Deprecate Bundlex.platform/0, improve target detection for crosscompi…

…lator

README.md

@@ -31,7 +31,7 @@ defmodule MyApp.Mixfile do
 
   defp deps() do
     [
-      {:bundlex, "~> 1.4"}
+      {:bundlex, "~> 1.5"}
     ]
   end
 end

lib/bundlex.ex

@@ -9,7 +9,7 @@ defmodule Bundlex do
   @type platform_t :: :linux | :macosx | :windows32 | :windows64 | :nerves | :custom
 
   @typedoc """
-  A map containing four fields that describe the platform.
+  A map containing four fields that describe the target platform.
 
   It consists of:
   * architecture - e.g. `x86_64` or `arm64`
@@ -26,35 +26,53 @@ defmodule Bundlex do
           }
 
   @doc """
-  A function returning information about the target platform (unknown in case of crosscompilation).
+  A function returning information about the target platform. In case of cross-compilation the
+  information can be provided by setting appropriate environment variables.
   """
   @spec get_target() :: target()
-  if Mix.target() == :host do
-    def get_target() do
-      [architecture, vendor, os | maybe_abi] =
-        :erlang.system_info(:system_architecture) |> List.to_string() |> String.split("-")
+  case System.fetch_env("CROSSCOMPILE") do
+    :error ->
+      def get_target() do
+        [architecture, vendor, os | maybe_abi] =
+          :erlang.system_info(:system_architecture) |> List.to_string() |> String.split("-")
 
-      %{
-        architecture: architecture,
-        vendor: vendor,
-        os: os,
-        abi: List.first(maybe_abi) || :unknown
-      }
-    end
-  else
-    def get_target() do
-      %{
-        architecture: :unknown,
-        vendor: :unknown,
-        os: :unknown,
-        abi: :unknown
-      }
-    end
+        %{
+          architecture: architecture,
+          vendor: vendor,
+          os: os,
+          abi: List.first(maybe_abi) || :unknown
+        }
+      end
+
+    {:ok, _} ->
+      def get_target() do
+        unquote(
+          Enum.map(
+            [
+              {:architecture, "TARGET_ARCH"},
+              {:vendor, "TARGET_VENDOR"},
+              {:os, "TARGET_OS"},
+              {:abi, "TARGET_ABI"}
+            ],
+            fn {key, env} ->
+              value =
+                case System.fetch_env(env) do
+                  {:ok, value} -> value
+                  :error -> :unknown
+                end
+
+              {key, value}
+            end
+          )
+        )
+        |> Enum.into(%{})
+      end
   end
 
   @doc """
   Returns current platform name.
   """
+  @deprecated "Use Bundlex.get_target/0 instead"
   @spec platform() :: platform_t()
   def platform() do
     Platform.get_target!()

lib/bundlex/platform.ex

@@ -41,24 +41,25 @@ defmodule Bundlex.Platform do
   Otherwise raises Mix error.
   """
   @spec get_target!() :: name_t
-  mix_target = Mix.target()
-
-  if mix_target == :host do
-    def get_target!(), do: get_host!()
-  else
-    def get_target!() do
-      case System.fetch_env("NERVES_APP") do
-        {:ok, _app} ->
-          :nerves
-
-        :error ->
-          Output.warn(
-            "Custom MIX_TARGET #{inspect(unquote(mix_target))} is not directly supported. Make sure necessary environment variables are set correctly."
-          )
-
-         :custom
+
+  case System.fetch_env("CROSSCOMPILE") do
+    :error ->
+      def get_target!(), do: get_host!()
+
+    {:ok, _} ->
+      def get_target!() do
+        case System.fetch_env("NERVES_APP") do
+          {:ok, _app} ->
+            :nerves
+
+          :error ->
+            Output.warn(
+              "Cross-compiling without using Nerves. Make sure necessary environment variables are set correctly."
+            )
+
+            :custom
+        end
       end
-    end
   end
 
   @spec get_host!() :: name_t

lib/bundlex/toolchain/common/unix/os_deps.ex

@@ -2,7 +2,7 @@ defmodule Bundlex.Toolchain.Common.Unix.OSDeps do
   @moduledoc false
 
   require Logger
-  alias Bundlex.Output
+  alias Bundlex.{Output, Platform}
 
   @spec resolve_os_deps(Bundlex.Native.t()) :: Bundlex.Native.t()
   def resolve_os_deps(native) do
@@ -147,7 +147,7 @@ defmodule Bundlex.Toolchain.Common.Unix.OSDeps do
 
     # TODO: pass the platform via arguments
     # $ORIGIN must be escaped so that it's not treated as an ENV variable
-    rpath_root = if Bundlex.platform() == :macosx, do: "@loader_path", else: "\\$ORIGIN"
+    rpath_root = if Platform.get_target!() == :macosx, do: "@loader_path", else: "\\$ORIGIN"
 
     [
       "-L#{Path.join(dep_path, "lib")}",

lib/mix/tasks/compile.bundlex.ex

@@ -23,7 +23,7 @@ defmodule Mix.Tasks.Compile.Bundlex do
     commands = []
 
     app = MixHelper.get_app!()
-    platform = Bundlex.platform()
+    platform = Platform.get_target!()
 
     project =
       with {:ok, project} <- Project.get(app) do

mix.exs

@@ -1,7 +1,7 @@
 defmodule Bundlex.Mixfile do
   use Mix.Project
 
-  @version "1.4.6"
+  @version "1.5.0"
   @github_url "https://github.com/membraneframework/bundlex"
 
   def project do