Clang: Disable a completion test for LLVM/Clang 10

For the case

  struct Foo;
  void f(Foo *foo) { foo->/*COMPLETE-HERE*/ }

no completions are expected as "Foo" is only forward declared.

This seems to be handled correctly in current LLVM/Clang master
(upcoming version 11), but wasn't with previous versions as pointless
non-member-completions were returned.

As our workaround is not applicable anymore with LLVM/Clang 10, disable
the corresponding test for that version as we cannot do anything about
it.

Change-Id: Ia02696175d0d532e16bc16a1010821b4aed20f8b
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/tools/clangbackend/source/codecompleter.cpp

@@ -61,6 +61,8 @@ CodeCompletions toCodeCompletions(const UnsavedFile &unsavedFile,
     return codeCompletions;
 }
 
+// CLANG-UPGRADE-CHECK: Remove this workaround once we require LLVM/Clang 11 as that version makes
+// the workaround pointless.
 void filterUnknownContextResults(ClangCodeCompleteResults &results,
                                  const UnsavedFile &theUnsavedFile,
                                  uint line,

tests/unit/unittest/codecompleter-test.cpp

@@ -530,7 +530,9 @@ TEST_F(CodeCompleterSlowTest, NoDotArrowCorrectionForColonColon)
     ASSERT_THAT(completions, Not(Contains(HasFixIts())));
 }
 
-TEST_F(CodeCompleterSlowTest, NoGlobalCompletionAfterForwardDeclaredClassPointer)
+// Our workaround is not applicable with LLVM/Clang 10 anymore, so disable this test for that version.
+// Luckily, the workaround is not needed anymore with LLVM/Clang 11.
+TEST_F(CodeCompleterSlowTest, DISABLED_FOR_CLANG_10(NoGlobalCompletionAfterForwardDeclaredClassPointer))
 {
     auto myCompleter = setupCompleter(globalCompletionAfterForwardDeclaredClassPointer);
     const ClangBackEnd::CodeCompletions completions = myCompleter.complete(5, 10);

tests/unit/unittest/conditionally-disabled-tests.h

@@ -25,6 +25,14 @@
 
 #include <QtGlobal>
 
+#include <clang-c/Index.h>
+
+#if CINDEX_VERSION_MAJOR == 0 && CINDEX_VERSION_MINOR == 59
+#  define DISABLED_FOR_CLANG_10(x) DISABLED_##x
+#else
+#  define DISABLED_FOR_CLANG_10(x) x
+#endif
+
 #ifdef Q_OS_WIN
 #  define DISABLED_ON_WINDOWS(x) DISABLED_##x
 #else