Add cras_rust_library to automatically select bazel or system cras_rust

The new pattern is:
1.  Rust crates use cras_rust_library
2.  If the rust package happens to have C headers, create
    a cc_library to wrap the cras_rust_library and add hdrs
    to it.

This is done so that:
1.  If a cc_library only depends on a small crate, it doesn't have
    to depend the full //cras/src/server/rust.
2.  Allows moving the headers for Rust crates to be alongside
    their sources.

Also move @pkg_config//dbus-1 to a better location.

BUG=b:314126577
TEST=CQ

Change-Id: Id398d12cf4af7b8685f29511327fc060f19849d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/5216247
Reviewed-by: Chih-Yang Hsia <paulhsia@chromium.org>
Tested-by: chromeos-cop-builder@chromeos-cop.iam.gserviceaccount.com <chromeos-cop-builder@chromeos-cop.iam.gserviceaccount.com>
Commit-Queue: Li-Yu Yu <aaronyu@google.com>

cras/server/platform/dlc/BUILD.bazel

@@ -14,6 +14,7 @@ rust_library(
     visibility = ["//cras/src/server/rust:__pkg__"],
     deps = all_crate_deps() + [
         "//cras/server/s2",
+        "@pkg_config//dbus-1",
     ],
     # TODO: Enable "dlc" feature based on //:dlc_build
 )

cras/server/platform/features/BUILD.bazel

@@ -24,7 +24,7 @@ cc_library(
     deps = [
         "//cras/common:check",
         "//cras/server:main_message",
-        "//cras/src/server/rust",
+        "//cras/src/server/rust:cc",
     ],
 )
 

cras/src/common/BUILD.bazel

@@ -139,7 +139,7 @@ cc_library(
         "//cras/src/tests:__pkg__",
     ],
     deps = [
-        "//cras/src/server/rust",
+        "//cras/src/server/rust:cc",
     ],
 )
 

cras/src/server/BUILD.bazel

@@ -262,7 +262,7 @@ cc_library(
         ":ewma_power",
         "//cras/server/platform/features",
         "//cras/src/common",
-        "//cras/src/server/rust",
+        "//cras/src/server/rust:cc",
     ] + select({
         "//:ml_build": ["//cras/src/dsp:am"],
         "//conditions:default": [],
@@ -503,7 +503,7 @@ cc_library(
         "//cras/src/dsp",
         "//cras/src/plc",
         "//cras/src/server/config",
-        "//cras/src/server/rust",
+        "//cras/src/server/rust:cc",
         "@pkg_config//alsa",
         "@pkg_config//dbus-1",
         "@pkg_config//libudev",
@@ -550,7 +550,7 @@ cc_library(
         "//cras/server/platform/features",
         "//cras/src/common",
         "//cras/src/dsp",
-        "//cras/src/server/rust",
+        "//cras/src/server/rust:cc",
     ] + select({
         "//:apm_build": ["@webrtc_apm//webrtc_apm"],
         "//conditions:default": [],

cras/src/server/rust/BUILD.bazel

@@ -5,30 +5,14 @@
 load("@crate_index//:defs.bzl", "all_crate_deps")
 load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 load("@rules_rust//cargo:defs.bzl", "cargo_build_script")
-load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")
+load("@rules_rust//rust:defs.bzl", "rust_test")
 load("//:utils.bzl", "require_no_config")
 load("//rules/cbindgen:rules.bzl", "cras_cbindgen")
+load("//rules/rust:defs.bzl", "cras_rust_library")
 
-cc_library(
+cras_rust_library(
     name = "rust",
-    hdrs = glob(include = ["include/*.h"]),
-    visibility = ["//visibility:public"],
-    deps = select({
-        "//:system_cras_rust_build": [
-            "//cras/src/server/rust/system_cras_rust",
-        ],
-        "//conditions:default": [
-            ":lib",
-        ],
-    }) + [
-        "@pkg_config//dbus-1",
-    ],
-)
-
-rust_library(
-    name = "lib",
     srcs = glob(include = ["src/**/*.rs"]),
-    target_compatible_with = require_no_config("//:system_cras_rust_build"),
     deps = [
         ":build_script",
         "//audio_processor",
@@ -39,6 +23,13 @@ rust_library(
     ] + all_crate_deps(),
 )
 
+cc_library(
+    name = "cc",
+    hdrs = glob(include = ["include/*.h"]),
+    visibility = ["//visibility:public"],
+    deps = [":rust"],
+)
+
 cargo_build_script(
     name = "build_script",
     srcs = ["build.rs"],
@@ -50,7 +41,7 @@ cargo_build_script(
 
 rust_test(
     name = "test",
-    crate = ":lib",
+    crate = ":rust",
     tags = [
         "tsan-broken",
     ],
@@ -61,7 +52,7 @@ cc_test(
     name = "cras_processor_test",
     srcs = ["cras_processor_test.cc"],
     deps = [
-        ":rust",
+        ":cc",
         "//audio_processor/c:plugin_processor",
         "@pkg_config//gtest",
         "@pkg_config//gtest_main",
@@ -72,7 +63,7 @@ cc_test(
     name = "pseudonymization_test",
     srcs = ["pseudonymization_test.cc"],
     deps = [
-        ":rust",
+        ":cc",
         "@pkg_config//gtest",
         "@pkg_config//gtest_main",
     ],
@@ -82,7 +73,7 @@ cc_test(
     name = "pseudonymization_none_test",
     srcs = ["pseudonymization_none_test.cc"],
     deps = [
-        ":rust",
+        ":cc",
         "@pkg_config//gtest",
         "@pkg_config//gtest_main",
     ],
@@ -92,7 +83,7 @@ cc_test(
     name = "cras_fra_test",
     srcs = ["cras_fra_test.cc"],
     deps = [
-        ":rust",
+        ":cc",
         "@pkg_config//gtest",
         "@pkg_config//gtest_main",
     ],

cras/src/server/rust/system_cras_rust/BUILD.bazel

@@ -2,6 +2,9 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+load("@rules_cc//cc:defs.bzl", "cc_import")
+load("@rules_python//python:defs.bzl", "py_binary")
+
 """This package holds the magic to find libcras_rust.a as the way
 the compiler does and list it explicitly in the dependency.
 
@@ -26,6 +29,7 @@ cc_import(
     target_compatible_with = require_config("//:system_cras_rust_build"),
     visibility = ["//cras/src/server/rust:__pkg__"],
     deps = [
+        "@pkg_config//dbus-1",
         "@pkg_config//openssl",
         "@pkg_config//speexdsp",
     ] + select({