Sema: Diagnose missing imports in during type lookup.

Author: tshortli

lib/Sema/TypeCheckType.cpp

@@ -30,6 +30,7 @@
 #include "swift/AST/ExistentialLayout.h"
 #include "swift/AST/ForeignErrorConvention.h"
 #include "swift/AST/GenericEnvironment.h"
+#include "swift/AST/Module.h"
 #include "swift/AST/NameLookup.h"
 #include "swift/AST/PackExpansionMatcher.h"
 #include "swift/AST/ParameterList.h"
@@ -1364,8 +1365,14 @@ static Type diagnoseUnknownType(TypeResolution resolution,
     if (!inaccessibleResults.empty()) {
       // FIXME: What if the unviable candidates have different levels of access?
       auto first = cast<TypeDecl>(inaccessibleResults.front().getValueDecl());
-      diags.diagnose(repr->getNameLoc(), diag::candidate_inaccessible,
-                     first, first->getFormalAccess());
+      auto formalAccess = first->getFormalAccess();
+      auto nameLoc = repr->getNameLoc();
+      if (formalAccess >= AccessLevel::Public &&
+          diagnoseMissingImportForMember(first, dc, nameLoc.getStartLoc()))
+        return ErrorType::get(ctx);
+
+      diags.diagnose(nameLoc, diag::candidate_inaccessible, first,
+                     formalAccess);
 
       // FIXME: If any of the candidates (usually just one) are in the same
       // module we could offer a fix-it.
@@ -1454,8 +1461,13 @@ static Type diagnoseUnknownType(TypeResolution resolution,
   if (inaccessibleMembers) {
     // FIXME: What if the unviable candidates have different levels of access?
     const TypeDecl *first = inaccessibleMembers.front().Member;
-    diags.diagnose(repr->getNameLoc(), diag::candidate_inaccessible,
-                   first, first->getFormalAccess());
+    auto formalAccess = first->getFormalAccess();
+    auto nameLoc = repr->getNameLoc();
+    if (formalAccess >= AccessLevel::Public &&
+        diagnoseMissingImportForMember(first, dc, nameLoc.getStartLoc()))
+      return ErrorType::get(ctx);
+
+    diags.diagnose(nameLoc, diag::candidate_inaccessible, first, formalAccess);
 
     // FIXME: If any of the candidates (usually just one) are in the same module
     // we could offer a fix-it.

test/NameLookup/Inputs/members_A.swift

@@ -18,6 +18,8 @@ extension X {
   public var propXinA: Bool { return true }
 
   public static func <<<(a: Self, b: Self) -> Self { a }
+
+  public struct NestedInA {}
 }
 
 extension Y {

test/NameLookup/Inputs/members_B.swift

@@ -7,6 +7,8 @@ extension X {
   public var propXinB: Bool { return true }
 
   public static func >>>(a: Self, b: Self) -> Self { b }
+
+  public struct NestedInB {}
 }
 
 extension Y {

test/NameLookup/Inputs/members_C.swift

@@ -8,6 +8,8 @@ extension X {
   public var propXinC: Bool { return true }
 
   public static func <>(a: Self, b: Self) -> Self { a }
+
+  public struct NestedInC {}
 }
 
 extension Y {

test/NameLookup/members_transitive.swift

@@ -46,4 +46,24 @@ extension X {
       propXinC
     )
   }
+
+  func testNestedTypes() {
+    _ = NestedInA.self
+    _ = NestedInB.self // expected-member-visibility-error{{struct 'NestedInB' is not available due to missing import of defining module 'members_B'}}
+    _ = NestedInC.self
+  }
+
+  var nestedInA: NestedInA { fatalError() }
+  var nestedInB: NestedInB { fatalError() } // expected-member-visibility-error{{struct 'NestedInB' is not available due to missing import of defining module 'members_B'}}
+  var nestedInC: NestedInC { fatalError() }
+}
+
+extension X.NestedInA {}
+extension X.NestedInB {} // expected-member-visibility-error{{struct 'NestedInB' is not available due to missing import of defining module 'members_B'}}
+extension X.NestedInC {}
+
+func testTopLevelTypes() {
+  _ = EnumInA.self
+  _ = EnumInB.self // expected-error{{cannot find 'EnumInB' in scope}}
+  _ = EnumInC.self
 }