Merge branch 'ta/werror' into dev

* ta/werror:
  snmp: extend warnings_as_errors test
  systools: add warnings_as_errors option
  asn1ct: add warnings_as_errors option
  leex: optimize werror/1
  yecc: optimize werror/1
  yecc: use more descriptive name: 'werror'
  leex: use more descriptive name: 'werror'
  compile: optimize werror/1
  compile: log warnings as errors if -Werror is enabled
  yecc: log warnings as errors if -Werror is enabled
  leex: log warnings as errors if -Werror is enabled
  yecc: honour -Werror passed from erlc
  leex: honour -Werror passed from erlc
  Do not write beam file if Werr and warnings /= []
  parsetools: test if warnings_as_errors writes file

OTP-9536

2 files changed, 83 insertions, 32 deletions

diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl
index ce8a5bf864..e46c667e47 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -113,7 +113,7 @@ noenv_forms(Forms, Opt) when is_atom(Opt) ->
 
 noenv_output_generated(Opts) ->
     {_,Passes} = passes(file, expand_opts(Opts)),
-    any(fun ({save_binary,_F}) -> true;
+    any(fun ({save_binary,_T,_F}) -> true;
 	    (_Other) -> false
 	end, Passes).
 
@@ -122,6 +122,7 @@ noenv_output_generated(Opts) ->
 %%
 
 -define(pass(P), {P,fun P/1}).
+-define(pass(P,T), {P,fun T/1,fun P/1}).
 
 env_default_opts() ->
     Key = "ERL_COMPILER_OPTIONS",
@@ -304,7 +305,7 @@ run_tc({Name,Fun}, St) ->
     Val.
 
 comp_ret_ok(#compile{code=Code,warnings=Warn0,module=Mod,options=Opts}=St) ->
-    case member(warnings_as_errors, Opts) andalso length(Warn0) > 0 of
+    case werror(St) of
         true ->
             case member(report_warnings, Opts) of
                 true ->
@@ -339,6 +340,11 @@ comp_ret_err(#compile{warnings=Warn0,errors=Err0,options=Opts}=St) ->
 	false -> error
     end.
 
+not_werror(St) -> not werror(St).
+
+werror(#compile{options=Opts,warnings=Ws}) ->
+    Ws =/= [] andalso member(warnings_as_errors, Opts).
+
 %% messages_per_file([{File,[Message]}]) -> [{File,[Message]}]
 messages_per_file(Ms) ->
     T = lists:sort([{File,M} || {File,Messages} <- Ms, M <- Messages]),
@@ -373,7 +379,7 @@ passes(Type, Opts) ->
     %% insert a first pass to remove the file (unless the
     %% source file is a BEAM file).
     {Ext,case last(Passes) of
-	     {save_binary,_Fun} ->
+	     {save_binary,_TestFun,_Fun} ->
 		 case Passes of
 		     [{read_beam_file,_}|_] ->
 			 %% The BEAM is both input and output.
@@ -655,7 +661,7 @@ asm_passes() ->
 
 binary_passes() ->
     [{native_compile,fun test_native/1,fun native_compile/1},
-     {unless,binary,?pass(save_binary)}].
+     {unless,binary,?pass(save_binary,not_werror)}].
 
 %%%
 %%% Compiler passes.
@@ -1379,28 +1385,34 @@ report_errors(#compile{options=Opts,errors=Errors}) ->
     end.
 
 report_warnings(#compile{options=Opts,warnings=Ws0}) ->
-    case member(report_warnings, Opts) of
+    Werror = member(warnings_as_errors, Opts),
+    P = case Werror of
+	    true -> "";
+	    false -> "Warning: "
+	end,
+    ReportWerror = Werror andalso member(report_errors, Opts),
+    case member(report_warnings, Opts) orelse ReportWerror of
 	true ->
-	    Ws1 = flatmap(fun({{F,_L},Eds}) -> format_message(F, Eds);
-			     ({F,Eds}) -> format_message(F, Eds) end,
+	    Ws1 = flatmap(fun({{F,_L},Eds}) -> format_message(F, P, Eds);
+			     ({F,Eds}) -> format_message(F, P, Eds) end,
 			  Ws0),
 	    Ws = lists:sort(Ws1),
 	    foreach(fun({_,Str}) -> io:put_chars(Str) end, Ws);
 	false -> ok
     end.
 
-format_message(F, [{{Line,Column}=Loc,Mod,E}|Es]) ->
-    M = {{F,Loc},io_lib:format("~s:~w:~w Warning: ~s\n",
-                                [F,Line,Column,Mod:format_error(E)])},
-    [M|format_message(F, Es)];
-format_message(F, [{Line,Mod,E}|Es]) ->
-    M = {{F,{Line,0}},io_lib:format("~s:~w: Warning: ~s\n",
-                                [F,Line,Mod:format_error(E)])},
-    [M|format_message(F, Es)];
-format_message(F, [{Mod,E}|Es]) ->
-    M = {none,io_lib:format("~s: Warning: ~s\n", [F,Mod:format_error(E)])},
-    [M|format_message(F, Es)];
-format_message(_, []) -> [].
+format_message(F, P, [{{Line,Column}=Loc,Mod,E}|Es]) ->
+    M = {{F,Loc},io_lib:format("~s:~w:~w ~s~s\n",
+                                [F,Line,Column,P,Mod:format_error(E)])},
+    [M|format_message(F, P, Es)];
+format_message(F, P, [{Line,Mod,E}|Es]) ->
+    M = {{F,{Line,0}},io_lib:format("~s:~w: ~s~s\n",
+                                [F,Line,P,Mod:format_error(E)])},
+    [M|format_message(F, P, Es)];
+format_message(F, P, [{Mod,E}|Es]) ->
+    M = {none,io_lib:format("~s: ~s~s\n", [F,P,Mod:format_error(E)])},
+    [M|format_message(F, P, Es)];
+format_message(_, _, []) -> [].
 
 %% list_errors(File, ErrorDescriptors) -> ok
 
diff --git a/lib/compiler/test/error_SUITE.erl b/lib/compiler/test/error_SUITE.erl
index 6e0aadf007..eb5e50818e 100644
--- a/lib/compiler/test/error_SUITE.erl
+++ b/lib/compiler/test/error_SUITE.erl
@@ -183,23 +183,47 @@ get_compilation_errors(Config, Filename) ->
     E.
 
 warnings_as_errors(Config) when is_list(Config) ->
-    Ts = [{warnings_as_errors,
+    ?line TestFile = test_filename(Config),
+    ?line BeamFile = filename:rootname(TestFile, ".erl") ++ ".beam",
+    ?line OutDir = ?config(priv_dir, Config),
+
+    Ts1 = [{warnings_as_errors,
            <<"
                t() ->
                  A = unused,
                  ok.
              ">>,
-           [export_all,warnings_as_errors],
-          {error,
-           [],
-           [{3,erl_lint,{unused_var,'A'}}]} }],
-    ?line [] = run(Config, Ts),
+	    [warnings_as_errors, export_all, {outdir, OutDir}],
+	    {error,
+	     [],
+	     [{3,erl_lint,{unused_var,'A'}}]} }],
+    ?line [] = run(Ts1, TestFile, write_beam),
+    ?line false = filelib:is_regular(BeamFile),
+
+    Ts2 = [{warning_unused_var,
+           <<"
+               t() ->
+                 A = unused,
+                 ok.
+             ">>,
+	    [return_warnings, export_all, {outdir, OutDir}],
+	    {warning,
+	       [{3,erl_lint,{unused_var,'A'}}]} }],
+
+    ?line [] = run(Ts2, TestFile, write_beam),
+    ?line true = filelib:is_regular(BeamFile),
+    ?line ok = file:delete(BeamFile),
+
     ok.
 
 
 run(Config, Tests) ->
+    ?line File = test_filename(Config),
+    run(Tests, File, dont_write_beam).
+
+run(Tests, File, WriteBeam) ->
     F = fun({N,P,Ws,E}, BadL) ->
-                case catch run_test(Config, P, Ws) of
+                case catch run_test(P, File, Ws, WriteBeam) of
                     E -> 
                         BadL;
                     Bad -> 
@@ -211,8 +235,12 @@ run(Config, Tests) ->
     lists:foldl(F, [], Tests).
 
 run2(Config, Tests) ->
+    ?line File = test_filename(Config),
+    run2(Tests, File, dont_write_beam).
+
+run2(Tests, File, WriteBeam) ->
     F = fun({N,P,Ws,E}, BadL) ->
-                case catch filter(run_test(Config, P, Ws)) of
+                case catch filter(run_test(P, File, Ws, WriteBeam)) of
                     E ->
                         BadL;
                     Bad ->
@@ -231,12 +259,19 @@ filter(X) ->
 
 %% Compiles a test module and returns the list of errors and warnings.
 
-run_test(Conf, Test0, Warnings) ->
-    Filename = 'errors_test.erl',
-    ?line DataDir = ?config(priv_dir, Conf),
+test_filename(Conf) ->
+    Filename = "errors_test.erl",
+    DataDir = ?config(priv_dir, Conf),
+    filename:join(DataDir, Filename).
+
+run_test(Test0, File, Warnings, WriteBeam) ->
     ?line Test = ["-module(errors_test). ", Test0],
-    ?line File = filename:join(DataDir, Filename),
-    ?line Opts = [binary,return_errors|Warnings],
+    ?line Opts = case WriteBeam of
+		     dont_write_beam ->
+			 [binary,return_errors|Warnings];
+		     write_beam ->
+			 [return_errors|Warnings]
+		 end,
     ?line ok = file:write_file(File, Test),
 
     %% Compile once just to print all errors and warnings.
@@ -252,6 +287,10 @@ run_test(Conf, Test0, Warnings) ->
 			%io:format("compile:file(~s,~p) ->~n~p~n",
 			%	  [File,Opts,Ws]),
 			[];
+		    {ok,errors_test,[{_File,Ws}]} ->
+			{warning,Ws};
+		    {ok,errors_test,[]} ->
+			[];
 		    {error,[{XFile,Es}],Ws} = _ZZ when is_list(XFile) ->
 			%io:format("compile:file(~s,~p) ->~n~p~n",
 			%	  [File,Opts,_ZZ]),