Merge pull request #62204 from DougGregor/macro-declarations

Macro declarations

Author: DougGregor

docs/ABI/Mangling.rst

@@ -362,6 +362,7 @@ Entities
   entity-spec ::= decl-name label-list? type 'v' ACCESSOR                           // variable
   entity-spec ::= decl-name type 'fp'                                               // generic type parameter
   entity-spec ::= decl-name type 'fo'                                               // enum element (currently not used)
+  entity-spec ::= decl-name label-list? type generic-signature? 'fm'   // macro
   entity-spec ::= identifier 'Qa'                                                   // associated type declaration
 
   ACCESSOR ::= 'm'                           // materializeForSet

include/swift/AST/ASTContext.h

@@ -1439,12 +1439,6 @@ class ASTContext final {
   /// The declared interface type of Builtin.TheTupleType.
   BuiltinTupleType *getBuiltinTupleType();
 
-  /// Finds the loaded compiler plugins with the given name.
-  TinyPtrVector<CompilerPlugin *> getLoadedPlugins(StringRef name);
-
-  /// Add a loaded plugin with the given name.
-  void addLoadedPlugin(StringRef name, CompilerPlugin *plugin);
-
   /// Finds the address of the given symbol. If `libraryHandleHint` is non-null,
   /// search within the library.
   void *getAddressOfSymbol(const char *name, void *libraryHandleHint = nullptr);

include/swift/AST/ASTScope.h

@@ -1187,6 +1187,35 @@ class EnumElementScope : public ASTScopeImpl {
   void expandAScopeThatDoesNotCreateANewInsertionPoint(ScopeCreator &);
 };
 
+class MacroDeclScope final : public ASTScopeImpl {
+public:
+  MacroDecl *const decl;
+
+  MacroDeclScope(MacroDecl *e) : decl(e) {}
+  virtual ~MacroDeclScope() {}
+
+protected:
+  ASTScopeImpl *expandSpecifically(ScopeCreator &scopeCreator) override;
+
+private:
+  void expandAScopeThatDoesNotCreateANewInsertionPoint(ScopeCreator &);
+
+public:
+  std::string getClassName() const override;
+  SourceRange
+  getSourceRangeOfThisASTNode(bool omitAssertions = false) const override;
+
+protected:
+  void printSpecifics(llvm::raw_ostream &out) const override;
+
+public:
+  virtual NullablePtr<Decl> getDeclIfAny() const override { return decl; }
+  Decl *getDecl() const { return decl; }
+
+protected:
+  NullablePtr<const GenericParamList> genericParams() const override;
+};
+
 class AbstractStmtScope : public ASTScopeImpl {
 public:
   SourceRange

include/swift/AST/CompilerPlugin.h

@@ -54,21 +54,10 @@ class CompilerPlugin {
   // stdlib/toolchain/CompilerPluginSupport.swift.
   enum class WitnessTableEntry: unsigned {
     ConformanceDescriptor = 0,
-    // static func _name() -> (UnsafePointer<UInt8>, count: Int8)
-    Name = 1,
     // static func _kind() -> _CompilerPluginKind
-    Kind = 2,
+    Kind = 1,
     // static func _rewrite(...) -> (UnsafePointer<UInt8>?, count: Int)
-    Rewrite = 3,
-    // static func _genericSignature(...) -> (UnsafePointer<UInt8>?, count: Int)
-    GenericSignature = 4,
-    // static func _typeSignature(...) -> (UnsafePointer<UInt8>, count: Int)
-    TypeSignature = 5,
-    // static func _owningModule(...) -> (UnsafePointer<UInt8>, count: Int)
-    OwningModule = 6,
-    // static func _supplementalSignatureModules(...)
-    //     -> (UnsafePointer<UInt8>, count: Int)
-    SupplementalSignatureModules = 7,
+    Rewrite = 2,
   };
 
   /// The plugin type metadata.
@@ -77,8 +66,6 @@ class CompilerPlugin {
   void *parentLibrary;
   /// The witness table proving that the plugin conforms to `_CompilerPlugin`.
   const void *witnessTable;
-  /// The plugin name, aka. result of the `_name()` method.
-  StringRef name;
   /// The plugin's kind, aka. result of the `_kind()` method.
   Kind kind;
 
@@ -87,14 +74,10 @@ class CompilerPlugin {
     return reinterpret_cast<const Func *const *>(witnessTable)[(unsigned)entry];
   }
 
-protected:
-  CompilerPlugin(const void *metadata, void *parentLibrary, ASTContext &ctx);
+  CompilerPlugin(
+      const void *metadata, void *parentLibrary, const void *witnessTable);
 
 private:
-  /// Invoke the `_name` method. The caller assumes ownership of the result
-  /// string buffer.
-  StringRef invokeName() const;
-
   /// Invoke the `_kind` method.
   Kind invokeKind() const;
 
@@ -103,33 +86,16 @@ class CompilerPlugin {
   CompilerPlugin(const CompilerPlugin &) = delete;
   CompilerPlugin(CompilerPlugin &&) = default;
 
+  /// Try to resolve a compiler plugin given the metadata point.
+  static CompilerPlugin *fromMetatype(const void *metadata, ASTContext &ctx);
+
   /// Invoke the `_rewrite` method. The caller assumes ownership of the result
   /// string buffer and diagnostic buffers.
   Optional<NullTerminatedStringRef> invokeRewrite(
       StringRef targetModuleName, StringRef filePath, StringRef sourceFileText,
       CharSourceRange range, ASTContext &ctx,
       SmallVectorImpl<Diagnostic> &diagnostics) const;
 
-  /// Invoke the `_genericSignature` method. The caller assumes ownership of the
-  /// result string buffer.
-  Optional<StringRef> invokeGenericSignature() const;
-
-  /// Invoke the `_typeSignature` method. The caller assumes ownership of the
-  /// result string buffer.
-  StringRef invokeTypeSignature() const;
-
-  /// Invoke the `_owningModule` method. The caller assumes ownership of the
-  /// result string buffer.
-  StringRef invokeOwningModule() const;
-
-  /// Invoke the `_supplementalSignatureModules` method. The caller assumes
-  /// ownership of the result string buffer.
-  StringRef invokeSupplementalSignatureModules() const;
-
-  StringRef getName() const {
-    return name;
-  }
-
   Kind getKind() const {
     return kind;
   }

include/swift/AST/Decl.h

@@ -8280,44 +8280,47 @@ class MissingMemberDecl : public Decl {
 /// representation in the source code, but are still declarations.
 class MacroDecl : public GenericContext, public ValueDecl {
 public:
-  /// The kind of macro, which determines how it can be used in source code.
-  enum Kind: uint8_t {
-    /// An expression macro.
-    Expression,
-  };
+  /// The location of the 'macro' keyword.
+  SourceLoc macroLoc;
 
-  /// Describes how the macro is implemented.
-  enum class ImplementationKind: uint8_t {
-    /// The macro is built-in to the compiler, linked against the same
-    /// underlying syntax tree libraries.
-    Builtin,
+  /// The parameter list for a function-like macro.
+  ParameterList *parameterList;
 
-    /// The macro was defined in a compiler plugin.
-    Plugin,
-  };
+  /// Where the '->' or ':' is located, for a function- or value-like macro,
+  /// respectively.
+  SourceLoc arrowOrColonLoc;
 
-  /// The kind of macro.
-  const Kind kind;
+  /// The result type.
+  TypeLoc resultType;
 
-  /// How the macro is implemented.
-  const ImplementationKind implementationKind;
+  /// The module name for the external macro definition.
+  Identifier externalModuleName;
 
-  /// Supplemental modules that should be imported when
-  const ArrayRef<ModuleDecl *> supplementalSignatureModules;
+  /// The location of the module name for the external macro definition.
+  SourceLoc externalModuleNameLoc;
 
-  /// An opaque handle to the representation of the macro.
-  void * const opaqueHandle;
+  /// The type name for the external macro definition.
+  Identifier externalMacroTypeName;
 
-public:
-  MacroDecl(
-    Kind kind, ImplementationKind implementationKind, Identifier name,
-    ModuleDecl *owningModule,
-    ArrayRef<ModuleDecl *> supplementalSignatureModules,
-    void *opaqueHandle
-  );
+  /// The location of the type name for the external macro definition.
+  SourceLoc externalMacroTypeNameLoc;
+
+  MacroDecl(SourceLoc macroLoc, DeclName name, SourceLoc nameLoc,
+            GenericParamList *genericParams,
+            ParameterList *parameterList,
+            SourceLoc arrowOrColonLoc,
+            TypeRepr *resultType,
+            Identifier externalModuleName,
+            SourceLoc externalModuleNameLoc,
+            Identifier externalMacroTypeName,
+            SourceLoc externalMacroTypeNameLoc,
+            DeclContext *parent);
 
   SourceRange getSourceRange() const;
 
+  /// Retrieve the interface type produced when expanding this macro.
+  Type getResultInterfaceType() const;
+
   static bool classof(const DeclContext *C) {
     if (auto D = C->getAsDecl())
       return classof(D);
@@ -8481,6 +8484,8 @@ inline bool ValueDecl::hasCurriedSelf() const {
 inline bool ValueDecl::hasParameterList() const {
   if (auto *eed = dyn_cast<EnumElementDecl>(this))
     return eed->hasAssociatedValues();
+  if (auto *macro = dyn_cast<MacroDecl>(this))
+    return macro->parameterList != nullptr;
   return isa<AbstractFunctionDecl>(this) || isa<SubscriptDecl>(this);
 }
 

include/swift/AST/DeclContext.h

@@ -94,14 +94,14 @@ enum class DeclContextKind : unsigned {
   EnumElementDecl,
   AbstractFunctionDecl,
   SerializedLocal,
-  Last_LocalDeclContextKind = SerializedLocal,
+  MacroDecl,
+  Last_LocalDeclContextKind = MacroDecl,
 
   Module,
   FileUnit,
   GenericTypeDecl,
   ExtensionDecl,
-  MacroDecl,
-  Last_DeclContextKind = MacroDecl
+  Last_DeclContextKind = ExtensionDecl
 };
 
 /// Kinds of DeclContexts after deserialization.

include/swift/AST/DiagnosticsFrontend.def

@@ -478,10 +478,6 @@ REMARK(warning_in_access_notes_file,none,
 
 WARNING(compiler_plugin_not_loaded,none,
         "compiler plugin not loaded: %0; loader error: %1", (StringRef, StringRef))
-WARNING(compiler_plugin_missing_macro_declaration,none,
-        "compiler plugin module '%0' (in %1) is missing a top-level computed "
-        "property 'public var %2: [Any.Type]' to declare all macros; "
-        "undeclared macros will be ignored", (StringRef, StringRef, StringRef))
 
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

include/swift/AST/DiagnosticsParse.def

@@ -1999,8 +1999,24 @@ ERROR(foreign_diagnostic,none,
       "%0", (StringRef))
 
 //------------------------------------------------------------------------------
-// MARK: macro expansion
+// MARK: macros
 //------------------------------------------------------------------------------
+ERROR(expected_macro_value_type,PointsToFirstBadToken,
+      "expected macro value type following ':'", ())
+ERROR(no_default_arg_macro,none,
+      "default arguments are not allowed in macros", ())
+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,
       "expected a macro identifier for a pound literal expression", ())

include/swift/AST/DiagnosticsSema.def

@@ -6742,12 +6742,33 @@ ERROR(expected_macro_expansion_expr,PointsToFirstBadToken,
 ERROR(macro_undefined,PointsToFirstBadToken,
       "macro %0 is undefined; use `-load-plugin-library` to specify dynamic "
       "libraries that contain this macro", (Identifier))
+ERROR(external_macro_not_found,none,
+      "external implementation struct '%0.%1' could not be found in for "
+      "macro %2; the type must be public and provided via "
+      "'-load-plugin-library'", (StringRef, StringRef, DeclName))
 NOTE(macro_note, none,
-     "macro %0: %1", (Identifier, StringRef))
+     "%1 (in macro %0)", (DeclName, StringRef))
 WARNING(macro_warning, none,
-        "macro %0: %1", (Identifier, StringRef))
+        "%1 (in macro %0)", (DeclName, StringRef))
 ERROR(macro_error, none,
-      "macro %0: %1", (Identifier, StringRef))
+      "%1 (in macro %0)", (DeclName, StringRef))
+ERROR(macro_type_access,none,
+      "macro %select{must be declared "
+      "%select{private|fileprivate|internal|%error|%error}1"
+      "|cannot be declared "
+      "%select{in this context|fileprivate|internal|public|open}1}0 "
+      "because its %select{parameter|result type}3 uses "
+      "%select{a private|a fileprivate|an internal|%error|%error}2 type",
+      (bool, AccessLevel, AccessLevel, bool))
+WARNING(macro_type_access_warn,none,
+        "macro %select{should be declared "
+        "%select{private|fileprivate|internal|%error|%error}1"
+        "|should not be declared %select{in this context|fileprivate|internal|public|open}1}0 "
+        "because its %select{parameter|result type}3 uses "
+        "%select{a private|a fileprivate|an internal|%error|%error}2 type",
+        (bool, AccessLevel, AccessLevel, bool))
+ERROR(macro_in_nested,none,
+      "macro %0 can only be declared at file scope", (DeclName))
 
 //------------------------------------------------------------------------------
 // MARK: Move Only Errors

include/swift/AST/Expr.h

@@ -6021,6 +6021,9 @@ class MacroExpansionExpr final : public Expr {
   ArgumentList *ArgList;
   Expr *Rewritten;
 
+  /// The referenced macro.
+  ConcreteDeclRef macroRef;
+
 public:
   explicit MacroExpansionExpr(SourceLoc poundLoc, DeclNameRef macroName,
                               DeclNameLoc macroNameLoc,
@@ -6053,6 +6056,9 @@ class MacroExpansionExpr final : public Expr {
 
   SourceLoc getLoc() const { return PoundLoc; }
 
+  ConcreteDeclRef getMacroRef() const { return macroRef; }
+  void setMacroRef(ConcreteDeclRef ref) { macroRef = ref; }
+
   SourceRange getSourceRange() const;
 
   static bool classof(const Expr *E) {