libgit2-sys 0.3.6

extern crate pkg_config;
extern crate cmake;

use std::env;
use std::fs::{self, File};
use std::io::prelude::*;
use std::path::{Path, PathBuf};
use std::process::Command;

macro_rules! t {
    ($e:expr) => (match $e{
        Ok(e) => e,
        Err(e) => panic!("{} failed with {}", stringify!($e), e),
    })
}

fn main() {
    let https = env::var("CARGO_FEATURE_HTTPS").is_ok();
    let ssh = env::var("CARGO_FEATURE_SSH").is_ok();
    if ssh {
        register_dep("SSH2");
    }
    if https {
        register_dep("OPENSSL");
    }
    let has_pkgconfig = Command::new("pkg-config").output().is_ok();

    if env::var("LIBGIT2_SYS_USE_PKG_CONFIG").is_ok() {
        if pkg_config::find_library("libgit2").is_ok() {
            return
        }
    }

    let target = env::var("TARGET").unwrap();
    let windows = target.contains("windows");
    let msvc = target.contains("msvc");
    let mut cfg = cmake::Config::new("libgit2");

    if msvc {
        // libgit2 passes the /GL flag to enable whole program optimization, but
        // this requires that the /LTCG flag is passed to the linker later on,
        // and currently the compiler does not do that, so we disable whole
        // program optimization entirely.
        cfg.cflag("/GL-");

        // Currently liblibc links to msvcrt which apparently is a dynamic CRT,
        // so we need to turn this off to get it to link right.
        cfg.define("STATIC_CRT", "OFF");
    }

    // libgit2 uses pkg-config to discover libssh2, but this doesn't work on
    // windows as libssh2 doesn't come with a libssh2.pc file in that install
    // (or when pkg-config isn't found). As a result we just manually turn on
    // SSH support in libgit2 (a little jankily) here...
    if ssh && (windows || !has_pkgconfig) {
        if let Ok(libssh2_include) = env::var("DEP_SSH2_INCLUDE") {
            if msvc {
                cfg.cflag(format!("/I{}", libssh2_include))
                   .cflag("/DGIT_SSH");
            } else {
                cfg.cflag(format!("-I{}", libssh2_include))
                   .cflag("-DGIT_SSH");
            }
        }
    }

    if ssh {
        cfg.register_dep("SSH2");
    } else {
        cfg.define("USE_SSH", "OFF");
    }
    if https {
        cfg.register_dep("OPENSSL");
    } else {
        cfg.define("USE_OPENSSL", "OFF");
    }

    let _ = fs::remove_dir_all(env::var("OUT_DIR").unwrap());
    t!(fs::create_dir_all(env::var("OUT_DIR").unwrap()));

    let dst = cfg.define("BUILD_SHARED_LIBS", "OFF")
                 .define("BUILD_CLAR", "OFF")
                 .define("CURL", "OFF")
                 .register_dep("Z")
                 .build();

    // Make sure libssh2 was detected on unix systems, because it definitely
    // should have been!
    if ssh && !msvc {
        let flags = dst.join("build/CMakeFiles/git2.dir/flags.make");
        let mut contents = String::new();
        t!(t!(File::open(flags)).read_to_string(&mut contents));
        if !contents.contains("-DGIT_SSH") {
            panic!("libgit2 failed to find libssh2, and SSH support is required");
        }
    }

    if target.contains("windows") {
        println!("cargo:rustc-link-lib=winhttp");
        println!("cargo:rustc-link-lib=rpcrt4");
        println!("cargo:rustc-link-lib=ole32");
        println!("cargo:rustc-link-lib=crypt32");
        println!("cargo:rustc-link-lib=static=git2");
        println!("cargo:rustc-link-search=native={}/lib", dst.display());
        return
    }

    if env::var("HOST") == env::var("TARGET") {
        // libssh2 is linked in elsehwere, don't want it reported via pkg-config
        let pc = dst.join("lib/pkgconfig/libgit2.pc");
        let mut contents = String::new();
        t!(t!(File::open(&pc)).read_to_string(&mut contents));
        let contents = contents.replace(" -lssh2 ", " ");
        t!(t!(File::create(&pc)).write_all(contents.as_bytes()));

        prepend("PKG_CONFIG_PATH", dst.join("lib/pkgconfig"));
        if pkg_config::Config::new().statik(true).find("libgit2").is_ok() {
            return
        }
    }

    println!("cargo:rustc-link-lib=static=git2");
    println!("cargo:rustc-link-search=native={}", dst.join("lib").display());
    if target.contains("apple") {
        println!("cargo:rustc-link-lib=iconv");
    }
}

fn register_dep(dep: &str) {
    match env::var(&format!("DEP_{}_ROOT", dep)) {
        Ok(s) => {
            prepend("PKG_CONFIG_PATH", Path::new(&s).join("lib/pkgconfig"));
        }
        Err(..) => {}
    }
}

fn prepend(var: &str, val: PathBuf) {
    let prefix = env::var(var).unwrap_or(String::new());
    let mut v = vec![val];
    v.extend(env::split_paths(&prefix));
    env::set_var(var, &env::join_paths(v).unwrap());
}