AST: Note the attribute that makes a declaration unavailable

include/swift/AST/AvailabilityRestriction.h

@@ -30,6 +30,9 @@ namespace swift {
 class ASTContext;
 class AvailabilityContext;
 class Decl;
+class ExtensionDecl;
+class ValueDecl;
+class RootProtocolConformance;
 
 /// Represents the reason a declaration is considered not available in a
 /// specific `AvailabilityContext`.
@@ -199,6 +202,13 @@ class AvailabilityRestriction {
   /// be translated directly into an `if #available(...)` runtime query.
   bool isActiveForRuntimeQueries(const ASTContext &ctx) const;
 
+  /// Emit a note indicating the source of availability restriction.
+  bool emitNoteForDecl(const ValueDecl *decl) const;
+
+  /// Emit a note indicating the source of availability restriction.
+  bool emitNoteForConformance(const ExtensionDecl *ext,
+                              const RootProtocolConformance *rootConf) const;
+
   void print(raw_ostream &os) const;
 };
 

lib/AST/AvailabilityRestriction.cpp

@@ -14,6 +14,8 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/AvailabilityContext.h"
 #include "swift/AST/Decl.h"
+#include "swift/AST/DiagnosticsSema.h"
+#include "swift/AST/ProtocolConformance.h"
 
 using namespace swift;
 
@@ -63,6 +65,84 @@ bool AvailabilityRestriction::isActiveForRuntimeQueries(
                                  /*forRuntimeQuery=*/true);
 }
 
+bool AvailabilityRestriction::emitNoteForDecl(const ValueDecl *decl) const {
+  auto &ctx = decl->getASTContext();
+  auto &diags = ctx.Diags;
+  auto parsedAttr = getAttr().getParsedAttr();
+  auto sourceRange = parsedAttr->getRangeWithAt();
+  auto domainAndRange = getDomainAndRange(ctx);
+
+  // Point at the attribute so that the reason for the restriction is always
+  // rendered. Implicit attributes, like the ones on imported or synthesized
+  // declarations, have no location; refer to the declaration instead.
+  auto loc = parsedAttr->AtLoc;
+  auto diagnose = [&](const Diagnostic &diag) {
+    return loc.isValid() ? diags.diagnose(loc, diag)
+                         : diags.diagnose(decl, diag);
+  };
+
+  switch (getReason()) {
+  case Reason::UnavailableUnconditionally:
+    diagnose({diag::availability_marked_unavailable, decl})
+        .highlight(sourceRange);
+    break;
+  case Reason::UnavailableUnintroduced:
+    diagnose({diag::availability_introduced_in_version, decl,
+              domainAndRange.getDomain(), domainAndRange.getRange()})
+        .highlight(sourceRange);
+    break;
+  case Reason::UnavailableObsolete:
+    diagnose({diag::availability_obsoleted, decl, domainAndRange.getDomain(),
+              domainAndRange.getRange()})
+        .highlight(sourceRange);
+    break;
+  case Reason::Unintroduced:
+  case Reason::Deprecated:
+    return false;
+  }
+  return true;
+}
+
+bool AvailabilityRestriction::emitNoteForConformance(
+    const ExtensionDecl *ext, const RootProtocolConformance *rootConf) const {
+  auto &ctx = ext->getASTContext();
+  auto &diags = ctx.Diags;
+  auto parsedAttr = getAttr().getParsedAttr();
+  auto sourceRange = parsedAttr->getRangeWithAt();
+  auto type = rootConf->getType();
+  auto proto = rootConf->getProtocol()->getDeclaredInterfaceType();
+  auto domainAndRange = getDomainAndRange(ctx);
+
+  // Point at the attribute so that the reason for the restriction is always
+  // rendered. Implicit attributes, like the ones on imported or synthesized
+  // extensions, have no location; refer to the extension instead.
+  auto loc = parsedAttr->AtLoc;
+  auto diagnose = [&](const Diagnostic &diag) {
+    return loc.isValid() ? diags.diagnose(loc, diag)
+                         : diags.diagnose(ext, diag);
+  };
+
+  switch (getReason()) {
+  case Reason::UnavailableUnconditionally:
+    diagnose({diag::conformance_availability_marked_unavailable, type, proto})
+        .highlight(sourceRange);
+    break;
+  case Reason::UnavailableUnintroduced:
+    diagnose({diag::conformance_availability_introduced_in_version, type, proto,
+              domainAndRange.getDomain(), domainAndRange.getRange()});
+    break;
+  case Reason::UnavailableObsolete:
+    diagnose({diag::conformance_availability_obsoleted, type, proto,
+              domainAndRange.getDomain(), domainAndRange.getRange()})
+        .highlight(sourceRange);
+    break;
+  case Reason::Unintroduced:
+  case Reason::Deprecated:
+    return false;
+  }
+  return true;
+}
+
 void AvailabilityRestriction::print(llvm::raw_ostream &os) const {
   os << "AvailabilityRestriction(";
   getAttr().getDomain().print(os);

lib/Sema/TypeCheckAttr.cpp

@@ -5848,6 +5848,7 @@ void AttributeChecker::checkBackDeployedAttrs(
       // Find the attribute that makes the declaration unavailable.
       const Decl *attrDecl = D;
       do {
+        // FIXME: Adopt AvailabilityRestriction::emitNoteForDecl()
         if (auto unavailableAttr = attrDecl->getUnavailableAttr()) {
           diagnose(unavailableAttr->getParsedAttr()->AtLoc,
                    diag::availability_marked_unavailable, VD)

lib/Sema/TypeCheckAvailability.cpp

@@ -1918,28 +1918,7 @@ bool diagnoseExplicitUnavailability(SourceLoc loc,
       .warnUntilLanguageModeIf(warnIfConformanceUnavailablePreSwift6,
                                LanguageMode::v6);
 
-  switch (restriction.getReason()) {
-  case AvailabilityRestriction::Reason::UnavailableUnconditionally:
-    diags
-        .diagnose(ext, diag::conformance_availability_marked_unavailable, type,
-                  proto)
-        .highlight(attr.getParsedAttr()->getRangeWithAt());
-    break;
-  case AvailabilityRestriction::Reason::UnavailableUnintroduced:
-    diags.diagnose(ext, diag::conformance_availability_introduced_in_version,
-                   type, proto, domainAndRange.getDomain(),
-                   domainAndRange.getRange());
-    break;
-  case AvailabilityRestriction::Reason::UnavailableObsolete:
-    diags
-        .diagnose(ext, diag::conformance_availability_obsoleted, type, proto,
-                  domainAndRange.getDomain(), domainAndRange.getRange())
-        .highlight(attr.getParsedAttr()->getRangeWithAt());
-    break;
-  case AvailabilityRestriction::Reason::Unintroduced:
-  case AvailabilityRestriction::Reason::Deprecated:
-    llvm_unreachable("unexpected restriction");
-  }
+  restriction.emitNoteForConformance(ext, rootConf);
   return true;
 }
 
@@ -2279,29 +2258,7 @@ bool diagnoseExplicitUnavailability(
         .limitBehavior(limit);
   }
 
-  auto sourceRange = Attr.getParsedAttr()->getRangeWithAt();
-  switch (restriction.getReason()) {
-  case AvailabilityRestriction::Reason::UnavailableUnconditionally:
-    diags.diagnose(D, diag::availability_marked_unavailable, D)
-        .highlight(sourceRange);
-    break;
-  case AvailabilityRestriction::Reason::UnavailableUnintroduced:
-    diags
-        .diagnose(D, diag::availability_introduced_in_version, D,
-                  domainAndRange.getDomain(), domainAndRange.getRange())
-        .highlight(sourceRange);
-    break;
-  case AvailabilityRestriction::Reason::UnavailableObsolete:
-    diags
-        .diagnose(D, diag::availability_obsoleted, D,
-                  domainAndRange.getDomain(), domainAndRange.getRange())
-        .highlight(sourceRange);
-    break;
-  case AvailabilityRestriction::Reason::Unintroduced:
-  case AvailabilityRestriction::Reason::Deprecated:
-    llvm_unreachable("unexpected restriction");
-    break;
-  }
+  restriction.emitNoteForDecl(D);
   return true;
 }
 

test/ASTGen/availability.swift

@@ -73,14 +73,14 @@ public class ClassWithMembers {
   public func spiFunc() {}
 }
 
-@available(*, unavailable, renamed: "`class`")
-func keyword_renamed() {} // expected-note {{'keyword_renamed()' has been explicitly marked unavailable here}}
+@available(*, unavailable, renamed: "`class`") // expected-note {{'keyword_renamed()' has been explicitly marked unavailable here}}
+func keyword_renamed() {}
 
-@available(*, unavailable, renamed: "`foo bar`")
-func spaces_renamed() {} // expected-note {{'spaces_renamed()' has been explicitly marked unavailable here}}
+@available(*, unavailable, renamed: "`foo bar`") // expected-note {{'spaces_renamed()' has been explicitly marked unavailable here}}
+func spaces_renamed() {}
 
-@available(*, unavailable, renamed: "foo(`3bar baz`:)")
-func keywords_in_arguments(x: Int) {} // expected-note {{'keywords_in_arguments(x:)' has been explicitly marked unavailable here}}
+@available(*, unavailable, renamed: "foo(`3bar baz`:)") // expected-note {{'keywords_in_arguments(x:)' has been explicitly marked unavailable here}}
+func keywords_in_arguments(x: Int) {}
 
 func testEscapedRenamed() {
   keyword_renamed() // expected-error {{'keyword_renamed()' has been renamed to '`class`'}}

test/ASTGen/embedded_availability.swift

@@ -6,19 +6,19 @@
 
 @_unavailableInEmbedded
 public struct UnavailableInEmbedded {}
-// expected-note@-1 {{'UnavailableInEmbedded' has been explicitly marked unavailable here}}
+// expected-note@-2 {{'UnavailableInEmbedded' has been explicitly marked unavailable here}}
 
 @available(*, unavailable, message: "always unavailable")
 public struct UniverallyUnavailable {}
-// expected-note@-1 3 {{'UniverallyUnavailable' has been explicitly marked unavailable here}}
+// expected-note@-2 3 {{'UniverallyUnavailable' has been explicitly marked unavailable here}}
 
 @_unavailableInEmbedded
 public func unavailable_in_embedded() { }
-// expected-note@-1 {{'unavailable_in_embedded()' has been explicitly marked unavailable here}}
+// expected-note@-2 {{'unavailable_in_embedded()' has been explicitly marked unavailable here}}
 
 @available(*, unavailable, message: "always unavailable")
 public func universally_unavailable() { }
-// expected-note@-1 4 {{'universally_unavailable()' has been explicitly marked unavailable here}}
+// expected-note@-2 4 {{'universally_unavailable()' has been explicitly marked unavailable here}}
 
 @_unavailableInEmbedded
 public func unused() { } // no error
@@ -38,9 +38,9 @@ public func has_universally_unavailable_overload(_ s2: S2) { }
 
 public struct Available {}
 
-@_unavailableInEmbedded
+@_unavailableInEmbedded // expected-note {{'unavailable_in_embedded_method' has been explicitly marked unavailable here}}
 extension Available {
-  public func unavailable_in_embedded_method( // expected-note {{'unavailable_in_embedded_method' has been explicitly marked unavailable here}}
+  public func unavailable_in_embedded_method(
     _ uie: UnavailableInEmbedded,
     _ uu: UniverallyUnavailable, // expected-error {{'UniverallyUnavailable' is unavailable: always unavailable}}
     _ a: Available,

test/Availability/availability.swift

@@ -1,7 +1,7 @@
 // RUN: %target-typecheck-verify-swift -parse-as-library -module-name MyModule
 
-@available(*, unavailable)
-func unavailable_foo() {} // expected-note {{'unavailable_foo()' has been explicitly marked unavailable here}}
+@available(*, unavailable) // expected-note {{'unavailable_foo()' has been explicitly marked unavailable here}}
+func unavailable_foo() {}
 
 @_unavailableInEmbedded // no-op without -enable-experimental-feature Embedded
 public func unavailable_in_embedded() { }
@@ -11,12 +11,12 @@ func test() {
   unavailable_in_embedded() // ok
 }
 
-@available(*,unavailable,message: "use 'Int' instead")
-struct NSUInteger {} // expected-note 3 {{explicitly marked unavailable here}}
+@available(*,unavailable,message: "use 'Int' instead") // expected-note 3 {{explicitly marked unavailable here}}
+struct NSUInteger {}
 
 struct Outer {
-  @available(*,unavailable,message: "use 'UInt' instead")
-  struct NSUInteger {} // expected-note 2 {{explicitly marked unavailable here}}
+  @available(*,unavailable,message: "use 'UInt' instead") // expected-note 2 {{explicitly marked unavailable here}}
+  struct NSUInteger {}
 }
 
 func foo(x : NSUInteger) { // expected-error {{'NSUInteger' is unavailable: use 'Int' instead}}
@@ -34,14 +34,14 @@ func foo(x : NSUInteger) { // expected-error {{'NSUInteger' is unavailable: use
 }
 
 struct VarToFunc {
-  @available(*, unavailable, renamed: "function()")
-  var variable: Int { // expected-note 2 {{explicitly marked unavailable here}}
+  @available(*, unavailable, renamed: "function()") // expected-note 2 {{explicitly marked unavailable here}}
+  var variable: Int {
     get { 0 }
     set {}
   }
 
-  @available(*, unavailable, renamed: "function()")
-  func oldFunction() -> Int { return 42 } // expected-note 2 {{explicitly marked unavailable here}}
+  @available(*, unavailable, renamed: "function()") // expected-note 2 {{explicitly marked unavailable here}}
+  func oldFunction() -> Int { return 42 }
 
   func function() -> Int {
     _ = variable // expected-error{{'variable' has been renamed to 'function()'}}{{9-17=function()}}
@@ -75,8 +75,8 @@ struct DeferBody {
   }
 
   func bar() {
-    @available(*, unavailable)
-    enum No: Error { // expected-note 2 {{'No' has been explicitly marked unavailable here}}
+    @available(*, unavailable) // expected-note 2 {{'No' has been explicitly marked unavailable here}}
+    enum No: Error {
       case no
     }
     do {
@@ -122,8 +122,8 @@ func test_contextual_member_with_availability() {
   _ = Test(.foo) // Ok
 }
 
-@available(*, unavailable)
-func unavailableFunction(_ x: Int) -> Bool { true } // expected-note {{'unavailableFunction' has been explicitly marked unavailable here}}
+@available(*, unavailable) // expected-note {{'unavailableFunction' has been explicitly marked unavailable here}}
+func unavailableFunction(_ x: Int) -> Bool { true }
 
 /// https://github.com/apple/swift/issues/55700
 /// Availability checking not working in the `where` clause of a `for` loop

test/Availability/availability_accessors.swift

@@ -55,22 +55,22 @@ struct BaseStruct<T> {
   }
 
   var unavailableGetter: T {
-    @available(*, unavailable)
-    get { fatalError() } // expected-note 73 {{getter for 'unavailableGetter' has been explicitly marked unavailable here}}
+    @available(*, unavailable) // expected-note 73 {{getter for 'unavailableGetter' has been explicitly marked unavailable here}}
+    get { fatalError() }
     set { }
   }
 
   var unavailableSetter: T {
     get { fatalError() }
-    @available(*, unavailable)
-    set { fatalError() } // expected-note 34 {{setter for 'unavailableSetter' has been explicitly marked unavailable here}}
+    @available(*, unavailable) // expected-note 34 {{setter for 'unavailableSetter' has been explicitly marked unavailable here}}
+    set { fatalError() }
   }
 
   var unavailableGetterAndSetter: T {
-    @available(*, unavailable)
-    get { fatalError() } // expected-note 71 {{getter for 'unavailableGetterAndSetter' has been explicitly marked unavailable here}}
-    @available(*, unavailable)
-    set { fatalError() } // expected-note 34 {{setter for 'unavailableGetterAndSetter' has been explicitly marked unavailable here}}
+    @available(*, unavailable) // expected-note 71 {{getter for 'unavailableGetterAndSetter' has been explicitly marked unavailable here}}
+    get { fatalError() }
+    @available(*, unavailable) // expected-note 34 {{setter for 'unavailableGetterAndSetter' has been explicitly marked unavailable here}}
+    set { fatalError() }
   }
 
   var deprecatedGetter: T {
@@ -93,22 +93,22 @@ struct SubscriptHelper {
   }
 
   subscript<T>(unavailableGetter t: T) -> () {
-    @available(*, unavailable)
-    get { } // expected-note {{getter for 'subscript(unavailableGetter:)' has been explicitly marked unavailable here}}
+    @available(*, unavailable) // expected-note {{getter for 'subscript(unavailableGetter:)' has been explicitly marked unavailable here}}
+    get { }
     set { }
   }
 
   subscript<T>(unavailableSetter t: T) -> () {
     get { }
-    @available(*, unavailable)
-    set { } // expected-note {{setter for 'subscript(unavailableSetter:)' has been explicitly marked unavailable here}}
+    @available(*, unavailable) // expected-note {{setter for 'subscript(unavailableSetter:)' has been explicitly marked unavailable here}}
+    set { }
   }
 
   subscript<T>(unavailableGetterAndSetter t: T) -> () {
-    @available(*, unavailable)
-    get { } // expected-note {{getter for 'subscript(unavailableGetterAndSetter:)' has been explicitly marked unavailable here}}
-    @available(*, unavailable)
-    set { } // expected-note {{setter for 'subscript(unavailableGetterAndSetter:)' has been explicitly marked unavailable here}}
+    @available(*, unavailable) // expected-note {{getter for 'subscript(unavailableGetterAndSetter:)' has been explicitly marked unavailable here}}
+    get { }
+    @available(*, unavailable) // expected-note {{setter for 'subscript(unavailableGetterAndSetter:)' has been explicitly marked unavailable here}}
+    set { }
   }
 }