Merge pull request swiftlang#35665 from beccadax/i-have-some-notes-for-you

Add support for access notes

Author: beccadax

include/swift/AST/AccessNotes.h

@@ -0,0 +1,111 @@
+//===--- AccessNotes.h - Access Notes ---------------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2021 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
+//
+//===----------------------------------------------------------------------===//
+//
+//  Implements access notes, which allow certain modifiers or attributes to be
+//  added to the declarations in a module.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef ACCESSNOTES_H
+#define ACCESSNOTES_H
+
+#include "swift/AST/Identifier.h"
+#include "swift/AST/StorageImpl.h"
+#include "swift/Basic/NullablePtr.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include <set>
+#include <string>
+#include <vector>
+
+namespace swift {
+class ASTContext;
+class ValueDecl;
+
+/// The name of the declaration an access note should be applied to.
+///
+/// Grammatically, this is equivalent to a \c ParsedDeclName, but supports a
+/// subset of that type's features.
+class AccessNoteDeclName {
+public:
+  /// The names of the parent/contextual declarations containing the declaration
+  /// the access note should apply to.
+  std::vector<Identifier> parentNames;
+
+  /// The name of the declaration the access note should be applied to. (For
+  /// accessors, this is actually the name of the storage it's attached to.)
+  DeclName name;
+
+  /// For accessors, the kind of accessor; for non-accessors, \c None.
+  Optional<AccessorKind> accessorKind;
+
+  AccessNoteDeclName(ASTContext &ctx, StringRef str);
+  AccessNoteDeclName();
+
+  /// If true, an access note with this name should apply to \p VD.
+  bool matches(ValueDecl *VD) const;
+
+  /// If true, the name is empty and invalid.
+  bool empty() const;
+
+  void print(llvm::raw_ostream &os) const;
+  SWIFT_DEBUG_DUMP;
+};
+
+/// An individual access note specifying modifications to a declaration.
+class AccessNote {
+public:
+  /// The name of the declaration to modify.
+  AccessNoteDeclName Name;
+
+  /// If \c true, add an @objc attribute; if \c false, delete an @objc
+  /// attribute; if \c None, do nothing.
+  Optional<bool> ObjC;
+
+  /// If \c true, add a dynamic modifier; if \c false, delete a dynamic
+  /// modifier; if \c None, do nothing.
+  Optional<bool> Dynamic;
+
+  /// If set, modify an @objc attribute to give it the specified \c ObjCName.
+  /// If \c ObjC would otherwise be \c None, it will be set to \c true.
+  Optional<ObjCSelector> ObjCName;
+
+  void dump(llvm::raw_ostream &os, int indent = 0) const;
+  SWIFT_DEBUG_DUMP;
+};
+
+/// A set of access notes with module-wide metadata about them.
+class AccessNotesFile {
+public:
+  /// A human-readable string describing why the access notes are being applied.
+  /// Inserted into diagnostics about access notes in the file.
+  std::string Reason;
+
+  /// Access notes to apply to the module.
+  std::vector<AccessNote> Notes;
+
+  /// Load the access notes from \p buffer, or \c None if they cannot be loaded.
+  /// Diagnoses any parsing issues with the access notes file.
+  static llvm::Optional<AccessNotesFile>
+      load(ASTContext &ctx, const llvm::MemoryBuffer *buffer);
+
+  /// Look up the access note in this file, if any, which applies to \p VD.
+  NullablePtr<const AccessNote> lookup(ValueDecl *VD) const;
+
+  void dump(llvm::raw_ostream &os) const;
+  SWIFT_DEBUG_DUMP;
+};
+
+}
+
+#endif

include/swift/AST/DiagnosticsFrontend.def

@@ -405,5 +405,16 @@ WARNING(module_incompatible_with_skip_function_bodies,none,
         "-experimental-skip-*-function-bodies* flags; they have "
         "been automatically disabled", (StringRef))
 
+WARNING(access_notes_file_io_error,none,
+        "ignored access notes file at '%0' because it cannot be read: %1",
+        (StringRef, StringRef))
+WARNING(error_in_access_notes_file,none,
+        "ignored access notes file because it cannot be parsed: %0",
+        (StringRef))
+REMARK(warning_in_access_notes_file,none,
+       "ignored invalid content in access notes file: %0",
+       (StringRef))
+
+
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

include/swift/AST/DiagnosticsSema.def

@@ -5653,5 +5653,35 @@ ERROR(atomics_ordering_must_be_constant, none,
       "ordering argument must be a static method or property of %0",
       (Identifier))
 
+//------------------------------------------------------------------------------
+// MARK: access notes
+//------------------------------------------------------------------------------
+
+REMARK(attr_added_by_access_note, none,
+       "access note for %0 adds %select{attribute|modifier}1 '%2' to this %3",
+       (StringRef, bool, StringRef, DescriptiveDeclKind))
+NOTE(fixit_attr_added_by_access_note, none,
+     "add %select{attribute|modifier}0 explicitly to silence this warning",
+     (bool))
+
+REMARK(attr_removed_by_access_note, none,
+       "access note for %0 removes %select{attribute|modifier}1 '%2' from "
+       "this %3",
+       (StringRef, bool, StringRef, DescriptiveDeclKind))
+NOTE(fixit_attr_removed_by_access_note, none,
+     "remove %select{attribute|modifier}0 explicitly to silence this warning",
+     (bool))
+
+REMARK(attr_objc_name_changed_by_access_note, none,
+        "access note for %0 changes the '@objc' name of this %1 to %2",
+        (StringRef, DescriptiveDeclKind, ObjCSelector))
+NOTE(fixit_attr_objc_name_changed_by_access_note, none,
+     "change '@objc' name in source code explicitly to silence this warning",
+     ())
+REMARK(attr_objc_name_conflicts_with_access_note, none,
+       "access note for %0 changes the '@objc' name of this %1 to %2, but "
+       "source code specifies %3; the access note will be ignored",
+       (StringRef, DescriptiveDeclKind, ObjCSelector, ObjCSelector))
+
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

include/swift/AST/Identifier.h

@@ -820,6 +820,13 @@ class ObjCSelector {
   /// Construct an invalid ObjCSelector.
   ObjCSelector() : Storage() {}
 
+  /// Split \p string into selector pieces on colons to create an ObjCSelector.
+  ///
+  /// This should not be used to parse selectors written directly in Swift
+  /// source source code (e.g. the argument of an @objc attribute). Use the
+  /// parser for that.
+  static llvm::Optional<ObjCSelector> parse(ASTContext &ctx, StringRef string);
+
   /// Convert to true if the decl name is valid.
   explicit operator bool() const { return (bool)Storage; }
 

include/swift/AST/Module.h

@@ -17,6 +17,7 @@
 #ifndef SWIFT_MODULE_H
 #define SWIFT_MODULE_H
 
+#include "swift/AST/AccessNotes.h"
 #include "swift/AST/Decl.h"
 #include "swift/AST/DeclContext.h"
 #include "swift/AST/Identifier.h"
@@ -249,6 +250,8 @@ class ModuleDecl : public DeclContext, public TypeDecl {
   /// \see EntryPointInfoTy
   EntryPointInfoTy EntryPointInfo;
 
+  AccessNotesFile accessNotes;
+
   ModuleDecl(Identifier name, ASTContext &ctx, ImplicitImportInfo importInfo);
 
 public:
@@ -279,6 +282,9 @@ class ModuleDecl : public DeclContext, public TypeDecl {
   /// imports.
   ImplicitImportList getImplicitImports() const;
 
+  AccessNotesFile &getAccessNotes() { return accessNotes; }
+  const AccessNotesFile &getAccessNotes() const { return accessNotes; }
+
   ArrayRef<FileUnit *> getFiles() {
     assert(!Files.empty() || failedToLoad());
     return Files;

include/swift/AST/TypeCheckRequests.h

@@ -2312,6 +2312,25 @@ class SpecializeAttrTargetDeclRequest
   bool isCached() const { return true; }
 };
 
+/// Looks up and applies the access note for a given declaration.
+class ApplyAccessNoteRequest
+    : public SimpleRequest<ApplyAccessNoteRequest,
+                           evaluator::SideEffect(ValueDecl *),
+                           RequestFlags::Cached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  evaluator::SideEffect evaluate(Evaluator &evaluator, ValueDecl *VD) const;
+
+public:
+  // Cached.
+  bool isCached() const { return true; }
+};
+
+
 class TypeCheckSourceFileRequest
     : public SimpleRequest<
           TypeCheckSourceFileRequest, evaluator::SideEffect(SourceFile *),

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -20,6 +20,8 @@ SWIFT_REQUEST(TypeChecker, AbstractGenericSignatureRequest,
                                 SmallVector<GenericTypeParamType *, 2>,
                                 SmallVector<Requirement, 2>),
               Cached, NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, ApplyAccessNoteRequest,
+              evaluator::SideEffect(ValueDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, AttachedResultBuilderRequest,
               CustomAttr *(ValueDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, AttachedPropertyWrapperTypeRequest,

include/swift/Basic/SourceManager.h

@@ -78,7 +78,7 @@ class SourceManager {
     FileSystem = FS;
   }
 
-  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> getFileSystem() {
+  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> getFileSystem() const {
     return FileSystem;
   }
 

include/swift/Frontend/Frontend.h

@@ -467,7 +467,9 @@ class CompilerInstance {
   DiagnosticEngine &getDiags() { return Diagnostics; }
   const DiagnosticEngine &getDiags() const { return Diagnostics; }
 
-  llvm::vfs::FileSystem &getFileSystem() { return *SourceMgr.getFileSystem(); }
+  llvm::vfs::FileSystem &getFileSystem() const {
+    return *SourceMgr.getFileSystem();
+  }
 
   ASTContext &getASTContext() { return *Context; }
   const ASTContext &getASTContext() const { return *Context; }

include/swift/Frontend/FrontendOptions.h

@@ -70,6 +70,9 @@ class FrontendOptions {
   /// The path to which we should store indexing data, if any.
   std::string IndexStorePath;
 
+  /// The path to load access notes from.
+  std::string AccessNotesPath;
+
   /// The path to look in when loading a module interface file, to see if a
   /// binary module has already been built for use by the compiler.
   std::string PrebuiltModuleCachePath;