[CodeCompletion] Add "soft deprected" diagnostics for code completion

'available(..., deprecated: <version>)'. If the version is larger than the
current active version, the declaration is "soft deprecated". Emit a
relevant diagnostics for those items. If the version is equal to or
larger than '100000.0', it means the distant future without specifying
the version.

rdar://76122625

Author: rintaro

include/swift/AST/Attr.h

@@ -2088,6 +2088,10 @@ class DeclAttributes {
   /// a declaration is deprecated on all deployment targets, or null otherwise.
   const AvailableAttr *getDeprecated(const ASTContext &ctx) const;
 
+  /// Returns the first @available attribute that indicates
+  /// a declaration will be deprecated in the future, or null otherwise.
+  const AvailableAttr *getSoftDeprecated(const ASTContext &ctx) const;
+
   SWIFT_DEBUG_DUMPER(dump(const Decl *D = nullptr));
   void print(ASTPrinter &Printer, const PrintOptions &Options,
              const Decl *D = nullptr) const;

include/swift/AST/DiagnosticsIDE.def

@@ -33,6 +33,19 @@ WARNING(ide_redundant_import, none,
 NOTE(ide_redundant_import_indirect, none,
      "module %0 is already imported via another module import", (DeclName))
 
+WARNING(ide_availability_softdeprecated, Deprecation,
+        "%select{getter for |setter for |}0%1 will be deprecated"
+        " in %select{a future version|%select{a future version of %3|%3 %5}4}2"
+        "%select{|: %6}6",
+        (unsigned, DeclName, bool, StringRef, bool, llvm::VersionTuple,
+         StringRef))
+
+WARNING(ide_availability_softdeprecated_rename, Deprecation,
+        "%select{getter for |setter for |}0%1 will be deprecated"
+        " in %select{a future version|%select{a future version of %3|%3 %5}4}2"
+        ": renamed to '%6'",
+        (unsigned, DeclName, bool, StringRef, bool, llvm::VersionTuple, StringRef))
+
 //===----------------------------------------------------------------------===//
 
 #define UNDEFINE_DIAGNOSTIC_MACROS

include/swift/IDE/CodeCompletion.h

@@ -617,6 +617,7 @@ class CodeCompletionResult {
     RedundantImport,
     RedundantImportIndirect,
     Deprecated,
+    SoftDeprecated,
     InvalidAsyncContext,
     CrossActorReference,
     VariableUsedInOwnDefinition,

lib/AST/Attr.cpp

@@ -326,6 +326,38 @@ DeclAttributes::getDeprecated(const ASTContext &ctx) const {
   return conditional;
 }
 
+const AvailableAttr *
+DeclAttributes::getSoftDeprecated(const ASTContext &ctx) const {
+  const AvailableAttr *conditional = nullptr;
+  const AvailableAttr *bestActive = findMostSpecificActivePlatform(ctx);
+  for (auto Attr : *this) {
+    if (auto AvAttr = dyn_cast<AvailableAttr>(Attr)) {
+      if (AvAttr->isInvalid())
+        continue;
+
+      if (AvAttr->hasPlatform() &&
+          (!bestActive || AvAttr != bestActive))
+        continue;
+
+      if (!AvAttr->isActivePlatform(ctx) &&
+          !AvAttr->isLanguageVersionSpecific() &&
+          !AvAttr->isPackageDescriptionVersionSpecific())
+        continue;
+
+      Optional<llvm::VersionTuple> DeprecatedVersion = AvAttr->Deprecated;
+      if (!DeprecatedVersion.hasValue())
+        continue;
+
+      llvm::VersionTuple ActiveVersion = AvAttr->getActiveVersion(ctx);
+
+      if (DeprecatedVersion.getValue() > ActiveVersion) {
+        conditional = AvAttr;
+      }
+    }
+  }
+  return conditional;
+}
+
 void DeclAttributes::dump(const Decl *D) const {
   StreamPrinter P(llvm::errs());
   PrintOptions PO = PrintOptions::printEverything();

lib/IDE/CodeCompletion.cpp

@@ -858,6 +858,8 @@ void CodeCompletionResultBuilder::setAssociatedDecl(const Decl *D) {
 
   if (D->getAttrs().getDeprecated(D->getASTContext()))
     setNotRecommended(NotRecommendedReason::Deprecated);
+  else if (D->getAttrs().getSoftDeprecated(D->getASTContext()))
+    setNotRecommended(NotRecommendedReason::SoftDeprecated);
 }
 
 namespace {

lib/IDE/CodeCompletionDiagnostics.cpp

@@ -42,10 +42,11 @@ CodeCompletionDiagnosticSeverity getSeverity(DiagnosticKind DiagKind) {
 }
 
 class CodeCompletionDiagnostics {
+  ASTContext &Ctx;
   DiagnosticEngine &Engine;
 
 public:
-  CodeCompletionDiagnostics(ASTContext &Ctx) : Engine(Ctx.Diags) {}
+  CodeCompletionDiagnostics(ASTContext &Ctx) : Ctx(Ctx), Engine(Ctx.Diags) {}
 
   template <typename... ArgTypes>
   bool
@@ -75,7 +76,12 @@ bool CodeCompletionDiagnostics::getDiagnostics(
 bool CodeCompletionDiagnostics::getDiagnosticForDeprecated(
     const ValueDecl *D, CodeCompletionDiagnosticSeverity &severity,
     llvm::raw_ostream &Out) {
-  const AvailableAttr *Attr = D->getAttrs().getDeprecated(D->getASTContext());
+  bool isSoftDeprecated = false;
+  const AvailableAttr *Attr = D->getAttrs().getDeprecated(Ctx);
+  if (!Attr) {
+    Attr = D->getAttrs().getSoftDeprecated(Ctx);
+    isSoftDeprecated = true;
+  }
   if (!Attr)
     return true;
 
@@ -91,22 +97,47 @@ bool CodeCompletionDiagnostics::getDiagnosticForDeprecated(
   if (Attr->Deprecated)
     DeprecatedVersion = Attr->Deprecated.getValue();
 
-  if (Attr->Message.empty() && Attr->Rename.empty()) {
-    getDiagnostics(severity, Out, diag::availability_deprecated,
-                   RawAccessorKind, Name, Attr->hasPlatform(), Platform,
-                   Attr->Deprecated.hasValue(), DeprecatedVersion,
-                   /*message*/ StringRef());
-  } else if (!Attr->Message.empty()) {
-    EncodedDiagnosticMessage EncodedMessage(Attr->Message);
-    getDiagnostics(severity, Out, diag::availability_deprecated,
-                   RawAccessorKind, Name, Attr->hasPlatform(), Platform,
-                   Attr->Deprecated.hasValue(), DeprecatedVersion,
-                   EncodedMessage.Message);
+  if (!isSoftDeprecated) {
+    if (Attr->Message.empty() && Attr->Rename.empty()) {
+      getDiagnostics(severity, Out, diag::availability_deprecated,
+                     RawAccessorKind, Name, Attr->hasPlatform(), Platform,
+                     Attr->Deprecated.hasValue(), DeprecatedVersion,
+                     /*message*/ StringRef());
+    } else if (!Attr->Message.empty()) {
+      EncodedDiagnosticMessage EncodedMessage(Attr->Message);
+      getDiagnostics(severity, Out, diag::availability_deprecated,
+                     RawAccessorKind, Name, Attr->hasPlatform(), Platform,
+                     Attr->Deprecated.hasValue(), DeprecatedVersion,
+                     EncodedMessage.Message);
+    } else {
+      getDiagnostics(severity, Out, diag::availability_deprecated_rename,
+                     RawAccessorKind, Name, Attr->hasPlatform(), Platform,
+                     Attr->Deprecated.hasValue(), DeprecatedVersion, false,
+                     /*ReplaceKind*/ 0, Attr->Rename);
+    }
   } else {
-    getDiagnostics(severity, Out, diag::availability_deprecated_rename,
-                   RawAccessorKind, Name, Attr->hasPlatform(), Platform,
-                   Attr->Deprecated.hasValue(), DeprecatedVersion, false,
-                   /*ReplaceKind*/ 0, Attr->Rename);
+    // '100000' is used as a version number in API that will be deprecated in an
+    // upcoming release. This number is to match the 'API_TO_BE_DEPRECATED'
+    // macro defined in Darwin platforms.
+    static llvm::VersionTuple DISTANT_FUTURE_VESION(100000);
+    bool isDistantFuture = DeprecatedVersion >= DISTANT_FUTURE_VESION;
+
+    if (Attr->Message.empty() && Attr->Rename.empty()) {
+      getDiagnostics(severity, Out, diag::ide_availability_softdeprecated,
+                     RawAccessorKind, Name, Attr->hasPlatform(), Platform,
+                     !isDistantFuture, DeprecatedVersion,
+                     /*message*/ StringRef());
+    } else if (!Attr->Message.empty()) {
+      EncodedDiagnosticMessage EncodedMessage(Attr->Message);
+      getDiagnostics(severity, Out, diag::ide_availability_softdeprecated,
+                     RawAccessorKind, Name, Attr->hasPlatform(), Platform,
+                     !isDistantFuture, DeprecatedVersion,
+                     EncodedMessage.Message);
+    } else {
+      getDiagnostics(severity, Out, diag::ide_availability_softdeprecated_rename,
+                     RawAccessorKind, Name, Attr->hasPlatform(), Platform,
+                     !isDistantFuture, DeprecatedVersion, Attr->Rename);
+    }
   }
   return false;;
 }
@@ -123,32 +154,27 @@ bool swift::ide::getCompletionDiagnostics(
   CodeCompletionDiagnostics Diag(ctx);
   switch (reason) {
   case NotRecommendedReason::Deprecated:
+  case NotRecommendedReason::SoftDeprecated:
     return Diag.getDiagnosticForDeprecated(D, severity, Out);
-    break;
   case NotRecommendedReason::InvalidAsyncContext:
     // FIXME: Could we use 'diag::async_in_nonasync_function'?
-    Diag.getDiagnostics(severity, Out, diag::ide_async_in_nonasync_context,
+    return Diag.getDiagnostics(severity, Out, diag::ide_async_in_nonasync_context,
                         D->getName());
-    break;
   case NotRecommendedReason::CrossActorReference:
-    Diag.getDiagnostics(severity, Out, diag::ide_cross_actor_reference_swift5,
+    return Diag.getDiagnostics(severity, Out, diag::ide_cross_actor_reference_swift5,
                         D->getName());
-    break;
   case NotRecommendedReason::RedundantImport:
-    Diag.getDiagnostics(severity, Out, diag::ide_redundant_import,
+    return Diag.getDiagnostics(severity, Out, diag::ide_redundant_import,
                         D->getName());
-    break;
   case NotRecommendedReason::RedundantImportIndirect:
-    Diag.getDiagnostics(severity, Out, diag::ide_redundant_import_indirect,
+    return Diag.getDiagnostics(severity, Out, diag::ide_redundant_import_indirect,
                         D->getName());
-    break;
   case NotRecommendedReason::VariableUsedInOwnDefinition:
-    Diag.getDiagnostics(severity, Out, diag::recursive_accessor_reference,
+    return Diag.getDiagnostics(severity, Out, diag::recursive_accessor_reference,
                         D->getName().getBaseIdentifier(), /*"getter"*/ 0);
-    break;
   case NotRecommendedReason::None:
     llvm_unreachable("invalid not recommended reason");
   }
-  return false;
+  return true;
 }
 

lib/IDE/CodeCompletionDiagnostics.h

@@ -21,6 +21,8 @@ class ValueDecl;
 
 namespace ide {
 
+/// Populate \p severity and \p Out with the diagnostics for \p D.
+/// Returns \c true if it fails to generate the diagnostics.
 bool getCompletionDiagnostics(CodeCompletionResult::NotRecommendedReason reason,
                               const ValueDecl *D,
                               CodeCompletionDiagnosticSeverity &severity,

test/IDE/complete_diagnostics.swift

@@ -48,6 +48,27 @@ public struct Foo {
 
   @available(swift, deprecated: 3.2)
   public var deprecatedVar: Int { 1 }
+
+  @available(macOS, deprecated: 987.6)
+  public func softDeprecatedPlatformVersion() {}
+
+  @available(macOS, deprecated: 765.5, message: "this is a \"message\"")
+  public func softDeprecatedPlatformVersionMessage() {}
+
+  @available(swift, deprecated: 1000.1)
+  public var softDeprecatedVar: Int { 1 }
+
+  @available(macOS, deprecated: 654.3, renamed: "renamedName")
+  public func softDeprecatedPlatformVersionRenamed() {}
+
+  @available(macOS, deprecated: 100000.0)
+  public func futureDeprecatedPlatformVersion() {}
+
+  @available(macOS, deprecated: 100000.0, message: "this is a \"message\"")
+  public func futureDeprecatedPlatformVersionMessage() {}
+
+  @available(macOS, deprecated: 100000.0, renamed: "renamedName")
+  public func futureDeprecatedPlatformVersionRenamed() {}
 }
 
 // BEGIN App.swift
@@ -71,6 +92,13 @@ func test(foo: Foo) {
 // MEMBER-DAG: Decl[InstanceMethod]/CurrNominal/NotRecommended: deprecatedPlatformVersionRenamed()[#Void#]; name=deprecatedPlatformVersionRenamed(); diagnostics=warning:'deprecatedPlatformVersionRenamed()' was deprecated in macOS 10.4: renamed to 'renamedName'{{$}}
 // MEMBER-DAG: Decl[InstanceMethod]/CurrNominal/NotRecommended: deprecatedPlatformVersionMessageRenamed()[#Void#]; name=deprecatedPlatformVersionMessageRenamed(); diagnostics=warning:'deprecatedPlatformVersionMessageRenamed()' was deprecated in macOS 10.4: this is a message{{$}}
 // MEMBER-DAG: Decl[InstanceVar]/CurrNominal/NotRecommended: deprecatedVar[#Int#]; name=deprecatedVar; diagnostics=warning:'deprecatedVar' is deprecated{{$}}
+// MEMBER-DAG: Decl[InstanceMethod]/CurrNominal/NotRecommended: softDeprecatedPlatformVersion()[#Void#]; name=softDeprecatedPlatformVersion(); diagnostics=warning:'softDeprecatedPlatformVersion()' will be deprecated in macOS 987.6{{$}}
+// MEMBER-DAG: Decl[InstanceMethod]/CurrNominal/NotRecommended: softDeprecatedPlatformVersionMessage()[#Void#]; name=softDeprecatedPlatformVersionMessage(); diagnostics=warning:'softDeprecatedPlatformVersionMessage()' will be deprecated in macOS 765.5: this is a "message"{{$}}
+// MEMBER-DAG: Decl[InstanceMethod]/CurrNominal/NotRecommended: softDeprecatedPlatformVersionRenamed()[#Void#]; name=softDeprecatedPlatformVersionRenamed(); diagnostics=warning:'softDeprecatedPlatformVersionRenamed()' will be deprecated in macOS 654.3: renamed to 'renamedName'{{$}}
+// MEMBER-DAG: Decl[InstanceMethod]/CurrNominal/NotRecommended: futureDeprecatedPlatformVersion()[#Void#]; name=futureDeprecatedPlatformVersion(); diagnostics=warning:'futureDeprecatedPlatformVersion()' will be deprecated in a future version of macOS{{$}}
+// MEMBER-DAG: Decl[InstanceMethod]/CurrNominal/NotRecommended: futureDeprecatedPlatformVersionMessage()[#Void#]; name=futureDeprecatedPlatformVersionMessage(); diagnostics=warning:'futureDeprecatedPlatformVersionMessage()' will be deprecated in a future version of macOS: this is a "message"{{$}}
+// MEMBER-DAG: Decl[InstanceMethod]/CurrNominal/NotRecommended: futureDeprecatedPlatformVersionRenamed()[#Void#]; name=futureDeprecatedPlatformVersionRenamed(); diagnostics=warning:'futureDeprecatedPlatformVersionRenamed()' will be deprecated in a future version of macOS: renamed to 'renamedName'{{$}}
+// MEMBER-DAG: Decl[InstanceVar]/CurrNominal/NotRecommended: softDeprecatedVar[#Int#]; name=softDeprecatedVar; diagnostics=warning:'softDeprecatedVar' will be deprecated in a future version{{$}}
 // MEMBER: End completions
 }