Revert "Extend availability attribute to support feature-based availability"

clang/include/clang/AST/ASTContext.h

@@ -25,7 +25,6 @@
 #include "clang/AST/RawCommentList.h"
 #include "clang/AST/TemplateName.h"
 #include "clang/Basic/LLVM.h"
-#include "clang/Basic/LangOptions.h"
 #include "clang/Basic/PartialDiagnostic.h"
 #include "clang/Basic/SourceLocation.h"
 #include "llvm/ADT/DenseMap.h"
@@ -802,35 +801,6 @@ class ASTContext : public RefCountedBase<ASTContext> {
     return DiagAllocator;
   }
 
-  struct AvailabilityDomainInfo {
-    FeatureAvailKind Kind = FeatureAvailKind::None;
-    ImplicitCastExpr *Call = nullptr;
-    bool isInvalid() const { return Kind == FeatureAvailKind::None; }
-  };
-
-  std::map<StringRef, AvailabilityDomainInfo> AvailabilityDomainMap;
-
-  void addAvailabilityDomainMap(StringRef Name, AvailabilityDomainInfo Info) {
-    AvailabilityDomainMap[Name] = Info;
-  }
-
-  std::pair<DomainAvailabilityAttr *, bool>
-  checkNewFeatureAvailability(Decl *D, StringRef DomainName, bool Unavailable);
-
-  bool hasFeatureAvailabilityAttr(const Decl *D) const;
-
-  // Retrieve availability domain information for a feature.
-  AvailabilityDomainInfo getFeatureAvailInfo(StringRef FeatureName) const;
-
-  // Retrieve feature name and availability domain information on a decl. If the
-  // decl doesn't have attribute availability_domain on it, the name will be
-  // empty and AvailabilityDomainInfo::Kind will be set to
-  // FeatureAvailKind::None.
-  std::pair<StringRef, AvailabilityDomainInfo>
-  getFeatureAvailInfo(Decl *D) const;
-
-  bool hasUnavailableFeature(const Decl *D) const;
-
   const TargetInfo &getTargetInfo() const { return *Target; }
   const TargetInfo *getAuxTargetInfo() const { return AuxTarget; }
 

clang/include/clang/AST/Availability.h

@@ -37,8 +37,6 @@ class AvailabilitySpec {
   /// Name of the platform that Version corresponds to.
   StringRef Platform;
 
-  StringRef DomainName;
-
   SourceLocation BeginLoc, EndLoc;
 
 public:
@@ -47,9 +45,6 @@ class AvailabilitySpec {
       : Version(Version), Platform(Platform), BeginLoc(BeginLoc),
         EndLoc(EndLoc) {}
 
-  AvailabilitySpec(StringRef DomainName, SourceLocation Loc)
-      : DomainName(DomainName), BeginLoc(Loc), EndLoc(Loc) {}
-
   /// This constructor is used when representing the '*' case.
   AvailabilitySpec(SourceLocation StarLoc)
       : BeginLoc(StarLoc), EndLoc(StarLoc) {}
@@ -60,12 +55,7 @@ class AvailabilitySpec {
   SourceLocation getEndLoc() const { return EndLoc; }
 
   /// Returns true when this represents the '*' case.
-  bool isOtherPlatformSpec() const {
-    return Version.empty() && DomainName.empty();
-  }
-
-  bool isDomainName() const { return !DomainName.empty(); }
-  StringRef getDomainName() const { return DomainName; }
+  bool isOtherPlatformSpec() const { return Version.empty(); }
 };
 
 class Decl;

clang/include/clang/AST/ExprObjC.h

@@ -1693,9 +1693,7 @@ class ObjCBridgedCastExpr final
 /// be used in the condition of an \c if, but it is also usable as top level
 /// expressions.
 ///
-class ObjCAvailabilityCheckExpr final
-    : public Expr,
-      private llvm::TrailingObjects<ObjCAvailabilityCheckExpr, char> {
+class ObjCAvailabilityCheckExpr : public Expr {
 public:
   struct VersionAsWritten {
     /// Platform version canonicalized for use with availability checks.
@@ -1706,46 +1704,21 @@ class ObjCAvailabilityCheckExpr final
 
 private:
   friend class ASTStmtReader;
-  friend llvm::TrailingObjects<ObjCAvailabilityCheckExpr, char>;
 
   VersionAsWritten VersionToCheck;
   SourceLocation AtLoc, RParen;
 
-  void setHasDomainName(bool V) {
-    ObjCAvailabilityCheckExprBits.HasDomainName = V;
-  }
-
-  ObjCAvailabilityCheckExpr(SourceLocation AtLoc, SourceLocation RParen,
-                            QualType Ty, StringRef DomainName)
-      : Expr(ObjCAvailabilityCheckExprClass, Ty, VK_PRValue, OK_Ordinary),
-        VersionToCheck(), AtLoc(AtLoc), RParen(RParen) {
-    setDependence(ExprDependence::None);
-    setHasDomainName(true);
-    strcpy(getTrailingObjects<char>(), DomainName.data());
-  }
-
 public:
   ObjCAvailabilityCheckExpr(VersionAsWritten VersionToCheck,
                             SourceLocation AtLoc,
                             SourceLocation RParen, QualType Ty)
       : Expr(ObjCAvailabilityCheckExprClass, Ty, VK_PRValue, OK_Ordinary),
         VersionToCheck(VersionToCheck), AtLoc(AtLoc), RParen(RParen) {
     setDependence(ExprDependence::None);
-    setHasDomainName(false);
   }
 
-  static ObjCAvailabilityCheckExpr *
-  CreateAvailabilityFeatureCheck(SourceLocation AtLoc, SourceLocation RParen,
-                                 QualType Ty, StringRef DomainName,
-                                 const ASTContext &C);
-
   explicit ObjCAvailabilityCheckExpr(EmptyShell Shell)
-      : Expr(ObjCAvailabilityCheckExprClass, Shell) {
-    setHasDomainName(false);
-  }
-
-  static ObjCAvailabilityCheckExpr *
-  CreateEmpty(const ASTContext &C, Stmt::EmptyShell Empty, size_t FeaturesLen);
+      : Expr(ObjCAvailabilityCheckExprClass, Shell) {}
 
   SourceLocation getBeginLoc() const { return AtLoc; }
   SourceLocation getEndLoc() const { return RParen; }
@@ -1758,14 +1731,6 @@ class ObjCAvailabilityCheckExpr final
     return VersionToCheck.SourceVersion;
   }
 
-  bool hasDomainName() const {
-    return ObjCAvailabilityCheckExprBits.HasDomainName;
-  }
-  StringRef getDomainName() const {
-    assert(hasDomainName());
-    return getTrailingObjects<char>();
-  }
-
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }

clang/include/clang/AST/Stmt.h

@@ -1226,15 +1226,6 @@ class alignas(void *) Stmt {
     unsigned ShouldCopy : 1;
   };
 
-  class ObjCAvailabilityCheckExprBitfields {
-    friend class ObjCAvailabilityCheckExpr;
-    LLVM_PREFERRED_TYPE(ExprBitfields)
-    unsigned : NumExprBits;
-
-    LLVM_PREFERRED_TYPE(bool)
-    unsigned HasDomainName : 1;
-  };
-
   //===--- Clang Extensions bitfields classes ---===//
 
   class OpaqueValueExprBitfields {
@@ -1333,7 +1324,6 @@ class alignas(void *) Stmt {
 
     // Obj-C Expressions
     ObjCIndirectCopyRestoreExprBitfields ObjCIndirectCopyRestoreExprBits;
-    ObjCAvailabilityCheckExprBitfields ObjCAvailabilityCheckExprBits;
 
     // Clang Extensions
     OpaqueValueExprBitfields OpaqueValueExprBits;

clang/include/clang/Basic/Attr.td

@@ -1124,25 +1124,6 @@ static llvm::Triple::EnvironmentType getEnvironmentType(llvm::StringRef Environm
   let Documentation = [AvailabilityDocs];
 }
 
-def DomainAvailability : InheritableAttr {
-  // This attribute has no spellings as it is created implicitly when
-  // __attribute__((availability(domain:...))) is seen.
-  let Spellings = [];
-  let Args = [StringArgument<"domain">, BoolArgument<"unavailable">];
-  let AdditionalMembers = [{
-    std::string getFeatureAttributeStr() const;
-  }];
-  let Documentation = [InternalOnly];
-}
-
-// This attribute is used to annotate structs of type `_AvailabilityDomain`.
-def AvailabilityDomain : InheritableAttr {
-  let Spellings = [Clang<"availability_domain">];
-  let Args = [IdentifierArgument<"name">];
-  let Subjects = SubjectList<[Var]>;
-  let Documentation = [Undocumented];
-}
-
 def ExternalSourceSymbol : InheritableAttr {
   let Spellings = [Clang<"external_source_symbol", /*allowInC=*/1,
                    /*version=*/20230206>];

clang/include/clang/Basic/DiagnosticFrontendKinds.td

@@ -144,9 +144,6 @@ def err_fe_invalid_exception_model
 def err_fe_invalid_source_date_epoch : Error<
     "environment variable 'SOURCE_DATE_EPOCH' ('%0') must be a non-negative decimal integer <= %1">;
 
-def err_feature_availability_flag_invalid_value : Error<
-  "invalid value '%0' passed to '-ffeature-availability='; expected <feature>:<on|off>">;
-
 def err_fe_incompatible_option_with_remote_cache : Error<
   "'%0' is incompatible with remote caching backend">;
 def err_fe_unable_to_load_include_tree : Error<

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -1122,11 +1122,6 @@ def err_availability_expected_platform : Error<
 def err_availability_expected_environment : Error<
   "expected an environment name, e.g., 'compute'">;
 
-def err_features_domain_name : Error<
-  "expected a domain name">;
-def err_feature_invalid_availability_check : Error<
-  "cannot pass a domain argument along with other arguments">;
-
 // objc_bridge_related attribute
 def err_objcbridge_related_expected_related_class : Error<
   "expected a related Objective-C class name, e.g., 'NSColor'">;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -3960,28 +3960,6 @@ def err_availability_unexpected_parameter: Error<
 def warn_unguarded_availability :
   Warning<"%0 is only available %select{|in %4 environment }3on %1 %2 or newer">,
   InGroup<UnguardedAvailability>, DefaultIgnore;
-def err_unguarded_feature : Error<
-  "use of %0 requires feature '%1' to be %select{available|unavailable}2">;
-def err_label_in_conditionally_guarded_feature : Error<
-  "labels cannot appear in regions conditionally guarded by features">;
-def err_features_invalid_for_decl : Error<
-  "feature attributes cannot be applied to %0">;
-def err_features_invalid_name : Error<
-  "cannot find definition of feature attribute '%0'">;
-def err_features_invalid__arg : Error<
-  "invalid argument %0: must evaluate to 0 or 1">;
-def err_feature_invalid_for_decl : Error<
-  "feature attribute '%0(%1)' cannot be applied to this decl">;
-def err_feature_merge_incompatible : Error<
-  "cannot merge incompatible feature attribute to this decl">;
-def err_new_feature_redeclaration : Error<
-  "new feature attributes cannot be added to redeclarations">;
-def err_feature_invalid_added : Error<
-  "cannot add feature availability to this decl">;
-def note_feature_incompatible0 : Note<
-  "feature attribute %0">;
-def note_feature_incompatible1 : Note<
-  "is incompatible with %0">;
 def warn_unguarded_availability_unavailable :
   Warning<"%0 is unavailable">,
   InGroup<UnguardedAvailability>, DefaultIgnore;

clang/include/clang/Basic/LangOptions.h

@@ -64,8 +64,6 @@ enum class PointerAuthenticationMode : unsigned {
   SignAndAuth
 };
 
-enum class FeatureAvailKind { None, Available, Unavailable, Dynamic };
-
 /// Bitfields of LangOptions, split out from LangOptions in order to ensure that
 /// this large collection of bitfields is a trivial class type.
 class LangOptionsBase {
@@ -546,8 +544,6 @@ class LangOptions : public LangOptionsBase {
   /// This list is sorted.
   std::vector<std::string> ModuleFeatures;
 
-  std::vector<std::string> FeatureAvailability;
-
   /// Options for parsing comments.
   CommentOptions CommentOpts;
 
@@ -565,16 +561,6 @@ class LangOptions : public LangOptionsBase {
   /// host code generation.
   std::string OMPHostIRFile;
 
-  llvm::StringMap<FeatureAvailKind> FeatureAvailabilityMap;
-
-  void setFeatureAvailability(StringRef Feature, FeatureAvailKind Kind) {
-    FeatureAvailabilityMap[Feature] = Kind;
-  }
-
-  FeatureAvailKind getFeatureAvailability(StringRef Feature) const {
-    return FeatureAvailabilityMap.lookup(Feature);
-  }
-
   /// The user provided compilation unit ID, if non-empty. This is used to
   /// externalize static variables which is needed to support accessing static
   /// device variables in host code for single source offloading languages

clang/include/clang/Driver/Options.td

@@ -3433,10 +3433,6 @@ def fno_builtin : Flag<["-"], "fno-builtin">, Group<f_Group>,
 def fno_builtin_ : Joined<["-"], "fno-builtin-">, Group<f_Group>,
   Visibility<[ClangOption, CC1Option, CLOption, DXCOption]>,
   HelpText<"Disable implicit builtin knowledge of a specific function">;
-def ffeature_availability_EQ : Joined<["-"], "ffeature-availability=">, Group<f_Group>,
-  Visibility<[CC1Option]>,
-  HelpText<"feature availability">,
-  MarshallingInfoStringVector<LangOpts<"FeatureAvailability">>;
 def fno_common : Flag<["-"], "fno-common">, Group<f_Group>,
   Visibility<[ClangOption, CC1Option]>,
     HelpText<"Compile common globals like normal definitions">;

clang/include/clang/Parse/Parser.h

@@ -3127,12 +3127,6 @@ class Parser : public CodeCompletionHandler {
   void ParseHLSLQualifiers(ParsedAttributes &Attrs);
 
   VersionTuple ParseVersionTuple(SourceRange &Range);
-  void ParseFeatureAvailabilityAttribute(
-      IdentifierInfo &Availability, SourceLocation AvailabilityLoc,
-      ParsedAttributes &attrs, SourceLocation *endLoc,
-      IdentifierInfo *ScopeName, SourceLocation ScopeLoc, ParsedAttr::Form Form,
-      BalancedDelimiterTracker &T);
-
   void ParseAvailabilityAttribute(IdentifierInfo &Availability,
                                   SourceLocation AvailabilityLoc,
                                   ParsedAttributes &attrs,

clang/include/clang/Sema/DelayedDiagnostic.h

@@ -125,12 +125,7 @@ class AccessedEntity {
 /// the complete parsing of the current declaration.
 class DelayedDiagnostic {
 public:
-  enum DDKind : unsigned char {
-    Availability,
-    FeatureAvailability,
-    Access,
-    ForbiddenType
-  };
+  enum DDKind : unsigned char { Availability, Access, ForbiddenType };
 
   DDKind Kind;
   bool Triggered;
@@ -148,9 +143,6 @@ class DelayedDiagnostic {
                                             StringRef Msg,
                                             bool ObjCPropertyAccess);
 
-  static DelayedDiagnostic
-  makeFeatureAvailability(NamedDecl *D, ArrayRef<SourceLocation> Locs);
-
   static DelayedDiagnostic makeAccess(SourceLocation Loc,
                                       const AccessedEntity &Entity) {
     DelayedDiagnostic DD;
@@ -209,12 +201,6 @@ class DelayedDiagnostic {
     return AvailabilityData.AR;
   }
 
-  const NamedDecl *getFeatureAvailabilityDecl() const {
-    assert(Kind == FeatureAvailability &&
-           "Not a feature availability diagnostic.");
-    return FeatureAvailabilityData.Decl;
-  }
-
   /// The diagnostic ID to emit.  Used like so:
   ///   Diag(diag.Loc, diag.getForbiddenTypeDiagnostic())
   ///     << diag.getForbiddenTypeOperand()
@@ -260,10 +246,6 @@ class DelayedDiagnostic {
     bool ObjCPropertyAccess;
   };
 
-  struct FAD {
-    const NamedDecl *Decl;
-  };
-
   struct FTD {
     unsigned Diagnostic;
     unsigned Argument;
@@ -272,7 +254,6 @@ class DelayedDiagnostic {
 
   union {
     struct AD AvailabilityData;
-    struct FAD FeatureAvailabilityData;
     struct FTD ForbiddenTypeData;
 
     /// Access control.

clang/include/clang/Sema/ParsedAttr.h

@@ -363,8 +363,6 @@ class ParsedAttr final
     return IsProperty;
   }
 
-  bool isAvailabilityAttribute() const { return IsAvailability; }
-
   bool isInvalid() const { return Invalid; }
   void setInvalid(bool b = true) const { Invalid = b; }
 

clang/include/clang/Sema/ScopeInfo.h

@@ -144,8 +144,6 @@ class FunctionScopeInfo {
   /// unavailable.
   bool HasPotentialAvailabilityViolations : 1;
 
-  bool HasPotentialFeatureAvailabilityViolations : 1;
-
   /// A flag that is set when parsing a method that must call super's
   /// implementation, such as \c -dealloc, \c -finalize, or any method marked
   /// with \c __attribute__((objc_requires_super)).
@@ -396,8 +394,7 @@ class FunctionScopeInfo {
         HasBranchIntoScope(false), HasIndirectGoto(false), HasMustTail(false),
         HasDroppedStmt(false), HasOMPDeclareReductionCombiner(false),
         HasFallthroughStmt(false), UsesFPIntrin(false),
-        HasPotentialAvailabilityViolations(false),
-        HasPotentialFeatureAvailabilityViolations(false), ObjCShouldCallSuper(false),
+        HasPotentialAvailabilityViolations(false), ObjCShouldCallSuper(false),
         ObjCIsDesignatedInit(false), ObjCWarnForNoDesignatedInitChain(false),
         ObjCIsSecondaryInit(false), ObjCWarnForNoInitDelegation(false),
         NeedsCoroutineSuspends(true), FoundImmediateEscalatingExpression(false),