aboutsummaryrefslogtreecommitdiffstats
path: root/lib/compiler/test
diff options
context:
space:
mode:
Diffstat (limited to 'lib/compiler/test')
-rw-r--r--lib/compiler/test/core_fold_SUITE.erl32
1 files changed, 30 insertions, 2 deletions
diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl
index afb8fa5599..8151dc1b16 100644
--- a/lib/compiler/test/core_fold_SUITE.erl
+++ b/lib/compiler/test/core_fold_SUITE.erl
@@ -22,7 +22,8 @@
init_per_group/2,end_per_group/2,
t_element/1,setelement/1,t_length/1,append/1,t_apply/1,bifs/1,
eq/1,nested_call_in_case/1,guard_try_catch/1,coverage/1,
- unused_multiple_values_error/1,unused_multiple_values/1]).
+ unused_multiple_values_error/1,unused_multiple_values/1,
+ multiple_aliases/1]).
-export([foo/0,foo/1,foo/2,foo/3]).
@@ -38,7 +39,8 @@ groups() ->
[{p,test_lib:parallel(),
[t_element,setelement,t_length,append,t_apply,bifs,
eq,nested_call_in_case,guard_try_catch,coverage,
- unused_multiple_values_error,unused_multiple_values]}].
+ unused_multiple_values_error,unused_multiple_values,
+ multiple_aliases]}].
init_per_suite(Config) ->
@@ -337,4 +339,30 @@ do_something(I) ->
[I|get(unused_multiple_values)]),
I.
+
+%% Make sure that multiple aliases does not cause
+%% the case expression to be evaluated twice.
+multiple_aliases(Config) when is_list(Config) ->
+ do_ma(fun() ->
+ X = Y = run_once(),
+ {X,Y}
+ end, {ok,ok}),
+ do_ma(fun() ->
+ case {true,run_once()} of
+ {true=A=B,ok=X=Y} ->
+ {A,B,X,Y}
+ end
+ end, {true,true,ok,ok}),
+ ok.
+
+do_ma(Fun, Expected) when is_function(Fun, 0) ->
+ Expected = Fun(),
+ ran_once = erase(run_once),
+ ok.
+
+run_once() ->
+ undefined = put(run_once, ran_once),
+ ok.
+
+
id(I) -> I.