Give builtins and alloc/dealloc operators the default calling convent…

…ion.

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.

Differential Revision: https://reviews.llvm.org/D58844

Change-Id: I52065bb00bc2655945caea8f29c409ba1e0ac24a
llvm-svn: 355317

clang/lib/AST/ASTContext.cpp

@@ -9565,10 +9565,12 @@ QualType ASTContext::GetBuiltinType(unsigned Id,
   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)

clang/lib/Sema/SemaExprCXX.cpp

@@ -2795,7 +2795,8 @@ void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
     }
   }
 
-  FunctionProtoType::ExtProtoInfo EPI;
+  FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention(
+      /*IsVariadic=*/false, /*IsCXXMethod=*/false));
 
   QualType BadAllocType;
   bool HasBadAllocExceptionSpec

clang/test/CodeGenCXX/builtin-calling-conv.cpp

@@ -0,0 +1,42 @@
+// 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()