Add build.rs config to use rust backends.

Cargo.toml

@@ -6,3 +6,7 @@ members = [
     "cubeb-sys",
     "systest"
 ]
+exclude = [
+  "cubeb-sys/libcubeb/src/cubeb-coreaudio-rs",
+  "cubeb-sys/libcubeb/src/cubeb-pulse-rs",
+]

cubeb-sys/Cargo.toml

@@ -15,7 +15,13 @@ circle-ci = { repository = "mozilla/cubeb-rs" }
 
 [features]
 gecko-in-tree = []
+unittest-build = []
 
 [build-dependencies]
 pkg-config = "0.3"
 cmake = "0.1.2"
+
+# Workaround, see build.rs and
+# https://github.com/rust-lang/cargo/issues/4789#issuecomment-2308131243
+[dev-dependencies]
+cubeb-sys = { path = ".", features = ["unittest-build"] }

cubeb-sys/build.rs

@@ -61,15 +61,24 @@ fn main() {
     t!(fs::create_dir_all(env::var("OUT_DIR").unwrap()));
 
     env::remove_var("DESTDIR");
+
+    // Do not build the rust backends for tests: doing so causes duplicate
+    // symbol definitions.
+    #[cfg(feature = "unittest-build")]
+    let build_rust_libs = "OFF";
+    #[cfg(not(feature = "unittest-build"))]
+    let build_rust_libs = "ON";
     let dst = cfg
         .define("BUILD_SHARED_LIBS", "OFF")
         .define("BUILD_TESTS", "OFF")
         .define("BUILD_TOOLS", "OFF")
+        .define("BUILD_RUST_LIBS", build_rust_libs)
         .build();
 
+    let debug = env::var("DEBUG").unwrap().parse::<bool>().unwrap();
+
     println!("cargo:rustc-link-lib=static=cubeb");
     if windows {
-        let debug = env::var("DEBUG").unwrap().parse::<bool>().unwrap();
         println!("cargo:rustc-link-lib=dylib=avrt");
         println!("cargo:rustc-link-lib=dylib=ksuser");
         println!("cargo:rustc-link-lib=dylib=ole32");
@@ -84,6 +93,22 @@ fn main() {
         println!("cargo:rustc-link-lib=framework=CoreAudio");
         println!("cargo:rustc-link-lib=framework=CoreServices");
         println!("cargo:rustc-link-lib=dylib=c++");
+
+        // Do not link the rust backends for tests: doing so causes duplicate
+        // symbol definitions.
+        #[cfg(not(feature = "unittest-build"))]
+        {
+            println!("cargo:rustc-link-lib=static=cubeb_coreaudio");
+            let mut search_path = std::env::current_dir().unwrap();
+            search_path.push("libcubeb/src/cubeb-coreaudio-rs/target");
+            if debug {
+                search_path.push("debug");
+            } else {
+                search_path.push("release");
+            }
+            println!("cargo:rustc-link-search=native={}", search_path.display());
+        }
+
         println!("cargo:rustc-link-search=native={}/lib", dst.display());
     } else {
         if freebsd || android {
@@ -97,7 +122,22 @@ fn main() {
         // Ignore the result of find_library. We don't care if the
         // libraries are missing.
         let _ = pkg_config::find_library("alsa");
-        let _ = pkg_config::find_library("libpulse");
+        if pkg_config::find_library("libpulse").is_ok() {
+            // Do not link the rust backends for tests: doing so causes duplicate
+            // symbol definitions.
+            #[cfg(not(feature = "unittest-build"))]
+            {
+                println!("cargo:rustc-link-lib=static=cubeb_pulse");
+                let mut search_path = std::env::current_dir().unwrap();
+                search_path.push("libcubeb/src/cubeb-pulse/target");
+                if debug {
+                    search_path.push("debug");
+                } else {
+                    search_path.push("release");
+                }
+                println!("cargo:rustc-link-search=native={}", search_path.display());
+            }
+        }
         let _ = pkg_config::find_library("jack");
         let _ = pkg_config::find_library("speexdsp");
         if android {