Merge pull request #4758 from slavapestov/small-generics-cleanups

Small generics cleanups

Author: slavapestov

include/swift/AST/ArchetypeBuilder.h

@@ -346,10 +346,6 @@ class ArchetypeBuilder {
                                   GenericEnvironment *genericEnv,
                                   Type type);
 
-  using SameTypeRequirement
-    = std::pair<PotentialArchetype *,
-                PointerUnion<Type, PotentialArchetype*>>;
-
   /// \brief Dump all of the requirements, both specified and inferred.
   LLVM_ATTRIBUTE_DEPRECATED(
       void dump(),

include/swift/AST/GenericSignature.h

@@ -35,20 +35,27 @@ class SubstitutionMap;
 /// signature and their dependent members.
 class GenericSignatureWitnessIterator {
   ArrayRef<Requirement> p;
-  
+
+  void checkValid() const {
+    assert(!p.empty() &&
+           p.front().getKind() == RequirementKind::WitnessMarker);
+  }
+
+  bool shouldSkip() const {
+    return (!p.empty() &&
+            p.front().getKind() != RequirementKind::WitnessMarker);
+  }
+
 public:
   GenericSignatureWitnessIterator() = default;
-  GenericSignatureWitnessIterator(ArrayRef<Requirement> p)
-    : p(p)
-  {
-    assert(p.empty() || p.front().getKind() == RequirementKind::WitnessMarker);
+  GenericSignatureWitnessIterator(ArrayRef<Requirement> requirements)
+      : p(requirements) {
+    while (shouldSkip()) { p = p.slice(1); }
   }
 
   GenericSignatureWitnessIterator &operator++() {
-    do {
-      p = p.slice(1);
-    } while (!p.empty()
-             && p.front().getKind() != RequirementKind::WitnessMarker);
+    checkValid();
+    do { p = p.slice(1); } while (shouldSkip());
     return *this;
   }
 
@@ -59,12 +66,12 @@ class GenericSignatureWitnessIterator {
   }
 
   Type operator*() const {
-    assert(p.front().getKind() == RequirementKind::WitnessMarker);
+    checkValid();
     return p.front().getFirstType();
   }
 
   Type operator->() const {
-    assert(p.front().getKind() == RequirementKind::WitnessMarker);
+    checkValid();
     return p.front().getFirstType();
   }
 
@@ -162,7 +169,14 @@ class GenericSignature final : public llvm::FoldingSetNode,
     return const_cast<GenericSignature *>(this)->getRequirementsBuffer();
   }
 
-  // Only allow allocation by doing a placement new.
+  /// Check if the generic signature makes all generic parameters
+  /// concrete.
+  bool areAllParamsConcrete() const {
+    auto iter = getAllDependentTypes();
+    return iter.begin() == iter.end();
+  }
+
+  /// Only allow allocation by doing a placement new.
   void *operator new(size_t Bytes, void *Mem) {
     assert(Mem);
     return Mem;

include/swift/AST/Substitution.h

@@ -57,15 +57,6 @@ class Substitution {
 
   /// Apply a substitution to this substitution's replacement type and
   /// conformances.
-  ///
-  /// Our replacement type must be written in terms of the context
-  /// archetypes of 'env', which in turn must be derived from the
-  /// generic requirements of 'sig'.
-  Substitution subst(ModuleDecl *module,
-                     GenericSignature *sig,
-                     GenericEnvironment *env,
-                     ArrayRef<Substitution> subs) const;
-
   Substitution subst(ModuleDecl *module,
                      const SubstitutionMap &subMap) const;
 

include/swift/AST/Types.h

@@ -3757,17 +3757,6 @@ class ArchetypeType final : public SubstitutableType,
     return AssocTypeOrProto.dyn_cast<ProtocolDecl *>();
   }
 
-  /// True if this is the 'Self' parameter of a protocol or an associated type
-  /// of 'Self'.
-  bool isSelfDerived() {
-    ArchetypeType *t = getPrimary();
-
-    if (t && t->getSelfProtocol())
-      return true;
-
-    return false;
-  }
-
   /// getConformsTo - Retrieve the set of protocols to which this substitutable
   /// type shall conform.
   ArrayRef<ProtocolDecl *> getConformsTo() const { return ConformsTo; }

include/swift/SIL/TypeSubstCloner.h

@@ -18,6 +18,7 @@
 #ifndef SWIFT_SIL_TYPESUBSTCLONER_H
 #define SWIFT_SIL_TYPESUBSTCLONER_H
 
+#include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/Type.h"
 #include "swift/SIL/SILCloner.h"
 #include "swift/SIL/DynamicCasts.h"
@@ -38,6 +39,13 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
     llvm_unreachable("Clients need to explicitly call a base class impl!");
   }
 
+  void computeSubsMap() {
+    if (auto *env = Original.getGenericEnvironment()) {
+      auto sig = Original.getLoweredFunctionType()->getGenericSignature();
+      SubsMap = env->getSubstitutionMap(SwiftMod, sig, ApplySubs);
+    }
+  }
+
 public:
   using SILClonerWithScopes<ImplClass>::asImpl;
   using SILClonerWithScopes<ImplClass>::getBuilder;
@@ -55,28 +63,28 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
 
   TypeSubstCloner(SILFunction &To,
                   SILFunction &From,
-                  const SubstitutionMap &ContextSubs,
                   ArrayRef<Substitution> ApplySubs,
                   SILOpenedArchetypesTracker &OpenedArchetypesTracker,
                   bool Inlining = false)
     : SILClonerWithScopes<ImplClass>(To, OpenedArchetypesTracker, Inlining),
       SwiftMod(From.getModule().getSwiftModule()),
-      SubsMap(ContextSubs),
       Original(From),
       ApplySubs(ApplySubs),
-      Inlining(Inlining) { }
+      Inlining(Inlining) {
+    computeSubsMap();
+  }
 
   TypeSubstCloner(SILFunction &To,
                   SILFunction &From,
-                  const SubstitutionMap &ContextSubs,
                   ArrayRef<Substitution> ApplySubs,
                   bool Inlining = false)
     : SILClonerWithScopes<ImplClass>(To, Inlining),
       SwiftMod(From.getModule().getSwiftModule()),
-      SubsMap(ContextSubs),
       Original(From),
       ApplySubs(ApplySubs),
-      Inlining(Inlining) { }
+      Inlining(Inlining) {
+    computeSubsMap();
+  }
 
 
 protected:
@@ -90,11 +98,8 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
   }
 
   Substitution remapSubstitution(Substitution sub) {
-    if (!ApplySubs.empty()) {
-      auto sig = Original.getLoweredFunctionType()->getGenericSignature();
-      auto *env = Original.getGenericEnvironment();
-      sub = sub.subst(SwiftMod, sig, env, ApplySubs);
-    }
+    sub = sub.subst(SwiftMod, SubsMap);
+
     // Remap opened archetypes into the cloned context.
     return Substitution(getASTTypeInClonedContext(sub.getReplacement()
                                                     ->getCanonicalType()),
@@ -208,12 +213,7 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
   void visitWitnessMethodInst(WitnessMethodInst *Inst) {
     // Specialize the Self substitution of the witness_method.
     auto sub = Inst->getSelfSubstitution();
-    if (!ApplySubs.empty()) {
-      auto sig = Original.getLoweredFunctionType()->getGenericSignature();
-      auto *env = Original.getGenericEnvironment();
-      sub = sub.subst(Inst->getModule().getSwiftModule(),
-                      sig, env, ApplySubs);
-    }
+    sub = sub.subst(Inst->getModule().getSwiftModule(), SubsMap);
 
     assert(sub.getConformances().size() == 1 &&
            "didn't get conformance from substitution?!");
@@ -289,7 +289,7 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
   /// The Swift module that the cloned function belongs to.
   Module *SwiftMod;
   /// The substitutions list for the specialization.
-  const SubstitutionMap &SubsMap;
+  SubstitutionMap SubsMap;
   /// The original function to specialize.
   SILFunction &Original;
   /// The substitutions used at the call site.

include/swift/SILOptimizer/Utils/GenericCloner.h

@@ -41,11 +41,10 @@ class GenericCloner : public TypeSubstCloner<GenericCloner> {
   GenericCloner(SILFunction *F,
                 IsFragile_t Fragile,
                 const ReabstractionInfo &ReInfo,
-                SubstitutionMap &ContextSubs,
                 ArrayRef<Substitution> ParamSubs,
                 StringRef NewName,
                 CloneCollector::CallbackType Callback)
-  : TypeSubstCloner(*initCloned(F, Fragile, ReInfo, NewName), *F, ContextSubs,
+  : TypeSubstCloner(*initCloned(F, Fragile, ReInfo, NewName), *F,
                     ParamSubs), ReInfo(ReInfo), Callback(Callback) {
     assert(F->getDebugScope()->Parent != getCloned()->getDebugScope()->Parent);
   }
@@ -56,12 +55,11 @@ class GenericCloner : public TypeSubstCloner<GenericCloner> {
   cloneFunction(SILFunction *F,
                 IsFragile_t Fragile,
                 const ReabstractionInfo &ReInfo,
-                SubstitutionMap &ContextSubs,
                 ArrayRef<Substitution> ParamSubs,
                 StringRef NewName,
                 CloneCollector::CallbackType Callback =nullptr) {
     // Clone and specialize the function.
-    GenericCloner SC(F, Fragile, ReInfo, ContextSubs, ParamSubs,
+    GenericCloner SC(F, Fragile, ReInfo, ParamSubs,
                      NewName, Callback);
     SC.populateCloned();
     SC.cleanUp(SC.getCloned());

include/swift/SILOptimizer/Utils/SILInliner.h

@@ -46,10 +46,10 @@ class SILInliner : public TypeSubstCloner<SILInliner> {
   };
 
   SILInliner(SILFunction &To, SILFunction &From, InlineKind IKind,
-             SubstitutionMap &ContextSubs, ArrayRef<Substitution> ApplySubs,
+             ArrayRef<Substitution> ApplySubs,
              SILOpenedArchetypesTracker &OpenedArchetypesTracker,
              CloneCollector::CallbackType Callback = nullptr)
-      : TypeSubstCloner<SILInliner>(To, From, ContextSubs, ApplySubs,
+      : TypeSubstCloner<SILInliner>(To, From, ApplySubs,
                                     OpenedArchetypesTracker, true),
         IKind(IKind), CalleeEntryBB(nullptr), CallSiteScope(nullptr),
         Callback(Callback) {

lib/AST/ASTScope.cpp

@@ -1439,6 +1439,13 @@ SourceRange ASTScope::getSourceRangeImpl() const {
     return cast<NominalTypeDecl>(iterableDeclContext)->getBraces();
 
   case ASTScopeKind::GenericParams:
+    // A protocol's generic parameter list is not written in source, and
+    // is visible from the start of the body.
+    if (auto *protoDecl = dyn_cast<ProtocolDecl>(genericParams.decl)) {
+      return SourceRange(protoDecl->getBraces().Start,
+                         protoDecl->getEndLoc());
+    }
+
     // Explicitly-written generic parameters are in scope following their
     // definition.
     return SourceRange(genericParams.params->getParams()[genericParams.index]

lib/AST/Decl.cpp

@@ -2185,7 +2185,7 @@ GenericTypeDecl::GenericTypeDecl(DeclKind K, DeclContext *DC,
 
 
 void GenericTypeDecl::setGenericParams(GenericParamList *params) {
-  // Set the specified generic parameters onto this type alias, setting
+  // Set the specified generic parameters onto this type declaration, setting
   // the parameters' context along the way.
   GenericParams = params;
   if (params)

lib/AST/Substitution.cpp

@@ -42,15 +42,6 @@ Substitution::Substitution(Type Replacement,
          && "cannot substitute with a non-materializable type");
 }
 
-Substitution Substitution::subst(Module *module,
-                                 GenericSignature *sig,
-                                 GenericEnvironment *env,
-                                 ArrayRef<Substitution> subs) const {
-  assert(sig && env);
-  auto subMap = env->getSubstitutionMap(module, sig, subs);
-  return subst(module, subMap);
-}
-
 Substitution Substitution::subst(Module *module,
                                  const SubstitutionMap &subMap) const {
   // Substitute the replacement.

lib/AST/Type.cpp

@@ -2816,19 +2816,10 @@ static Type getMemberForBaseType(ConformanceSource conformances,
     if (archetypeParent->hasNestedType(name))
       return archetypeParent->getNestedTypeValue(name);
 
-    if (auto parent = archetypeParent->getParent()) {
-      // If the archetype doesn't have the requested type and the parent is not
-      // self derived, error out
-      return parent->isSelfDerived() ? parent->getNestedTypeValue(name)
-                                     : ErrorType::get(substBase->getASTContext());
-    }
-
     // If looking for an associated type and the archetype is constrained to a
     // class, continue to the default associated type lookup
-    if (!assocType || !archetypeParent->getSuperclass()) {
-      // else just error out
+    if (!assocType || !archetypeParent->getSuperclass())
       return ErrorType::get(substBase->getASTContext());
-    }
   }
 
   // If the parent is a type variable, retrieve its member type