Flow typing and l-expression changes for ASL parser

1. Experiment with allowing some flow typing on mutable variables for
translating ASL in a more idiomatic way. I realise after updating some
of the test cases that this could have some problematic side effects
for lem translation, where mutable variables are translated into
monadic code. We'd need to ensure that whatever flow typing happens
for mutable variables also works for monadic code, including within
transformed loops. If this doesn't work out some of these changes may
need to be reverted.

2. Make the type inference for l-expressions a bit smarter. Splits the
type checking rules for l-expressions into a inference part and a
checking part like the other bi-directional rules. Should not be able
to type check slightly more l-expresions, such as nested vector slices
that may not have checked previously.

The l-expression rules for vector patterns should be simpler now, but
they are also more strict about bounds checking. Previously the bounds
checks were derived from the corresponding operations that would
appear on the RHS (i.e. LEXP_vector would get it's check from
vector_access). This meant that the l-expression bounds checks could
be weakend by weakening the checks on those operations. Now this is no
longer possible, there is a -no_lexp_bounds_check option which turns
of bounds checking in l-expressions. Currently this is on for the
generated ARM spec, but this should only be temporary.

3. Add a LEXP_vector_concat which mirrors P_vector_concat except in
l-expressions. Previously there was a hack that overloaded LEXP_tup
for this to translate some ASL patterns, but that was fairly
ugly. Adapt the rewriter and other parts of the code to handle
this. The rewriter for lexp tuple vector assignments is now a rewriter
for vector concat assignments.

4. Include a newly generated version of aarch64_no_vector

5. Update the Ocaml test suite to use builtins in lib/

1 files changed, 10 insertions, 1 deletions

diff --git a/src/rewriter.ml b/src/rewriter.ml
index 203e8a58..82e3ab05 100644
--- a/src/rewriter.ml
+++ b/src/rewriter.ml
@@ -197,6 +197,8 @@ let fix_eff_lexp (LEXP_aux (lexp,((l,_) as annot))) = match snd annot with
     | LEXP_memory (_,es) -> union_eff_exps es
     | LEXP_tup les ->
       List.fold_left (fun eff le -> union_effects eff (effect_of_lexp le)) no_effect les
+    | LEXP_vector_concat les ->
+      List.fold_left (fun eff le -> union_effects eff (effect_of_lexp le)) no_effect les
     | LEXP_vector (lexp,e) -> union_effects (effect_of_lexp lexp) (effect_of e)
     | LEXP_vector_range (lexp,e1,e2) ->
       union_effects (effect_of_lexp lexp)
@@ -384,6 +386,7 @@ let rewrite_lexp rewriters (LEXP_aux(lexp,(l,annot))) =
     rewrap (LEXP_vector_range (rewriters.rewrite_lexp rewriters lexp,
                                rewriters.rewrite_exp rewriters exp1,
                                rewriters.rewrite_exp rewriters exp2))
+  | LEXP_vector_concat lexps -> rewrap (LEXP_vector_concat (List.map (rewriters.rewrite_lexp rewriters) lexps))
   | LEXP_field (lexp,id) -> rewrap (LEXP_field (rewriters.rewrite_lexp rewriters lexp,id))
 
 let rewrite_fun rewriters (FD_aux (FD_function(recopt,tannotopt,effectopt,funcls),(l,fdannot))) = 
@@ -556,6 +559,7 @@ type ('a,'exp,'exp_aux,'lexp,'lexp_aux,'fexp,'fexp_aux,'fexps,'fexps_aux,
   ; lEXP_tup                 : 'lexp list -> 'lexp_aux
   ; lEXP_vector              : 'lexp * 'exp -> 'lexp_aux
   ; lEXP_vector_range        : 'lexp * 'exp * 'exp -> 'lexp_aux
+  ; lEXP_vector_concat       : 'lexp list -> 'lexp_aux
   ; lEXP_field               : 'lexp * id -> 'lexp_aux
   ; lEXP_aux                 : 'lexp_aux * 'a annot -> 'lexp
   ; fE_Fexp                  : id * 'exp -> 'fexp_aux
@@ -635,7 +639,8 @@ and fold_lexp_aux alg = function
   | LEXP_vector (lexp,e) -> alg.lEXP_vector (fold_lexp alg lexp, fold_exp alg e)
   | LEXP_vector_range (lexp,e1,e2) ->
      alg.lEXP_vector_range (fold_lexp alg lexp, fold_exp alg e1, fold_exp alg e2)
- | LEXP_field (lexp,id) -> alg.lEXP_field (fold_lexp alg lexp, id)
+  | LEXP_vector_concat les -> alg.lEXP_vector_concat (List.map (fold_lexp alg) les)
+  | LEXP_field (lexp,id) -> alg.lEXP_field (fold_lexp alg lexp, id)
 and fold_lexp alg (LEXP_aux (lexp_aux,annot)) =
   alg.lEXP_aux (fold_lexp_aux alg lexp_aux, annot)
 and fold_fexp_aux alg (FE_Fexp (id,e)) = alg.fE_Fexp (id, fold_exp alg e)
@@ -706,6 +711,7 @@ let id_exp_alg =
   ; lEXP_tup = (fun tups -> LEXP_tup tups)
   ; lEXP_vector = (fun (lexp,e2) -> LEXP_vector (lexp,e2))
   ; lEXP_vector_range = (fun (lexp,e2,e3) -> LEXP_vector_range (lexp,e2,e3))
+  ; lEXP_vector_concat = (fun lexps -> LEXP_vector_concat lexps)
   ; lEXP_field = (fun (lexp,id) -> LEXP_field (lexp,id))
   ; lEXP_aux = (fun (lexp,annot) -> LEXP_aux (lexp,annot))
   ; fE_Fexp = (fun (id,e) -> FE_Fexp (id,e))
@@ -813,6 +819,9 @@ let compute_exp_alg bot join =
   ; lEXP_vector = (fun ((vl,lexp),(v2,e2)) -> (join vl v2, LEXP_vector (lexp,e2)))
   ; lEXP_vector_range = (fun ((vl,lexp),(v2,e2),(v3,e3)) ->
     (join_list [vl;v2;v3], LEXP_vector_range (lexp,e2,e3)))
+  ; lEXP_vector_concat = (fun ls ->
+    let (vs,ls) = List.split ls in
+    (join_list vs, LEXP_vector_concat ls))
   ; lEXP_field = (fun ((vl,lexp),id) -> (vl, LEXP_field (lexp,id)))
   ; lEXP_aux = (fun ((vl,lexp),annot) -> (vl, LEXP_aux (lexp,annot)))
   ; fE_Fexp = (fun (id,(v,e)) -> (v, FE_Fexp (id,e)))