[NFC] Additional DeclNameRef auditing

Author: beccadax

lib/Sema/CSGen.cpp

@@ -3174,8 +3174,8 @@ namespace {
                                                 TVO_CanBindToNoEscape);
           componentTypeVars.push_back(memberTy);
           auto lookupName = kind == KeyPathExpr::Component::Kind::UnresolvedProperty
-            ? DeclNameRef(component.getUnresolvedDeclName()) // FIXME: type change needed
-            : component.getDeclRef().getDecl()->createNameRef();
+            ? component.getUnresolvedDeclName()
+            : component.getDeclRef().getDecl()->createNameRef(/*modSel=*/true);
 
           auto refKind = lookupName.isSimpleName()
             ? FunctionRefKind::Unapplied
@@ -4195,9 +4195,13 @@ swift::resolveValueMember(DeclContext &DC, Type BaseTy, DeclName Name) {
   ResolvedMemberResult Result;
   ConstraintSystem CS(&DC, None);
 
+  // OK: By contract, `Name` should be derived from an existing Decl, not a
+  // name written by the user in source code. So when used as intended, we won't
+  // be dropping a module selector here.
+  DeclNameRef NameRef(Name);
   // Look up all members of BaseTy with the given Name.
   MemberLookupResult LookupResult = CS.performMemberLookup(
-      ConstraintKind::ValueMember, DeclNameRef(Name), BaseTy,
+      ConstraintKind::ValueMember, NameRef, BaseTy,
       FunctionRefKind::SingleApply, CS.getConstraintLocator({}), false);
 
   // Keep track of all the unviable members.

lib/Sema/CSSimplify.cpp

@@ -6092,6 +6092,9 @@ ConstraintSystem::simplifyConstructionConstraint(
   // variable T. T2 is the result type provided via the construction
   // constraint itself.
   addValueMemberConstraint(MetatypeType::get(valueType, getASTContext()),
+                           // OK: simplifyConstructionConstraint() is only used
+                           // for `T(...)` init calls, not `T.init(...)` calls,
+                           // so there's no module selector on `init`.
                            DeclNameRef::createConstructor(),
                            memberType,
                            useDC, functionRefKind,
@@ -11165,7 +11168,9 @@ ConstraintSystem::simplifyRestrictedConstraintImpl(
     auto *memberTy = createTypeVariable(memberLoc, TVO_CanBindToNoEscape);
 
     addValueMemberConstraint(MetatypeType::get(type2, getASTContext()),
-                             DeclNameRef(DeclBaseName::createConstructor()),
+                             // OK: Implicit conversion, no module selector to
+                             // drop here.
+                             DeclNameRef::createConstructor(),
                              memberTy, DC, FunctionRefKind::DoubleApply,
                              /*outerAlternatives=*/{}, memberLoc);
 

lib/Sema/TypeCheckAttr.cpp

@@ -1977,6 +1977,8 @@ SynthesizeMainFunctionRequest::evaluate(Evaluator &evaluator,
   // mainType.main() from the entry point, and that would require fully
   // type-checking the call to mainType.main().
 
+  // FIXME: resolveValueMember() is intended for IDEs--we should use something
+  // else.
   auto resolution = resolveValueMember(
       *declContext, nominal->getInterfaceType(), context.Id_main);
 

test/NameLookup/module_selector.swift

@@ -9,6 +9,8 @@
 // * Whether we handle access paths correctly
 // * Interaction with ClangImporter
 // * Cross-import overlays
+// * Key paths
+// * Key path dynamic member lookup
 //
 // It also might not cover all combinations of name lookup paths and inputs.