Convert AttachedPropertyWrappersRequest to use split caching

Author: slavapestov

include/swift/AST/Decl.h

@@ -452,7 +452,7 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     IsStatic : 1
   );
 
-  SWIFT_INLINE_BITFIELD(VarDecl, AbstractStorageDecl, 2+1+1+1+1+1+1,
+  SWIFT_INLINE_BITFIELD(VarDecl, AbstractStorageDecl, 2+1+1+1+1+1+1+1,
     /// Encodes whether this is a 'let' binding.
     Introducer : 2,
 
@@ -472,6 +472,9 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     /// Whether this is a lazily top-level global variable from the main file.
     IsTopLevelGlobal : 1,
 
+    /// Whether this variable has no attached property wrappers.
+    NoAttachedPropertyWrappers : 1,
+
     /// Whether this variable has no property wrapper auxiliary variables.
     NoPropertyWrapperAuxiliaryVariables : 1
   );
@@ -6158,11 +6161,19 @@ enum class PropertyWrapperSynthesizedPropertyKind {
 /// VarDecl - 'var' and 'let' declarations.
 class VarDecl : public AbstractStorageDecl {
   friend class NamingPatternRequest;
+  friend class AttachedPropertyWrappersRequest;
   friend class PropertyWrapperAuxiliaryVariablesRequest;
 
   NamedPattern *NamingPattern = nullptr;
 
-  /// True if this is a top-level global variable from the main source file.
+  bool hasNoAttachedPropertyWrappers() const {
+    return Bits.VarDecl.NoAttachedPropertyWrappers;
+  }
+
+  void setHasNoAttachedPropertyWrappers() {
+    Bits.VarDecl.NoAttachedPropertyWrappers = true;
+  }
+
   bool hasNoPropertyWrapperAuxiliaryVariables() const {
     return Bits.VarDecl.NoPropertyWrapperAuxiliaryVariables;
   }

include/swift/AST/TypeCheckRequests.h

@@ -800,7 +800,8 @@ class PropertyWrapperTypeInfoRequest
 class AttachedPropertyWrappersRequest :
     public SimpleRequest<AttachedPropertyWrappersRequest,
                          llvm::TinyPtrVector<CustomAttr *>(VarDecl *),
-                         RequestFlags::Cached> {
+                         RequestFlags::SeparatelyCached |
+                         RequestFlags::SplitCached> {
 public:
   using SimpleRequest::SimpleRequest;
 
@@ -812,8 +813,10 @@ class AttachedPropertyWrappersRequest :
   evaluate(Evaluator &evaluator, VarDecl *) const;
 
 public:
-  // Caching
+  // Separate caching.
   bool isCached() const { return true; }
+  std::optional<llvm::TinyPtrVector<CustomAttr *>> getCachedResult() const;
+  void cacheResult(llvm::TinyPtrVector<CustomAttr *> result) const;
 };
 
 /// Request the raw (possibly unbound generic) type of the property wrapper

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -28,7 +28,8 @@ SWIFT_REQUEST(TypeChecker, AttachedResultBuilderRequest,
 SWIFT_REQUEST(TypeChecker, AttachedPropertyWrapperTypeRequest,
               Type(VarDecl *, unsigned), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, AttachedPropertyWrappersRequest,
-              llvm::TinyPtrVector<CustomAttr *>(VarDecl *), Cached,
+              llvm::TinyPtrVector<CustomAttr *>(VarDecl *),
+              SeparatelyCached | SplitCached,
               NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, CallerSideDefaultArgExprRequest,
               Expr *(DefaultArgumentExpr *), SeparatelyCached, NoLocationInfo)

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.NoAttachedPropertyWrappers = false;
   Bits.VarDecl.NoPropertyWrapperAuxiliaryVariables = false;
 }
 

lib/AST/TypeCheckRequests.cpp

@@ -647,6 +647,33 @@ void swift::simple_display(llvm::raw_ostream &out,
   llvm_unreachable("Bad FragileFunctionKind");
 }
 
+//----------------------------------------------------------------------------//
+// AttachedPropertyWrappersRequest computation.
+//----------------------------------------------------------------------------//
+
+std::optional<llvm::TinyPtrVector<CustomAttr *>>
+AttachedPropertyWrappersRequest::getCachedResult() const {
+  auto *decl = std::get<0>(getStorage());
+
+  if (decl->hasNoAttachedPropertyWrappers())
+    return llvm::TinyPtrVector<CustomAttr *>();
+
+  return decl->getASTContext().evaluator.getCachedNonEmptyOutput(*this);
+}
+
+
+void AttachedPropertyWrappersRequest::cacheResult(
+    llvm::TinyPtrVector<CustomAttr *> result) const {
+  auto *decl = std::get<0>(getStorage());
+
+  if (result.empty()) {
+    decl->setHasNoAttachedPropertyWrappers();
+    return;
+  }
+
+  decl->getASTContext().evaluator.cacheNonEmptyOutput(*this, std::move(result));
+}
+
 //----------------------------------------------------------------------------//
 // SelfAccessKindRequest computation.
 //----------------------------------------------------------------------------//