AST: The input generic signature of a substitution map can be canonical

Author: slavapestov

include/swift/AST/SubstitutionMap.h

@@ -112,9 +112,8 @@ class SubstitutionMap {
   static SubstitutionMap get(GenericSignature genericSig,
                              InFlightSubstitution &IFS);
 
-  /// Retrieve the generic signature describing the environment in which
-  /// substitutions occur.
-  GenericSignature getGenericSignature() const;
+  /// Retrieve the substitution map's input generic signature.
+  CanGenericSignature getGenericSignature() const;
 
   /// Retrieve the array of protocol conformances, which line up with the
   /// requirements of the generic signature.
@@ -152,7 +151,7 @@ class SubstitutionMap {
   bool isCanonical() const;
 
   /// Return the canonical form of this substitution map.
-  SubstitutionMap getCanonical(bool canonicalizeSignature = true) const;
+  SubstitutionMap getCanonical() const;
 
   /// Apply a substitution to all replacement types in the map. Does not
   /// change keys.

include/swift/SIL/SILCloner.h

@@ -269,8 +269,7 @@ class SILCloner : protected SILInstructionVisitor<ImplClass> {
   }
 
   SubstitutionMap getOpSubstitutionMap(SubstitutionMap Subs) {
-    auto substSubs = asImpl().remapSubstitutionMap(Subs)
-                   .getCanonical(/*canonicalizeSignature*/false);
+    auto substSubs = asImpl().remapSubstitutionMap(Subs).getCanonical();
 
 #ifndef NDEBUG
     for (auto substConf : substSubs.getConformances()) {

lib/AST/ASTContext.cpp

@@ -5372,7 +5372,7 @@ Type OpenedArchetypeType::getAny(Type existential) {
 
 void SubstitutionMap::Storage::Profile(
                                llvm::FoldingSetNodeID &id,
-                               GenericSignature genericSig,
+                               CanGenericSignature genericSig,
                                ArrayRef<Type> replacementTypes,
                                ArrayRef<ProtocolConformanceRef> conformances) {
   id.AddPointer(genericSig.getPointer());
@@ -5388,7 +5388,7 @@ void SubstitutionMap::Storage::Profile(
 }
 
 SubstitutionMap::Storage *SubstitutionMap::Storage::get(
-                            GenericSignature genericSig,
+                            CanGenericSignature genericSig,
                             ArrayRef<Type> replacementTypes,
                             ArrayRef<ProtocolConformanceRef> conformances) {
   // If there is no generic signature, we need no storage.

lib/AST/ASTPrinter.cpp

@@ -7021,7 +7021,7 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
       // pack at the appropriate index.  We only expect to actually do
       // this once for each type, so it's fine to do it in the callback.
       unsigned nextIndex = 0;
-      for (auto *genericParam : params) {
+      for (auto genericParam : params) {
         if (!genericParam->isParameterPack())
           continue;
 

lib/AST/SubstitutionMap.cpp

@@ -43,7 +43,7 @@
 using namespace swift;
 
 SubstitutionMap::Storage::Storage(
-                              GenericSignature genericSig,
+                              CanGenericSignature genericSig,
                               ArrayRef<Type> replacementTypes,
                               ArrayRef<ProtocolConformanceRef> conformances)
   : genericSig(genericSig),
@@ -62,7 +62,8 @@ SubstitutionMap::SubstitutionMap(
                                 GenericSignature genericSig,
                                 ArrayRef<Type> replacementTypes,
                                 ArrayRef<ProtocolConformanceRef> conformances)
-  : storage(Storage::get(genericSig, replacementTypes, conformances)) {
+  : storage(Storage::get(genericSig.getCanonicalSignature(),
+                         replacementTypes, conformances)) {
 #ifndef NDEBUG
   if (genericSig->getASTContext().LangOpts.VerifyAllSubstitutionMaps)
     verify();
@@ -87,7 +88,7 @@ ArrayRef<Type> SubstitutionMap::getInnermostReplacementTypes() const {
       getGenericSignature().getInnermostGenericParams().size());
 }
 
-GenericSignature SubstitutionMap::getGenericSignature() const {
+CanGenericSignature SubstitutionMap::getGenericSignature() const {
   return storage ? storage->getGenericSignature() : nullptr;
 }
 
@@ -127,12 +128,9 @@ bool SubstitutionMap::isCanonical() const {
   return true;
 }
 
-SubstitutionMap SubstitutionMap::getCanonical(bool canonicalizeSignature) const {
+SubstitutionMap SubstitutionMap::getCanonical() const {
   if (empty()) return *this;
 
-  auto sig = getGenericSignature();
-  if (canonicalizeSignature) sig = sig.getCanonicalSignature();
-
   SmallVector<Type, 4> replacementTypes;
   for (Type replacementType : getReplacementTypes()) {
     replacementTypes.push_back(replacementType->getCanonicalType());
@@ -143,7 +141,7 @@ SubstitutionMap SubstitutionMap::getCanonical(bool canonicalizeSignature) const
     conformances.push_back(conf.getCanonicalConformanceRef());
   }
 
-  return SubstitutionMap::get(sig,
+  return SubstitutionMap::get(getGenericSignature(),
                               ArrayRef<Type>(replacementTypes),
                               ArrayRef<ProtocolConformanceRef>(conformances));
 }

lib/AST/SubstitutionMapStorage.h

@@ -36,15 +36,15 @@ class SubstitutionMap::Storage final
   friend TrailingObjects;
 
   /// The generic signature for which we are performing substitutions.
-  GenericSignature genericSig;
+  CanGenericSignature genericSig;
 
   /// The number of conformance requirements, cached to avoid constantly
   /// recomputing it on conformance-buffer access.
   const unsigned numConformanceRequirements;
 
   Storage() = delete;
 
-  Storage(GenericSignature genericSig,
+  Storage(CanGenericSignature genericSig,
           ArrayRef<Type> replacementTypes,
           ArrayRef<ProtocolConformanceRef> conformances);
 
@@ -66,13 +66,13 @@ class SubstitutionMap::Storage final
 public:
   /// Form storage for the given generic signature and its replacement
   /// types and conformances.
-  static Storage *get(GenericSignature genericSig,
+  static Storage *get(CanGenericSignature genericSig,
                       ArrayRef<Type> replacementTypes,
                       ArrayRef<ProtocolConformanceRef> conformances);
 
   /// Retrieve the generic signature that describes the shape of this
   /// storage.
-  GenericSignature getGenericSignature() const { return genericSig; }
+  CanGenericSignature getGenericSignature() const { return genericSig; }
 
   /// Retrieve the array of replacement types, which line up with the
   /// generic parameters.
@@ -108,7 +108,7 @@ class SubstitutionMap::Storage final
 
   /// Profile the substitution map storage, for use with LLVM's FoldingSet.
   static void Profile(llvm::FoldingSetNodeID &id,
-                      GenericSignature genericSig,
+                      CanGenericSignature genericSig,
                       ArrayRef<Type> replacementTypes,
                       ArrayRef<ProtocolConformanceRef> conformances);
 };