ABI compatibility for struct/union function arguments passed by value.

The passing of struct/union arguments by value implemented in the verified
part of CompCert is not compatible with the ARM, PowerPC and x86 ABI.
Here we enrich the StructReturn source-to-source emulation pass
so that it implements the calling conventions defined in these ABIs.

Plus: for x86, implement the returning of struct/union results by value
in a way compatible with the ABI.

1 files changed, 6 insertions, 0 deletions

diff --git a/driver/Interp.ml b/driver/Interp.ml
index ab22cebb..57f252b0 100644
--- a/driver/Interp.ml
+++ b/driver/Interp.ml
@@ -380,6 +380,7 @@ let do_printf m fmt args =
 
 let (>>=) opt f = match opt with None -> None | Some arg -> f arg
 
+(*
 (* Like eventval_of_val, but accepts static globals as well *)
 
 let convert_external_arg ge v t =
@@ -399,6 +400,7 @@ let rec convert_external_args ge vl tl =
       convert_external_arg ge v1 t1 >>= fun e1 ->
       convert_external_args ge vl tl >>= fun el -> Some (e1 :: el)
   | _, _ -> None
+*)
 
 let do_external_function id sg ge w args m =
   match extern_atom id, args with
@@ -406,8 +408,12 @@ let do_external_function id sg ge w args m =
       extract_string m b ofs >>= fun fmt ->
       print_string (do_printf m fmt args');
       flush stdout;
+      Some(((w, [Event_syscall(id, [], EVint Int.zero)]), Vint Int.zero), m)
+(*
       convert_external_args ge args sg.sig_args >>= fun eargs ->
       Some(((w, [Event_syscall(id, eargs, EVint Int.zero)]), Vint Int.zero), m)
+*)
+
   | _ ->
       None