Fix make substitution in starlark cc_test env

src/main/starlark/builtins_bzl/common/cc/cc_helper.bzl

@@ -706,13 +706,14 @@ def _get_cc_flags_make_variable(ctx, common, cc_toolchain):
     cc_flags.extend(feature_config_cc_flags)
     return {"CC_FLAGS": " ".join(cc_flags)}
 
-def _expand_nested_variable(ctx, additional_vars, exp, execpath = True, targets = []):
+def _expand_nested_variable(ctx, additional_vars, exp, execpath = True, targets = None):
     # If make variable is predefined path variable(like $(location ...))
     # we will expand it first.
     if exp.find(" ") != -1:
         if not execpath:
             if exp.startswith("location"):
                 exp = exp.replace("location", "rootpath", 1)
+        targets = targets or []
         if ctx.attr.data != None:
             targets.extend(ctx.attr.data)
         return ctx.expand_location("$({})".format(exp), targets = targets)
@@ -738,7 +739,7 @@ def _expand_nested_variable(ctx, additional_vars, exp, execpath = True, targets
         fail("potentially unbounded recursion during expansion of {}".format(exp))
     return exp
 
-def _expand(ctx, expression, additional_make_variable_substitutions, execpath = True, targets = []):
+def _expand(ctx, expression, additional_make_variable_substitutions, execpath = True, targets = None):
     idx = 0
     last_make_var_end = 0
     result = []

src/main/starlark/tests/builtins_bzl/cc/cc_shared_library/test_cc_shared_library/BUILD.builtin_test

@@ -34,7 +34,12 @@ py_test(
 cc_test(
     name = "cc_test",
     srcs = ["main.cc"],
+    data = ["datafile.txt"],
     dynamic_deps = ["foo_so"],
+    env = {
+        "ENV_GENDIR": "$(GENDIR)",
+        "ENV_LOCATION": "$(location :datafile.txt)",
+    },
     features = ["-dynamic_link_test_srcs"],
     deps = ["foo"],
 )

src/main/starlark/tests/builtins_bzl/cc/cc_shared_library/test_cc_shared_library/datafile.txt

@@ -0,0 +1 @@
+hello