Added logic for (hopefully) properly detecting framework paths

build.rs

@@ -1,10 +1,32 @@
 extern crate bindgen;
 
-#[cfg(any(target_os = "macos", target_os = "ios"))]
-fn main() {
-    use std::env;
-    use std::path::PathBuf;
+fn frameworks_path() -> Result<String, std::io::Error> {
+    // While macOS has its system frameworks located at "/System/Library/Frameworks"
+    // for actually linking against them (especially for cross-compilation) once
+    // has to refer to the frameworks as found within "Xcode.app/Contents/Developer/…".
+
+    use std::process::Command;
+
+    let output = Command::new("xcode-select").arg("-p").output()?.stdout;
+    let prefix_str = std::str::from_utf8(&output).expect("invalid output from `xcode-select`");
+    let prefix = prefix_str.trim_right();
+
+    let platform = if cfg!(target_os = "macos") {
+        "MacOSX"
+    } else if cfg!(target_os = "ios") {
+        "iPhoneOS"
+    } else {
+        unreachable!();
+    };
+
+    let infix = format!("Platforms/{}.platform/Developer/SDKs/{}.sdk", platform, platform);
+    let suffix = "System/Library/Frameworks";
+    let directory = format!("{}/{}/{}", prefix, infix, suffix);
+
+    Ok(directory)
+}
 
+fn build(frameworks_path: &str) {
     // Generate one large set of bindings for all frameworks.
     //
     // We do this rather than generating a module per framework as some frameworks depend on other
@@ -14,43 +36,46 @@ fn main() {
     // Only link to each framework and include their headers if their features are enabled and they
     // are available on the target os.
 
+    use std::env;
+    use std::path::PathBuf;
+
     let mut frameworks = vec![];
     let mut headers = vec![];
 
     #[cfg(feature = "audio_toolbox")]
     {
         println!("cargo:rustc-link-lib=framework=AudioToolbox");
-        frameworks.push("/System/Library/Frameworks/AudioToolbox");
-        headers.push("/System/Library/Frameworks/AudioToolbox.framework/Headers/AudioToolbox.h");
+        frameworks.push("AudioToolbox");
+        headers.push("AudioToolbox.framework/Headers/AudioToolbox.h");
     }
 
     #[cfg(feature = "audio_unit")]
     {
         println!("cargo:rustc-link-lib=framework=AudioUnit");
-        frameworks.push("/System/Library/Frameworks/AudioUnit");
-        headers.push("/System/Library/Frameworks/AudioUnit.framework/Headers/AudioUnit.h");
+        frameworks.push("AudioUnit");
+        headers.push("AudioUnit.framework/Headers/AudioUnit.h");
     }
 
     #[cfg(feature = "core_audio")]
     {
         println!("cargo:rustc-link-lib=framework=CoreAudio");
-        frameworks.push("/System/Library/Frameworks/CoreAudio");
-        headers.push("/System/Library/Frameworks/CoreAudio.framework/Headers/CoreAudio.h");
+        frameworks.push("CoreAudio");
+        headers.push("CoreAudio.framework/Headers/CoreAudio.h");
     }
 
     #[cfg(feature = "open_al")]
     {
         println!("cargo:rustc-link-lib=framework=OpenAL");
-        frameworks.push("/System/Library/Frameworks/OpenAL");
-        headers.push("/System/Library/Frameworks/OpenAL.framework/Headers/al.h");
-        headers.push("/System/Library/Frameworks/OpenAL.framework/Headers/alc.h");
+        frameworks.push("OpenAL");
+        headers.push("OpenAL.framework/Headers/al.h");
+        headers.push("OpenAL.framework/Headers/alc.h");
     }
 
     #[cfg(all(feature = "core_midi", target_os = "macos"))]
     {
         println!("cargo:rustc-link-lib=framework=CoreMIDI");
-        frameworks.push("/System/Library/Frameworks/CoreMIDI");
-        headers.push("/System/Library/Frameworks/CoreMIDI.framework/Headers/CoreMIDI.h");
+        frameworks.push("CoreMIDI");
+        headers.push("CoreMIDI.framework/Headers/CoreMIDI.h");
     }
 
     // Get the cargo out directory.
@@ -59,14 +84,18 @@ fn main() {
     // Begin building the bindgen params.
     let mut builder = bindgen::Builder::default();
 
+    builder = builder.clang_arg(format!("-F/{}", frameworks_path));
+
     // Add all headers.
-    for header_path in headers {
-        builder = builder.header(header_path);
+    for relative_path in headers {
+        let absolute_path = format!("{}/{}", frameworks_path, relative_path);
+        builder = builder.header(absolute_path);
     }
 
     // Link to all frameworks.
-    for framework in frameworks {
-        builder = builder.link_framework(framework);
+    for relative_path in frameworks {
+        let absolute_path = format!("{}/{}", frameworks_path, relative_path);
+        builder = builder.link_framework(absolute_path);
     }
 
     // Generate the bindings.
@@ -80,7 +109,16 @@ fn main() {
     bindings.write_to_file(out_dir.join("coreaudio.rs")).expect("could not write bindings");
 }
 
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+fn main() {
+    if let Ok(directory) = frameworks_path() {
+        build(&directory);
+    } else {
+        eprintln!("coreaudio-sys could not find frameworks path");
+    }
+}
+
 #[cfg(not(any(target_os = "macos", target_os = "ios")))]
 fn main() {
-    eprintln!("coreaudio-sys requires macos or ios");
+    eprintln!("coreaudio-sys requires macos or ios target");
 }