Improve diagnostics for types with incorrect module selectors

beccadax · beccadax · commit 51b335f117c3 · 2025-05-10T01:58:19.000-07:00
diff --git a/include/swift/AST/Decl.h b/include/swift/AST/Decl.h
@@ -2993,11 +2993,10 @@ class ValueDecl : public Decl {
     return Name.getBaseIdentifier();
   }
 
-  /// Generates a DeclNameRef referring to this declaration with as much
-  /// specificity as possible.
-  DeclNameRef createNameRef() const {
-    return DeclNameRef(Name);
-  }
+  /// Generates a DeclNameRef referring to this declaration.
+  ///
+  /// \param moduleSelector If true, the name ref includes the module name.
+  DeclNameRef createNameRef(bool moduleSelector = false) const;
 
   /// Retrieve the C declaration name that names this function, or empty
   /// string if it has none.
diff --git a/include/swift/AST/DiagnosticsSema.def b/include/swift/AST/DiagnosticsSema.def
@@ -1159,6 +1159,10 @@ ERROR(cannot_find_type_in_cast_expression,none,
       "type-casting operator expects a type on its right-hand side (got: %kind0)", (const ValueDecl *))
 ERROR(cannot_find_type_in_scope_did_you_mean,none,
       "cannot find type %0 in scope; did you mean to use '%1'?", (DeclNameRef, StringRef))
+ERROR(type_not_in_module,none,
+      "type %0 is not imported through module %1", (DeclName, Identifier))
+NOTE(note_change_module_selector,none,
+     "did you mean module %0?", (Identifier))
 NOTE(note_typo_candidate_implicit_member,none,
      "did you mean the implicitly-synthesized %kindbase0?", (const ValueDecl *))
 NOTE(note_remapped_type,none,
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
@@ -2825,6 +2825,14 @@ SourceRange TopLevelCodeDecl::getSourceRange() const {
   return Body? Body->getSourceRange() : SourceRange();
 }
 
+DeclNameRef ValueDecl::createNameRef(bool moduleSelector) const {
+  if (moduleSelector)
+    return DeclNameRef(getASTContext(), getModuleContext()->getName(),
+                       getName());
+
+  return DeclNameRef(getName());
+}
+
 static bool isPolymorphic(const AbstractStorageDecl *storage) {
   if (storage->shouldUseObjCDispatch())
     return true;
diff --git a/lib/Sema/TypeCheckType.cpp b/lib/Sema/TypeCheckType.cpp
@@ -1493,6 +1493,33 @@ static Type diagnoseUnknownType(const TypeResolution &resolution,
       return ErrorType::get(ctx);
     }
 
+    // Is there an incorrect module selector?
+    if (repr->getNameRef().hasModuleSelector()) {
+      auto anyModuleName = DeclNameRef(repr->getNameRef().getFullName());
+      auto anyModuleResults =
+      TypeChecker::lookupUnqualifiedType(dc, anyModuleName,
+                                         repr->getLoc(), lookupOptions);
+      if (!anyModuleResults.empty()) {
+        diags.diagnose(repr->getNameLoc(), diag::type_not_in_module,
+                       repr->getNameRef().getFullName(),
+                       repr->getNameRef().getModuleSelector());
+
+        SourceLoc moduleSelectorLoc = repr->getNameLoc().getModuleSelectorLoc();
+
+        for (auto result : anyModuleResults) {
+          TypeDecl * decl = static_cast<TypeDecl*>(result.getValueDecl());
+          Identifier moduleName = decl->getModuleContext()->getName();
+
+          diags.diagnose(moduleSelectorLoc, diag::note_change_module_selector,
+                         moduleName)
+              .fixItReplace(moduleSelectorLoc, moduleName.str());
+        }
+
+        // FIXME: Can we recover by assuming the first/best result is correct?
+        return ErrorType::get(ctx);
+      }
+    }
+
     // Try ignoring access control.
     NameLookupOptions relookupOptions = lookupOptions;
     relookupOptions |= NameLookupFlags::IgnoreAccessControl;
@@ -1584,6 +1611,32 @@ static Type diagnoseUnknownType(const TypeResolution &resolution,
     return ErrorType::get(ctx);
   }
 
+  // Is there an incorrect module selector?
+  if (repr->getNameRef().hasModuleSelector()) {
+    auto anyModuleName = DeclNameRef(repr->getNameRef().getFullName());
+    auto anyModuleResults = TypeChecker::lookupMemberType(
+        dc, parentType, anyModuleName, repr->getLoc(), lookupOptions);
+    if (anyModuleResults) {
+      diags.diagnose(repr->getNameLoc(), diag::type_not_in_module,
+                     repr->getNameRef().getFullName(),
+                     repr->getNameRef().getModuleSelector());
+
+      SourceLoc moduleSelectorLoc = repr->getNameLoc().getModuleSelectorLoc();
+
+      for (auto result : anyModuleResults) {
+        TypeDecl * decl = result.Member;
+        Identifier moduleName = decl->getModuleContext()->getName();
+
+        diags.diagnose(moduleSelectorLoc, diag::note_change_module_selector,
+                       moduleName)
+            .fixItReplace(moduleSelectorLoc, moduleName.str());
+      }
+
+      // FIXME: Can we recover by assuming the first/best result is correct?
+      return ErrorType::get(ctx);
+    }
+  }
+
   // Try ignoring access control.
   NameLookupOptions relookupOptions = lookupOptions;
   relookupOptions |= NameLookupFlags::IgnoreAccessControl;
diff --git a/test/NameLookup/module_selector.swift b/test/NameLookup/module_selector.swift
@@ -15,36 +15,59 @@ let magnitude: Never = fatalError()
 // Test resolution of main:: using `B`
 
 extension main::B {}
-// FIXME improve: expected-error@-1 {{use of undeclared type 'main::B'}}
+// expected-error@-1 {{type 'B' is not imported through module 'main'}}
+// expected-note@-2 {{did you mean module 'ModuleSelectorTestingKit'?}} {{11-15=ModuleSelectorTestingKit}}
 
 extension B: main::Equatable {
+  // expected-error@-1 {{type 'Equatable' is not imported through module 'main'}}
+  // expected-note@-2 {{did you mean module 'Swift'?}} {{14-18=Swift}}
+
   @_implements(main::Equatable, main::==(_:_:))
   // expected-error@-1 {{name cannot be qualified with module selector here}} {{33-39=}}
-  public static func equals(_: main::B, _: main::B) -> main::Bool { main::fatalError() }
-  
+  // expected-error@-2 {{type 'Equatable' is not imported through module 'main'}}
+  // expected-note@-3 {{did you mean module 'Swift'?}} {{16-20=Swift}}
+  public static func equals(_: main::B, _: main::B) -> main::Bool {
+  // expected-error@-1 2{{type 'B' is not imported through module 'main'}}
+  // expected-note@-2 {{did you mean module 'ModuleSelectorTestingKit'?}} {{32-36=ModuleSelectorTestingKit}}
+  // expected-note@-3 {{did you mean module 'ModuleSelectorTestingKit'?}} {{44-48=ModuleSelectorTestingKit}}
+  // expected-error@-4 {{type 'Bool' is not imported through module 'main'}}
+  // expected-note@-5 {{did you mean module 'Swift'?}} {{56-60=Swift}}
+    main::fatalError()
+    // expected-EVENTUALLY-error@-1 {{type 'fatalError' is not imported through module 'main'}}
+    // expected-EVENTUALLY-note@-2 {{did you mean module 'Swift'?}} {{4-8=Swift}}
+  }
+
   // FIXME: Add tests with autodiff @_differentiable(jvp:vjp:) and
   // @_derivative(of:)
   
   @_dynamicReplacement(for: main::negate())
   // FIXME improve: expected-error@-1 {{replaced function 'main::negate()' could not be found}}
   mutating func myNegate() {
     let fn: (main::Int, main::Int) -> main::Int =
-    // FIXME:
+    // expected-error@-1 3{{type 'Int' is not imported through module 'main'}}
+    // expected-note@-2 {{did you mean module 'Swift'?}} {{14-18=Swift}}
+    // expected-note@-3 {{did you mean module 'Swift'?}} {{25-29=Swift}}
+    // expected-note@-4 {{did you mean module 'Swift'?}} {{39-43=Swift}}
       (main::+)
-      // expected-error@-1 {{cannot convert value of type '()' to specified type '(Int, Int) -> Int'}}
+      // FIXME: it'd be nice to handle module selectors on operators.
       // expected-error@-2 {{expected expression}}
       // expected-error@-3 {{expected expression after operator}}
 
     let magnitude: Int.main::Magnitude = main::magnitude
-    // expected-EVENTUALLY-error@-1 {{can't find 'Int'}}
-    // FIXME improve: expected-error@-2 {{type alias 'Magnitude' is not a member type of 'Int'}}
-    // FIXME: expected-error@-3 {{variable used within its own initial value}}
+    // expected-error@-1 {{type 'Magnitude' is not imported through module 'main'}}
+    // expected-note@-2 {{did you mean module 'Swift'?}} {{24-28=Swift}}
+    // FIXME incorrect: expected-error@-3 {{variable used within its own initial value}}
+
     if main::Bool.main::random() {
+    // FIXME improve: expected-error@-1 {{use of unresolved identifier 'main::Bool'}}
+
       main::negate()
-      // FIXME improve: expected-error@-1 {{use of unresolved identifier 'main::negate'}}
+      // FIXME improve, suggest adding 'self.': expected-error@-1 {{use of unresolved identifier 'main::negate'}}
     }
     else {
       self = main::B(value: .main::min)
+      // FIXME improve: expected-error@-1 {{use of unresolved identifier 'main::B'}}
+      // expected-error@-2 {{cannot infer contextual base in reference to member 'main::min'}}
     }
     
     self.main::myNegate()
@@ -58,30 +81,45 @@ extension B: main::Equatable {
 extension C {}
 
 extension ModuleSelectorTestingKit::C: ModuleSelectorTestingKit::Equatable {
-// FIXME improve: expected-error@-1 {{use of undeclared type 'ModuleSelectorTestingKit::Equatable'}}
+// expected-error@-1 {{type 'Equatable' is not imported through module 'ModuleSelectorTestingKit'}}
+// expected-note@-2 {{did you mean module 'Swift'?}} {{39-62=Swift}}
+
   @_implements(ModuleSelectorTestingKit::Equatable, ModuleSelectorTestingKit::==(_:_:))
-  // FIXME improve: expected-error@-1 {{use of undeclared type 'ModuleSelectorTestingKit::Equatable'}}
-  // expected-error@-2 {{name cannot be qualified with module selector here}} {{52-77=}}
-  public static func equals(_: ModuleSelectorTestingKit::C, _: ModuleSelectorTestingKit::C) -> ModuleSelectorTestingKit::Bool { ModuleSelectorTestingKit::fatalError() }
-  // FIXME improve: expected-error@-1 {{use of undeclared type 'ModuleSelectorTestingKit::Bool'}}
+  // expected-error@-1 {{name cannot be qualified with module selector here}} {{52-77=}}
+  // expected-error@-2 {{type 'Equatable' is not imported through module 'ModuleSelectorTestingKit'}}
+  // expected-note@-3 {{did you mean module 'Swift'?}} {{16-39=Swift}}
+
+  public static func equals(_: ModuleSelectorTestingKit::C, _: ModuleSelectorTestingKit::C) -> ModuleSelectorTestingKit::Bool {
+  // expected-error@-1 {{type 'Bool' is not imported through module 'ModuleSelectorTestingKit'}}
+  // expected-note@-2 {{did you mean module 'Swift'?}} {{94-117=Swift}}
+    ModuleSelectorTestingKit::fatalError()
+    // expected-EVENTUALLY-error@-1 {{type 'fatalError' is not imported through module 'main'}}
+    // expected-EVENTUALLY-note@-2 {{did you mean module 'Swift'?}} {{4-8=Swift}}
+  }
 
   // FIXME: Add tests with autodiff @_differentiable(jvp:vjp:) and
   // @_derivative(of:)
   
   @_dynamicReplacement(for: ModuleSelectorTestingKit::negate())
   mutating func myNegate() {
     let fn: (ModuleSelectorTestingKit::Int, ModuleSelectorTestingKit::Int) -> ModuleSelectorTestingKit::Int =
-    // FIXME improve: expected-error@-1 3{{use of undeclared type 'ModuleSelectorTestingKit::Int'}}
-    // FIXME:
+    // expected-error@-1 3{{type 'Int' is not imported through module 'ModuleSelectorTestingKit'}}
+    // expected-note@-2 {{did you mean module 'Swift'?}} {{14-37=Swift}}
+    // expected-note@-3 {{did you mean module 'Swift'?}} {{44-67=Swift}}
+    // expected-note@-4 {{did you mean module 'Swift'?}} {{77-100=Swift}}
       (ModuleSelectorTestingKit::+)
-      // expected-error@-1 {{expected expression}}
-      // expected-error@-2 {{expected expression after operator}}
+      // FIXME: it'd be nice to handle module selectors on operators.
+      // expected-error@-2 {{expected expression}}
+      // expected-error@-3 {{expected expression after operator}}
+
     let magnitude: Int.ModuleSelectorTestingKit::Magnitude = ModuleSelectorTestingKit::magnitude
-    // expected-EVENTUALLY-error@-1 {{something about not finding 'magnitude' because we didn't look in self}}
-    // FIXME improve: expected-error@-2 {{type alias 'Magnitude' is not a member type of 'Int'}}
-    // FIXME: expected-error@-3 {{variable used within its own initial value}}
+    // expected-error@-1 {{type 'Magnitude' is not imported through module 'ModuleSelectorTestingKit'}}
+    // expected-note@-2 {{did you mean module 'Swift'?}} {{24-47=Swift}}
+    // FIXME incorrect: expected-error@-3 {{variable used within its own initial value}}
+
     if ModuleSelectorTestingKit::Bool.ModuleSelectorTestingKit::random() {
     // FIXME improve: expected-error@-1 {{use of unresolved identifier 'ModuleSelectorTestingKit::Bool'}}
+
       ModuleSelectorTestingKit::negate()
       // FIXME improve, suggest adding 'self.': expected-error@-1 {{use of unresolved identifier 'ModuleSelectorTestingKit::negate'}}
     }
@@ -100,13 +138,22 @@ extension ModuleSelectorTestingKit::C: ModuleSelectorTestingKit::Equatable {
 // FIXME: Many more of these should fail once the feature is actually implemented.
 
 extension Swift::D {}
-// FIXME improve: expected-error@-1 {{use of undeclared type 'Swift::D'}}
+// expected-error@-1 {{type 'D' is not imported through module 'Swift'}}
+// expected-note@-2 {{did you mean module 'ModuleSelectorTestingKit'?}} {{11-16=ModuleSelectorTestingKit}}
 
 extension D: @retroactive Swift::Equatable {
+// Caused by Swift::D failing to typecheck in `equals(_:_:)`: expected-error@-1 *{{extension outside of file declaring struct 'D' prevents automatic synthesis of '==' for protocol 'Equatable'}} expected-note@-1 *{{add stubs for conformance}}
+
   @_implements(Swift::Equatable, Swift::==(_:_:))
   // expected-error@-1 {{name cannot be qualified with module selector here}} {{34-41=}}
-  public static func equals(_: Swift::D, _: Swift::D) -> Swift::Bool { Swift::fatalError() }
-  
+
+  public static func equals(_: Swift::D, _: Swift::D) -> Swift::Bool {
+  // expected-error@-1 2{{type 'D' is not imported through module 'Swift'}}
+  // expected-note@-2 {{did you mean module 'ModuleSelectorTestingKit'?}} {{32-37=ModuleSelectorTestingKit}}
+  // expected-note@-3 {{did you mean module 'ModuleSelectorTestingKit'?}} {{45-50=ModuleSelectorTestingKit}}
+    Swift::fatalError()
+  }
+
   // FIXME: Add tests with autodiff @_differentiable(jvp:vjp:) and
   // @_derivative(of:)
   
@@ -128,6 +175,8 @@ extension D: @retroactive Swift::Equatable {
     }
     else {
       self = Swift::D(value: .Swift::min)
+      // FIXME improve: expected-error@-1 {{use of unresolved identifier 'Swift::D'}}
+      // expected-error@-2 {{cannot infer contextual base in reference to member 'Swift::min'}}
     }
     
     self.Swift::myNegate()
@@ -202,13 +251,16 @@ func main::decl1(
   // expected-error@-1 {{name of function declaration cannot be qualified with module selector}}
   main::p1: main::A,
   // expected-error@-1 {{argument label cannot be qualified with module selector}}
-  // FIXME access path: expected-error@-2 {{use of undeclared type 'main::A'}}
+  // FIXME access path: expected-error@-2 {{type 'A' is not imported through module 'main'}}
+  // FIXME access path: expected-note@-3 {{did you mean module 'ModuleSelectorTestingKit'?}} {{13-17=ModuleSelectorTestingKit}}
   main::label p2: main::A,
   // expected-error@-1 {{argument label cannot be qualified with module selector}}
-  // FIXME access path: expected-error@-2 {{use of undeclared type 'main::A'}}
+  // FIXME access path: expected-error@-2 {{type 'A' is not imported through module 'main'}}
+  // FIXME access path: expected-note@-3 {{did you mean module 'ModuleSelectorTestingKit'?}} {{19-23=ModuleSelectorTestingKit}}
   label main::p3: main::A
   // expected-error@-1 {{name of parameter declaration cannot be qualified with module selector}}
-  // FIXME access path: expected-error@-2 {{use of undeclared type 'main::A'}}
+  // FIXME access path: expected-error@-2 {{type 'A' is not imported through module 'main'}}
+  // FIXME access path: expected-note@-3 {{did you mean module 'ModuleSelectorTestingKit'?}} {{19-23=ModuleSelectorTestingKit}}
 ) {
   let main::decl1a = "a"
   // expected-error@-1 {{name of constant declaration cannot be qualified with module selector}}
@@ -292,7 +344,8 @@ class main::decl4<main::T> {}
 
 typealias main::decl5 = main::Bool
 // expected-error@-1 {{name of typealias declaration cannot be qualified with module selector}}
-// FIXME improve: expected-error@-2 {{use of undeclared type 'main::Bool'}}
+// expected-error@-2 {{type 'Bool' is not imported through module 'main'}}
+// expected-note@-3 {{did you mean module 'Swift'?}} {{25-29=Swift}}
 
 protocol main::decl6 {
   // expected-error@-1 {{name of protocol declaration cannot be qualified with module selector}}
@@ -333,7 +386,8 @@ struct Parent {
 
   typealias main::decl5 = main::Bool
   // expected-error@-1 {{name of typealias declaration cannot be qualified with module selector}}
-  // FIXME improve: expected-error@-2 {{use of undeclared type 'main::Bool'}}
+  // expected-error@-2 {{type 'Bool' is not imported through module 'main'}}
+  // expected-note@-3 {{did you mean module 'Swift'?}} {{27-31=Swift}}
 }
 
 @_swift_native_objc_runtime_base(main::BaseClass)
