swiftlang · dan-zheng · Jan 12, 2020 · Jan 9, 2020 · Jan 9, 2020 · Jan 10, 2020
diff --git a/include/swift/AST/GenericSignature.h b/include/swift/AST/GenericSignature.h
@@ -93,6 +93,7 @@ class ConformanceAccessPath {
   SWIFT_DEBUG_DUMP;
 };
 
+class CanGenericSignature;
 class GenericSignatureImpl;
 class GenericTypeParamType;
 
@@ -140,6 +141,10 @@ class GenericSignature {
   SWIFT_DEBUG_DUMP;
   std::string getAsString() const;
 
+  /// Returns the canonical generic signature, or \c nullptr if the underlying
+  /// pointer is \c nullptr. The result is cached.
+  CanGenericSignature getCanonicalSignature() const;
+
   // Support for FoldingSet.
   void Profile(llvm::FoldingSetNodeID &id) const;
 
@@ -300,8 +305,8 @@ class alignas(1 << TypeAlignInBits) GenericSignatureImpl final
   bool isCanonical() const;
 
   ASTContext &getASTContext() const;
-  
-  /// Canonicalize the components of a generic signature.
+
+  /// Returns the canonical generic signature. The result is cached.
   CanGenericSignature getCanonicalSignature() const;
 
   /// Retrieve the generic signature builder for the given generic signature.

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
@@ -1525,7 +1525,7 @@ static AllocationArena getArena(GenericSignature genericSig) {
 void ASTContext::registerGenericSignatureBuilder(
                                        GenericSignature sig,
                                        GenericSignatureBuilder &&builder) {
-  auto canSig = sig->getCanonicalSignature();
+  auto canSig = sig.getCanonicalSignature();
   auto arena = getArena(sig);
   auto &genericSignatureBuilders =
       getImpl().getArena(arena).GenericSignatureBuilders;
@@ -1564,12 +1564,12 @@ GenericSignatureBuilder *ASTContext::getOrCreateGenericSignatureBuilder(
   auto builderSig =
     builder->computeGenericSignature(SourceLoc(),
                                      /*allowConcreteGenericParams=*/true);
-  if (builderSig->getCanonicalSignature() != sig) {
+  if (builderSig.getCanonicalSignature() != sig) {
     llvm::errs() << "ERROR: generic signature builder is not idempotent.\n";
     llvm::errs() << "Original generic signature   : ";
     sig->print(llvm::errs());
     llvm::errs() << "\nReprocessed generic signature: ";
-    auto reprocessedSig = builderSig->getCanonicalSignature();
+    auto reprocessedSig = builderSig.getCanonicalSignature();
 
     reprocessedSig->print(llvm::errs());
     llvm::errs() << "\n";
@@ -3277,9 +3277,9 @@ SILFunctionType::SILFunctionType(
             "types and substitutions");
 
   if (substitutions) {
-    assert(substitutions.getGenericSignature()->getCanonicalSignature()
-             == genericSig->getCanonicalSignature()
-           && "substitutions must match generic signature");
+    assert(substitutions.getGenericSignature().getCanonicalSignature() ==
+               genericSig.getCanonicalSignature() &&
+           "substitutions must match generic signature");
   }
 
   if (genericSig) {

diff --git a/lib/AST/ASTDemangler.cpp b/lib/AST/ASTDemangler.cpp
@@ -454,7 +454,7 @@ Type ASTBuilder::createImplFunctionType(
     ArrayRef<Demangle::ImplFunctionResult<Type>> results,
     Optional<Demangle::ImplFunctionResult<Type>> errorResult,
     ImplFunctionTypeFlags flags) {
-  GenericSignature genericSig = GenericSignature();
+  GenericSignature genericSig;
 
   SILCoroutineKind funcCoroutineKind = SILCoroutineKind::None;
   ParameterConvention funcCalleeConvention =
@@ -865,12 +865,13 @@ CanGenericSignature ASTBuilder::demangleGenericSignature(
     }
   }
 
-  return evaluateOrDefault(
-      Ctx.evaluator,
-      AbstractGenericSignatureRequest{
-        nominalDecl->getGenericSignature().getPointer(), { },
-        std::move(requirements)},
-      GenericSignature())->getCanonicalSignature();
+  return evaluateOrDefault(Ctx.evaluator,
+                           AbstractGenericSignatureRequest{
+                               nominalDecl->getGenericSignature().getPointer(),
+                               {},
+                               std::move(requirements)},
+                           GenericSignature())
+      .getCanonicalSignature();
 }
 
 DeclContext *
@@ -980,8 +981,7 @@ ASTBuilder::findDeclContext(NodePointer node) {
         continue;
       }
 
-      if (ext->getGenericSignature()->getCanonicalSignature()
-          == genericSig) {
+      if (ext->getGenericSignature().getCanonicalSignature() == genericSig) {
         return ext;
       }
     }

diff --git a/lib/AST/ASTMangler.cpp b/lib/AST/ASTMangler.cpp
@@ -360,7 +360,7 @@ std::string ASTMangler::mangleReabstractionThunkHelper(
   assert(ThunkType->getSubstitutions().empty() && "not implemented");
   GenericSignature GenSig = ThunkType->getSubstGenericSignature();
   if (GenSig)
-    CurGenericSignature = GenSig->getCanonicalSignature();
+    CurGenericSignature = GenSig.getCanonicalSignature();
 
   beginMangling();
   appendType(FromType);
@@ -1199,7 +1199,7 @@ void ASTMangler::bindGenericParameters(CanGenericSignature sig) {
 /// Bind the generic parameters from the given context and its parents.
 void ASTMangler::bindGenericParameters(const DeclContext *DC) {
   if (auto sig = DC->getGenericSignatureOfContext())
-    bindGenericParameters(sig->getCanonicalSignature());
+    bindGenericParameters(sig.getCanonicalSignature());
 }
 
 void ASTMangler::appendFlatGenericArgs(SubstitutionMap subs) {
@@ -2121,7 +2121,7 @@ void ASTMangler::appendTypeListElement(Identifier name, Type elementType,
 
 bool ASTMangler::appendGenericSignature(GenericSignature sig,
                                         GenericSignature contextSig) {
-  auto canSig = sig->getCanonicalSignature();
+  auto canSig = sig.getCanonicalSignature();
   CurGenericSignature = canSig;
 
   unsigned initialParamDepth;
@@ -2131,7 +2131,7 @@ bool ASTMangler::appendGenericSignature(GenericSignature sig,
   if (contextSig) {
     // If the signature is the same as the context signature, there's nothing
     // to do.
-    if (contextSig->getCanonicalSignature() == canSig) {
+    if (contextSig.getCanonicalSignature() == canSig) {
       return false;
     }
 
@@ -2442,8 +2442,8 @@ CanType ASTMangler::getDeclTypeForMangling(
 
 void ASTMangler::appendDeclType(const ValueDecl *decl, bool isFunctionMangling) {
   Mod = decl->getModuleContext();
-  GenericSignature genericSig = GenericSignature();
-  GenericSignature parentGenericSig = GenericSignature();
+  GenericSignature genericSig;
+  GenericSignature parentGenericSig;
   auto type = getDeclTypeForMangling(decl, genericSig, parentGenericSig);
 
   if (AnyFunctionType *FuncTy = type->getAs<AnyFunctionType>()) {
@@ -2559,7 +2559,7 @@ void ASTMangler::appendEntity(const ValueDecl *decl) {
 
 void
 ASTMangler::appendProtocolConformance(const ProtocolConformance *conformance) {
-  GenericSignature contextSig = GenericSignature();
+  GenericSignature contextSig;
   auto topLevelContext =
       conformance->getDeclContext()->getModuleScopeContext();
   Mod = topLevelContext->getParentModule();
@@ -2702,7 +2702,7 @@ void ASTMangler::appendConcreteProtocolConformance(
   auto shouldUseConformanceSig = !CurGenericSignature && conformanceSig;
   llvm::SaveAndRestore<CanGenericSignature> savedSignature(
       CurGenericSignature, shouldUseConformanceSig
-                               ? conformanceSig->getCanonicalSignature()
+                               ? conformanceSig.getCanonicalSignature()
                                : CurGenericSignature);
 
   // Conforming type.
@@ -2745,7 +2745,7 @@ void ASTMangler::appendConcreteProtocolConformance(
         // Append the conformance access path with the signature of the opaque type.
         {
           llvm::SaveAndRestore<CanGenericSignature> savedSignature(
-              CurGenericSignature, opaqueSignature->getCanonicalSignature());
+              CurGenericSignature, opaqueSignature.getCanonicalSignature());
           appendDependentProtocolConformance(conformanceAccessPath);
         }
         appendType(canType);

diff --git a/lib/AST/GenericSignature.cpp b/lib/AST/GenericSignature.cpp
@@ -167,12 +167,12 @@ GenericSignatureBuilder *GenericSignatureImpl::getGenericSignatureBuilder() {
 }
 
 bool GenericSignatureImpl::isEqual(GenericSignature Other) {
-  return getCanonicalSignature() == Other.getPointer()->getCanonicalSignature();
+  return getCanonicalSignature() == Other.getCanonicalSignature();
 }
 
 bool GenericSignatureImpl::isCanonical() const {
-  if (CanonicalSignatureOrASTContext.is<ASTContext*>()) return true;
-
+  if (CanonicalSignatureOrASTContext.is<ASTContext *>())
+    return true;
   return getCanonicalSignature().getPointer() == this;
 }
 
@@ -310,6 +310,14 @@ CanGenericSignature::getCanonical(TypeArrayView<GenericTypeParamType> params,
   return CanGenericSignature(canSig);
 }
 
+CanGenericSignature GenericSignature::getCanonicalSignature() const {
+  // If the underlying pointer is null, return `CanGenericSignature()`.
+  if (isNull())
+    return CanGenericSignature();
+  // Otherwise, return the canonical signature of the underlying pointer.
+  return getPointer()->getCanonicalSignature();
+}
+
 CanGenericSignature GenericSignatureImpl::getCanonicalSignature() const {
   // If we haven't computed the canonical signature yet, do so now.
   if (CanonicalSignatureOrASTContext.isNull()) {

diff --git a/lib/AST/GenericSignatureBuilder.cpp b/lib/AST/GenericSignatureBuilder.cpp
@@ -7276,7 +7276,7 @@ void GenericSignatureBuilder::verifyGenericSignature(ASTContext &context,
     }
 
     // Canonicalize the signature to check that it is canonical.
-    (void)newSig->getCanonicalSignature();
+    (void)newSig.getCanonicalSignature();
   }
 }
 
@@ -7298,7 +7298,7 @@ void GenericSignatureBuilder::verifyGenericSignaturesInModule(
   for (auto genericSig : allGenericSignatures) {
     // Check whether this is the first time we've checked this (canonical)
     // signature.
-    auto canGenericSig = genericSig->getCanonicalSignature();
+    auto canGenericSig = genericSig.getCanonicalSignature();
     if (!knownGenericSignatures.insert(canGenericSig).second) continue;
 
     verifyGenericSignature(context, canGenericSig);
@@ -7367,7 +7367,7 @@ AbstractGenericSignatureRequest::evaluate(
   // generic signature builder.
   if (!isCanonicalRequest(baseSignature, addedParameters, addedRequirements)) {
     // Canonicalize the inputs so we can form the canonical request.
-    GenericSignature canBaseSignature = GenericSignature();
+    GenericSignature canBaseSignature;
     if (baseSignature)
       canBaseSignature = baseSignature->getCanonicalSignature();
 

diff --git a/lib/AST/ProtocolConformance.cpp b/lib/AST/ProtocolConformance.cpp
@@ -547,8 +547,8 @@ void NormalProtocolConformance::differenceAndStoreConditionalRequirements()
   }
 
   auto extensionSig = ext->getGenericSignature();
-  auto canExtensionSig = extensionSig->getCanonicalSignature();
-  auto canTypeSig = typeSig->getCanonicalSignature();
+  auto canExtensionSig = extensionSig.getCanonicalSignature();
+  auto canTypeSig = typeSig.getCanonicalSignature();
   if (canTypeSig == canExtensionSig) {
     success({});
     return;

diff --git a/lib/AST/RequirementEnvironment.cpp b/lib/AST/RequirementEnvironment.cpp
@@ -140,7 +140,7 @@ RequirementEnvironment::RequirementEnvironment(
       reqSig->getRequirements().size() == 1) {
     syntheticSignature = conformanceDC->getGenericSignatureOfContext();
     if (syntheticSignature) {
-      syntheticSignature = syntheticSignature->getCanonicalSignature();
+      syntheticSignature = syntheticSignature.getCanonicalSignature();
       syntheticEnvironment =
         syntheticSignature->getGenericEnvironment();
     }

diff --git a/lib/AST/SubstitutionMap.cpp b/lib/AST/SubstitutionMap.cpp
@@ -152,7 +152,7 @@ bool SubstitutionMap::isCanonical() const {
 SubstitutionMap SubstitutionMap::getCanonical() const {
   if (empty()) return *this;
 
-  auto canonicalSig = getGenericSignature()->getCanonicalSignature();
+  auto canonicalSig = getGenericSignature().getCanonicalSignature();
   SmallVector<Type, 4> replacementTypes;
   for (Type replacementType : getReplacementTypesBuffer()) {
     if (replacementType)

diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
@@ -1193,7 +1193,7 @@ CanType TypeBase::computeCanonicalType() {
 
     CanGenericSignature genericSig;
     if (auto *genericFnTy = dyn_cast<GenericFunctionType>(this))
-      genericSig = genericFnTy->getGenericSignature()->getCanonicalSignature();
+      genericSig = genericFnTy->getGenericSignature().getCanonicalSignature();
 
     // Transform the parameter and result types.
     SmallVector<AnyFunctionType::Param, 8> canParams;
@@ -2570,8 +2570,8 @@ static bool matches(CanType t1, CanType t2, TypeMatchOptions matchMode,
   if (matchMode.contains(TypeMatchFlags::AllowCompatibleOpaqueTypeArchetypes))
     if (auto opaque1 = t1->getAs<OpaqueTypeArchetypeType>())
       if (auto opaque2 = t2->getAs<OpaqueTypeArchetypeType>())
-        return opaque1->getBoundSignature()->getCanonicalSignature() ==
-                   opaque2->getBoundSignature()->getCanonicalSignature() &&
+        return opaque1->getBoundSignature().getCanonicalSignature() ==
+                   opaque2->getBoundSignature().getCanonicalSignature() &&
                opaque1->getInterfaceType()->getCanonicalType()->matches(
                    opaque2->getInterfaceType()->getCanonicalType(), matchMode);
 
@@ -3526,7 +3526,7 @@ static Type substGenericFunctionType(GenericFunctionType *genericFnType,
     requirements.push_back(*substReqt);
   }
 
-  GenericSignature genericSig = GenericSignature();
+  GenericSignature genericSig;
   if (anySemanticChanges) {
     // If there were semantic changes, we need to build a new generic
     // signature.

diff --git a/lib/ClangImporter/ImportType.cpp b/lib/ClangImporter/ImportType.cpp
@@ -608,7 +608,7 @@ namespace {
     importObjCTypeParamDecl(const clang::ObjCTypeParamDecl *objcTypeParamDecl) {
       // Pull the corresponding generic type parameter from the imported class.
       const auto *typeParamContext = objcTypeParamDecl->getDeclContext();
-      GenericSignature genericSig = GenericSignature();
+      GenericSignature genericSig;
       if (auto *category =
             dyn_cast<clang::ObjCCategoryDecl>(typeParamContext)) {
         auto ext = cast_or_null<ExtensionDecl>(

diff --git a/lib/IRGen/GenArchetype.cpp b/lib/IRGen/GenArchetype.cpp
@@ -189,7 +189,7 @@ llvm::Value *irgen::emitArchetypeWitnessTableRef(IRGenFunction &IGF,
   // concretely available; we really ought to be comparing the full paths
   // to this conformance from concrete sources.
 
-  auto signature = environment->getGenericSignature()->getCanonicalSignature();
+  auto signature = environment->getGenericSignature().getCanonicalSignature();
   auto archetypeDepType = archetype->getInterfaceType();
 
   auto astPath = signature->getConformanceAccessPath(archetypeDepType,
@@ -414,21 +414,22 @@ withOpaqueTypeGenericArgs(IRGenFunction &IGF,
   } else {
     SmallVector<llvm::Value *, 4> args;
     SmallVector<llvm::Type *, 4> types;
-    
+
     enumerateGenericSignatureRequirements(
-      opaqueDecl->getGenericSignature()->getCanonicalSignature(),
-      [&](GenericRequirement reqt) {
-        auto ty = reqt.TypeParameter.subst(archetype->getSubstitutions())
-          ->getCanonicalType(opaqueDecl->getGenericSignature());
-        if (reqt.Protocol) {
-          auto ref = ProtocolConformanceRef(reqt.Protocol)
-            .subst(reqt.TypeParameter, archetype->getSubstitutions());
-          args.push_back(emitWitnessTableRef(IGF, ty, ref));
-        } else {
-          args.push_back(IGF.emitAbstractTypeMetadataRef(ty));
-        }
-        types.push_back(args.back()->getType());
-      });
+        opaqueDecl->getGenericSignature().getCanonicalSignature(),
+        [&](GenericRequirement reqt) {
+          auto ty = reqt.TypeParameter.subst(archetype->getSubstitutions())
+                        ->getCanonicalType(opaqueDecl->getGenericSignature());
+          if (reqt.Protocol) {
+            auto ref =
+                ProtocolConformanceRef(reqt.Protocol)
+                    .subst(reqt.TypeParameter, archetype->getSubstitutions());
+            args.push_back(emitWitnessTableRef(IGF, ty, ref));
+          } else {
+            args.push_back(IGF.emitAbstractTypeMetadataRef(ty));
+          }
+          types.push_back(args.back()->getType());
+        });
     auto bufTy = llvm::StructType::get(IGF.IGM.LLVMContext, types);
     alloca = IGF.createAlloca(bufTy, IGF.IGM.getPointerAlignment());
     allocaSize = IGF.IGM.getPointerSize() * args.size();

diff --git a/lib/IRGen/GenHeap.cpp b/lib/IRGen/GenHeap.cpp
@@ -1460,7 +1460,7 @@ class FixedBoxTypeInfoBase : public BoxTypeInfo {
 
     auto boxDescriptor = IGF.IGM.getAddrOfBoxDescriptor(
         boxedInterfaceType,
-        env ? env->getGenericSignature()->getCanonicalSignature()
+        env ? env->getGenericSignature().getCanonicalSignature()
             : CanGenericSignature());
     llvm::Value *allocation = IGF.emitUnmanagedAlloc(layout, name,
                                                      boxDescriptor);