Convert PropertyWrapperAuxiliaryVariablesRequest to use split caching

Author: slavapestov

include/swift/AST/Decl.h

@@ -444,7 +444,7 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     IsStatic : 1
   );
 
-  SWIFT_INLINE_BITFIELD(VarDecl, AbstractStorageDecl, 2+1+1+1+1+1,
+  SWIFT_INLINE_BITFIELD(VarDecl, AbstractStorageDecl, 2+1+1+1+1+1+1,
     /// Encodes whether this is a 'let' binding.
     Introducer : 2,
 
@@ -462,7 +462,10 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     IsPropertyWrapperBackingProperty : 1,
 
     /// Whether this is a lazily top-level global variable from the main file.
-    IsTopLevelGlobal : 1
+    IsTopLevelGlobal : 1,
+
+    /// Whether this variable has no property wrapper auxiliary variables.
+    NoPropertyWrapperAuxiliaryVariables : 1
   );
 
   SWIFT_INLINE_BITFIELD(ParamDecl, VarDecl, 1+2+NumDefaultArgumentKindBits,
@@ -6118,8 +6121,19 @@ enum class PropertyWrapperSynthesizedPropertyKind {
 /// VarDecl - 'var' and 'let' declarations.
 class VarDecl : public AbstractStorageDecl {
   friend class NamingPatternRequest;
+  friend class PropertyWrapperAuxiliaryVariablesRequest;
+
   NamedPattern *NamingPattern = nullptr;
 
+  /// True if this is a top-level global variable from the main source file.
+  bool hasNoPropertyWrapperAuxiliaryVariables() const {
+    return Bits.VarDecl.NoPropertyWrapperAuxiliaryVariables;
+  }
+
+  void setHasNoPropertyWrapperAuxiliaryVariables() {
+    Bits.VarDecl.NoPropertyWrapperAuxiliaryVariables = true;
+  }
+
 public:
   enum class Introducer : uint8_t {
     Let = 0,

include/swift/AST/TypeCheckRequests.h

@@ -902,7 +902,8 @@ class PropertyWrapperLValuenessRequest
 class PropertyWrapperAuxiliaryVariablesRequest :
     public SimpleRequest<PropertyWrapperAuxiliaryVariablesRequest,
                          PropertyWrapperAuxiliaryVariables(VarDecl *),
-                         RequestFlags::Cached> {
+                         RequestFlags::SeparatelyCached |
+                         RequestFlags::SplitCached> {
 public:
   using SimpleRequest::SimpleRequest;
 
@@ -914,8 +915,10 @@ class PropertyWrapperAuxiliaryVariablesRequest :
   evaluate(Evaluator &evaluator, VarDecl *var) const;
 
 public:
-  // Caching
+  // Separate caching.
   bool isCached() const { return true; }
+  std::optional<PropertyWrapperAuxiliaryVariables> getCachedResult() const;
+  void cacheResult(PropertyWrapperAuxiliaryVariables value) const;
 };
 
 /// Request information about initialization of the backing property

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -272,7 +272,8 @@ SWIFT_REQUEST(TypeChecker, PatternBindingCheckedAndContextualizedInitRequest,
 SWIFT_REQUEST(TypeChecker, PrimarySourceFilesRequest,
               ArrayRef<SourceFile *>(ModuleDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, PropertyWrapperAuxiliaryVariablesRequest,
-              PropertyWrapperAuxiliaryVariables(VarDecl *), Cached,
+              PropertyWrapperAuxiliaryVariables(VarDecl *),
+              SeparatelyCached | SplitCached,
               NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, PropertyWrapperInitializerInfoRequest,
               PropertyWrapperInitializerInfo(VarDecl *), Cached,

lib/AST/Decl.cpp

@@ -7409,6 +7409,7 @@ VarDecl::VarDecl(DeclKind kind, bool isStatic, VarDecl::Introducer introducer,
   Bits.VarDecl.IsLazyStorageProperty = false;
   Bits.VarDecl.IsPropertyWrapperBackingProperty = false;
   Bits.VarDecl.IsTopLevelGlobal = false;
+  Bits.VarDecl.NoPropertyWrapperAuxiliaryVariables = false;
 }
 
 Type VarDecl::getTypeInContext() const {

lib/AST/TypeCheckRequests.cpp

@@ -862,6 +862,35 @@ void UnderlyingTypeRequest::diagnoseCycle(DiagnosticEngine &diags) const {
   diags.diagnose(aliasDecl, diag::recursive_decl_reference, aliasDecl);
 }
 
+//----------------------------------------------------------------------------//
+// PropertyWrapperAuxiliaryVariablesRequest computation.
+//----------------------------------------------------------------------------//
+
+std::optional<PropertyWrapperAuxiliaryVariables>
+PropertyWrapperAuxiliaryVariablesRequest::getCachedResult() const {
+  auto storage = getStorage();
+  auto *var = std::get<0>(storage);
+
+  if (var->hasNoPropertyWrapperAuxiliaryVariables())
+    return PropertyWrapperAuxiliaryVariables();
+
+  return var->getASTContext().evaluator.getCachedNonEmptyOutput(*this);
+}
+
+
+void PropertyWrapperAuxiliaryVariablesRequest::cacheResult(
+    PropertyWrapperAuxiliaryVariables value) const {
+  auto storage = getStorage();
+  auto *var = std::get<0>(storage);
+
+  if (!value) {
+    var->setHasNoPropertyWrapperAuxiliaryVariables();
+    return;
+  }
+
+  var->getASTContext().evaluator.cacheNonEmptyOutput(*this, std::move(value));
+}
+
 //----------------------------------------------------------------------------//
 // StructuralTypeRequest computation.
 //----------------------------------------------------------------------------//