diff options
Diffstat (limited to 'cc/src/lib.rs')
| -rw-r--r-- | cc/src/lib.rs | 302 |
1 files changed, 269 insertions, 33 deletions
diff --git a/cc/src/lib.rs b/cc/src/lib.rs index 2d918b8..d795e5a 100644 --- a/cc/src/lib.rs +++ b/cc/src/lib.rs @@ -35,15 +35,13 @@ //! Cargo will also set this environment variable when executed with the `-jN` flag. //! //! If `NUM_JOBS` is not set, the `RAYON_NUM_THREADS` environment variable can -//! also specify the build paralellism. +//! also specify the build parallelism. //! //! # Examples //! //! Use the `Build` struct to compile `src/foo.c`: //! //! ```no_run -//! extern crate cc; -//! //! fn main() { //! cc::Build::new() //! .file("src/foo.c") @@ -58,9 +56,6 @@ #![allow(deprecated)] #![deny(missing_docs)] -#[cfg(feature = "parallel")] -extern crate rayon; - use std::collections::HashMap; use std::env; use std::ffi::{OsStr, OsString}; @@ -99,6 +94,8 @@ pub struct Build { flags: Vec<String>, flags_supported: Vec<String>, known_flag_support_status: Arc<Mutex<HashMap<String, bool>>>, + ar_flags: Vec<String>, + no_default_flags: bool, files: Vec<PathBuf>, cpp: bool, cpp_link_stdlib: Option<Option<String>>, @@ -109,6 +106,7 @@ pub struct Build { out_dir: Option<PathBuf>, opt_level: Option<String>, debug: Option<bool>, + force_frame_pointer: Option<bool>, env: Vec<(OsString, OsString)>, compiler: Option<PathBuf>, archiver: Option<PathBuf>, @@ -213,8 +211,17 @@ impl ToolFamily { } ToolFamily::Gnu | ToolFamily::Clang => { cmd.push_cc_arg("-g".into()); + } + } + } + + /// What the flag to force frame pointers. + fn add_force_frame_pointer(&self, cmd: &mut Tool) { + match *self { + ToolFamily::Gnu | ToolFamily::Clang => { cmd.push_cc_arg("-fno-omit-frame-pointer".into()); } + _ => (), } } @@ -277,6 +284,8 @@ impl Build { flags: Vec::new(), flags_supported: Vec::new(), known_flag_support_status: Arc::new(Mutex::new(HashMap::new())), + ar_flags: Vec::new(), + no_default_flags: false, files: Vec::new(), shared_flag: None, static_flag: None, @@ -289,6 +298,7 @@ impl Build { out_dir: None, opt_level: None, debug: None, + force_frame_pointer: None, env: Vec::new(), compiler: None, archiver: None, @@ -361,6 +371,23 @@ impl Build { self } + /// Add an arbitrary flag to the invocation of the compiler + /// + /// # Example + /// + /// ```no_run + /// cc::Build::new() + /// .file("src/foo.c") + /// .file("src/bar.c") + /// .ar_flag("/NODEFAULTLIB:libc.dll") + /// .compile("foo"); + /// ``` + + pub fn ar_flag(&mut self, flag: &str) -> &mut Build { + self.ar_flags.push(flag.to_string()); + self + } + fn ensure_check_file(&self) -> Result<PathBuf, Error> { let out_dir = self.get_out_dir()?; let src = if self.cuda { @@ -497,6 +524,17 @@ impl Build { self } + /// Disables the generation of default compiler flags. The default compiler + /// flags may cause conflicts in some cross compiling scenarios. + /// + /// Setting the `CRATE_CC_NO_DEFAULTS` environment variable has the same + /// effect as setting this to `true`. The presence of the environment + /// variable and the value of `no_default_flags` will be OR'd together. + pub fn no_default_flags(&mut self, no_default_flags: bool) -> &mut Build { + self.no_default_flags = no_default_flags; + self + } + /// Add a file which will be compiled pub fn file<P: AsRef<Path>>(&mut self, p: P) -> &mut Build { self.files.push(p.as_ref().to_path_buf()); @@ -750,6 +788,17 @@ impl Build { self } + /// Configures whether the compiler will emit instructions to store + /// frame pointers during codegen. + /// + /// This option is automatically enabled when debug information is emitted. + /// Otherwise the target platform compiler's default will be used. + /// You can use this option to force a specific setting. + pub fn force_frame_pointer(&mut self, force: bool) -> &mut Build { + self.force_frame_pointer = Some(force); + self + } + /// Configures the output directory where all object files and static /// libraries will be located. /// @@ -931,22 +980,150 @@ impl Build { } #[cfg(feature = "parallel")] - fn compile_objects(&self, objs: &[Object]) -> Result<(), Error> { - use self::rayon::prelude::*; + fn compile_objects<'me>(&'me self, objs: &[Object]) -> Result<(), Error> { + use std::sync::atomic::{AtomicBool, Ordering::SeqCst}; + use std::sync::Once; + + // Limit our parallelism globally with a jobserver. Start off by + // releasing our own token for this process so we can have a bit of an + // easier to write loop below. If this fails, though, then we're likely + // on Windows with the main implicit token, so we just have a bit extra + // parallelism for a bit and don't reacquire later. + let server = jobserver(); + let reacquire = server.release_raw().is_ok(); + + // When compiling objects in parallel we do a few dirty tricks to speed + // things up: + // + // * First is that we use the `jobserver` crate to limit the parallelism + // of this build script. The `jobserver` crate will use a jobserver + // configured by Cargo for build scripts to ensure that parallelism is + // coordinated across C compilations and Rust compilations. Before we + // compile anything we make sure to wait until we acquire a token. + // + // Note that this jobserver is cached globally so we only used one per + // process and only worry about creating it once. + // + // * Next we use a raw `thread::spawn` per thread to actually compile + // objects in parallel. We only actually spawn a thread after we've + // acquired a token to perform some work + // + // * Finally though we want to keep the dependencies of this crate + // pretty light, so we avoid using a safe abstraction like `rayon` and + // instead rely on some bits of `unsafe` code. We know that this stack + // frame persists while everything is compiling so we use all the + // stack-allocated objects without cloning/reallocating. We use a + // transmute to `State` with a `'static` lifetime to persist + // everything we need across the boundary, and the join-on-drop + // semantics of `JoinOnDrop` should ensure that our stack frame is + // alive while threads are alive. + // + // With all that in mind we compile all objects in a loop here, after we + // acquire the appropriate tokens, Once all objects have been compiled + // we join on all the threads and propagate the results of compilation. + // + // Note that as a slight optimization we try to break out as soon as + // possible as soon as any compilation fails to ensure that errors get + // out to the user as fast as possible. + let error = AtomicBool::new(false); + let mut threads = Vec::new(); + for obj in objs { + if error.load(SeqCst) { + break; + } + let token = server.acquire()?; + let state = State { + build: self, + obj, + error: &error, + }; + let state = unsafe { std::mem::transmute::<State, State<'static>>(state) }; + let thread = thread::spawn(|| { + let state: State<'me> = state; // erase the `'static` lifetime + let result = state.build.compile_object(state.obj); + if result.is_err() { + state.error.store(true, SeqCst); + } + drop(token); // make sure our jobserver token is released after the compile + return result; + }); + threads.push(JoinOnDrop(Some(thread))); + } - if let Some(amt) = self.getenv("NUM_JOBS") { - if let Ok(amt) = amt.parse() { - let _ = rayon::ThreadPoolBuilder::new() - .num_threads(amt) - .build_global(); + for mut thread in threads { + if let Some(thread) = thread.0.take() { + thread.join().expect("thread should not panic")?; } } - // Check for any errors and return the first one found. - objs.par_iter() - .with_max_len(1) - .map(|obj| self.compile_object(obj)) - .collect() + // Reacquire our process's token before we proceed, which we released + // before entering the loop above. + if reacquire { + server.acquire_raw()?; + } + + return Ok(()); + + /// Shared state from the parent thread to the child thread. This + /// package of pointers is temporarily transmuted to a `'static` + /// lifetime to cross the thread boundary and then once the thread is + /// running we erase the `'static` to go back to an anonymous lifetime. + struct State<'a> { + build: &'a Build, + obj: &'a Object, + error: &'a AtomicBool, + } + + /// Returns a suitable `jobserver::Client` used to coordinate + /// parallelism between build scripts. + fn jobserver() -> &'static jobserver::Client { + static INIT: Once = Once::new(); + static mut JOBSERVER: Option<jobserver::Client> = None; + + fn _assert_sync<T: Sync>() {} + _assert_sync::<jobserver::Client>(); + + unsafe { + INIT.call_once(|| { + let server = default_jobserver(); + JOBSERVER = Some(server); + }); + JOBSERVER.as_ref().unwrap() + } + } + + unsafe fn default_jobserver() -> jobserver::Client { + // Try to use the environmental jobserver which Cargo typically + // initializes for us... + if let Some(client) = jobserver::Client::from_env() { + return client; + } + + // ... but if that fails for whatever reason fall back to the number + // of cpus on the system or the `NUM_JOBS` env var. + let mut parallelism = num_cpus::get(); + if let Ok(amt) = env::var("NUM_JOBS") { + if let Ok(amt) = amt.parse() { + parallelism = amt; + } + } + + // If we create our own jobserver then be sure to reserve one token + // for ourselves. + let client = jobserver::Client::new(parallelism).expect("failed to create jobserver"); + client.acquire_raw().expect("failed to acquire initial"); + return client; + } + + struct JoinOnDrop(Option<thread::JoinHandle<Result<(), Error>>>); + + impl Drop for JoinOnDrop { + fn drop(&mut self) { + if let Some(thread) = self.0.take() { + drop(thread.join()); + } + } + } } #[cfg(not(feature = "parallel"))] @@ -1073,11 +1250,10 @@ impl Build { let mut cmd = self.get_base_compiler()?; let envflags = self.envflags(if self.cpp { "CXXFLAGS" } else { "CFLAGS" }); - // Disable default flag generation via environment variable or when - // certain cross compiling arguments are set - let use_defaults = self.getenv("CRATE_CC_NO_DEFAULTS").is_none(); + // Disable default flag generation via `no_default_flags` or environment variable + let no_defaults = self.no_default_flags || self.getenv("CRATE_CC_NO_DEFAULTS").is_some(); - if use_defaults { + if !no_defaults { self.add_default_flags(&mut cmd, &target, &opt_level)?; } else { println!("Info: default compiler flags are disabled"); @@ -1213,12 +1389,22 @@ impl Build { family.add_debug_flags(cmd); } + if self.get_force_frame_pointer() { + let family = cmd.family; + family.add_force_frame_pointer(cmd); + } + // Target flags match cmd.family { ToolFamily::Clang => { cmd.args.push(format!("--target={}", target).into()); } ToolFamily::Msvc { clang_cl } => { + // This is an undocumented flag from MSVC but helps with making + // builds more reproducible by avoiding putting timestamps into + // files. + cmd.args.push("-Brepro".into()); + if clang_cl { if target.contains("x86_64") { cmd.args.push("-m64".into()); @@ -1402,9 +1588,11 @@ impl Build { if let Some(arch) = parts.next() { let arch = &arch[5..]; cmd.args.push(("-march=rv".to_owned() + arch).into()); - // ABI is always soft-float right now, update this when this is no longer the - // case: - if arch.starts_with("64") { + if target.contains("linux") && arch.starts_with("64") { + cmd.args.push("-mabi=lp64d".into()); + } else if target.contains("linux") && arch.starts_with("32") { + cmd.args.push("-mabi=ilp32d".into()); + } else if arch.starts_with("64") { cmd.args.push("-mabi=lp64".into()); } else { cmd.args.push("-mabi=ilp32".into()); @@ -1501,6 +1689,9 @@ impl Build { let mut out = OsString::from("-out:"); out.push(dst); cmd.arg(out).arg("-nologo"); + for flag in self.ar_flags.iter() { + cmd.arg(flag); + } // Similar to https://github.com/rust-lang/rust/pull/47507 // and https://github.com/rust-lang/rust/pull/48548 @@ -1563,6 +1754,33 @@ impl Build { }; } else { let (mut ar, cmd) = self.get_ar()?; + + // Set an environment variable to tell the OSX archiver to ensure + // that all dates listed in the archive are zero, improving + // determinism of builds. AFAIK there's not really official + // documentation of this but there's a lot of references to it if + // you search google. + // + // You can reproduce this locally on a mac with: + // + // $ touch foo.c + // $ cc -c foo.c -o foo.o + // + // # Notice that these two checksums are different + // $ ar crus libfoo1.a foo.o && sleep 2 && ar crus libfoo2.a foo.o + // $ md5sum libfoo*.a + // + // # Notice that these two checksums are the same + // $ export ZERO_AR_DATE=1 + // $ ar crus libfoo1.a foo.o && sleep 2 && touch foo.o && ar crus libfoo2.a foo.o + // $ md5sum libfoo*.a + // + // In any case if this doesn't end up getting read, it shouldn't + // cause that many issues! + ar.env("ZERO_AR_DATE", "1"); + for flag in self.ar_flags.iter() { + ar.arg(flag); + } run( ar.arg("crs").arg(dst).args(&objects).args(&self.objects), &cmd, @@ -1687,13 +1905,19 @@ impl Build { let tool_opt: Option<Tool> = self .env_tool(env) - .map(|(tool, cc, args)| { + .map(|(tool, wrapper, args)| { + // find the driver mode, if any + const DRIVER_MODE: &str = "--driver-mode="; + let driver_mode = args + .iter() + .find(|a| a.starts_with(DRIVER_MODE)) + .map(|a| &a[DRIVER_MODE.len()..]); // chop off leading/trailing whitespace to work around // semi-buggy build scripts which are shared in // makefiles/configure scripts (where spaces are far more // lenient) - let mut t = Tool::new(PathBuf::from(tool.trim())); - if let Some(cc) = cc { + let mut t = Tool::with_clang_driver(PathBuf::from(tool.trim()), driver_mode); + if let Some(cc) = wrapper { t.cc_wrapper_path = Some(PathBuf::from(cc)); } for arg in args { @@ -1846,7 +2070,7 @@ impl Build { Err(_) => "nvcc".into(), Ok(nvcc) => nvcc, }; - let mut nvcc_tool = Tool::with_features(PathBuf::from(nvcc), self.cuda); + let mut nvcc_tool = Tool::with_features(PathBuf::from(nvcc), None, self.cuda); nvcc_tool .args .push(format!("-ccbin={}", tool.path.display()).into()); @@ -2062,6 +2286,10 @@ impl Build { }) } + fn get_force_frame_pointer(&self) -> bool { + self.force_frame_pointer.unwrap_or_else(|| self.get_debug()) + } + fn get_out_dir(&self) -> Result<PathBuf, Error> { match self.out_dir.clone() { Some(p) => Ok(p), @@ -2109,11 +2337,15 @@ impl Default for Build { } impl Tool { - fn new(path: PathBuf) -> Tool { - Tool::with_features(path, false) + fn new(path: PathBuf) -> Self { + Tool::with_features(path, None, false) } - fn with_features(path: PathBuf, cuda: bool) -> Tool { + fn with_clang_driver(path: PathBuf, clang_driver: Option<&str>) -> Self { + Self::with_features(path, clang_driver, false) + } + + fn with_features(path: PathBuf, clang_driver: Option<&str>, cuda: bool) -> Self { // Try to detect family of the tool from its name, falling back to Gnu. let family = if let Some(fname) = path.file_name().and_then(|p| p.to_str()) { if fname.contains("clang-cl") { @@ -2125,13 +2357,17 @@ impl Tool { { ToolFamily::Msvc { clang_cl: false } } else if fname.contains("clang") { - ToolFamily::Clang + match clang_driver { + Some("cl") => ToolFamily::Msvc { clang_cl: true }, + _ => ToolFamily::Clang, + } } else { ToolFamily::Gnu } } else { ToolFamily::Gnu }; + Tool { path: path, cc_wrapper_path: None, |