Initialization of union bit fields

Bit fields in unions were initialized like normal fields,
causing mismatch on the name of the field.

Also: added function Bitfields.carrier_field and refactored.

Patch by Bernhard Schommer.

Bug 23362

3 files changed, 45 insertions, 3 deletions

diff --git a/cparser/Bitfields.ml b/cparser/Bitfields.ml
index baf2b0ec..9ac9b61f 100644
--- a/cparser/Bitfields.ml
+++ b/cparser/Bitfields.ml
@@ -40,6 +40,10 @@ type bitfield_info =
      0 < pos + sz <= bitsizeof(int)
 *)
 
+let carrier_field bf =
+  { fld_name = bf.bf_carrier; fld_typ = bf.bf_carrier_typ;
+    fld_bitfield = None; fld_anonymous = false }
+
 (* Mapping (struct identifier, bitfield name) -> bitfield info *)
 
 let bitfield_table =
@@ -336,8 +340,7 @@ let rec transf_struct_init id fld_init_list =
       | Some bf ->
           let (el, rem') =
             pack_bitfield_init id bf.bf_carrier fld_init_list in
-          ({fld_name = bf.bf_carrier; fld_typ = bf.bf_carrier_typ;
-            fld_bitfield = None; fld_anonymous = false},
+          (carrier_field bf,
            Init_single {edesc = ECast(bf.bf_carrier_typ, or_expr_list el);
                         etyp = bf.bf_carrier_typ})
           :: transf_struct_init id rem'
@@ -504,7 +507,13 @@ and transf_init env i =
       let fld_init_list' =
         List.map (fun (f, i) -> (f, transf_init env i)) fld_init_list in
         Init_struct(id, transf_struct_init id fld_init_list')
-  | Init_union(id, fld, i) -> Init_union(id, fld, transf_init env i)
+  | Init_union(id, fld, i) ->
+      let i' = transf_init env i in
+      match is_bitfield id fld.fld_name with
+      | None ->
+          Init_union(id, fld, i')
+      | Some bf ->
+          Init_union(id, carrier_field bf, Init_single (bitfield_initializer bf i'))
 
 (* Declarations *)
 
diff --git a/test/regression/Results/bitfields9 b/test/regression/Results/bitfields9
index a1d0e9fd..e35c2414 100644
--- a/test/regression/Results/bitfields9
+++ b/test/regression/Results/bitfields9
@@ -1,10 +1,18 @@
 glob_s = { a = -12, b = 1 }
 glob_t = { c = 123, d = 1, e = -45 }
+glob_u_u = { u = -3 }
+glob_u_v = { v = 6 }
 loc_s = { a = 11, b = 2 }
 loc_t = { c = 11, d = 1, e = 2 }
+loc_u_u = { u = -5 }
+loc_u_v = { v = 3 }
 compound_s = { a = 2, b = 3 }
 compound_t = { c = 2, d = 1, e = -11 }
+compound_u = { u = 2 }
 loc_s = { a = 7, b = 2 }
 loc_t = { c = 7, d = 1, e = 50 }
+loc_u_u = { u = 7 }
+loc_u_v = { v = 2 }
 compound_s = { a = -14, b = 3 }
 compound_t = { c = 50, d = 1, e = -7 }
+compound_u = { u = 2 }
diff --git a/test/regression/bitfields9.c b/test/regression/bitfields9.c
index be87057b..54cc34ab 100644
--- a/test/regression/bitfields9.c
+++ b/test/regression/bitfields9.c
@@ -13,6 +13,11 @@ struct t {
   short e: 8;
 };
 
+union u {
+  int u: 4;
+  unsigned int v: 3;
+};
+
 void print_s(char * msg, struct s p)
 {
   printf("%s = { a = %d, b = %d }\n", msg, p.a, p.b);
@@ -23,25 +28,45 @@ void print_t(char * msg, struct t p)
   printf("%s = { c = %d, d = %d, e = %d }\n", msg, p.c, p.d, p.e);
 }
 
+void print_u_u(char * msg, union u p)
+{
+  printf("%s = { u = %d }\n", msg, p.u);
+}
+
+void print_u_v(char * msg, union u p)
+{
+  printf("%s = { v = %u }\n", msg, p.v);
+}
+
+
 /* Global initialization */
 struct s glob_s = { -12, 1 };
 struct t glob_t = { 123, 2, -45 };
+union u glob_u_u = { -3 };
+union u glob_u_v = { .v = 6 };
 
 /* Local initialization */
 void f(int x, int y, int z)
 {
   struct s loc_s = { x, y };
   struct t loc_t = { x, z, y };
+  union u loc_u_u = { .u = x };
+  union u loc_u_v = { .v = z };
   print_s("loc_s", loc_s);
   print_t("loc_t", loc_t);
+  print_u_u("loc_u_u", loc_u_u);
+  print_u_v("loc_u_v", loc_u_v);
   print_s("compound_s", (struct s) { y, x });
   print_t("compound_t", (struct t) { y, ~z, -x });
+  print_u_u("compound_u", (union u) { y });
 }
 
 int main()
 {
   print_s("glob_s", glob_s);
   print_t("glob_t", glob_t);
+  print_u_u("glob_u_u", glob_u_u);
+  print_u_v("glob_u_v", glob_u_v);
   f(11, 2, 3);
   f(7, 50, 2);
   return 0;