Merge pull request #1170 from tkremenek/Swift2.2-selector

[Swift 2.2] pull in SE-0022 into swift-2.2-branch.

Author: tkremenek

CHANGELOG.md

@@ -142,6 +142,29 @@ Latest
 
   For more information, see [SE-0020](https://github.com/apple/swift-evolution/blob/master/proposals/0020-if-swift-version.md).
 
+* The Objective-C selector of a Swift method can now be determined
+  directly with the #selector expression, e.g.,:
+
+      let sel = #selector(insertSubview(_:aboveSubview:)) // sel has type Selector
+
+  Along with this change, the use of string literals as selectors has
+  been deprecated, e.g.,
+
+      let sel: Selector = "insertSubview:aboveSubview:"
+
+  Generally, such string literals should be replaced with uses of
+  `#selector`, and the compiler will provide Fix-Its that use
+  `#selector`. In cases where they is not possible (e.g., when referring
+  to the getter of a property), one can still directly construct
+  selectors, e.g.,:
+
+      let sel = Selector("propertyName")
+
+  Note that the compiler is now checking the string literals used to
+  construct Selectors to ensure that they are well-formed Objective-C
+  selectors and that there is an '@objc' method with that selector.
+
+
 2015-09-17 [Xcode 7.1, Swift 2.1]
 ----------
 

docs/SIL.rst

@@ -2452,14 +2452,18 @@ string_literal
   sil-instruction ::= 'string_literal' encoding string-literal
   encoding ::= 'utf8'
   encoding ::= 'utf16'
+  encoding ::= 'objc_selector'
 
   %1 = string_literal "asdf"
   // %1 has type $Builtin.RawPointer
 
 Creates a reference to a string in the global string table. The result
 is a pointer to the data.  The referenced string is always null-terminated. The
 string literal value is specified using Swift's string
-literal syntax (though ``\()`` interpolations are not allowed).
+literal syntax (though ``\()`` interpolations are not allowed). When
+the encoding is ``objc_selector``, the string literal produces a
+reference to a UTF-8-encoded Objective-C selector in the Objective-C
+method name segment.
 
 Dynamic Dispatch
 ~~~~~~~~~~~~~~~~

include/swift/AST/DeclContext.h

@@ -405,6 +405,12 @@ class alignas(1 << DeclContextAlignInBits) DeclContext {
                        LazyResolver *typeResolver,
                        SmallVectorImpl<ValueDecl *> &decls) const;
 
+  /// Look up all Objective-C methods with the given selector visible
+  /// in the enclosing module.
+  void lookupAllObjCMethods(
+         ObjCSelector selector,
+         SmallVectorImpl<AbstractFunctionDecl *> &results) const;
+
   /// Return the ASTContext for a specified DeclContext by
   /// walking up to the enclosing module and returning its ASTContext.
   ASTContext &getASTContext() const;

include/swift/AST/DiagnosticsParse.def

@@ -1017,6 +1017,14 @@ ERROR(expected_type_after_as,none,
 ERROR(string_interpolation_extra,none,
       "extra tokens after interpolated string expression", ())
 
+// Selector expressions.
+ERROR(expr_selector_expected_lparen,PointsToFirstBadToken,
+      "expected '(' following '#selector'", ())
+ERROR(expr_selector_expected_expr,PointsToFirstBadToken,
+      "expected expression naming a method within '#selector(...)'", ())
+ERROR(expr_selector_expected_rparen,PointsToFirstBadToken,
+      "expected ')' to complete '#selector' expression", ())
+
 //------------------------------------------------------------------------------
 // Attribute-parsing diagnostics
 //------------------------------------------------------------------------------

include/swift/AST/DiagnosticsSIL.def

@@ -88,6 +88,9 @@ ERROR(unsupported_c_function_pointer_conversion,none,
       "C function pointer signature %0 is not compatible with expected type %1",
       (Type, Type))
 
+ERROR(objc_selector_malformed,none,"the type ObjectiveC.Selector is malformed",
+      ())
+
 // Definite initialization diagnostics.
 NOTE(variable_defined_here,none,
      "%select{variable|constant}0 defined here", (bool))

include/swift/AST/DiagnosticsSema.def

@@ -336,8 +336,38 @@ ERROR(noescape_functiontype_mismatch,none,
       "invalid conversion from non-escaping function of type %0 to "
       "potentially escaping function type %1", (Type, Type))
 
+// Selector expressions.
+ERROR(expr_selector_no_objc_runtime,none,
+      "'#selector' can only be used with the Objective-C runtime", ())
+ERROR(expr_selector_module_missing,none,
+      "import the 'ObjectiveC' module to use '#selector'", ())
+ERROR(expr_selector_no_declaration,none,
+      "argument of '#selector' does not refer to an initializer or method", ())
+ERROR(expr_selector_property,none,
+      "argument of '#selector' cannot refer to a property", ())
+ERROR(expr_selector_not_method_or_init,none,
+      "argument of '#selector' does not refer to a method or initializer", ())
+ERROR(expr_selector_not_objc,none,
+      "argument of '#selector' refers to %select{a method|an initializer}0 "
+      "that is not exposed to Objective-C",
+      (bool))
+NOTE(expr_selector_make_objc,none,
+     "add '@objc' to expose this %select{method|initializer}0 to Objective-C",
+     (bool))
 
-
+// Selectors-as-string-literals.
+WARNING(selector_literal_invalid,none,
+        "string literal is not a valid Objective-C selector", ())
+WARNING(selector_literal_undeclared,none,
+        "no method declared with Objective-C selector %0", (ObjCSelector))
+WARNING(selector_literal_deprecated,none,
+        "use of string literal for Objective-C selectors is deprecated; "
+        "use '#selector' or explicitly construct a 'Selector'", ())
+WARNING(selector_literal_deprecated_suggest,none,
+        "use of string literal for Objective-C selectors is deprecated; "
+        "use '#selector' instead", ())
+WARNING(selector_construction_suggest,none,
+        "use '#selector' instead of explicitly constructing a 'Selector'", ())
 
 ERROR(cannot_return_value_from_void_func,none,
       "unexpected non-void return value in void function", ())

include/swift/AST/Expr.h

@@ -3679,6 +3679,44 @@ class EditorPlaceholderExpr : public Expr {
   void setSemanticExpr(Expr *SE) { SemanticExpr = SE; }
 };
 
+/// Produces the Objective-C selector of the referenced method.
+///
+/// \code
+/// #selector(UIView.insertSubview(_:aboveSubview:))
+/// \endcode
+class ObjCSelectorExpr : public Expr {
+  SourceLoc KeywordLoc;
+  SourceLoc LParenLoc;
+  Expr *SubExpr;
+  SourceLoc RParenLoc;
+  AbstractFunctionDecl *Method = nullptr;
+
+public:
+  ObjCSelectorExpr(SourceLoc keywordLoc, SourceLoc lParenLoc,
+                   Expr *subExpr, SourceLoc rParenLoc)
+    : Expr(ExprKind::ObjCSelector, /*Implicit=*/false),
+      KeywordLoc(keywordLoc), LParenLoc(lParenLoc), SubExpr(subExpr),
+      RParenLoc(rParenLoc) { }
+
+  Expr *getSubExpr() const { return SubExpr; }
+  void setSubExpr(Expr *expr) { SubExpr = expr; }
+
+  /// Retrieve the Objective-C method to which this expression refers.
+  AbstractFunctionDecl *getMethod() const { return Method; }
+
+  /// Set the Objective-C method to which this expression refers.
+  void setMethod(AbstractFunctionDecl *method) { Method = method; }
+
+  SourceLoc getLoc() const { return KeywordLoc; }
+  SourceRange getSourceRange() const {
+    return SourceRange(KeywordLoc, RParenLoc);
+  }
+
+  static bool classof(const Expr *E) {
+    return E->getKind() == ExprKind::ObjCSelector;
+  }
+};
+
 #undef SWIFT_FORWARD_SOURCE_LOCS_TO
 
 } // end namespace swift

include/swift/AST/ExprNodes.def

@@ -155,6 +155,7 @@ EXPR(DefaultValue, Expr)
 EXPR(CodeCompletion, Expr)
 UNCHECKED_EXPR(UnresolvedPattern, Expr)
 EXPR(EditorPlaceholder, Expr)
+EXPR(ObjCSelector, Expr)
 
 #undef EXPR_RANGE
 #undef UNCHECKED_EXPR

include/swift/AST/KnownIdentifiers.def

@@ -50,6 +50,7 @@ IDENTIFIER_(OptionalNilComparisonType)
 IDENTIFIER(Protocol)
 IDENTIFIER(rawValue)
 IDENTIFIER(RawValue)
+IDENTIFIER(Selector)
 IDENTIFIER(self)
 IDENTIFIER(Self)
 IDENTIFIER(setObject)

include/swift/AST/Module.h

@@ -409,6 +409,11 @@ class ModuleDecl : public TypeDecl, public DeclContext {
                     DeclContext *container, DeclName name,
                     Identifier privateDiscriminator) const;
 
+  /// Find all Objective-C methods with the given selector.
+  void lookupObjCMethods(
+         ObjCSelector selector,
+         SmallVectorImpl<AbstractFunctionDecl *> &results) const;
+
   /// \sa getImportedModules
   enum class ImportFilter {
     All,
@@ -639,6 +644,11 @@ class FileUnit : public DeclContext {
                                  DeclName name,
                                  SmallVectorImpl<ValueDecl*> &results) const {}
 
+  /// Find all Objective-C methods with the given selector.
+  virtual void lookupObjCMethods(
+                 ObjCSelector selector,
+                 SmallVectorImpl<AbstractFunctionDecl *> &results) const = 0;
+
   /// Returns the comment attached to the given declaration.
   ///
   /// This function is an implementation detail for comment serialization.
@@ -804,6 +814,10 @@ class DerivedFileUnit final : public FileUnit {
 
   void getTopLevelDecls(SmallVectorImpl<Decl*> &results) const override;
 
+  void lookupObjCMethods(
+         ObjCSelector selector,
+         SmallVectorImpl<AbstractFunctionDecl *> &results) const override;
+
   Identifier
   getDiscriminatorForPrivateValue(const ValueDecl *D) const override {
     llvm_unreachable("no private decls in the derived file unit");
@@ -903,6 +917,11 @@ class SourceFile final : public FileUnit {
   /// complete, we diagnose.
   std::map<DeclAttrKind, const DeclAttribute *> AttrsRequiringFoundation;
 
+  /// A mapping from Objective-C selectors to the methods that have
+  /// those selectors.
+  llvm::DenseMap<ObjCSelector, llvm::TinyPtrVector<AbstractFunctionDecl *>>
+    ObjCMethods;
+
   template <typename T>
   using OperatorMap = llvm::DenseMap<Identifier,llvm::PointerIntPair<T,1,bool>>;
 
@@ -959,6 +978,10 @@ class SourceFile final : public FileUnit {
   lookupClassMember(ModuleDecl::AccessPathTy accessPath, DeclName name,
                     SmallVectorImpl<ValueDecl*> &results) const override;
 
+  void lookupObjCMethods(
+         ObjCSelector selector,
+         SmallVectorImpl<AbstractFunctionDecl *> &results) const override;
+
   virtual void getTopLevelDecls(SmallVectorImpl<Decl*> &results) const override;
 
   virtual void
@@ -1120,6 +1143,11 @@ class BuiltinUnit final : public FileUnit {
                            NLKind lookupKind,
                            SmallVectorImpl<ValueDecl*> &result) const override;
 
+  /// Find all Objective-C methods with the given selector.
+  void lookupObjCMethods(
+         ObjCSelector selector,
+         SmallVectorImpl<AbstractFunctionDecl *> &results) const override;
+
   Identifier
   getDiscriminatorForPrivateValue(const ValueDecl *D) const override {
     llvm_unreachable("no private values in the Builtin module");

include/swift/ClangImporter/ClangModule.h

@@ -73,6 +73,10 @@ class ClangModuleUnit final : public LoadedFile {
   lookupClassMember(ModuleDecl::AccessPathTy accessPath, DeclName name,
                     SmallVectorImpl<ValueDecl*> &decls) const override;
 
+  void lookupObjCMethods(
+         ObjCSelector selector,
+         SmallVectorImpl<AbstractFunctionDecl *> &results) const override;
+
   virtual void getTopLevelDecls(SmallVectorImpl<Decl*> &results) const override;
 
   virtual void getDisplayDecls(SmallVectorImpl<Decl*> &results) const override;

include/swift/Parse/Parser.h

@@ -1097,6 +1097,7 @@ class Parser {
                                               bool isExprBasic);
   ParserResult<Expr> parseExprPostfix(Diag<> ID, bool isExprBasic);
   ParserResult<Expr> parseExprUnary(Diag<> ID, bool isExprBasic);
+  ParserResult<Expr> parseExprSelector();
   ParserResult<Expr> parseExprSuper();
   ParserResult<Expr> parseExprConfiguration();
   Expr *parseExprStringLiteral();

include/swift/Parse/Token.h

@@ -44,6 +44,7 @@ enum class tok {
   pound_endif,
   pound_line,
   pound_available,
+  pound_selector,
   comment,
 
 #define KEYWORD(X) kw_ ## X,

include/swift/SIL/SILInstruction.h

@@ -1254,7 +1254,9 @@ class StringLiteralInst : public LiteralInst {
 public:
   enum class Encoding {
     UTF8,
-    UTF16
+    UTF16,
+    /// UTF-8 encoding of an Objective-C selector.
+    ObjCSelector,
   };
 
 private:

include/swift/Serialization/ModuleFile.h

@@ -553,6 +553,11 @@ class ModuleFile : public LazyMemberLoader {
                          DeclName name,
                          SmallVectorImpl<ValueDecl*> &results);
 
+  /// Find all Objective-C methods with the given selector.
+  void lookupObjCMethods(
+         ObjCSelector selector,
+         SmallVectorImpl<AbstractFunctionDecl *> &results);
+
   /// Reports all link-time dependencies.
   void collectLinkLibraries(Module::LinkLibraryCallback callback) const;
 

include/swift/Serialization/SerializedModuleLoader.h

@@ -131,6 +131,11 @@ class SerializedASTFile final : public LoadedFile {
   lookupClassMember(Module::AccessPathTy accessPath, DeclName name,
                     SmallVectorImpl<ValueDecl*> &decls) const override;
 
+  /// Find all Objective-C methods with the given selector.
+  void lookupObjCMethods(
+         ObjCSelector selector,
+         SmallVectorImpl<AbstractFunctionDecl *> &results) const override;
+
   Optional<BriefAndRawComment> getCommentForDecl(const Decl *D) const override;
 
   virtual void getTopLevelDecls(SmallVectorImpl<Decl*> &results) const override;

lib/AST/ASTDumper.cpp

@@ -2161,6 +2161,16 @@ class PrintExpr : public ExprVisitor<PrintExpr> {
     }
     OS << ')';
   }
+  void visitObjCSelectorExpr(ObjCSelectorExpr *E) {
+    printCommon(E, "objc_selector_expr") << " decl=";
+    if (auto method = E->getMethod())
+      method->dumpRef(OS);
+    else
+      OS << "<unresolved>";
+    OS << '\n';
+    printRec(E->getSubExpr());
+    OS << ')';
+  }
 };
 
 } // end anonymous namespace.

lib/AST/ASTWalker.cpp

@@ -811,6 +811,14 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
     return E;
   }
 
+  Expr *visitObjCSelectorExpr(ObjCSelectorExpr *E) {
+    Expr *sub = doIt(E->getSubExpr());
+    if (!sub) return nullptr;
+
+    E->setSubExpr(sub);
+    return E;
+  }
+
   //===--------------------------------------------------------------------===//
   //                           Everything Else
   //===--------------------------------------------------------------------===//

lib/AST/Expr.cpp

@@ -314,6 +314,7 @@ void Expr::propagateLValueAccessKind(AccessKind accessKind,
     NON_LVALUE_EXPR(Assign)
     NON_LVALUE_EXPR(DefaultValue)
     NON_LVALUE_EXPR(CodeCompletion)
+    NON_LVALUE_EXPR(ObjCSelector)
 
 #define UNCHECKED_EXPR(KIND, BASE) \
     NON_LVALUE_EXPR(KIND)
@@ -487,6 +488,7 @@ bool Expr::canAppendCallParentheses() const {
   case ExprKind::StringLiteral:
   case ExprKind::InterpolatedStringLiteral:
   case ExprKind::MagicIdentifierLiteral:
+  case ExprKind::ObjCSelector:
     return true;
 
   case ExprKind::ObjectLiteral: