native_deps: give up on testing cc_binary using rust_library

This only works on clang today, and can only work on clang for the
near-term. It's not clear how to write a clang-only test in this case,
so we just give up for now.

"I promise it works!" etc

Author: durin42

test/unit/native_deps/alloc_shims.c

@@ -1,7 +1,7 @@
 """Unittests for rust rules."""
 
 load("@bazel_skylib//lib:unittest.bzl", "analysistest", "asserts", "unittest")
-load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_library")
+load("@rules_cc//cc:defs.bzl", "cc_library")
 load("//rust:defs.bzl", "rust_binary", "rust_library", "rust_proc_macro", "rust_shared_library", "rust_static_library")
 
 def _assert_argv_contains_not(env, action, flag):
@@ -227,25 +227,6 @@ def _native_dep_test():
         deps = [":native_dep", ":alwayslink"],
     )
 
-    cc_library(
-        name = "alloc_shims",
-        srcs = ["alloc_shims.c"],
-    )
-
-    rust_library(
-        name = "print_hi_rust",
-        srcs = ["print_hi_rust.rs"],
-    )
-
-    cc_binary(
-        name = "cc_bin_uses_rust_library",
-        srcs = ["cc_bin_uses_rust_library.cc"],
-        deps = [
-            ":print_hi_rust",
-            ":alloc_shims",  # TODO: this should come in through the toolchain configuration
-        ],
-    )
-
     rlib_has_no_native_libs_test(
         name = "rlib_has_no_native_libs_test",
         target_under_test = ":rlib_has_no_native_dep",

test/unit/native_deps/cc_bin_uses_rust_library.cc

@@ -1,4 +1,5 @@
-load("@bazel_skylib//lib:unittest.bzl", "analysistest", "asserts", "unittest")
+"""Unittest to verify ordering of rust stdlib in rust_library() CcInfo"""
+load("@bazel_skylib//lib:unittest.bzl", "analysistest", "asserts")
 load("//rust:defs.bzl", "rust_library")
 
 def _categorize_library(name):
@@ -13,11 +14,11 @@ def _categorize_library(name):
         return "compiler_builtins"
     return "other"
 
-def _dedup_preserving_order(l):
+def _dedup_preserving_order(list):
     """Given a list, deduplicate its elements preserving order."""
     r = []
     seen = {}
-    for e in l:
+    for e in list:
         if e in seen:
             continue
         seen[e] = 1
@@ -27,9 +28,9 @@ def _dedup_preserving_order(l):
 def _libstd_ordering_test_impl(ctx):
     env = analysistest.begin(ctx)
     tut = analysistest.target_under_test(env)
-    libs = [l.static_library for li in tut[CcInfo].linking_context.linker_inputs.to_list() for l in li.libraries]
-    rlibs = [_categorize_library(l.basename) for l in libs if ".rlib" in l.basename]
-    set_to_check = _dedup_preserving_order([l for l in rlibs if l != "other"])
+    libs = [lib.static_library for li in tut[CcInfo].linking_context.linker_inputs.to_list() for lib in li.libraries]
+    rlibs = [_categorize_library(lib.basename) for lib in libs if ".rlib" in lib.basename]
+    set_to_check = _dedup_preserving_order([lib for lib in rlibs if lib != "other"])
     asserts.equals(env, ["std", "core", "compiler_builtins", "alloc"], set_to_check)
     return analysistest.end(env)