[Macro] Omnibus pull request with macro improvements

include/swift/APIDigester/ModuleAnalyzerNodes.h

@@ -674,6 +674,13 @@ class SDKNodeDeclVar : public SDKNodeDecl {
   void addAccessor(SDKNode* AC);
 };
 
+class SDKNodeDeclMacro : public SDKNodeDecl {
+public:
+  SDKNodeDeclMacro(SDKNodeInitInfo Info);
+  static bool classof(const SDKNode *N);
+  SDKNodeType *getType() const;
+};
+
 class SDKNodeDeclAbstractFunc : public SDKNodeDecl {
   bool IsThrowing;
   bool ReqNewWitnessTableEntry;
@@ -796,6 +803,7 @@ class SwiftDeclCollector: public VisibleDeclConsumer {
   SDKNode *constructSubscriptDeclNode(SubscriptDecl *SD);
   SDKNode *constructAssociatedTypeNode(AssociatedTypeDecl *ATD);
   SDKNode *constructTypeAliasNode(TypeAliasDecl *TAD);
+  SDKNode *constructMacroNode(MacroDecl *MAD);
   SDKNode *constructVarNode(ValueDecl *VD);
   SDKNode *constructExternalExtensionNode(NominalTypeDecl *NTD,
                                           ArrayRef<ExtensionDecl*> AllExts);

include/swift/AST/Decl.h

@@ -60,6 +60,7 @@ namespace swift {
   struct ASTNode;
   class ASTPrinter;
   class ASTWalker;
+  enum class BuiltinMacroKind: uint8_t;
   class ConstructorDecl;
   class DestructorDecl;
   class DiagnosticEngine;
@@ -79,6 +80,7 @@ namespace swift {
   class GenericSignature;
   class GenericTypeParamDecl;
   class GenericTypeParamType;
+  class MacroDefinition;
   class ModuleDecl;
   class NamedPattern;
   class EnumCaseDecl;
@@ -255,6 +257,9 @@ struct OverloadSignature {
   /// Whether this is a type alias.
   unsigned IsTypeAlias : 1;
 
+  /// Whether this is a macro.
+  unsigned IsMacro : 1;
+
   /// Whether this signature is part of a protocol extension.
   unsigned InProtocolExtension : 1;
 
@@ -8341,27 +8346,16 @@ class MacroDecl : public GenericContext, public ValueDecl {
   /// The result type.
   TypeLoc resultType;
 
-  /// The module name for the external macro definition.
-  Identifier externalModuleName;
-
-  /// The location of the module name for the external macro definition.
-  SourceLoc externalModuleNameLoc;
-
-  /// The type name for the external macro definition.
-  Identifier externalMacroTypeName;
-
-  /// The location of the type name for the external macro definition.
-  SourceLoc externalMacroTypeNameLoc;
+  /// The macro definition, which should always be a
+  /// \c MacroExpansionExpr in well-formed code.
+  Expr *definition;
 
   MacroDecl(SourceLoc macroLoc, DeclName name, SourceLoc nameLoc,
             GenericParamList *genericParams,
             ParameterList *parameterList,
             SourceLoc arrowOrColonLoc,
             TypeRepr *resultType,
-            Identifier externalModuleName,
-            SourceLoc externalModuleNameLoc,
-            Identifier externalMacroTypeName,
-            SourceLoc externalMacroTypeNameLoc,
+            Expr *definition,
             DeclContext *parent);
 
   SourceRange getSourceRange() const;
@@ -8372,6 +8366,13 @@ class MacroDecl : public GenericContext, public ValueDecl {
   /// Determine the contexts in which this macro can be applied.
   MacroContexts getMacroContexts() const;
 
+  /// Retrieve the definition of this macro.
+  MacroDefinition getDefinition() const;
+
+  /// Retrieve the builtin macro kind for this macro, or \c None if it is a
+  /// user-defined macro with no special semantics.
+  Optional<BuiltinMacroKind> getBuiltinKind() const;
+
   static bool classof(const DeclContext *C) {
     if (auto D = C->getAsDecl())
       return classof(D);

include/swift/AST/DiagnosticsCommon.def

@@ -219,6 +219,8 @@ ERROR(unknown_attribute,none,
 //------------------------------------------------------------------------------
 NOTE(in_macro_expansion,none,
      "in expansion of macro %0 here", (DeclName))
+ERROR(macro_experimental,none,
+      "macros are an experimental feature that is not enabled", ())
 
 //------------------------------------------------------------------------------
 // MARK: bridged diagnostics

include/swift/AST/DiagnosticsParse.def

@@ -1329,9 +1329,6 @@ ERROR(expected_rsquare_array_expr,PointsToFirstBadToken,
 // Object literal expressions
 ERROR(expected_arg_list_in_object_literal,PointsToFirstBadToken,
       "expected argument list in object literal", ())
-ERROR(legacy_object_literal,none,
-      "'%select{|[}0#%1(...)%select{|#]}0' has been renamed to '#%2(...)'",
-      (bool, StringRef, StringRef))
 
 // Unknown pound expression.
 ERROR(unknown_pound_expr,none,
@@ -1999,18 +1996,12 @@ ERROR(expected_lparen_macro,PointsToFirstBadToken,
       "expected '(' for macro parameters or ':' for a value-like macro", ())
 ERROR(expected_type_macro_result,PointsToFirstBadToken,
       "expected macro result type", ())
-ERROR(macro_decl_expected_equal,PointsToFirstBadToken,
-      "expected '=' to introduce external macro name", ())
-ERROR(macro_decl_expected_macro_module,PointsToFirstBadToken,
-      "expected external macro name", ())
-ERROR(macro_decl_expected_period,PointsToFirstBadToken,
-      "expected '.' between external macro module and type name", ())
-ERROR(macro_decl_expected_macro_type,PointsToFirstBadToken,
-      "expected external macro type name", ())
-
-ERROR(macro_expansion_expr_expected_macro_identifier,none,
+ERROR(macro_decl_expected_macro_definition,PointsToFirstBadToken,
+      "expected macro definition following '=''", ())
+
+ERROR(macro_expansion_expr_expected_macro_identifier,PointsToFirstBadToken,
       "expected a macro identifier for a pound literal expression", ())
-ERROR(macro_expansion_decl_expected_macro_identifier,none,
+ERROR(macro_expansion_decl_expected_macro_identifier,PointsToFirstBadToken,
       "expected a macro identifier for a pound literal declaration", ())
 
 ERROR(parser_round_trip_error,none,

include/swift/AST/DiagnosticsSema.def

@@ -1271,15 +1271,18 @@ ERROR(missing_init_on_metatype_initialization,none,
       "initializing from a metatype value must reference 'init' explicitly",
       ())
 ERROR(extra_argument_labels,none,
-      "extraneous argument label%select{|s}0 '%1' in %select{call|subscript}2",
-      (bool, StringRef, bool))
+      "extraneous argument label%select{|s}0 '%1' in "
+      "%select{call|subscript|macro expansion}2",
+      (bool, StringRef, unsigned))
 ERROR(missing_argument_labels,none,
-      "missing argument label%select{|s}0 '%1' in %select{call|subscript}2",
-      (bool, StringRef, bool))
+      "missing argument label%select{|s}0 '%1' in "
+      "%select{call|subscript|macro expansion}2",
+      (bool, StringRef, unsigned))
 ERROR(wrong_argument_labels,none,
-      "incorrect argument label%select{|s}0 in %select{call|subscript}3 "
+      "incorrect argument label%select{|s}0 in "
+      "%select{call|subscript|macro expansion}3 "
       "(have '%1', expected '%2')",
-      (bool, StringRef, StringRef, bool))
+      (bool, StringRef, StringRef, unsigned))
 ERROR(argument_out_of_order_named_named,none,
       "argument %0 must precede argument %1", (Identifier, Identifier))
 ERROR(argument_out_of_order_named_unnamed,none,
@@ -1313,22 +1316,29 @@ ERROR(instance_member_in_default_parameter,none,
       "cannot use instance member %0 as a default parameter", (DeclNameRef))
 
 ERROR(missing_argument_named,none,
-      "missing argument for parameter %0 in call", (Identifier))
+      "missing argument for parameter %0 in "
+      "%select{call|subscript|macro expansion}1", (Identifier, unsigned))
 ERROR(missing_argument_positional,none,
-      "missing argument for parameter #%0 in call", (unsigned))
+      "missing argument for parameter #%0 in "
+      "%select{call|subscript|macro expansion}1", (unsigned, unsigned))
 ERROR(missing_arguments_in_call,none,
-      "missing arguments for parameters %0 in call", (StringRef))
+      "missing arguments for parameters %0 in "
+      "%select{call|subscript|macro expansion}1", (StringRef, unsigned))
 ERROR(extra_argument_named,none,
-      "extra argument %0 in call", (Identifier))
+      "extra argument %0 in %select{call|subscript|macro expansion}1",
+       (Identifier, unsigned))
 ERROR(extra_argument_positional,none,
-      "extra argument in call", ())
+      "extra argument in %select{call|subscript|macro expansion}0",
+      (unsigned))
 ERROR(extra_arguments_in_call,none,
       "extra %select{arguments|trailing closures}0 at positions %1 in call",
        (bool, StringRef))
 ERROR(extra_argument_to_nullary_call,none,
-      "argument passed to call that takes no arguments", ())
+      "argument passed to %select{call|subscript|macro expansion}0 "
+      "that takes no arguments", (unsigned))
 ERROR(extra_trailing_closure_in_call,none,
-      "extra trailing closure passed in call", ())
+      "extra trailing closure passed in "
+      "%select{call|subscript|macro expansion}0", (unsigned))
 ERROR(trailing_closure_bad_param,none,
       "trailing closure passed to parameter of type %0 that does not "
       "accept a closure", (Type))
@@ -6752,8 +6762,7 @@ ERROR(experimental_no_metadata_feature_can_only_be_used_when_enabled,
 ERROR(expected_macro_expansion_expr,PointsToFirstBadToken,
       "expected macro expansion to produce an expression", ())
 ERROR(macro_undefined,PointsToFirstBadToken,
-      "macro %0 is undefined; use `-load-plugin-library` to specify dynamic "
-      "libraries that contain this macro", (Identifier))
+      "no macro named %0", (Identifier))
 ERROR(external_macro_not_found,none,
       "external macro implementation type '%0.%1' could not be found for "
       "macro %2; the type must be public and provided via "
@@ -6784,6 +6793,26 @@ ERROR(macro_in_nested,none,
 ERROR(macro_without_context,none,
       "macro %0 must declare its applicable contexts (e.g., '@expression')",
        (DeclName))
+ERROR(macro_expansion_missing_pound,none,
+      "expansion of macro %0 requires leading '#'", (DeclName))
+ERROR(macro_expansion_missing_arguments,none,
+      "expansion of macro %0 requires arguments", (DeclName))
+ERROR(macro_unsupported,none,
+      "macros are not supported in this compiler", ())
+ERROR(macro_recursive,none,
+      "recursive expansion of macro %0", (DeclName))
+WARNING(macro_definition_old_style,none,
+        "external macro definitions are now written using #externalMacro", ())
+WARNING(macro_definition_unknown_builtin,none,
+        "ignoring definition of unknown builtin macro %0", (Identifier))
+ERROR(macro_definition_not_expansion,none,
+      "macro must itself be defined by a macro expansion such as "
+      "'#externalMacro(...)'", ())
+ERROR(macro_definition_unsupported,none,
+      "macro definitions other than '#externalMacro(...)' are unsupported", ())
+ERROR(external_macro_arg_not_type_name,none,
+      "argument to `#externalMacro` must be a string literal naming "
+      "the external macro's %select{module|type}", (unsigned))
 
 //------------------------------------------------------------------------------
 // MARK: Move Only Errors

include/swift/AST/MacroDefinition.h

@@ -22,64 +22,97 @@
 
 namespace swift {
 
+/// A reference to an external macro definition that is understood by ASTGen.
+struct ExternalMacroDefinition {
+  /// ASTGen's notion of an macro definition, which is opaque to the C++ part
+  /// of the compiler.
+  void *opaqueHandle = nullptr;
+};
+
+/// A reference to an external macro.
+struct ExternalMacroReference {
+  Identifier moduleName;
+  Identifier macroTypeName;
+};
+
+/// Describes the known kinds of builtin macros.
+enum class BuiltinMacroKind: uint8_t {
+  /// #externalMacro, which references an external macro.
+  ExternalMacro,
+};
+
 /// Provides the definition of a macro.
 class MacroDefinition {
 public:
-  /// Describes a missing macro definition.
-  struct MissingDefinition {
-    Identifier externalModuleName;
-    Identifier externalMacroTypeName;
-  };
-
     /// Describes how the macro is implemented.
-  enum class ImplementationKind: uint8_t {
+  enum class Kind: uint8_t {
+    /// The macro has a definition, but it is invalid, so the macro cannot be
+    /// expanded.
+    Invalid,
+
     /// The macro has no definition.
     Undefined,
 
-    /// The macro has a definition, but it could not be found.
-    Missing,
+    /// An externally-provided macro definition.
+    External,
 
-    /// The macro is in the same process as the compiler, whether built-in or
-    /// loaded via a compiler plugin.
-    InProcess,
+    /// A builtin macro definition, which has a separate builtin kind.
+    Builtin,
   };
 
-  ImplementationKind implKind;
+  Kind kind;
 
 private:
-  void *opaqueHandle;
+  union Data {
+    ExternalMacroReference external;
+    BuiltinMacroKind builtin;
 
-  MacroDefinition(ImplementationKind implKind, void *opaqueHandle)
-    : implKind(implKind), opaqueHandle(opaqueHandle) { }
+    Data() : builtin(BuiltinMacroKind::ExternalMacro) { }
+  } data;
+
+  MacroDefinition(Kind kind) : kind(kind) { }
+
+  MacroDefinition(ExternalMacroReference external) : kind(Kind::External) {
+    data.external = external;
+  }
+
+  MacroDefinition(BuiltinMacroKind builtinKind) : kind(Kind::Builtin) {
+    data.builtin = builtinKind;
+  }
 
 public:
+  static MacroDefinition forInvalid() {
+    return MacroDefinition(Kind::Invalid);
+  }
+
   static MacroDefinition forUndefined() {
-    return MacroDefinition{
-      ImplementationKind::Undefined, nullptr
-    };
+    return MacroDefinition(Kind::Undefined);
   }
 
-  static MacroDefinition forMissing(
-      ASTContext &ctx,
-      Identifier externalModuleName,
-      Identifier externalMacroTypeName
-  );
+  static MacroDefinition forExternal(
+      Identifier moduleName,
+      Identifier macroTypeName
+   ) {
+    return MacroDefinition(ExternalMacroReference{moduleName, macroTypeName});
+  }
 
-  static MacroDefinition forInProcess(void *opaqueHandle) {
-    return MacroDefinition{ImplementationKind::InProcess, opaqueHandle};
+  static MacroDefinition forBuiltin(BuiltinMacroKind builtinKind) {
+    return MacroDefinition(builtinKind);
   }
 
-  /// Return the opaque handle for an in-process macro definition.
-  void *getInProcessOpaqueHandle() const {
-    assert(implKind == ImplementationKind::InProcess);
-    return opaqueHandle;
+  /// Retrieve the external macro being referenced.
+  ExternalMacroReference getExternalMacro() const {
+    assert(kind == Kind::External);
+    return data.external;
   }
 
-  /// Return more information about a missing macro definition.
-  MissingDefinition *getMissingDefinition() const {
-    assert(implKind == ImplementationKind::Missing);
-    return static_cast<MissingDefinition *>(opaqueHandle);
+  /// Retrieve the builtin kind.
+  BuiltinMacroKind getBuiltinKind() const {
+    assert(kind == Kind::Builtin);
+    return data.builtin;
   }
+
+  explicit operator bool() const { return kind != Kind::Invalid; }
 };
 
 }