%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1999-2011. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(code_SUITE).
-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1,
init_per_group/2,end_per_group/2,
versions/1,new_binary_types/1,
t_check_process_code/1,t_check_old_code/1,
t_check_process_code_ets/1,
external_fun/1,get_chunk/1,module_md5/1,make_stub/1,
make_stub_many_funs/1,constant_pools/1,constant_refc_binaries/1,
false_dependency/1,coverage/1,fun_confusion/1]).
-define(line_trace, 1).
-include_lib("test_server/include/test_server.hrl").
suite() -> [{ct_hooks,[ts_install_cth]}].
all() ->
[versions, new_binary_types, t_check_process_code,
t_check_process_code_ets, t_check_old_code, external_fun, get_chunk,
module_md5, make_stub, make_stub_many_funs,
constant_pools, constant_refc_binaries, false_dependency,
coverage, fun_confusion].
groups() ->
[].
init_per_suite(Config) ->
erts_debug:set_internal_state(available_internal_state, true),
Config.
end_per_suite(_Config) ->
catch erts_debug:set_internal_state(available_internal_state, false),
ok.
init_per_group(_GroupName, Config) ->
Config.
end_per_group(_GroupName, Config) ->
Config.
%% Make sure that only two versions of a module can be loaded.
versions(Config) when is_list(Config) ->
V1 = compile_version(1, Config),
V2 = compile_version(2, Config),
V3 = compile_version(3, Config),
{ok,P1,1} = load_version(V1, 1),
{ok,P2,2} = load_version(V2, 2),
{error,not_purged} = load_version(V2, 2),
{error,not_purged} = load_version(V3, 3),
1 = check_version(P1),
2 = check_version(P2),
2 = versions:version(),
%% Kill processes, unload code.
P1 ! P2 ! done,
_ = monitor(process, P1),
_ = monitor(process, P2),
receive
{'DOWN',_,process,P1,normal} -> ok
end,
receive
{'DOWN',_,process,P2,normal} -> ok
end,
true = erlang:purge_module(versions),
true = erlang:delete_module(versions),
true = erlang:purge_module(versions),
ok.
compile_version(Version, Config) ->
Data = ?config(data_dir, Config),
File = filename:join(Data, "versions"),
{ok,versions,Bin} = compile:file(File, [{d,'VERSION',Version},
binary,report]),
Bin.
load_version(Code, Ver) ->
case erlang:load_module(versions, Code) of
{module,versions} ->
Pid = spawn_link(versions, loop, []),
Ver = versions:version(),
Ver = check_version(Pid),
{ok,Pid,Ver};
Error ->
Error
end.
check_version(Pid) ->
Pid ! {self(),version},
receive
{Pid,version,Version} ->
Version
end.
new_binary_types(Config) when is_list(Config) ->
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "my_code_test"),
?line {ok,my_code_test,Bin} = compile:file(File, [binary]),
?line {module,my_code_test} = erlang:load_module(my_code_test,
make_sub_binary(Bin)),
?line true = erlang:delete_module(my_code_test),
?line true = erlang:purge_module(my_code_test),
?line {module,my_code_test} = erlang:load_module(my_code_test,
make_unaligned_sub_binary(Bin)),
?line true = erlang:delete_module(my_code_test),
?line true = erlang:purge_module(my_code_test),
%% Try heap binaries and bad binaries.
?line {error,badfile} = erlang:load_module(my_code_test, <<1,2>>),
?line {error,badfile} = erlang:load_module(my_code_test,
make_sub_binary(<<1,2>>)),
?line {error,badfile} = erlang:load_module(my_code_test,
make_unaligned_sub_binary(<<1,2>>)),
?line {'EXIT',{badarg,_}} = (catch erlang:load_module(my_code_test,
bit_sized_binary(Bin))),
ok.
t_check_process_code(Config) when is_list(Config) ->
?line Priv = ?config(priv_dir, Config),
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "my_code_test"),
?line Code = filename:join(Priv, "my_code_test"),
?line {ok,my_code_test} = c:c(File, [{outdir,Priv}]),
?line MyFun = fun(X, Y) -> X + Y end, %Confuse things.
?line F = my_code_test:make_fun(42),
?line 2 = fun_refc(F),
?line MyFun2 = fun(X, Y) -> X * Y end, %Confuse things.
?line 44 = F(2),
%% Delete the module and call the fun again.
?line true = erlang:delete_module(my_code_test),
?line 2 = fun_refc(F),
?line 45 = F(3),
?line {'EXIT',{undef,_}} = (catch my_code_test:make_fun(33)),
%% The fun should still be there, preventing purge.
?line true = erlang:check_process_code(self(), my_code_test),
gc(),
gc(), %Place funs on the old heap.
?line true = erlang:check_process_code(self(), my_code_test),
%% Using the funs here guarantees that they will not be prematurely garbed.
?line 48 = F(6),
?line 3 = MyFun(1, 2),
?line 12 = MyFun2(3, 4),
%% Kill all funs.
t_check_process_code1(Code, []).
%% The real fun was killed, but we have some fakes which look similar.
t_check_process_code1(Code, Fakes) ->
?line MyFun = fun(X, Y) -> X + Y + 1 end, %Confuse things.
?line false = erlang:check_process_code(self(), my_code_test),
?line 4 = MyFun(1, 2),
t_check_process_code2(Code, Fakes).
t_check_process_code2(Code, _) ->
?line false = erlang:check_process_code(self(), my_code_test),
?line true = erlang:purge_module(my_code_test),
%% In the next test we will load the same module twice.
?line {module,my_code_test} = code:load_abs(Code),
?line F = my_code_test:make_fun(37),
?line 2 = fun_refc(F),
?line false = erlang:check_process_code(self(), my_code_test),
?line {module,my_code_test} = code:load_abs(Code),
?line 2 = fun_refc(F),
%% Still false because the fun with the same identify is found
%% in the current code.
?line false = erlang:check_process_code(self(), my_code_test),
%% Some fake funs in the same module should not do any difference.
?line false = erlang:check_process_code(self(), my_code_test),
38 = F(1),
t_check_process_code3(Code, F, []).
t_check_process_code3(Code, F, Fakes) ->
Pid = spawn_link(fun() -> body(F, Fakes) end),
?line true = erlang:purge_module(my_code_test),
?line false = erlang:check_process_code(self(), my_code_test),
?line false = erlang:check_process_code(Pid, my_code_test),
?line true = erlang:delete_module(my_code_test),
?line true = erlang:check_process_code(self(), my_code_test),
?line true = erlang:check_process_code(Pid, my_code_test),
39 = F(2),
t_check_process_code4(Code, Pid).
t_check_process_code4(_Code, Pid) ->
Pid ! drop_funs,
receive after 1 -> ok end,
?line false = erlang:check_process_code(Pid, my_code_test),
ok.
body(F, Fakes) ->
receive
jog ->
40 = F(3),
erlang:garbage_collect(),
body(F, Fakes);
drop_funs ->
dropped_body()
end.
dropped_body() ->
receive
X -> exit(X)
end.
gc() ->
erlang:garbage_collect(),
gc1().
gc1() -> ok.
t_check_process_code_ets(doc) ->
"Test check_process_code/2 in combination with a fun obtained from an ets table.";
t_check_process_code_ets(Config) when is_list(Config) ->
case test_server:is_native(?MODULE) of
true ->
{skip,"Native code"};
false ->
do_check_process_code_ets(Config)
end.
do_check_process_code_ets(Config) ->
?line Priv = ?config(priv_dir, Config),
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "my_code_test"),
?line erlang:purge_module(my_code_test),
?line erlang:delete_module(my_code_test),
?line {ok,my_code_test} = c:c(File, [{outdir,Priv}]),
?line T = ets:new(my_code_test, []),
?line ets:insert(T, {7,my_code_test:make_fun(107)}),
?line ets:insert(T, {8,my_code_test:make_fun(108)}),
?line erlang:delete_module(my_code_test),
?line false = erlang:check_process_code(self(), my_code_test),
Body = fun() ->
[{7,F1}] = ets:lookup(T, 7),
[{8,F2}] = ets:lookup(T, 8),
IdleLoop = fun() -> receive _X -> ok end end,
RecLoop = fun(Again) ->
receive
call -> 110 = F1(3),
100 = F2(-8),
Again(Again);
{drop_funs,To} ->
To ! funs_dropped,
IdleLoop()
end
end,
true = erlang:check_process_code(self(), my_code_test),
RecLoop(RecLoop)
end,
?line Pid = spawn_link(Body),
receive after 1 -> ok end,
?line true = erlang:check_process_code(Pid, my_code_test),
Pid ! call,
Pid ! {drop_funs,self()},
receive
funs_dropped -> ok;
Other -> ?t:fail({unexpected,Other})
after 10000 ->
?line ?t:fail(no_funs_dropped_answer)
end,
?line false = erlang:check_process_code(Pid, my_code_test),
ok.
fun_refc(F) ->
{refc,Count} = erlang:fun_info(F, refc),
Count.
%% Test the erlang:check_old_code/1 BIF.
t_check_old_code(Config) when is_list(Config) ->
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "my_code_test"),
?line erlang:purge_module(my_code_test),
?line erlang:delete_module(my_code_test),
?line catch erlang:purge_module(my_code_test),
?line false = erlang:check_old_code(my_code_test),
?line {ok,my_code_test,Code} = compile:file(File, [binary]),
?line {module,my_code_test} = code:load_binary(my_code_test, File, Code),
?line false = erlang:check_old_code(my_code_test),
?line {module,my_code_test} = code:load_binary(my_code_test, File, Code),
?line true = erlang:check_old_code(my_code_test),
?line true = erlang:purge_module(my_code_test),
?line true = erlang:delete_module(my_code_test),
?line true = erlang:purge_module(my_code_test),
?line {'EXIT',_} = (catch erlang:check_old_code([])),
ok.
external_fun(Config) when is_list(Config) ->
?line false = erlang:function_exported(another_code_test, x, 1),
AnotherCodeTest = id(another_code_test),
ExtFun = fun AnotherCodeTest:x/1,
?line {'EXIT',{undef,_}} = (catch ExtFun(answer)),
?line false = erlang:function_exported(another_code_test, x, 1),
?line false = lists:member(another_code_test, erlang:loaded()),
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "another_code_test"),
?line {ok,another_code_test,Code} = compile:file(File, [binary,report]),
?line {module,another_code_test} = erlang:load_module(another_code_test, Code),
?line 42 = ExtFun(answer),
ok.
get_chunk(Config) when is_list(Config) ->
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "my_code_test"),
?line {ok,my_code_test,Code} = compile:file(File, [binary]),
%% Should work.
?line Chunk = get_chunk_ok("Atom", Code),
?line Chunk = get_chunk_ok("Atom", make_sub_binary(Code)),
?line Chunk = get_chunk_ok("Atom", make_unaligned_sub_binary(Code)),
%% Should fail.
?line {'EXIT',{badarg,_}} = (catch code:get_chunk(bit_sized_binary(Code), "Atom")),
?line {'EXIT',{badarg,_}} = (catch code:get_chunk(Code, "bad chunk id")),
%% Invalid beam code or missing chunk should return 'undefined'.
?line undefined = code:get_chunk(<<"not a beam module">>, "Atom"),
?line undefined = code:get_chunk(Code, "XXXX"),
ok.
get_chunk_ok(Chunk, Code) ->
case code:get_chunk(Code, Chunk) of
Bin when is_binary(Bin) -> Bin
end.
module_md5(Config) when is_list(Config) ->
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "my_code_test"),
?line {ok,my_code_test,Code} = compile:file(File, [binary]),
%% Should work.
?line Chunk = module_md5_ok(Code),
?line Chunk = module_md5_ok(make_sub_binary(Code)),
?line Chunk = module_md5_ok(make_unaligned_sub_binary(Code)),
%% Should fail.
?line {'EXIT',{badarg,_}} = (catch code:module_md5(bit_sized_binary(Code))),
%% Invalid beam code should return 'undefined'.
?line undefined = code:module_md5(<<"not a beam module">>),
ok.
module_md5_ok(Code) ->
case code:module_md5(Code) of
Bin when is_binary(Bin), size(Bin) =:= 16 -> Bin
end.
make_stub(Config) when is_list(Config) ->
catch erlang:purge_module(my_code_test),
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "my_code_test"),
?line {ok,my_code_test,Code} = compile:file(File, [binary]),
?line my_code_test = code:make_stub_module(my_code_test, Code, {[],[]}),
?line true = erlang:delete_module(my_code_test),
?line true = erlang:purge_module(my_code_test),
?line my_code_test = code:make_stub_module(my_code_test,
make_unaligned_sub_binary(Code),
{[],[]}),
?line true = erlang:delete_module(my_code_test),
?line true = erlang:purge_module(my_code_test),
?line my_code_test = code:make_stub_module(my_code_test, zlib:gzip(Code),
{[],[]}),
?line true = erlang:delete_module(my_code_test),
?line true = erlang:purge_module(my_code_test),
%% Should fail.
?line {'EXIT',{badarg,_}} =
(catch code:make_stub_module(my_code_test, <<"bad">>, {[],[]})),
?line {'EXIT',{badarg,_}} =
(catch code:make_stub_module(my_code_test,
bit_sized_binary(Code),
{[],[]})),
?line {'EXIT',{badarg,_}} =
(catch code:make_stub_module(my_code_test_with_wrong_name,
Code, {[],[]})),
ok.
make_stub_many_funs(Config) when is_list(Config) ->
catch erlang:purge_module(many_funs),
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "many_funs"),
?line {ok,many_funs,Code} = compile:file(File, [binary]),
?line many_funs = code:make_stub_module(many_funs, Code, {[],[]}),
?line true = erlang:delete_module(many_funs),
?line true = erlang:purge_module(many_funs),
?line many_funs = code:make_stub_module(many_funs,
make_unaligned_sub_binary(Code),
{[],[]}),
?line true = erlang:delete_module(many_funs),
?line true = erlang:purge_module(many_funs),
%% Should fail.
?line {'EXIT',{badarg,_}} =
(catch code:make_stub_module(many_funs, <<"bad">>, {[],[]})),
?line {'EXIT',{badarg,_}} =
(catch code:make_stub_module(many_funs,
bit_sized_binary(Code),
{[],[]})),
ok.
constant_pools(Config) when is_list(Config) ->
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "literals"),
?line {ok,literals,Code} = compile:file(File, [report,binary]),
?line {module,literals} = erlang:load_module(literals,
make_sub_binary(Code)),
%% Initialize.
?line A = literals:a(),
?line B = literals:b(),
?line C = literals:huge_bignum(),
?line process_flag(trap_exit, true),
Self = self(),
%% Have a process WITHOUT old heap that references the literals
%% in the 'literals' module.
?line NoOldHeap = spawn_link(fun() -> no_old_heap(Self) end),
receive go -> ok end,
?line true = erlang:delete_module(literals),
?line false = erlang:check_process_code(NoOldHeap, literals),
?line erlang:check_process_code(self(), literals),
?line true = erlang:purge_module(literals),
?line NoOldHeap ! done,
?line receive
{'EXIT',NoOldHeap,{A,B,C}} ->
ok;
Other ->
?line ?t:fail({unexpected,Other})
end,
?line {module,literals} = erlang:load_module(literals, Code),
%% Have a process WITH an old heap that references the literals
%% in the 'literals' module.
?line OldHeap = spawn_link(fun() -> old_heap(Self) end),
receive go -> ok end,
?line true = erlang:delete_module(literals),
?line false = erlang:check_process_code(OldHeap, literals),
?line erlang:check_process_code(self(), literals),
?line erlang:purge_module(literals),
?line OldHeap ! done,
receive
{'EXIT',OldHeap,{A,B,C,[1,2,3|_]=Seq}} when length(Seq) =:= 16 ->
ok
end.
no_old_heap(Parent) ->
A = literals:a(),
B = literals:b(),
Res = {A,B,literals:huge_bignum()},
Parent ! go,
receive
done ->
exit(Res)
end.
old_heap(Parent) ->
A = literals:a(),
B = literals:b(),
Res = {A,B,literals:huge_bignum(),lists:seq(1, 16)},
create_old_heap(),
Parent ! go,
receive
done ->
exit(Res)
end.
create_old_heap() ->
case process_info(self(), [heap_size,total_heap_size]) of
[{heap_size,Sz},{total_heap_size,Total}] when Sz < Total ->
ok;
_ ->
create_old_heap()
end.
constant_refc_binaries(Config) when is_list(Config) ->
wait_for_memory_deallocations(),
Bef = memory_binary(),
io:format("Binary data (bytes) before test: ~p\n", [Bef]),
%% Compile the the literals module.
Data = ?config(data_dir, Config),
File = filename:join(Data, "literals"),
{ok,literals,Code} = compile:file(File, [report,binary]),
%% Load the code and make sure that the binary is a refc binary.
{module,literals} = erlang:load_module(literals, Code),
Bin = literals:binary(),
Sz = byte_size(Bin),
Check = erlang:md5(Bin),
io:format("Size of literal refc binary: ~p\n", [Sz]),
{refc_binary,Sz,_,_} = erts_debug:get_internal_state({binary_info,Bin}),
true = erlang:delete_module(literals),
false = erlang:check_process_code(self(), literals),
true = erlang:purge_module(literals),
%% Now try to provoke a memory leak.
provoke_mem_leak(10, Code, Check),
%% Calculate the change in allocated binary data.
erlang:garbage_collect(),
wait_for_memory_deallocations(),
Aft = memory_binary(),
io:format("Binary data (bytes) after test: ~p", [Aft]),
Diff = Aft - Bef,
if
Diff < 0 ->
io:format("~p less bytes", [abs(Diff)]);
Diff > 0 ->
io:format("~p more bytes", [Diff]);
true ->
ok
end,
%% Test for leaks. We must accept some natural variations in
%% the size of allocated binaries.
if
Diff > 64*1024 ->
?t:fail(binary_leak);
true ->
ok
end.
memory_binary() ->
try
erlang:memory(binary)
catch
error:notsup ->
0
end.
provoke_mem_leak(0, _, _) -> ok;
provoke_mem_leak(N, Code, Check) ->
{module,literals} = erlang:load_module(literals, Code),
%% Create several processes with references to the literal binary.
Self = self(),
Pids = [spawn_link(fun() ->
create_binaries(Self, NumRefs, Check)
end) || NumRefs <- lists:seq(1, 10)],
[receive {started,Pid} -> ok end || Pid <- Pids],
%% Make the code old and remove references to the constant pool
%% in all processes.
true = erlang:delete_module(literals),
Ms = [spawn_monitor(fun() ->
false = erlang:check_process_code(Pid, literals)
end) || Pid <- Pids],
[receive
{'DOWN',R,process,P,normal} ->
ok
end || {P,R} <- Ms],
%% Purge the code.
true = erlang:purge_module(literals),
%% Tell the processes that the code has been purged.
[begin
monitor(process, Pid),
Pid ! purged
end || Pid <- Pids],
%% Wait for all processes to terminate.
[receive
{'DOWN',_,process,Pid,normal} ->
ok
end || Pid <- Pids],
%% We now expect that the binary has been deallocated.
provoke_mem_leak(N-1, Code, Check).
create_binaries(Parent, NumRefs, Check) ->
Bin = literals:binary(),
Bins = lists:duplicate(NumRefs, Bin),
{bits,Bits} = literals:bits(),
Parent ! {started,self()},
receive
purged ->
%% The code has been purged. Now make sure that
%% the binaries haven't been corrupted.
Check = erlang:md5(Bin),
[Bin = B || B <- Bins],
<<42:13,Bin/binary>> = Bits,
%% Remove all references to the binaries
%% Doing it explicitly like this ensures that
%% the binaries are gone when the parent process
%% receives the 'DOWN' message.
erlang:garbage_collect()
end.
wait_for_memory_deallocations() ->
try
erts_debug:set_internal_state(wait, deallocations)
catch
error:undef ->
erts_debug:set_internal_state(available_internal_state, true),
wait_for_memory_deallocations()
end.
%% OTP-7559: c_p->cp could contain garbage and create a false dependency
%% to a module in a process. (Thanks to Richard Carlsson.)
false_dependency(Config) when is_list(Config) ->
?line Data = ?config(data_dir, Config),
?line File = filename:join(Data, "cpbugx"),
?line {ok,cpbugx,Code} = compile:file(File, [binary,report]),
do_false_dependency(fun cpbugx:before/0, Code),
do_false_dependency(fun cpbugx:before2/0, Code),
do_false_dependency(fun cpbugx:before3/0, Code),
%% %% Spawn process. Make sure it has called cpbugx:before/0 and returned.
%% Parent = self(),
%% ?line Pid = spawn_link(fun() -> false_dependency_loop(Parent) end),
%% ?line receive initialized -> ok end,
%% %% Reload the module. Make sure the process is still alive.
%% ?line {module,cpbugx} = erlang:load_module(cpbugx, Bin),
%% ?line io:put_chars(binary_to_list(element(2, process_info(Pid, backtrace)))),
%% ?line true = is_process_alive(Pid),
%% %% There should not be any dependency to cpbugx.
%% ?line false = erlang:check_process_code(Pid, cpbugx),
%% %% Kill the process.
%% ?line unlink(Pid), exit(Pid, kill),
ok.
do_false_dependency(Init, Code) ->
?line {module,cpbugx} = erlang:load_module(cpbugx, Code),
%% Spawn process. Make sure it has the appropriate init function
%% and returned. CP should not contain garbage after the return.
Parent = self(),
?line Pid = spawn_link(fun() -> false_dependency_loop(Parent, Init, true) end),
?line receive initialized -> ok end,
%% Reload the module. Make sure the process is still alive.
?line {module,cpbugx} = erlang:load_module(cpbugx, Code),
?line io:put_chars(binary_to_list(element(2, process_info(Pid, backtrace)))),
?line true = is_process_alive(Pid),
%% There should not be any dependency to cpbugx.
?line false = erlang:check_process_code(Pid, cpbugx),
%% Kill the process and completely unload the code.
?line unlink(Pid), exit(Pid, kill),
?line true = erlang:purge_module(cpbugx),
?line true = erlang:delete_module(cpbugx),
?line code:is_module_native(cpbugx), % test is_module_native on deleted code
?line true = erlang:purge_module(cpbugx),
?line code:is_module_native(cpbugx), % test is_module_native on purged code
ok.
false_dependency_loop(Parent, Init, SendInitAck) ->
Init(),
case SendInitAck of
true -> Parent ! initialized;
false -> void
%% Just send one init-ack. I guess the point of this test
%% wasn't to fill parents msg-queue (?). Seen to cause
%% out-of-mem (on halfword-vm for some reason) by
%% 91 million msg in queue. /sverker
end,
receive
_ -> false_dependency_loop(Parent, Init, false)
end.
coverage(Config) when is_list(Config) ->
?line code:is_module_native(?MODULE),
?line {'EXIT',{badarg,_}} = (catch erlang:purge_module({a,b,c})),
?line {'EXIT',{badarg,_}} = (catch code:is_module_native({a,b,c})),
?line {'EXIT',{badarg,_}} = (catch erlang:check_process_code(not_a_pid, ?MODULE)),
?line {'EXIT',{badarg,_}} = (catch erlang:check_process_code(self(), [not_a_module])),
?line {'EXIT',{badarg,_}} = (catch erlang:delete_module([a,b,c])),
?line {'EXIT',{badarg,_}} = (catch erlang:module_loaded(42)),
ok.
fun_confusion(Config) when is_list(Config) ->
Data = ?config(data_dir, Config),
Src = filename:join(Data, "fun_confusion"),
Mod = fun_confusion,
%% Load first version of module.
compile_load(Mod, Src, 1),
F1 = Mod:f(),
1 = F1(),
%% Load second version of module.
compile_load(Mod, Src, 2),
F2 = Mod:f(),
%% F1 should refer to the old code, not the newly loaded code.
1 = F1(),
2 = F2(),
ok.
compile_load(Mod, Src, Ver) ->
{ok,Mod,Code1} = compile:file(Src, [binary,{d,version,Ver}]),
{module,Mod} = code:load_binary(Mod, "fun_confusion.beam", Code1),
ok.
%% Utilities.
make_sub_binary(Bin) when is_binary(Bin) ->
{_,B1} = split_binary(list_to_binary([0,1,3,Bin,4,5,6,7]), 3),
{B,_} = split_binary(B1, size(Bin)),
B;
make_sub_binary(List) ->
make_sub_binary(list_to_binary(List)).
make_unaligned_sub_binary(Bin0) ->
Bin1 = <<0:3,Bin0/binary,31:5>>,
Sz = size(Bin0),
<<0:3,Bin:Sz/binary,31:5>> = id(Bin1),
Bin.
%% Add 1 bit to the size of the binary.
bit_sized_binary(Bin0) ->
Bin = <<Bin0/binary,1:1>>,
BitSize = bit_size(Bin),
BitSize = 8*size(Bin) + 1,
Bin.
id(I) -> I.
