Auto merge of #3 - servo:silent-noop, r=jdm

Make the 'egl' cargo feature do nothing instead a build error on non-Windows

Author: bors-servo

.travis.yml

@@ -17,6 +17,7 @@ before_install:
 
 script:
   - cargo test --verbose
+  - cargo test --verbose --features egl  # Doesn’t do anything, but should still build
 
 notifications:
   webhooks: http://build.servo.org:54856/travis

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mozangle"
-version = "0.1.3"
+version = "0.1.4"
 authors = ["The ANGLE Project Authors", "The Servo Project Developers"]
 license = " BSD-3-Clause"
 description = "Mozilla’s fork of Google ANGLE, repackaged as a Rust crate "
@@ -15,4 +15,4 @@ cc = { version = "1.0.5", features = ["parallel"] }
 gl_generator = { version = "0.9.0", optional = true }
 
 [features]
-egl = ["gl_generator"]  # Only supported on Windows
+egl = ["gl_generator"]  # Only does anything on Windows

README.md

@@ -30,18 +30,13 @@ Feature flags
 -------------
 
 By default, this crate only compiles the shader translator.
-This should be cross-platform, and can be used with:
 
-```toml
-[dependencies]
-mozangle = "0.1"
-```
-
-The `egl` Cargo feature enables the EGL and OpenGL ES implementations.
-This is only supported on Windows, since the Direct3D 11 rendering backend is configured.
+In Windows, the `egl` Cargo feature enables the EGL and OpenGL ES implementations.
+Although upstream ANGLE supports more platforms,
+this crate only configures the Direct3D 11 rendering backend.
 
 ```toml
-[target.'cfg(windows)'.dependencies]
+[dependencies]
 mozangle = { version = "0.1", features = ["egl"] }
 ```
 

build.rs

@@ -12,19 +12,8 @@ fn main() {
 }
 
 fn build_angle() {
-    let egl = env::var("CARGO_FEATURE_EGL").is_ok();
     let target = env::var("TARGET").unwrap();
-    if egl && !target.contains("windows") {
-        println!("");
-        println!("The `egl` feature is only supported on Windows.");
-        println!("");
-        println!("Consider specifying your dependency like this:");
-        println!("");
-        println!("[target.'cfg(windows)'.dependencies]");
-        println!("mozangle = {{ version = \"0.1\" , features = [\"egl\"] }}");
-        println!("");
-        std::process::exit(1)
-    }
+    let egl = env::var("CARGO_FEATURE_EGL").is_ok() && target.contains("windows");
 
     let data = if egl { build_data::EGL } else { build_data::TRANSLATOR };
 
@@ -88,6 +77,11 @@ fn generate_bindings() {
     use gl_generator::{Registry, Api, Profile, Fallbacks};
     use std::fs::File;
 
+    let target = env::var("TARGET").unwrap();
+    if !target.contains("windows") {
+        return
+    }
+
     let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
 
     let mut file = File::create(&out_dir.join("egl_bindings.rs")).unwrap();

src/lib.rs

@@ -3,14 +3,14 @@
 pub mod shaders;
 #[cfg(test)] mod tests;
 
-#[cfg(feature = "egl")]
+#[cfg(all(windows, feature = "egl"))]
 pub mod gles {
     pub mod ffi {
         include!(concat!(env!("OUT_DIR"), "/gles_bindings.rs"));
     }
 }
 
-#[cfg(feature = "egl")]
+#[cfg(all(windows, feature = "egl"))]
 pub mod egl {
     use std::ffi::CString;
     use std::os::raw::c_void;

src/tests.rs

@@ -13,7 +13,7 @@ fn test_linkage() {
     init();
 }
 
-#[cfg(feature = "egl")]
+#[cfg(all(windows, feature = "egl"))]
 #[test]
 fn test_egl_linkage() {
     use egl::ffi;