From 4c7b490d1921dd93685be9da9033101f99997025 Mon Sep 17 00:00:00 2001
From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Sat, 11 Feb 2012 18:03:45 +0000
Subject: [PATCH] Make sure to try instantiating a templated type which is used
 in an _Atomic before complaining that it's incomplete.

llvm-svn: 150308
---
 clang/lib/Sema/SemaType.cpp        | 12 +++++++-----
 clang/test/Sema/atomic-type.c      |  2 +-
 clang/test/SemaCXX/atomic-type.cxx | 12 ++++++++++++
 3 files changed, 20 insertions(+), 6 deletions(-)
 create mode 100644 clang/test/SemaCXX/atomic-type.cxx

diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index b402d3f2daaa..7d9a33af11f7 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -4402,12 +4402,14 @@ QualType Sema::BuildUnaryTransformType(QualType BaseType,
 
 QualType Sema::BuildAtomicType(QualType T, SourceLocation Loc) {
   if (!T->isDependentType()) {
+    // FIXME: It isn't entirely clear whether incomplete atomic types
+    // are allowed or not; for simplicity, ban them for the moment.
+    if (RequireCompleteType(Loc, T,
+                            PDiag(diag::err_atomic_specifier_bad_type) << 0))
+      return QualType();
+
     int DisallowedKind = -1;
-    if (T->isIncompleteType())
-      // FIXME: It isn't entirely clear whether incomplete atomic types
-      // are allowed or not; for simplicity, ban them for the moment.
-      DisallowedKind = 0;
-    else if (T->isArrayType())
+    if (T->isArrayType())
       DisallowedKind = 1;
     else if (T->isFunctionType())
       DisallowedKind = 2;
diff --git a/clang/test/Sema/atomic-type.c b/clang/test/Sema/atomic-type.c
index 8e725403ae90..a4ac5521091e 100644
--- a/clang/test/Sema/atomic-type.c
+++ b/clang/test/Sema/atomic-type.c
@@ -16,7 +16,7 @@ extern _Atomic(int (*)(int(*)[10], int(*)[])) mergetest;
 extern _Atomic(int (*)(int(*)[10], int(*)[10])) mergetest;
 
 _Atomic(int()) error1; // expected-error {{_Atomic cannot be applied to function type}}
-_Atomic(struct ErrorS) error2; // expected-error {{_Atomic cannot be applied to incomplete type}}
+_Atomic(struct ErrorS) error2; // expected-error {{_Atomic cannot be applied to incomplete type}} expected-note {{forward declaration}}
 _Atomic(int[10]) error3; // expected-error {{_Atomic cannot be applied to array type}}
 _Atomic(const int) error4; // expected-error {{_Atomic cannot be applied to qualified type}}
 _Atomic(_Atomic(int)) error5; // expected-error {{_Atomic cannot be applied to atomic type}}
diff --git a/clang/test/SemaCXX/atomic-type.cxx b/clang/test/SemaCXX/atomic-type.cxx
new file mode 100644
index 000000000000..adaff2a0a2f3
--- /dev/null
+++ b/clang/test/SemaCXX/atomic-type.cxx
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -verify %s
+
+template<typename T> struct atomic {
+  _Atomic(T) value;
+};
+
+template<typename T> struct user {
+  struct inner { char n[sizeof(T)]; };
+  atomic<inner> i;
+};
+
+user<int> u;