Adds `--constified-enum-module` option per #699

7 files changed, 181 insertions, 11 deletions

diff --git a/src/codegen/mod.rs b/src/codegen/mod.rs
index 86aafa39..8f9f0ee7 100644
--- a/src/codegen/mod.rs
+++ b/src/codegen/mod.rs
@@ -36,9 +36,12 @@ use std::mem;
 use std::ops;
 use syntax::abi;
 use syntax::ast;
-use syntax::codemap::{Span, respan};
+use syntax::codemap::{DUMMY_SP, Span, respan};
 use syntax::ptr::P;
 
+// Name of type defined in constified enum module
+pub static CONSTIFIED_ENUM_MODULE_REPR_NAME: &'static str = "Type";
+
 fn root_import_depth(ctx: &BindgenContext, item: &Item) -> usize {
     if !ctx.options().enable_cxx_namespaces {
         return 0;
@@ -244,7 +247,6 @@ impl ForeignModBuilder {
     }
 
     fn build(self, ctx: &BindgenContext) -> P<ast::Item> {
-        use syntax::codemap::DUMMY_SP;
         P(ast::Item {
             ident: ctx.rust_ident(""),
             id: ast::DUMMY_NODE_ID,
@@ -2001,6 +2003,10 @@ enum EnumBuilder<'a> {
         aster: P<ast::Item>,
     },
     Consts { aster: P<ast::Item> },
+    ModuleConsts {
+        module_name: &'a str,
+        module_items: Vec<P<ast::Item>>,
+    },
 }
 
 impl<'a> EnumBuilder<'a> {
@@ -2010,7 +2016,8 @@ impl<'a> EnumBuilder<'a> {
            name: &'a str,
            repr: P<ast::Ty>,
            bitfield_like: bool,
-           constify: bool)
+           constify: bool,
+           constify_module: bool)
            -> Self {
         if bitfield_like {
             EnumBuilder::Bitfield {
@@ -2022,8 +2029,20 @@ impl<'a> EnumBuilder<'a> {
                     .build(),
             }
         } else if constify {
-            EnumBuilder::Consts {
-                aster: aster.type_(name).build_ty(repr),
+            if constify_module {
+                let type_definition = aster::item::ItemBuilder::new()
+                    .pub_()
+                    .type_(CONSTIFIED_ENUM_MODULE_REPR_NAME)
+                    .build_ty(repr);
+
+                EnumBuilder::ModuleConsts {
+                    module_name: name,
+                    module_items: vec![type_definition],
+                }
+            } else  {
+                EnumBuilder::Consts {
+                    aster: aster.type_(name).build_ty(repr),
+                }
             }
         } else {
             EnumBuilder::Rust(aster.enum_(name))
@@ -2095,6 +2114,27 @@ impl<'a> EnumBuilder<'a> {
                 result.push(constant);
                 self
             }
+            EnumBuilder::ModuleConsts { module_name, module_items, .. } => {
+                // Variant type
+                let inside_module_type =
+                    aster::AstBuilder::new().ty().id(CONSTIFIED_ENUM_MODULE_REPR_NAME);
+
+                let constant = aster::AstBuilder::new()
+                    .item()
+                    .pub_()
+                    .const_(&*variant_name)
+                    .expr()
+                    .build(expr)
+                    .build(inside_module_type.clone());
+
+                let mut module_items = module_items.clone();
+                module_items.push(constant);
+
+                EnumBuilder::ModuleConsts {
+                    module_name,
+                    module_items,
+                }
+            }
         }
     }
 
@@ -2160,6 +2200,22 @@ impl<'a> EnumBuilder<'a> {
                 aster
             }
             EnumBuilder::Consts { aster, .. } => aster,
+            EnumBuilder::ModuleConsts { module_items, module_name, .. } => {
+                // Create module item with type and variant definitions
+                let module_item = P(ast::Item {
+                    ident: ast::Ident::from_str(module_name),
+                    attrs: vec![],
+                    id: ast::DUMMY_NODE_ID,
+                    node: ast::ItemKind::Mod(ast::Mod {
+                        inner: DUMMY_SP,
+                        items: module_items,
+                    }),
+                    vis: ast::Visibility::Public,
+                    span: DUMMY_SP,
+                });
+
+                module_item
+            }
         }
     }
 }
@@ -2225,7 +2281,10 @@ impl CodeGenerator for Enum {
                 .any(|v| ctx.options().bitfield_enums.matches(&v.name())))
         };
 
-        let is_constified_enum = {
+        let is_constified_enum_module = self.is_constified_enum_module(ctx, item);
+
+        let is_constified_enum =  {
+            is_constified_enum_module ||
             ctx.options().constified_enums.matches(&name) ||
             (enum_ty.name().is_none() &&
              self.variants()
@@ -2300,7 +2359,8 @@ impl CodeGenerator for Enum {
                                            &name,
                                            repr,
                                            is_bitfield,
-                                           is_constified_enum);
+                                           is_constified_enum,
+                                           is_constified_enum_module);
 
         // A map where we keep a value -> variant relation.
         let mut seen_values = HashMap::<_, String>::new();
diff --git a/src/ir/enum_ty.rs b/src/ir/enum_ty.rs
index e64354fb..3d326771 100644
--- a/src/ir/enum_ty.rs
+++ b/src/ir/enum_ty.rs
@@ -5,11 +5,14 @@ use super::item::Item;
 use super::ty::TypeKind;
 use clang;
 use ir::annotations::Annotations;
+use ir::item::ItemCanonicalName;
 use parse::{ClangItemParser, ParseError};
 
 /// An enum representing custom handling that can be given to a variant.
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum EnumVariantCustomBehavior {
+    /// This variant will be a module containing constants.
+    ModuleConstify,
     /// This variant will be constified, that is, forced to generate a constant.
     Constify,
     /// This variant will be hidden entirely from the resulting enum.
@@ -121,6 +124,18 @@ impl Enum {
         });
         Ok(Enum::new(repr, variants))
     }
+
+    // Whether the enum should be an constified enum module
+    pub fn is_constified_enum_module(&self, ctx: &BindgenContext, item: &Item) -> bool {
+        let name = item.canonical_name(ctx);
+        let enum_ty = item.expect_type();
+
+        ctx.options().constified_enum_modules.matches(&name) ||
+        (enum_ty.name().is_none() &&
+            self.variants()
+            .iter()
+            .any(|v| ctx.options().constified_enum_modules.matches(&v.name())))
+    }
 }
 
 /// A single enum variant, to be contained only in an enum.
diff --git a/src/ir/item.rs b/src/ir/item.rs
index 6c118f54..735b3390 100644
--- a/src/ir/item.rs
+++ b/src/ir/item.rs
@@ -1,5 +1,6 @@
 //! Bindgen's core intermediate representation type.
 
+use super::super::codegen::CONSTIFIED_ENUM_MODULE_REPR_NAME;
 use super::annotations::Annotations;
 use super::context::{BindgenContext, ItemId, PartialType};
 use super::derive::{CanDeriveCopy, CanDeriveDebug, CanDeriveDefault};
@@ -1444,6 +1445,15 @@ impl ItemCanonicalPath for Item {
                                       ctx: &BindgenContext)
                                       -> Vec<String> {
         let path = self.canonical_path(ctx);
+        if let super::item_kind::ItemKind::Type(ref type_) = self.kind {
+            if let &TypeKind::Enum(ref enum_) = type_.kind() {
+                if enum_.is_constified_enum_module(ctx, self) {
+                    // Type alias is inside a module
+                    return vec![path.last().unwrap().clone(),
+                                CONSTIFIED_ENUM_MODULE_REPR_NAME.into()];
+                }
+            }
+        }
         if ctx.options().enable_cxx_namespaces {
             return path;
         }
diff --git a/src/lib.rs b/src/lib.rs
index cd5cf8e1..2bcc21c0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -206,6 +206,16 @@ impl Builder {
             .count();
 
         self.options
+            .constified_enum_modules
+            .get_items()
+            .iter()
+            .map(|item| {
+                     output_vector.push("--constified-enum-module".into());
+                     output_vector.push(item.trim_left_matches("^").trim_right_matches("$").into());
+                 })
+            .count();
+
+        self.options
             .hidden_types
             .get_items()
             .iter()
@@ -562,8 +572,8 @@ impl Builder {
         self
     }
 
-    /// Mark the given enum (or set of enums, if using a pattern) as being
-    /// constant.
+    /// Mark the given enum (or set of enums, if using a pattern) as a set of
+    /// constants.
     ///
     /// This makes bindgen generate constants instead of enums. Regular
     /// expressions are supported.
@@ -572,6 +582,16 @@ impl Builder {
         self
     }
 
+    /// Mark the given enum (or set of enums, if using a pattern) as a set of
+    /// constants that should be put into a module.
+    ///
+    /// This makes bindgen generate a modules containing constants instead of
+    /// enums. Regular expressions are supported.
+    pub fn constified_enum_module<T: AsRef<str>>(mut self, arg: T) -> Builder {
+        self.options.constified_enum_modules.insert(arg);
+        self
+    }
+
     /// Add a string to prepend to the generated bindings. The string is passed
     /// through without any modification.
     pub fn raw_line<T: Into<String>>(mut self, arg: T) -> Builder {
@@ -813,6 +833,9 @@ pub struct BindgenOptions {
     /// The enum patterns to mark an enum as constant.
     pub constified_enums: RegexSet,
 
+    /// The enum patterns to mark an enum as a module of constants.
+    pub constified_enum_modules: RegexSet,
+
     /// Whether we should generate builtins or not.
     pub builtins: bool,
 
@@ -935,6 +958,7 @@ impl BindgenOptions {
         self.hidden_types.build();
         self.opaque_types.build();
         self.bitfield_enums.build();
+        self.constified_enum_modules.build();
         self.constified_enums.build();
     }
 }
@@ -949,6 +973,7 @@ impl Default for BindgenOptions {
             whitelisted_vars: Default::default(),
             bitfield_enums: Default::default(),
             constified_enums: Default::default(),
+            constified_enum_modules: Default::default(),
             builtins: false,
             links: vec![],
             emit_ast: false,
diff --git a/src/options.rs b/src/options.rs
index bbf9c0dd..96f49849 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -33,6 +33,15 @@ pub fn builder_from_flags<I>
                 .takes_value(true)
                 .multiple(true)
                 .number_of_values(1),
+            Arg::with_name("constified-enum-module")
+                .long("constified-enum-module")
+                .help("Mark any enum whose name matches <regex> as a module of \
+                       constants instead of an enumeration. This option \
+                       implies \"--constified-enum.\"")
+                .value_name("regex")
+                .takes_value(true)
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("blacklist-type")
                 .long("blacklist-type")
                 .help("Mark <type> as hidden.")
@@ -222,12 +231,17 @@ pub fn builder_from_flags<I>
         }
     }
 
-    if let Some(bitfields) = matches.values_of("constified-enum") {
-        for regex in bitfields {
+    if let Some(constifieds) = matches.values_of("constified-enum") {
+        for regex in constifieds {
             builder = builder.constified_enum(regex);
         }
     }
 
+    if let Some(constified_mods) = matches.values_of("constified-enum-module") {
+        for regex in constified_mods {
+            builder = builder.constified_enum_module(regex);
+        }
+    }
     if let Some(hidden_types) = matches.values_of("blacklist-type") {
         for ty in hidden_types {
             builder = builder.hide_type(ty);
diff --git a/tests/expectations/tests/constify-module-enums.rs b/tests/expectations/tests/constify-module-enums.rs
new file mode 100644
index 00000000..ca59236e
--- /dev/null
+++ b/tests/expectations/tests/constify-module-enums.rs
@@ -0,0 +1,35 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+pub mod foo {
+    pub type Type = ::std::os::raw::c_uint;
+    pub const THIS: Type = 0;
+    pub const SHOULD_BE: Type = 1;
+    pub const A_CONSTANT: Type = 2;
+}
+#[repr(C)]
+#[derive(Debug, Copy)]
+pub struct bar {
+    pub this_should_work: foo::Type,
+}
+#[test]
+fn bindgen_test_layout_bar() {
+    assert_eq!(::std::mem::size_of::<bar>() , 4usize , concat ! (
+               "Size of: " , stringify ! ( bar ) ));
+    assert_eq! (::std::mem::align_of::<bar>() , 4usize , concat ! (
+                "Alignment of " , stringify ! ( bar ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const bar ) ) . this_should_work as * const _
+                as usize } , 0usize , concat ! (
+                "Alignment of field: " , stringify ! ( bar ) , "::" ,
+                stringify ! ( this_should_work ) ));
+}
+impl Clone for bar {
+    fn clone(&self) -> Self { *self }
+}
+impl Default for bar {
+    fn default() -> Self { unsafe { ::std::mem::zeroed() } }
+}
diff --git a/tests/headers/constify-module-enums.h b/tests/headers/constify-module-enums.h
new file mode 100644
index 00000000..eb86844f
--- /dev/null
+++ b/tests/headers/constify-module-enums.h
@@ -0,0 +1,11 @@
+// bindgen-flags: --constified-enum-module foo
+
+enum foo {
+  THIS,
+  SHOULD_BE,
+  A_CONSTANT,
+};
+
+struct bar {
+  enum foo this_should_work;
+};