Auto merge of #842 - emilio:derive-debug-opaque-inst, r=Manishearth

analysis: Account for template instantiations of opaque types in the derive debug analysis.

We have a special-case for them in codegen to generate a blob, that can derive
debug.

This is a regression from #824, and hit stylo.

Author: bors-servo

src/ir/analysis/derive_debug.rs

@@ -4,6 +4,7 @@ use super::{ConstrainResult, MonotoneFramework};
 use std::collections::HashSet;
 use std::collections::HashMap;
 use ir::context::{BindgenContext, ItemId};
+use ir::item::IsOpaque;
 use ir::traversal::EdgeKind;
 use ir::ty::RUST_DERIVE_IN_ARRAY_LIMIT;
 use ir::ty::TypeKind;
@@ -260,19 +261,23 @@ impl<'ctx, 'gen> MonotoneFramework for CannotDeriveDebug<'ctx, 'gen> {
                     return self.insert(id);
                 }
 
-                let ty_cannot_derive = template.template_definition()
+                let template_definition = template.template_definition()
                     .into_resolver()
                     .through_type_refs()
                     .through_type_aliases()
-                    .resolve(self.ctx)
+                    .resolve(self.ctx);
+
+                let ty_cannot_derive = template_definition
                     .as_type()
                     .expect("Instantiations of a non-type?")
                     .as_comp()
                     .and_then(|c| {
-                        // For non-type template parameters, we generate an opaque
-                        // blob, and in this case the instantiation has a better
-                        // idea of the layout than the definition does.
-                        if c.has_non_type_template_params() {
+                        // For non-type template parameters, or opaque template
+                        // definitions, we generate an opaque blob, and in this
+                        // case the instantiation has a better idea of the
+                        // layout than the definition does.
+                        if template_definition.is_opaque(self.ctx, &()) ||
+                            c.has_non_type_template_params() {
                             let opaque = ty.layout(self.ctx)
                                 .or_else(|| {
                                     self.ctx

tests/expectations/tests/opaque-template-inst-member.rs

@@ -0,0 +1,41 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct OpaqueTemplate {
+}
+impl Default for OpaqueTemplate {
+    fn default() -> Self { unsafe { ::std::mem::zeroed() } }
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct ContainsOpaqueTemplate {
+    pub mBlah: [u32; 11usize],
+    pub mBaz: ::std::os::raw::c_int,
+}
+#[test]
+fn bindgen_test_layout_ContainsOpaqueTemplate() {
+    assert_eq!(::std::mem::size_of::<ContainsOpaqueTemplate>() , 48usize ,
+               concat ! ( "Size of: " , stringify ! ( ContainsOpaqueTemplate )
+               ));
+    assert_eq! (::std::mem::align_of::<ContainsOpaqueTemplate>() , 4usize ,
+                concat ! (
+                "Alignment of " , stringify ! ( ContainsOpaqueTemplate ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const ContainsOpaqueTemplate ) ) . mBlah as *
+                const _ as usize } , 0usize , concat ! (
+                "Alignment of field: " , stringify ! ( ContainsOpaqueTemplate
+                ) , "::" , stringify ! ( mBlah ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const ContainsOpaqueTemplate ) ) . mBaz as *
+                const _ as usize } , 44usize , concat ! (
+                "Alignment of field: " , stringify ! ( ContainsOpaqueTemplate
+                ) , "::" , stringify ! ( mBaz ) ));
+}
+impl Clone for ContainsOpaqueTemplate {
+    fn clone(&self) -> Self { *self }
+}

tests/headers/opaque-template-inst-member.hpp

@@ -0,0 +1,12 @@
+// bindgen-flags: --opaque-type 'OpaqueTemplate'
+
+template<typename T>
+class OpaqueTemplate {
+    T mData;
+    bool mCannotDebug[40];
+};
+
+class ContainsOpaqueTemplate {
+    OpaqueTemplate<int> mBlah;
+    int mBaz;
+};