Rust build.rs進階學習

熊皮皮發表於2019-01-10
RustUI

文件列表見：Rust 移動端跨平臺複雜圖形渲染專案開發系列總結（目錄）

alloc_jemalloc

設定debug編譯features

[features]
debug = []
複製程式碼

build.rs學習

#![deny(warnings)]

extern crate build_helper;
extern crate cc;

use std::env;
use std::path::PathBuf;
use std::process::Command;
use build_helper::{run, native_lib_boilerplate};

fn main() {
    // FIXME: This is a hack to support building targets that don't
    // support jemalloc alongside hosts that do. The jemalloc build is
    // controlled by a feature of the std crate, and if that feature
    // changes between targets, it invalidates the fingerprint of
    // std's build script (this is a cargo bug); so we must ensure
    // that the feature set used by std is the same across all
    // targets, which means we have to build the alloc_jemalloc crate
    // for targets like emscripten, even if we don't use it.
    let target = env::var("TARGET").expect("TARGET was not set");
    let host = env::var("HOST").expect("HOST was not set");
    if target.contains("bitrig") || target.contains("emscripten") || target.contains("fuchsia") ||
       target.contains("msvc") || target.contains("openbsd") || target.contains("redox") ||
       target.contains("rumprun") || target.contains("wasm32") {
        println!("cargo:rustc-cfg=dummy_jemalloc");
        return;
    }

    // CloudABI ships with a copy of jemalloc that has been patched to
    // work well with sandboxing. Don't attempt to build our own copy,
    // as it won't build.
    if target.contains("cloudabi") {
        return;
    }

    if target.contains("android") {
        println!("cargo:rustc-link-lib=gcc");
    } else if !target.contains("windows") && !target.contains("musl") {
        println!("cargo:rustc-link-lib=pthread");
    }

    if let Some(jemalloc) = env::var_os("JEMALLOC_OVERRIDE") {
        let jemalloc = PathBuf::from(jemalloc);
        println!("cargo:rustc-link-search=native={}",
                 jemalloc.parent().unwrap().display());
        let stem = jemalloc.file_stem().unwrap().to_str().unwrap();
        let name = jemalloc.file_name().unwrap().to_str().unwrap();
        let kind = if name.ends_with(".a") {
            "static"
        } else {
            "dylib"
        };
        println!("cargo:rustc-link-lib={}={}", kind, &stem[3..]);
        return;
    }

    let link_name = if target.contains("windows") { "jemalloc" } else { "jemalloc_pic" };
    let native = match native_lib_boilerplate("jemalloc", "jemalloc", link_name, "lib") {
        Ok(native) => native,
        _ => return,
    };

    let mut cmd = Command::new("sh");
    cmd.arg(native.src_dir.join("configure")
                          .to_str()
                          .unwrap()
                          .replace("C:\\", "/c/")
                          .replace("\\", "/"))
       .current_dir(&native.out_dir)
       // jemalloc generates Makefile deps using GCC's "-MM" flag. This means
       // that GCC will run the preprocessor, and only the preprocessor, over
       // jemalloc's source files. If we don't specify CPPFLAGS, then at least
       // on ARM that step fails with a "Missing implementation for 32-bit
       // atomic operations" error. This is because no "-march" flag will be
       // passed to GCC, and then GCC won't define the
       // "__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4" macro that jemalloc needs to
       // select an atomic operation implementation.
       .env("CPPFLAGS", env::var_os("CFLAGS").unwrap_or_default());

    if target.contains("ios") {
        cmd.arg("--disable-tls");
    } else if target.contains("android") {
        // We force android to have prefixed symbols because apparently
        // replacement of the libc allocator doesn't quite work. When this was
        // tested (unprefixed symbols), it was found that the `realpath`
        // function in libc would allocate with libc malloc (not jemalloc
        // malloc), and then the standard library would free with jemalloc free,
        // causing a segfault.
        //
        // If the test suite passes, however, without symbol prefixes then we
        // should be good to go!
        cmd.arg("--with-jemalloc-prefix=je_");
        cmd.arg("--disable-tls");
    } else if target.contains("dragonfly") || target.contains("musl") {
        cmd.arg("--with-jemalloc-prefix=je_");
    }

    if cfg!(feature = "debug") {
        // Enable jemalloc assertions.
        cmd.arg("--enable-debug");
    }

    cmd.arg(format!("--host={}", build_helper::gnu_target(&target)));
    cmd.arg(format!("--build={}", build_helper::gnu_target(&host)));

    // for some reason, jemalloc configure doesn't detect this value
    // automatically for this target
    if target == "sparc64-unknown-linux-gnu" {
        cmd.arg("--with-lg-quantum=4");
    }

    run(&mut cmd);

    let mut make = Command::new(build_helper::make(&host));
    make.current_dir(&native.out_dir)
        .arg("build_lib_static");

    // These are intended for mingw32-make which we don't use
    if cfg!(windows) {
        make.env_remove("MAKEFLAGS").env_remove("MFLAGS");
    }

    // mingw make seems... buggy? unclear...
    if !host.contains("windows") {
        make.arg("-j")
            .arg(env::var("NUM_JOBS").expect("NUM_JOBS was not set"));
    }

    run(&mut make);

    // The pthread_atfork symbols is used by jemalloc on android but the really
    // old android we're building on doesn't have them defined, so just make
    // sure the symbols are available.
    if target.contains("androideabi") {
        println!("cargo:rerun-if-changed=pthread_atfork_dummy.c");
        cc::Build::new()
            .flag("-fvisibility=hidden")
            .file("pthread_atfork_dummy.c")
            .compile("pthread_atfork_dummy");
    }
}
複製程式碼

build_helper

use std::fs::File;
use std::path::{Path, PathBuf};
use std::process::{Command, Stdio};
use std::time::{SystemTime, UNIX_EPOCH};
use std::{env, fs};
use std::thread;

/// A helper macro to `unwrap` a result except also print out details like:
///
/// * The file/line of the panic
/// * The expression that failed
/// * The error itself
///
/// This is currently used judiciously throughout the build system rather than
/// using a `Result` with `try!`, but this may change one day...
#[macro_export]
macro_rules! t {
    ($e:expr) => {
        match $e {
            Ok(e) => e,
            Err(e) => panic!("{} failed with {}", stringify!($e), e),
        }
    };
}

pub fn run(cmd: &mut Command) {
    println!("running: {:?}", cmd);
    run_silent(cmd);
}

pub fn run_silent(cmd: &mut Command) {
    if !try_run_silent(cmd) {
        std::process::exit(1);
    }
}

pub fn try_run_silent(cmd: &mut Command) -> bool {
    let status = match cmd.status() {
        Ok(status) => status,
        Err(e) => fail(&format!(
            "failed to execute command: {:?}\nerror: {}",
            cmd, e
        )),
    };
    if !status.success() {
        println!(
            "\n\ncommand did not execute successfully: {:?}\n\
             expected success, got: {}\n\n",
            cmd, status
        );
    }
    status.success()
}

pub fn run_suppressed(cmd: &mut Command) {
    if !try_run_suppressed(cmd) {
        std::process::exit(1);
    }
}

pub fn try_run_suppressed(cmd: &mut Command) -> bool {
    let output = match cmd.output() {
        Ok(status) => status,
        Err(e) => fail(&format!(
            "failed to execute command: {:?}\nerror: {}",
            cmd, e
        )),
    };
    if !output.status.success() {
        println!(
            "\n\ncommand did not execute successfully: {:?}\n\
             expected success, got: {}\n\n\
             stdout ----\n{}\n\
             stderr ----\n{}\n\n",
            cmd,
            output.status,
            String::from_utf8_lossy(&output.stdout),
            String::from_utf8_lossy(&output.stderr)
        );
    }
    output.status.success()
}

pub fn gnu_target(target: &str) -> &str {
    match target {
        "i686-pc-windows-msvc" => "i686-pc-win32",
        "x86_64-pc-windows-msvc" => "x86_64-pc-win32",
        "i686-pc-windows-gnu" => "i686-w64-mingw32",
        "x86_64-pc-windows-gnu" => "x86_64-w64-mingw32",
        s => s,
    }
}

pub fn make(host: &str) -> PathBuf {
    if host.contains("bitrig") || host.contains("dragonfly") || host.contains("freebsd")
        || host.contains("netbsd") || host.contains("openbsd")
    {
        PathBuf::from("gmake")
    } else {
        PathBuf::from("make")
    }
}

pub fn output(cmd: &mut Command) -> String {
    let output = match cmd.stderr(Stdio::inherit()).output() {
        Ok(status) => status,
        Err(e) => fail(&format!(
            "failed to execute command: {:?}\nerror: {}",
            cmd, e
        )),
    };
    if !output.status.success() {
        panic!(
            "command did not execute successfully: {:?}\n\
             expected success, got: {}",
            cmd, output.status
        );
    }
    String::from_utf8(output.stdout).unwrap()
}

pub fn rerun_if_changed_anything_in_dir(dir: &Path) {
    let mut stack = dir.read_dir()
        .unwrap()
        .map(|e| e.unwrap())
        .filter(|e| &*e.file_name() != ".git")
        .collect::<Vec<_>>();
    while let Some(entry) = stack.pop() {
        let path = entry.path();
        if entry.file_type().unwrap().is_dir() {
            stack.extend(path.read_dir().unwrap().map(|e| e.unwrap()));
        } else {
            println!("cargo:rerun-if-changed={}", path.display());
        }
    }
}

/// Returns the last-modified time for `path`, or zero if it doesn't exist.
pub fn mtime(path: &Path) -> SystemTime {
    fs::metadata(path)
        .and_then(|f| f.modified())
        .unwrap_or(UNIX_EPOCH)
}

/// Returns whether `dst` is up to date given that the file or files in `src`
/// are used to generate it.
///
/// Uses last-modified time checks to verify this.
pub fn up_to_date(src: &Path, dst: &Path) -> bool {
    if !dst.exists() {
        return false;
    }
    let threshold = mtime(dst);
    let meta = match fs::metadata(src) {
        Ok(meta) => meta,
        Err(e) => panic!("source {:?} failed to get metadata: {}", src, e),
    };
    if meta.is_dir() {
        dir_up_to_date(src, threshold)
    } else {
        meta.modified().unwrap_or(UNIX_EPOCH) <= threshold
    }
}

#[must_use]
pub struct NativeLibBoilerplate {
    pub src_dir: PathBuf,
    pub out_dir: PathBuf,
}

impl NativeLibBoilerplate {
    /// On OSX we don't want to ship the exact filename that compiler-rt builds.
    /// This conflicts with the system and ours is likely a wildly different
    /// version, so they can't be substituted.
    ///
    /// As a result, we rename it here but we need to also use
    /// `install_name_tool` on OSX to rename the commands listed inside of it to
    /// ensure it's linked against correctly.
    pub fn fixup_sanitizer_lib_name(&self, sanitizer_name: &str) {
        if env::var("TARGET").unwrap() != "x86_64-apple-darwin" {
            return
        }

        let dir = self.out_dir.join("build/lib/darwin");
        let name = format!("clang_rt.{}_osx_dynamic", sanitizer_name);
        let src = dir.join(&format!("lib{}.dylib", name));
        let new_name = format!("lib__rustc__{}.dylib", name);
        let dst = dir.join(&new_name);

        println!("{} => {}", src.display(), dst.display());
        fs::rename(&src, &dst).unwrap();
        let status = Command::new("install_name_tool")
            .arg("-id")
            .arg(format!("@rpath/{}", new_name))
            .arg(&dst)
            .status()
            .expect("failed to execute `install_name_tool`");
        assert!(status.success());
    }
}

impl Drop for NativeLibBoilerplate {
    fn drop(&mut self) {
        if !thread::panicking() {
            t!(File::create(self.out_dir.join("rustbuild.timestamp")));
        }
    }
}

// Perform standard preparations for native libraries that are build only once for all stages.
// Emit rerun-if-changed and linking attributes for Cargo, check if any source files are
// updated, calculate paths used later in actual build with CMake/make or C/C++ compiler.
// If Err is returned, then everything is up-to-date and further build actions can be skipped.
// Timestamps are created automatically when the result of `native_lib_boilerplate` goes out
// of scope, so all the build actions should be completed until then.
pub fn native_lib_boilerplate(
    src_name: &str,
    out_name: &str,
    link_name: &str,
    search_subdir: &str,
) -> Result<NativeLibBoilerplate, ()> {
    let current_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
    let src_dir = current_dir.join("..").join(src_name);
    rerun_if_changed_anything_in_dir(&src_dir);

    let out_dir = env::var_os("RUSTBUILD_NATIVE_DIR").unwrap_or_else(||
        env::var_os("OUT_DIR").unwrap());
    let out_dir = PathBuf::from(out_dir).join(out_name);
    t!(fs::create_dir_all(&out_dir));
    if link_name.contains('=') {
        println!("cargo:rustc-link-lib={}", link_name);
    } else {
        println!("cargo:rustc-link-lib=static={}", link_name);
    }
    println!(
        "cargo:rustc-link-search=native={}",
        out_dir.join(search_subdir).display()
    );

    let timestamp = out_dir.join("rustbuild.timestamp");
    if !up_to_date(Path::new("build.rs"), &timestamp) || !up_to_date(&src_dir, &timestamp) {
        Ok(NativeLibBoilerplate {
            src_dir: src_dir,
            out_dir: out_dir,
        })
    } else {
        Err(())
    }
}

pub fn sanitizer_lib_boilerplate(sanitizer_name: &str)
    -> Result<(NativeLibBoilerplate, String), ()>
{
    let (link_name, search_path, apple) = match &*env::var("TARGET").unwrap() {
        "x86_64-unknown-linux-gnu" => (
            format!("clang_rt.{}-x86_64", sanitizer_name),
            "build/lib/linux",
            false,
        ),
        "x86_64-apple-darwin" => (
            format!("clang_rt.{}_osx_dynamic", sanitizer_name),
            "build/lib/darwin",
            true,
        ),
        _ => return Err(()),
    };
    let to_link = if apple {
        format!("dylib=__rustc__{}", link_name)
    } else {
        format!("static={}", link_name)
    };
    let lib = native_lib_boilerplate(
        "libcompiler_builtins/compiler-rt",
        sanitizer_name,
        &to_link,
        search_path,
    )?;
    Ok((lib, link_name))
}

fn dir_up_to_date(src: &Path, threshold: SystemTime) -> bool {
    t!(fs::read_dir(src)).map(|e| t!(e)).all(|e| {
        let meta = t!(e.metadata());
        if meta.is_dir() {
            dir_up_to_date(&e.path(), threshold)
        } else {
            meta.modified().unwrap_or(UNIX_EPOCH) < threshold
        }
    })
}

fn fail(s: &str) -> ! {
    println!("\n\n{}\n\n", s);
    std::process::exit(1);
}
複製程式碼

相關文章