Don't try and debug format blacklisted types when generating impl Debug blocks

Author: fitzgen

src/codegen/derive_debug.rs

@@ -53,7 +53,7 @@ pub fn gen_debug_impl(
                             impl X {
                                 fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
                                     write!(f, $format_string $tokens)
-                                }    
+                                }
                             });
 
     match impl_.unwrap().node {
@@ -127,6 +127,12 @@ impl<'a> ImplDebug<'a> for Item {
     ) -> Option<(String, Vec<TokenTree>)> {
         let name_ident = ctx.rust_ident_raw(name);
 
+        // We don't know if blacklisted items `impl Debug` or not, so we can't
+        // add them to the format string we're building up.
+        if !ctx.whitelisted_items().contains(&self.id()) {
+            return None;
+        }
+
         let ty = match self.as_type() {
             Some(ty) => ty,
             None => {
@@ -168,7 +174,7 @@ impl<'a> ImplDebug<'a> for Item {
                 } else {
                     debug_print(ctx, name, name_ident)
                 }
-            } 
+            }
 
             // The generic is not required to implement Debug, so we can not debug print that type
             TypeKind::TypeParam => {

tests/expectations/tests/blacklist-and-impl-debug.rs

@@ -0,0 +1,34 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+pub struct BlacklistMe(u8);
+
+/// Because this type contains a blacklisted type, it should not derive Debug.
+#[repr(C)]
+pub struct ShouldManuallyImplDebug {
+    pub a: BlacklistMe,
+}
+#[test]
+fn bindgen_test_layout_ShouldManuallyImplDebug() {
+    assert_eq!(::std::mem::size_of::<ShouldManuallyImplDebug>() , 1usize ,
+               concat ! (
+               "Size of: " , stringify ! ( ShouldManuallyImplDebug ) ));
+    assert_eq! (::std::mem::align_of::<ShouldManuallyImplDebug>() , 1usize ,
+                concat ! (
+                "Alignment of " , stringify ! ( ShouldManuallyImplDebug ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const ShouldManuallyImplDebug ) ) . a as *
+                const _ as usize } , 0usize , concat ! (
+                "Alignment of field: " , stringify ! ( ShouldManuallyImplDebug
+                ) , "::" , stringify ! ( a ) ));
+}
+impl Default for ShouldManuallyImplDebug {
+    fn default() -> Self { unsafe { ::std::mem::zeroed() } }
+}
+impl ::std::fmt::Debug for ShouldManuallyImplDebug {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f , "ShouldManuallyImplDebug {{  }}")
+    }
+}

tests/headers/blacklist-and-impl-debug.hpp

@@ -0,0 +1,10 @@
+// bindgen-flags: --impl-debug --blacklist-type BlacklistMe --raw-line 'pub struct BlacklistMe(u8);'
+
+struct BlacklistMe {};
+
+/**
+ * Because this type contains a blacklisted type, it should not derive Debug.
+ */
+struct ShouldManuallyImplDebug {
+    BlacklistMe a;
+};