Express the multi-arch nature of .beam files via a transition

This allows beam files to cache across architectures

Author: HoloRin

erlang_app_info.bzl

@@ -1,3 +1,5 @@
+load("//private:beam_transition.bzl", "beam_transition")
+
 ErlangAppInfo = provider(
     doc = "Compiled Erlang Application",
     fields = {
@@ -62,10 +64,16 @@ erlang_app_info = rule(
         "extra_apps": attr.string_list(),
         "hdrs": attr.label_list(allow_files = True),
         "app": attr.label(allow_files = [".app"]),
-        "beam": attr.label_list(allow_files = [".beam", ".appup"]),
+        "beam": attr.label_list(
+            allow_files = [".beam", ".appup"],
+            cfg = beam_transition,
+        ),
         "priv": attr.label_list(allow_files = True),
         "license_files": attr.label_list(allow_files = True),
         "srcs": attr.label_list(allow_files = True),
         "deps": attr.label_list(providers = [ErlangAppInfo]),
+        "_allowlist_function_transition": attr.label(
+            default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+        ),
     },
 )

private/beam_transition.bzl

@@ -0,0 +1,17 @@
+def _impl(settings, attr):
+    _ignore = (settings, attr)
+
+    # print("_impl")
+    # print("settings", settings)
+    # print("attr", attr)
+    return {
+        "arm": {"//command_line_option:cpu": "arm"},
+        "x86": {"//command_line_option:cpu": "x86"},
+        "k8": {"//command_line_option:cpu": "k8"},
+    }
+
+beam_transition = transition(
+    implementation = _impl,
+    inputs = [],
+    outputs = ["//command_line_option:cpu"],
+)

private/erlang_bytecode2.bzl

@@ -1,5 +1,6 @@
 load("//:erlang_app_info.bzl", "ErlangAppInfo", "flat_deps")
 load("//:util.bzl", "path_join")
+load(":beam_transition.bzl", "beam_transition")
 load(":erlang_bytecode.bzl", "unique_dirnames")
 load(":util.bzl", "erl_libs_contents")
 load(
@@ -133,6 +134,7 @@ erlang_bytecode = rule(
         ),
         "beam": attr.label_list(
             allow_files = [".beam"],
+            cfg = beam_transition,
         ),
         "deps": attr.label_list(
             providers = [ErlangAppInfo],
@@ -146,6 +148,9 @@ erlang_bytecode = rule(
         "outs": attr.output_list(
             mandatory = True,
         ),
+        "_allowlist_function_transition": attr.label(
+            default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+        ),
     },
     toolchains = ["//tools:toolchain_type"],
 )

private/escript_archive.bzl

@@ -12,6 +12,10 @@ load(
     "//:util.bzl",
     "path_join",
 )
+load(
+    ":beam_transition.bzl",
+    "beam_transition",
+)
 load(
     ":util.bzl",
     "additional_file_dest_relative_path",
@@ -117,8 +121,14 @@ escript_archive = rule(
             default = DEFAULT_HEADERS,
         ),
         "srcs": attr.label_list(allow_files = [".erl"]),
-        "beam": attr.label_list(allow_files = [".beam"]),
+        "beam": attr.label_list(
+            allow_files = [".beam"],
+            cfg = beam_transition,
+        ),
         "app": attr.label(providers = [ErlangAppInfo]),
+        "_allowlist_function_transition": attr.label(
+            default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+        ),
     },
     toolchains = ["//tools:toolchain_type"],
     executable = True,

private/escript_flat.bzl

@@ -3,6 +3,10 @@ load(
     "erlang_dirs",
     "maybe_install_erlang",
 )
+load(
+    ":beam_transition.bzl",
+    "beam_transition",
+)
 
 def _impl(ctx):
     out = ctx.actions.declare_file(ctx.attr.out if ctx.attr.out != "" else ctx.label.name)
@@ -63,8 +67,12 @@ escript_flat = rule(
         ),
         "beam": attr.label(
             allow_single_file = [".beam"],
+            cfg = beam_transition,
         ),
         "out": attr.string(),
+        "_allowlist_function_transition": attr.label(
+            default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+        ),
     },
     toolchains = ["//tools:toolchain_type"],
 )

private/eunit.bzl

@@ -4,6 +4,7 @@ load(
     "path_join",
     "windows_path",
 )
+load(":beam_transition.bzl", "beam_transition")
 load(":util.bzl", "erl_libs_contents")
 load(
     "//tools:erlang_toolchain.bzl",
@@ -179,6 +180,7 @@ eunit_test = rule(
         "is_windows": attr.bool(mandatory = True),
         "compiled_suites": attr.label_list(
             allow_files = [".beam"],
+            cfg = beam_transition,
         ),
         "eunit_mods": attr.string_list(),
         "target": attr.label(providers = [ErlangAppInfo]),
@@ -191,6 +193,9 @@ eunit_test = rule(
         ),
         "tools": attr.label_list(),
         "test_env": attr.string_dict(),
+        "_allowlist_function_transition": attr.label(
+            default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+        ),
     },
     toolchains = ["//tools:toolchain_type"],
     test = True,