t %s
-// RUN: %clang_cc1 -triple arm64-apple-ios11 -fobjc-arc -fblocks  -fobjc-runtime=ios-11.0 -include-pch %t -emit-llvm -o - -DUSESTRUCT %s | FileCheck %s
+// RUN: %clang_cc1 -triple arm64-apple-ios11 -fobjc-arc -fblocks  -fobjc-runtime=ios-11.0 -emit-pch -I %S/Inputs -o %t %s
+// RUN: %clang_cc1 -triple arm64-apple-ios11 -fobjc-arc -fblocks  -fobjc-runtime=ios-11.0 -include-pch %t -emit-llvm -o - -DUSESTRUCT -I %S/Inputs %s | FileCheck %s
 
 #ifndef HEADER
 #define HEADER
+#include "strong_in_union.h"
 
 typedef void (^BlockTy)(void);
 
@@ -531,4 +532,12 @@ void test_copy_constructor_Bitfield1(Bitfield1 *a) {
   Bitfield1 t = *a;
 }
 
+// CHECK: define void @test_strong_in_union()
+// CHECK: alloca %{{.*}}
+// CHECK-NEXT: ret void
+
+void test_strong_in_union() {
+  U t;
+}
+
 #endif /* USESTRUCT */
-- 
2.7.4