Auto merge of #1059 - aeleos:master, r=fitzgen

Remove early anonymous bitfield filtering and consolidate name method

This PR is some changes to early bitfield filtering to help fix (#1007) This does not close (#1007), but allows for checking if the bitfield is too large during a later stage.

@fitzgen r?

Author: bors-servo

src/codegen/impl_debug.rs

@@ -95,11 +95,14 @@ impl<'a> ImplDebug<'a> for BitfieldUnit {
             if i > 0 {
                 format_string.push_str(", ");
             }
-            format_string.push_str(&format!("{} : {{:?}}", bu.name()));
-            let name_ident = ctx.rust_ident_raw(bu.name());
-            tokens.push(quote! {
-                self.#name_ident ()
-            });
+
+            if let Some(name) = bu.name() {
+                format_string.push_str(&format!("{} : {{:?}}", name));
+                let name_ident = ctx.rust_ident_raw(name);
+                tokens.push(quote! {
+                    self.#name_ident ()
+                });
+            }
         }
 
         Some((format_string, tokens))

src/codegen/impl_partialeq.rs

@@ -51,10 +51,12 @@ pub fn gen_partialeq_impl(
                     tokens.push(gen_field(ctx, ty_item, name));
                 }
                 Field::Bitfields(ref bu) => for bitfield in bu.bitfields() {
-                    let name_ident = ctx.rust_ident_raw(bitfield.name());
-                    tokens.push(quote! {
-                        self.#name_ident () == other.#name_ident ()
-                    });
+                    if let Some(name) = bitfield.name() {
+                        let name_ident = ctx.rust_ident_raw(name);
+                        tokens.push(quote! {
+                            self.#name_ident () == other.#name_ident ()
+                        });
+                    }
                 },
             }
         }

src/codegen/mod.rs

@@ -1185,6 +1185,10 @@ impl<'a> FieldCodegen<'a> for BitfieldUnit {
         let mut ctor_impl = quote! { 0 };
 
         for bf in self.bitfields() {
+            // Codegen not allowed for anonymous bitfields
+            if bf.name().is_none() {
+                continue;
+            }
             bf.codegen(
                 ctx,
                 fields_should_be_private,
@@ -1198,7 +1202,7 @@ impl<'a> FieldCodegen<'a> for BitfieldUnit {
                 (&unit_field_name, unit_field_int_ty.clone()),
             );
 
-            let param_name = bitfield_getter_name(ctx, parent, bf.name());
+            let param_name = bitfield_getter_name(ctx, parent, bf.name().unwrap());
             let bitfield_ty_item = ctx.resolve_item(bf.ty());
             let bitfield_ty = bitfield_ty_item.expect_type();
             let bitfield_ty =
@@ -1307,9 +1311,11 @@ impl<'a> FieldCodegen<'a> for Bitfield {
         F: Extend<quote::Tokens>,
         M: Extend<quote::Tokens>,
     {
+        // Should never be called with name() as None, as codegen can't be done
+        // on an anonymous bitfield
         let prefix = ctx.trait_prefix();
-        let getter_name = bitfield_getter_name(ctx, parent, self.name());
-        let setter_name = bitfield_setter_name(ctx, parent, self.name());
+        let getter_name = bitfield_getter_name(ctx, parent, self.name().unwrap());
+        let setter_name = bitfield_setter_name(ctx, parent, self.name().unwrap());
         let unit_field_ident = quote::Ident::new(unit_field_name);
 
         let bitfield_ty_item = ctx.resolve_item(self.ty());

src/ir/comp.rs

@@ -276,7 +276,7 @@ impl DotAttributes for Bitfield {
         writeln!(
             out,
             "<tr><td>{} : {}</td><td>{:?}</td></tr>",
-            self.name(),
+            self.name().unwrap_or("(anonymous)"),
             self.width(),
             self.ty()
         )
@@ -298,7 +298,6 @@ impl Bitfield {
     /// Construct a new bitfield.
     fn new(offset_into_unit: usize, raw: RawField) -> Bitfield {
         assert!(raw.bitfield().is_some());
-        assert!(raw.name().is_some());
 
         Bitfield {
             offset_into_unit: offset_into_unit,
@@ -332,11 +331,6 @@ impl Bitfield {
     pub fn width(&self) -> u32 {
         self.data.bitfield().unwrap()
     }
-
-    /// Get the name of this bitfield.
-    pub fn name(&self) -> &str {
-        self.data.name().unwrap()
-    }
 }
 
 impl FieldMethods for Bitfield {
@@ -581,13 +575,12 @@ fn bitfields_to_allocation_units<E, I>(
             }
         }
 
-        // Only keep named bitfields around. Unnamed bitfields (with > 0
-        // bitsize) are used for padding. Because the `Bitfield` struct stores
-        // the bit-offset into its allocation unit where its bits begin, we
-        // don't need any padding bits hereafter.
-        if bitfield.name().is_some() {
-            bitfields_in_unit.push(Bitfield::new(offset, bitfield));
-        }
+        // Always keep all bitfields around. While unnamed bitifields are used
+        // for padding (and usually not needed hereafter), large unnamed
+        // bitfields over their types size cause weird allocation size behavior from clang.
+        // Therefore, all bitfields needed to be kept around in order to check for this
+        // and make the struct opaque in this case
+        bitfields_in_unit.push(Bitfield::new(offset, bitfield));
 
         max_align = cmp::max(max_align, bitfield_align);
 

tests/expectations/tests/bitfield_large_overflow.rs

@@ -18,4 +18,3 @@ extern "C" {
     #[link_name = "a"]
     pub static mut a: _bindgen_ty_1;
 }
-