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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150241 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/test/SemaCXX/trailing-return-0x.cpp b/test/SemaCXX/trailing-return-0x.cpp
index e25939fa3e..c219b77d9e 100644
--- a/test/SemaCXX/trailing-return-0x.cpp
+++ b/test/SemaCXX/trailing-return-0x.cpp
@@ -21,6 +21,16 @@ auto g(); // expected-error{{return without trailing return type}}
 
 int h() -> int; // expected-error{{trailing return type must specify return type 'auto', not 'int'}}
 
+int i();
+auto i() -> int;
+int i() {}
+
+using T = auto (int) -> auto (*)(char) -> void; // expected-note {{previous}}
+using T = void; // expected-error {{type alias redefinition with different types ('void' vs 'auto (int) -> auto (*)(char) -> void')}}
+
+using U = auto (int) -> auto (*)(char) -> void;
+using U = void (*(int))(char); // ok
+
 int x;
 
 template <class T>