[PrintAsObjC] Only include internal decls if we have a bridging header.

The upshot of this is that internal decls in an app target will be in the
generated header but internal decls in a framework target will not. This
is important since the generated header is part of a framework's public
interface. Users always have the option to add members via category to an
internal framework type they need to use from Objective-C, or to write the
@interface themselves if the entire type is missing. Only internal protocols
are left out by this.

The presence of the bridging header isn't a /perfect/ way to decide this,
but it's close enough. In an app target without a bridging header, it's
unlikely that there will be ObjC sources depending on the generated header.

Swift SVN r19763

include/swift/PrintAsObjC/PrintAsObjC.h

@@ -14,6 +14,7 @@
 #define SWIFT_PRINTASOBJC_H
 
 #include "swift/Basic/LLVM.h"
+#include "swift/AST/Attr.h"
 
 namespace swift {
   class Module;
@@ -22,7 +23,8 @@ namespace swift {
   /// header.
   ///
   /// Returns true on error.
-  bool printAsObjC(raw_ostream &out, Module *M, StringRef bridgingHeader);
+  bool printAsObjC(raw_ostream &out, Module *M, StringRef bridgingHeader,
+                   Accessibility minRequiredAccess);
 }
 
 #endif

lib/PrintAsObjC/PrintAsObjC.cpp

@@ -30,10 +30,6 @@
 
 using namespace swift;
 
-static bool isNonPrivateObjC(const ValueDecl *VD) {
-  return VD->isObjC() && VD->getAccessibility() != Accessibility::Private;
-}
-
 namespace {
 class ObjCPrinter : private DeclVisitor<ObjCPrinter>,
                     private TypeVisitor<ObjCPrinter> {
@@ -51,19 +47,25 @@ class ObjCPrinter : private DeclVisitor<ObjCPrinter>,
 
   SmallVector<const FunctionType *, 4> openFunctionTypes;
 
+  Accessibility minRequiredAccess;
   bool protocolMembersOptional = false;
 
   friend ASTVisitor<ObjCPrinter>;
   friend TypeVisitor<ObjCPrinter>;
 
 public:
-  explicit ObjCPrinter(ASTContext &context, raw_ostream &out)
+  explicit ObjCPrinter(ASTContext &context, raw_ostream &out,
-    : ctx(context), os(out) {}
+                       Accessibility access)
+    : ctx(context), os(out), minRequiredAccess(access) {}
 
   void print(const Decl *D) {
     visit(const_cast<Decl *>(D));
   }
 
+  bool shouldInclude(const ValueDecl *VD) {
+    return VD->isObjC() && VD->getAccessibility() >= minRequiredAccess;
+  }
+
 private:
   using ASTVisitor::visit;
 
@@ -75,8 +77,8 @@ private:
     SmallVector<ProtocolDecl *, 4> protosToPrint;
     std::copy_if(protos.begin(), protos.end(),
                  std::back_inserter(protosToPrint),
-                 [](const ProtocolDecl *PD) -> bool {
+                 [this](const ProtocolDecl *PD) -> bool {
-      if (!isNonPrivateObjC(PD))
+      if (!shouldInclude(PD))
         return false;
       auto knownProtocol = PD->getKnownProtocolKind();
       if (!knownProtocol)
@@ -105,7 +107,7 @@ private:
   void printMembers(DeclRange members) {
     for (auto member : members) {
       auto VD = dyn_cast<ValueDecl>(member);
-      if (!VD || !isNonPrivateObjC(VD))
+      if (!VD || !shouldInclude(VD))
         continue;
       if (auto FD = dyn_cast<FuncDecl>(VD))
         if (FD->isAccessor())
@@ -751,8 +753,8 @@ class ModuleWriter {
   StringRef bridgingHeader;
   ObjCPrinter printer;
 public:
-  ModuleWriter(Module &mod, StringRef header)
+  ModuleWriter(Module &mod, StringRef header, Accessibility access)
-    : M(mod), bridgingHeader(header), printer(M.Ctx, os) {}
+    : M(mod), bridgingHeader(header), printer(M.Ctx, os, access) {}
 
   /// Returns true if we added the decl's module to the import set, false if
   /// the decl is a local decl.
@@ -812,7 +814,7 @@ public:
   void forwardDeclareMemberTypes(DeclRange members) {
     for (auto member : members) {
       auto VD = dyn_cast<ValueDecl>(member);
-      if (!VD || !isNonPrivateObjC(VD))
+      if (!VD || !printer.shouldInclude(VD))
         continue;
       ReferencedTypeFinder::walk(VD->getType(),
                                  [this](ReferencedTypeFinder &finder,
@@ -849,7 +851,7 @@ public:
       allRequirementsSatisfied &= require(superclass);
     }
     for (auto proto : CD->getProtocols())
-      if (isNonPrivateObjC(proto))
+      if (printer.shouldInclude(proto))
         allRequirementsSatisfied &= require(proto);
 
     if (!allRequirementsSatisfied)
@@ -894,7 +896,7 @@ public:
     const ClassDecl *CD = ED->getExtendedType()->getClassOrBoundGenericClass();
     allRequirementsSatisfied &= require(CD);
     for (auto proto : ED->getProtocols())
-      if (isNonPrivateObjC(proto))
+      if (printer.shouldInclude(proto))
         allRequirementsSatisfied &= require(proto);
 
     if (!allRequirementsSatisfied)
@@ -1018,13 +1020,13 @@ public:
     M.getTopLevelDecls(decls);
 
     auto newEnd = std::remove_if(decls.begin(), decls.end(),
-                                 [] (const Decl *D) -> bool {
+                                 [this](const Decl *D) -> bool {
       if (auto VD = dyn_cast<ValueDecl>(D))
-        return !isNonPrivateObjC(VD);
+        return !printer.shouldInclude(VD);
 
       if (auto ED = dyn_cast<ExtensionDecl>(D)) {
         auto baseClass = ED->getExtendedType()->getClassOrBoundGenericClass();
-        return !baseClass || !isNonPrivateObjC(baseClass);
+        return !baseClass || !printer.shouldInclude(baseClass);
       }
       return true;
     });
@@ -1135,6 +1137,7 @@ public:
 }
 
 bool swift::printAsObjC(llvm::raw_ostream &os, Module *M,
-                        StringRef bridgingHeader) {
+                        StringRef bridgingHeader,
-  return ModuleWriter(*M, bridgingHeader).writeToStream(os);
+                        Accessibility minRequiredAccess) {
+  return ModuleWriter(*M, bridgingHeader, minRequiredAccess).writeToStream(os);
 }

test/PrintAsObjC/accessibility.swift

@@ -0,0 +1,22 @@
+// RUN: rm -rf %t && mkdir %t
+// RUN: %swift %s -parse -emit-objc-header-path %t/accessibility.h
+// RUN: FileCheck -check-prefix=CHECK -check-prefix=CHECK-PUBLIC %s < %t/accessibility.h
+// RUN: %check-in-clang %t/accessibility.h
+
+// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache %s -parse -import-objc-header %S/../Inputs/empty.h -emit-objc-header-path %t/accessibility-internal.h
+// RUN: FileCheck -check-prefix=CHECK -check-prefix=CHECK-INTERNAL %s < %t/accessibility-internal.h
+// RUN: %check-in-clang %t/accessibility-internal.h
+
+// CHECK-LABEL: @interface A_Public{{$}}
+// CHECK-INTERNAL-NEXT: init
+// CHECK-NEXT: @end
+@objc public class A_Public {}
+
+// CHECK-PUBLIC-NOT: B_Internal
+// CHECK-INTERNAL-LABEL: @interface B_Internal{{$}}
+// CHECK-INTERNAL-NEXT: init
+// CHECK-INTERNAL-NEXT: @end
+@objc internal class B_Internal {}
+
+// CHECK-NOT: C_Private
+@objc private class C_Private {}

test/PrintAsObjC/blocks.swift

@@ -3,7 +3,7 @@
 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -emit-module -o %t %s
-// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/blocks.swiftmodule -parse -emit-objc-header-path %t/blocks.h
+// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/blocks.swiftmodule -parse -emit-objc-header-path %t/blocks.h -import-objc-header %S/../Inputs/empty.h
 // RUN: FileCheck %s < %t/blocks.h
 // RUN: %check-in-clang %t/blocks.h
 

test/PrintAsObjC/classes.swift

@@ -3,7 +3,7 @@
 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -enable-source-import -emit-module -o %t  %s
-// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/classes.swiftmodule -parse -emit-objc-header-path %t/classes.h
+// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/classes.swiftmodule -parse -emit-objc-header-path %t/classes.h -import-objc-header %S/../Inputs/empty.h
 // RUN: FileCheck %s < %t/classes.h
 // RUN: FileCheck --check-prefix=NEGATIVE %s < %t/classes.h
 // RUN: %check-in-clang %t/classes.h

test/PrintAsObjC/comments.swift

@@ -3,7 +3,7 @@
 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -enable-source-import -emit-module -emit-module-path %t/comments.swiftmodule -emit-module-doc -emit-module-doc-path %t/comments.swiftdoc -module-name comments %S/../Inputs/comment_to_something_conversion.swift
-// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/comments.swiftmodule -parse -emit-objc-header-path %t/comments.h
+// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/comments.swiftmodule -parse -emit-objc-header-path %t/comments.h -import-objc-header %S/../Inputs/empty.h
 // RUN: sed -n -e '/A000/,$ p' %t/comments.h > %t/comments.h-cleaned
 // RUN: diff %t/comments.h-cleaned %S/Inputs/comments-expected-output.h
 // RUN: %check-in-clang %t/comments.h

test/PrintAsObjC/extensions.swift

@@ -3,7 +3,7 @@
 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -emit-module -o %t %s
-// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/extensions.swiftmodule -parse -emit-objc-header-path %t/extensions.h
+// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/extensions.swiftmodule -parse -emit-objc-header-path %t/extensions.h -import-objc-header %S/../Inputs/empty.h
 // RUN: FileCheck %s < %t/extensions.h
 // RUN: FileCheck --check-prefix=NEGATIVE %s < %t/extensions.h
 // RUN: %check-in-clang %t/extensions.h

test/PrintAsObjC/local-types.swift

@@ -3,7 +3,7 @@
 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -emit-module -o %t %s -module-name local
-// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/local.swiftmodule -parse -emit-objc-header-path %t/local.h
+// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/local.swiftmodule -parse -emit-objc-header-path %t/local.h -import-objc-header %S/../Inputs/empty.h
 // RUN: FileCheck %s < %t/local.h
 // RUN: %check-in-clang %t/local.h
 

test/PrintAsObjC/mixed-framework-fwd.swift

@@ -29,8 +29,8 @@
 
 import Foundation
 
-class Dummy: NSNumber {
+public class Dummy: NSNumber {
-  func getProto() -> CustomProto? {
+  public func getProto() -> CustomProto? {
     return nil
   }
 }

test/PrintAsObjC/mixed-framework.swift

@@ -19,8 +19,8 @@
 
 import Foundation
 
-class Dummy: NSNumber {
+public class Dummy: NSNumber {
-  func getIntAlias() -> CIntAlias {
+  public func getIntAlias() -> CIntAlias {
     let result: CInt = 0
     return result
   }

test/PrintAsObjC/protocols.swift

@@ -3,7 +3,7 @@
 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -emit-module -o %t %s
-// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/protocols.swiftmodule -parse -emit-objc-header-path %t/protocols.h
+// RUN: %swift %clang-importer-sdk -module-cache-path %t/clang-module-cache -parse-as-library %t/protocols.swiftmodule -parse -emit-objc-header-path %t/protocols.h -import-objc-header %S/../Inputs/empty.h
 // RUN: FileCheck %s < %t/protocols.h
 // RUN: FileCheck --check-prefix=NEGATIVE %s < %t/protocols.h
 // RUN: %check-in-clang %t/protocols.h

tools/driver/frontend_main.cpp

@@ -97,7 +97,9 @@ static bool printAsObjC(const std::string &path, Module *M,
     return true;
   }
 
-  return printAsObjC(out, M, bridgingHeader);
+  auto requiredAccess = bridgingHeader.empty() ? Accessibility::Public
+                                               : Accessibility::Internal;
+  return printAsObjC(out, M, bridgingHeader, requiredAccess);
 }
 
 /// Performs the compile requested by the user.

utils/buildbot-release-notes.txt

@@ -12,6 +12,10 @@ Latest
   The general principle is that an entity cannot be defined in terms of another
   entity with less accessibility.
 
+  Along with this, the generated header for a framework will only include
+  public declarations. Generated headers for applications will include public
+  and internal declarations.
+
 * CGFloat is now a distinct floating-point type that wraps either a
   Float (on 32-bit architectures) or a Double (on 64-bit
   architectures). It provides all of the same comparison and