AST: Refactor lookupQualified() to take a vector of NominalTypeDecls

Previously you could pass in a vector of TypeDecls and it handled
module and AnyObject lookup for you. The AnyObject case was never
used and the module was was only needed in one place, so clean
things up to make them more direct here.

Author: slavapestov

include/swift/AST/DeclContext.h

@@ -501,7 +501,7 @@ class alignas(1 << DeclContextAlignInBits) DeclContext {
   /// lookup.
   ///
   /// \returns true if anything was found.
-  bool lookupQualified(ArrayRef<TypeDecl *> types, DeclName member,
+  bool lookupQualified(ArrayRef<NominalTypeDecl *> types, DeclName member,
                        NLOptions options,
                        SmallVectorImpl<ValueDecl *> &decls) const;
 

lib/AST/NameLookup.cpp

@@ -603,7 +603,7 @@ SelfBoundsFromWhereClauseRequest::evaluate(Evaluator &evaluator,
 
 static void
 populateLookupDeclsFromContext(DeclContext *dc,
-                               SmallVectorImpl<TypeDecl *> &lookupDecls) {
+                               SmallVectorImpl<NominalTypeDecl *> &lookupDecls) {
   auto nominal = dc->getSelfNominalTypeDecl();
   if (!nominal)
     return;
@@ -831,7 +831,7 @@ UnqualifiedLookup::UnqualifiedLookup(DeclName Name, DeclContext *DC,
         if (!nominal) continue;
 
         // Dig out the type we're looking into.
-        SmallVector<TypeDecl *, 2> lookupDecls;
+        SmallVector<NominalTypeDecl *, 2> lookupDecls;
         populateLookupDeclsFromContext(dc, lookupDecls);
 
         NLOptions options = baseNLOptions;
@@ -897,7 +897,7 @@ UnqualifiedLookup::UnqualifiedLookup(DeclName Name, DeclContext *DC,
         DeclContext *MetaBaseDC = nullptr;
         GenericParamList *GenericParams = nullptr;
 
-        SmallVector<TypeDecl *, 2> lookupDecls;
+        SmallVector<NominalTypeDecl *, 2> lookupDecls;
 
         if (auto *PBI = dyn_cast<PatternBindingInitializer>(DC)) {
           auto *PBD = PBI->getBinding();
@@ -1940,15 +1940,10 @@ bool DeclContext::lookupQualified(Type type,
   SmallVector<NominalTypeDecl *, 4> nominalTypesToLookInto;
   extractDirectlyReferencedNominalTypes(type, nominalTypesToLookInto);
 
-  SmallVector<TypeDecl *, 4> typeDeclsToLookInto;
-  typeDeclsToLookInto.reserve(nominalTypesToLookInto.size());
-  for (auto nominal : nominalTypesToLookInto)
-    typeDeclsToLookInto.push_back(nominal);
-
-  return lookupQualified(typeDeclsToLookInto, member, options, decls);
+  return lookupQualified(nominalTypesToLookInto, member, options, decls);
 }
 
-bool DeclContext::lookupQualified(ArrayRef<TypeDecl *> typeDecls,
+bool DeclContext::lookupQualified(ArrayRef<NominalTypeDecl *> typeDecls,
                                   DeclName member,
                                   NLOptions options,
                                   SmallVectorImpl<ValueDecl *> &decls) const {
@@ -1977,38 +1972,17 @@ bool DeclContext::lookupQualified(ArrayRef<TypeDecl *> typeDecls,
     return true;
   };
 
-  // Look through the type declarations we were given, resolving them down
-  // to nominal type declarations, module declarations, and
-  ASTContext &ctx = getASTContext();
-  SmallVector<ModuleDecl *, 2> moduleDecls;
-  bool anyObject = false;
-  auto nominalTypeDecls =
-    resolveTypeDeclsToNominal(ctx.evaluator, ctx, typeDecls, moduleDecls,
-                              anyObject);
-
-  // If the only declaration we were given was AnyObject, this is AnyObject
-  // lookup.
-  if (anyObject && nominalTypeDecls.empty() && moduleDecls.empty())
-    return lookupAnyObject(member, options, decls);
-
   // Add all of the nominal types to the stack.
-  for (auto nominal : nominalTypeDecls) {
+  for (auto nominal : typeDecls) {
     addNominalType(nominal);
   }
 
-  // Search all of the modules.
-  for (auto module : moduleDecls) {
-    auto innerOptions = options;
-    innerOptions &= ~NL_RemoveOverridden;
-    innerOptions &= ~NL_RemoveNonVisible;
-    lookupQualified(module, member, innerOptions, decls);
-  }
-
   // Whether we only want to return complete object initializers.
   bool onlyCompleteObjectInits = false;
 
   // Visit all of the nominal types we know about, discovering any others
   // we need along the way.
+  auto &ctx = getASTContext();
   auto typeResolver = ctx.getLazyResolver();
   bool wantProtocolMembers = (options & NL_ProtocolMembers);
   while (!stack.empty()) {
@@ -2344,7 +2318,25 @@ directReferencesForQualifiedTypeLookup(Evaluator &evaluator,
     // Look into the base types.
     SmallVector<ValueDecl *, 4> members;
     auto options = NL_RemoveNonVisible | NL_OnlyTypes;
-    dc->lookupQualified(baseTypes, name, options, members);
+
+    // Look through the type declarations we were given, resolving them down
+    // to nominal type declarations, module declarations, and
+    SmallVector<ModuleDecl *, 2> moduleDecls;
+    bool anyObject = false;
+    auto nominalTypeDecls =
+      resolveTypeDeclsToNominal(ctx.evaluator, ctx, baseTypes, moduleDecls,
+                                anyObject);
+
+    dc->lookupQualified(nominalTypeDecls, name, options, members);
+
+    // Search all of the modules.
+    for (auto module : moduleDecls) {
+      auto innerOptions = options;
+      innerOptions &= ~NL_RemoveOverridden;
+      innerOptions &= ~NL_RemoveNonVisible;
+      dc->lookupQualified(module, name, innerOptions, members);
+    }
+
     addResults(members);
   }
 

lib/Sema/TypeCheckDeclOverride.cpp

@@ -549,7 +549,7 @@ namespace {
 
     /// The set of declarations in which we'll look for overridden
     /// methods.
-    DirectlyReferencedTypeDecls superContexts;
+    SmallVector<NominalTypeDecl *, 2> superContexts;
 
     /// Cached member lookup results.
     SmallVector<ValueDecl *, 4> members;