Auto merge of #293 - fitzgen:type-referenced-by-whitelisted-function, r=emilio

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

r? @emilio

Author: bors-servo

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.
         }
     }

libbindgen/tests/expectations/tests/type-referenced-by-whitelisted-function.rs

@@ -0,0 +1,22 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(non_snake_case)]
+
+
+#[repr(C)]
+#[derive(Debug, Copy)]
+pub struct dl_phdr_info {
+    pub x: ::std::os::raw::c_int,
+}
+#[test]
+fn bindgen_test_layout_dl_phdr_info() {
+    assert_eq!(::std::mem::size_of::<dl_phdr_info>() , 4usize);
+    assert_eq!(::std::mem::align_of::<dl_phdr_info>() , 4usize);
+}
+impl Clone for dl_phdr_info {
+    fn clone(&self) -> Self { *self }
+}
+extern "C" {
+    pub fn dl_iterate_phdr(arg1: *mut dl_phdr_info) -> ::std::os::raw::c_int;
+}

libbindgen/tests/headers/type-referenced-by-whitelisted-function.h

@@ -0,0 +1,7 @@
+// bindgen-flags: --whitelist-function dl_iterate_phdr
+
+struct dl_phdr_info {
+    int x;
+};
+
+int dl_iterate_phdr(struct dl_phdr_info *);