Output: Desugar typedefs whose context is a template

In the code

    template <typename> struct A {
      struct B {
        typedef int intermediate_type;
        typedef intermediate_type type;
      };
    };

Clang represents `A<int>::B::type` as a typedef whose type is sugared to
`A<>::B::intermediate_type` where `A<>::B` is a non-template whose
context is an uninstantiated template `A<>` even though the original
typedef's context `A<int>::B` is a non-template whose context is an
instaniated template `A<int>`.

Since CastXML's gccxml output format does not support uninstantiated
templates we cannot represent the context of `intermediate_type` so we
must desugar it instead.  Otherwise we end up with an `Unimplemented`
node or even a crash in Clang because we perform operations meant for
non-templates on the template context.  We previously did this for
typedefs that appear directly in template contexts, but not for those
whose contexts are nominally non-template but contained in a template
context.  Fix the logic to loop through all nested contexts to perform
this check.

Closes: #70

1 files changed, 10 insertions, 5 deletions

diff --git a/src/Output.cxx b/src/Output.cxx
index e16d9b9..1736397 100644
--- a/src/Output.cxx
+++ b/src/Output.cxx
@@ -681,11 +681,14 @@ ASTVisitor::DumpId ASTVisitor::AddTypeDumpNode(DumpType dt, bool complete,
   case clang::Type::Typedef: {
     clang::TypedefType const* tdt = t->getAs<clang::TypedefType>();
     if(!tdt->isInstantiationDependentType() && tdt->isSugared()) {
-      if(clang::DeclContext const* tdc = tdt->getDecl()->getDeclContext()) {
-        if(clang::CXXRecordDecl const* tdx =
-           clang::dyn_cast<clang::CXXRecordDecl>(tdc)) {
-          if(tdx->getDescribedClassTemplate() ||
-             clang::isa<clang::ClassTemplatePartialSpecializationDecl>(tdx)
+      // Make sure all containing contexts are not templates.
+      clang::Decl const* d = tdt->getDecl();
+      while (clang::DeclContext const* tdc = d->getDeclContext()) {
+        if (clang::CXXRecordDecl const* tdx =
+            clang::dyn_cast<clang::CXXRecordDecl>(tdc)) {
+          d = tdx;
+          if (tdx->getDescribedClassTemplate() ||
+              clang::isa<clang::ClassTemplatePartialSpecializationDecl>(tdx)
              ) {
             // This TypedefType refers to a non-dependent
             // TypedefDecl member of a class template.  Since gccxml
@@ -694,6 +697,8 @@ ASTVisitor::DumpId ASTVisitor::AddTypeDumpNode(DumpType dt, bool complete,
             // referencing a class template as context.
             return this->AddTypeDumpNode(tdt->desugar(), complete, dq);
           }
+        } else {
+          break;
         }
       }
     }