Merge pull request #109 from Manishearth/android

Allow passing in Android paths

README.md

@@ -14,6 +14,11 @@ For some reason, the OpenSSL distribution for Windows is structured differently,
 1. Run `sudo apt-get install libssl-dev`.
 2. Run `cargo build`.
 
+###Android
+1. Follow the steps [here](wiki.openssl.org/index.php/Android) to build OpenSSL for android
+2. Provide the path to the libssl and libcrypto binaries via `$OPENSSL_PATH`
+3. Build the package with `cargo build`
+
 ###Windows
 
 1. Grab the latest Win32 OpenSSL installer [here][1]. At the time of this writing, it's v1.0.1i. If you're using 64-bit Rust (coming to Windows soon), then you should get the Win64 installer instead.

openssl-sys/src/build.rs

@@ -17,6 +17,16 @@ fn main() {
         if win_pos.is_some() {
            flags.push_str(" -l gdi32 -l wsock32");
         }
+
+        // Android doesn't have libcrypto/libssl,
+        // the toplevel Rust program should compile it themselves
+        if target.find_str("android").is_some() {
+            os::getenv("OPENSSL_PATH").expect("Android does not provide openssl libraries, please \
+                                               build them yourselves (instructions in the README) \
+                                               and provide their location through $OPENSSL_PATH.");
+            flags.push_str(" -L ${OPENSSL_PATH}");
+        }
+
         println!("cargo:rustc-flags={}", flags);
     }
 }