diff options
| author | Thomas Bauereiss | 2018-05-17 16:00:31 +0100 |
|---|---|---|
| committer | Thomas Bauereiss | 2018-05-18 20:11:24 +0100 |
| commit | 5e363d23bc54b3970a9e1f6fbea77bbb8459df6f (patch) | |
| tree | ac6bd6ea9d6eaa4db3057788225b541cf34af8a6 /src | |
| parent | 96efc58a8c8a6f61988d42a552dceb167d4f603d (diff) | |
Fix bug in rewriting variable updates
Diffstat (limited to 'src')
| -rw-r--r-- | src/rewrites.ml | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/rewrites.ml b/src/rewrites.ml index b59a248e..dff8e3e5 100644 --- a/src/rewrites.ml +++ b/src/rewrites.ml @@ -2911,7 +2911,8 @@ let rec rewrite_var_updates ((E_aux (expaux,((l,_) as annot))) as exp) = | E_for(id,exp1,exp2,exp3,order,exp4) -> (* Translate for loops into calls to one of the foreach combinators. The loop body becomes a function of the loop variable and any - mutable local variables that are updated inside the loop. + mutable local variables that are updated inside the loop and + are used after or within the loop. Since the foreach* combinators are higher-order functions, they cannot be represented faithfully in the AST. The following code abuses the parameters of an E_app node, embedding the loop body @@ -2920,7 +2921,7 @@ let rec rewrite_var_updates ((E_aux (expaux,((l,_) as annot))) as exp) = function and passed to foreach*. *) let vars, varpats = find_updated_vars exp4 - |> IdSet.inter used_vars + |> IdSet.inter (IdSet.union used_vars (find_used_vars full_exp)) |> mk_var_exps_pats pl env in let exp4 = rewrite_var_updates (add_vars overwrite exp4 vars) in @@ -2976,9 +2977,11 @@ let rec rewrite_var_updates ((E_aux (expaux,((l,_) as annot))) as exp) = let v = fix_eff_exp (annot_exp (E_app (mk_id "foreach", [exp1; exp2; exp3; ord_exp; tuple_exp vars; guarded_body])) el env (typ_of body)) in Added_vars (v, tuple_pat (if overwrite then varpats else pat :: varpats)) | E_loop(loop,cond,body) -> + (* Find variables that might be updated in the loop body and are used + either after or within the loop. *) let vars, varpats = find_updated_vars body - |> IdSet.inter used_vars + |> IdSet.inter (IdSet.union used_vars (find_used_vars full_exp)) |> mk_var_exps_pats pl env in let body = rewrite_var_updates (add_vars overwrite body vars) in |