Merge pull request #8147 from d-ronnqvist/SR-2409

[SR-2409] Rephrase diagnostic to consider Objective-C interop

Author: jrose-apple

include/swift/AST/DiagnosticsClangImporter.def

@@ -44,7 +44,7 @@ NOTE(note_from_clang,none,
   "%0", (StringRef))
 
 ERROR(clang_cannot_build_module,Fatal,
-  "could not build Objective-C module '%0'", (StringRef))
+  "could not build %select{C|Objective-C}0 module '%1'", (bool, StringRef))
 
 ERROR(bridging_header_missing,Fatal,
   "bridging header '%0' does not exist", (StringRef))

lib/ClangImporter/ClangDiagnosticConsumer.cpp

@@ -173,6 +173,7 @@ void ClangDiagnosticConsumer::HandleDiagnostic(
                                   clangDiag.getLocation());
 
     ctx.Diags.diagnose(loc, diag::clang_cannot_build_module,
+                       ctx.LangOpts.EnableObjCInterop,
                        CurrentImport->getName());
     return;
   }

test/ClangImporter/non-modular-include.swift

@@ -1,8 +1,9 @@
 // RUN: rm -rf %t && mkdir -p %t
-// RUN: not %target-swift-frontend -typecheck %s -I %S/Inputs/non-modular -F %S/Inputs/non-modular 2>&1 | %FileCheck %s
+// RUN: not %target-swift-frontend -typecheck %s -I %S/Inputs/non-modular -F %S/Inputs/non-modular 2>&1 | %FileCheck --check-prefix=CHECK --check-prefix=CHECK-%target-runtime %s
 
 // CHECK: {{.+}}/non-modular/Foo.framework/Headers/Foo.h:1:9: error: include of non-modular header inside framework module 'Foo'
-// CHECK: error: could not build Objective-C module 'Foo'
+// CHECK-objc: error: could not build Objective-C module 'Foo'
+// CHECK-native: error: could not build C module 'Foo'
 // CHECK-NOT: error
 
 import Foo