Keep stacktrace in diagnostics

9 files changed, 173 insertions, 128 deletions

diff --git a/lib/elixir/lib/calendar/datetime.ex b/lib/elixir/lib/calendar/datetime.ex
index 44d74dee3..83dd5d801 100644
--- a/lib/elixir/lib/calendar/datetime.ex
+++ b/lib/elixir/lib/calendar/datetime.ex
@@ -169,7 +169,7 @@ defmodule DateTime do
         utc_now(unit, Calendar.ISO)
 
       calendar ->
-        utc_now(:native, calendar)
+        System.os_time() |> from_unix!(:native, calendar)
     end
   end
 
diff --git a/lib/elixir/lib/io.ex b/lib/elixir/lib/io.ex
index a6ba705de..d055b4d86 100644
--- a/lib/elixir/lib/io.ex
+++ b/lib/elixir/lib/io.ex
@@ -325,15 +325,14 @@ defmodule IO do
           :ok
   def warn(message, stacktrace_info)
 
-  def warn(message, []) do
-    message = [to_chardata(message), ?\n]
-    :elixir_errors.print_diagnostic(:warning, 0, nil, message, message)
-  end
-
   def warn(message, %Macro.Env{} = env) do
     warn(message, Macro.Env.stacktrace(env))
   end
 
+  def warn(message, []) do
+    :elixir_errors.emit_diagnostic(:warning, 0, nil, to_chardata(message), [])
+  end
+
   def warn(message, [{_, _} | _] = keyword) do
     if file = keyword[:file] do
       warn(
@@ -353,17 +352,10 @@ defmodule IO do
 
   def warn(message, [{_, _, _, opts} | _] = stacktrace) do
     message = to_chardata(message)
-    formatted_trace = Enum.map_join(stacktrace, "\n  ", &Exception.format_stacktrace_entry(&1))
     line = opts[:line]
     file = opts[:file]
-
-    :elixir_errors.print_diagnostic(
-      :warning,
-      line || 0,
-      file && List.to_string(file),
-      message,
-      [message, ?\n, "  ", formatted_trace, ?\n]
-    )
+    file = file && List.to_string(file)
+    :elixir_errors.emit_diagnostic(:warning, line || 0, file, message, stacktrace)
   end
 
   @doc false
diff --git a/lib/elixir/lib/kernel/parallel_compiler.ex b/lib/elixir/lib/kernel/parallel_compiler.ex
index 7b8c88e0b..fc9a512d1 100644
--- a/lib/elixir/lib/kernel/parallel_compiler.ex
+++ b/lib/elixir/lib/kernel/parallel_compiler.ex
@@ -11,7 +11,8 @@ defmodule Kernel.ParallelCompiler do
           file: Path.t(),
           severity: severity,
           message: String.t(),
-          position: position
+          position: position,
+          stacktrace: Exception.stacktrace()
         }
 
   @type info :: %{
@@ -175,14 +176,14 @@ defmodule Kernel.ParallelCompiler do
   Prints a diagnostic returned by the compiler into stderr.
   """
   @doc since: "1.15.0"
-  def print_diagnostic(%{file: file, position: position, message: message, severity: severity}) do
-    :elixir_errors.print_diagnostic_no_capture(severity, position, file, message)
+  def print_diagnostic(diagnostic) do
+    :elixir_errors.print_diagnostic(diagnostic)
   end
 
   @doc false
   # TODO: Deprecate me on Elixir v1.19
   def print_warning({file, location, warning}) do
-    :elixir_errors.print_diagnostic_no_capture(:warning, location, file, warning)
+    :elixir_errors.print_warning(location, file, warning)
   end
 
   @doc false
@@ -802,7 +803,7 @@ defmodule Kernel.ParallelCompiler do
         description = "deadlocked waiting on #{kind} #{inspect(on)}"
         error = CompileError.exception(description: description, file: nil, line: nil)
         print_error(file, :error, error, stacktrace)
-        {Path.relative_to_cwd(file), on, description}
+        {Path.relative_to_cwd(file), on, description, stacktrace}
       end
 
     IO.puts(:stderr, """
@@ -816,7 +817,7 @@ defmodule Kernel.ParallelCompiler do
       |> Enum.map(&(&1 |> elem(0) |> String.length()))
       |> Enum.max()
 
-    for {file, mod, _} <- deadlock do
+    for {file, mod, _, _} <- deadlock do
       IO.puts(:stderr, ["  ", String.pad_leading(file, max), " => " | inspect(mod)])
     end
 
@@ -826,8 +827,14 @@ defmodule Kernel.ParallelCompiler do
         "and that the modules they reference exist and are correctly named\n"
     )
 
-    for {file, _, description} <- deadlock do
-      %{severity: :error, file: Path.absname(file), position: nil, message: description}
+    for {file, _, description, stacktrace} <- deadlock do
+      %{
+        severity: :error,
+        file: Path.absname(file),
+        position: nil,
+        message: description,
+        stacktrace: stacktrace
+      }
     end
   end
 
@@ -854,7 +861,7 @@ defmodule Kernel.ParallelCompiler do
     line = get_line(file, reason, stack)
     file = Path.absname(file)
     message = :unicode.characters_to_binary(Kernel.CLI.format_error(kind, reason, stack))
-    %{file: file, position: line || 0, message: message, severity: :error}
+    %{file: file, position: line || 0, message: message, severity: :error, stacktrace: stack}
   end
 
   defp get_line(_file, %{line: line, column: column}, _stack)
diff --git a/lib/elixir/lib/module/parallel_checker.ex b/lib/elixir/lib/module/parallel_checker.ex
index 2e52a6b98..20f146931 100644
--- a/lib/elixir/lib/module/parallel_checker.ex
+++ b/lib/elixir/lib/module/parallel_checker.ex
@@ -291,46 +291,48 @@ defmodule Module.ParallelChecker do
   def emit_warnings(warnings) do
     Enum.flat_map(warnings, fn {module, warning, locations} ->
       message = module.format_warning(warning)
-
-      :elixir_errors.print_diagnostic_no_capture(
-        :warning,
-        [message, ?\n, format_locations(locations)]
-      )
-
-      Enum.map(locations, fn {file, line, _mfa} ->
-        %{severity: :warning, file: file, position: line, message: message}
-      end)
+      diagnostics = Enum.map(locations, &to_diagnostic(message, &1))
+      :elixir_errors.print_warning([message, ?\n, format_stacktraces(diagnostics)])
+      diagnostics
     end)
   end
 
-  defp format_locations([location]) do
-    format_location(location)
+  defp format_stacktraces([diagnostic]) do
+    format_diagnostic_stacktrace(diagnostic)
   end
 
-  defp format_locations(locations) do
+  defp format_stacktraces(diagnostics) do
     [
-      "Invalid call found at #{length(locations)} locations:\n",
-      Enum.map(locations, &format_location/1)
+      "Invalid call found at #{length(diagnostics)} locations:\n",
+      Enum.map(diagnostics, &format_diagnostic_stacktrace/1)
     ]
   end
 
-  defp format_location({file, line, {module, fun, arity}}) do
-    mfa = Exception.format_mfa(module, fun, arity)
-    [format_file_line(file, line), ": ", mfa, ?\n]
+  defp format_diagnostic_stacktrace(%{stacktrace: [stacktrace]}) do
+    ["  ", Exception.format_stacktrace_entry(stacktrace), ?\n]
   end
 
-  defp format_location({file, line, nil}) do
-    [format_file_line(file, line), ?\n]
+  defp to_diagnostic(message, {file, line, mfa}) do
+    %{
+      severity: :warning,
+      file: file,
+      position: line,
+      message: message,
+      stacktrace: [to_stacktrace(file, line, mfa)]
+    }
   end
 
-  defp format_location({file, line, module}) do
-    [format_file_line(file, line), ": ", inspect(module), ?\n]
-  end
+  defp to_stacktrace(file, line, {module, fun, arity}),
+    do: {module, fun, arity, location(file, line)}
+
+  defp to_stacktrace(file, line, nil),
+    do: {:elixir_compiler, :__FILE__, 1, location(file, line)}
+
+  defp to_stacktrace(file, line, module),
+    do: {module, :__MODULE__, 0, location(file, line)}
 
-  defp format_file_line(file, line) do
-    file = Path.relative_to_cwd(file)
-    line = if line > 0, do: [?: | Integer.to_string(line)], else: []
-    ["  ", file, line]
+  defp location(file, line) do
+    [file: String.to_charlist(Path.relative_to_cwd(file)), line: line]
   end
 
   ## Cache
diff --git a/lib/elixir/src/elixir_errors.erl b/lib/elixir/src/elixir_errors.erl
index 758fffb67..4a907f207 100644
--- a/lib/elixir/src/elixir_errors.erl
+++ b/lib/elixir/src/elixir_errors.erl
@@ -7,35 +7,61 @@
 -export([compile_error/1, compile_error/3, parse_error/5]).
 -export([function_error/4, module_error/4, file_error/4]).
 -export([erl_warn/3, file_warn/4]).
--export([print_diagnostic/5, print_diagnostic_no_capture/2, print_diagnostic_no_capture/4]).
+-export([print_diagnostic/1, emit_diagnostic/5]).
+-export([print_warning/1, print_warning/3]).
 -include("elixir.hrl").
 -type location() :: non_neg_integer() | {non_neg_integer(), non_neg_integer()}.
 
-%% Low-level warning, should be used only from Erlang passes.
--spec erl_warn(location() | none, unicode:chardata(), unicode:chardata()) -> ok.
-erl_warn(none, File, Warning) ->
-  erl_warn(0, File, Warning);
-erl_warn(Location, File, Warning) when is_binary(File) ->
-  send_diagnostic(warning, Location, File, Warning),
-  print_diagnostic_no_capture(warning, Location, File, Warning).
+%% Diagnostic API
+
+%% TODO: Remove me on Elixir v2.0.
+print_warning(Location, File, Message) ->
+  print_warning([Message, file_format(Location, File), $\n]).
+
+%% Used by parallel checker as it groups warnings.
+print_warning(Message) ->
+  io:put_chars(standard_error, [prefix(warning), Message, $\n]).
 
--spec print_diagnostic_no_capture(warning | error, location(), unicode:chardata(), unicode:chardata()) -> ok.
-print_diagnostic_no_capture(Type, Location, File, Message) ->
-  print_diagnostic_no_capture(Type, [Message, "\n  ", file_format(Location, File), $\n]).
+print_diagnostic(#{severity := Severity, message := Message, stacktrace := Stacktrace} = Diagnostic) ->
+  Location =
+    case (Stacktrace =:= []) orelse elixir_config:is_bootstrap() of
+      true ->
+        #{position := Position, file := File} = Diagnostic,
+        file_format(Position, File);
 
--spec print_diagnostic_no_capture(warning | error, unicode:chardata()) -> ok.
-print_diagnostic_no_capture(Type, Message) ->
-  io:put_chars(standard_error, [prefix(Type), Message, $\n]),
+      false ->
+        [["\n  ", 'Elixir.Exception':format_stacktrace_entry(E)] || E <- Stacktrace]
+    end,
+  io:put_chars(standard_error, [prefix(Severity), Message, Location, "\n\n"]),
   ok.
 
--spec print_diagnostic(warning | error, location(), unicode:chardata() | nil, unicode:chardata(), unicode:chardata()) -> ok.
-print_diagnostic(Type, Location, File, DiagMessage, PrintMessage)
-    when is_binary(File) or (File == nil) ->
-  send_diagnostic(Type, Location, File, DiagMessage),
-  print_diagnostic_no_capture(Type, PrintMessage).
+emit_diagnostic(Severity, Position, File, Message, Stacktrace) ->
+  Diagnostic = #{
+    severity => Severity,
+    file => if File =:= nil -> nil; true -> filename:absname(File) end,
+    position => Position,
+    message => unicode:characters_to_binary(Message),
+    stacktrace => Stacktrace
+  },
+
+  print_diagnostic(Diagnostic),
+
+  case get(elixir_compiler_info) of
+    undefined -> ok;
+    {CompilerPid, _} -> CompilerPid ! {diagnostic, Diagnostic}
+  end,
+
+  ok.
 
 %% Compilation error/warn handling.
 
+%% Low-level warning, should be used only from Erlang passes.
+-spec erl_warn(location() | none, unicode:chardata(), unicode:chardata()) -> ok.
+erl_warn(none, File, Warning) ->
+  erl_warn(0, File, Warning);
+erl_warn(Location, File, Warning) when is_binary(File) ->
+  emit_diagnostic(warning, Location, File, Warning, []).
+
 -spec file_warn(list(), binary() | #{file := binary(), _ => _}, module(), any()) -> ok.
 file_warn(Meta, File, Module, Desc) when is_list(Meta), is_binary(File) ->
   file_warn(Meta, #{file => File}, Module, Desc);
@@ -44,9 +70,9 @@ file_warn(Meta, E, Module, Desc) when is_list(Meta) ->
   case elixir_config:is_bootstrap() of
     true -> ok;
     false ->
-      {EnvLine, EnvFile, EnvLocation} = env_format(Meta, E),
+      {EnvLine, EnvFile, EnvStacktrace} = env_format(Meta, E),
       Message = Module:format_error(Desc),
-      print_diagnostic(warning, EnvLine, EnvFile, Message, [Message, "\n  ", EnvLocation, $\n])
+      emit_diagnostic(warning, EnvLine, EnvFile, Message, EnvStacktrace)
   end.
 
 -spec file_error(list(), binary() | #{file := binary(), _ => _}, module(), any()) -> no_return().
@@ -77,9 +103,9 @@ function_error(Meta, Env, Module, Desc) ->
   file_error(Meta, Env, Module, Desc).
 
 print_error(Meta, Env, Module, Desc) ->
-  {EnvLine, EnvFile, EnvLocation} = env_format(Meta, Env),
+  {EnvLine, EnvFile, EnvStacktrace} = env_format(Meta, Env),
   Message = Module:format_error(Desc),
-  print_diagnostic(error, EnvLine, EnvFile, Message, [Message, "\n  ", EnvLocation, $\n]),
+  emit_diagnostic(error, EnvLine, EnvFile, Message, EnvStacktrace),
   ok.
 
 %% Compilation error.
@@ -94,11 +120,11 @@ compile_error(#{file := File}) ->
 
 -spec compile_error(list(), binary(), binary() | unicode:charlist()) -> no_return().
 compile_error(Meta, File, Message) when is_binary(Message) ->
-  MetaLocation = meta_location(Meta, File),
-  raise('Elixir.CompileError', Message, MetaLocation);
+  {File, Line} = meta_location(Meta, File),
+  raise('Elixir.CompileError', Message, [{file, File}, {line, Line}]);
 compile_error(Meta, File, Message) when is_list(Message) ->
-  MetaLocation = meta_location(Meta, File),
-  raise('Elixir.CompileError', elixir_utils:characters_to_binary(Message), MetaLocation).
+  {File, Line} = meta_location(Meta, File),
+  raise('Elixir.CompileError', elixir_utils:characters_to_binary(Message), [{file, File}, {line, Line}]).
 
 %% Tokenization parsing/errors.
 
@@ -210,21 +236,6 @@ snippet(InputString, Location, StartLine, StartColumn) ->
 
 %% Helpers
 
-send_diagnostic(Severity, Position, File, Message) ->
-  case get(elixir_compiler_info) of
-    undefined -> ok;
-    {CompilerPid, _} ->
-      Diagnostic = #{
-        severity => Severity,
-        file => if File =:= nil -> nil; true -> filename:absname(File) end,
-        position => Position,
-        message => unicode:characters_to_binary(Message)
-      },
-
-      CompilerPid ! {diagnostic, Diagnostic}
-  end,
-  ok.
-
 prefix(warning) ->
   case application:get_env(elixir, ansi_enabled, false) of
     true -> <<"\e[33mwarning: \e[0m">>;
@@ -237,33 +248,35 @@ prefix(error) ->
   end.
 
 env_format(Meta, #{file := EnvFile} = E) ->
-  [{file, File}, {line, Line}] = meta_location(Meta, EnvFile),
+  {File, Line} = meta_location(Meta, EnvFile),
 
-  Location =
+  Stacktrace =
     case E of
       #{function := {Name, Arity}, module := Module} ->
-        [file_format(Line, File), ": ", 'Elixir.Exception':format_mfa(Module, Name, Arity)];
+        [{Module, Name, Arity, [{file, elixir_utils:relative_to_cwd(File)}, {line, Line}]}];
       #{module := Module} when Module /= nil ->
-        [file_format(Line, File), ": ", elixir_aliases:inspect(Module)];
+        [{Module, '__MODULE__', 0, [{file, elixir_utils:relative_to_cwd(File)}, {line, Line}]}];
       #{} ->
-        file_format(Line, File)
+        []
     end,
 
-  {Line, File, Location}.
+  {Line, File, Stacktrace}.
 
+file_format(_, nil) ->
+  "";
 file_format({0, _Column}, File) ->
-  elixir_utils:relative_to_cwd(File);
+  ["\n  ", elixir_utils:relative_to_cwd(File)];
 file_format({Line, Column}, File) ->
-  io_lib:format("~ts:~w:~w", [elixir_utils:relative_to_cwd(File), Line, Column]);
+  io_lib:format("\n  ~ts:~w:~w", [elixir_utils:relative_to_cwd(File), Line, Column]);
 file_format(0, File) ->
-  elixir_utils:relative_to_cwd(File);
+  ["\n  ", elixir_utils:relative_to_cwd(File)];
 file_format(Line, File) ->
-  io_lib:format("~ts:~w", [elixir_utils:relative_to_cwd(File), Line]).
+  io_lib:format("\n  ~ts:~w", [elixir_utils:relative_to_cwd(File), Line]).
 
 meta_location(Meta, File) ->
   case elixir_utils:meta_keep(Meta) of
-    {F, L} -> [{file, F}, {line, L}];
-    nil    -> [{file, File}, {line, ?line(Meta)}]
+    {F, L} -> {F, L};
+    nil    -> {File, ?line(Meta)}
   end.
 
 raise(Kind, Message, Opts) when is_binary(Message) ->
diff --git a/lib/elixir/test/elixir/module/types/integration_test.exs b/lib/elixir/test/elixir/module/types/integration_test.exs
index 4414ea230..e835ac651 100644
--- a/lib/elixir/test/elixir/module/types/integration_test.exs
+++ b/lib/elixir/test/elixir/module/types/integration_test.exs
@@ -717,7 +717,7 @@ defmodule Module.Types.IntegrationTest do
 
       warning = """
       warning: A.a/0 is deprecated. oops
-        b.ex:3: B
+        b.ex:3: B (module)
 
       """
 
diff --git a/lib/mix/lib/mix/compilers/elixir.ex b/lib/mix/lib/mix/compilers/elixir.ex
index c4a48742a..c53d5f109 100644
--- a/lib/mix/lib/mix/compilers/elixir.ex
+++ b/lib/mix/lib/mix/compilers/elixir.ex
@@ -703,7 +703,8 @@ defmodule Mix.Compilers.Elixir do
         file: file,
         position: position,
         message: message,
-        compiler_name: "Elixir"
+        compiler_name: "Elixir",
+        stacktrace: []
       }
 
       if print? do
@@ -733,13 +734,20 @@ defmodule Mix.Compilers.Elixir do
     end
   end
 
-  defp diagnostic(%{file: file, position: position, message: message, severity: severity}) do
+  defp diagnostic(%{
+         file: file,
+         position: position,
+         message: message,
+         severity: severity,
+         stacktrace: stacktrace
+       }) do
     %Mix.Task.Compiler.Diagnostic{
       file: file,
       position: position,
       message: message,
       severity: severity,
-      compiler_name: "Elixir"
+      compiler_name: "Elixir",
+      stacktrace: stacktrace
     }
   end
 
diff --git a/lib/mix/lib/mix/task.compiler.ex b/lib/mix/lib/mix/task.compiler.ex
index ed4ed6125..dbaaeb0b7 100644
--- a/lib/mix/lib/mix/task.compiler.ex
+++ b/lib/mix/lib/mix/task.compiler.ex
@@ -39,7 +39,8 @@ defmodule Mix.Task.Compiler do
             message: IO.chardata(),
             position: position,
             compiler_name: String.t(),
-            details: any
+            details: any,
+            stacktrace: Exception.stacktrace()
           }
 
     @typedoc """
@@ -75,7 +76,15 @@ defmodule Mix.Task.Compiler do
             | {pos_integer, non_neg_integer, pos_integer, non_neg_integer}
 
     @enforce_keys [:file, :severity, :message, :position, :compiler_name]
-    defstruct [:file, :severity, :message, :position, :compiler_name, :details]
+    defstruct [
+      :file,
+      :severity,
+      :message,
+      :position,
+      :compiler_name,
+      details: nil,
+      stacktrace: []
+    ]
   end
 
   @type status :: :ok | :noop | :error
diff --git a/lib/mix/test/mix/tasks/compile.elixir_test.exs b/lib/mix/test/mix/tasks/compile.elixir_test.exs
index e18cefc00..06809ad4b 100644
--- a/lib/mix/test/mix/tasks/compile.elixir_test.exs
+++ b/lib/mix/test/mix/tasks/compile.elixir_test.exs
@@ -1390,23 +1390,35 @@ defmodule Mix.Tasks.Compile.ElixirTest do
       end
       """)
 
-      diagnostic = %Diagnostic{
-        file: Path.absname("lib/a.ex"),
-        severity: :warning,
-        position: 2,
-        compiler_name: "Elixir",
-        message:
-          "variable \"unused\" is unused (if the variable is not meant to be used, prefix it with an underscore)"
-      }
+      file = Path.absname("lib/a.ex")
+
+      message =
+        "variable \"unused\" is unused (if the variable is not meant to be used, prefix it with an underscore)"
 
       capture_io(:stderr, fn ->
-        assert {:ok, [^diagnostic]} = Mix.Tasks.Compile.Elixir.run([])
+        assert {:ok, [diagnostic]} = Mix.Tasks.Compile.Elixir.run([])
+
+        assert %Diagnostic{
+                 file: ^file,
+                 severity: :warning,
+                 position: 2,
+                 compiler_name: "Elixir",
+                 message: ^message
+               } = diagnostic
       end)
 
       # Recompiling should return :noop status because nothing is stale,
       # but also include previous warning diagnostics
       capture_io(:stderr, fn ->
-        assert {:noop, [^diagnostic]} = Mix.Tasks.Compile.Elixir.run([])
+        assert {:noop, [diagnostic]} = Mix.Tasks.Compile.Elixir.run([])
+
+        assert %Diagnostic{
+                 file: ^file,
+                 severity: :warning,
+                 position: 2,
+                 compiler_name: "Elixir",
+                 message: ^message
+               } = diagnostic
       end)
     end)
   end
@@ -1419,16 +1431,18 @@ defmodule Mix.Tasks.Compile.ElixirTest do
       IO.warn "warning", [{nil, nil, 0, file: 'lib/foo.txt', line: 3}]
       """)
 
-      diagnostic = %Diagnostic{
-        file: Path.absname("lib/foo.txt"),
-        severity: :warning,
-        position: 3,
-        compiler_name: "Elixir",
-        message: "warning"
-      }
+      file = Path.absname("lib/foo.txt")
 
       capture_io(:stderr, fn ->
-        assert {:ok, [^diagnostic]} = Mix.Tasks.Compile.Elixir.run([])
+        assert {:ok, [diagnostic]} = Mix.Tasks.Compile.Elixir.run([])
+
+        assert %Diagnostic{
+                 file: ^file,
+                 severity: :warning,
+                 position: 3,
+                 compiler_name: "Elixir",
+                 message: "warning"
+               } = diagnostic
       end)
     end)
   end