[AST][SVE] Treat built-in SVE types as POD

[rsandifo-arm]

Summary

Built-in SVE types are POD in much the same that scalars and
fixed-length vectors are.

[efriedma]

clang/lib/AST/Type.cpp

2500

Can you rearrange this so isSizelessBuiltinType() is at the bottom? It should be rare. (Assuming it doesn't need to be before the isIncompleteType() check.)

[rsandifo-arm]

clang/lib/AST/Type.cpp

2500

I should have mentioned that, but yeah: the call is placed here so that it continues to work when/if IsCompleteType returns true for these types. (I have a patch for that, similar to D76221, but I don't know whether it will be acceptable.)

[efriedma]

Okay, then LGTM

clang/lib/AST/Type.cpp

if (hasNonTrivialObjCLifetime())
     return false;
 
   // C++11 [basic.types]p9:
   //   Scalar types, POD classes, arrays of such types, and cv-qualified
   //   versions of these types are collectively called trivial types.
   const Type *BaseTy = ty->getBaseElementTypeUnsafe();
   assert(BaseTy && "NULL element type");
 
+  if (BaseTy->isSizelessBuiltinType())
+    return true;
+
   // Return false for incomplete types after skipping any incomplete array
   // types which are expressly allowed by the standard and thus our API.
   if (BaseTy->isIncompleteType())
     return false;
 
   // As an extension, Clang treats vector types as Scalar types.
   if (BaseTy->isScalarType() || BaseTy->isVectorType()) return true;
   if (const auto *RT = BaseTy->getAs<RecordType>()) {

clang/test/SemaCXX/sizeless-1.cpp

#endif
   default:;
   }
 }
 
 int vararg_receiver(int count, svint8_t first, ...) {
   __builtin_va_list va;
 
   __builtin_va_start(va, first);
+  __builtin_va_arg(va, svint8_t);
   __builtin_va_end(va);
   return count;
 }
 
 struct sized_struct {
   int f1;
   svint8_t f2;     // expected-error {{field has sizeless type 'svint8_t'}}
   svint8_t f3 : 2; // expected-error {{field has sizeless type 'svint8_t'}}
#endif
   _Static_assert(!__is_constructible(svint8_t, svint8_t, svint8_t), "");
   _Static_assert(!__is_constructible(svint8_t, svint16_t), "");
   _Static_assert(__is_nothrow_constructible(svint8_t), "");
   _Static_assert(__is_nothrow_constructible(svint8_t, svint8_t), "");
   _Static_assert(!__is_nothrow_constructible(svint8_t, svint16_t), "");
   _Static_assert(!__is_assignable(svint8_t, svint8_t), "");
   _Static_assert(__is_assignable(svint8_t &, svint8_t), "");
   _Static_assert(!__is_assignable(svint8_t &, svint16_t), "");
+  _Static_assert(__has_nothrow_assign(svint8_t), "");
+  _Static_assert(__has_nothrow_move_assign(svint8_t), "");
+  _Static_assert(__has_nothrow_copy(svint8_t), "");
+  _Static_assert(__has_nothrow_constructor(svint8_t), "");
+  _Static_assert(__has_trivial_assign(svint8_t), "");
+  _Static_assert(__has_trivial_move_assign(svint8_t), "");
+  _Static_assert(__has_trivial_copy(svint8_t), "");
+  _Static_assert(__has_trivial_constructor(svint8_t), "");
+  _Static_assert(__has_trivial_move_constructor(svint8_t), "");
+  _Static_assert(__has_trivial_destructor(svint8_t), "");
   _Static_assert(!__has_virtual_destructor(svint8_t), "");
   _Static_assert(!__is_abstract(svint8_t), "");
   _Static_assert(!__is_aggregate(svint8_t), "");
   _Static_assert(!__is_base_of(svint8_t, svint8_t), "");
   _Static_assert(!__is_class(svint8_t), "");
   _Static_assert(__is_convertible_to(svint8_t, svint8_t), "");
   _Static_assert(!__is_convertible_to(svint8_t, svint16_t), "");
   _Static_assert(!__is_empty(svint8_t), "");
   _Static_assert(!__is_enum(svint8_t), "");
   _Static_assert(!__is_final(svint8_t), "");
   _Static_assert(!__is_literal(svint8_t), "");
+  _Static_assert(__is_pod(svint8_t), "");
   _Static_assert(!__is_polymorphic(svint8_t), "");
   _Static_assert(__is_object(svint8_t), "");
   _Static_assert(!__is_arithmetic(svint8_t), "");
   _Static_assert(!__is_floating_point(svint8_t), "");
   _Static_assert(!__is_integral(svint8_t), "");
   _Static_assert(!__is_void(svint8_t), "");
   _Static_assert(!__is_array(svint8_t), "");
   _Static_assert(!__is_function(svint8_t), "");