Optional 10.8 support

README.md

@@ -1,3 +1,9 @@
 # core-foundation-rs
 
 [![Build Status](https://travis-ci.org/servo/core-foundation-rs.svg?branch=master)](https://travis-ci.org/servo/core-foundation-rs)
+
+## Compatibility
+
+By default it targets macOS 10.7.
+
+To enable features added in macOS 10.8, set Cargo feature `mac_os_10_8_features`. To have both 10.8 features and 10.7 compatibility, also set `mac_os_10_7_support`. Setting both requires weak linkage, which is is a nighty-only feature as of Rust 1.19.

core-foundation-sys/Cargo.toml

@@ -10,3 +10,7 @@ build = "build.rs"
 
 [dependencies]
 libc = "0.2"
+
+[features]
+mac_os_10_7_support = [] # backwards compatibility
+mac_os_10_8_features = [] # enables new features

core-foundation-sys/src/lib.rs

@@ -8,6 +8,8 @@
 // except according to those terms.
 #![allow(non_snake_case, non_camel_case_types, non_upper_case_globals, improper_ctypes)]
 
+#![cfg_attr(all(feature="mac_os_10_7_support", feature="mac_os_10_8_features"), feature(linkage))] // back-compat requires weak linkage
+
 extern crate libc;
 
 pub mod array;

core-foundation-sys/src/url.rs

@@ -72,10 +72,13 @@ extern {
     pub static kCFURLParentDirectoryURLKey: CFStringRef;
     pub static kCFURLPreferredIOBlockSizeKey: CFStringRef;
     pub static kCFURLTypeIdentifierKey: CFStringRef;
-    // static kCFURLVolumeIdentifierKey: CFStringRef;
-    // static kCFURLVolumeURLKey: CFStringRef;
-    // static kCFURLIsExcludedFromBackupKey: CFStringRef;
-    // static kCFURLFileResourceTypeKey: CFStringRef;
+    pub static kCFURLVolumeIdentifierKey: CFStringRef;
+    pub static kCFURLVolumeURLKey: CFStringRef;
+
+    #[cfg(feature="mac_os_10_8_features")]
+    #[cfg_attr(feature = "mac_os_10_7_support", linkage = "extern_weak")]
+    pub static kCFURLIsExcludedFromBackupKey: CFStringRef;
+    pub static kCFURLFileResourceTypeKey: CFStringRef;
 
     /* Creating a CFURL */
     pub fn CFURLCopyAbsoluteURL(anURL: CFURLRef) -> CFURLRef;
@@ -151,3 +154,9 @@ extern {
     //fn CFURLStartAccessingSecurityScopedResource
     //fn CFURLStopAccessingSecurityScopedResource
 }
+
+#[test]
+#[cfg(feature="mac_os_10_8_features")]
+fn can_see_excluded_from_backup_key() {
+    let _ = unsafe { kCFURLIsExcludedFromBackupKey };
+}

core-foundation/Cargo.toml

@@ -13,3 +13,7 @@ version = "0.4.2"
 
 [dependencies]
 libc = "0.2"
+
+[features]
+mac_os_10_7_support = ["core-foundation-sys/mac_os_10_7_support"] # backwards compatibility
+mac_os_10_8_features = ["core-foundation-sys/mac_os_10_8_features"] # enables new features