Trace function signature types

This extends the `TypeCollector` trait implementation for `Item` to
consider items of kind `Function` and to collect the types found in the
function's signature.

Fixes #291

1 files changed, 5 insertions, 0 deletions

diff --git a/libbindgen/src/ir/item.rs b/libbindgen/src/ir/item.rs
index d96936ad..b857acf9 100644
--- a/libbindgen/src/ir/item.rs
+++ b/libbindgen/src/ir/item.rs
@@ -142,6 +142,11 @@ impl TypeCollector for Item {
                     ty.collect_types(ctx, types, self);
                 }
             }
+            ItemKind::Function(ref fun) => {
+                if !self.is_opaque(ctx) {
+                    types.insert(fun.signature());
+                }
+            }
             _ => {} // FIXME.
         }
     }