Auto merge of #835 - emilio:tp-function, r=fitzgen

 	ir: We really need to traverse all edges for the used template parameter analysis to be sound.

Fixes #833

Author: bors-servo

src/ir/context.rs

@@ -219,7 +219,7 @@ impl<'ctx, 'gen> WhitelistedItems<'ctx, 'gen>
         where R: IntoIterator<Item = ItemId>,
     {
         let predicate = if ctx.options().whitelist_recursively {
-            traversal::codegen_edges
+            traversal::all_edges
         } else {
             traversal::no_edges
         };

src/ir/traversal.rs

@@ -201,34 +201,6 @@ pub fn all_edges(_: &BindgenContext, _: Edge) -> bool {
     true
 }
 
-/// A `TraversalPredicate` implementation that only follows edges to items that
-/// are enabled for code generation. This lets us skip considering items for
-/// which we won't generate any bindings to.
-pub fn codegen_edges(ctx: &BindgenContext, edge: Edge) -> bool {
-    let cc = &ctx.options().codegen_config;
-    match edge.kind {
-        EdgeKind::Generic => ctx.resolve_item(edge.to).is_enabled_for_codegen(ctx),
-
-        // We statically know the kind of item that non-generic edges can point
-        // to, so we don't need to actually resolve the item and check
-        // `Item::is_enabled_for_codegen`.
-        EdgeKind::TemplateParameterDefinition |
-        EdgeKind::TemplateArgument |
-        EdgeKind::TemplateDeclaration |
-        EdgeKind::BaseMember |
-        EdgeKind::Field |
-        EdgeKind::InnerType |
-        EdgeKind::FunctionReturn |
-        EdgeKind::FunctionParameter |
-        EdgeKind::VarType |
-        EdgeKind::TypeReference => cc.types,
-        EdgeKind::InnerVar => cc.vars,
-        EdgeKind::Method => cc.methods,
-        EdgeKind::Constructor => cc.constructors,
-        EdgeKind::Destructor => cc.destructors,
-    }
-}
-
 /// A `TraversalPredicate` implementation that never follows any edges, and
 /// therefore traversals using this predicate will only visit the traversal's
 /// roots.

tests/expectations/tests/issue-833.rs

@@ -0,0 +1,10 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+#[repr(C)] pub struct nsTArray<T> { pub hdr: *const T }
+
+extern "C" {
+    pub fn func() -> *mut nsTArray<::std::os::raw::c_int>;
+}

tests/headers/issue-833.hpp

@@ -0,0 +1,8 @@
+// bindgen-flags: --generate functions --whitelist-function func --raw-line "#[repr(C)] pub struct nsTArray<T> { pub hdr: *const T }"
+
+template<typename T>
+class nsTArray {
+  T* mHeader;
+};
+
+extern "C" nsTArray<int>* func();