[BitwiseCopyable] Require Copyable, Escapable.

In order to conform to _BitwiseCopyable, require that a type not be
~Copyable or ~Escapable.  Once the stdlib is built with the relevant
feature flags, that checking will occur automatically.  Until then, have
these bespoke diagnostics.

Author: nate-chandler

include/swift/AST/DiagnosticsSema.def

@@ -7611,6 +7611,10 @@ ERROR(escapable_requires_feature_flag,none,
       ())
 ERROR(non_bitwise_copyable_type_class,none,
       "class cannot conform to 'BitwiseCopyable'", ())
+ERROR(non_bitwise_copyable_type_noncopyable,none,
+      "noncopyable type cannot conform to 'BitwiseCopyable'", ())
+ERROR(non_bitwise_copyable_type_nonescapable,none,
+      "nonescapable type cannot conform to 'BitwiseCopyable'", ())
 ERROR(non_bitwise_copyable_type_member,none,
       "%select{stored property %2|associated value %2}1 of "
       "'BitwiseCopyable'-conforming %kind3 has non-bitwise-copyable type %0",

lib/Sema/TypeCheckBitwise.cpp

@@ -222,6 +222,16 @@ static bool checkBitwiseCopyableInstanceStorage(NominalTypeDecl *nominal,
   assert(dc->getParentModule()->getASTContext().getProtocol(
       KnownProtocolKind::BitwiseCopyable));
 
+  if (dc->mapTypeIntoContext(nominal->getDeclaredInterfaceType())->isNoncopyable()) {
+    nominal->diagnose(diag::non_bitwise_copyable_type_noncopyable);
+    return true;
+  }
+
+  if (!dc->mapTypeIntoContext(nominal->getDeclaredInterfaceType())->isEscapable()) {
+    nominal->diagnose(diag::non_bitwise_copyable_type_nonescapable);
+    return true;
+  }
+
   if (isa<ClassDecl>(nominal)) {
     if (!isImplicit(check)) {
       nominal->diagnose(diag::non_bitwise_copyable_type_class);

test/Sema/bitwise_copyable.swift

@@ -1,7 +1,9 @@
-// RUN: %target-typecheck-verify-swift                   \
-// RUN:     -disable-availability-checking               \
-// RUN:     -enable-experimental-feature BitwiseCopyable \
-// RUN:     -enable-builtin-module                       \
+// RUN: %target-typecheck-verify-swift                       \
+// RUN:     -disable-availability-checking                   \
+// RUN:     -enable-experimental-feature NonescapableTypes   \
+// RUN:     -enable-experimental-feature NoncopyableGenerics \
+// RUN:     -enable-experimental-feature BitwiseCopyable     \
+// RUN:     -enable-builtin-module                           \
 // RUN:     -debug-diagnostic-names
 
 //==============================================================================
@@ -154,8 +156,8 @@ func passAnyAny(_ a: any Any) { take3(a) } // expected-error {{type_does_not_con
 func passString(_ s: String) { take3(s) } // expected-error    {{type_does_not_conform_decl_owner}}
                                           // expected-note@-17 {{where_requirement_failure_one_subst}}
 
-extension Optional {
-  struct Some : _BitwiseCopyable {
+extension Optional where Wrapped : Copyable & Escapable {
+  struct Some : _BitwiseCopyable & Copyable & Escapable {
     var wrapped: Wrapped // expected-error {{non_bitwise_copyable_type_member}}
   }
 }
@@ -184,6 +186,10 @@ struct S_Explicit_With_2_BitwiseCopyable_Generic_Optional<T : _BitwiseCopyable>
   var o2: T?
 }
 
+struct S_Explicit_Nonescapable : ~Escapable, _BitwiseCopyable {} // expected-error{{non_bitwise_copyable_type_nonescapable}}
+
+struct S_Explicit_Noncopyable : ~Copyable, _BitwiseCopyable {} // expected-error{{non_bitwise_copyable_type_noncopyable}}
+
 //==============================================================================
 //==========================STDLIB-DEPENDENCY TESTS=(BEGIN)==================={{
 //==============================================================================