diff options
Diffstat (limited to 'third_party/rust/cc/src/command_helpers.rs')
| -rw-r--r-- | third_party/rust/cc/src/command_helpers.rs | 433 |
1 files changed, 433 insertions, 0 deletions
diff --git a/third_party/rust/cc/src/command_helpers.rs b/third_party/rust/cc/src/command_helpers.rs new file mode 100644 index 0000000000..919d276c84 --- /dev/null +++ b/third_party/rust/cc/src/command_helpers.rs @@ -0,0 +1,433 @@ +//! Miscellaneous helpers for running commands + +use std::{ + collections::hash_map, + ffi::OsString, + fmt::Display, + fs, + hash::Hasher, + io::{self, Read, Write}, + path::Path, + process::{Child, ChildStderr, Command, Stdio}, + sync::{ + atomic::{AtomicBool, Ordering}, + Arc, + }, +}; + +use crate::{Error, ErrorKind, Object}; + +#[derive(Clone, Debug)] +pub(crate) struct CargoOutput { + pub(crate) metadata: bool, + pub(crate) warnings: bool, + pub(crate) debug: bool, + checked_dbg_var: Arc<AtomicBool>, +} + +impl CargoOutput { + pub(crate) fn new() -> Self { + Self { + metadata: true, + warnings: true, + debug: std::env::var_os("CC_ENABLE_DEBUG_OUTPUT").is_some(), + checked_dbg_var: Arc::new(AtomicBool::new(false)), + } + } + + pub(crate) fn print_metadata(&self, s: &dyn Display) { + if self.metadata { + println!("{}", s); + } + } + + pub(crate) fn print_warning(&self, arg: &dyn Display) { + if self.warnings { + println!("cargo:warning={}", arg); + } + } + + pub(crate) fn print_debug(&self, arg: &dyn Display) { + if self.metadata && !self.checked_dbg_var.load(Ordering::Relaxed) { + self.checked_dbg_var.store(true, Ordering::Relaxed); + println!("cargo:rerun-if-env-changed=CC_ENABLE_DEBUG_OUTPUT"); + } + if self.debug { + println!("{}", arg); + } + } + + fn stdio_for_warnings(&self) -> Stdio { + if self.warnings { + Stdio::piped() + } else { + Stdio::null() + } + } +} + +pub(crate) struct StderrForwarder { + inner: Option<(ChildStderr, Vec<u8>)>, + #[cfg(feature = "parallel")] + is_non_blocking: bool, + #[cfg(feature = "parallel")] + bytes_available_failed: bool, +} + +const MIN_BUFFER_CAPACITY: usize = 100; + +impl StderrForwarder { + pub(crate) fn new(child: &mut Child) -> Self { + Self { + inner: child + .stderr + .take() + .map(|stderr| (stderr, Vec::with_capacity(MIN_BUFFER_CAPACITY))), + #[cfg(feature = "parallel")] + is_non_blocking: false, + #[cfg(feature = "parallel")] + bytes_available_failed: false, + } + } + + #[allow(clippy::uninit_vec)] + fn forward_available(&mut self) -> bool { + if let Some((stderr, buffer)) = self.inner.as_mut() { + loop { + let old_data_end = buffer.len(); + + // For non-blocking we check to see if there is data available, so we should try to + // read at least that much. For blocking, always read at least the minimum amount. + #[cfg(not(feature = "parallel"))] + let to_reserve = MIN_BUFFER_CAPACITY; + #[cfg(feature = "parallel")] + let to_reserve = if self.is_non_blocking && !self.bytes_available_failed { + match crate::parallel::stderr::bytes_available(stderr) { + #[cfg(windows)] + Ok(0) => return false, + #[cfg(unix)] + Ok(0) => { + // On Unix, depending on the implementation, we may sometimes get 0 in a + // loop (either there is data available or the pipe is broken), so + // continue with the non-blocking read anyway. + MIN_BUFFER_CAPACITY + } + #[cfg(windows)] + Err(_) => { + // On Windows, if we get an error then the pipe is broken, so flush + // the buffer and bail. + if !buffer.is_empty() { + write_warning(&buffer[..]); + } + self.inner = None; + return true; + } + #[cfg(unix)] + Err(_) => { + // On Unix, depending on the implementation, we may get spurious + // errors so make a note not to use bytes_available again and try + // the non-blocking read anyway. + self.bytes_available_failed = true; + MIN_BUFFER_CAPACITY + } + Ok(bytes_available) => MIN_BUFFER_CAPACITY.max(bytes_available), + } + } else { + MIN_BUFFER_CAPACITY + }; + buffer.reserve(to_reserve); + + // SAFETY: 1) the length is set to the capacity, so we are never using memory beyond + // the underlying buffer and 2) we always call `truncate` below to set the len back + // to the initialized data. + unsafe { + buffer.set_len(buffer.capacity()); + } + match stderr.read(&mut buffer[old_data_end..]) { + Err(err) if err.kind() == std::io::ErrorKind::WouldBlock => { + // No data currently, yield back. + buffer.truncate(old_data_end); + return false; + } + Err(err) if err.kind() == std::io::ErrorKind::Interrupted => { + // Interrupted, try again. + buffer.truncate(old_data_end); + } + Ok(0) | Err(_) => { + // End of stream: flush remaining data and bail. + if old_data_end > 0 { + write_warning(&buffer[..old_data_end]); + } + self.inner = None; + return true; + } + Ok(bytes_read) => { + buffer.truncate(old_data_end + bytes_read); + let mut consumed = 0; + for line in buffer.split_inclusive(|&b| b == b'\n') { + // Only forward complete lines, leave the rest in the buffer. + if let Some((b'\n', line)) = line.split_last() { + consumed += line.len() + 1; + write_warning(line); + } + } + buffer.drain(..consumed); + } + } + } + } else { + true + } + } + + #[cfg(feature = "parallel")] + pub(crate) fn set_non_blocking(&mut self) -> Result<(), Error> { + assert!(!self.is_non_blocking); + + #[cfg(unix)] + if let Some((stderr, _)) = self.inner.as_ref() { + crate::parallel::stderr::set_non_blocking(stderr)?; + } + + self.is_non_blocking = true; + Ok(()) + } + + #[cfg(feature = "parallel")] + fn forward_all(&mut self) { + while !self.forward_available() {} + } + + #[cfg(not(feature = "parallel"))] + fn forward_all(&mut self) { + let forward_result = self.forward_available(); + assert!(forward_result, "Should have consumed all data"); + } +} + +fn write_warning(line: &[u8]) { + let stdout = io::stdout(); + let mut stdout = stdout.lock(); + stdout.write_all(b"cargo:warning=").unwrap(); + stdout.write_all(line).unwrap(); + stdout.write_all(b"\n").unwrap(); +} + +fn wait_on_child( + cmd: &Command, + program: &str, + child: &mut Child, + cargo_output: &CargoOutput, +) -> Result<(), Error> { + StderrForwarder::new(child).forward_all(); + + let status = match child.wait() { + Ok(s) => s, + Err(e) => { + return Err(Error::new( + ErrorKind::ToolExecError, + format!( + "Failed to wait on spawned child process, command {:?} with args {:?}: {}.", + cmd, program, e + ), + )); + } + }; + + cargo_output.print_debug(&status); + + if status.success() { + Ok(()) + } else { + Err(Error::new( + ErrorKind::ToolExecError, + format!( + "Command {:?} with args {:?} did not execute successfully (status code {}).", + cmd, program, status + ), + )) + } +} + +/// Find the destination object path for each file in the input source files, +/// and store them in the output Object. +pub(crate) fn objects_from_files(files: &[Arc<Path>], dst: &Path) -> Result<Vec<Object>, Error> { + let mut objects = Vec::with_capacity(files.len()); + for file in files { + let basename = file + .file_name() + .ok_or_else(|| { + Error::new( + ErrorKind::InvalidArgument, + "No file_name for object file path!", + ) + })? + .to_string_lossy(); + let dirname = file + .parent() + .ok_or_else(|| { + Error::new( + ErrorKind::InvalidArgument, + "No parent for object file path!", + ) + })? + .to_string_lossy(); + + // Hash the dirname. This should prevent conflicts if we have multiple + // object files with the same filename in different subfolders. + let mut hasher = hash_map::DefaultHasher::new(); + hasher.write(dirname.to_string().as_bytes()); + let obj = dst + .join(format!("{:016x}-{}", hasher.finish(), basename)) + .with_extension("o"); + + match obj.parent() { + Some(s) => fs::create_dir_all(s)?, + None => { + return Err(Error::new( + ErrorKind::InvalidArgument, + "dst is an invalid path with no parent", + )); + } + }; + + objects.push(Object::new(file.to_path_buf(), obj)); + } + + Ok(objects) +} + +pub(crate) fn run( + cmd: &mut Command, + program: &str, + cargo_output: &CargoOutput, +) -> Result<(), Error> { + let mut child = spawn(cmd, program, cargo_output)?; + wait_on_child(cmd, program, &mut child, cargo_output) +} + +pub(crate) fn run_output( + cmd: &mut Command, + program: &str, + cargo_output: &CargoOutput, +) -> Result<Vec<u8>, Error> { + cmd.stdout(Stdio::piped()); + + let mut child = spawn(cmd, program, cargo_output)?; + + let mut stdout = vec![]; + child + .stdout + .take() + .unwrap() + .read_to_end(&mut stdout) + .unwrap(); + + wait_on_child(cmd, program, &mut child, cargo_output)?; + + Ok(stdout) +} + +pub(crate) fn spawn( + cmd: &mut Command, + program: &str, + cargo_output: &CargoOutput, +) -> Result<Child, Error> { + struct ResetStderr<'cmd>(&'cmd mut Command); + + impl Drop for ResetStderr<'_> { + fn drop(&mut self) { + // Reset stderr to default to release pipe_writer so that print thread will + // not block forever. + self.0.stderr(Stdio::inherit()); + } + } + + cargo_output.print_debug(&format_args!("running: {:?}", cmd)); + + let cmd = ResetStderr(cmd); + let child = cmd.0.stderr(cargo_output.stdio_for_warnings()).spawn(); + match child { + Ok(child) => Ok(child), + Err(ref e) if e.kind() == io::ErrorKind::NotFound => { + let extra = if cfg!(windows) { + " (see https://github.com/rust-lang/cc-rs#compile-time-requirements \ +for help)" + } else { + "" + }; + Err(Error::new( + ErrorKind::ToolNotFound, + format!("Failed to find tool. Is `{}` installed?{}", program, extra), + )) + } + Err(e) => Err(Error::new( + ErrorKind::ToolExecError, + format!( + "Command {:?} with args {:?} failed to start: {:?}", + cmd.0, program, e + ), + )), + } +} + +pub(crate) fn command_add_output_file( + cmd: &mut Command, + dst: &Path, + cuda: bool, + msvc: bool, + clang: bool, + gnu: bool, + is_asm: bool, + is_arm: bool, +) { + if msvc && !clang && !gnu && !cuda && !(is_asm && is_arm) { + let mut s = OsString::from("-Fo"); + s.push(dst); + cmd.arg(s); + } else { + cmd.arg("-o").arg(dst); + } +} + +#[cfg(feature = "parallel")] +pub(crate) fn try_wait_on_child( + cmd: &Command, + program: &str, + child: &mut Child, + stdout: &mut dyn io::Write, + stderr_forwarder: &mut StderrForwarder, +) -> Result<Option<()>, Error> { + stderr_forwarder.forward_available(); + + match child.try_wait() { + Ok(Some(status)) => { + stderr_forwarder.forward_all(); + + let _ = writeln!(stdout, "{}", status); + + if status.success() { + Ok(Some(())) + } else { + Err(Error::new( + ErrorKind::ToolExecError, + format!( + "Command {:?} with args {:?} did not execute successfully (status code {}).", + cmd, program, status + ), + )) + } + } + Ok(None) => Ok(None), + Err(e) => { + stderr_forwarder.forward_all(); + Err(Error::new( + ErrorKind::ToolExecError, + format!( + "Failed to wait on spawned child process, command {:?} with args {:?}: {}.", + cmd, program, e + ), + )) + } + } +} |