Track whether a function type has a trailing return type as type sugar. Use this

to pretty-print such function types better, and to fix a case where we were not
instantiating templates in lexical order. In passing, move the Variadic bit from
Type's bitfields to FunctionProtoType to get the Type bitfields down to 32 bits.
Also ensure that we always substitute the return type of a function when
substituting explicitly-specified arguments, since that can cause us to bail
out with a SFINAE error before we hit a hard error in parameter substitution.

llvm-svn: 150241

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/test/PCH/cxx-trailing-return.cpp b/clang/test/PCH/cxx-trailing-return.cpp
new file mode 100644
index 00000000000..ff85f6d1c5f
--- /dev/null
+++ b/clang/test/PCH/cxx-trailing-return.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -pedantic-errors -std=c++11 -emit-pch %s -o %t-cxx11
+// RUN: %clang_cc1 -pedantic-errors -std=c++11 -include-pch %t-cxx11 -verify %s
+
+#ifndef HEADER_INCLUDED
+
+#define HEADER_INCLUDED
+typedef auto f() -> int; // expected-note {{here}}
+typedef int g(); // expected-note {{here}}
+
+#else
+
+typedef void f; // expected-error {{typedef redefinition with different types ('void' vs 'auto () -> int')}}
+typedef void g; // expected-error {{typedef redefinition with different types ('void' vs 'int ()')}}
+
+#endif