Merge pull request #39990 from slavapestov/completely-encapsulate-gsb

Completely encapsulate GenericSignatureBuilder

Author: slavapestov

include/swift/AST/GenericSignature.h

@@ -114,7 +114,9 @@ class GenericSignature {
 
 public:
   /// Create a new generic signature with the given type parameters and
-  /// requirements.
+  /// requirements. The requirements must already be minimal and canonical;
+  /// to build a signature from an arbitrary set of requirements, use
+  /// swift::buildGenericSignature() instead.
   static GenericSignature get(ArrayRef<GenericTypeParamType *> params,
                               ArrayRef<Requirement> requirements,
                               bool isKnownCanonical = false);
@@ -494,6 +496,31 @@ int compareAssociatedTypes(AssociatedTypeDecl *assocType1,
 
 int compareDependentTypes(Type type1, Type type2);
 
+/// Verify the correctness of the given generic signature.
+///
+/// This routine will test that the given generic signature is both minimal
+/// and canonical, emitting errors if it is not.
+void validateGenericSignature(ASTContext &context,
+                              GenericSignature sig);
+
+/// Verify all of the generic signatures in the given module.
+void validateGenericSignaturesInModule(ModuleDecl *module);
+
+/// Build a generic signature from the given requirements, which are not
+/// required to be minimal or canonical, and may contain unresolved
+/// DependentMemberTypes.
+///
+/// If \p baseSignature is non-null, the new parameters and requirements
+/// are added on; existing requirements of the base signature might become
+/// redundant.
+///
+/// If \p baseSignature is null, build a new signature from scratch.
+GenericSignature buildGenericSignature(
+    ASTContext &ctx,
+    GenericSignature baseSignature,
+    SmallVector<GenericTypeParamType *, 2> addedParameters,
+    SmallVector<Requirement, 2> addedRequirements);
+
 } // end namespace swift
 
 namespace llvm {

include/swift/AST/TypeCheckRequests.h

@@ -1411,11 +1411,17 @@ class ClassAncestryFlagsRequest :
 
 void simple_display(llvm::raw_ostream &out, AncestryFlags value);
 
+/// AbstractGenericSignatureRequest and InferredGenericSignatureRequest
+/// return this type, which stores a GenericSignature together with a bit
+/// indicating if there were any errors detected in the original
+/// requirements.
+using GenericSignatureWithError = llvm::PointerIntPair<GenericSignature, 1>;
+
 class AbstractGenericSignatureRequest :
     public SimpleRequest<AbstractGenericSignatureRequest,
-                         GenericSignature (const GenericSignatureImpl *,
-                                           SmallVector<GenericTypeParamType *, 2>,
-                                           SmallVector<Requirement, 2>),
+                         GenericSignatureWithError (const GenericSignatureImpl *,
+                                                    SmallVector<GenericTypeParamType *, 2>,
+                                                    SmallVector<Requirement, 2>),
                          RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -1424,7 +1430,7 @@ class AbstractGenericSignatureRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  GenericSignature
+  GenericSignatureWithError
   evaluate(Evaluator &evaluator,
            const GenericSignatureImpl *baseSignature,
            SmallVector<GenericTypeParamType *, 2> addedParameters,
@@ -1442,13 +1448,13 @@ class AbstractGenericSignatureRequest :
 
 class InferredGenericSignatureRequest :
     public SimpleRequest<InferredGenericSignatureRequest,
-                         GenericSignature (ModuleDecl *,
-                                           const GenericSignatureImpl *,
-                                           GenericParamList *,
-                                           WhereClauseOwner,
-                                           SmallVector<Requirement, 2>,
-                                           SmallVector<TypeLoc, 2>,
-                                           bool),
+                         GenericSignatureWithError (ModuleDecl *,
+                                                    const GenericSignatureImpl *,
+                                                    GenericParamList *,
+                                                    WhereClauseOwner,
+                                                    SmallVector<Requirement, 2>,
+                                                    SmallVector<TypeLoc, 2>,
+                                                    bool),
                          RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -1457,7 +1463,7 @@ class InferredGenericSignatureRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  GenericSignature
+  GenericSignatureWithError
   evaluate(Evaluator &evaluator,
            ModuleDecl *parentModule,
            const GenericSignatureImpl *baseSignature,

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -16,9 +16,9 @@
 //===----------------------------------------------------------------------===//
 
 SWIFT_REQUEST(TypeChecker, AbstractGenericSignatureRequest,
-              GenericSignature (const GenericSignatureImpl *,
-                                SmallVector<GenericTypeParamType *, 2>,
-                                SmallVector<Requirement, 2>),
+              GenericSignatureWithError (const GenericSignatureImpl *,
+                                         SmallVector<GenericTypeParamType *, 2>,
+                                         SmallVector<Requirement, 2>),
               Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, ApplyAccessNoteRequest,
               evaluator::SideEffect(ValueDecl *), Cached, NoLocationInfo)
@@ -131,12 +131,12 @@ SWIFT_REQUEST(TypeChecker, HasImplementationOnlyImportsRequest,
 SWIFT_REQUEST(TypeChecker, ModuleLibraryLevelRequest,
               LibraryLevel(ModuleDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, InferredGenericSignatureRequest,
-              GenericSignature (ModuleDecl *,
-                                const GenericSignatureImpl *,
-                                GenericParamList *,
-                                WhereClauseOwner,
-                                SmallVector<Requirement, 2>,
-                                SmallVector<TypeLoc, 2>, bool),
+              GenericSignatureWithError (ModuleDecl *,
+                                         const GenericSignatureImpl *,
+                                         GenericParamList *,
+                                         WhereClauseOwner,
+                                         SmallVector<Requirement, 2>,
+                                         SmallVector<TypeLoc, 2>, bool),
               Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, DistributedModuleIsAvailableRequest,
               bool(ModuleDecl *), Cached, NoLocationInfo)

lib/AST/ASTContext.cpp

@@ -17,6 +17,7 @@
 #include "swift/AST/ASTContext.h"
 #include "ClangTypeConverter.h"
 #include "ForeignRepresentationInfo.h"
+#include "GenericSignatureBuilder.h"
 #include "SubstitutionMapStorage.h"
 #include "swift/AST/ClangModuleLoader.h"
 #include "swift/AST/ConcreteDeclRef.h"
@@ -28,7 +29,6 @@
 #include "swift/AST/ForeignErrorConvention.h"
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/GenericSignature.h"
-#include "swift/AST/GenericSignatureBuilder.h"
 #include "swift/AST/ImportCache.h"
 #include "swift/AST/IndexSubset.h"
 #include "swift/AST/KnownProtocols.h"
@@ -4253,13 +4253,11 @@ OpaqueTypeArchetypeType::get(OpaqueTypeDecl *Decl, unsigned ordinal,
   }
 # endif
 #endif
-  auto signature = evaluateOrDefault(
-      ctx.evaluator,
-      AbstractGenericSignatureRequest{
-        Decl->getOpaqueInterfaceGenericSignature().getPointer(),
+  auto signature = buildGenericSignature(
+        ctx,
+        Decl->getOpaqueInterfaceGenericSignature(),
         /*genericParams=*/{ },
-        std::move(newRequirements)},
-      nullptr);
+        std::move(newRequirements));
 
   auto reqs = signature->getLocalRequirements(opaqueParamType);
   auto superclass = reqs.superclass;
@@ -5024,10 +5022,10 @@ CanGenericSignature ASTContext::getOpenedArchetypeSignature(Type type) {
   auto genericParam = GenericTypeParamType::get(0, 0, *this);
   Requirement requirement(RequirementKind::Conformance, genericParam,
                           existential);
-  auto genericSig = evaluateOrDefault(
-      evaluator,
-      AbstractGenericSignatureRequest{nullptr, {genericParam}, {requirement}},
-      GenericSignature());
+  auto genericSig = buildGenericSignature(*this,
+                                          GenericSignature(),
+                                          {genericParam},
+                                          {requirement});
 
   CanGenericSignature canGenericSig(genericSig);
 
@@ -5125,13 +5123,9 @@ ASTContext::getOverrideGenericSignature(const ValueDecl *base,
     }
   }
 
-  auto genericSig = evaluateOrDefault(
-      evaluator,
-      AbstractGenericSignatureRequest{
-        derivedClassSig.getPointer(),
-        std::move(addedGenericParams),
-        std::move(addedRequirements)},
-      GenericSignature());
+  auto genericSig = buildGenericSignature(*this, derivedClassSig,
+                                          std::move(addedGenericParams),
+                                          std::move(addedRequirements));
   getImpl().overrideSigCache.insert(std::make_pair(key, genericSig));
   return genericSig;
 }

lib/AST/ASTDemangler.cpp

@@ -897,12 +897,8 @@ CanGenericSignature ASTBuilder::demangleGenericSignature(
 
   decodeRequirement<BuiltType, BuiltRequirement, BuiltLayoutConstraint,
                     ASTBuilder>(node, requirements, *this);
-  return evaluateOrDefault(Ctx.evaluator,
-                           AbstractGenericSignatureRequest{
-                               nominalDecl->getGenericSignature().getPointer(),
-                               {},
-                               std::move(requirements)},
-                           GenericSignature())
+  return buildGenericSignature(Ctx, nominalDecl->getGenericSignature(),
+                               {}, std::move(requirements))
       .getCanonicalSignature();
 }
 

lib/AST/AutoDiff.cpp

@@ -273,12 +273,9 @@ GenericSignature autodiff::getConstrainedDerivativeGenericSignature(
       requirements.push_back(req);
     }
   }
-  return evaluateOrDefault(
-      ctx.evaluator,
-      AbstractGenericSignatureRequest{derivativeGenSig.getPointer(),
-                                      /*addedGenericParams*/ {},
-                                      std::move(requirements)},
-      nullptr);
+  return buildGenericSignature(ctx, derivativeGenSig,
+                               /*addedGenericParams*/ {},
+                               std::move(requirements));
 }
 
 // Given the rest of a `Builtin.applyDerivative_{jvp|vjp}` or

lib/AST/Builtins.cpp

@@ -305,12 +305,10 @@ synthesizeGenericSignature(SynthesisContext &SC,
   CollectGenericParams collector(SC);
   list.Params.visit(collector);
 
-  return evaluateOrDefault(
-    SC.Context.evaluator,
-    AbstractGenericSignatureRequest{
-      nullptr, std::move(collector.GenericParamTypes),
-               std::move(collector.AddedRequirements)},
-    nullptr);
+  return buildGenericSignature(SC.Context,
+                               GenericSignature(),
+                               std::move(collector.GenericParamTypes),
+                               std::move(collector.AddedRequirements));
 }
 
 /// Build a builtin function declaration.
@@ -671,8 +669,8 @@ namespace {
     bool Async = false;
     BuiltinThrowsKind Throws = BuiltinThrowsKind::None;
 
-    // Accumulate params and requirements here, so that we can make the
-    // appropriate `AbstractGenericSignatureRequest` when `build()` is called.
+    // Accumulate params and requirements here, so that we can call
+    // `buildGenericSignature()` when `build()` is called.
     SmallVector<GenericTypeParamType *, 2> genericParamTypes;
     SmallVector<Requirement, 2> addedRequirements;
 
@@ -727,11 +725,10 @@ namespace {
     }
 
     FuncDecl *build(Identifier name) {
-      auto GenericSig = evaluateOrDefault(
-        Context.evaluator,
-        AbstractGenericSignatureRequest{
-          nullptr, std::move(genericParamTypes), std::move(addedRequirements)},
-        nullptr);
+      auto GenericSig = buildGenericSignature(
+          Context, GenericSignature(),
+          std::move(genericParamTypes),
+          std::move(addedRequirements));
       return getBuiltinGenericFunction(name, InterfaceParams,
                                        InterfaceResult,
                                        TheGenericParamList, GenericSig,