Generalize the recording of parsed accessors.

As part of this, lift the now-unnecessary restriction against
combining a non-mutable addressor with a setter.  I've also
tweaked some of the diagnostics.

This is in preparation for generalized accessors.

Author: rjmccall

include/swift/AST/DiagnosticsParse.def

@@ -257,13 +257,15 @@ ERROR(getset_nontrivial_pattern,none,
       "getter/setter can only be defined for a single variable", ())
 ERROR(expected_rbrace_in_getset,none,
       "expected '}' at end of variable get/set clause", ())
-ERROR(duplicate_property_accessor,none,
-      "duplicate definition of %0", (StringRef))
+ERROR(duplicate_accessor,none,
+      "%select{variable|subscript}0 already has %1", (unsigned, StringRef))
+ERROR(conflicting_accessor,none,
+      "%select{variable|subscript}0 cannot provide both %1 and %2",
+      (unsigned, StringRef, StringRef))
+ERROR(modify_mutatingness_different_from_setter,none,
+      "mutating-ness of 'modify' accessor cannot differ from setter", ())
 NOTE(previous_accessor,none,
-     "previous definition of %0 is here", (StringRef))
-ERROR(conflicting_property_addressor,none,
-      "%select{variable|subscript}0 already has a "
-      "%select{addressor|mutable addressor}1", (unsigned, unsigned))
+     "%select{|previous definition of }1%0 %select{defined |}1here", (StringRef, bool))
 ERROR(expected_accessor_name,none,
       "expected %select{%error|setter|%error|willSet|didSet}0 parameter name",
       (unsigned))
@@ -278,32 +280,22 @@ ERROR(expected_lbrace_accessor,PointsToFirstBadToken,
 ERROR(expected_accessor_kw,none,
       "expected 'get', 'set', 'willSet', or 'didSet' keyword to "
       "start an accessor definition",())
-ERROR(var_set_without_get,none,
-      "variable with a setter must also have a getter", ())
-ERROR(observingproperty_with_getset,none,
-      "%select{willSet|didSet}0 variable must not also have a "
-      "%select{get|set}1 specifier", (unsigned, unsigned))
-ERROR(observingproperty_with_address,none,
-      "variable with addressor may not have %select{willSet|didSet}0",
-      (unsigned))
-ERROR(observingproperty_in_subscript,none,
-      "%select{willSet|didSet}0 is not allowed in subscripts", (unsigned))
+ERROR(missing_getter,none,
+      "%select{variable|subscript}0 with %1 must also have a getter",
+      (unsigned, StringRef))
+ERROR(missing_reading_accessor,none,
+      "%select{variable|subscript}0 with %1 must also have "
+      "a getter or an addressor",
+      (unsigned, StringRef))
+ERROR(observing_accessor_conflicts_with_accessor,none,
+      "%select{'willSet'|'didSet'}0 cannot be provided together with %1",
+      (unsigned, StringRef))
+ERROR(observing_accessor_in_subscript,none,
+      "%select{'willSet'|'didSet'}0 is not allowed in subscripts", (unsigned))
 ERROR(getset_init,none,
       "variable with getter/setter cannot have an initial value", ())
 ERROR(getset_cannot_be_implied,none,
       "variable with implied type cannot have implied getter/setter", ())
-ERROR(mutableaddressor_without_address,none,
-      "%select{variable|subscript}0 must provide either a getter or "
-      "'address' if it provides 'mutableAddress'", (unsigned))
-ERROR(mutableaddressor_with_setter,none,
-      "%select{variable|subscript}0 cannot provide both 'mutableAddress' "
-      " and a setter", (unsigned))
-ERROR(addressor_with_getter,none,
-      "%select{variable|subscript}0 cannot provide both 'address' and "
-      "a getter", (unsigned))
-ERROR(addressor_with_setter,none,
-      "%select{variable|subscript}0 cannot provide both 'address' and "
-      "a setter; use an ordinary getter instead", (unsigned))
 ERROR(behavior_multiple_vars,none,
       "applying property behavior with parameter to multiple variables is "
       "not supported", ())

include/swift/AST/StorageImpl.h

@@ -274,7 +274,8 @@ class StorageImplInfo {
       return;
 
     case WriteImplKind::Set:
-      assert(readImpl == ReadImplKind::Get);
+      assert(readImpl == ReadImplKind::Get ||
+             readImpl == ReadImplKind::Address);
       assert(readWriteImpl == ReadWriteImplKind::MaterializeToTemporary ||
              readWriteImpl == ReadWriteImplKind::MaterializeForSet);
       return;

include/swift/Parse/Parser.h

@@ -876,33 +876,9 @@ class Parser {
 
   void consumeGetSetBody(AbstractFunctionDecl *AFD, SourceLoc LBLoc);
 
-  struct ParsedAccessors {
-    SourceLoc LBLoc, RBLoc;
-    SmallVector<AccessorDecl*, 16> Accessors;
-
-#define ACCESSOR(ID) AccessorDecl *ID = nullptr;
-#include "swift/AST/AccessorKinds.def"
-
-    void record(Parser &P, AbstractStorageDecl *storage, bool invalid,
-                ParseDeclOptions flags, SourceLoc staticLoc,
-                const DeclAttributes &attrs,
-                TypeLoc elementTy, ParameterList *indices,
-                SmallVectorImpl<Decl *> &decls);
-
-    StorageImplInfo
-    classify(Parser &P, AbstractStorageDecl *storage, bool invalid,
-             ParseDeclOptions flags, SourceLoc staticLoc,
-             const DeclAttributes &attrs,
-             TypeLoc elementTy, ParameterList *indices);
-
-    /// Add an accessor.  If there's an existing accessor of this kind,
-    /// return it.  The new accessor is still remembered but will be
-    /// ignored.
-    AccessorDecl *add(AccessorDecl *accessor);
-  };
-
   void parseAccessorAttributes(DeclAttributes &Attributes);
 
+  struct ParsedAccessors;
   bool parseGetSetImpl(ParseDeclOptions Flags,
                        GenericParamList *GenericParams,
                        ParameterList *Indices,