Handle module selectors in UDRE lookups

Author: beccadax

lib/Sema/TypeCheckNameLookup.cpp

@@ -60,6 +60,7 @@ namespace {
   class LookupResultBuilder {
     LookupResult &Result;
     DeclContext *DC;
+    Identifier ModuleSelector;
     NameLookupOptions Options;
 
     /// The vector of found declarations.
@@ -72,8 +73,9 @@ namespace {
 
   public:
     LookupResultBuilder(LookupResult &result, DeclContext *dc,
-                        NameLookupOptions options)
-      : Result(result), DC(dc), Options(options) {
+                        Identifier moduleSelector, NameLookupOptions options)
+      : Result(result), DC(dc), ModuleSelector(moduleSelector), Options(options)
+    {
       if (dc->getASTContext().isAccessControlDisabled())
         Options |= NameLookupFlags::IgnoreAccessControl;
     }
@@ -83,6 +85,11 @@ namespace {
       removeOverriddenDecls(FoundDecls);
       removeOverriddenDecls(FoundOuterDecls);
 
+      // Remove any declarations excluded by the module selector from the
+      // found-declarations set.
+      removeOutOfModuleDecls(FoundDecls, ModuleSelector, DC);
+      removeOutOfModuleDecls(FoundOuterDecls, ModuleSelector, DC);
+
       // Remove any shadowed declarations from the found-declarations set.
       removeShadowedDecls(FoundDecls, DC);
       removeShadowedDecls(FoundOuterDecls, DC);
@@ -290,7 +297,7 @@ LookupResult TypeChecker::lookupUnqualified(DeclContext *dc, DeclNameRef name,
                                   UnqualifiedLookupRequest{descriptor}, {});
 
   LookupResult result;
-  LookupResultBuilder builder(result, dc, options);
+  LookupResultBuilder builder(result, dc, name.getModuleSelector(), options);
   for (auto idx : indices(lookup.allResults())) {
     const auto &found = lookup[idx];
     // Determine which type we looked through to find this result.
@@ -381,7 +388,7 @@ LookupResult TypeChecker::lookupMember(DeclContext *dc,
   // Make sure we've resolved implicit members, if we need them.
   namelookup::installSemanticMembersIfNeeded(type, name);
 
-  LookupResultBuilder builder(result, dc, options);
+  LookupResultBuilder builder(result, dc, name.getModuleSelector(), options);
   SmallVector<ValueDecl *, 4> lookupResults;
   dc->lookupQualified(type, name, loc, subOptions, lookupResults);
 

test/NameLookup/module_selector.swift

@@ -107,6 +107,8 @@ extension B: @retroactive main::Equatable {
       // expected-error@-2 {{cannot infer contextual base in reference to member 'main::min'}}
 
       self = B.main::init(value: .min)
+      // FIXME improve: expected-error@-1 {{'B' cannot be constructed because it has no accessible initializers}}
+      // expected-error@-2 {{cannot infer contextual base in reference to member 'min'}}
     }
 
     self.main::myNegate()
@@ -140,6 +142,8 @@ extension C: @retroactive ModuleSelectorTestingKit::Equatable {
   @_dynamicReplacement(for: ModuleSelectorTestingKit::negate())
 
   mutating func myNegate() {
+  // FIXME improve: expected-note@-1 {{did you mean 'myNegate'?}}
+
     let fn: (ModuleSelectorTestingKit::Int, ModuleSelectorTestingKit::Int) -> ModuleSelectorTestingKit::Int =
     // FIXME improve: expected-error@-1 3{{cannot find type 'ModuleSelectorTestingKit::Int' in scope}}
       (ModuleSelectorTestingKit::+)
@@ -157,11 +161,13 @@ extension C: @retroactive ModuleSelectorTestingKit::Equatable {
     }
     else {
       self = ModuleSelectorTestingKit::C(value: .ModuleSelectorTestingKit::min)
+      // FIXME improve: expected-error@-1 {{type 'Int' has no member 'ModuleSelectorTestingKit::min'}}
 
       self = C.ModuleSelectorTestingKit::init(value: .min)
     }
 
     self.ModuleSelectorTestingKit::myNegate()
+    // FIXME improve: expected-error@-1 {{value of type 'C' has no member 'ModuleSelectorTestingKit::myNegate'}}
 
     ModuleSelectorTestingKit::fatalError()
     // FIXME improve: expected-error@-1 {{cannot find 'ModuleSelectorTestingKit::fatalError' in scope}}
@@ -212,9 +218,12 @@ extension D: @retroactive Swift::Equatable {
       // expected-error@-2 {{cannot infer contextual base in reference to member 'Swift::min'}}
 
       self = D.Swift::init(value: .min)
+      // FIXME improve: expected-error@-1 {{'D' cannot be constructed because it has no accessible initializers}}
+      // expected-error@-2 {{cannot infer contextual base in reference to member 'min'}}
     }
 
     self.Swift::myNegate()
+    // FIXME improve: expected-error@-1 {{value of type 'D' has no member 'Swift::myNegate'}}
 
     Swift::fatalError()
   }
@@ -293,6 +302,8 @@ func badModuleNames() {
   // expected-error@-1 {{cannot find 'NonexistentModule::print' in scope}}
 
   _ = "foo".NonexistentModule::count
+  // FIXME improve: expected-error@-1 {{value of type 'String' has no member 'NonexistentModule::count'}}
+  // FIXME: expected-EVENTUALLY-note@-2 {{did you mean module 'Swift'?}} {{13-30=Swift}}
 
   let x: NonexistentModule::MyType = NonexistentModule::MyType()
   // expected-error@-1 {{cannot find type 'NonexistentModule::MyType' in scope}}