Delete CC_Default and use the target default CC everywhere

Summary:
Makes functions with implicit calling convention compatible with
function types with a matching explicit calling convention.  This fixes
things like calls to qsort(), which has an explicit __cdecl attribute on
the comparator in Windows headers.

Clang will now infer the calling convention from the declarator.  There
are two cases when the CC must be adjusted during redeclaration:
1. When defining a non-inline static method.
2. When redeclaring a function with an implicit or mismatched
convention.

Fixes PR13457, and allows clang to compile CommandLine.cpp for the
Microsoft C++ ABI.

Excellent test cases provided by Alexander Zinenko!

Reviewers: rsmith

Differential Revision: http://llvm-reviews.chandlerc.com/D1231

llvm-svn: 189412

1 files changed, 10 insertions, 1 deletions

diff --git a/clang/test/CodeGen/mrtd.c b/clang/test/CodeGen/mrtd.c
index a40a59ac0fc..8fa7cf02cea 100644
--- a/clang/test/CodeGen/mrtd.c
+++ b/clang/test/CodeGen/mrtd.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -mrtd -triple i386-unknown-freebsd9.0 -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -mrtd -triple i386-unknown-unknown -std=c89 -emit-llvm -o - %s | FileCheck %s
 
 void baz(int arg);
 
@@ -14,4 +14,13 @@ void foo(int arg) {
 
 // CHECK: declare x86_stdcallcc void @baz(i32)
 
+void qux(int arg, ...) { }
+// CHECK: define void @qux(i32 %arg, ...)
+
+void quux(int a1, int a2, int a3) {
+  qux(a1, a2, a3);
+}
+// CHECK-LABEL: define x86_stdcallcc void @quux
+// CHECK: call void (i32, ...)* @qux
+
 // CHECK: attributes [[NUW]] = { nounwind{{.*}} }