Rename @_predatesConcurrency to @preconcurrency.

Introduce the `@preconcurrency` attribute name for `@_predatesConcurrency`,
which has been the favored name in the pitch thread so far. Retain the
old name for now to help smooth migration.

Author: DougGregor

include/swift/AST/ASTMangler.h

@@ -70,7 +70,7 @@ class ASTMangler : public Mangler {
   /// Whether the mangling predates concurrency, and therefore shouldn't
   /// include concurrency features such as global actors or @Sendable
   /// function types.
-  bool PredatesConcurrency = false;
+  bool Preconcurrency = false;
 
 public:
   using SymbolicReferent = llvm::PointerUnion<const NominalTypeDecl *,

include/swift/AST/Attr.def

@@ -688,9 +688,9 @@ SIMPLE_DECL_ATTR(_noAllocation, NoAllocation,
   ABIStableToAdd | ABIStableToRemove | APIStableToAdd | APIStableToRemove,
   124)
 
-SIMPLE_DECL_ATTR(_predatesConcurrency, PredatesConcurrency,
+SIMPLE_DECL_ATTR(preconcurrency, Preconcurrency,
   OnFunc | OnConstructor | OnProtocol | OnGenericType | OnVar | OnSubscript |
-  OnEnumElement | OnImport | UserInaccessible |
+  OnEnumElement | OnImport |
   ABIBreakingToAdd | ABIBreakingToRemove | APIBreakingToAdd | APIBreakingToRemove,
   125)
 

include/swift/AST/Decl.h

@@ -896,7 +896,7 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
   void setHoisted(bool hoisted = true) { Bits.Decl.Hoisted = hoisted; }
 
   /// Whether this declaration predates the introduction of concurrency.
-  bool predatesConcurrency() const;
+  bool preconcurrency() const;
 
 public:
   bool escapedFromIfConfig() const {

include/swift/AST/DiagnosticsParse.def

@@ -1732,7 +1732,7 @@ ERROR(sil_inst_autodiff_invalid_witness_generic_signature,PointsToFirstBadToken,
       (StringRef, StringRef))
 
 WARNING(warn_attr_unsafe_removed,none,
-        "'%0' attribute has been removed in favor of @_predatesConcurrency",
+        "'%0' attribute has been removed in favor of @preconcurrency",
         (StringRef))
 
 //------------------------------------------------------------------------------

include/swift/AST/DiagnosticsSema.def

@@ -1953,11 +1953,11 @@ NOTE(add_nominal_sendable_conformance,none,
      "consider making %0 %1 conform to the 'Sendable' protocol",
      (DescriptiveDeclKind, DeclName))
 REMARK(add_predates_concurrency_import,none,
-     "add '@_predatesConcurrency' to %select{suppress|treat}0 "
+     "add '@preconcurrency' to %select{suppress|treat}0 "
      "'Sendable'-related %select{warnings|errors}0 from module %1"
      "%select{| as warnings}0", (bool, Identifier))
 REMARK(remove_predates_concurrency_import,none,
-     "'@_predatesConcurrency' attribute on module %0 is unused", (Identifier))
+     "'@preconcurrency' attribute on module %0 is unused", (Identifier))
 WARNING(public_decl_needs_sendable,none,
         "public %0 %1 does not specify whether it is 'Sendable' or not",
         (DescriptiveDeclKind, DeclName))

include/swift/AST/Import.h

@@ -82,7 +82,7 @@ enum class ImportFlags {
 
   /// The module is imported assuming that the module itself predates
   /// concurrency.
-  PredatesConcurrency = 0x20,
+  Preconcurrency = 0x20,
 
   /// Used for DenseMap.
   Reserved = 0x80
@@ -550,17 +550,17 @@ struct AttributedImport {
   /// Names of explicitly imported SPI groups.
   ArrayRef<Identifier> spiGroups;
 
-  /// When the import declaration has a `@_predatesConcurrency` annotation, this
+  /// When the import declaration has a `@preconcurrency` annotation, this
   /// is the source range covering the annotation.
-  SourceRange predatesConcurrencyRange;
+  SourceRange preconcurrencyRange;
 
   AttributedImport(ModuleInfo module, SourceLoc importLoc = SourceLoc(),
                    ImportOptions options = ImportOptions(),
                    StringRef filename = {}, ArrayRef<Identifier> spiGroups = {},
-                   SourceRange predatesConcurrencyRange = {})
+                   SourceRange preconcurrencyRange = {})
       : module(module), importLoc(importLoc), options(options),
         sourceFileArg(filename), spiGroups(spiGroups),
-        predatesConcurrencyRange(predatesConcurrencyRange) {
+        preconcurrencyRange(preconcurrencyRange) {
     assert(!(options.contains(ImportFlags::Exported) &&
              options.contains(ImportFlags::ImplementationOnly)) ||
            options.contains(ImportFlags::Reserved));
@@ -570,7 +570,7 @@ struct AttributedImport {
   AttributedImport(ModuleInfo module, AttributedImport<OtherModuleInfo> other)
     : AttributedImport(module, other.importLoc, other.options,
                        other.sourceFileArg, other.spiGroups,
-                       other.predatesConcurrencyRange) { }
+                       other.preconcurrencyRange) { }
 
   friend bool operator==(const AttributedImport<ModuleInfo> &lhs,
                          const AttributedImport<ModuleInfo> &rhs) {

include/swift/AST/SourceFile.h

@@ -84,9 +84,9 @@ class SourceFile final : public FileUnit {
   /// This is \c None until it is filled in by the import resolution phase.
   Optional<ArrayRef<AttributedImport<ImportedModule>>> Imports;
 
-  /// Which imports have made use of @_predatesConcurrency.
+  /// Which imports have made use of @preconcurrency.
   llvm::SmallDenseSet<AttributedImport<ImportedModule>>
-      PredatesConcurrencyImportsUsed;
+      PreconcurrencyImportsUsed;
 
   /// A unique identifier representing this file; used to mark private decls
   /// within the file to keep them from conflicting with other files in the
@@ -297,12 +297,12 @@ class SourceFile final : public FileUnit {
   /// resolution.
   void setImports(ArrayRef<AttributedImport<ImportedModule>> imports);
 
-  /// Whether the given import has used @_predatesConcurrency.
-  bool hasImportUsedPredatesConcurrency(
+  /// Whether the given import has used @preconcurrency.
+  bool hasImportUsedPreconcurrency(
       AttributedImport<ImportedModule> import) const;
 
-  /// Note that the given import has used @_predatesConcurrency/
-  void setImportUsedPredatesConcurrency(
+  /// Note that the given import has used @preconcurrency/
+  void setImportUsedPreconcurrency(
       AttributedImport<ImportedModule> import);
 
   enum ImportQueryKind {

lib/AST/ASTMangler.cpp

@@ -2982,7 +2982,7 @@ CanType ASTMangler::getDeclTypeForMangling(
   // If this declaration predates concurrency, adjust its type to not
   // contain type features that were not available pre-concurrency. This
   // cannot alter the ABI in any way.
-  if (decl->predatesConcurrency()) {
+  if (decl->preconcurrency()) {
     ty = ty->stripConcurrency(/*recurse=*/true, /*dropGlobalActor=*/true);
   }
 

lib/AST/Decl.cpp

@@ -725,8 +725,8 @@ Optional<CustomAttrNominalPair> Decl::getGlobalActorAttr() const {
                            None);
 }
 
-bool Decl::predatesConcurrency() const {
-  if (getAttrs().hasAttribute<PredatesConcurrencyAttr>())
+bool Decl::preconcurrency() const {
+  if (getAttrs().hasAttribute<PreconcurrencyAttr>())
     return true;
 
   // Imported C declarations always predate concurrency.

lib/AST/Module.cpp

@@ -2245,14 +2245,14 @@ SourceFile::setImports(ArrayRef<AttributedImport<ImportedModule>> imports) {
   Imports = getASTContext().AllocateCopy(imports);
 }
 
-bool SourceFile::hasImportUsedPredatesConcurrency(
+bool SourceFile::hasImportUsedPreconcurrency(
     AttributedImport<ImportedModule> import) const {
-  return PredatesConcurrencyImportsUsed.count(import) != 0;
+  return PreconcurrencyImportsUsed.count(import) != 0;
 }
 
-void SourceFile::setImportUsedPredatesConcurrency(
+void SourceFile::setImportUsedPreconcurrency(
     AttributedImport<ImportedModule> import) {
-  PredatesConcurrencyImportsUsed.insert(import);
+  PreconcurrencyImportsUsed.insert(import);
 }
 
 bool HasImplementationOnlyImportsRequest::evaluate(Evaluator &evaluator,