Give builtins and alloc/dealloc operators the default calling convention.

[erichkeane]

Summary

On SPIR targets, the default calling convention is SpirFunction.
However, operator new/delete and builtins were being created with CC_C.
The result is indirect references to new/delete (or builtins that are permitted
to be called indirectly have a mismatched type, as well as questionable codegen
in some cases.

This patch sets both to the default calling convention, so that it properly matches the calling convention of the target.

[rnk]

lgtm

cfe/trunk/lib/AST/ASTContext.cpp

QualType ASTContext::GetBuiltinType(unsigned Id,
   }
 
   if (Id == Builtin::BI__GetExceptionInfo)
     return {};
 
   assert((TypeStr[0] != '.' || TypeStr[1] == 0) &&
          "'.' should only occur at end of builtin type list!");
 
-  FunctionType::ExtInfo EI(CC_C);
+  bool Variadic = (TypeStr[0] == '.');
+
+  FunctionType::ExtInfo EI(
+      getDefaultCallingConvention(Variadic, /*IsCXXMethod=*/false));
   if (BuiltinInfo.isNoReturn(Id)) EI = EI.withNoReturn(true);
 
-  bool Variadic = (TypeStr[0] == '.');
 
   // We really shouldn't be making a no-proto type here.
   if (ArgTypes.empty() && Variadic && !getLangOpts().CPlusPlus)
     return getFunctionNoProtoType(ResType, EI);
 
   FunctionProtoType::ExtProtoInfo EPI;
   EPI.ExtInfo = EI;
   EPI.Variadic = Variadic;

cfe/trunk/lib/Sema/SemaExprCXX.cpp

if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
           // allocation function, or is suppressing that function.
           Func->setVisibleDespiteOwningModule();
           return;
         }
       }
     }
   }
 
-  FunctionProtoType::ExtProtoInfo EPI;
+  FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention(
+      /*IsVariadic=*/false, /*IsCXXMethod=*/false));
 
   QualType BadAllocType;
   bool HasBadAllocExceptionSpec
     = (Name.getCXXOverloadedOperator() == OO_New ||
        Name.getCXXOverloadedOperator() == OO_Array_New);
   if (HasBadAllocExceptionSpec) {
     if (!getLangOpts().CPlusPlus11) {
       BadAllocType = Context.getTypeDeclType(getStdBadAlloc());

cfe/trunk/test/CodeGenCXX/builtin-calling-conv.cpp

+// RUN: %clang_cc1 -triple x86_64-linux-pc -DREDECL -emit-llvm %s -o - | FileCheck %s -check-prefix LINUX
+// RUN: %clang_cc1 -triple spir-unknown-unknown -DREDECL -DSPIR -emit-llvm %s -o - | FileCheck %s -check-prefix SPIR
+// RUN: %clang_cc1 -triple x86_64-linux-pc -emit-llvm %s -o - | FileCheck %s -check-prefix LINUX
+// RUN: %clang_cc1 -triple spir-unknown-unknown -DSPIR -emit-llvm %s -o - | FileCheck %s -check-prefix SPIR
+
+#ifdef REDECL
+namespace std {
+#ifdef SPIR
+using size_t = unsigned int;
+#else
+using size_t = unsigned long;
+#endif // SPIR
+} // namespace std
+
+float __builtin_atan2f(float, float);
+void *operator new(std::size_t);
+#endif // REDECL
+
+void foo();
+
+void user() {
+  int i;
+  ::operator new(5);
+  (void)__builtin_atan2f(1.1, 2.2);
+  foo();
+}
+
+// LINUX: define void @_Z4userv()
+// LINUX: call i8* @_Znwm
+// LINUX: call float @atan2f
+// LINUX: call void @_Z3foov
+// LINUX: declare noalias i8* @_Znwm(i64)
+// LINUX: declare float @atan2f(float, float)
+// LINUX: declare void @_Z3foov()
+
+// SPIR: define spir_func void @_Z4userv()
+// SPIR: call spir_func i8* @_Znwj
+// SPIR: call spir_func float @atan2f
+// SPIR: call spir_func void @_Z3foov
+// SPIR: declare spir_func noalias i8* @_Znwj(i32)
+// SPIR: declare spir_func float @atan2f(float, float)
+// SPIR: declare spir_func void @_Z3foov()