Make options in the -compile attribute take precedence

Change the compiler option processing order so that options given
in the `compile()` attribute takes precedence over options given
to the compiler, which in turn takes precedence over options given
in the environment.

This order makes most sense, as each module might need customized
options.

While at it, remove the undocumented `strict_record_updates` /
`no_strict_record_updates` options. Their naming no longer make any
sense, because record updates are always strict (that is, the source
record must have the correct tag and size). Incorporate the
behavior of `strict_record_updates` to update the record by matching
and building a new tuple into the `dialyzer` option. When dialyzer
is not used, records are updated using `setelement/3`, which is more
efficient in the JIT.

(This is the second attempt to fix erlang#6979, as erlang#8093 did not really
work.)

Author: bjorng

lib/compiler/src/compile.erl

@@ -43,6 +43,23 @@ compiler recursively from inside a parse transform.
 
 The list can be retrieved with `env_compiler_options/0`.
 
+## Order of Compiler Options
+
+Options given in the `compile()` attribute in the source code takes
+precedence over options given to the compiler, which in turn takes
+precedence over options given in the environment.
+
+A later compiler option takes precedence over an earlier one in the
+option list. Example:
+
+```
+compile:file(something, [nowarn_missing_spec,warn_missing_spec]).
+```
+
+Warnings will be emitted for functions without specifications, unless
+the source code for module `something` contains a `compile(nowarn_missing_spec)`
+attribute.
+
 ## Inlining
 
 The compiler can do function inlining within an Erlang
@@ -792,7 +809,7 @@ Module:format_error(ErrorDescriptor)
           CompRet :: comp_ret().
 
 file(File, Opts) when is_list(Opts) ->
-    do_compile({file,File}, Opts++env_default_opts());
+    do_compile({file,File}, env_default_opts() ++ Opts);
 file(File, Opt) ->
     file(File, [Opt|?DEFAULT_OPTIONS]).
 

lib/compiler/test/compile_SUITE.erl

@@ -39,7 +39,7 @@
          bc_options/1, deterministic_include/1, deterministic_paths/1,
          compile_attribute/1, message_printing/1, other_options/1,
          transforms/1, erl_compile_api/1, types_pp/1, bs_init_writable/1,
-         annotations_pp/1
+         annotations_pp/1, option_order/1
 	]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
@@ -59,7 +59,8 @@ all() ->
      env_compiler_options, custom_debug_info, bc_options,
      custom_compile_info, deterministic_include, deterministic_paths,
      compile_attribute, message_printing, other_options, transforms,
-     erl_compile_api, types_pp, bs_init_writable, annotations_pp].
+     erl_compile_api, types_pp, bs_init_writable, annotations_pp,
+     option_order].
 
 groups() -> 
     [].
@@ -906,10 +907,10 @@ strict_record(Config) when is_list(Config) ->
     {ok,M} = c:c(M, [no_strict_record_tests|Opts]),
     Turtle = test_sloppy(),
 
-    %% The option first given wins.
-    {ok,M} = c:c(M, [no_strict_record_tests,strict_record_tests|Opts]),
-    Turtle = test_sloppy(),
+    %% The option last given wins.
     {ok,M} = c:c(M, [strict_record_tests,no_strict_record_tests|Opts]),
+    Turtle = test_sloppy(),
+    {ok,M} = c:c(M, [no_strict_record_tests,strict_record_tests|Opts]),
     Turtle = test_strict(),
 
     %% Default (possibly influenced by ERL_COMPILER_OPTIONS).
@@ -2120,6 +2121,146 @@ get_annotations(Key, [_|Lines]) ->
 get_annotations(_, []) ->
     [].
 
+option_order(Config) ->
+    Ts = [{spec1,
+           ~"""
+            -compile(nowarn_missing_spec).
+            foo() -> ok.
+            """,
+           [],                                  %Environment
+           [warn_missing_spec],
+           []},
+          {spec2,
+           ~"""
+            foo() -> ok.
+            """,
+           [{"ERL_COMPILER_OPTIONS", "warn_missing_spec"}],
+           [nowarn_missing_spec],
+           []},
+          {spec3,
+           ~"""
+            -compile(nowarn_missing_spec).
+            foo() -> ok.
+            """,
+           [{"ERL_COMPILER_OPTIONS", "nowarn_missing_spec"}],
+           [warn_missing_spec],
+           []},
+          {spec4,
+           ~"""
+            -compile(warn_missing_spec).
+            foo() -> ok.
+            """,
+           [{"ERL_COMPILER_OPTIONS", "nowarn_missing_spec"}],
+           [],
+           {warnings,[{{2,1},erl_lint,{missing_spec,{foo,0}}}]}
+          },
+          {spec5,
+           ~"""
+            -compile([warn_missing_spec,nowarn_missing_spec]).
+            foo() -> ok.
+            """,
+           [{"ERL_COMPILER_OPTIONS", "nowarn_missing_spec"}],
+           [warn_missing_spec],
+           []},
+          {records1,
+           ~"""
+            -record(r, {x,y}).
+            rec_test(#r{x=X,y=Y}) -> X + Y.
+            """,
+           [],
+           [strict_record_tests],
+           fun(M) ->
+                   try M:rec_test({r,1,2,3}) of
+                       3 ->
+                           fail()
+                   catch
+                       error:function_clause ->
+                           ok
+                   end
+           end},
+          {records2,
+           ~"""
+            -record(r, {x,y}).
+            rec_test(R) -> R#r.x + R#r.y.
+            """,
+           [],
+           [no_strict_record_tests],
+           fun(M) ->
+                   3 = M:rec_test({r,1,2,3}),
+                   ok
+           end},
+          {records3,
+           ~"""
+            -compile(no_strict_record_tests).
+            -record(r, {x,y}).
+            rec_test(R) -> R#r.x + R#r.y.
+            """,
+           [],
+           [strict_record_tests],
+           fun(M) ->
+                   3 = M:rec_test({r,1,2,3}),
+                   ok
+           end},
+          {records4,
+           ~"""
+            -record(r, {x,y}).
+            rec_test(#r{x=X,y=Y}) -> X + Y.
+            """,
+           [{"ERL_COMPILER_OPTIONS", "strict_record_tests"}],
+           [],
+           fun(M) ->
+                   try M:rec_test({r,1,2,3}) of
+                       3 ->
+                           fail()
+                   catch
+                       error:function_clause ->
+                           ok
+                   end
+           end},
+          {records5,
+           ~"""
+            -record(r, {x,y}).
+            rec_test(R) -> R#r.x + R#r.y.
+            """,
+           [{"ERL_COMPILER_OPTIONS", "strict_record_tests"}],
+           [no_strict_record_tests],
+           fun(M) ->
+                   3 = M:rec_test({r,1,2,3}),
+                   ok
+           end},
+          {records6,
+           ~"""
+            -compile(no_strict_record_tests).
+            -record(r, {x,y}).
+            rec_test(R) -> R#r.x + R#r.y.
+            """,
+           [{"ERL_COMPILER_OPTIONS", "strict_record_tests"}],
+           [],
+           fun(M) ->
+                   3 = M:rec_test({r,1,2,3}),
+                   ok
+           end},
+          {records7,
+           ~"""
+            -record(r, {x,y}).
+            rec_test(R) -> R#r.x + R#r.y.
+            """,
+           [{"ERL_COMPILER_OPTIONS", "no_strict_record_tests"}],
+           [no_strict_record_tests, strict_record_tests],
+           fun(M) ->
+                   try M:rec_test({r,1,2,3}) of
+                       3 ->
+                           fail()
+                   catch
+                       error:{badrecord,{r,1,2,3}} ->
+                           ok
+                   end
+           end}
+
+         ],
+    run(Config, Ts),
+    ok.
+
 %%%
 %%% Utilities.
 %%%
@@ -2149,3 +2290,104 @@ is_lfe_module(File, Ext) ->
 	"lfe_" ++ _ -> true;
 	_ -> false
     end.
+
+%% Compiles a test module and returns the list of errors and warnings.
+
+run(Config, Tests) ->
+    F = fun({N,P,Env,Ws,Run}, _BadL) when is_function(Run, 1) ->
+                case catch run_test(Config, P, Env, Ws, Run) of
+                    ok ->
+                        ok;
+                    Bad ->
+                        io:format("~nTest ~p failed. Expected~n  ~p~n"
+                                  "but got~n  ~p~n", [N, ok, Bad]),
+                        fail()
+                end;
+           ({N,P,Env,Ws,Expected}, BadL)
+              when is_list(Expected); is_tuple(Expected) ->
+                io:format("### ~s\n", [N]),
+                case catch run_test(Config, P, Env, Ws, none) of
+                    Expected ->
+                        BadL;
+                    Bad ->
+                        io:format("~nTest ~p failed. Expected~n  ~p~n"
+                                  "but got~n  ~p~n", [N, Expected, Bad]),
+			fail()
+                end
+        end,
+    lists:foldl(F, [], Tests).
+
+run_test(Conf, Test0, Env, Options, Run) ->
+    run_test_putenv(Env),
+    Module = "warnings" ++ test_lib:uniq(),
+    Filename = Module ++ ".erl",
+    DataDir = proplists:get_value(priv_dir, Conf),
+    Test1 = ["-module(", Module, "). -file( \"", Filename, "\", 1). ", Test0],
+    Test = iolist_to_binary(Test1),
+    File = filename:join(DataDir, Filename),
+    Opts = [binary,export_all,return|Options],
+    ok = file:write_file(File, Test),
+
+    %% Compile once just to print all warnings (and cover more code).
+    _ = compile:file(File, [binary,export_all,report|Options]),
+
+    %% Test result of compilation.
+    {ok, Mod, Beam, Warnings} = compile:file(File, Opts),
+    _ = file:delete(File),
+
+    if
+        is_function(Run, 1) ->
+            {module,Mod} = code:load_binary(Mod, "", Beam),
+            ok = Run(Mod),
+            run_test_unsetenv(Env),
+            true = code:delete(Mod),
+            _ = code:purge(Mod),
+            ok;
+        Run =:= none ->
+            run_test_unsetenv(Env),
+            Res = get_warnings(Warnings),
+            case Res of
+                [] ->
+                    [];
+                {warnings, Ws} ->
+                    print_warnings(Ws, Test),
+                    Res
+            end
+    end.
+
+run_test_putenv(Env) ->
+    _ = [_ = os:putenv(Name, Value) || {Name,Value} <- Env],
+    ok.
+
+run_test_unsetenv(Env) ->
+    _ = [_ = os:unsetenv(Name) || {Name,_Value} <- Env],
+    ok.
+
+get_warnings([]) ->
+    [];
+get_warnings(WsL) ->
+    case WsL of
+        [{_File,Ws}] -> {warnings, Ws};
+        _ -> {warnings, WsL}
+    end.
+
+print_warnings(Warnings, Source) ->
+    Lines = binary:split(Source, <<"\n">>, [global]),
+    Cs = [print_warning(W, Lines) || W <- Warnings],
+    io:put_chars(Cs),
+    ok.
+
+print_warning({{LineNum,Column},Mod,Data}, Lines) ->
+    Line0 = lists:nth(LineNum, Lines),
+    <<Line1:(Column-1)/binary,_/binary>> = Line0,
+    Spaces = re:replace(Line1, <<"[^\t]">>, <<" ">>, [global]),
+    CaretLine = [Spaces,"^"],
+    [io_lib:format("~p:~p: ~ts\n",
+                   [LineNum,Column,Mod:format_error(Data)]),
+     Line0, "\n",
+     CaretLine, "\n\n"];
+print_warning(_, _) ->
+    [].
+
+fail() ->
+    ct:fail(failed).

lib/dialyzer/src/dialyzer_utils.erl

@@ -767,7 +767,7 @@ sets_filter([Mod|Mods], ExpTypes) ->
 
 src_compiler_opts() ->
   [no_copt, to_core, binary, return_errors,
-   no_inline, strict_record_tests, strict_record_updates,
+   no_inline, strict_record_tests,
    dialyzer, no_spawn_compiler_process].
 
 -spec format_errors([{module(), string()}]) -> [string()].