Provide BAZEL_CURRENT_REPOSITORY local define in cc_* rules

`BAZEL_CURRENT_REPOSITORY` contains the canonical name of the repository
containing the current target and is required to look up runfiles using
apparent repository names when repository mappings are used, e.g. with
Bzlmod.

Work towards #16124

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

@@ -690,7 +690,7 @@ def cc_binary_impl(ctx, additional_linkopts):
         cc_toolchain = cc_toolchain,
         user_compile_flags = cc_helper.get_copts(ctx, common, feature_configuration, additional_make_variable_substitutions),
         defines = common.defines,
-        local_defines = common.local_defines,
+        local_defines = common.local_defines + cc_helper.get_local_defines_for_runfiles_lookup(ctx),
         loose_includes = common.loose_include_dirs,
         system_includes = common.system_include_dirs,
         private_hdrs = common.private_hdrs,

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

@@ -916,6 +916,9 @@ def _is_stamping_enabled_for_aspect(ctx):
         stamp = ctx.rule.attr.stamp
     return stamp
 
+def _get_local_defines_for_runfiles_lookup(ctx):
+    return ["BAZEL_CURRENT_REPOSITORY=\"{}\"".format(ctx.label.workspace_name)]
+
 cc_helper = struct(
     merge_cc_debug_contexts = _merge_cc_debug_contexts,
     is_code_coverage_enabled = _is_code_coverage_enabled,
@@ -960,4 +963,5 @@ cc_helper = struct(
     build_linking_context_from_libraries = _build_linking_context_from_libraries,
     is_stamping_enabled = _is_stamping_enabled,
     is_stamping_enabled_for_aspect = _is_stamping_enabled_for_aspect,
+    get_local_defines_for_runfiles_lookup = _get_local_defines_for_runfiles_lookup,
 )

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

@@ -58,7 +58,7 @@ def _cc_library_impl(ctx):
         feature_configuration = feature_configuration,
         user_compile_flags = cc_helper.get_copts(ctx, common, feature_configuration, additional_make_variable_substitutions),
         defines = common.defines,
-        local_defines = common.local_defines,
+        local_defines = common.local_defines + cc_helper.get_local_defines_for_runfiles_lookup(ctx),
         loose_includes = common.loose_include_dirs,
         system_includes = common.system_include_dirs,
         copts_filter = common.copts_filter,

src/test/shell/bazel/cc_integration_test.sh

@@ -1594,4 +1594,118 @@ function test_external_cc_test_local_sibling_repository_layout() {
       @other_repo//test >& $TEST_log || fail "Test should pass"
 }
 
+function test_bazel_current_repository_define() {
+  cat >> WORKSPACE <<'EOF'
+local_repository(
+  name = "other_repo",
+  path = "other_repo",
+)
+EOF
+
+  mkdir -p pkg
+  cat > pkg/BUILD.bazel <<'EOF'
+cc_library(
+  name = "library",
+  srcs = ["library.cpp"],
+  hdrs = ["library.h"],
+  visibility = ["//visibility:public"],
+)
+
+cc_binary(
+  name = "binary",
+  srcs = ["binary.cpp"],
+  deps = [":library"],
+)
+
+cc_test(
+  name = "test",
+  srcs = ["test.cpp"],
+  deps = [":library"],
+)
+EOF
+
+  cat > pkg/library.cpp <<'EOF'
+#include "library.h"
+#include <iostream>
+void print_repo_name() {
+  std::cout << "in " << __FILE__ << ": '" << BAZEL_CURRENT_REPOSITORY << "'" << std::endl;
+}
+EOF
+
+  cat > pkg/library.h <<'EOF'
+void print_repo_name();
+EOF
+
+  cat > pkg/binary.cpp <<'EOF'
+#include <iostream>
+#include "library.h"
+int main() {
+  std::cout << "in " << __FILE__ << ": '" << BAZEL_CURRENT_REPOSITORY << "'" << std::endl;
+  print_repo_name();
+}
+EOF
+
+  cat > pkg/test.cpp <<'EOF'
+#include <iostream>
+#include "library.h"
+int main() {
+  std::cout << "in " << __FILE__ << ": '" << BAZEL_CURRENT_REPOSITORY << "'" << std::endl;
+  print_repo_name();
+}
+EOF
+
+  mkdir -p other_repo
+  touch other_repo/WORKSPACE
+
+  mkdir -p other_repo/pkg
+  cat > other_repo/pkg/BUILD.bazel <<'EOF'
+cc_binary(
+  name = "binary",
+  srcs = ["binary.cpp"],
+  deps = ["@//pkg:library"],
+)
+
+cc_test(
+  name = "test",
+  srcs = ["test.cpp"],
+  deps = ["@//pkg:library"],
+)
+EOF
+
+  cat > other_repo/pkg/binary.cpp <<'EOF'
+#include <iostream>
+#include "pkg/library.h"
+int main() {
+  std::cout << "in " << __FILE__ << ": '" << BAZEL_CURRENT_REPOSITORY << "'" << std::endl;
+  print_repo_name();
+}
+EOF
+
+  cat > other_repo/pkg/test.cpp <<'EOF'
+#include <iostream>
+#include "pkg/library.h"
+int main() {
+  std::cout << "in " << __FILE__ << ": '" << BAZEL_CURRENT_REPOSITORY << "'" << std::endl;
+  print_repo_name();
+}
+EOF
+
+  bazel run //pkg:binary &>"$TEST_log" || fail "Run should succeed"