Fix "Make" variable expansion for test rules under Bazel 9 (#3297)

Fixes #3296

---------

Signed-off-by: Aaron Sky <aaronsky@skyaaron.com>

Author: aaronsky

examples/integration/BUILD

@@ -25,6 +25,13 @@ string_flag(
     visibility = ["//visibility:public"],
 )
 
+string_flag(
+    name = "flag_with_make_variable",
+    build_setting_default = "",
+    make_variable = "FLAG_WITH_MAKE_VARIABLE",
+    visibility = ["//visibility:public"],
+)
+
 # Example of xcodeproj cache warming
 #
 # 1. Register a single macOS execution platform in `MODULE.bazel`:

examples/integration/iOSApp/Test/ObjCUnitTests/BUILD

@@ -14,10 +14,12 @@ ios_unit_test(
     bundle_id = "rules-xcodeproj.example.objctests",
     env = {
         "IOS_APP_UNIT_TESTS": "CUSTOM_ENV_VALUE",
+        "IOS_APP_UNIT_TESTS_MAKE": "$(FLAG_WITH_MAKE_VARIABLE)",
     },
     minimum_os_version = "15.0",
     tags = ["manual"],
     test_host = "//iOSApp",
+    toolchains = ["//:flag_with_make_variable"],
     visibility = [
         "//iOSApp:__subpackages__",
         "@rules_xcodeproj//xcodeproj:generated",

xcodeproj/internal/xcodeproj_aspect.bzl

@@ -116,6 +116,9 @@ def _xcodeproj_aspect_impl(target, ctx):
         # one
         rule_attr = ctx.rule.attr
 
+        # Update when Bazel 8 is dropped
+        var_attr = getattr(ctx.rule, "var", ctx.var)
+
         attrs = dir(rule_attr)
         info = xcodeprojinfos.make(
             ctx = ctx,
@@ -127,6 +130,7 @@ def _xcodeproj_aspect_impl(target, ctx):
                 attrs = attrs,
                 rule_attr = rule_attr,
             ),
+            var_attr = var_attr,
         )
         if info:
             providers.append(info)

xcodeproj/internal/xcodeprojinfos.bzl

@@ -260,7 +260,8 @@ def _make_skipped_target_xcodeprojinfo(
         rule_attr,
         skip_type,
         test_env,
-        transitive_infos):
+        transitive_infos,
+        var_attr):
     """Passes through existing target info fields, not collecting new ones.
 
     Merges `XcodeProjInfo`s for the dependencies of the current target, and
@@ -275,6 +276,7 @@ def _make_skipped_target_xcodeprojinfo(
         test_env: `ctx.configuration.test_env`.
         transitive_infos: A `list` of `depset`s of `XcodeProjInfo`s from the
             transitive dependencies of the target.
+        var_attr: `ctx.rule.var` (or `ctx.var` for Bazel 8 and below).
 
     Returns:
         The return value of `_target_info_fields`, with values merged from
@@ -367,7 +369,7 @@ def _make_skipped_target_xcodeprojinfo(
 
             info_env = getattr(rule_attr, automatic_target_info.env, {})
             info_env = {
-                k: ctx.expand_make_variables("env", v, {})
+                k: ctx.expand_make_variables("env", v, var_attr)
                 for k, v in info_env.items()
             }
             env = dicts.add(info_env, test_env)
@@ -756,7 +758,8 @@ def _make_xcodeprojinfo(
         rule_attr,
         rule_kind,
         target,
-        transitive_infos):
+        transitive_infos,
+        var_attr):
     """Creates an `XcodeProjInfo` for the given target.
 
     Args:
@@ -767,6 +770,7 @@ def _make_xcodeprojinfo(
         target: The `Target` to process.
         transitive_infos: A `list` of `XcodeProjInfo`s from the transitive
             dependencies of `target`.
+        var_attr: `ctx.rule.var` (or `ctx.var` for Bazel 8 and below).
 
     Returns:
         An `XcodeProjInfo` populated with information from `target` and
@@ -799,6 +803,7 @@ def _make_xcodeprojinfo(
             skip_type = target_skip_type,
             test_env = ctx.configuration.test_env,
             transitive_infos = transitive_infos,
+            var_attr = var_attr,
         )
     else:
         info_fields = _make_non_skipped_target_xcodeprojinfo(