From 4bc57c0de7f5db34ea9279322e277e7a4da9b27b Mon Sep 17 00:00:00 2001
From: Steve Naroff <snaroff@apple.com>
Date: Wed, 8 Aug 2007 17:48:34 +0000
Subject: [PATCH] Add support for __builtin_classify_type(). This builtin
 function isn't "public", however it is used by "tgmath.h" (so we need to
 support it). It might also come in handy when developing the overloaded
 function macros for OpenCU.

Next check-in will make this an integer constant expression...

llvm-svn: 40930
---
 clang/AST/Builtins.cpp               | 16 +++++++++++++---
 clang/include/clang/AST/Builtins.def |  1 +
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/clang/AST/Builtins.cpp b/clang/AST/Builtins.cpp
index 454085bf2a52..099b1138d02d 100644
--- a/clang/AST/Builtins.cpp
+++ b/clang/AST/Builtins.cpp
@@ -88,7 +88,7 @@ static QualType DecodeTypeFromStr(const char *&Str, ASTContext &Context) {
   switch (*Str++) {
   default: assert(0 && "Unknown builtin type letter!");
   case 'v':
-    assert(!Long && !Signed && !Unsigned && "Bad modifiers used with 'f'!");
+    assert(!Long && !Signed && !Unsigned && "Bad modifiers used with 'v'!");
     return Context.VoidTy;
   case 'f':
     assert(!Long && !Signed && !Unsigned && "Bad modifiers used with 'f'!");
@@ -103,7 +103,14 @@ static QualType DecodeTypeFromStr(const char *&Str, ASTContext &Context) {
     if (Unsigned)
       return Context.UnsignedShortTy;
     return Context.ShortTy;
-  //case 'i':
+  case 'i':
+    if (Long)
+      return Unsigned ? Context.UnsignedLongTy : Context.LongTy;
+    if (LongLong)
+      return Unsigned ? Context.UnsignedLongLongTy : Context.LongLongTy;
+    if (Unsigned)
+      return Context.UnsignedIntTy;
+    return Context.IntTy; // default is signed.
   }
 }
 
@@ -119,7 +126,10 @@ QualType Builtin::Context::GetBuiltinType(unsigned id, ASTContext &Context)const
   
   assert((TypeStr[0] != '.' || TypeStr[1] == 0) &&
          "'.' should only occur at end of builtin type list!");
-  
+
+  // handle untyped/variadic arguments "T c99Style();" or "T cppStyle(...);".
+  if (ArgTypes.size() == 0 && TypeStr[0] == '.')
+    return Context.getFunctionTypeNoProto(ResType);
   return Context.getFunctionType(ResType, &ArgTypes[0], ArgTypes.size(),
                                  TypeStr[0] == '.');
 }
diff --git a/clang/include/clang/AST/Builtins.def b/clang/include/clang/AST/Builtins.def
index 97431da9512f..2a5a8c76a866 100644
--- a/clang/include/clang/AST/Builtins.def
+++ b/clang/include/clang/AST/Builtins.def
@@ -49,5 +49,6 @@ BUILTIN(__builtin_fabs , "dd"  , "nc")
 BUILTIN(__builtin_fabsf, "ff"  , "nc")
 BUILTIN(__builtin_fabsl, "LdLd", "nc")
 BUILTIN(__builtin_constant_p, "UsUs", "nc")
+BUILTIN(__builtin_classify_type, "i.", "nc")
 
 #undef BUILTIN