Simplify is_constified_enum_module

Used suggested code from @emilio and also added a test for an alias to
an anonymous enum.

3 files changed, 70 insertions, 37 deletions

diff --git a/src/ir/item.rs b/src/ir/item.rs
index 7d033210..de629e03 100644
--- a/src/ir/item.rs
+++ b/src/ir/item.rs
@@ -829,46 +829,32 @@ impl Item {
 
     /// Returns whether the item is a constified module enum
     fn is_constified_enum_module(&self, ctx: &BindgenContext) -> bool {
-        if let ItemKind::Type(ref type_) = self.kind {
-            // Do not count an "alias of an alias" as a constified module enum;
-            // otherwise, we will get:
-            //   pub mod foo {
-            //      pub type Type = ::std::os::raw::c_uint;
-            //      ...
-            //   }
-            //   pub use foo::Type as foo_alias1;
-            //   pub use foo_alias1::Type as foo_alias2;
-            //   pub use foo_alias2::Type as foo_alias3;
-            //   ...
-            //
-            // (We do not want the '::Type' appended to the alias types; only the base type)
-            if let TypeKind::Alias(inner_id) = *type_.kind() {
-                let inner_item = ctx.resolve_item(inner_id);
-                if let ItemKind::Type(ref inner_type) = *inner_item.kind() {
-                    match *inner_type.kind() {
-                        TypeKind::Alias(..) => { return false; }
-                        TypeKind::ResolvedTypeRef(resolved_id) => {
-                            // We need to handle:
-                            // Alias -> ResolvedTypeRef -> Alias
-                            let resolved_item = ctx.resolve_item(resolved_id);
-                            if let ItemKind::Type(ref resolved_type) = *resolved_item.kind() {
-                                if let TypeKind::Alias(..) = *resolved_type.kind() {
-                                    return false;
-                                }
-                            }
-                        }
-                        _ => (),
-                    }
-                }
+        // Do not jump through aliases, except for aliases that point to a type
+        // with the same name, since we dont generate coe for them.
+        let item = self.id.into_resolver().through_type_refs().resolve(ctx);
+        let type_ = match *item.kind() {
+            ItemKind::Type(ref type_) => type_,
+            _ => return false,
+        };
+
+        match *type_.kind() {
+            TypeKind::Enum(ref enum_) => {
+                enum_.is_constified_enum_module(ctx, self)
             }
-            if let Some(ref type_) = type_.safe_canonical_type(ctx) {
-                if let TypeKind::Enum(ref enum_) = *type_.kind() {
-                    return enum_.is_constified_enum_module(ctx, self);
+            TypeKind::Alias(inner_id) => {
+                // TODO(emilio): Make this "hop through type aliases that aren't
+                // really generated" an option in `ItemResolver`?
+                let inner_item = ctx.resolve_item(inner_id);
+                let name = item.canonical_name(ctx);
+
+                if inner_item.canonical_name(ctx) == name {
+                    inner_item.is_constified_enum_module(ctx)
+                } else {
+                    false
                 }
             }
+            _ => false,
         }
-
-        return false;
     }
 }
 
diff --git a/tests/expectations/tests/constify-module-enums-types.rs b/tests/expectations/tests/constify-module-enums-types.rs
index db236d6f..4eb100c4 100644
--- a/tests/expectations/tests/constify-module-enums-types.rs
+++ b/tests/expectations/tests/constify-module-enums-types.rs
@@ -12,6 +12,12 @@ pub mod foo {
     pub const ALSO_THIS: Type = 42;
     pub const AND_ALSO_THIS: Type = 42;
 }
+pub mod anon_enum {
+    pub type Type = ::std::os::raw::c_uint;
+    pub const Variant1: Type = 0;
+    pub const Variant2: Type = 1;
+    pub const Variant3: Type = 2;
+}
 pub mod ns1_foo {
     pub type Type = ::std::os::raw::c_uint;
     pub const THIS: Type = 0;
@@ -27,6 +33,9 @@ pub mod ns2_Foo {
 pub use self::foo::Type as foo_alias1;
 pub use self::foo_alias1 as foo_alias2;
 pub use self::foo_alias2 as foo_alias3;
+pub use self::anon_enum::Type as anon_enum_alias1;
+pub use self::anon_enum_alias1 as anon_enum_alias2;
+pub use self::anon_enum_alias2 as anon_enum_alias3;
 #[repr(C)]
 #[derive(Debug, Copy)]
 pub struct bar {
@@ -36,10 +45,14 @@ pub struct bar {
     pub member4: foo_alias3,
     pub member5: ns1_foo::Type,
     pub member6: *mut ns2_Foo::Type,
+    pub member7: anon_enum::Type,
+    pub member8: anon_enum_alias1,
+    pub member9: anon_enum_alias2,
+    pub member10: anon_enum_alias3,
 }
 #[test]
 fn bindgen_test_layout_bar() {
-    assert_eq!(::std::mem::size_of::<bar>() , 32usize , concat ! (
+    assert_eq!(::std::mem::size_of::<bar>() , 48usize , concat ! (
                "Size of: " , stringify ! ( bar ) ));
     assert_eq! (::std::mem::align_of::<bar>() , 8usize , concat ! (
                 "Alignment of " , stringify ! ( bar ) ));
@@ -73,6 +86,26 @@ fn bindgen_test_layout_bar() {
                 , 24usize , concat ! (
                 "Alignment of field: " , stringify ! ( bar ) , "::" ,
                 stringify ! ( member6 ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const bar ) ) . member7 as * const _ as usize }
+                , 32usize , concat ! (
+                "Alignment of field: " , stringify ! ( bar ) , "::" ,
+                stringify ! ( member7 ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const bar ) ) . member8 as * const _ as usize }
+                , 36usize , concat ! (
+                "Alignment of field: " , stringify ! ( bar ) , "::" ,
+                stringify ! ( member8 ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const bar ) ) . member9 as * const _ as usize }
+                , 40usize , concat ! (
+                "Alignment of field: " , stringify ! ( bar ) , "::" ,
+                stringify ! ( member9 ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const bar ) ) . member10 as * const _ as usize
+                } , 44usize , concat ! (
+                "Alignment of field: " , stringify ! ( bar ) , "::" ,
+                stringify ! ( member10 ) ));
 }
 impl Clone for bar {
     fn clone(&self) -> Self { *self }
diff --git a/tests/headers/constify-module-enums-types.hpp b/tests/headers/constify-module-enums-types.hpp
index 1618b269..2c652499 100644
--- a/tests/headers/constify-module-enums-types.hpp
+++ b/tests/headers/constify-module-enums-types.hpp
@@ -8,6 +8,12 @@ typedef enum foo {
   AND_ALSO_THIS = 42,
 } foo;
 
+
+typedef enum {
+  Variant1, Variant2, Variant3,
+} anon_enum;
+
+
 namespace ns1 {
   typedef enum {
     THIS,
@@ -28,6 +34,10 @@ typedef foo foo_alias1;
 typedef foo_alias1 foo_alias2;
 typedef foo_alias2 foo_alias3;
 
+typedef anon_enum anon_enum_alias1;
+typedef anon_enum_alias1 anon_enum_alias2;
+typedef anon_enum_alias2 anon_enum_alias3;
+
 typedef struct bar {
   foo member1;
   foo_alias1 member2;
@@ -35,6 +45,10 @@ typedef struct bar {
   foo_alias3 member4;
   ns1::foo member5;
   ns2::Foo *member6;
+  anon_enum member7;
+  anon_enum_alias1 member8;
+  anon_enum_alias2 member9;
+  anon_enum_alias3 member10;
 } bar;
 
 class Baz {