Add feature flag and instructions to use Mac SDL2 framework

Cargo.toml

@@ -35,3 +35,4 @@ version = "0.8.1"
 
 default = []
 use-pkgconfig = [ "sdl2-sys/use-pkgconfig" ]
+use_mac_framework = ["sdl2-sys/use_mac_framework"]

README.md

@@ -70,6 +70,35 @@ Then add the following to your `~/.bash_profile` if not already present.
 
 If you're having issues with either homebrew or macports, [see here][pdev-issue].
 
+#### If you are using the SDL2 framework
+
+You can download and install the SDL2 Mac OS X framework from:
+https://www.libsdl.org/download-2.0.php
+
+To make the `sdl2` crate link with the SDL2 framework, you will need to enable
+the `use_mac_framework` feature.  To build and test the `sdl2` crate with this
+feature, use:
+
+> cargo test --features use_mac_framework
+
+To depend on the `sdl2` crate with this feature enabled, put the following in
+your project's `Cargo.toml` file:
+
+```toml
+[dependencies.sdl2]
+features = ["use_mac_framework"]
+version = ...  # Whichever version you are using
+```
+
+Alternatively, you can re-export the feature in your package by putting the
+following in your `Cargo.toml` file:
+
+```toml
+[features]
+default = []
+use_sdl2_mac_framework = ["sdl2/use_mac_framework"]
+```
+
 ### Windows (MinGW)
 On Windows, make certain you are using the MinGW version of SDL; the native
 version will crash on `sdl2::init`.

sdl2-sys/Cargo.toml

@@ -25,3 +25,4 @@ optional = true
 default = []
 use-pkgconfig = ["pkg-config"]
 no_std = []
+use_mac_framework = []

sdl2-sys/build.rs

@@ -3,7 +3,11 @@ extern crate pkg_config;
 
 fn main() {
     if !build_pkgconfig() {
-      println!("cargo:rustc-flags=-l SDL2");
+        if cfg!(feature="use_mac_framework") {
+            println!("cargo:rustc-flags=-l framework=SDL2");
+        } else {
+            println!("cargo:rustc-flags=-l SDL2");
+        }
     }
 }
 

sdl2-sys/src/sdl.rs

@@ -3,11 +3,11 @@ use libc::{c_int, c_uint, c_char, uint32_t};
 // Setup linking for all targets.
 #[cfg(target_os="macos")]
 mod mac {
-    #[cfg(mac_framework)]
+    #[cfg(any(mac_framework, feature="use_mac_framework"))]
     #[link(kind="framework", name="SDL2")]
     extern {}
 
-    #[cfg(not(mac_framework))]
+    #[cfg(not(any(mac_framework, feature="use_mac_framework")))]
     #[link(name="SDL2")]
     extern {}
 }