[ClangImporter] Compute initializer kinds up front (#27870)

Previously we only did this for factory methods, but there's no reason
why we can't do it for regular init methods too, and doing so
simplifies the signature of SwiftDeclConverter::importConstructor.

Also remove some indirection through helper functions in ClangAdapter.
These were more useful back when Swift looked directly at API notes
instead of relying on Clang turning them into attributes; now they're
just an extra hop for no reason.

lib/ClangImporter/ClangAdapter.cpp

@@ -601,29 +601,6 @@ OptionalTypeKind importer::translateNullability(clang::NullabilityKind kind) {
   llvm_unreachable("Invalid NullabilityKind.");
 }
 
-bool importer::hasDesignatedInitializers(
-    const clang::ObjCInterfaceDecl *classDecl) {
-  if (classDecl->hasDesignatedInitializers())
-    return true;
-
-  return false;
-}
-
-bool importer::isDesignatedInitializer(
-    const clang::ObjCInterfaceDecl *classDecl,
-    const clang::ObjCMethodDecl *method) {
-  // If the information is on the AST, use it.
-  if (classDecl->hasDesignatedInitializers()) {
-    auto *methodParent = method->getClassInterface();
-    if (!methodParent ||
-        methodParent->getCanonicalDecl() == classDecl->getCanonicalDecl()) {
-      return method->hasAttr<clang::ObjCDesignatedInitializerAttr>();
-    }
-  }
-
-  return false;
-}
-
 bool importer::isRequiredInitializer(const clang::ObjCMethodDecl *method) {
   // FIXME: No way to express this in Objective-C.
   return false;

lib/ClangImporter/ClangAdapter.h

@@ -111,15 +111,6 @@ bool hasNativeSwiftDecl(const clang::Decl *decl);
 /// Translation API nullability from an API note into an optional kind.
 OptionalTypeKind translateNullability(clang::NullabilityKind kind);
 
-/// Determine whether the given class has designated initializers,
-/// consulting
-bool hasDesignatedInitializers(const clang::ObjCInterfaceDecl *classDecl);
-
-/// Determine whether the given method is a designated initializer
-/// of the given class.
-bool isDesignatedInitializer(const clang::ObjCInterfaceDecl *classDecl,
-                             const clang::ObjCMethodDecl *method);
-
 /// Determine whether the given method is a required initializer
 /// of the given class.
 bool isRequiredInitializer(const clang::ObjCMethodDecl *method);

lib/ClangImporter/ImportDecl.cpp

@@ -4415,7 +4415,7 @@ namespace {
     ConstructorDecl *importConstructor(const clang::ObjCMethodDecl *objcMethod,
                                        DeclContext *dc,
                                        bool implicit,
-                                       Optional<CtorInitializerKind> kindIn,
+                                       CtorInitializerKind kind,
                                        bool required,
                                        ObjCSelector selector,
                                        ImportedName importedName,
@@ -6081,9 +6081,10 @@ ConstructorDecl *SwiftDeclConverter::importConstructor(
   }
 
   bool redundant;
-  auto result =
+  auto result = importConstructor(objcMethod, dc, implicit,
-      importConstructor(objcMethod, dc, implicit, kind, required, selector,
+                                  kind.getValueOr(importedName.getInitKind()),
-                        importedName, params, variadic, redundant);
+                                  required, selector, importedName, params,
+                                  variadic, redundant);
 
   // If this is a compatibility stub, mark it as such.
   if (result && correctSwiftName)
@@ -6193,7 +6194,7 @@ bool SwiftDeclConverter::existingConstructorIsWorse(
 /// constructor declaration appropriately.
 ConstructorDecl *SwiftDeclConverter::importConstructor(
     const clang::ObjCMethodDecl *objcMethod, DeclContext *dc, bool implicit,
-    Optional<CtorInitializerKind> kindIn, bool required, ObjCSelector selector,
+    CtorInitializerKind kind, bool required, ObjCSelector selector,
     ImportedName importedName, ArrayRef<const clang::ParmVarDecl *> args,
     bool variadic, bool &redundant) {
   redundant = false;
@@ -6202,35 +6203,6 @@ ConstructorDecl *SwiftDeclConverter::importConstructor(
   auto ownerNominal = dc->getSelfNominalTypeDecl();
   assert(ownerNominal && "Method in non-type context?");
 
-  // Find the interface, if we can.
-  const clang::ObjCInterfaceDecl *interface = nullptr;
-  if (auto classDecl = dyn_cast<ClassDecl>(ownerNominal)) {
-    interface =
-        dyn_cast_or_null<clang::ObjCInterfaceDecl>(classDecl->getClangDecl());
-  }
-
-  // If we weren't told what kind of initializer this should be,
-  // figure it out now.
-  CtorInitializerKind kind;
-
-  if (kindIn) {
-    kind = *kindIn;
-
-    // If we know this is a designated initializer, mark it as such.
-    if (interface && hasDesignatedInitializers(interface) &&
-        isDesignatedInitializer(interface, objcMethod))
-      kind = CtorInitializerKind::Designated;
-  } else {
-    // If the owning Objective-C class has designated initializers and this
-    // is not one of them, treat it as a convenience initializer.
-    if (interface && hasDesignatedInitializers(interface) &&
-        !isDesignatedInitializer(interface, objcMethod)) {
-      kind = CtorInitializerKind::Convenience;
-    } else {
-      kind = CtorInitializerKind::Designated;
-    }
-  }
-
   // Import the type that this method will have.
   Optional<ForeignErrorConvention> errorConvention;
   ParameterList *bodyParams;
@@ -7274,9 +7246,9 @@ void SwiftDeclConverter::importInheritedConstructors(
   };
 
   // The kind of initializer to import. If this class has designated
-  // initializers, everything it imports is a convenience initializer.
+  // initializers, everything it inherits is a convenience initializer.
   Optional<CtorInitializerKind> kind;
-  if (hasDesignatedInitializers(curObjCClass))
+  if (curObjCClass->hasDesignatedInitializers())
     kind = CtorInitializerKind::Convenience;
 
 

lib/ClangImporter/ImportName.cpp

@@ -740,9 +740,7 @@ getFactoryAsInit(const clang::ObjCInterfaceDecl *classDecl,
 /// should be stripped from the first selector piece, e.g., "init"
 /// or the restated name of the class in a factory method.
 ///
-///  \param kind Will be set to the kind of initializer being
+/// \param kind Will be set to the kind of initializer being imported.
-///  imported. Note that this does not distinguish designated
-///  vs. convenience; both will be classified as "designated".
 static bool shouldImportAsInitializer(const clang::ObjCMethodDecl *method,
                                       ImportNameVersion version,
                                       unsigned &prefixLength,
@@ -750,7 +748,17 @@ static bool shouldImportAsInitializer(const clang::ObjCMethodDecl *method,
   /// Is this an initializer?
   if (isInitMethod(method)) {
     prefixLength = 4;
+
+    // If the owning Objective-C class has designated initializers and this
+    // is not one of them, treat it as a convenience initializer.
+    const clang::ObjCInterfaceDecl *interface = method->getClassInterface();
+    if (interface && interface->hasDesignatedInitializers() &&
+        !method->hasAttr<clang::ObjCDesignatedInitializerAttr>()) {
+      kind = CtorInitializerKind::Convenience;
+    } else {
       kind = CtorInitializerKind::Designated;
+    }
+
     return true;
   }