From 696f47b64c8ad5da71cbffd8fecf0f3bae1e7466 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 26 Oct 2017 12:57:24 +0200 Subject: Correct erlang:is_builtin/3 for apply/2 and yield/0 erlang:is_builtin(erlang, M, F) returns false for apply/2 and yield/0. The documentation for erlang:is_builtin/3 says that it returns true for BIFs that are implemented in C. apply/2 and yield/0 are implemented in C (as BEAM instructions), and therefore the correct return value is true. Also see a similar argument that was made for apply/3 in the past: http://erlang.org/pipermail/erlang-bugs/2015-October/005101.html https://bugs.erlang.org/browse/ERL-500 --- erts/emulator/test/bif_SUITE.erl | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'erts/emulator/test/bif_SUITE.erl') diff --git a/erts/emulator/test/bif_SUITE.erl b/erts/emulator/test/bif_SUITE.erl index 146c37b118..e1b42e5d85 100644 --- a/erts/emulator/test/bif_SUITE.erl +++ b/erts/emulator/test/bif_SUITE.erl @@ -781,14 +781,20 @@ is_builtin(_Config) -> {F,A} <- M:module_info(exports)], Exp = ordsets:from_list(Exp0), - %% erlang:apply/3 is considered to be built-in, but is not - %% implemented as other BIFs. + %% Built-ins implemented as special instructions. + Instructions = [{erlang,apply,2},{erlang,apply,3},{erlang,yield,0}], - Builtins0 = [{erlang,apply,3}|erlang:system_info(snifs)], + Builtins0 = Instructions ++ erlang:system_info(snifs), Builtins = ordsets:from_list(Builtins0), - NotBuiltin = ordsets:subtract(Exp, Builtins), - _ = [true = erlang:is_builtin(M, F, A) || {M,F,A} <- Builtins], - _ = [false = erlang:is_builtin(M, F, A) || {M,F,A} <- NotBuiltin], + + Fakes = [{M,F,42} || {M,F,_} <- Instructions], + All = ordsets:from_list(Fakes ++ Exp), + NotBuiltin = ordsets:subtract(All, Builtins), + + _ = [{true,_} = {erlang:is_builtin(M, F, A),MFA} || + {M,F,A}=MFA <- Builtins], + _ = [{false,_} = {erlang:is_builtin(M, F, A),MFA} || + {M,F,A}=MFA <- NotBuiltin], ok. -- cgit v1.2.3