Ensure yecc is available to emit warnings, closes #12691

Author: josevalim

lib/mix/lib/mix/compilers/erlang.ex

@@ -4,20 +4,23 @@ defmodule Mix.Compilers.Erlang do
   @manifest_vsn 1
 
   @doc """
-  Compiles the files in `mappings` with given extensions into
-  the destination, automatically invoking the callback for each
-  stale input and output pair (or for all if `force` is `true`) and
-  removing files that no longer have a source, while keeping the
-  `manifest` up to date.
+  Compiles the given `mappings`.
 
-  `mappings` should be a list of tuples in the form of `{src, dest}` paths.
+  `mappings` is a list of `{src, dest}` pairs, where the source
+  extensions are compiled into the destination extension,
+  automatically invoking the callback for each stale pair (or for
+  all if `force` is `true`) and removing files that no longer have
+  a source, while keeping the `manifest` up to date.
 
   ## Options
 
     * `:force` - forces compilation regardless of modification times
 
     * `:parallel` - a mapset of files to compile in parallel
 
+    * `:preload` - any code that must be preloaded if any pending
+      entry needs to be compiled
+
   ## Examples
 
   For example, a simple compiler for Lisp Flavored Erlang
@@ -54,22 +57,25 @@ defmodule Mix.Compilers.Erlang do
   def compile(manifest, mappings, src_ext, dest_ext, opts, callback) when is_list(opts) do
     force = opts[:force]
 
-    files =
+    entries =
       for {src, dest} <- mappings,
-          target <- extract_targets(src, src_ext, dest, dest_ext, force),
+          target <- extract_entries(src, src_ext, dest, dest_ext, force),
           do: target
 
-    compile(manifest, files, src_ext, opts, callback)
+    if preload = entries != [] && opts[:preload] do
+      preload.()
+    end
+
+    compile(manifest, entries, src_ext, opts, callback)
   end
 
   @doc """
-  Compiles the given `mappings`.
+  Compiles the given `entries`.
 
-  `mappings` should be a list of tuples in the form of `{src, dest}`.
+  `entries` are a list of `{:ok | :stale, src, dest}` tuples.
 
-  A `manifest` file and a `callback` to be invoked for each src/dest pair
-  must be given. A src/dest pair where destination is `nil` is considered
-  to be up to date and won't be (re-)compiled.
+  A `manifest` file and a `callback` to be invoked for each stale
+  src/dest pair must also be given.
 
   ## Options
 
@@ -78,8 +84,8 @@ defmodule Mix.Compilers.Erlang do
     * `:parallel` - a mapset of files to compile in parallel
 
   """
-  def compile(manifest, mappings, opts \\ [], callback) do
-    compile(manifest, mappings, :erl, opts, callback)
+  def compile(manifest, entries, opts \\ [], callback) do
+    compile(manifest, entries, :erl, opts, callback)
   end
 
   defp compile(manifest, mappings, ext, opts, callback) do
@@ -102,7 +108,7 @@ defmodule Mix.Compilers.Erlang do
     # Clear stale and removed files from manifest
     entries =
       Enum.reject(entries, fn {dest, _warnings} ->
-        dest in removed || Enum.any?(stale, fn {_, stale_dest} -> dest == stale_dest end)
+        dest in removed || List.keymember?(stale, dest, 1)
       end)
 
     if Keyword.get(opts, :all_warnings, true), do: show_warnings(entries)
@@ -156,9 +162,8 @@ defmodule Mix.Compilers.Erlang do
     end
   end
 
-  @doc """
-  Ensures the native OTP application is available.
-  """
+  # TODO: Deprecate this in favor of `Mix.ensure_application!/1` in Elixir v1.19.
+  @doc false
   def ensure_application!(app, _input) do
     Mix.ensure_application!(app)
     {:ok, _} = Application.ensure_all_started(app)
@@ -202,7 +207,7 @@ defmodule Mix.Compilers.Erlang do
     manifest |> read_manifest() |> Enum.map(&elem(&1, 0))
   end
 
-  defp extract_targets(src_dir, src_ext, dest_dir, dest_ext, force) do
+  defp extract_entries(src_dir, src_ext, dest_dir, dest_ext, force) do
     files = Mix.Utils.extract_files(List.wrap(src_dir), List.wrap(src_ext))
 
     for file <- files do

lib/mix/lib/mix/tasks/compile.leex.ex

@@ -53,15 +53,19 @@ defmodule Mix.Tasks.Compile.Leex do
       Mix.raise(":leex_options should be a list of options, got: #{inspect(options)}")
     end
 
-    opts = [parallel: true] ++ opts
+    opts = [parallel: true, preload: &preload/0] ++ opts
 
     Erlang.compile(manifest(), mappings, :xrl, :erl, opts, fn input, output ->
-      Erlang.ensure_application!(:parsetools, input)
       options = options ++ @forced_opts ++ [scannerfile: Erlang.to_erl_file(output)]
       :leex.file(Erlang.to_erl_file(input), options)
     end)
   end
 
+  defp preload do
+    Mix.ensure_application!(:parsetools)
+    {:ok, _} = Application.ensure_all_started(:parsetools)
+  end
+
   @impl true
   def manifests, do: [manifest()]
   defp manifest, do: Path.join(Mix.Project.manifest_path(), @manifest)

lib/mix/lib/mix/tasks/compile.yecc.ex

@@ -53,15 +53,19 @@ defmodule Mix.Tasks.Compile.Yecc do
       Mix.raise(":yecc_options should be a list of options, got: #{inspect(options)}")
     end
 
-    opts = [parallel: true] ++ opts
+    opts = [parallel: true, preload: &preload/0] ++ opts
 
     Erlang.compile(manifest(), mappings, :yrl, :erl, opts, fn input, output ->
-      Erlang.ensure_application!(:parsetools, input)
       options = options ++ @forced_opts ++ [parserfile: Erlang.to_erl_file(output)]
       :yecc.file(Erlang.to_erl_file(input), options)
     end)
   end
 
+  defp preload do
+    Mix.ensure_application!(:parsetools)
+    {:ok, _} = Application.ensure_all_started(:parsetools)
+  end
+
   @impl true
   def manifests, do: [manifest()]
   defp manifest, do: Path.join(Mix.Project.manifest_path(), @manifest)

lib/mix/test/mix/tasks/compile.yecc_test.exs

@@ -60,6 +60,24 @@ defmodule Mix.Tasks.Compile.YeccTest do
                  severity: :warning
                } = diagnostic
       end)
+
+      # Removing parse tools re-add it later even if only to show warnings
+      :code.del_path(:parsetools)
+      :code.delete(:yecc)
+      :code.purge(:yecc)
+      refute Code.ensure_loaded?(:yecc)
+
+      capture_io(fn ->
+        assert {:noop, [diagnostic]} = Mix.Tasks.Compile.Yecc.run([])
+
+        assert %Mix.Task.Compiler.Diagnostic{
+                 compiler_name: "yecc",
+                 file: ^file,
+                 message: "conflicts: 1 shift/reduce, 0 reduce/reduce",
+                 position: 0,
+                 severity: :warning
+               } = diagnostic
+      end)
     end)
   end