RequirementMachine: Refactor requests to not be downstream of the GenericSignatureBuilder

This will make it easier to remove the GenericSignatureBuilder (which
still won't happen for a little while).

Author: slavapestov

include/swift/AST/Decl.h

@@ -4389,6 +4389,7 @@ class ProtocolDecl final : public NominalTypeDecl {
   friend class ProtocolDependenciesRequest;
   friend class RequirementSignatureRequest;
   friend class RequirementSignatureRequestRQM;
+  friend class RequirementSignatureRequestGSB;
   friend class ProtocolRequiresClassRequest;
   friend class ExistentialConformsToSelfRequest;
   friend class ExistentialRequiresAnyRequest;

include/swift/AST/TypeCheckRequests.h

@@ -493,6 +493,27 @@ class RequirementSignatureRequestRQM :
   bool isCached() const { return true; }
 };
 
+/// Compute a protocol's requirement signature using the GenericSignatureBuilder.
+/// This is temporary; once the GenericSignatureBuilder goes away this will
+/// be removed.
+class RequirementSignatureRequestGSB :
+    public SimpleRequest<RequirementSignatureRequestGSB,
+                         RequirementSignature(ProtocolDecl *),
+                         RequestFlags::Cached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  RequirementSignature
+  evaluate(Evaluator &evaluator, ProtocolDecl *proto) const;
+
+public:
+  bool isCached() const { return true; }
+};
+
 /// Compute the requirements that describe a protocol.
 class RequirementSignatureRequest :
     public SimpleRequest<RequirementSignatureRequest,
@@ -1793,6 +1814,37 @@ class AbstractGenericSignatureRequestRQM :
   }
 };
 
+/// Build a generic signature using the GenericSignatureBuilder. This is temporary;
+/// once the GenericSignatureBuilder goes away this will be removed.
+class AbstractGenericSignatureRequestGSB :
+    public SimpleRequest<AbstractGenericSignatureRequestGSB,
+                         GenericSignatureWithError (const GenericSignatureImpl *,
+                                                    SmallVector<GenericTypeParamType *, 2>,
+                                                    SmallVector<Requirement, 2>),
+                         RequestFlags::Cached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  GenericSignatureWithError
+  evaluate(Evaluator &evaluator,
+           const GenericSignatureImpl *baseSignature,
+           SmallVector<GenericTypeParamType *, 2> addedParameters,
+           SmallVector<Requirement, 2> addedRequirements) const;
+
+public:
+  // Separate caching.
+  bool isCached() const { return true; }
+
+  /// Abstract generic signature requests never have source-location info.
+  SourceLoc getNearestLoc() const {
+    return SourceLoc();
+  }
+};
+
 class InferredGenericSignatureRequest :
     public SimpleRequest<InferredGenericSignatureRequest,
                          GenericSignatureWithError (ModuleDecl *,
@@ -1876,6 +1928,48 @@ class InferredGenericSignatureRequestRQM :
   void noteCycleStep(DiagnosticEngine &diags) const;
 };
 
+/// Build a generic signature using the GenericSignatureBuilder. This is temporary;
+/// once the GenericSignatureBuilder goes away this will be removed.
+class InferredGenericSignatureRequestGSB :
+    public SimpleRequest<InferredGenericSignatureRequestGSB,
+                         GenericSignatureWithError (ModuleDecl *,
+                                                    const GenericSignatureImpl *,
+                                                    GenericParamList *,
+                                                    WhereClauseOwner,
+                                                    SmallVector<Requirement, 2>,
+                                                    SmallVector<TypeLoc, 2>,
+                                                    bool),
+                         RequestFlags::Cached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  GenericSignatureWithError
+  evaluate(Evaluator &evaluator,
+           ModuleDecl *parentModule,
+           const GenericSignatureImpl *baseSignature,
+           GenericParamList *genericParams,
+           WhereClauseOwner whereClause,
+           SmallVector<Requirement, 2> addedRequirements,
+           SmallVector<TypeLoc, 2> inferenceSources,
+           bool allowConcreteGenericParams) const;
+
+public:
+  // Separate caching.
+  bool isCached() const { return true; }
+
+  /// Inferred generic signature requests don't have source-location info.
+  SourceLoc getNearestLoc() const {
+    return SourceLoc();
+  }
+
+  // Cycle handling.
+  void noteCycleStep(DiagnosticEngine &diags) const;
+};
+
 void simple_display(llvm::raw_ostream &out, const TypeLoc source);
 
 class ExtendedTypeRequest

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -25,6 +25,11 @@ SWIFT_REQUEST(TypeChecker, AbstractGenericSignatureRequestRQM,
                                          SmallVector<GenericTypeParamType *, 2>,
                                          SmallVector<Requirement, 2>),
               Cached, NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, AbstractGenericSignatureRequestGSB,
+              GenericSignatureWithError (const GenericSignatureImpl *,
+                                         SmallVector<GenericTypeParamType *, 2>,
+                                         SmallVector<Requirement, 2>),
+              Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, ApplyAccessNoteRequest,
               evaluator::SideEffect(ValueDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, AttachedResultBuilderRequest,
@@ -192,6 +197,14 @@ SWIFT_REQUEST(TypeChecker, InferredGenericSignatureRequestRQM,
                                          SmallVector<Requirement, 2>,
                                          SmallVector<TypeLoc, 2>, bool),
               Cached, NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, InferredGenericSignatureRequestGSB,
+              GenericSignatureWithError (ModuleDecl *,
+                                         const GenericSignatureImpl *,
+                                         GenericParamList *,
+                                         WhereClauseOwner,
+                                         SmallVector<Requirement, 2>,
+                                         SmallVector<TypeLoc, 2>, bool),
+              Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, DistributedModuleIsAvailableRequest,
               bool(ModuleDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, InheritedTypeRequest,
@@ -288,6 +301,9 @@ SWIFT_REQUEST(TypeChecker, ProtocolDependenciesRequest,
 SWIFT_REQUEST(TypeChecker, RequirementSignatureRequestRQM,
               RequirementSignature(ProtocolDecl *), Cached,
               NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, RequirementSignatureRequestGSB,
+              RequirementSignature(ProtocolDecl *), Cached,
+              NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, RequirementSignatureRequest,
               RequirementSignature(ProtocolDecl *), SeparatelyCached,
               NoLocationInfo)