From 03f79ba054b5509a05b164220f7d218d278298df Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Wed, 4 Feb 2015 08:05:09 +0100 Subject: Clean up evaluation of setelement/3 The 'try' ... 'catch' is problematic. Firstly, if no optimization is possible, an exception will always be thrown. Secondly, bugs in the code will go unnoticed. --- lib/compiler/src/sys_core_fold.erl | 40 +++++++++++++++++++++----------------- 1 file changed, 22 insertions(+), 18 deletions(-) (limited to 'lib/compiler/src') diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index b9ce6476c3..8299c6a415 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1014,28 +1014,32 @@ eval_is_record(Call, _, _, _, _) -> Call. %% eval_setelement(Call, Pos, Tuple, NewVal) -> Core. %% Evaluates setelement/3 if position Pos is an integer -%% the shape of the tuple Tuple is known. +%% and the shape of the tuple Tuple is known. %% -eval_setelement(Call, Pos, Tuple, NewVal) -> - try - eval_setelement_1(Pos, Tuple, NewVal) - catch - error:_ -> - Call - end. - -eval_setelement_1(#c_literal{val=Pos}, #c_tuple{anno=A,es=Es}, NewVal) - when is_integer(Pos) -> - ann_c_tuple(A, eval_setelement_2(Pos, Es, NewVal)); -eval_setelement_1(#c_literal{val=Pos}, #c_literal{anno=A,val=Es0}, NewVal) +eval_setelement(Call, #c_literal{val=Pos}, Tuple, NewVal) when is_integer(Pos) -> - Es = [#c_literal{anno=A,val=E} || E <- tuple_to_list(Es0)], - ann_c_tuple(A, eval_setelement_2(Pos, Es, NewVal)). + case cerl:is_data(Tuple) of + false -> + Call; + true -> + Es0 = case cerl:is_c_tuple(Tuple) of + false -> []; + true -> cerl:tuple_es(Tuple) + end, + if + 1 =< Pos, Pos =< length(Es0) -> + Es = eval_setelement_1(Pos, Es0, NewVal), + cerl:update_c_tuple(Tuple, Es); + true -> + eval_failure(Call, badarg) + end + end; +eval_setelement(Call, _, _, _) -> Call. -eval_setelement_2(1, [_|T], NewVal) -> +eval_setelement_1(1, [_|T], NewVal) -> [NewVal|T]; -eval_setelement_2(Pos, [H|T], NewVal) when Pos > 1 -> - [H|eval_setelement_2(Pos-1, T, NewVal)]. +eval_setelement_1(Pos, [H|T], NewVal) when Pos > 1 -> + [H|eval_setelement_1(Pos-1, T, NewVal)]. %% eval_failure(Call, Reason) -> Core. %% Warn for a call that will fail and replace the call with -- cgit v1.2.3