test: Show failure when implicit member needs bad template instantiation

When a function template (or member of a class template) is instantiated
by an implicit class member definition, Clang delays the instantiation
for later handling by clang::Sema::PerformPendingInstantiations during
clang::Sema::ActOnEndOfTranslationUnit.  If the instantiation causes
errors they are not suppressed because our clang::Sema::SFINAETrap has
gone out of scope.

Even if we could keep a clang::Sema::SFINAETrap in scope, the
clang::Sema::InstantiatingTemplate::Initialize method sets
sema.InNonInstantiationSFINAEContext to false and adds an entry to
sema.ActiveTemplateInstantiations.  This prevents the
clang::Sema::EmitCurrentDiagnostic call to isSFINAEContext from
returning a valid SFINAE context, so errors are still not suppressed.

Add a test case demonstrating this known failure, and mark it as
"broken".  This will require changes to Clang to fix.

1 files changed, 1 insertions, 0 deletions

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index f386e41..11110ee 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -163,5 +163,6 @@ castxml_test_gccxml_c(Typedef-called-class)
 
 castxml_test_gccxml_c(invalid)
 
+castxml_test_gccxml_broken(Class-implicit-member-bad-base)
 castxml_test_gccxml_broken(Class-template-constructor-template)
 castxml_test_gccxml_broken(ReferenceType-to-Class-template)