[SourceKit][IDE] New SourceKit request to retrieve context type information

include/swift/AST/Decl.h

@@ -2412,6 +2412,10 @@ class ValueDecl : public Decl {
 
   bool isUsableFromInline() const;
 
+  /// Returns \c true if this declaration is *not* intended to be used directly
+  /// by application developers despite of the visibility.
+  bool shouldHideFromEditor() const;
+
   bool hasAccess() const {
     return TypeAndAccess.getInt().hasValue();
   }

include/swift/IDE/TypeContextInfo.h

@@ -0,0 +1,60 @@
+//===--- TypeContextInfo.h --------------------------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2019 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_IDE_TYPECONTEXTINFO_H
+#define SWIFT_IDE_TYPECONTEXTINFO_H
+
+#include "swift/AST/Type.h"
+#include "swift/Basic/LLVM.h"
+
+namespace swift {
+class CodeCompletionCallbacksFactory;
+
+namespace ide {
+
+/// A result item for context info query.
+class TypeContextInfoItem {
+public:
+  /// Possible expected type.
+  Type ExpectedTy;
+  /// Members of \c ExpectedTy which can be referenced by "Implicit Member
+  /// Expression".
+  SmallVector<ValueDecl *, 0> ImplicitMembers;
+
+  TypeContextInfoItem(Type ExpectedTy) : ExpectedTy(ExpectedTy) {}
+};
+
+/// An abstract base class for consumers of context info results.
+class TypeContextInfoConsumer {
+public:
+  virtual ~TypeContextInfoConsumer() {}
+  virtual void handleResults(ArrayRef<TypeContextInfoItem>) = 0;
+};
+
+/// Printing consumer
+class PrintingTypeContextInfoConsumer : public TypeContextInfoConsumer {
+  llvm::raw_ostream &OS;
+
+public:
+  PrintingTypeContextInfoConsumer(llvm::raw_ostream &OS) : OS(OS) {}
+
+  void handleResults(ArrayRef<TypeContextInfoItem>) override;
+};
+
+/// Create a factory for code completion callbacks.
+CodeCompletionCallbacksFactory *
+makeTypeContextInfoCallbacksFactory(TypeContextInfoConsumer &Consumer);
+
+} // namespace ide
+} // namespace swift
+
+#endif // SWIFT_IDE_TYPECONTEXTINFO_H

lib/AST/Decl.cpp

@@ -2550,6 +2550,34 @@ bool ValueDecl::isUsableFromInline() const {
   return false;
 }
 
+/// Returns \c true if this declaration is *not* intended to be used directly
+/// by application developers despite of the visibility.
+bool ValueDecl::shouldHideFromEditor() const {
+  // Hide private stdlib declarations.
+  if (isPrivateStdlibDecl(/*treatNonBuiltinProtocolsAsPublic*/ false) ||
+      // ShowInInterfaceAttr is for decls to show in interface as exception but
+      // they are not intended to be used directly.
+      getAttrs().hasAttribute<ShowInInterfaceAttr>())
+    return true;
+
+  if (AvailableAttr::isUnavailable(this))
+    return true;
+
+  if (auto *ClangD = getClangDecl()) {
+    if (ClangD->hasAttr<clang::SwiftPrivateAttr>())
+      return true;
+  }
+
+  if (!isUserAccessible())
+    return true;
+
+  // Hide editor placeholders.
+  if (getBaseName().isEditorPlaceholder())
+    return true;
+
+  return false;
+}
+
 /// Return the access level of an internal or public declaration
 /// that's been testably imported.
 static AccessLevel getTestableOrPrivateImportsAccess(const ValueDecl *decl) {

lib/IDE/CMakeLists.txt

@@ -2,6 +2,7 @@ add_swift_host_library(swiftIDE STATIC
   CodeCompletion.cpp
   CodeCompletionCache.cpp
   CommentConversion.cpp
+  ExprContextAnalysis.cpp
   Formatting.cpp
   Refactoring.cpp
   ModuleInterfacePrinting.cpp
@@ -13,7 +14,9 @@ add_swift_host_library(swiftIDE STATIC
   IDETypeChecking.cpp
   APIDigesterData.cpp
   SourceEntityWalker.cpp
+  TypeContextInfo.cpp
   LINK_LIBRARIES
+    swiftAST
     swiftFrontend
     swiftClangImporter
     swiftDWARFImporter