Let generated availability attributes of initializers of subclasses inherit the message and renaming from the initializer of the superclass

Author: cbjeukendrup

lib/AST/Availability.cpp

@@ -14,13 +14,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "swift/AST/Availability.h"
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/Attr.h"
 #include "swift/AST/Decl.h"
-#include "swift/AST/Types.h"
-#include "swift/AST/Availability.h"
 #include "swift/AST/PlatformKind.h"
 #include "swift/AST/TypeWalker.h"
+#include "swift/AST/Types.h"
+#include "llvm/ADT/SmallSet.h"
 #include <map>
 
 using namespace swift;
@@ -95,10 +96,11 @@ static void mergeWithInferredAvailability(const AvailableAttr *Attr,
 
 /// Create an implicit availability attribute for the given platform
 /// and with the inferred availability.
-static AvailableAttr *
-createAvailableAttr(PlatformKind Platform,
-                       const InferredAvailability &Inferred,
-                       ASTContext &Context) {
+static AvailableAttr *createAvailableAttr(PlatformKind Platform,
+                                          const InferredAvailability &Inferred,
+                                          StringRef Message, StringRef Rename,
+                                          ValueDecl *RenameDecl,
+                                          ASTContext &Context) {
 
   llvm::VersionTuple Introduced =
       Inferred.Introduced.getValueOr(llvm::VersionTuple());
@@ -107,21 +109,25 @@ createAvailableAttr(PlatformKind Platform,
   llvm::VersionTuple Obsoleted =
       Inferred.Obsoleted.getValueOr(llvm::VersionTuple());
 
-  return new (Context) AvailableAttr(
-      SourceLoc(), SourceRange(), Platform,
-      /*Message=*/StringRef(),
-      /*Rename=*/StringRef(), /*RenameDecl=*/nullptr,
-        Introduced, /*IntroducedRange=*/SourceRange(),
-        Deprecated, /*DeprecatedRange=*/SourceRange(),
-        Obsoleted, /*ObsoletedRange=*/SourceRange(),
-      Inferred.PlatformAgnostic, /*Implicit=*/true,
-      Inferred.IsSPI);
+  return new (Context)
+      AvailableAttr(SourceLoc(), SourceRange(), Platform,
+                    Message, Rename, RenameDecl,
+                    Introduced, /*IntroducedRange=*/SourceRange(),
+                    Deprecated, /*DeprecatedRange=*/SourceRange(),
+                    Obsoleted, /*ObsoletedRange=*/SourceRange(),
+                    Inferred.PlatformAgnostic, /*Implicit=*/true,
+                    Inferred.IsSPI);
 }
 
 void AvailabilityInference::applyInferredAvailableAttrs(
     Decl *ToDecl, ArrayRef<const Decl *> InferredFromDecls,
     ASTContext &Context) {
 
+  // If all AvailableAttrs have the same message, let the new one
+  // inherit that message. The same for rename.
+  llvm::SmallSet<StringRef, 1> Messages;
+  llvm::SmallSet<std::pair<StringRef, ValueDecl *>, 1> Renames;
+
   // Iterate over the declarations and infer required availability on
   // a per-platform basis.
   std::map<PlatformKind, InferredAvailability> Inferred;
@@ -132,14 +138,30 @@ void AvailabilityInference::applyInferredAvailableAttrs(
         continue;
 
       mergeWithInferredAvailability(AvAttr, Inferred[AvAttr->Platform]);
+
+      if (!AvAttr->Message.empty())
+        Messages.insert(AvAttr->Message);
+
+      if (!AvAttr->Rename.empty())
+        Renames.insert({AvAttr->Rename, AvAttr->RenameDecl});
     }
   }
 
   // Create an availability attribute for each observed platform and add
   // to ToDecl.
   DeclAttributes &Attrs = ToDecl->getAttrs();
   for (auto &Pair : Inferred) {
-    auto *Attr = createAvailableAttr(Pair.first, Pair.second, Context);
+    const StringRef Message =
+        Messages.size() == 1 ? *Messages.begin() : StringRef();
+
+    const auto Rename =
+        Renames.size() == 1
+            ? *Renames.begin()
+            : std::pair<StringRef, ValueDecl *>(StringRef(), nullptr);
+
+    auto *Attr = createAvailableAttr(Pair.first, Pair.second, Message,
+                                     Rename.first, Rename.second, Context);
+
     Attrs.add(Attr);
   }
 }

test/attr/attr_availability.swift

@@ -611,7 +611,12 @@ class DeprecatedInitSub1: DeprecatedInitBase {
 
 class DeprecatedInitSub2: DeprecatedInitBase { }
 
-_ = DeprecatedInitSub2(old: 0) // expected-warning {{'init(old:)' is deprecated}}
+_ = DeprecatedInitBase(old: 0) // expected-warning {{'init(old:)' is deprecated: replaced by 'init(new:)'}} expected-note {{use 'init(new:)' instead}} {{24-27=new}}
+_ = DeprecatedInitBase.init(old: 0) // expected-warning {{'init(old:)' is deprecated: replaced by 'init(new:)'}} expected-note {{use 'init(new:)' instead}} {{29-32=new}}
+let _: DeprecatedInitBase = .init(old: 0) // expected-warning {{'init(old:)' is deprecated: replaced by 'init(new:)'}} expected-note {{use 'init(new:)' instead}} {{35-38=new}}
+_ = DeprecatedInitSub2(old: 0) // expected-warning {{'init(old:)' is deprecated: replaced by 'init(new:)'}} expected-note {{use 'init(new:)' instead}} {{24-27=new}}
+_ = DeprecatedInitSub2.init(old: 0) // expected-warning {{'init(old:)' is deprecated: replaced by 'init(new:)'}} expected-note {{use 'init(new:)' instead}} {{29-32=new}}
+let _: DeprecatedInitSub2 = .init(old: 0) // expected-warning {{'init(old:)' is deprecated: replaced by 'init(new:)'}} expected-note {{use 'init(new:)' instead}} {{35-38=new}}
 
 class Base {
   @available(*, unavailable)