文档列表见：Rust 移动端跨平台复杂图形渲染项目开发系列总结（目录）
alloc_jemalloc
设置debug编译features
[features]
debug = []
复制代码build.rs学习
#![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");
}
}
复制代码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 {
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"), ×tamp) || !up_to_date(&src_dir, ×tamp) {
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);
}
复制代码