From 43a91c5e461e3fbec924e332f42fd69b81be34b2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 22 Mar 2018 12:38:39 +0100 Subject: cerl_inline: Fix a name capture bug The way variables created by make_template() are used, it is necessary that the names are unique in the entire function. This has not happened to cause any problems in the past because all other compiler passes created atom variable names, not integer variable names. If other passes start to create integer variable names, this bug is exposed. --- lib/compiler/src/cerl_inline.erl | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'lib/compiler/src') diff --git a/lib/compiler/src/cerl_inline.erl b/lib/compiler/src/cerl_inline.erl index f5afa75b16..caff47dbcb 100644 --- a/lib/compiler/src/cerl_inline.erl +++ b/lib/compiler/src/cerl_inline.erl @@ -1822,6 +1822,14 @@ new_var(Env) -> Name = env__new_vname(Env), c_var(Name). +%% The way a template variable is used makes it necessary +%% to make sure that it is unique in the entire function. +%% Therefore, template variables are atoms with the prefix "@i". + +new_template_var(Env) -> + Name = env__new_tname(Env), + c_var(Name). + residualize_var(R, S) -> S1 = count_size(weight(var), S), {ref_to_var(R), st__set_var_referenced(R#ref.loc, S1)}. @@ -2183,7 +2191,7 @@ make_template(E, Vs0, Env0) -> T = make_data_skel(data_type(E), Ts), E1 = update_data(E, data_type(E), [hd(get_ann(T)) || T <- Ts]), - V = new_var(Env1), + V = new_template_var(Env1), Env2 = env__bind(var_name(V), E1, Env1), {set_ann(T, [V]), [V | Vs1], Env2}; false -> @@ -2198,7 +2206,7 @@ make_template(E, Vs0, Env0) -> Env2 = env__bind(V, E1, Env1), {T, Vs1, Env2}; _ -> - V = new_var(Env0), + V = new_template_var(Env0), Env1 = env__bind(var_name(V), E, Env0), {set_ann(V, [V]), [V | Vs0], Env1} end @@ -2564,6 +2572,11 @@ env__is_defined(Key, Env) -> env__new_vname(Env) -> rec_env:new_key(Env). +env__new_tname(Env) -> + rec_env:new_key(fun(I) -> + list_to_atom("@i"++integer_to_list(I)) + end, Env). + env__new_fname(A, N, Env) -> rec_env:new_key(fun (X) -> S = integer_to_list(X), -- cgit v1.2.3