Auto merge of #890 - photoszzt:clean_up_trivially_debug, r=emilio

Clean up trivially derive debug

r? @fitzgen

Author: bors-servo

src/ir/analysis/derive_debug.rs

@@ -130,7 +130,7 @@ impl<'ctx, 'gen> MonotoneFramework for CannotDeriveDebug<'ctx, 'gen> {
 
         if ty.is_opaque(self.ctx, item) {
             let layout_can_derive = ty.layout(self.ctx).map_or(true, |l| {
-                l.opaque().can_trivially_derive_debug(self.ctx, ())
+                l.opaque().can_trivially_derive_debug()
             });
             return if layout_can_derive {
                 trace!("    we can trivially derive Debug for the layout");
@@ -215,7 +215,7 @@ impl<'ctx, 'gen> MonotoneFramework for CannotDeriveDebug<'ctx, 'gen> {
 
                     if ty.layout(self.ctx)
                         .map_or(true,
-                                |l| l.opaque().can_trivially_derive_debug(self.ctx, ())) {
+                                |l| l.opaque().can_trivially_derive_debug()) {
                         trace!("    union layout can trivially derive Debug");
                         return ConstrainResult::Same;
                     } else {
@@ -260,7 +260,7 @@ impl<'ctx, 'gen> MonotoneFramework for CannotDeriveDebug<'ctx, 'gen> {
             TypeKind::Pointer(inner) => {
                 let inner_type = self.ctx.resolve_type(inner).canonical_type(self.ctx);
                 if let TypeKind::Function(ref sig) = *inner_type.kind() {
-                    if !sig.can_trivially_derive_debug(&self.ctx, ()) {
+                    if !sig.can_trivially_derive_debug() {
                         trace!("    function pointer that can't trivially derive Debug");
                         return self.insert(id);
                     }

src/ir/derive.rs

@@ -20,16 +20,9 @@ pub trait CanDeriveDebug {
 /// implementing this trait cannot use recursion or lookup result from fix point
 /// analysis. It's a helper trait for fix point analysis.
 pub trait CanTriviallyDeriveDebug {
-
-    /// Serve the same purpose as the Extra in CanDeriveDebug.
-    type Extra;
-
     /// Return `true` if `Debug` can be derived for this thing, `false`
     /// otherwise.
-    fn can_trivially_derive_debug(&self,
-                        ctx: &BindgenContext,
-                        extra: Self::Extra)
-                        -> bool;
+    fn can_trivially_derive_debug(&self) -> bool;
 }
 
 /// A trait that encapsulates the logic for whether or not we can derive `Copy`

src/ir/function.rs

@@ -480,9 +480,7 @@ impl Trace for FunctionSig {
 //
 // Note that copy is always derived, so we don't need to implement it.
 impl CanTriviallyDeriveDebug for FunctionSig {
-    type Extra = ();
-
-    fn can_trivially_derive_debug(&self, _ctx: &BindgenContext, _: ()) -> bool {
+    fn can_trivially_derive_debug(&self) -> bool {
         const RUST_DERIVE_FUNPTR_LIMIT: usize = 12;
         if self.argument_types.len() > RUST_DERIVE_FUNPTR_LIMIT {
             return false;

src/ir/layout.rs

@@ -104,9 +104,7 @@ impl Opaque {
 }
 
 impl CanTriviallyDeriveDebug for Opaque {
-    type Extra = ();
-
-    fn can_trivially_derive_debug(&self, _: &BindgenContext, _: ()) -> bool {
+    fn can_trivially_derive_debug(&self) -> bool {
         self.array_size()
             .map_or(false, |size| size <= RUST_DERIVE_IN_ARRAY_LIMIT)
     }