From 7db06f86efea90df387501735dea39681a82d4ae Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 19 Feb 2015 16:55:18 +0100 Subject: sys_core_fold: Fix non-tail-recursive list comprehensions 649d6e73 simplified opt_simple_let_2/6 a little bit too much, so that some list comprehensions in effect context were not properly tail-recursive. --- lib/compiler/src/sys_core_fold.erl | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'lib/compiler/src/sys_core_fold.erl') diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 7d1819ea15..2618f7adba 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -2288,10 +2288,17 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, Ctxt, Sub) -> %% No variables left. Body; {_,Arg,#c_literal{}} -> - %% Since the variable is not used in the body, we can rewrite the - %% let to a sequence: - %% let = Arg in Literal ==> seq Arg Literal - expr(#c_seq{arg=Arg,body=Body}, Ctxt, sub_new_preserve_types(Sub)); + E = case Ctxt of + effect -> + %% Throw away the literal body. + Arg; + value -> + %% Since the variable is not used in the body, we + %% can rewrite the let to a sequence. + %% let = Arg in Literal ==> seq Arg Literal + #c_seq{arg=Arg,body=Body} + end, + expr(E, Ctxt, sub_new_preserve_types(Sub)); {Vs,Arg,Body} -> %% If none of the variables are used in the body, we can %% rewrite the let to a sequence: -- cgit v1.2.3