Sema: Avoid emitting superfluous resilience diagnostics with MemberImportVisibility

include/swift/AST/SourceFile.h

@@ -507,6 +507,11 @@ class SourceFile final : public FileUnit {
     MissingImportForMemberDiagnostics[decl].push_back(loc);
   }
 
+  /// Returns true if there is a pending missing import diagnostic for \p decl.
+  bool hasDelayedMissingImportForMemberDiagnostic(const ValueDecl *decl) const {
+    return MissingImportForMemberDiagnostics.contains(decl);
+  }
+
   DelayedMissingImportForMemberDiags
   takeDelayedMissingImportForMemberDiagnostics() {
     DelayedMissingImportForMemberDiags diags;

lib/Sema/ResilienceDiagnostics.cpp

@@ -236,6 +236,7 @@ static bool diagnoseValueDeclRefExportability(SourceLoc loc, const ValueDecl *D,
 
   auto reason = where.getExportabilityReason();
   auto DC = where.getDeclContext();
+  auto SF = DC->getParentSourceFile();
   ASTContext &ctx = DC->getASTContext();
   auto originKind = getDisallowedOriginKind(D, where, downgradeToWarning);
 
@@ -275,16 +276,18 @@ static bool diagnoseValueDeclRefExportability(SourceLoc loc, const ValueDecl *D,
   if (originKind == DisallowedOriginKind::None)
     return false;
 
-  auto diagName = D->getName();
+  // Some diagnostics emitted with the `MemberImportVisibility` feature enabled
+  // subsume these diagnostics.
+  if (originKind == DisallowedOriginKind::MissingImport &&
+      ctx.LangOpts.hasFeature(Feature::MemberImportVisibility) && SF &&
+      SF->hasDelayedMissingImportForMemberDiagnostic(D))
+    return false;
+
   if (auto accessor = dyn_cast<AccessorDecl>(D)) {
     // Only diagnose accessors if their disallowed origin kind differs from
     // that of their storage.
     if (getDisallowedOriginKind(accessor->getStorage(), where) == originKind)
       return false;
-
-    // For accessors, diagnose with the name of the storage instead of the
-    // implicit '_'.
-    diagName = accessor->getStorage()->getName();
   }
 
   auto fragileKind = where.getFragileFunctionKind();

test/NameLookup/members_transitive_multifile_access_level.swift

@@ -60,9 +60,7 @@ extension Int {
   internal func usesTypealiasInInternalUsesOnly(x: TypealiasInInternalUsesOnly) {} // expected-error {{type alias 'TypealiasInInternalUsesOnly' is not available due to missing import of defining module 'InternalUsesOnly'}}
   package func usesTypealiasInPackageUsesOnly(x: TypealiasInPackageUsesOnly) {} // expected-error {{type alias 'TypealiasInPackageUsesOnly' is not available due to missing import of defining module 'PackageUsesOnly'}}
   public func usesTypealiasInPublicUsesOnly(x: TypealiasInPublicUsesOnly) {} // expected-error {{type alias 'TypealiasInPublicUsesOnly' is not available due to missing import of defining module 'PublicUsesOnly'}}
-  // expected-warning@-1 {{cannot use type alias 'TypealiasInPublicUsesOnly' here; 'PublicUsesOnly' was not imported by this file}}
   public func usesTypealiasInMixedUses(x: TypealiasInMixedUses) {} // expected-error {{type alias 'TypealiasInMixedUses' is not available due to missing import of defining module 'MixedUses'}}
-  // expected-warning@-1 {{cannot use type alias 'TypealiasInMixedUses' here; 'MixedUses' was not imported by this file}}
   internal func usesTypealiasInMixedUses_Internal(x: TypealiasInMixedUses) {} // expected-error {{type alias 'TypealiasInMixedUses' is not available due to missing import of defining module 'MixedUses'}}
 }
 
@@ -78,9 +76,7 @@ private func usesTypealiasInInternalUsesOnly_Private(x: Int.TypealiasInInternalU
 internal func usesTypealiasInInternalUsesOnly(x: Int.TypealiasInInternalUsesOnly) {} // expected-error {{type alias 'TypealiasInInternalUsesOnly' is not available due to missing import of defining module 'InternalUsesOnly'}}
 package func usesTypealiasInPackageUsesOnly(x: Int.TypealiasInPackageUsesOnly) {} // expected-error {{type alias 'TypealiasInPackageUsesOnly' is not available due to missing import of defining module 'PackageUsesOnly'}}
 public func usesTypealiasInPublicUsesOnly(x: Int.TypealiasInPublicUsesOnly) {} // expected-error {{type alias 'TypealiasInPublicUsesOnly' is not available due to missing import of defining module 'PublicUsesOnly'}}
-// expected-warning@-1 {{cannot use type alias 'TypealiasInPublicUsesOnly' here; 'PublicUsesOnly' was not imported by this file}}
 public func usesTypealiasInMixedUses(x: Int.TypealiasInMixedUses) {} // expected-error {{type alias 'TypealiasInMixedUses' is not available due to missing import of defining module 'MixedUses'}}
-// expected-warning@-1 {{cannot use type alias 'TypealiasInMixedUses' here; 'MixedUses' was not imported by this file}}
 internal func usesTypealiasInMixedUses_Internal(x: Int.TypealiasInMixedUses) {} // expected-error {{type alias 'TypealiasInMixedUses' is not available due to missing import of defining module 'MixedUses'}}
 
 //--- extensions.swift
@@ -104,12 +100,10 @@ extension Int.NestedInPackageUsesOnly { // expected-error {{struct 'NestedInPack
 }
 
 extension Int.NestedInPublicUsesOnly { // expected-error {{struct 'NestedInPublicUsesOnly' is not available due to missing import of defining module 'PublicUsesOnly'}}
-  // expected-warning@-1 {{cannot use struct 'NestedInPublicUsesOnly' in an extension with public or '@usableFromInline' members; 'PublicUsesOnly' was not imported by this file}}
   public func publicMethod() {}
 }
 
 extension Int.NestedInMixedUses { // expected-error {{struct 'NestedInMixedUses' is not available due to missing import of defining module 'MixedUses'}}
-  // expected-warning@-1 {{cannot use struct 'NestedInMixedUses' in an extension with public or '@usableFromInline' members; 'MixedUses' was not imported by this file}}
   public func publicMethod() {}
 }