Propagate CcInfo for native dependencies

This will, in a follow-up, allow us to create and link `java_{binary,test}#laucher`
as the docs suggest.

Unfortunately, `JavaInfo#transitive_native_libraries` fails to propagate
sufficient information about transitive dependencies of the native
libraries, so linking fails because of missing symbols from transitive
libraries that should be there.

Author: Yannic

java/common/rules/impl/basic_java_library_impl.bzl

@@ -16,6 +16,7 @@
 Common code for reuse across java_* rules
 """
 
+load("@rules_cc//cc/common:cc_common.bzl", "cc_common")
 load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
 load("//java/common/rules:android_lint.bzl", "android_lint_subrule")
 load("//java/private:boot_class_path_info.bzl", "BootClassPathInfo")
@@ -124,6 +125,7 @@ def basic_java_library(
         resources = list(resources)
         resources.extend(properties)
 
+    native_libraries = _collect_native_libraries(deps, runtime_deps, exports)
     java_info, compilation_info = compile_action(
         ctx,
         ctx.outputs.classjar,
@@ -138,7 +140,7 @@ def basic_java_library(
         resources,
         resource_jars,
         classpath_resources,
-        _collect_native_libraries(deps, runtime_deps, exports),
+        native_libraries,
         javacopts,
         neverlink,
         ctx.fragments.java.strict_java_deps,
@@ -150,6 +152,19 @@ def basic_java_library(
     )
     target = {"JavaInfo": java_info}
 
+    if native_libraries:
+        dependencies_cc_info = cc_common.merge_cc_infos(cc_infos = native_libraries)
+
+        # Native dependencies have the same semantics as
+        # `cc_library#implementation_deps`. We only want to propagate
+        # `Cc{Debug,Linking}Context` to libraries depending on this.
+        target["CcInfo"] = CcInfo(
+            linking_context = dependencies_cc_info.linking_context,
+            debug_context = dependencies_cc_info.debug_context(),
+        )
+    else:
+        target["CcInfo"] = CcInfo()
+
     output_groups = dict(
         compilation_outputs = compilation_info.files_to_build,
         _source_jars = java_info.transitive_source_jars,

test/repo/BUILD.bazel

@@ -1,9 +1,30 @@
+load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 load("@rules_java//java:defs.bzl", "java_binary", "java_library", "java_test")  # copybara-use-repo-external-label
 load("@rules_java//toolchains:default_java_toolchain.bzl", "default_java_toolchain")  # copybara-use-repo-external-label
 
+cc_library(
+    name = "native_dep",
+    srcs = [
+        "src/native_dep.cc",
+    ],
+)
+
 java_library(
     name = "lib",
     srcs = ["src/Main.java"],
+    deps = [
+        ":native_dep",
+    ],
+)
+
+cc_test(
+    name = "native_test",
+    srcs = [
+        "src/native_test.cc",
+    ],
+    deps = [
+        ":lib",
+    ],
 )
 
 java_binary(

test/repo/MODULE.bazel

@@ -1,5 +1,6 @@
 module(name = "integration_test_repo")
 
+bazel_dep(name = "rules_cc", version = "0.0.15")
 bazel_dep(name = "rules_java", version = "7.5.0")
 archive_override(
     module_name = "rules_java",

test/repo/src/native_dep.cc

@@ -0,0 +1,3 @@
+int my_number() {
+    return 42;
+}

test/repo/src/native_test.cc

@@ -0,0 +1,12 @@
+#include <iostream>
+
+int my_number();
+
+int main() {
+  int actual = my_number();
+  if (actual != 42) {
+    std::cerr << "Expected my_number() to return 42, got " << actual << std::endl;
+    return 1;
+  }
+  return 0;
+}