Treat modules with --no-debug-info as uncached, closes #15159

Additionally make sure --debug-info is part of the cache key.

Author: josevalim

lib/elixir/lib/module/parallel_checker.ex

@@ -105,7 +105,7 @@ defmodule Module.ParallelChecker do
                        {@elixir_checker_version, contents} <- :erlang.binary_to_term(checker) do
                     {cache_chunk(table, module, contents), module_map_to_module_tuple(module_map)}
                   else
-                    _ -> {:not_found, nil}
+                    _ -> {:uncached, nil}
                   end
 
                 is_tuple(info) ->

lib/mix/lib/mix/tasks/compile.elixir.ex

@@ -63,7 +63,8 @@ defmodule Mix.Tasks.Compile.Elixir do
     * `--all-warnings` (`--no-all-warnings`) - prints all warnings, including previous compilations
       (default is true except on errors)
     * `--docs` (`--no-docs`) - attaches (or not) documentation to compiled modules
-    * `--debug-info` (`--no-debug-info`) - attaches (or not) debug info to compiled modules
+    * `--debug-info` (`--no-debug-info`) - attaches (or not) debug info to compiled modules.
+      Passing this flag will force a full recompilation
     * `--force` - forces compilation regardless of modification times
     * `--ignore-module-conflict` - does not emit warnings if a module was previously defined
     * `--long-compilation-threshold N` - sets the "long compilation" threshold
@@ -73,9 +74,9 @@ defmodule Mix.Tasks.Compile.Elixir do
     * `--no-verification` - disables code verification, such as unused functions,
       deprecation warnings, and type checking. It must be used solely for debugging
       alongside `MIX_DEBUG=1`
-    * `--no-check-cwd` - (since v1.19.2) Elixir stores absolute paths in .beam files, which means
-      that relocating the project root triggers a full build. Pass this option if you don't want
-      the current working directory to be checked
+    * `--no-check-cwd` - (since v1.19.2) Elixir stores absolute paths in .beam files,
+      which means that relocating the project root triggers a full build. Pass this option
+      if you don't want the current working directory to be checked
     * `--purge-consolidation-path-if-stale PATH` - deletes and purges modules in the
       given protocol consolidation path if compilation is required
     * `--purge-compiler-modules` - automatically purge compilation modules
@@ -135,14 +136,17 @@ defmodule Mix.Tasks.Compile.Elixir do
 
     manifest = manifest()
     base = xref_exclude_opts(project[:elixirc_options] || [], project)
-    cache_key = {base, srcs, "--no-optional-deps" in args}
 
     opts =
       base
       |> Keyword.merge(opts)
       |> tracers_opts(tracers)
       |> profile_opts()
 
+    # Optional dependencies and debug info affect how artifacts are generated
+    cache_key =
+      {base, srcs, "--no-optional-deps" in args, "--no-debug-info" in args}
+
     opts =
       if "--no-protocol-consolidation" in args do
         # TODO: Deprecate me on Elixir v1.23

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

@@ -73,7 +73,7 @@ defmodule Mix.Tasks.Compile do
     * `--no-listeners` - does not start Mix listeners
     * `--no-optional-deps` - does not compile or load optional deps. Useful for testing
       if a library still successfully compiles without optional dependencies (which is the
-      default case with dependencies)
+      default case with dependencies). Passing this flag will force a full recompilation
     * `--no-prune-code-paths` - do not prune code paths before compilation, this keeps
       the entirety of Erlang/OTP available when the project starts
     * `--no-protocol-consolidation` - skips protocol consolidation

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

@@ -322,6 +322,55 @@ defmodule Mix.Tasks.Compile.ElixirTest do
     :elixir_config.put(:initial_dbg_callback, {Macro, :dbg, []})
   end
 
+  test "recompiles files on debug_info flag" do
+    in_fixture("no_mixfile", fn ->
+      Mix.Project.push(MixTest.Case.Sample)
+
+      File.write!("lib/a.ex", """
+      defmodule DebugInfo.A do
+        def run, do: :ok
+      end
+      """)
+
+      File.write!("lib/b.ex", """
+      defmodule DebugInfo.B do
+        def run, do: DebugInfo.A.run()
+      end
+      """)
+
+      File.write!("lib/c.ex", """
+      defmodule DebugInfo.C do
+        @compile_time_value DebugInfo.A.run()
+        def compile_time_value, do: @compile_time_value
+        def run, do: DebugInfo.B.run()
+      end
+      """)
+
+      assert Mix.Tasks.Compile.Elixir.run(["--verbose"]) == {:ok, []}
+      assert_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
+      assert_received {:mix_shell, :info, ["Compiled lib/b.ex"]}
+      assert_received {:mix_shell, :info, ["Compiled lib/c.ex"]}
+
+      assert Mix.Tasks.Compile.Elixir.run(["--verbose", "--no-debug-info"]) == {:ok, []}
+      assert_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
+      assert_received {:mix_shell, :info, ["Compiled lib/b.ex"]}
+      assert_received {:mix_shell, :info, ["Compiled lib/c.ex"]}
+
+      assert Mix.Tasks.Compile.Elixir.run(["--verbose", "--no-debug-info"]) == {:noop, []}
+
+      File.write!("lib/a.ex", """
+      defmodule DebugInfo.A do
+        def run, do: :error
+      end
+      """)
+
+      assert Mix.Tasks.Compile.Elixir.run(["--verbose", "--no-debug-info"]) == {:ok, []}
+      assert_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
+      refute_received {:mix_shell, :info, ["Compiled lib/b.ex"]}
+      assert_received {:mix_shell, :info, ["Compiled lib/c.ex"]}
+    end)
+  end
+
   test "recompiles files when config changes export dependencies" do
     in_fixture("no_mixfile", fn ->
       Mix.Project.push(MixTest.Case.Sample)