Add Vendored Libdbus Support

.github/workflows/dbus-rs-github-ci.yml

@@ -10,6 +10,68 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
+  # Taken from rust-lang/libz-sys CI/CD example.
+  #
+  # This job downloads and stores `cross` as an artifact, so that it can be
+  # redownloaded across all of the jobs.
+  install-cross:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: XAMPPRocky/get-github-release@v1
+        id: cross
+        with:
+          owner: rust-embedded
+          repo: cross
+          matches: ${{ matrix.platform }}
+          token: ${{ secrets.GITHUB_TOKEN }}
+      - uses: actions/upload-artifact@v2
+        with:
+          name: cross-${{ matrix.platform }}
+          path: ${{ steps.cross.outputs.install_path }}
+    strategy:
+      matrix:
+        platform: [linux-musl]
+
+  # Cross compile vendored libdbus for multiple architectures.
+  #
+  # Cannot run the full dbus test suite since the cross docker image doesn't
+  # have dbus-daemon running.
+  libdbus-sys-linux:
+    runs-on: ubuntu-latest
+    needs: install-cross
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        submodules: 'recursive'
+    - uses: actions-rs/toolchain@v1
+      with:
+          profile: minimal
+          toolchain: stable
+          override: true
+    - name: Download Cross
+      uses: actions/download-artifact@v1
+      with:
+        name: cross-linux-musl
+        path: /tmp
+    - run: rustup toolchain install ${{ matrix.channel }}
+    - run: chmod +x /tmp/cross
+    - name: Build
+      run: /tmp/cross build --package dbus --features vendored --target ${{ matrix.target }}
+    - name: Run tests
+      run: /tmp/cross test --package libdbus-sys --features vendored --target ${{ matrix.target }}
+    strategy:
+      fail-fast: false
+      matrix:
+        channel: [stable]
+        target:
+          - mips64-unknown-linux-muslabi64
+          - mips-unknown-linux-musl
+          - aarch64-unknown-linux-musl
+          - arm-unknown-linux-musleabihf
+          - i686-unknown-linux-musl
+          - x86_64-unknown-linux-musl
+          - x86_64-unknown-linux-gnu
+
   build:
 
     runs-on: ubuntu-latest

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "libdbus-sys/vendor/dbus"]
+	path = libdbus-sys/vendor/dbus
+	url = https://github.com/freedesktop/dbus.git

dbus/Cargo.toml

@@ -30,6 +30,7 @@ tempfile = "3"
 
 [features]
 no-string-validation = []
+vendored = ["libdbus-sys/vendored"]
 futures = ["futures-util", "futures-channel"]
 # Not ready yet
 # native-channel = ["futures-executor", "futures-util/io", "dbus-native-channel"]

libdbus-sys/Cargo.toml

@@ -13,8 +13,15 @@ categories = ["os::unix-apis", "external-ffi-bindings"]
 build = "build.rs"
 links = "dbus"
 
+[features]
+# By default use pkg-config to locate the local libdbus installation
+default = ["pkg-config"]
+# Provide vendoring as an option, which will compile libdbus from source for the target
+vendored = ["cc"]
+
 [build-dependencies]
-pkg-config = "0.3"
+pkg-config = {version = "0.3", optional = true}
+cc = {version = "1.0.78", optional = true }
 
 [package.metadata.pkg-config]
 dbus-1 = "1.6"

libdbus-sys/build.rs

@@ -1,8 +1,17 @@
 extern crate pkg_config;
+use std::error::Error;
+
+#[cfg(feature = "vendored")]
+mod build_vendored;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    // Invalidate the built crate whenever these files change
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=build_vendored.rs");
 
-fn main() {
     // See https://github.com/joshtriplett/metadeps/issues/9 for why we don't use
     // metadeps here, but instead keep this manually in sync with Cargo.toml.
+    #[cfg(not(feature = "vendored"))]
     if let Err(e) = pkg_config::Config::new().atleast_version("1.6").probe("dbus-1") {
         eprintln!("pkg_config failed: {}", e);
         eprintln!(
@@ -15,4 +24,8 @@ fn main() {
         );
         panic!();
     }
+
+    #[cfg(feature = "vendored")]
+    build_vendored::build_libdbus()?;
+    Ok(())
 }