[SPI] Requestify, inherit SPI groups and better diagnostics

include/swift/AST/ASTTypeIDZone.def

@@ -54,3 +54,4 @@ SWIFT_TYPEID_NAMED(TypeAliasDecl *, TypeAliasDecl)
 SWIFT_TYPEID_NAMED(ValueDecl *, ValueDecl)
 SWIFT_TYPEID_NAMED(VarDecl *, VarDecl)
 SWIFT_TYPEID(FingerprintAndMembers)
+SWIFT_TYPEID(Identifier)

include/swift/AST/ASTTypeIDs.h

@@ -62,6 +62,7 @@ struct TypeWitnessAndDecl;
 enum class AncestryFlags : uint8_t;
 enum class ImplicitMemberAction : uint8_t;
 struct FingerprintAndMembers;
+class Identifier;
 
 // Define the AST type zone (zone 1)
 #define SWIFT_TYPEID_ZONE AST

include/swift/AST/AccessScope.h

@@ -24,12 +24,16 @@ namespace swift {
 /// a particular declaration can be accessed.
 class AccessScope {
   /// The declaration context (if not public) along with a bit saying
-  /// whether this scope is private (or not).
+  /// whether this scope is private, SPI or not.
+  /// If the declaration context is set, the bit means that the scope is
+  /// private or not. If the declaration context is null, the bit means that
+  /// this scope is SPI or not.
   llvm::PointerIntPair<const DeclContext *, 1, bool> Value;
+
 public:
-  AccessScope(const DeclContext *DC, bool isPrivate = false);
+  AccessScope(const DeclContext *DC, bool isPrivate = false, bool isSPI = false);
 
-  static AccessScope getPublic() { return AccessScope(nullptr); }
+  static AccessScope getPublic(bool isSPI = false) { return AccessScope(nullptr, false, isSPI); }
 
   /// Check if private access is allowed. This is a lexical scope check in Swift
   /// 3 mode. In Swift 4 mode, declarations and extensions of the same type will
@@ -46,18 +50,24 @@ class AccessScope {
   }
 
   bool isPublic() const { return !Value.getPointer(); }
-  bool isPrivate() const { return Value.getInt(); }
+  bool isPrivate() const { return Value.getPointer() && Value.getInt(); }
   bool isFileScope() const;
   bool isInternal() const;
 
+  // Is this a public scope
+  bool isSPI() const { return !Value.getPointer() && Value.getInt(); }
+
   /// Returns true if this is a child scope of the specified other access scope.
   ///
   /// \see DeclContext::isChildContextOf
   bool isChildOf(AccessScope AS) const {
     if (!isPublic() && !AS.isPublic())
       return allowsPrivateAccess(getDeclContext(), AS.getDeclContext());
-    if (isPublic() && AS.isPublic())
+    if (isPublic() && AS.isPublic()) {
+      if (isSPI() != AS.isSPI())
+        return isSPI();
       return false;
+    }
     return AS.isPublic();
   }
 
@@ -76,6 +86,8 @@ class AccessScope {
   /// have common intersection, or None if scopes don't intersect.
   const Optional<AccessScope> intersectWith(AccessScope accessScope) const {
     if (hasEqualDeclContextWith(accessScope)) {
+      if (isSPI())
+        return *this;
       if (isPrivate())
         return *this;
       return accessScope;

include/swift/AST/Attr.def

@@ -541,8 +541,9 @@ DECL_ATTR(derivative, Derivative,
   97)
 
 DECL_ATTR(_spi, SPIAccessControl,
-  OnFunc | OnExtension | OnGenericType | OnVar | OnSubscript | OnConstructor |
-  OnImport | AllowMultipleAttributes | UserInaccessible |
+  OnAbstractFunction | OnExtension | OnGenericType | OnVar | OnSubscript |
+  OnImport | OnAccessor | OnEnumElement |
+  AllowMultipleAttributes | UserInaccessible |
   ABIStableToAdd | ABIStableToRemove | APIBreakingToAdd | APIStableToRemove,
   98)
 

include/swift/AST/Decl.h

@@ -927,6 +927,16 @@ class alignas(1 << DeclAlignInBits) Decl {
   /// @_originalDefinedIn attribute, this function returns this module name.
   StringRef getAlternateModuleName() const;
 
+  // Is this Decl an SPI? It can be directly marked with @_spi or is defined in
+  // an @_spi context.
+  bool isSPI() const;
+
+  // List the SPI groups declared with @_spi or inherited by this decl.
+  //
+  // SPI groups are inherited from the parent contexts only if the local decl
+  // doesn't declare any @_spi.
+  ArrayRef<Identifier> getSPIGroups() const;
+
   /// Emit a diagnostic tied to this declaration.
   template<typename ...ArgTypes>
   InFlightDiagnostic diagnose(

include/swift/AST/DiagnosticsSema.def

@@ -143,17 +143,17 @@ FIXIT(insert_type_qualification,"%0.",(Type))
 
 ERROR(candidate_inaccessible,none,
       "%0 is inaccessible due to "
-      "'%select{private|fileprivate|internal|SPI|SPI}1' protection level",
+      "'%select{private|fileprivate|internal|@_spi|@_spi}1' protection level",
       (DeclBaseName, AccessLevel))
 
 NOTE(note_candidate_inaccessible,none,
      "%0 is inaccessible due to "
-     "'%select{private|fileprivate|internal|%error|%error}1' protection level",
+     "'%select{private|fileprivate|internal|@_spi|@_spi}1' protection level",
      (DeclName, AccessLevel))
 
 ERROR(init_candidate_inaccessible,none,
       "%0 initializer is inaccessible due to "
-      "'%select{private|fileprivate|internal|SPI|SPI}1' protection level",
+      "'%select{private|fileprivate|internal|@_spi|@_spi}1' protection level",
       (Type, AccessLevel))
 
 ERROR(cannot_pass_rvalue_mutating_subelement,none,
@@ -1649,15 +1649,15 @@ ERROR(function_type_access,none,
       "|cannot be declared "
       "%select{in this context|fileprivate|internal|public|open}1}0 "
       "because its %select{parameter|result}5 uses "
-      "%select{a private|a fileprivate|an internal|%error|%error}3 type",
+      "%select{a private|a fileprivate|an internal|an '@_spi'|an '@_spi'}3 type",
       (bool, AccessLevel, bool, AccessLevel, unsigned, bool))
 ERROR(function_type_spi,none,
       "%select{function|method|initializer}0 "
       "cannot be declared '@_spi' "
       "because its %select{parameter|result}1 uses "
-      "%select{a private|a fileprivate|an internal|%error|%error}2 type "
-      "without a compatible '@_spi'",
-      (unsigned, bool, AccessLevel))
+      "%select{a private|a fileprivate|an internal|a public|an open}2 type"
+      "%select{| that is not '@_spi'}3",
+      (unsigned, bool, AccessLevel, bool))
 WARNING(function_type_access_warn,none,
         "%select{function|method|initializer}4 "
         "%select{should be declared %select{private|fileprivate|internal|%error|%error}1"
@@ -2295,14 +2295,14 @@ ERROR(generic_param_access,none,
       "|cannot be declared "
       "%select{in this context|fileprivate|internal|public|open}2}1 "
       "because its generic %select{parameter|requirement}5 uses "
-      "%select{a private|a fileprivate|an internal|%error|%error}3 type",
+      "%select{a private|a fileprivate|an internal|an '@_spi'|an '@_spi'}3 type",
       (DescriptiveDeclKind, bool, AccessLevel, AccessLevel, bool, bool))
 WARNING(generic_param_access_warn,none,
         "%0 %select{should be declared "
         "%select{private|fileprivate|internal|%error|%error}3"
         "|should not be declared %select{in this context|fileprivate|internal|public|open}2}1 "
         "because its generic %select{parameter|requirement}5 uses "
-        "%select{a private|a fileprivate|an internal|%error|%error}3 type",
+        "%select{a private|a fileprivate|an internal|an '@_spi'|an '@_spi'}3 type",
         (DescriptiveDeclKind, bool, AccessLevel, AccessLevel, bool, bool))
 ERROR(generic_param_usable_from_inline,none,
       "type referenced from a "
@@ -3873,17 +3873,17 @@ ERROR(class_super_access,none,
       "%select{private|fileprivate|internal|%error|%error}1|private or fileprivate}3"
       "|cannot be declared %select{in this context|fileprivate|internal|public|open}1}0 "
       "because its superclass "
-      "%select{is %select{private|fileprivate|internal|%error|%error}2"
-      "|uses %select{a private|a fileprivate|an internal|%error|%error}2 "
+      "%select{is %select{private|fileprivate|internal|'@_spi'|'@_spi'}2"
+      "|uses %select{a private|a fileprivate|an internal|an '@_spi'|an '@_spi'}2 "
       "type as a generic parameter}4",
       (bool, AccessLevel, AccessLevel, bool, bool))
 WARNING(class_super_access_warn,none,
       "class %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 superclass "
-      "%select{is %select{private|fileprivate|internal|%error|%error}2"
-      "|uses %select{a private|a fileprivate|an internal|%error|%error}2 "
+      "%select{is %select{private|fileprivate|internal|'@_spi'|'@_spi'}2"
+      "|uses %select{a private|a fileprivate|an internal|an '@_spi'|an '@_spi'}2 "
       "type as a generic parameter}4",
       (bool, AccessLevel, AccessLevel, bool, bool))
 ERROR(class_super_not_usable_from_inline,none,
@@ -4594,20 +4594,15 @@ ERROR(local_type_in_inlinable_function,
       (DeclName, unsigned))
 
 ERROR(resilience_decl_unavailable,
-      none, DECL_OR_ACCESSOR "4 %1 is %select{private|fileprivate|internal|%error|%error}2 and "
+      none, DECL_OR_ACCESSOR "4 %1 is %select{private|fileprivate|internal|'@_spi'|'@_spi'}2 and "
       "cannot be referenced from " FRAGILE_FUNC_KIND "3",
       (DescriptiveDeclKind, DeclName, AccessLevel, unsigned, bool))
 
 WARNING(resilience_decl_unavailable_warn,
-        none, DECL_OR_ACCESSOR "4 %1 is %select{private|fileprivate|internal|%error|%error}2 and "
+        none, DECL_OR_ACCESSOR "4 %1 is %select{private|fileprivate|internal|'@_spi'|'@_spi'}2 and "
         "should not be referenced from " FRAGILE_FUNC_KIND "3",
         (DescriptiveDeclKind, DeclName, AccessLevel, unsigned, bool))
 
-ERROR(resilience_decl_unavailable_spi,
-      none, DECL_OR_ACCESSOR "4 %1 is imported as SPI; "
-      "it cannot be referenced from " FRAGILE_FUNC_KIND "3",
-      (DescriptiveDeclKind, DeclName, AccessLevel, unsigned, bool))
-
 ERROR(inlinable_decl_ref_from_hidden_module,
       none, "%0 %1 cannot be used in " FRAGILE_FUNC_KIND "2 "
       "because %select{%3 was imported implementation-only|"

include/swift/AST/TypeCheckRequests.h

@@ -2025,6 +2025,26 @@ class PatternTypeRequest
   }
 };
 
+/// List SPI group ids declared on a decl.
+class SPIGroupsRequest :
+    public SimpleRequest<SPIGroupsRequest,
+                         llvm::ArrayRef<Identifier>(const Decl *),
+                         CacheKind::Cached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  llvm::Expected<llvm::ArrayRef<Identifier>>
+  evaluate(Evaluator &evaluator, const Decl *decl) const;
+
+public:
+  bool isCached() const { return true; }
+};
+
+
 /// Type-checks a `@differentiable` attribute and returns the resolved parameter
 /// indices on success. On failure, emits diagnostics and returns `nullptr`.
 ///

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -207,6 +207,9 @@ SWIFT_REQUEST(TypeChecker, PreCheckFunctionBuilderRequest,
 SWIFT_REQUEST(TypeChecker, ResolveImplicitMemberRequest,
               bool(NominalTypeDecl *, ImplicitMemberAction), Uncached,
               NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, SPIGroupsRequest,
+              llvm::ArrayRef<Identifier>(Decl *),
+              Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, SynthesizeMemberwiseInitRequest,
               ConstructorDecl *(NominalTypeDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, HasDefaultInitRequest,

lib/AST/ASTPrinter.cpp

@@ -145,8 +145,11 @@ PrintOptions PrintOptions::printSwiftInterfaceFile(bool preferTypeRepr,
       if (D->getAttrs().hasAttribute<ImplementationOnlyAttr>())
         return false;
 
-      // Skip anything that isn't 'public' or '@usableFromInline',
-      // or SPI if desired.
+      // Skip SPI decls if `PrintSPIs`.
+      if (!options.PrintSPIs && D->isSPI())
+        return false;
+
+      // Skip anything that isn't 'public' or '@usableFromInline'.
       if (auto *VD = dyn_cast<ValueDecl>(D)) {
         if (!isPublicOrUsableFromInline(VD)) {
           // We do want to print private stored properties, without their
@@ -155,11 +158,6 @@ PrintOptions PrintOptions::printSwiftInterfaceFile(bool preferTypeRepr,
             if (contributesToParentTypeStorage(ASD))
               return true;
 
-          // Always print SPI decls if `PrintSPIs`.
-          if (options.PrintSPIs &&
-              VD->getAttrs().hasAttribute<SPIAccessControlAttr>())
-            return true;
-
           return false;
         }
       }
@@ -991,6 +989,17 @@ void PrintAST::printAttributes(const Decl *D) {
       }
     }
 
+    // SPI groups
+    if (Options.PrintSPIs) {
+      interleave(D->getSPIGroups(),
+             [&](Identifier spiName) {
+               Printer.printAttrName("_spi", true);
+               Printer << "(" << spiName << ") ";
+             },
+             [&] { Printer << ""; });
+      Options.ExcludeAttrList.push_back(DAK_SPIAccessControl);
+    }
+
     // Don't print any contextual decl modifiers.
     // We will handle 'mutating' and 'nonmutating' separately.
     if (isa<AccessorDecl>(D)) {