bazel: add placeholder as an example

- Make examples and tests work, both with Cargo and Bazel.
- Remove obsolete test examples.
- Add Python dependency.

Author: arkjedrz

Cargo.lock

@@ -1,10 +1,14 @@
 [workspace]
 resolver = "2"
-# Split to default members without component integration tests.
+# Split to default members without tests and examples.
 # Used when executing cargo from project root.
-default-members = []
-# Include component integration tests as a member for IDE support and Bazel builds.
-members = []
+default-members = ["src/mw/_placeholder"]
+# Include tests and examples as a member for IDE support and Bazel builds.
+members = [
+    "src/mw/_placeholder",
+    "examples/mw/_placeholder_example",
+    "tests/mw/_placeholder",
+]
 
 
 [workspace.package]
@@ -15,6 +19,7 @@ authors = ["S-CORE Contributors"]
 
 
 [workspace.dependencies]
+_placeholder = { path = "src/mw/_placeholder" }
 
 
 [workspace.lints.clippy]

Cargo.toml

@@ -17,6 +17,7 @@ module(
 )
 
 # Bazel global rules
+bazel_dep(name = "rules_python", version = "1.7.0")
 bazel_dep(name = "bazel_skylib", version = "1.8.2")
 bazel_dep(name = "rules_rust", version = "0.67.0")
 bazel_dep(name = "rules_cc", version = "0.2.14")
@@ -45,24 +46,12 @@ bazel_dep(name = "custom_qemu", version = "1.0.0", dev_dependency = True)
 bazel_dep(name = "googletest", version = "1.17.0")
 
 # Overrides
-# git_override(
-#     module_name = "score_platform",
-#     commit = "bcab25561cdce7bd4eeebdb20b0ba4e2a4becc12",
-#     remote = "https://github.com/eclipse-score/score.git",
-# )
-
 git_override(
     module_name = "score_toolchains_rust",
     commit = "6651945b4ba8e7c342d9740e9cb2d37842f56261",
     remote = "https://github.com/eclipse-score/toolchains_rust.git",
 )
 
-# git_override(
-#     module_name = "score_toolchains_qnx",
-#     commit = "3477ac13a8015a4e2016588fba573c2f9519237d",
-#     remote = "https://github.com/eclipse-score/toolchains_qnx.git",
-# )
-
 git_override(
     module_name = "score_virtualization",
     commit = "1d9e73212cc291c37a1b7c1427e0f34368ef25e0",
@@ -103,6 +92,15 @@ toolchains_qnx.sdp(
     url = "https://www.qnx.com/download/download/79858/installation.tgz",
 )
 
+PYTHON_VERSION = "3.12"
+
+python = use_extension("@rules_python//python/extensions:python.bzl", "python", dev_dependency = True)
+python.toolchain(
+    is_default = True,
+    python_version = PYTHON_VERSION,
+)
+use_repo(python)
+
 use_repo(toolchains_qnx, "toolchains_qnx_sdp")
 use_repo(toolchains_qnx, "toolchains_qnx_qcc")
 use_repo(toolchains_qnx, "toolchains_qnx_ifs")
@@ -129,7 +127,10 @@ crate.from_cargo(
     name = "score_baselibs_rust_crates",
     cargo_lockfile = "//:Cargo.lock",
     manifests = [
-        # TODO: expand along with `Cargo.toml`.
+        "//:Cargo.toml",
+        "//:src/mw/_placeholder/Cargo.toml",
+        "//:examples/mw/_placeholder_example/Cargo.toml",
+        "//:tests/mw/_placeholder/Cargo.toml",
     ],
 
     # This shall not be here but rules_rust 0.61.0 or even 0.67.0 does not correct finds out that when we use out platform it shall append

MODULE.bazel

@@ -10,10 +10,16 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
-cc_test(
-    name = "cpp_test_main",
-    srcs = ["test_main.cpp"],
-    deps = [
-        "@googletest//:gtest_main",  # GoogleTest dependency via Bazel Modules
+
+load("@rules_rust//rust:defs.bzl", "rust_binary")
+load("@score_baselibs_rust_crates//:defs.bzl", "all_crate_deps")
+
+rust_binary(
+    name = "_placeholder_example",
+    srcs = glob(["src/**/*.rs"]),
+    deps = all_crate_deps(
+        normal = True,
+    ) + [
+        "//src/mw/_placeholder",
     ],
 )

tests/cpp/BUILD examples/mw/_placeholder_example/BUILDtests/cpp/BUILD renamed to examples/mw/_placeholder_example/BUILD

@@ -0,0 +1,12 @@
+[package]
+name = "_placeholder_example"
+version.workspace = true
+edition.workspace = true
+license-file.workspace = true
+authors.workspace = true
+
+[dependencies]
+_placeholder.workspace = true
+
+[lints]
+workspace = true

examples/mw/_placeholder_example/Cargo.toml

@@ -0,0 +1,4 @@
+fn main() {
+    let result = _placeholder::add(4, 8);
+    println!("Result: {result}");
+}

examples/mw/_placeholder_example/src/main.rs

@@ -0,0 +1,30 @@
+# *******************************************************************************
+# Copyright (c) 2025 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")
+load("@score_baselibs_rust_crates//:defs.bzl", "all_crate_deps")
+
+rust_library(
+    name = "_placeholder",
+    srcs = glob(["src/**/*.rs"]),
+    visibility = ["//visibility:public"],
+)
+
+rust_test(
+    name = "_placeholder_tests",
+    crate = ":_placeholder",
+    deps = all_crate_deps(
+        normal = True,
+    ) + [
+        "//src/mw/_placeholder",
+    ],
+)

src/mw/_placeholder/BUILD

@@ -0,0 +1,11 @@
+[package]
+name = "_placeholder"
+version.workspace = true
+edition.workspace = true
+license-file.workspace = true
+authors.workspace = true
+
+[dependencies]
+
+[lints]
+workspace = true

src/mw/_placeholder/Cargo.toml

@@ -0,0 +1,4 @@
+# `_placeholder`
+
+This project is only used to check Cargo/Bazel integration in `baselibs_rust`.
+It is meant to be removed once **any other component** is added to this repo.

src/mw/_placeholder/README.md

@@ -0,0 +1,14 @@
+pub fn add(left: u64, right: u64) -> u64 {
+    left + right
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let result = add(2, 2);
+        assert_eq!(result, 4);
+    }
+}