1 files changed, 51 insertions, 6 deletions

diff --git a/cparser/Cutil.ml b/cparser/Cutil.ml
index f5d5c425..2334966c 100644
--- a/cparser/Cutil.ml
+++ b/cparser/Cutil.ml
@@ -37,6 +37,15 @@ module IdentMap = Map.Make(Ident)
 
 (* Operations on attributes *)
 
+(* Normalize the name of an attribute, removing starting and trailing '__' *)
+
+let re_normalize_attrname = Str.regexp "^__\\(.*\\)__$"
+
+let normalize_attrname a =
+  if Str.string_match re_normalize_attrname a 0
+  then Str.matched_group 1 a
+  else a
+
 (* Lists of attributes are kept sorted in increasing order *)
 
 let rec add_attributes (al1: attributes) (al2: attributes) =
@@ -83,18 +92,35 @@ let rec remove_custom_attributes (names: string list)  (al: attributes) =
   | a :: tl ->
       a :: remove_custom_attributes names tl
 
+(* Classification of attributes *)
+
+type attribute_class =
+  | Attr_name           (* Attribute applies to the names being declared  *)
+  | Attr_type           (* Attribute applies to types *)
+  | Attr_struct         (* Attribute applies to struct, union and enum *)
+  | Attr_function       (* Attribute applies to function types and decls *)
+  | Attr_unknown        (* Unknown attribute *)
+      
+let attr_class : (string, attribute_class) Hashtbl.t = Hashtbl.create 32
+
+let declare_attribute name cls =
+  Hashtbl.replace attr_class (normalize_attrname name) cls
+
+let declare_attributes l =
+  List.iter (fun (n,c) -> declare_attribute n c) l
+
+let class_of_attribute = function
+  | AConst | AVolatile | ARestrict | AAlignas _ -> Attr_type
+  | Attr(name, args) ->
+      try Hashtbl.find attr_class (normalize_attrname name)
+      with Not_found -> Attr_unknown
+
 (* Is an attribute a ISO C standard attribute? *)
 
 let attr_is_standard = function
   | AConst | AVolatile | ARestrict -> true
   | AAlignas _ | Attr _ -> false
 
-(* Is an attribute type-related (true) or variable-related (false)? *)
-
-let attr_is_type_related = function
-  | Attr(("packed" | "__packed__"), _) -> true
-  | _ -> false
-
 (* Is an attribute applicable to a whole array (true) or only to
    array elements (false)? *)
 
@@ -533,6 +559,25 @@ let sizeof_struct env members =
       end
   in sizeof_rec 0 members
 
+(* Compute the offset of a struct member *)
+let offsetof env ty field =
+  let rec sub acc name = function
+    | [] -> List.rev acc
+    | m::rem -> if m.fld_name = name then
+        List.rev acc
+      else
+        sub (m::acc) name rem in
+  match unroll env ty with
+    | TStruct (id,_) ->
+      let str = Env.find_struct env id in
+      let pre = sub [] field.fld_name str.ci_members in
+      begin match sizeof_struct env pre, alignof env field.fld_typ with
+      | Some s, Some a ->
+        align s a
+      | _ -> assert false end
+    | TUnion _ -> 0
+    | _ -> assert false
+
 (* Simplified version to compute offsets on structs without bitfields *)
 let struct_layout env members =
   let rec struct_layout_rec mem ofs = function