Convert SPIGroupsRequest to use split caching

Author: slavapestov

include/swift/AST/Decl.h

@@ -357,7 +357,7 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
   // for the inline bitfields.
   union { uint64_t OpaqueBits;
 
-  SWIFT_INLINE_BITFIELD_BASE(Decl, bitmax(NumDeclKindBits,8)+1+1+1+1+1+1+1+1+1,
+  SWIFT_INLINE_BITFIELD_BASE(Decl, bitmax(NumDeclKindBits,8)+1+1+1+1+1+1+1+1+1+1,
     Kind : bitmax(NumDeclKindBits,8),
 
     /// Whether this declaration is invalid.
@@ -396,7 +396,11 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
 
     /// True if we're in the common case where the GlobalActorAttributeRequest
     /// request returned a pair of null pointers.
-    NoGlobalActorAttribute : 1
+    NoGlobalActorAttribute : 1,
+
+    /// True if we're in the common case where the SPIGroupsRequest
+    /// request returned an empty array of identifiers.
+    NoSPIGroups : 1
   );
 
   SWIFT_INLINE_BITFIELD_FULL(PatternBindingDecl, Decl, 1+1+2+16,
@@ -840,6 +844,7 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
   friend class RawCommentRequest;
   friend class ExpandMemberAttributeMacros;
   friend class GlobalActorAttributeRequest;
+  friend class SPIGroupsRequest;
 
 private:
   llvm::PointerUnion<DeclContext *, ASTContext *> Context;
@@ -874,6 +879,14 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     Bits.Decl.NoGlobalActorAttribute = true;
   }
 
+  bool hasNoSPIGroups() const {
+    return Bits.Decl.NoSPIGroups;
+  }
+
+  void setHasNoSPIGroups() {
+    Bits.Decl.NoSPIGroups = true;
+  }
+
 protected:
 
   Decl(DeclKind kind, llvm::PointerUnion<DeclContext *, ASTContext *> context)
@@ -888,6 +901,7 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     Bits.Decl.LacksObjCInterfaceOrImplementation = false;
     Bits.Decl.NoMemberAttributeMacros = false;
     Bits.Decl.NoGlobalActorAttribute = false;
+    Bits.Decl.NoSPIGroups = false;
   }
 
   /// Get the Clang node associated with this declaration.

include/swift/AST/TypeCheckRequests.h

@@ -3374,7 +3374,8 @@ class PatternTypeRequest
 class SPIGroupsRequest :
     public SimpleRequest<SPIGroupsRequest,
                          llvm::ArrayRef<Identifier>(const Decl *),
-                         RequestFlags::Cached> {
+                         RequestFlags::SeparatelyCached |
+                         RequestFlags::SplitCached> {
 public:
   using SimpleRequest::SimpleRequest;
 
@@ -3387,6 +3388,8 @@ class SPIGroupsRequest :
 
 public:
   bool isCached() const { return true; }
+  std::optional<llvm::ArrayRef<Identifier>> getCachedResult() const;
+  void cacheResult(llvm::ArrayRef<Identifier> result) const;
 };
 
 

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -409,7 +409,7 @@ SWIFT_REQUEST(TypeChecker, ResolveRawLayoutLikeTypeRequest,
               SeparatelyCached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, SPIGroupsRequest,
               llvm::ArrayRef<Identifier>(Decl *),
-              Cached, NoLocationInfo)
+              SeparatelyCached | SplitCached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, SynthesizeMemberwiseInitRequest,
               ConstructorDecl *(NominalTypeDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, ResolveEffectiveMemberwiseInitRequest,

lib/AST/NameLookupRequests.cpp

@@ -469,6 +469,28 @@ void UnqualifiedLookupRequest::writeDependencySink(
   track.addTopLevelName(desc.Name.getBaseName());
 }
 
+//----------------------------------------------------------------------------//
+// SPIGroupsRequest computation.
+//----------------------------------------------------------------------------//
+
+std::optional<llvm::ArrayRef<Identifier>> SPIGroupsRequest::getCachedResult() const {
+  auto *decl = std::get<0>(getStorage());
+  if (decl->hasNoSPIGroups())
+    return ArrayRef<Identifier>();
+
+  return decl->getASTContext().evaluator.getCachedNonEmptyOutput(*this);
+}
+
+void SPIGroupsRequest::cacheResult(llvm::ArrayRef<Identifier> result) const {
+  auto *decl = std::get<0>(getStorage());
+  if (result.empty()) {
+    const_cast<Decl *>(decl)->setHasNoSPIGroups();
+    return;
+  }
+
+  decl->getASTContext().evaluator.cacheNonEmptyOutput(*this, std::move(result));
+}
+
 // The following clang importer requests have some definitions here to prevent
 // linker errors when building lib syntax parser (which doesn't link with the
 // clang importer).