[NFC] A Handful of Sweeping Evaluator Cleanups

include/swift/AST/AccessRequests.h

@@ -41,8 +41,7 @@ class AccessLevelRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<AccessLevel> evaluate(Evaluator &evaluator,
-                                       ValueDecl *decl) const;
+  AccessLevel evaluate(Evaluator &evaluator, ValueDecl *decl) const;
 
 public:
   // Separate caching.
@@ -65,8 +64,7 @@ class SetterAccessLevelRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<AccessLevel>
-  evaluate(Evaluator &evaluator, AbstractStorageDecl *decl) const;
+  AccessLevel evaluate(Evaluator &evaluator, AbstractStorageDecl *decl) const;
 
 public:
   // Separate caching.
@@ -88,8 +86,7 @@ class DefaultAndMaxAccessLevelRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<DefaultAndMax>
-  evaluate(Evaluator &evaluator, ExtensionDecl *decl) const;
+  DefaultAndMax evaluate(Evaluator &evaluator, ExtensionDecl *decl) const;
 
 public:
   // Separate caching.

include/swift/AST/Evaluator.h

@@ -54,7 +54,7 @@ using AbstractRequestFunction = void(void);
 /// Form the specific request function for the given request type.
 template<typename Request>
 using RequestFunction =
-  llvm::Expected<typename Request::OutputType>(const Request &, Evaluator &);
+  typename Request::OutputType(const Request &, Evaluator &);
 
 /// Pretty stack trace handler for an arbitrary request.
 template<typename Request>

include/swift/AST/IRGenRequests.h

@@ -124,7 +124,7 @@ class IRGenSourceFileRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<std::unique_ptr<llvm::Module>>
+  std::unique_ptr<llvm::Module>
   evaluate(Evaluator &evaluator, IRGenDescriptor desc) const;
 
 public:
@@ -142,7 +142,7 @@ class IRGenWholeModuleRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<std::unique_ptr<llvm::Module>>
+  std::unique_ptr<llvm::Module>
   evaluate(Evaluator &evaluator, IRGenDescriptor desc) const;
 
 public:

include/swift/AST/NameLookupRequests.h

@@ -153,7 +153,7 @@ class SuperclassDeclRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<ClassDecl *>
+  ClassDecl *
   evaluate(Evaluator &evaluator, NominalTypeDecl *subject) const;
 
 public:
@@ -197,7 +197,7 @@ class HasMissingDesignatedInitializersRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<bool>
+  bool
   evaluate(Evaluator &evaluator, ClassDecl *subject) const;
 
 public:
@@ -219,7 +219,7 @@ class ExtendedNominalRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<NominalTypeDecl *>
+  NominalTypeDecl *
   evaluate(Evaluator &evaluator, ExtensionDecl *ext) const;
 
 public:
@@ -283,7 +283,7 @@ class CustomAttrNominalRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<NominalTypeDecl *>
+  NominalTypeDecl *
   evaluate(Evaluator &evaluator, CustomAttr *attr, DeclContext *dc) const;
 
 public:
@@ -303,7 +303,7 @@ class GetDestructorRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<DestructorDecl *>
+  DestructorDecl *
   evaluate(Evaluator &evaluator, ClassDecl *classDecl) const;
 
 public:
@@ -324,7 +324,7 @@ class GenericParamListRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<GenericParamList *>
+  GenericParamList *
   evaluate(Evaluator &evaluator, GenericContext *value) const;
 
 public:
@@ -347,7 +347,7 @@ class ExpandASTScopeRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<ast_scope::ASTScopeImpl *>
+  ast_scope::ASTScopeImpl *
   evaluate(Evaluator &evaluator, ast_scope::ASTScopeImpl *,
            ast_scope::ScopeCreator *) const;
 
@@ -407,8 +407,8 @@ class UnqualifiedLookupRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<LookupResult> evaluate(Evaluator &evaluator,
-                                        UnqualifiedLookupDescriptor desc) const;
+  LookupResult evaluate(Evaluator &evaluator,
+                        UnqualifiedLookupDescriptor desc) const;
 };
 
 using QualifiedLookupResult = SmallVector<ValueDecl *, 4>;
@@ -427,7 +427,7 @@ class LookupInModuleRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<QualifiedLookupResult>
+  QualifiedLookupResult
   evaluate(Evaluator &evaluator, const DeclContext *moduleOrFile, DeclName name,
            NLKind lookupKind, namelookup::ResolutionKind resolutionKind,
            const DeclContext *moduleScopeContext) const;
@@ -445,10 +445,10 @@ class AnyObjectLookupRequest
 private:
   friend SimpleRequest;
 
-  llvm::Expected<QualifiedLookupResult> evaluate(Evaluator &evaluator,
-                                                 const DeclContext *dc,
-                                                 DeclNameRef name,
-                                                 NLOptions options) const;
+  QualifiedLookupResult evaluate(Evaluator &evaluator,
+                                 const DeclContext *dc,
+                                 DeclNameRef name,
+                                 NLOptions options) const;
 };
 
 class ModuleQualifiedLookupRequest
@@ -464,10 +464,10 @@ class ModuleQualifiedLookupRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<QualifiedLookupResult> evaluate(Evaluator &evaluator,
-                                                 const DeclContext *DC,
-                                                 ModuleDecl *mod, DeclNameRef name,
-                                                 NLOptions opts) const;
+  QualifiedLookupResult evaluate(Evaluator &evaluator,
+                                 const DeclContext *DC,
+                                 ModuleDecl *mod, DeclNameRef name,
+                                 NLOptions opts) const;
 };
 
 class QualifiedLookupRequest
@@ -483,7 +483,7 @@ class QualifiedLookupRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<QualifiedLookupResult>
+  QualifiedLookupResult
   evaluate(Evaluator &evaluator, const DeclContext *DC,
            SmallVector<NominalTypeDecl *, 4> decls,
            DeclNameRef name,
@@ -534,7 +534,7 @@ class DirectLookupRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<TinyPtrVector<ValueDecl *>>
+  TinyPtrVector<ValueDecl *>
   evaluate(Evaluator &evaluator, DirectLookupDescriptor desc) const;
 };
 
@@ -609,8 +609,8 @@ class LookupOperatorRequest
                        CacheKind::Uncached>;
 
   // Evaluation.
-  llvm::Expected<OperatorType *> evaluate(Evaluator &evaluator,
-                                          OperatorLookupDescriptor desc) const;
+  OperatorType *
+  evaluate(Evaluator &evaluator, OperatorLookupDescriptor desc) const;
 };
 
 using LookupPrefixOperatorRequest = LookupOperatorRequest<PrefixOperatorDecl>;
@@ -631,7 +631,7 @@ class DirectOperatorLookupRequest
 private:
   friend SimpleRequest;
 
-  llvm::Expected<TinyPtrVector<OperatorDecl *>>
+  TinyPtrVector<OperatorDecl *>
   evaluate(Evaluator &evaluator, OperatorLookupDescriptor descriptor,
            OperatorFixity fixity) const;
 };
@@ -649,7 +649,7 @@ class DirectPrecedenceGroupLookupRequest
 private:
   friend SimpleRequest;
 
-  llvm::Expected<TinyPtrVector<PrecedenceGroupDecl *>>
+  TinyPtrVector<PrecedenceGroupDecl *>
   evaluate(Evaluator &evaluator, OperatorLookupDescriptor descriptor) const;
 };
 
@@ -694,7 +694,7 @@ class LookupConformanceInModuleRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<ProtocolConformanceRef> evaluate(
+  ProtocolConformanceRef evaluate(
       Evaluator &evaluator, LookupConformanceDescriptor desc) const;
 };
 

include/swift/AST/SILGenRequests.h

@@ -89,7 +89,7 @@ class SILGenSourceFileRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<std::unique_ptr<SILModule>>
+  std::unique_ptr<SILModule>
   evaluate(Evaluator &evaluator, SILGenDescriptor desc) const;
 
 public:
@@ -107,7 +107,7 @@ class SILGenWholeModuleRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<std::unique_ptr<SILModule>>
+  std::unique_ptr<SILModule>
   evaluate(Evaluator &evaluator, SILGenDescriptor desc) const;
 
 public:

include/swift/AST/SILOptimizerRequests.h

@@ -50,7 +50,7 @@ llvm::hash_code hash_value(const SILPipelineExecutionDescriptor &desc);
 /// Executes a SIL pipeline plan on a SIL module.
 class ExecuteSILPipelineRequest
     : public SimpleRequest<ExecuteSILPipelineRequest,
-                           bool(SILPipelineExecutionDescriptor),
+                           evaluator::SideEffect(SILPipelineExecutionDescriptor),
                            CacheKind::Uncached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -59,8 +59,8 @@ class ExecuteSILPipelineRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<bool> evaluate(Evaluator &evaluator,
-                                SILPipelineExecutionDescriptor desc) const;
+  evaluator::SideEffect
+  evaluate(Evaluator &evaluator, SILPipelineExecutionDescriptor desc) const;
 };
 
 void simple_display(llvm::raw_ostream &out,

include/swift/AST/SILOptimizerTypeIDZone.def

@@ -15,4 +15,5 @@
 //===----------------------------------------------------------------------===//
 
 SWIFT_REQUEST(SILOptimizer, ExecuteSILPipelineRequest,
-              bool(SILPipelineExecutionDescriptor), Uncached, NoLocationInfo)
+              evaluator::SideEffect(SILPipelineExecutionDescriptor),
+              Uncached, NoLocationInfo)

include/swift/AST/SimpleRequest.h

@@ -148,9 +148,9 @@ SourceLoc extractNearestSourceLoc(const std::tuple<First, Rest...> &value) {
 ///
 /// The \c Derived class needs to implement several operations. The most
 /// important one takes an evaluator and the input values, then computes the
-/// final result, optionally bubbling up errors from recursive evaulations:
+/// final result:
 /// \code
-///   llvm::Expected<Output> evaluate(Evaluator &evaluator, Inputs...) const;
+///   Output evaluate(Evaluator &evaluator, Inputs...) const;
 /// \endcode
 ///
 /// Cycle diagnostics can be handled in one of two ways. Either the \c Derived
@@ -194,7 +194,7 @@ class SimpleRequest<Derived, Output(Inputs...), Caching> {
   }
 
   template<size_t ...Indices>
-  llvm::Expected<Output>
+  Output
   callDerived(Evaluator &evaluator, std::index_sequence<Indices...>) const {
     static_assert(sizeof...(Indices) > 0, "Subclass must define evaluate()");
     return asDerived().evaluate(evaluator, std::get<Indices>(storage)...);
@@ -214,7 +214,7 @@ class SimpleRequest<Derived, Output(Inputs...), Caching> {
     : storage(inputs...) { }
 
   /// Request evaluation function that will be registered with the evaluator.
-  static llvm::Expected<OutputType>
+  static OutputType
   evaluateRequest(const Derived &request, Evaluator &evaluator) {
     return request.callDerived(evaluator,
                                std::index_sequence_for<Inputs...>());

include/swift/AST/TBDGenRequests.h

@@ -92,8 +92,7 @@ class GenerateTBDRequest
   friend SimpleRequest;
 
   // Evaluation.
-  llvm::Expected<TBDFileAndSymbols> evaluate(Evaluator &evaluator,
-                                             TBDGenDescriptor desc) const;
+  TBDFileAndSymbols evaluate(Evaluator &evaluator, TBDGenDescriptor desc) const;
 };
 
 /// Report that a request of the given kind is being evaluated, so it