Merge branch 'pan/otp_8579_autoimport_override' into dev

* origin/pan/otp_8579_autoimport_override:
  Update preloaded modules
  Update primary bootstrap
  Remove outcommented code from erl_lint
  Make port_command/3 auto-imported
  Remove (harmless) warnings about min/max in core applications
  Autoimport min/2 and max/2
  Improve coverage of erl_int in testcases
  Change warning to error for nowarn_bif_clash compiler directive
  Add -compile({no_auto_import,[F/A]}) doc to compiler.xml
  Add some testcases to compiler to verify that overriding really happens
  Return nowarn_bif_clash functionality but with warning
  Teach erl_lint to better override BIFs with local functions and imports
  Teach compiler to override autoimport with import
  First prototype for local functions overriding autoimported

OTP-8579  Local functions should override auto-imported

Local and imported functions now override the autoimported
BIFs when the names clash. The pre R14 behaviour was that
autoimported BIFs would override local functions. To avoid
that old programs change behaviour, the following will
generate an error:

Doing a call without explicit module name to a local function
having a name clashing with the name of an autoimported BIF
that was present (and autoimported) before OTP R14A
Explicitly importing a function having a name clashing with
the name of an autoimported BIF that was present (and
autoimported) before OTP R14A Using any form of the old
compiler directive nowarn_bif_clash

If the BIF was added or autoimported in OTP R14A or later,
overriding it with an import or a local function will only
result in a warning,

To resolve clashes, you can either use the explicit module
name erlang to call the BIF, or you can remove the autoimport
of that specific BIF by using the new compiler directive
-compile({no_auto_import,[F/A]})., which makes all calls to
the local or imported function without explicit module name
pass without warnings or errors.

The change makes it possible to add autoimported BIFs without
breaking or silently changing old code in the future. However
some current code ingeniously utilizing the old behaviour or
the nowarn_bif_clash compiler directive, might need changing
to be accepted by the compiler.

1 files changed, 207 insertions, 17 deletions

diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl
index 8581b496aa..01f494ee38 100644
--- a/lib/stdlib/test/erl_lint_SUITE.erl
+++ b/lib/stdlib/test/erl_lint_SUITE.erl
@@ -1784,6 +1784,9 @@ otp_5362(Config) when is_list(Config) ->
                       {15,erl_lint,{undefined_field,ok,nix}},
                       {16,erl_lint,{field_name_is_variable,ok,'Var'}}]}},
 
+	  %% Nowarn_bif_clash has changed behaviour as local functions
+	  %% nowdays supersede auto-imported BIFs, why nowarn_bif_clash in itself generates an error
+	  %% (OTP-8579) /PaN
           {otp_5362_4,
            <<"-compile(nowarn_deprecated_function).
               -compile(nowarn_bif_clash).
@@ -1795,9 +1798,8 @@ otp_5362(Config) when is_list(Config) ->
              warn_deprecated_function,
              warn_bif_clash]},
            {error,
-            [{5,erl_lint,{call_to_redefined_bif,{spawn,1}}}],
-	    [{3,erl_lint,{redefine_bif,{spawn,1}}},
-             {4,erl_lint,{deprecated,{erlang,hash,2},{erlang,phash2,2},
+            [{5,erl_lint,{call_to_redefined_old_bif,{spawn,1}}}],
+	    [{4,erl_lint,{deprecated,{erlang,hash,2},{erlang,phash2,2},
 			  "in a future release"}}]}},
 
           {otp_5362_5,
@@ -1808,8 +1810,8 @@ otp_5362(Config) when is_list(Config) ->
                   spawn(A).
            ">>,
            {[nowarn_unused_function]},
-           {warnings,
-            [{3,erl_lint,{redefine_bif,{spawn,1}}}]}},
+	   {errors,
+            [{2,erl_lint,disallowed_nowarn_bif_clash}],[]}},
 
           %% The special nowarn_X are not affected by general warn_X.
           {otp_5362_6,
@@ -1822,8 +1824,8 @@ otp_5362(Config) when is_list(Config) ->
            {[nowarn_unused_function, 
              warn_deprecated_function, 
              warn_bif_clash]},
-           {warnings,
-            [{3,erl_lint,{redefine_bif,{spawn,1}}}]}},
+           {errors,
+            [{2,erl_lint,disallowed_nowarn_bif_clash}],[]}},
 
           {otp_5362_7,
            <<"-export([spawn/1]).
@@ -1838,7 +1840,9 @@ otp_5362(Config) when is_list(Config) ->
                   spawn(A).
            ">>,
            {[nowarn_unused_function]},
-           {error,[{4,erl_lint,{bad_nowarn_bif_clash,{spawn,2}}}],
+           {error,[{3,erl_lint,disallowed_nowarn_bif_clash},
+		   {4,erl_lint,disallowed_nowarn_bif_clash},
+		   {4,erl_lint,{bad_nowarn_bif_clash,{spawn,2}}}],
             [{5,erl_lint,{bad_nowarn_deprecated_function,{3,hash,-1}}},
              {5,erl_lint,{bad_nowarn_deprecated_function,{erlang,hash,-1}}},
              {5,erl_lint,{bad_nowarn_deprecated_function,{{a,b,c},hash,-1}}}]}
@@ -1865,7 +1869,21 @@ otp_5362(Config) when is_list(Config) ->
               t() -> #a{}.
           ">>,
            {[]},
-           []}
+           []},
+
+          {otp_5362_10,
+           <<"-compile({nowarn_deprecated_function,{erlang,hash,2}}).
+              -compile({nowarn_bif_clash,{spawn,1}}).
+              -import(x,[spawn/1]).
+              spin(A) ->
+                  erlang:hash(A, 3000),
+                  spawn(A).
+           ">>,
+           {[nowarn_unused_function,
+             warn_deprecated_function,
+             warn_bif_clash]},
+           {errors,
+            [{2,erl_lint,disallowed_nowarn_bif_clash}],[]}}
 
           ],
 
@@ -2389,9 +2407,9 @@ bif_clash(Config) when is_list(Config) ->
                 N.
              ">>,
            [],
-	   {errors,[{2,erl_lint,{call_to_redefined_bif,{size,1}}}],[]}},
+	   {errors,[{2,erl_lint,{call_to_redefined_old_bif,{size,1}}}],[]}},
 
-	  %% Verify that (some) warnings can be turned off.
+	  %% Verify that warnings can not be turned off in the old way.
 	  {clash2,
            <<"-export([t/1,size/1]).
               t(X) ->
@@ -2400,17 +2418,189 @@ bif_clash(Config) when is_list(Config) ->
               size({N,_}) ->
                 N.
 
-              %% My own abs/1 function works on lists too.
-              %% Unfortunately, it is not exported, so there will
-              %% be a warning that can't be turned off.
+              %% My own abs/1 function works on lists too. From R14 this really works.
               abs([H|T]) when $a =< H, H =< $z -> [H-($a-$A)|abs(T)];
               abs([H|T]) -> [H|abs(T)];
               abs([]) -> [];
               abs(X) -> erlang:abs(X).
              ">>,
-	   {[nowarn_bif_clash]},
-	   {warnings,[{11,erl_lint,{redefine_bif,{abs,1}}},
-		      {11,erl_lint,{unused_function,{abs,1}}}]}}],
+	   {[nowarn_unused_function,nowarn_bif_clash]},
+	   {errors,[{erl_lint,disallowed_nowarn_bif_clash}],[]}},
+	  %% As long as noone calls an overridden BIF, it's totally OK
+	  {clash3,
+           <<"-export([size/1]).
+              size({N,_}) ->
+                N;
+              size(X) ->
+                erlang:size(X).
+             ">>,
+	   [],
+	   []},
+	  %% But this is totally wrong - meaning of the program changed in R14, so this is an error
+	  {clash4,
+           <<"-export([size/1]).
+              size({N,_}) ->
+                N;
+              size(X) ->
+                size(X).
+             ">>,
+	   [],
+	   {errors,[{5,erl_lint,{call_to_redefined_old_bif,{size,1}}}],[]}},
+	  %% For a post R14 bif, its only a warning
+	  {clash5,
+           <<"-export([binary_part/2]).
+              binary_part({B,_},{X,Y}) ->
+                binary_part(B,{X,Y});
+              binary_part(B,{X,Y}) ->
+                binary:part(B,X,Y).
+             ">>,
+	   [],
+	   {warnings,[{3,erl_lint,{call_to_redefined_bif,{binary_part,2}}}]}},
+	  %% If you really mean to call yourself here, you can "unimport" size/1
+	  {clash6,
+           <<"-export([size/1]).
+              -compile({no_auto_import,[size/1]}).
+              size([]) ->
+                0;
+              size({N,_}) ->
+                N;
+              size([_|T]) ->
+                1+size(T).
+             ">>,
+	   [],
+	   []},
+	  %% Same for the post R14 autoimport warning
+	  {clash7,
+           <<"-export([binary_part/2]).
+              -compile({no_auto_import,[binary_part/2]}).
+              binary_part({B,_},{X,Y}) ->
+                binary_part(B,{X,Y});
+              binary_part(B,{X,Y}) ->
+                binary:part(B,X,Y).
+             ">>,
+	   [],
+	   []},
+          %% but this doesn't mean the local function is allowed in a guard...
+	  {clash8,
+           <<"-export([x/1]).
+              -compile({no_auto_import,[binary_part/2]}).
+              x(X) when binary_part(X,{1,2}) =:= <<1,2>> ->
+                 hej.
+              binary_part({B,_},{X,Y}) ->
+                binary_part(B,{X,Y});
+              binary_part(B,{X,Y}) ->
+                binary:part(B,X,Y).
+             ">>,
+	   [],
+	   {errors,[{3,erl_lint,illegal_guard_expr}],[]}},
+          %% no_auto_import is not like nowarn_bif_clash, it actually removes the autoimport
+	  {clash9,
+           <<"-export([x/1]).
+              -compile({no_auto_import,[binary_part/2]}).
+              x(X) ->
+                 binary_part(X,{1,2}) =:= <<1,2>>.
+             ">>,
+	   [],
+	   {errors,[{4,erl_lint,{undefined_function,{binary_part,2}}}],[]}},
+          %% but we could import it again...
+	  {clash10,
+           <<"-export([x/1]).
+              -compile({no_auto_import,[binary_part/2]}).
+              -import(erlang,[binary_part/2]).
+              x(X) ->
+                 binary_part(X,{1,2}) =:= <<1,2>>.
+             ">>,
+	   [],
+	   []},
+          %% and actually use it in a guard...
+	  {clash11,
+           <<"-export([x/1]).
+              -compile({no_auto_import,[binary_part/2]}).
+              -import(erlang,[binary_part/2]).
+              x(X) when binary_part(X,{0,1}) =:= <<0>> ->
+                 binary_part(X,{1,2}) =:= <<1,2>>.
+             ">>,
+	   [],
+	   []},
+          %% but for non-obvious historical reasons, imported functions cannot be used in
+	  %% fun construction without the module name...
+	  {clash12,
+           <<"-export([x/1]).
+              -compile({no_auto_import,[binary_part/2]}).
+              -import(erlang,[binary_part/2]).
+              x(X) when binary_part(X,{0,1}) =:= <<0>> ->
+                 binary_part(X,{1,2}) =:= fun binary_part/2.
+             ">>,
+	   [],
+	   {errors,[{5,erl_lint,{undefined_function,{binary_part,2}}}],[]}},
+          %% Not from erlang and not from anywhere else
+	  {clash13,
+           <<"-export([x/1]).
+              -compile({no_auto_import,[binary_part/2]}).
+              -import(x,[binary_part/2]).
+              x(X) ->
+                 binary_part(X,{1,2}) =:= fun binary_part/2.
+             ">>,
+	   [],
+	   {errors,[{5,erl_lint,{undefined_function,{binary_part,2}}}],[]}},
+	  %% ...while real auto-import is OK.
+	  {clash14,
+           <<"-export([x/1]).
+              x(X) when binary_part(X,{0,1}) =:= <<0>> ->
+                 binary_part(X,{1,2}) =:= fun binary_part/2.
+             ">>,
+	   [],
+	   []},
+          %% Import directive clashing with old bif is an error, regardless of if it's called or not
+	  {clash15,
+           <<"-export([x/1]).
+              -import(x,[abs/1]).
+              x(X) ->
+                 binary_part(X,{1,2}).
+             ">>,
+	   [],
+	   {errors,[{2,erl_lint,{redefine_old_bif_import,{abs,1}}}],[]}},
+	  %% For a new BIF, it's only a warning
+	  {clash16,
+           <<"-export([x/1]).
+              -import(x,[binary_part/3]).
+              x(X) ->
+                 abs(X).
+             ">>,
+	   [],
+	   {warnings,[{2,erl_lint,{redefine_bif_import,{binary_part,3}}}]}},
+	  %% And, you cannot redefine already imported things that aren't auto-imported
+	  {clash17,
+           <<"-export([x/1]).
+              -import(x,[binary_port/3]).
+              -import(y,[binary_port/3]).
+              x(X) ->
+                 abs(X).
+             ">>,
+	   [],
+	   {errors,[{3,erl_lint,{redefine_import,{{binary_port,3},x}}}],[]}},
+	  %% Not with local functions either
+	  {clash18,
+           <<"-export([x/1]).
+              -import(x,[binary_port/3]).
+              binary_port(A,B,C) ->
+                 binary_part(A,B,C).
+              x(X) ->
+                 abs(X).
+             ">>,
+	   [],
+	   {errors,[{3,erl_lint,{define_import,{binary_port,3}}}],[]}},
+	  %% Like clash8: Dont accept a guard if it's explicitly module-name called either
+	  {clash19,
+           <<"-export([binary_port/3]).
+              -compile({no_auto_import,[binary_part/3]}).
+              -import(x,[binary_part/3]).
+              binary_port(A,B,C) when x:binary_part(A,B,C) ->
+                 binary_part(A,B,C+1).
+             ">>,
+	   [],
+	   {errors,[{4,erl_lint,illegal_guard_expr}],[]}}
+	 ],
 
     ?line [] = run(Config, Ts),
     ok.