Clean up nomenclature in the Abi constants brigade. Purge magic GEP n…

…umbers in trans. Adjust obj_closure_rty (and its consumers) to be more explicit about the fact that it is a box.

src/boot/be/abi.ml

@@ -26,15 +26,15 @@ let frame_glue_fns_field_mark = 0;;
 let frame_glue_fns_field_drop = 1;;
 let frame_glue_fns_field_reloc = 2;;
 
-let box_rc_slot_field_refcnt = 0;;
-let box_rc_slot_field_body = 1;;
+let box_rc_field_refcnt = 0;;
+let box_rc_field_body = 1;;
 
-let box_gc_slot_alloc_base = (-3);;
-let box_gc_slot_field_prev = (-3);;
-let box_gc_slot_field_next = (-2);;
-let box_gc_slot_field_ctrl = (-1);;
-let box_gc_slot_field_refcnt = 0;;
-let box_gc_slot_field_body = 1;;
+let box_gc_alloc_base = (-3);;
+let box_gc_field_prev = (-3);;
+let box_gc_field_next = (-2);;
+let box_gc_field_ctrl = (-1);;
+let box_gc_field_refcnt = 0;;
+let box_gc_field_body = 1;;
 
 let box_rc_header_size = 1;;
 let box_gc_header_size = 4;;
@@ -45,13 +45,21 @@ let stk_field_valgrind_id = 0 + 1;;
 let stk_field_limit = stk_field_valgrind_id + 1;;
 let stk_field_data = stk_field_limit + 1;;
 
-let binding_size = 2;;
-let binding_field_item = 0;;
-let binding_field_binding = 1;;
+let obj_elt_vtbl = 0;;
+let obj_elt_body_box = 1;;
 
-let obj_elt_rc = 0;;
-let obj_elt_tydesc = 1;;
-let obj_elt_fields = 2;;
+let obj_body_elt_tydesc = 0;;
+let obj_body_elt_fields = 1;;
+
+let fn_elt_thunk = 0;;
+let fn_elt_closure = 1;;
+
+let closure_elt_rc = 0;;
+let closure_elt_target = 1;;
+let closure_elt_bound_args = 2;;
+
+let tag_elt_discriminant = 0;;
+let tag_elt_variant = 1;;
 
 let general_code_alignment = 16;;
 

src/boot/be/x86.ml

@@ -830,7 +830,7 @@ let sweep_gc_chain
     emit (Il.jmp Il.JE
             (codefix exit_jmp_fix));            (* if nonzero             *)
     mov (rc ecx)                                (* Load GC ctrl word      *)
-      (c (edi_n Abi.box_gc_slot_field_ctrl));
+      (c (edi_n Abi.box_gc_field_ctrl));
     mov (rc eax) (ro ecx);
     band (rc eax) (immi 1L);                    (* Extract mark to eax.   *)
     band                                        (* Clear mark in ecx.     *)
@@ -840,7 +840,7 @@ let sweep_gc_chain
     if clear_mark
     then
       mov                                       (* Write-back cleared.    *)
-        ((edi_n Abi.box_gc_slot_field_ctrl))
+        ((edi_n Abi.box_gc_field_ctrl))
         (ro ecx);
 
     emit (Il.cmp (ro eax) (immi 0L));
@@ -872,7 +872,7 @@ let sweep_gc_chain
 
     mark skip_jmp_fix;
     mov (rc edi)                                (* Advance down chain     *)
-      (c (edi_n Abi.box_gc_slot_field_next));
+      (c (edi_n Abi.box_gc_field_next));
     emit (Il.jmp Il.JMP
             (codefix repeat_jmp_fix));          (* loop                   *)
     mark exit_jmp_fix;

src/boot/llvm/lltrans.ml

@@ -453,15 +453,15 @@ let trans_crate
                 llbuilder :=
                   if_ptr_in_slot_not_null
                     (decr_refcnt_and_if_zero
-                       Abi.box_rc_slot_field_refcnt
+                       Abi.box_rc_field_refcnt
                        free_and_null_out_slot)
                     (!llbuilder)
 
             | MEM_rc_opaque ->
                 llbuilder :=
                   if_ptr_in_slot_not_null
                     (decr_refcnt_and_if_zero
-                       Abi.box_rc_slot_field_refcnt
+                       Abi.box_rc_field_refcnt
                        free_and_null_out_slot)
                     (!llbuilder)
 

src/boot/me/dwarf.ml

@@ -2019,7 +2019,7 @@ let dwarf_visitor
       let box_type t =
         let fix = new_fixup "box DIE" in
         let body_off =
-          word_sz_int * Abi.box_rc_slot_field_body
+          word_sz_int * Abi.box_rc_field_body
         in
           emit_die (DEF (fix, SEQ [|
                            uleb (get_abbrev_code abbrev_box_type);

src/boot/me/layout.ml

@@ -222,7 +222,7 @@ let layout_visitor
     let offset =
       let word_sz = cx.ctxt_abi.Abi.abi_word_sz in
       let word_n (n:int) = Int64.mul word_sz (Int64.of_int n) in
-        SIZE_fixed (word_n (Abi.box_rc_slot_field_body
+        SIZE_fixed (word_n (Abi.box_rc_field_body
                             + 1 (* the state tydesc. *)))
     in
       log cx "laying out object-state for node #%d at offset %s"

src/boot/me/semant.ml

@@ -1894,11 +1894,14 @@ let tydesc_rty (abi:Abi.abi) : Il.referent_ty =
 ;;
 
 let obj_closure_rty (abi:Abi.abi) : Il.referent_ty =
-  Il.StructTy [| word_rty abi;
-                 Il.ScalarTy (Il.AddrTy (tydesc_rty abi));
-                 word_rty abi (* A lie: it's opaque, but this permits
-                               * GEP'ing to it. *)
-              |]
+  Il.StructTy [|
+    word_rty abi;
+    Il.StructTy [|
+      Il.ScalarTy (Il.AddrTy (tydesc_rty abi));
+      word_rty abi (* A lie: it's opaque, but this permits
+                    * GEP'ing to it. *)
+    |]
+  |]
 ;;
 
 let rec referent_type (abi:Abi.abi) (t:Ast.ty) : Il.referent_ty =