Fix current toolchains (#978)

examples/current_toolchains/BUILD.bazel

@@ -0,0 +1,13 @@
+load("@bazel_skylib//rules:build_test.bzl", "build_test")
+
+genrule(
+    name = "current_make_toolchain_test",
+    outs = ["out.txt"],
+    cmd = "$(MAKE) --version > $@",
+    toolchains = ["@rules_foreign_cc//toolchains:current_make_toolchain"],
+)
+
+build_test(
+    name = "current_toolchain_tests",
+    targets = [":current_make_toolchain_test"],
+)

toolchains/native_tools/native_tools_toolchain.bzl

@@ -1,8 +1,5 @@
 """Rules for building native build tools such as ninja, make or cmake"""
 
-# buildifier: disable=bzl-visibility
-load("//foreign_cc/private:framework.bzl", "expand_locations_and_make_variables")
-
 # buildifier: disable=module-docstring
 ToolInfo = provider(
     doc = "Information about the native tool",
@@ -28,10 +25,10 @@ def _native_tool_toolchain_impl(ctx):
     path = None
     if ctx.attr.target:
         path = ctx.expand_location(ctx.attr.path, targets = [ctx.attr.target])
-        env = expand_locations_and_make_variables(ctx, ctx.attr.env, "env", [ctx.attr.target])
+        env = {k: ctx.expand_location(v, targets = [ctx.attr.target]) for (k, v) in ctx.attr.env.items()}
     else:
         path = ctx.expand_location(ctx.attr.path)
-        env = expand_locations_and_make_variables(ctx, ctx.attr.env, "env", [])
+        env = {k: ctx.expand_location(v) for (k, v) in ctx.attr.env.items()}
     return platform_common.ToolchainInfo(data = ToolInfo(
         env = env,
         path = path,

toolchains/toolchains.bzl

@@ -26,6 +26,7 @@ def _current_toolchain_impl(ctx):
             toolchain,
             platform_common.TemplateVariableInfo(toolchain.data.env),
             DefaultInfo(
+                files = toolchain.data.target.files,
                 runfiles = toolchain.data.target.default_runfiles,
             ),
         ]