Sema: Custom diagnostic for var decls referencing a restricted type

include/swift/AST/DiagnosticsSema.def

@@ -3831,7 +3831,8 @@ ERROR(decl_from_hidden_module,none,
       "in an extension with public or '@usableFromInline' members|"
       "in an extension with conditional conformances|"
       "in a public or '@usableFromInline' conformance|"
-      "in an '@available' attribute here}1; "
+      "in an '@available' attribute here|"
+      "in a property declaration marked public or in a '@frozen' or '@usableFromInline' context}1; "
       "%select{%2 has been imported as implementation-only|"
       "it is an SPI imported from %2|"
       "it is SPI|"
@@ -3848,7 +3849,8 @@ ERROR(typealias_desugars_to_type_from_hidden_module,none,
       "in an extension with public or '@usableFromInline' members|"
       "in an extension with conditional conformance|"
       "in a public or '@usableFromInline' conformance|"
-      "<<ERROR>>}3 "
+      "<<ERROR>>|"
+      "in a property declaration marked public or in a '@frozen' or '@usableFromInline' context}3 "
       "because %select{%4 has been imported as implementation-only|"
       "it is an SPI imported from %4|"
       "<<ERROR>>|"
@@ -3863,7 +3865,8 @@ ERROR(conformance_from_implementation_only_module,none,
       "as result builder here|"
       "in an extension with public or '@usableFromInline' members|"
       "in an extension with conditional conformances|"
-      "<<ERROR>>|<<ERROR>>}2; "
+      "<<ERROR>>|<<ERROR>>|"
+      "in a property declaration marked public or in a '@frozen' or '@usableFromInline' context}2; "
       "%select{%3 has been imported as implementation-only|"
       "the conformance is declared as SPI in %3|"
       "the conformance is declared as SPI|"

lib/Sema/ResilienceDiagnostics.cpp

@@ -263,6 +263,7 @@ static bool shouldDiagnoseDeclAccess(const ValueDecl *D,
   case ExportabilityReason::General:
   case ExportabilityReason::ResultBuilder:
   case ExportabilityReason::PropertyWrapper:
+  case ExportabilityReason::PublicVarDecl:
     return false;
   }
 }

lib/Sema/TypeCheckAccess.cpp

@@ -2376,7 +2376,8 @@ class DeclAvailabilityChecker : public DeclVisitor<DeclAvailabilityChecker> {
     if (seenVars.count(theVar))
       return;
 
-    checkType(theVar->getValueInterfaceType(), /*typeRepr*/nullptr, theVar);
+    checkType(theVar->getValueInterfaceType(), /*typeRepr*/nullptr, theVar,
+              ExportabilityReason::PublicVarDecl);
 
     for (auto attr : theVar->getAttachedPropertyWrappers()) {
       checkType(attr->getType(), attr->getTypeRepr(), theVar,
@@ -2398,7 +2399,8 @@ class DeclAvailabilityChecker : public DeclVisitor<DeclAvailabilityChecker> {
     });
 
     checkType(TP->hasType() ? TP->getType() : Type(),
-              TP->getTypeRepr(), anyVar ? (Decl *)anyVar : (Decl *)PBD);
+              TP->getTypeRepr(), anyVar ? (Decl *)anyVar : (Decl *)PBD,
+              ExportabilityReason::PublicVarDecl);
 
     // Check the property wrapper types.
     if (anyVar) {

lib/Sema/TypeCheckAvailability.h

@@ -69,7 +69,8 @@ enum class DeclAvailabilityFlag : uint8_t {
 using DeclAvailabilityFlags = OptionSet<DeclAvailabilityFlag>;
 
 // This enum must be kept in sync with
-// diag::decl_from_hidden_module and
+// diag::decl_from_hidden_module,
+// diag::typealias_desugars_to_type_from_hidden_module, and
 // diag::conformance_from_implementation_only_module.
 enum class ExportabilityReason : unsigned {
   General,
@@ -79,6 +80,7 @@ enum class ExportabilityReason : unsigned {
   ExtensionWithConditionalConformances,
   Inheritance,
   AvailableAttribute,
+  PublicVarDecl,
 };
 
 /// A description of the restrictions on what declarations can be referenced

test/Availability/spi-available-context.swift

@@ -18,6 +18,6 @@ public class Bar {
 
 @available(macOS 10.10, iOS 8.0, *)
 public class Baz {
-  public var macos: MacOSSPIProto? // expected-error {{cannot use protocol 'MacOSSPIProto' here; it is SPI}}
+  public var macos: MacOSSPIProto? // expected-error {{cannot use protocol 'MacOSSPIProto' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
   public var ios: iOSSPIProto?
 }

test/Availability/spi-available-swift-module.swift

@@ -21,6 +21,6 @@ import Foo
 
 @available(macOS 10.10, iOS 8.0, *)
 public struct Foo {
-  public var macos: MacOSSPIClass // expected-error {{cannot use class 'MacOSSPIClass' here; it is an SPI imported from 'Foo'}}
+  public var macos: MacOSSPIClass // expected-error {{cannot use class 'MacOSSPIClass' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is an SPI imported from 'Foo'}}
   public var ios: iOSSPIClass
 }

test/ClangImporter/availability_spi_as_unavailable.swift

@@ -9,8 +9,8 @@ import SPIContainer
 @_spi(a) public let a: SPIInterface1 = .init()
 @_spi(a) public let b: SPIInterface2 = .init()
 
-public let c: SPIInterface1 = .init() // expected-error{{cannot use class 'SPIInterface1' here; it is an SPI imported from 'SPIContainer'}}
-public let d: SPIInterface2 = .init() // expected-error{{cannot use class 'SPIInterface2' here; it is an SPI imported from 'SPIContainer'}}
+public let c: SPIInterface1 = .init() // expected-error{{cannot use class 'SPIInterface1' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is an SPI imported from 'SPIContainer'}}
+public let d: SPIInterface2 = .init() // expected-error{{cannot use class 'SPIInterface2' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is an SPI imported from 'SPIContainer'}}
 
 @inlinable
 public func inlinableUsingSPI() {
@@ -21,7 +21,7 @@ public func inlinableUsingSPI() {
 public let e: SPIInterface2 = .init()
 
 @available(iOS, unavailable)
-public let f: SPIInterface2 = .init() // expected-error{{cannot use class 'SPIInterface2' here; it is an SPI imported from 'SPIContainer'}}
+public let f: SPIInterface2 = .init() // expected-error{{cannot use class 'SPIInterface2' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is an SPI imported from 'SPIContainer'}}
 
 @inlinable
 @available(macOS, unavailable)

test/ClangImporter/availability_spi_as_unavailable_bridging_header.swift

@@ -5,8 +5,8 @@
 @_spi(a) public let a: SPIInterface1
 @_spi(a) public let b: SPIInterface2
 
-public let c: SPIInterface1 // expected-error{{cannot use class 'SPIInterface1' here; it is an SPI imported from '__ObjC'}}
-public let d: SPIInterface2 // expected-error{{cannot use class 'SPIInterface2' here; it is an SPI imported from '__ObjC'}}
+public let c: SPIInterface1 // expected-error{{cannot use class 'SPIInterface1' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is an SPI imported from '__ObjC'}}
+public let d: SPIInterface2 // expected-error{{cannot use class 'SPIInterface2' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is an SPI imported from '__ObjC'}}
 
 @inlinable
 public func inlinableUsingSPI() { // expected-warning{{public declarations should have an availability attribute with an introduction version}}

test/ClangImporter/availability_spi_transitive.swift

@@ -5,4 +5,4 @@ import SPIContainerImporter
 
 @_spi(a) public let a: SPIInterface1
 
-public let c: SPIInterface1 // expected-error{{cannot use class 'SPIInterface1' here; it is an SPI imported from 'SPIContainer'}}
+public let c: SPIInterface1 // expected-error{{cannot use class 'SPIInterface1' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is an SPI imported from 'SPIContainer'}}

test/SPI/implementation_only_spi_import_exposability.swift

@@ -34,8 +34,8 @@ public protocol IOIProtocol {}
 
 public struct PublicStruct : IOIProtocol, SPIProtocol { // expected-error {{cannot use protocol 'IOIProtocol' in a public or '@usableFromInline' conformance; 'Lib' has been imported as implementation-only}}
 // expected-error @-1 {{cannot use protocol 'SPIProtocol' in a public or '@usableFromInline' conformance; 'Lib' has been imported as implementation-only}}
-  public var spiStruct = SPIStruct() // expected-error {{cannot use struct 'SPIStruct' here; 'Lib' has been imported as implementation-only}}
-  public var ioiStruct = IOIStruct() // expected-error {{cannot use struct 'IOIStruct' here; 'Lib' has been imported as implementation-only}}
+  public var spiStruct = SPIStruct() // expected-error {{cannot use struct 'SPIStruct' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; 'Lib' has been imported as implementation-only}}
+  public var ioiStruct = IOIStruct() // expected-error {{cannot use struct 'IOIStruct' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; 'Lib' has been imported as implementation-only}}
 
   @inlinable
   public func publicInlinable() {

test/SPI/local_spi_decls.swift

@@ -51,10 +51,10 @@ func inlinable() -> SPIClass { // expected-error {{class 'SPIClass' cannot be us
   // expected-error@-1 {{stored property 'spiInFrozen' cannot be declared '@_spi' in a '@frozen' struct}}
 
   var spiTypeInFrozen = SPIStruct() // expected-error {{struct 'SPIStruct' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
-  // expected-error@-1 {{cannot use struct 'SPIStruct' here; it is SPI}}
+  // expected-error@-1 {{cannot use struct 'SPIStruct' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
   // expected-error@-2 {{initializer 'init()' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
 
-  private var spiTypeInFrozen1: SPIClass // expected-error {{cannot use class 'SPIClass' here; it is SPI}}
+  private var spiTypeInFrozen1: SPIClass // expected-error {{cannot use class 'SPIClass' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 }
 
 @_spi(S)
@@ -81,8 +81,8 @@ public func genFuncBad<T: SPIProtocol>(_ t: T) {} // expected-error {{cannot use
 @_spi(S) func internalCantBeSPI() {} // expected-error{{internal global function cannot be declared '@_spi' because only public and open declarations can be '@_spi'}} {{1-10=}}
 
 public struct PublicStructWithProperties {
-  public var a: SPIClass // expected-error {{cannot use class 'SPIClass' here; it is SPI}}
-  public var b = SPIClass() // expected-error {{cannot use class 'SPIClass' here; it is SPI}}
+  public var a: SPIClass // expected-error {{cannot use class 'SPIClass' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
+  public var b = SPIClass() // expected-error {{cannot use class 'SPIClass' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 }
 
 @_spi(S)

test/SPI/spi-only-import-exportability.swift

@@ -149,7 +149,7 @@ public func implementationDetailsUser() {
 
 public struct ClientStruct {
 #if !SKIP_ERRORS
-  public var a: SPIOnlyStruct // expected-error {{cannot use struct 'SPIOnlyStruct' here; 'SPIOnlyImportedLib' was imported for SPI only}}
+  public var a: SPIOnlyStruct // expected-error {{cannot use struct 'SPIOnlyStruct' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; 'SPIOnlyImportedLib' was imported for SPI only}}
   // expected-error@+1 {{cannot use property 'wrappedValue' here; 'SPIOnlyImportedLib' was imported for SPI only}}
   @SPIOnlyPropertyWrapper(42) public var aWrapped: Any // expected-error {{cannot use generic struct 'SPIOnlyPropertyWrapper' as property wrapper here; 'SPIOnlyImportedLib' was imported for SPI only}}
 #endif

test/SPI/spi_members.swift

@@ -79,7 +79,7 @@ public struct ResilientStructSPIMembers {
   @_spi(Foo) public var computedProperty: SPIType { SPIType() }
 
   @_spi(Foo) public var storedProperty1: SPIType
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
   // expected-error@-2 {{stored property 'storedProperty1' cannot be declared '@_spi' in a '@frozen' struct}}
 
   @_spi(Foo) public var storedProperty2 = SPIType()
@@ -89,7 +89,7 @@ public struct ResilientStructSPIMembers {
   // expected-error@-1 {{stored property 'lazyProperty1' cannot be declared '@_spi' in a '@frozen' struct}}
 
   @_spi(Foo) public lazy var lazyProperty2: SPIType = SPIType()
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
   // expected-error@-2 {{stored property 'lazyProperty2' cannot be declared '@_spi' in a '@frozen' struct}}
 
   @_spi(Foo) @Wrapper public var wrappedProperty1: SPIType
@@ -108,24 +108,24 @@ public struct ResilientStructSPIMembers {
   public func method(_: SPIType) {} // expected-error {{cannot use class 'SPIType' here; it is SPI}}
 
   public var storedProperty1: SPIType
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
   public var storedProperty2 = SPIType()
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
   // expected-error@-2 {{class 'SPIType' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
   // expected-error@-3 {{initializer 'init()' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
 
-  public var computedProperty: SPIType { SPIType() } // expected-error {{cannot use class 'SPIType' here; it is SPI}}
+  public var computedProperty: SPIType { SPIType() } // expected-error {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
-  public lazy var lazyProperty1 = SPIType() // expected-error {{cannot use class 'SPIType' here; it is SPI}}
+  public lazy var lazyProperty1 = SPIType() // expected-error {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
-  public lazy var lazyProperty2: SPIType = SPIType() // expected-error {{cannot use class 'SPIType' here; it is SPI}}
+  public lazy var lazyProperty2: SPIType = SPIType() // expected-error {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
   @Wrapper public var wrappedProperty1: SPIType
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
   @Wrapper public var wrappedProperty2 = SPIType()
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
   // expected-error@-2 {{class 'SPIType' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
   // expected-error@-3 {{initializer 'init()' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
 
@@ -140,24 +140,24 @@ public struct ResilientStructSPIMembers {
   private func method(_: SPIType) {}
 
   private var storedProperty1: SPIType
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
   private var storedProperty2 = SPIType()
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
   // expected-error@-2 {{class 'SPIType' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
   // expected-error@-3 {{initializer 'init()' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
 
   private var computedProperty: SPIType { SPIType() }
 
-  private lazy var lazyProperty1 = SPIType() // expected-error {{cannot use class 'SPIType' here; it is SPI}}
+  private lazy var lazyProperty1 = SPIType() // expected-error {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
-  private lazy var lazyProperty2: SPIType = SPIType() // expected-error {{cannot use class 'SPIType' here; it is SPI}}
+  private lazy var lazyProperty2: SPIType = SPIType() // expected-error {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
   @Wrapper private var wrappedProperty1: SPIType
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
 
   @Wrapper private var wrappedProperty2 = SPIType()
-  // expected-error@-1 {{cannot use class 'SPIType' here; it is SPI}}
+  // expected-error@-1 {{cannot use class 'SPIType' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; it is SPI}}
   // expected-error@-2 {{class 'SPIType' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
   // expected-error@-3 {{initializer 'init()' cannot be used in a property initializer in a '@frozen' type because it is SPI}}
 }

test/Sema/access-level-import-embedded.swift

@@ -171,7 +171,7 @@ public func legalAccessToIndirect(arg: StructFromIndirect = StructFromIndirect()
 
 public struct ExposedLayoutPublic {
   public var publicField: StructFromDirect // expected-error {{property cannot be declared public because its type uses an internal type}}
-  // expected-error @-1 {{cannot use struct 'StructFromDirect' here; 'directs' has been imported as implementation-only}}
+  // expected-error @-1 {{cannot use struct 'StructFromDirect' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; 'directs' has been imported as implementation-only}}
   // expected-note @-2 {{struct 'StructFromDirect' is imported by this file as 'internal' from 'directs'}}
 
   private var privateField: StructFromDirect

test/Sema/implementation-only-import-embedded.swift

@@ -200,7 +200,7 @@ public func legalAccessToIndirect(arg: StructFromIndirect = StructFromIndirect()
 }
 
 public struct ExposedLayoutPublic {
-  public var publicField: StructFromDirect // expected-error {{cannot use struct 'StructFromDirect' here; 'directs' has been imported as implementation-only}}
+  public var publicField: StructFromDirect // expected-error {{cannot use struct 'StructFromDirect' in a property declaration marked public or in a '@frozen' or '@usableFromInline' context; 'directs' has been imported as implementation-only}}
 
   private var privateField: StructFromDirect // FIXME should error
 }