Fixes for Erlang/OTP 23

Author: josevalim

lib/elixir/lib/map.ex

@@ -265,8 +265,6 @@ defmodule Map do
 
       iex> Map.fetch!(%{a: 1}, :a)
       1
-      iex> Map.fetch!(%{a: 1}, :b)
-      ** (KeyError) key :b not found in: %{a: 1}
 
   """
   @spec fetch!(map, key) :: value

lib/elixir/src/elixir_erl.erl

@@ -54,13 +54,8 @@ definition_to_anonymous(Module, Kind, Meta, Clauses) ->
   {value, Result, _Binding} = erl_eval:expr(Fun, [], {value, LocalHandler}),
   Result.
 
-invoke_local(Module, RawName, Args) ->
-  %% If we have a macro, its arity in the table is
-  %% actually one less than in the function call
-  {Name, Arity} = case atom_to_list(RawName) of
-    "MACRO-" ++ Rest -> {list_to_atom(Rest), length(Args) - 1};
-    _ -> {RawName, length(Args)}
-  end,
+invoke_local(Module, ErlName, Args) ->
+  {Name, Arity} = elixir_utils:erl_fa_to_elixir_fa(ErlName, length(Args)),
 
   case elixir_def:local_for(Module, Name, Arity, all) of
     false ->

lib/elixir/src/elixir_erl_compiler.erl

@@ -134,6 +134,14 @@ custom_format(sys_core_fold, {eval_failure, Error}) ->
   #{'__struct__' := Struct} = 'Elixir.Exception':normalize(error, Error),
   ["this expression will fail with ", elixir_aliases:inspect(Struct)];
 
+custom_format(sys_core_fold, {nomatch_shadow,Line,{ErlName,ErlArity}}) ->
+  {Name, Arity} = elixir_utils:erl_fa_to_elixir_fa(ErlName, ErlArity),
+
+  io_lib:format(
+    "this clause for ~ts/~B cannot match because a previous clause at line ~B always matches",
+    [Name, Arity, Line]
+  );
+
 custom_format([], Desc) ->
   io_lib:format("~p", [Desc]);
 

lib/elixir/src/elixir_utils.erl

@@ -7,15 +7,19 @@
   read_file_type/1, read_file_type/2, read_link_type/1, read_posix_mtime_and_size/1,
   change_posix_time/2, change_universal_time/2,
   guard_op/2, extract_splat_guards/1, extract_guards/1,
-  erlang_comparison_op_to_elixir/1]).
+  erlang_comparison_op_to_elixir/1, erl_fa_to_elixir_fa/2]).
 -include("elixir.hrl").
 -include_lib("kernel/include/file.hrl").
 
-% Builds the macro name
-
 macro_name(Macro) ->
   list_to_atom("MACRO-" ++ atom_to_list(Macro)).
 
+erl_fa_to_elixir_fa(Name, Arity) ->
+  case atom_to_list(Name) of
+    "MACRO-" ++ Rest -> {list_to_atom(Rest), Arity - 1};
+    _ -> {Name, Arity}
+  end.
+
 guard_op('andalso', 2) ->
   true;
 guard_op('orelse', 2) ->

lib/elixir/test/elixir/kernel/parallel_compiler_test.exs

@@ -288,8 +288,7 @@ defmodule Kernel.ParallelCompilerTest do
             assert {:error, [error], []} =
                      Kernel.ParallelCompiler.compile_to_path([fixture], output)
 
-            msg = "this clause cannot match because a previous clause at line 2 always matches"
-            assert error == {fixture, 3, msg}
+            assert {^fixture, 3, "this clause " <> _} = error
           end)
 
         assert msg =~
@@ -434,10 +433,7 @@ defmodule Kernel.ParallelCompilerTest do
           capture_io(:stderr, fn ->
             assert {:error, [error], []} = Kernel.ParallelCompiler.require([fixture])
 
-            message =
-              "this clause cannot match because a previous clause at line 2 always matches"
-
-            assert error == {fixture, 3, message}
+            assert {^fixture, 3, "this clause " <> _} = error
           end)
 
         assert msg =~

lib/elixir/test/elixir/kernel/warning_test.exs

@@ -661,24 +661,6 @@ defmodule Kernel.WarningTest do
     purge(Sample)
   end
 
-  test "previous clause always matches" do
-    assert capture_err(fn ->
-             Code.eval_string("""
-             defmodule Sample do
-               def binary_cond do
-                 v = "bc"
-                 cond do
-                   is_binary(v) -> :bin
-                   true -> :ok
-                 end
-               end
-             end
-             """)
-           end) =~ "this clause cannot match because a previous clause at line 5 always matches"
-  after
-    purge(Sample)
-  end
-
   test "late function heads" do
     assert capture_err(fn ->
              Code.eval_string("""
@@ -740,7 +722,8 @@ defmodule Kernel.WarningTest do
                def hello, do: nil
              end
              """)
-           end) =~ "this clause cannot match because a previous clause at line 2 always matches"
+           end) =~
+             ~r"this clause( for hello/0)? cannot match because a previous clause at line 2 always matches"
   after
     purge(Sample)
   end
@@ -760,7 +743,8 @@ defmodule Kernel.WarningTest do
                use Sample
              end
              """)
-           end) =~ "this clause cannot match because a previous clause at line 10 always matches"
+           end) =~
+             ~r"this clause( for hello/0)? cannot match because a previous clause at line 10 always matches"
   after
     purge(Sample)
     purge(UseSample)
@@ -1628,7 +1612,8 @@ defmodule Kernel.WarningTest do
                defguard foo(baz) when baz == :baz
              end
              """)
-           end) =~ "this clause cannot match because a previous clause at line 2 always matches"
+           end) =~
+             ~r"this clause( for foo/1)? cannot match because a previous clause at line 2 always matches"
   after
     purge(Sample)
   end
@@ -1641,7 +1626,8 @@ defmodule Kernel.WarningTest do
                defmacro foo(bar), do: bar == :bar
              end
              """)
-           end) =~ "this clause cannot match because a previous clause at line 2 always matches"
+           end) =~
+             ~r"this clause( for foo/1)? cannot match because a previous clause at line 2 always matches"
   after
     purge(Sample)
   end