Start taking into account non-fallible functions like core::mem::replace

2 files changed, 15 insertions, 5 deletions

diff --git a/compiler/ExtractBuiltin.ml b/compiler/ExtractBuiltin.ml
index 2e46b120..9cc7c226 100644
--- a/compiler/ExtractBuiltin.ml
+++ b/compiler/ExtractBuiltin.ml
@@ -29,6 +29,7 @@ module SimpleNameOrd = struct
 end
 
 module SimpleNameMap = Collections.MakeMap (SimpleNameOrd)
+module SimpleNameSet = Collections.MakeSet (SimpleNameOrd)
 
 (** Small utility to memoize some computations *)
 let mk_memoized (f : unit -> 'a) : unit -> 'a =
@@ -374,6 +375,13 @@ let mk_builtin_funs_map () =
 
 let builtin_funs_map = mk_memoized mk_builtin_funs_map
 
+let builtin_non_fallible_funs =
+  [ "alloc::boxed::Box::deref"; "alloc::boxed::Box::deref_mut" ]
+
+let builtin_non_fallible_funs_set =
+  SimpleNameSet.of_list
+    (List.map string_to_simple_name builtin_non_fallible_funs)
+
 type builtin_trait_decl_info = {
   rust_name : string;
   extract_name : string;
diff --git a/compiler/PureMicroPasses.ml b/compiler/PureMicroPasses.ml
index a326d19e..f3e6cbe2 100644
--- a/compiler/PureMicroPasses.ml
+++ b/compiler/PureMicroPasses.ml
@@ -1544,20 +1544,22 @@ let eliminate_box_functions (ctx : trans_ctx) (def : fun_decl) : fun_decl =
             | Fun (FromLlbc (FunId (Regular fid), _lp_id, rg_id)) -> (
                 (* Lookup the function name *)
                 let def = FunDeclId.Map.find fid ctx.fun_ctx.fun_decls in
-                match (Names.name_to_string def.name, rg_id) with
-                | "alloc::box::Boxed::deref", None ->
+                match
+                  (Names.name_no_disambiguators_to_string def.name, rg_id)
+                with
+                | "alloc::boxed::Box::deref", None ->
                     (* [Box::deref] forward is the identity *)
                     let arg, args = Collections.List.pop args in
                     mk_apps arg args
-                | "alloc::box::Boxed::deref", Some _ ->
+                | "alloc::boxed::Box::deref", Some _ ->
                     (* [Box::deref] backward is [()] (doesn't give back anything) *)
                     assert (args = []);
                     mk_unit_rvalue
-                | "alloc::box::Boxed::deref_mut", None ->
+                | "alloc::boxed::Box::deref_mut", None ->
                     (* [Box::deref_mut] forward is the identity *)
                     let arg, args = Collections.List.pop args in
                     mk_apps arg args
-                | "alloc::box::Boxed::deref_mut", Some _ ->
+                | "alloc::boxed::Box::deref_mut", Some _ ->
                     (* [Box::deref_mut] back is almost the identity:
                      * let box_deref_mut (x_init : t) (x_back : t) : t = x_back
                      * *)