Merge tag 'OTP-19.0' into sverker/19/binary_to_atom-utf8-crash/ERL-474/OTP-14590

1 files changed, 86 insertions, 172 deletions

diff --git a/lib/kernel/src/os.erl b/lib/kernel/src/os.erl
index ded03361ee..f0ad26b1f2 100644
--- a/lib/kernel/src/os.erl
+++ b/lib/kernel/src/os.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. 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/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% 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.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -26,7 +27,10 @@
 
 %%% BIFs
 
--export([getenv/0, getenv/1, getpid/0, putenv/2, timestamp/0]).
+-export([getenv/0, getenv/1, getenv/2, getpid/0,
+         perf_counter/0, perf_counter/1,
+         putenv/2, system_time/0, system_time/1,
+	 timestamp/0, unsetenv/1]).
 
 -spec getenv() -> [string()].
 
@@ -39,12 +43,37 @@ getenv() -> erlang:nif_error(undef).
 getenv(_) ->
     erlang:nif_error(undef).
 
+-spec getenv(VarName, DefaultValue) -> Value when
+      VarName :: string(),
+      DefaultValue :: string(),
+      Value :: string().
+
+getenv(VarName, DefaultValue) ->
+    case os:getenv(VarName) of
+        false ->
+           DefaultValue;
+        Value ->
+            Value
+    end.
+
 -spec getpid() -> Value when
       Value :: string().
 
 getpid() ->
     erlang:nif_error(undef).
 
+-spec perf_counter() -> Counter when
+      Counter :: integer().
+
+perf_counter() ->
+    erlang:nif_error(undef).
+
+-spec perf_counter(Unit) -> integer() when
+      Unit :: erlang:time_unit().
+
+perf_counter(Unit) ->
+      erlang:convert_time_unit(os:perf_counter(), perf_counter, Unit).
+
 -spec putenv(VarName, Value) -> true when
       VarName :: string(),
       Value :: string().
@@ -52,12 +81,29 @@ getpid() ->
 putenv(_, _) ->
     erlang:nif_error(undef).
 
+-spec system_time() -> integer().
+
+system_time() ->
+    erlang:nif_error(undef).
+
+-spec system_time(Unit) -> integer() when
+      Unit :: erlang:time_unit().
+
+system_time(_Unit) ->
+    erlang:nif_error(undef).
+
 -spec timestamp() -> Timestamp when
       Timestamp :: erlang:timestamp().
 
 timestamp() ->
     erlang:nif_error(undef).
 
+-spec unsetenv(VarName) -> true when
+      VarName :: string().
+
+unsetenv(_) ->
+    erlang:nif_error(undef).
+
 %%% End of BIFs
 
 -spec type() -> {Osfamily, Osname} when
@@ -79,10 +125,7 @@ version() ->
       Name :: string(),
       Filename :: string().
 find_executable(Name) ->
-    case os:getenv("PATH") of
-	false -> find_executable(Name, []);
-	Path  -> find_executable(Name, Path)
-    end.
+    find_executable(Name, os:getenv("PATH", "")).
 
 -spec find_executable(Name, Path) -> Filename | 'false' when
       Name :: string(),
@@ -183,169 +226,40 @@ extensions() ->
       Command :: atom() | io_lib:chars().
 cmd(Cmd) ->
     validate(Cmd),
-    case type() of
-	{unix, _} ->
-	    unix_cmd(Cmd);
-	{win32, Wtype} ->
-	    Command0 = case {os:getenv("COMSPEC"),Wtype} of
-			  {false,windows} -> lists:concat(["command.com /c", Cmd]);
-			  {false,_} -> lists:concat(["cmd /c", Cmd]);
-			  {Cspec,_} -> lists:concat([Cspec," /c",Cmd])
-		      end,
-            %% open_port/2 awaits string() in Command, but io_lib:chars() can be
-            %% deep lists according to io_lib module description.
-            Command = lists:flatten(Command0),
-	    Port = open_port({spawn, Command}, [stream, in, eof, hide]),
-	    get_data(Port, [])
-    end.
-
-unix_cmd(Cmd) ->
-    Tag = make_ref(),
-    {Pid,Mref} = erlang:spawn_monitor(
-		   fun() ->
-			   process_flag(trap_exit, true),
-			   Port = start_port(),
-			   erlang:port_command(Port, mk_cmd(Cmd)),
-			   exit({Tag,unix_get_data(Port)})
-		   end),
-    receive
-	{'DOWN',Mref,_,Pid,{Tag,Result}} ->
-	    Result;
-	{'DOWN',Mref,_,Pid,Reason} ->
-	    exit(Reason)
-    end.
-
-%% The -s flag implies that only the positional parameters are set,
-%% and the commands are read from standard input. We set the
-%% $1 parameter for easy identification of the resident shell.
-%%
--define(SHELL, "/bin/sh -s unix:cmd 2>&1").
--define(PORT_CREATOR_NAME, os_cmd_port_creator).
-
-%%
-%% Serializing open_port through a process to avoid smp lock contention
-%% when many concurrent os:cmd() want to do vfork (OTP-7890).
-%%
--spec start_port() -> port().
-start_port() ->
-    Ref = make_ref(),
-    Request = {Ref,self()},
-    {Pid, Mon} = case whereis(?PORT_CREATOR_NAME) of
-		     undefined ->
-			 spawn_monitor(fun() ->
-					       start_port_srv(Request)
-				       end);
-		     P ->
-			 P ! Request,
-			 M = erlang:monitor(process, P),
-			 {P, M}
-		 end,
-    receive
-	{Ref, Port} when is_port(Port) ->
-	    erlang:demonitor(Mon, [flush]),
-	    Port;
-	{Ref, Error} ->
-	    erlang:demonitor(Mon, [flush]),
-	    exit(Error);
-	{'DOWN', Mon, process, Pid, _Reason} ->
-	    start_port()
-    end.
-
-start_port_srv(Request) ->
-    %% We don't want a group leader of some random application. Use
-    %% kernel_sup's group leader.
-    {group_leader, GL} = process_info(whereis(kernel_sup),
-				      group_leader),
-    true = group_leader(GL, self()),
-    process_flag(trap_exit, true),
-    StayAlive = try register(?PORT_CREATOR_NAME, self())
-		catch
-		    error:_ -> false
-		end,
-    start_port_srv_handle(Request),
-    case StayAlive of
-	true -> start_port_srv_loop();
-	false -> exiting
+    {SpawnCmd, SpawnOpts, SpawnInput} = mk_cmd(os:type(), Cmd),
+    Port = open_port({spawn, SpawnCmd}, [binary, stderr_to_stdout,
+                                         stream, in, eof, hide | SpawnOpts]),
+    true = port_command(Port, SpawnInput),
+    Bytes = get_data(Port, []),
+    String = unicode:characters_to_list(Bytes),
+    if  %% Convert to unicode list if possible otherwise return bytes
+	is_list(String) -> String;
+	true -> binary_to_list(Bytes)
     end.
 
-start_port_srv_handle({Ref,Client}) ->
-    Reply = try open_port({spawn, ?SHELL},[stream]) of
-		Port when is_port(Port) ->
-		    (catch port_connect(Port, Client)),
-		    unlink(Port),
-		    Port
-	    catch
-		error:Reason ->
-		    {Reason,erlang:get_stacktrace()}
-	    end,
-    Client ! {Ref,Reply}.
-
-
-start_port_srv_loop() ->
-    receive
-	{Ref, Client} = Request when is_reference(Ref),
-				     is_pid(Client) ->
-	    start_port_srv_handle(Request);
-	_Junk ->
-	    ignore
-    end,
-    start_port_srv_loop().
-
-%%
-%%  unix_get_data(Port) -> Result
-%%
-unix_get_data(Port) ->
-    unix_get_data(Port, []).
-
-unix_get_data(Port, Sofar) ->
-    receive
-	{Port,{data, Bytes}} ->
-	    case eot(Bytes) of
-		{done, Last} ->
-		    lists:flatten([Sofar|Last]);
-		more  ->
-		    unix_get_data(Port, [Sofar|Bytes])
-	    end;
-	{'EXIT', Port, _} ->
-	    lists:flatten(Sofar)
-    end.
-
-%%
-%% eot(String) -> more | {done, Result}
-%%
-eot(Bs) ->
-    eot(Bs, []).
-
-eot([4| _Bs], As) ->
-    {done, lists:reverse(As)};
-eot([B| Bs], As) ->
-    eot(Bs, [B| As]);
-eot([], _As) ->
-    more.
-
-%%
-%% mk_cmd(Cmd) -> {ok, ShellCommandString} | {error, ErrorString}
-%%
-%% We do not allow any input to Cmd (hence commands that want
-%% to read from standard input will return immediately).
-%% Standard error is redirected to standard output.
-%%
-%% We use ^D (= EOT = 4) to mark the end of the stream.
-%%
-mk_cmd(Cmd) when is_atom(Cmd) ->		% backward comp.
-    mk_cmd(atom_to_list(Cmd));
-mk_cmd(Cmd) ->
-    %% We insert a new line after the command, in case the command
-    %% contains a comment character.
-    io_lib:format("(~ts\n) </dev/null; echo  \"\^D\"\n", [Cmd]).
-
+mk_cmd({win32,Wtype}, Cmd) ->
+    Command = case {os:getenv("COMSPEC"),Wtype} of
+                  {false,windows} -> lists:concat(["command.com /c", Cmd]);
+                  {false,_} -> lists:concat(["cmd /c", Cmd]);
+                  {Cspec,_} -> lists:concat([Cspec," /c",Cmd])
+              end,
+    {Command, [], []};
+mk_cmd(OsType,Cmd) when is_atom(Cmd) ->
+    mk_cmd(OsType, atom_to_list(Cmd));
+mk_cmd(_,Cmd) ->
+    %% Have to send command in like this in order to make sh commands like
+    %% cd and ulimit available
+    {"/bin/sh -s unix:cmd", [out],
+     %% We insert a new line after the command, in case the command
+     %% contains a comment character.
+     ["(", unicode:characters_to_binary(Cmd), "\n); exit\n"]}.
 
 validate(Atom) when is_atom(Atom) ->
     ok;
 validate(List) when is_list(List) ->
     validate1(List).
 
-validate1([C|Rest]) when is_integer(C), 0 =< C, C < 256 ->
+validate1([C|Rest]) when is_integer(C) ->
     validate1(Rest);
 validate1([List|Rest]) when is_list(List) ->
     validate1(List),
@@ -356,7 +270,7 @@ validate1([]) ->
 get_data(Port, Sofar) ->
     receive
 	{Port, {data, Bytes}} ->
-	    get_data(Port, [Sofar|Bytes]);
+	    get_data(Port, [Sofar,Bytes]);
 	{Port, eof} ->
 	    Port ! {self(), close},
 	    receive
@@ -369,5 +283,5 @@ get_data(Port, Sofar) ->
 	    after 1 ->				% force context switch
 		    ok
 	    end,
-	    lists:flatten(Sofar)
+	    iolist_to_binary(Sofar)
     end.