//! A library for build scripts to compile custom C code
//!
//! This library is intended to be used as a `build-dependencies` entry in
//! `Cargo.toml`:
//!
//! ```toml
//! [build-dependencies]
//! cc = "1.0"
//! ```
//!
//! The purpose of this crate is to provide the utility functions necessary to
//! compile C code into a static archive which is then linked into a Rust crate.
//! Configuration is available through the `Build` struct.
//!
//! This crate will automatically detect situations such as cross compilation or
//! other environment variables set by Cargo and will build code appropriately.
//!
//! The crate is not limited to C code, it can accept any source code that can
//! be passed to a C or C++ compiler. As such, assembly files with extensions
//! `.s` (gcc/clang) and `.asm` (MSVC) can also be compiled.
//!
//! [`Build`]: struct.Build.html
//!
//! # Parallelism
//!
//! To parallelize computation, enable the `parallel` feature for the crate.
//!
//! ```toml
//! [build-dependencies]
//! cc = { version = "1.0", features = ["parallel"] }
//! ```
//! To specify the max number of concurrent compilation jobs, set the `NUM_JOBS`
//! environment variable to the desired amount.
//!
//! Cargo will also set this environment variable when executed with the `-jN` flag.
//!
//! # Examples
//!
//! Use the `Build` struct to compile `src/foo.c`:
//!
//! ```no_run
//! fn main() {
//! cc::Build::new()
//! .file("src/foo.c")
//! .define("FOO", Some("bar"))
//! .include("src")
//! .compile("foo");
//! }
//! ```
#![doc(html_root_url = "https://docs.rs/cc/1.0")]
#![cfg_attr(test, deny(warnings))]
#![allow(deprecated)]
#![deny(missing_docs)]
use std::borrow::Cow;
use std::collections::{hash_map, HashMap};
use std::env;
use std::ffi::{OsStr, OsString};
use std::fmt::{self, Display, Formatter};
use std::fs::{self, File};
use std::hash::Hasher;
use std::io::{self, BufRead, BufReader, Read, Write};
use std::path::{Component, Path, PathBuf};
use std::process::{Child, Command, Stdio};
use std::sync::{Arc, Mutex};
use std::thread::{self, JoinHandle};
mod os_pipe;
// These modules are all glue to support reading the MSVC version from
// the registry and from COM interfaces
#[cfg(windows)]
mod registry;
#[cfg(windows)]
#[macro_use]
mod winapi;
#[cfg(windows)]
mod com;
#[cfg(windows)]
mod setup_config;
#[cfg(windows)]
mod vs_instances;
#[cfg(windows)]
mod windows_sys;
pub mod windows_registry;
/// A builder for compilation of a native library.
///
/// A `Build` is the main type of the `cc` crate and is used to control all the
/// various configuration options and such of a compile. You'll find more
/// documentation on each method itself.
#[derive(Clone, Debug)]
pub struct Build {
include_directories: Vec<Arc<Path>>,
definitions: Vec<(Arc<str>, Option<Arc<str>>)>,
objects: Vec<Arc<Path>>,
flags: Vec<Arc<str>>,
flags_supported: Vec<Arc<str>>,
known_flag_support_status: Arc<Mutex<HashMap<String, bool>>>,
ar_flags: Vec<Arc<str>>,
asm_flags: Vec<Arc<str>>,
no_default_flags: bool,
files: Vec<Arc<Path>>,
cpp: bool,
cpp_link_stdlib: Option<Option<Arc<str>>>,
cpp_set_stdlib: Option<Arc<str>>,
cuda: bool,
cudart: Option<Arc<str>>,
std: Option<Arc<str>>,
target: Option<Arc<str>>,
host: Option<Arc<str>>,
out_dir: Option<Arc<Path>>,
opt_level: Option<Arc<str>>,
debug: Option<bool>,
force_frame_pointer: Option<bool>,
env: Vec<(Arc<OsStr>, Arc<OsStr>)>,
compiler: Option<Arc<Path>>,
archiver: Option<Arc<Path>>,
ranlib: Option<Arc<Path>>,
cargo_metadata: bool,
link_lib_modifiers: Vec<Arc<str>>,
pic: Option<bool>,
use_plt: Option<bool>,
static_crt: Option<bool>,
shared_flag: Option<bool>,
static_flag: Option<bool>,
warnings_into_errors: bool,
warnings: Option<bool>,
extra_warnings: Option<bool>,
env_cache: Arc<Mutex<HashMap<String, Option<Arc<str>>>>>,
apple_sdk_root_cache: Arc<Mutex<HashMap<String, OsString>>>,
emit_rerun_if_env_changed: bool,
}
/// Represents the types of errors that may occur while using cc-rs.
#[derive(Clone, Debug)]
enum ErrorKind {
/// Error occurred while performing I/O.
IOError,
/// Invalid architecture supplied.
ArchitectureInvalid,
/// Environment variable not found, with the var in question as extra info.
EnvVarNotFound,
/// Error occurred while using external tools (ie: invocation of compiler).
ToolExecError,
/// Error occurred due to missing external tools.
ToolNotFound,
/// One of the function arguments failed validation.
InvalidArgument,
}
/// Represents an internal error that occurred, with an explanation.
#[derive(Clone, Debug)]
pub struct Error {
/// Describes the kind of error that occurred.
kind: ErrorKind,
/// More explanation of error that occurred.
message: Cow<'static, str>,
}
impl Error {
fn new(kind: ErrorKind, message: impl Into<Cow<'static, str>>) -> Error {
Error {
kind,
message: message.into(),
}
}
}
impl From<io::Error> for Error {
fn from(e: io::Error) -> Error {
Error::new(ErrorKind::IOError, format!("{}", e))
}
}
impl Display for Error {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{:?}: {}", self.kind, self.message)
}
}
impl std::error::Error for Error {}
/// Configuration used to represent an invocation of a C compiler.
///
/// This can be used to figure out what compiler is in use, what the arguments
/// to it are, and what the environment variables look like for the compiler.
/// This can be used to further configure other build systems (e.g. forward
/// along CC and/or CFLAGS) or the `to_command` method can be used to run the
/// compiler itself.
#[derive(Clone, Debug)]
pub struct Tool {
path: PathBuf,
cc_wrapper_path: Option<PathBuf>,
cc_wrapper_args: Vec<OsString>,
args: Vec<OsString>,
env: Vec<(OsString, OsString)>,
family: ToolFamily,
cuda: bool,
removed_args: Vec<OsString>,
}
/// Represents the family of tools this tool belongs to.
///
/// Each family of tools differs in how and what arguments they accept.
///
/// Detection of a family is done on best-effort basis and may not accurately reflect the tool.
#[derive(Copy, Clone, Debug, PartialEq)]
enum ToolFamily {
/// Tool is GNU Compiler Collection-like.
Gnu,
/// Tool is Clang-like. It differs from the GCC in a sense that it accepts superset of flags
/// and its cross-compilation approach is different.
Clang,
/// Tool is the MSVC cl.exe.
Msvc { clang_cl: bool },
}
impl ToolFamily {
/// What the flag to request debug info for this family of tools look like
fn add_debug_flags(&self, cmd: &mut Tool, dwarf_version: Option<u32>) {
match *self {
ToolFamily::Msvc { .. } => {
cmd.push_cc_arg("-Z7".into());
}
ToolFamily::Gnu | ToolFamily::Clang => {
cmd.push_cc_arg(
dwarf_version
.map_or_else(|| "-g".into(), |v| format!("-gdwarf-{}", v))
.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());
}
_ => (),
}
}
/// What the flags to enable all warnings
fn warnings_flags(&self) -> &'static str {
match *self {
ToolFamily::Msvc { .. } => "-W4",
ToolFamily::Gnu | ToolFamily::Clang => "-Wall",
}
}
/// What the flags to enable extra warnings
fn extra_warnings_flags(&self) -> Option<&'static str> {
match *self {
ToolFamily::Msvc { .. } => None,
ToolFamily::Gnu | ToolFamily::Clang => Some("-Wextra"),
}
}
/// What the flag to turn warning into errors
fn warnings_to_errors_flag(&self) -> &'static str {
match *self {
ToolFamily::Msvc { .. } => "-WX",
ToolFamily::Gnu | ToolFamily::Clang => "-Werror",
}
}
fn verbose_stderr(&self) -> bool {
*self == ToolFamily::Clang
}
}
/// Represents an object.
///
/// This is a source file -> object file pair.
#[derive(Clone, Debug)]
struct Object {
src: PathBuf,
dst: PathBuf,
}
impl Object {
/// Create a new source file -> object file pair.
fn new(src: PathBuf, dst: PathBuf) -> Object {
Object { src: src, dst: dst }
}
}
impl Build {
/// Construct a new instance of a blank set of configuration.
///
/// This builder is finished with the [`compile`] function.
///
/// [`compile`]: struct.Build.html#method.compile
pub fn new() -> Build {
Build {
include_directories: Vec::new(),
definitions: Vec::new(),
objects: Vec::new(),
flags: Vec::new(),
flags_supported: Vec::new(),
known_flag_support_status: Arc::new(Mutex::new(HashMap::new())),
ar_flags: Vec::new(),
asm_flags: Vec::new(),
no_default_flags: false,
files: Vec::new(),
shared_flag: None,
static_flag: None,
cpp: false,
cpp_link_stdlib: None,
cpp_set_stdlib: None,
cuda: false,
cudart: None,
std: None,
target: None,
host: None,
out_dir: None,
opt_level: None,
debug: None,
force_frame_pointer: None,
env: Vec::new(),
compiler: None,
archiver: None,
ranlib: None,
cargo_metadata: true,
link_lib_modifiers: Vec::new(),
pic: None,
use_plt: None,
static_crt: None,
warnings: None,
extra_warnings: None,
warnings_into_errors: false,
env_cache: Arc::new(Mutex::new(HashMap::new())),
apple_sdk_root_cache: Arc::new(Mutex::new(HashMap::new())),
emit_rerun_if_env_changed: true,
}
}
/// Add a directory to the `-I` or include path for headers
///
/// # Example
///
/// ```no_run
/// use std::path::Path;
///
/// let library_path = Path::new("/path/to/library");
///
/// cc::Build::new()
/// .file("src/foo.c")
/// .include(library_path)
/// .include("src")
/// .compile("foo");
/// ```
pub fn include<P: AsRef<Path>>(&mut self, dir: P) -> &mut Build {
self.include_directories.push(dir.as_ref().into());
self
}
/// Add multiple directories to the `-I` include path.
///
/// # Example
///
/// ```no_run
/// # use std::path::Path;
/// # let condition = true;
/// #
/// let mut extra_dir = None;
/// if condition {
/// extra_dir = Some(Path::new("/path/to"));
/// }
///
/// cc::Build::new()
/// .file("src/foo.c")
/// .includes(extra_dir)
/// .compile("foo");
/// ```
pub fn includes<P>(&mut self, dirs: P) -> &mut Build
where
P: IntoIterator,
P::Item: AsRef<Path>,
{
for dir in dirs {
self.include(dir);
}
self
}
/// Specify a `-D` variable with an optional value.
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .define("FOO", "BAR")
/// .define("BAZ", None)
/// .compile("foo");
/// ```
pub fn define<'a, V: Into<Option<&'a str>>>(&mut self, var: &str, val: V) -> &mut Build {
self.definitions
.push((var.into(), val.into().map(Into::into)));
self
}
/// Add an arbitrary object file to link in
pub fn object<P: AsRef<Path>>(&mut self, obj: P) -> &mut Build {
self.objects.push(obj.as_ref().into());
self
}
/// Add an arbitrary flag to the invocation of the compiler
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .flag("-ffunction-sections")
/// .compile("foo");
/// ```
pub fn flag(&mut self, flag: &str) -> &mut Build {
self.flags.push(flag.into());
self
}
/// Add a flag to the invocation of the ar
///
/// # 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.into());
self
}
/// Add a flag that will only be used with assembly files.
///
/// The flag will be applied to input files with either a `.s` or
/// `.asm` extension (case insensitive).
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .asm_flag("-Wa,-defsym,abc=1")
/// .file("src/foo.S") // The asm flag will be applied here
/// .file("src/bar.c") // The asm flag will not be applied here
/// .compile("foo");
/// ```
pub fn asm_flag(&mut self, flag: &str) -> &mut Build {
self.asm_flags.push(flag.into());
self
}
fn ensure_check_file(&self) -> Result<PathBuf, Error> {
let out_dir = self.get_out_dir()?;
let src = if self.cuda {
assert!(self.cpp);
out_dir.join("flag_check.cu")
} else if self.cpp {
out_dir.join("flag_check.cpp")
} else {
out_dir.join("flag_check.c")
};
if !src.exists() {
let mut f = fs::File::create(&src)?;
write!(f, "int main(void) {{ return 0; }}")?;
}
Ok(src)
}
/// Run the compiler to test if it accepts the given flag.
///
/// For a convenience method for setting flags conditionally,
/// see `flag_if_supported()`.
///
/// It may return error if it's unable to run the compiler with a test file
/// (e.g. the compiler is missing or a write to the `out_dir` failed).
///
/// Note: Once computed, the result of this call is stored in the
/// `known_flag_support` field. If `is_flag_supported(flag)`
/// is called again, the result will be read from the hash table.
pub fn is_flag_supported(&self, flag: &str) -> Result<bool, Error> {
let mut known_status = self.known_flag_support_status.lock().unwrap();
if let Some(is_supported) = known_status.get(flag).cloned() {
return Ok(is_supported);
}
let out_dir = self.get_out_dir()?;
let src = self.ensure_check_file()?;
let obj = out_dir.join("flag_check");
let target = self.get_target()?;
let host = self.get_host()?;
let mut cfg = Build::new();
cfg.flag(flag)
.target(&target)
.opt_level(0)
.host(&host)
.debug(false)
.cpp(self.cpp)
.cuda(self.cuda);
if let Some(ref c) = self.compiler {
cfg.compiler(c.clone());
}
let mut compiler = cfg.try_get_compiler()?;
// Clang uses stderr for verbose output, which yields a false positive
// result if the CFLAGS/CXXFLAGS include -v to aid in debugging.
if compiler.family.verbose_stderr() {
compiler.remove_arg("-v".into());
}
let mut cmd = compiler.to_command();
let is_arm = target.contains("aarch64") || target.contains("arm");
let clang = compiler.family == ToolFamily::Clang;
let gnu = compiler.family == ToolFamily::Gnu;
command_add_output_file(
&mut cmd,
&obj,
self.cuda,
target.contains("msvc"),
clang,
gnu,
false,
is_arm,
);
// We need to explicitly tell msvc not to link and create an exe
// in the root directory of the crate
if target.contains("msvc") && !self.cuda {
cmd.arg("-c");
}
cmd.arg(&src);
let output = cmd.output()?;
let is_supported = output.status.success() && output.stderr.is_empty();
known_status.insert(flag.to_owned(), is_supported);
Ok(is_supported)
}
/// Add an arbitrary flag to the invocation of the compiler if it supports it
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .flag_if_supported("-Wlogical-op") // only supported by GCC
/// .flag_if_supported("-Wunreachable-code") // only supported by clang
/// .compile("foo");
/// ```
pub fn flag_if_supported(&mut self, flag: &str) -> &mut Build {
self.flags_supported.push(flag.into());
self
}
/// Add flags from the specified environment variable.
///
/// Normally the `cc` crate will consult with the standard set of environment
/// variables (such as `CFLAGS` and `CXXFLAGS`) to construct the compiler invocation. Use of
/// this method provides additional levers for the end user to use when configuring the build
/// process.
///
/// Just like the standard variables, this method will search for an environment variable with
/// appropriate target prefixes, when appropriate.
///
/// # Examples
///
/// This method is particularly beneficial in introducing the ability to specify crate-specific
/// flags.
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .try_flags_from_environment(concat!(env!("CARGO_PKG_NAME"), "_CFLAGS"))
/// .expect("the environment variable must be specified and UTF-8")
/// .compile("foo");
/// ```
///
pub fn try_flags_from_environment(&mut self, environ_key: &str) -> Result<&mut Build, Error> {
let flags = self.envflags(environ_key)?;
self.flags.extend(flags.into_iter().map(Into::into));
Ok(self)
}
/// Set the `-shared` flag.
///
/// When enabled, the compiler will produce a shared object which can
/// then be linked with other objects to form an executable.
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .shared_flag(true)
/// .compile("libfoo.so");
/// ```
pub fn shared_flag(&mut self, shared_flag: bool) -> &mut Build {
self.shared_flag = Some(shared_flag);
self
}
/// Set the `-static` flag.
///
/// When enabled on systems that support dynamic linking, this prevents
/// linking with the shared libraries.
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .shared_flag(true)
/// .static_flag(true)
/// .compile("foo");
/// ```
pub fn static_flag(&mut self, static_flag: bool) -> &mut Build {
self.static_flag = Some(static_flag);
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().into());
self
}
/// Add files which will be compiled
pub fn files<P>(&mut self, p: P) -> &mut Build
where
P: IntoIterator,
P::Item: AsRef<Path>,
{
for file in p.into_iter() {
self.file(file);
}
self
}
/// Set C++ support.
///
/// The other `cpp_*` options will only become active if this is set to
/// `true`.
///
/// The name of the C++ standard library to link is decided by:
/// 1. If [cpp_link_stdlib](Build::cpp_link_stdlib) is set, use its value.
/// 2. Else if the `CXXSTDLIB` environment variable is set, use its value.
/// 3. Else the default is `libc++` for OS X and BSDs, `libc++_shared` for Android,
/// `None` for MSVC and `libstdc++` for anything else.
pub fn cpp(&mut self, cpp: bool) -> &mut Build {
self.cpp = cpp;
self
}
/// Set CUDA C++ support.
///
/// Enabling CUDA will invoke the CUDA compiler, NVCC. While NVCC accepts
/// the most common compiler flags, e.g. `-std=c++17`, some project-specific
/// flags might have to be prefixed with "-Xcompiler" flag, for example as
/// `.flag("-Xcompiler").flag("-fpermissive")`. See the documentation for
/// `nvcc`, the CUDA compiler driver, at https://docs.nvidia.com/cuda/cuda-compiler-driver-nvcc/
/// for more information.
///
/// If enabled, this also implicitly enables C++ support.
pub fn cuda(&mut self, cuda: bool) -> &mut Build {
self.cuda = cuda;
if cuda {
self.cpp = true;
self.cudart = Some("static".into());
}
self
}
/// Link CUDA run-time.
///
/// This option mimics the `--cudart` NVCC command-line option. Just like
/// the original it accepts `{none|shared|static}`, with default being
/// `static`. The method has to be invoked after `.cuda(true)`, or not
/// at all, if the default is right for the project.
pub fn cudart(&mut self, cudart: &str) -> &mut Build {
if self.cuda {
self.cudart = Some(cudart.into());
}
self
}
/// Specify the C or C++ language standard version.
///
/// These values are common to modern versions of GCC, Clang and MSVC:
/// - `c11` for ISO/IEC 9899:2011
/// - `c17` for ISO/IEC 9899:2018
/// - `c++14` for ISO/IEC 14882:2014
/// - `c++17` for ISO/IEC 14882:2017
/// - `c++20` for ISO/IEC 14882:2020
///
/// Other values have less broad support, e.g. MSVC does not support `c++11`
/// (`c++14` is the minimum), `c89` (omit the flag instead) or `c99`.
///
/// For compiling C++ code, you should also set `.cpp(true)`.
///
/// The default is that no standard flag is passed to the compiler, so the
/// language version will be the compiler's default.
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/modern.cpp")
/// .cpp(true)
/// .std("c++17")
/// .compile("modern");
/// ```
pub fn std(&mut self, std: &str) -> &mut Build {
self.std = Some(std.into());
self
}
/// Set warnings into errors flag.
///
/// Disabled by default.
///
/// Warning: turning warnings into errors only make sense
/// if you are a developer of the crate using cc-rs.
/// Some warnings only appear on some architecture or
/// specific version of the compiler. Any user of this crate,
/// or any other crate depending on it, could fail during
/// compile time.
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .warnings_into_errors(true)
/// .compile("libfoo.a");
/// ```
pub fn warnings_into_errors(&mut self, warnings_into_errors: bool) -> &mut Build {
self.warnings_into_errors = warnings_into_errors;
self
}
/// Set warnings flags.
///
/// Adds some flags:
/// - "-Wall" for MSVC.
/// - "-Wall", "-Wextra" for GNU and Clang.
///
/// Enabled by default.
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .warnings(false)
/// .compile("libfoo.a");
/// ```
pub fn warnings(&mut self, warnings: bool) -> &mut Build {
self.warnings = Some(warnings);
self.extra_warnings = Some(warnings);
self
}
/// Set extra warnings flags.
///
/// Adds some flags:
/// - nothing for MSVC.
/// - "-Wextra" for GNU and Clang.
///
/// Enabled by default.
///
/// # Example
///
/// ```no_run
/// // Disables -Wextra, -Wall remains enabled:
/// cc::Build::new()
/// .file("src/foo.c")
/// .extra_warnings(false)
/// .compile("libfoo.a");
/// ```
pub fn extra_warnings(&mut self, warnings: bool) -> &mut Build {
self.extra_warnings = Some(warnings);
self
}
/// Set the standard library to link against when compiling with C++
/// support.
///
/// If the `CXXSTDLIB` environment variable is set, its value will
/// override the default value, but not the value explicitly set by calling
/// this function.
///
/// A value of `None` indicates that no automatic linking should happen,
/// otherwise cargo will link against the specified library.
///
/// The given library name must not contain the `lib` prefix.
///
/// Common values:
/// - `stdc++` for GNU
/// - `c++` for Clang
/// - `c++_shared` or `c++_static` for Android
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .shared_flag(true)
/// .cpp_link_stdlib("stdc++")
/// .compile("libfoo.so");
/// ```
pub fn cpp_link_stdlib<'a, V: Into<Option<&'a str>>>(
&mut self,
cpp_link_stdlib: V,
) -> &mut Build {
self.cpp_link_stdlib = Some(cpp_link_stdlib.into().map(|s| s.into()));
self
}
/// Force the C++ compiler to use the specified standard library.
///
/// Setting this option will automatically set `cpp_link_stdlib` to the same
/// value.
///
/// The default value of this option is always `None`.
///
/// This option has no effect when compiling for a Visual Studio based
/// target.
///
/// This option sets the `-stdlib` flag, which is only supported by some
/// compilers (clang, icc) but not by others (gcc). The library will not
/// detect which compiler is used, as such it is the responsibility of the
/// caller to ensure that this option is only used in conjunction with a
/// compiler which supports the `-stdlib` flag.
///
/// A value of `None` indicates that no specific C++ standard library should
/// be used, otherwise `-stdlib` is added to the compile invocation.
///
/// The given library name must not contain the `lib` prefix.
///
/// Common values:
/// - `stdc++` for GNU
/// - `c++` for Clang
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .cpp_set_stdlib("c++")
/// .compile("libfoo.a");
/// ```
pub fn cpp_set_stdlib<'a, V: Into<Option<&'a str>>>(
&mut self,
cpp_set_stdlib: V,
) -> &mut Build {
let cpp_set_stdlib = cpp_set_stdlib.into();
self.cpp_set_stdlib = cpp_set_stdlib.map(|s| s.into());
self.cpp_link_stdlib(cpp_set_stdlib);
self
}
/// Configures the target this configuration will be compiling for.
///
/// This option is automatically scraped from the `TARGET` environment
/// variable by build scripts, so it's not required to call this function.
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .target("aarch64-linux-android")
/// .compile("foo");
/// ```
pub fn target(&mut self, target: &str) -> &mut Build {
self.target = Some(target.into());
self
}
/// Configures the host assumed by this configuration.
///
/// This option is automatically scraped from the `HOST` environment
/// variable by build scripts, so it's not required to call this function.
///
/// # Example
///
/// ```no_run
/// cc::Build::new()
/// .file("src/foo.c")
/// .host("arm-linux-gnueabihf")
/// .compile("foo");
/// ```
pub fn host(&mut self, host: &str) -> &mut Build {
self.host = Some(host.into());
self
}
/// Configures the optimization level of the generated object files.
///
/// This option is automatically scraped from the `OPT_LEVEL` environment
/// variable by build scripts, so it's not required to call this function.
pub fn opt_level(&mut self, opt_level: u32) -> &mut Build {
self.opt_level = Some(opt_level.to_string().into());
self
}
/// Configures the optimization level of the generated object files.
///
/// This option is automatically scraped from the `OPT_LEVEL` environment
/// variable by build scripts, so it's not required to call this function.
pub fn opt_level_str(&mut self, opt_level: &str) -> &mut Build {
self.opt_level = Some(opt_level.into());
self
}
/// Configures whether the compiler will emit debug information when
/// generating object files.
///
/// This option is automatically scraped from the `DEBUG` environment
/// variable by build scripts, so it's not required to call this function.
pub fn debug(&mut self, debug: bool) -> &mut Build {
self.debug = Some(debug);
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.
///
/// This option is automatically scraped from the `OUT_DIR` environment
/// variable by build scripts, so it's not required to call this function.
pub fn out_dir<P: AsRef<Path>>(&mut self, out_dir: P) -> &mut Build {
self.out_dir = Some(out_dir.as_ref().into());
self
}
/// Configures the compiler to be used to produce output.
///
/// This option is automatically determined from the target platform or a
/// number of environment variables, so it's not required to call this
/// function.
pub fn compiler<P: AsRef<Path>>(&mut self, compiler: P) -> &mut Build {
self.compiler = Some(compiler.as_ref().into());
self
}
/// Configures the tool used to assemble archives.
///
/// This option is automatically determined from the target platform or a
/// number of environment variables, so it's not required to call this
/// function.
pub fn archiver<P: AsRef<Path>>(&mut self, archiver: P) -> &mut Build {
self.archiver = Some(archiver.as_ref().into());
self
}
/// Configures the tool used to index archives.
///
/// This option is automatically determined from the target platform or a
/// number of environment variables, so it's not required to call this
/// function.
pub fn ranlib<P: AsRef<Path>>(&mut self, ranlib: P) -> &mut Build {
self.ranlib = Some(ranlib.as_ref().into());
self
}
/// Define whether metadata should be emitted for cargo allowing it to
/// automatically link the binary. Defaults to `true`.
///
/// The emitted metadata is:
///
/// - `rustc-link-lib=static=`*compiled lib*
/// - `rustc-link-search=native=`*target folder*
/// - When target is MSVC, the ATL-MFC libs are added via `rustc-link-search=native=`
/// - When C++ is enabled, the C++ stdlib is added via `rustc-link-lib`
/// - If `emit_rerun_if_env_changed` is not `false`, `rerun-if-env-changed=`*env*
///
pub fn cargo_metadata(&mut self, cargo_metadata: bool) -> &mut Build {
self.cargo_metadata = cargo_metadata;
self
}
/// Adds a native library modifier that will be added to the
/// `rustc-link-lib=static:MODIFIERS=LIBRARY_NAME` metadata line
/// emitted for cargo if `cargo_metadata` is enabled.
/// See https://doc.rust-lang.org/rustc/command-line-arguments.html#-l-link-the-generated-crate-to-a-native-library
/// for the list of modifiers accepted by rustc.
pub fn link_lib_modifier(&mut self, link_lib_modifier: &str) -> &mut Build {
self.link_lib_modifiers.push(link_lib_modifier.into());
self
}
/// Configures whether the compiler will emit position independent code.
///
/// This option defaults to `false` for `windows-gnu` and bare metal targets and
/// to `true` for all other targets.
pub fn pic(&mut self, pic: bool) -> &mut Build {
self.pic = Some(pic);
self
}
/// Configures whether the Procedure Linkage Table is used for indirect
/// calls into shared libraries.
///
/// The PLT is used to provide features like lazy binding, but introduces
/// a small performance loss due to extra pointer indirection. Setting
/// `use_plt` to `false` can provide a small performance increase.
///
/// Note that skipping the PLT requires a recent version of GCC/Clang.
///
/// This only applies to ELF targets. It has no effect on other platforms.
pub fn use_plt(&mut self, use_plt: bool) -> &mut Build {
self.use_plt = Some(use_plt);
self
}
/// Define whether metadata should be emitted for cargo to detect environment
/// changes that should trigger a rebuild.
///
/// This has no effect if the `cargo_metadata` option is `false`.
///
/// This option defaults to `true`.
pub fn emit_rerun_if_env_changed(&mut self, emit_rerun_if_env_changed: bool) -> &mut Build {
self.emit_rerun_if_env_changed = emit_rerun_if_env_changed;
self
}
/// Configures whether the /MT flag or the /MD flag will be passed to msvc build tools.
///
/// This option defaults to `false`, and affect only msvc targets.
pub fn static_crt(&mut self, static_crt: bool) -> &mut Build {
self.static_crt = Some(static_crt);
self
}
#[doc(hidden)]
pub fn __set_env<A, B>(&mut self, a: A, b: B) -> &mut Build
where
A: AsRef<OsStr>,
B: AsRef<OsStr>,
{
self.env.push((a.as_ref().into(), b.as_ref().into()));
self
}
/// Run the compiler, generating the file `output`
///
/// This will return a result instead of panicing; see compile() for the complete description.
pub fn try_compile(&self, output: &str) -> Result<(), Error> {
let mut output_components = Path::new(output).components();
match (output_components.next(), output_components.next()) {
(Some(Component::Normal(_)), None) => {}
_ => {
return Err(Error::new(
ErrorKind::InvalidArgument,
"argument of `compile` must be a single normal path component",
));
}
}
let (lib_name, gnu_lib_name) = if output.starts_with("lib") && output.ends_with(".a") {
(&output[3..output.len() - 2], output.to_owned())
} else {
let mut gnu = String::with_capacity(5 + output.len());
gnu.push_str("lib");
gnu.push_str(&output);
gnu.push_str(".a");
(output, gnu)
};
let dst = self.get_out_dir()?;
let mut objects = Vec::new();
for file in self.files.iter() {
let obj = if file.has_root() || file.components().any(|x| x == Component::ParentDir) {
// If `file` is an absolute path or might not be usable directly as a suffix due to
// using "..", use the `basename` prefixed with the `dirname`'s hash to ensure name
// uniqueness.
let basename = file
.file_name()
.ok_or_else(|| Error::new(ErrorKind::InvalidArgument, "file_name() failure"))?
.to_string_lossy();
let dirname = file
.parent()
.ok_or_else(|| Error::new(ErrorKind::InvalidArgument, "parent() failure"))?
.to_string_lossy();
let mut hasher = hash_map::DefaultHasher::new();
hasher.write(dirname.to_string().as_bytes());
dst.join(format!("{:016x}-{}", hasher.finish(), basename))
.with_extension("o")
} else {
dst.join(file).with_extension("o")
};
let obj = if !obj.starts_with(&dst) {
dst.join(obj.file_name().ok_or_else(|| {
Error::new(ErrorKind::IOError, "Getting object file details failed.")
})?)
} else {
obj
};
match obj.parent() {
Some(s) => fs::create_dir_all(s)?,
None => {
return Err(Error::new(
ErrorKind::IOError,
"Getting object file details failed.",
));
}
};
objects.push(Object::new(file.to_path_buf(), obj));
}
let print = PrintThread::new()?;
self.compile_objects(&objects, &print)?;
self.assemble(lib_name, &dst.join(gnu_lib_name), &objects, &print)?;
if self.get_target()?.contains("msvc") {
let compiler = self.get_base_compiler()?;
let atlmfc_lib = compiler
.env()
.iter()
.find(|&&(ref var, _)| var.as_os_str() == OsStr::new("LIB"))
.and_then(|&(_, ref lib_paths)| {
env::split_paths(lib_paths).find(|path| {
let sub = Path::new("atlmfc/lib");
path.ends_with(sub) || path.parent().map_or(false, |p| p.ends_with(sub))
})
});
if let Some(atlmfc_lib) = atlmfc_lib {
self.print(&format_args!(
"cargo:rustc-link-search=native={}",
atlmfc_lib.display()
));
}
}
if self.link_lib_modifiers.is_empty() {
self.print(&format_args!("cargo:rustc-link-lib=static={}", lib_name));
} else {
let m = self.link_lib_modifiers.join(",");
self.print(&format_args!(
"cargo:rustc-link-lib=static:{}={}",
m, lib_name
));
}
self.print(&format_args!(
"cargo:rustc-link-search=native={}",
dst.display()
));
// Add specific C++ libraries, if enabled.
if self.cpp {
if let Some(stdlib) = self.get_cpp_link_stdlib()? {
self.print(&format_args!("cargo:rustc-link-lib={}", stdlib));
}
}
let cudart = match &self.cudart {
Some(opt) => &*opt, // {none|shared|static}
None => "none",
};
if cudart != "none" {
if let Some(nvcc) = which(&self.get_compiler().path, None) {
// Try to figure out the -L search path. If it fails,
// it's on user to specify one by passing it through
// RUSTFLAGS environment variable.
let mut libtst = false;
let mut libdir = nvcc;
libdir.pop(); // remove 'nvcc'
libdir.push("..");
let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
if cfg!(target_os = "linux") {
libdir.push("targets");
libdir.push(target_arch.to_owned() + "-linux");
libdir.push("lib");
libtst = true;
} else if cfg!(target_env = "msvc") {
libdir.push("lib");
match target_arch.as_str() {
"x86_64" => {
libdir.push("x64");
libtst = true;
}
"x86" => {
libdir.push("Win32");
libtst = true;
}
_ => libtst = false,
}
}
if libtst && libdir.is_dir() {
println!(
"cargo:rustc-link-search=native={}",
libdir.to_str().unwrap()
);
}
// And now the -l flag.
let lib = match cudart {
"shared" => "cudart",
"static" => "cudart_static",
bad => panic!("unsupported cudart option: {}", bad),
};
println!("cargo:rustc-link-lib={}", lib);
}
}
Ok(())
}
/// Run the compiler, generating the file `output`
///
/// # Library name
///
/// The `output` string argument determines the file name for the compiled
/// library. The Rust compiler will create an assembly named "lib"+output+".a".
/// MSVC will create a file named output+".lib".
///
/// The choice of `output` is close to arbitrary, but:
///
/// - must be nonempty,
/// - must not contain a path separator (`/`),
/// - must be unique across all `compile` invocations made by the same build
/// script.
///
/// If your build script compiles a single source file, the base name of
/// that source file would usually be reasonable:
///
/// ```no_run
/// cc::Build::new().file("blobstore.c").compile("blobstore");
/// ```
///
/// Compiling multiple source files, some people use their crate's name, or
/// their crate's name + "-cc".
///
/// Otherwise, please use your imagination.
///
/// For backwards compatibility, if `output` starts with "lib" *and* ends
/// with ".a", a second "lib" prefix and ".a" suffix do not get added on,
/// but this usage is deprecated; please omit `lib` and `.a` in the argument
/// that you pass.
///
/// # Panics
///
/// Panics if `output` is not formatted correctly or if one of the underlying
/// compiler commands fails. It can also panic if it fails reading file names
/// or creating directories.
pub fn compile(&self, output: &str) {
if let Err(e) = self.try_compile(output) {
fail(&e.message);
}
}
#[cfg(feature = "parallel")]
fn compile_objects(&self, objs: &[Object], print: &PrintThread) -> Result<(), Error> {
use std::sync::{mpsc, Once};
if objs.len() <= 1 {
for obj in objs {
let (mut cmd, name) = self.create_compile_object_cmd(obj)?;
run(&mut cmd, &name, print)?;
}
return Ok(());
}
// 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();
// Reacquire our process's token on drop
let _reacquire = server.release_raw().ok().map(|_| JobserverToken(server));
// 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 spawn the process to actually compile objects in
// parallel after we've acquired a token to perform some work
//
// 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 wait on all the processes and propagate the results of compilation.
let (tx, rx) = mpsc::channel::<(_, String, KillOnDrop, _)>();
// Since jobserver::Client::acquire can block, waiting
// must be done in parallel so that acquire won't block forever.
let wait_thread = thread::Builder::new().spawn(move || {
let mut error = None;
let mut pendings = Vec::new();
// Buffer the stdout
let mut stdout = io::BufWriter::with_capacity(128, io::stdout());
let mut backoff_cnt = 0;
loop {
let mut has_made_progress = false;
// Reading new pending tasks
loop {
match rx.try_recv() {
Ok(pending) => {
has_made_progress = true;
pendings.push(pending)
}
Err(mpsc::TryRecvError::Disconnected) if pendings.is_empty() => {
let _ = stdout.flush();
return if let Some(err) = error {
Err(err)
} else {
Ok(())
};
}
_ => break,
}
}
// Try waiting on them.
pendings.retain_mut(|(cmd, program, child, _)| {
match try_wait_on_child(cmd, program, &mut child.0, &mut stdout) {
Ok(Some(())) => {
// Task done, remove the entry
has_made_progress = true;
false
}
Ok(None) => true, // Task still not finished, keep the entry
Err(err) => {
// Task fail, remove the entry.
has_made_progress = true;
// Since we can only return one error, log the error to make
// sure users always see all the compilation failures.
let _ = writeln!(stdout, "cargo:warning={}", err);
error = Some(err);
false
}
}
});
if !has_made_progress {
if backoff_cnt > 3 {
// We have yielded at least three times without making'
// any progress, so we will sleep for a while.
let duration =
std::time::Duration::from_millis(100 * (backoff_cnt - 3).min(10));
thread::sleep(duration);
} else {
// Given that we spawned a lot of compilation tasks, it is unlikely
// that OS cannot find other ready task to execute.
//
// If all of them are done, then we will yield them and spawn more,
// or simply returns.
//
// Thus this will not be turned into a busy-wait loop and it will not
// waste CPU resource.
thread::yield_now();
}
}
backoff_cnt = if has_made_progress {
0
} else {
backoff_cnt + 1
};
}
})?;
for obj in objs {
let (mut cmd, program) = self.create_compile_object_cmd(obj)?;
let token = server.acquire()?;
let child = spawn(&mut cmd, &program, print.pipe_writer_cloned()?.unwrap())?;
tx.send((cmd, program, KillOnDrop(child), token))
.expect("Wait thread must be alive until all compilation jobs are done, otherwise we risk deadlock");
}
// Drop tx so that the wait_thread could return
drop(tx);
return wait_thread.join().expect("wait_thread panics");
/// 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 select something
// reasonable and crate a new jobserver. Use `NUM_JOBS` if set (it's
// configured by Cargo) and otherwise just fall back to a
// semi-reasonable number. Note that we could use `num_cpus` here
// but it's an extra dependency that will almost never be used, so
// it's generally not too worth it.
let mut parallelism = 4;
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 KillOnDrop(Child);
impl Drop for KillOnDrop {
fn drop(&mut self) {
let child = &mut self.0;
child.kill().ok();
}
}
struct JobserverToken(&'static jobserver::Client);
impl Drop for JobserverToken {
fn drop(&mut self) {
let _ = self.0.acquire_raw();
}
}
}
#[cfg(not(feature = "parallel"))]
fn compile_objects(&self, objs: &[Object], print: &PrintThread) -> Result<(), Error> {
for obj in objs {
let (mut cmd, name) = self.create_compile_object_cmd(obj)?;
run(&mut cmd, &name, print)?;
}
Ok(())
}
fn create_compile_object_cmd(&self, obj: &Object) -> Result<(Command, String), Error> {
let asm_ext = AsmFileExt::from_path(&obj.src);
let is_asm = asm_ext.is_some();
let target = self.get_target()?;
let msvc = target.contains("msvc");
let compiler = self.try_get_compiler()?;
let clang = compiler.family == ToolFamily::Clang;
let gnu = compiler.family == ToolFamily::Gnu;
let (mut cmd, name) = if msvc && asm_ext == Some(AsmFileExt::DotAsm) {
self.msvc_macro_assembler()?
} else {
let mut cmd = compiler.to_command();
for &(ref a, ref b) in self.env.iter() {
cmd.env(a, b);
}
(
cmd,
compiler
.path
.file_name()
.ok_or_else(|| Error::new(ErrorKind::IOError, "Failed to get compiler path."))?
.to_string_lossy()
.into_owned(),
)
};
let is_arm = target.contains("aarch64") || target.contains("arm");
command_add_output_file(
&mut cmd, &obj.dst, self.cuda, msvc, clang, gnu, is_asm, is_arm,
);
// armasm and armasm64 don't requrie -c option
if !msvc || !is_asm || !is_arm {
cmd.arg("-c");
}
if self.cuda && self.cuda_file_count() > 1 {
cmd.arg("--device-c");
}
if is_asm {
cmd.args(self.asm_flags.iter().map(std::ops::Deref::deref));
}
if compiler.family == (ToolFamily::Msvc { clang_cl: true }) && !is_asm {
// #513: For `clang-cl`, separate flags/options from the input file.
// When cross-compiling macOS -> Windows, this avoids interpreting
// common `/Users/...` paths as the `/U` flag and triggering
// `-Wslash-u-filename` warning.
cmd.arg("--");
}
cmd.arg(&obj.src);
if cfg!(target_os = "macos") {
self.fix_env_for_apple_os(&mut cmd)?;
}
Ok((cmd, name))
}
/// This will return a result instead of panicing; see expand() for the complete description.
pub fn try_expand(&self) -> Result<Vec<u8>, Error> {
let compiler = self.try_get_compiler()?;
let mut cmd = compiler.to_command();
for &(ref a, ref b) in self.env.iter() {
cmd.env(a, b);
}
cmd.arg("-E");
assert!(
self.files.len() <= 1,
"Expand may only be called for a single file"
);
cmd.args(self.files.iter().map(std::ops::Deref::deref));
let name = compiler
.path
.file_name()
.ok_or_else(|| Error::new(ErrorKind::IOError, "Failed to get compiler path."))?
.to_string_lossy()
.into_owned();
Ok(run_output(&mut cmd, &name)?)
}
/// Run the compiler, returning the macro-expanded version of the input files.
///
/// This is only relevant for C and C++ files.
///
/// # Panics
/// Panics if more than one file is present in the config, or if compiler
/// path has an invalid file name.
///
/// # Example
/// ```no_run
/// let out = cc::Build::new().file("src/foo.c").expand();
/// ```
pub fn expand(&self) -> Vec<u8> {
match self.try_expand() {
Err(e) => fail(&e.message),
Ok(v) => v,
}
}
/// Get the compiler that's in use for this configuration.
///
/// This function will return a `Tool` which represents the culmination
/// of this configuration at a snapshot in time. The returned compiler can
/// be inspected (e.g. the path, arguments, environment) to forward along to
/// other tools, or the `to_command` method can be used to invoke the
/// compiler itself.
///
/// This method will take into account all configuration such as debug
/// information, optimization level, include directories, defines, etc.
/// Additionally, the compiler binary in use follows the standard
/// conventions for this path, e.g. looking at the explicitly set compiler,
/// environment variables (a number of which are inspected here), and then
/// falling back to the default configuration.
///
/// # Panics
///
/// Panics if an error occurred while determining the architecture.
pub fn get_compiler(&self) -> Tool {
match self.try_get_compiler() {
Ok(tool) => tool,
Err(e) => fail(&e.message),
}
}
/// Get the compiler that's in use for this configuration.
///
/// This will return a result instead of panicing; see get_compiler() for the complete description.
pub fn try_get_compiler(&self) -> Result<Tool, Error> {
let opt_level = self.get_opt_level()?;
let target = self.get_target()?;
let mut cmd = self.get_base_compiler()?;
// 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 !no_defaults {
self.add_default_flags(&mut cmd, &target, &opt_level)?;
} else {
println!("Info: default compiler flags are disabled");
}
if let Some(ref std) = self.std {
let separator = match cmd.family {
ToolFamily::Msvc { .. } => ':',
ToolFamily::Gnu | ToolFamily::Clang => '=',
};
cmd.push_cc_arg(format!("-std{}{}", separator, std).into());
}
if let Ok(flags) = self.envflags(if self.cpp { "CXXFLAGS" } else { "CFLAGS" }) {
for arg in flags {
cmd.push_cc_arg(arg.into());
}
}
for directory in self.include_directories.iter() {
cmd.args.push("-I".into());
cmd.args.push((**directory).into());
}
// If warnings and/or extra_warnings haven't been explicitly set,
// then we set them only if the environment doesn't already have
// CFLAGS/CXXFLAGS, since those variables presumably already contain
// the desired set of warnings flags.
if self
.warnings
.unwrap_or(if self.has_flags() { false } else { true })
{
let wflags = cmd.family.warnings_flags().into();
cmd.push_cc_arg(wflags);
}
if self
.extra_warnings
.unwrap_or(if self.has_flags() { false } else { true })
{
if let Some(wflags) = cmd.family.extra_warnings_flags() {
cmd.push_cc_arg(wflags.into());
}
}
for flag in self.flags.iter() {
cmd.args.push((**flag).into());
}
for flag in self.flags_supported.iter() {
if self.is_flag_supported(flag).unwrap_or(false) {
cmd.push_cc_arg((**flag).into());
}
}
for &(ref key, ref value) in self.definitions.iter() {
if let Some(ref value) = *value {
cmd.args.push(format!("-D{}={}", key, value).into());
} else {
cmd.args.push(format!("-D{}", key).into());
}
}
if self.warnings_into_errors {
let warnings_to_errors_flag = cmd.family.warnings_to_errors_flag().into();
cmd.push_cc_arg(warnings_to_errors_flag);
}
Ok(cmd)
}
fn add_default_flags(
&self,
cmd: &mut Tool,
target: &str,
opt_level: &str,
) -> Result<(), Error> {
// Non-target flags
// If the flag is not conditioned on target variable, it belongs here :)
match cmd.family {
ToolFamily::Msvc { .. } => {
cmd.push_cc_arg("-nologo".into());
let crt_flag = match self.static_crt {
Some(true) => "-MT",
Some(false) => "-MD",
None => {
let features = self.getenv("CARGO_CFG_TARGET_FEATURE");
let features = features.as_deref().unwrap_or_default();
if features.contains("crt-static") {
"-MT"
} else {
"-MD"
}
}
};
cmd.push_cc_arg(crt_flag.into());
match &opt_level[..] {
// Msvc uses /O1 to enable all optimizations that minimize code size.
"z" | "s" | "1" => cmd.push_opt_unless_duplicate("-O1".into()),
// -O3 is a valid value for gcc and clang compilers, but not msvc. Cap to /O2.
"2" | "3" => cmd.push_opt_unless_duplicate("-O2".into()),
_ => {}
}
}
ToolFamily::Gnu | ToolFamily::Clang => {
// arm-linux-androideabi-gcc 4.8 shipped with Android NDK does
// not support '-Oz'
if opt_level == "z" && cmd.family != ToolFamily::Clang {
cmd.push_opt_unless_duplicate("-Os".into());
} else {
cmd.push_opt_unless_duplicate(format!("-O{}", opt_level).into());
}
if cmd.family == ToolFamily::Clang && target.contains("windows") {
// Disambiguate mingw and msvc on Windows. Problem is that
// depending on the origin clang can default to a mismatchig
// run-time.
cmd.push_cc_arg(format!("--target={}", target).into());
}
if cmd.family == ToolFamily::Clang && target.contains("android") {
// For compatibility with code that doesn't use pre-defined `__ANDROID__` macro.
// If compiler used via ndk-build or cmake (officially supported build methods)
// this macros is defined.
// See https://android.googlesource.com/platform/ndk/+/refs/heads/ndk-release-r21/build/cmake/android.toolchain.cmake#456
// https://android.googlesource.com/platform/ndk/+/refs/heads/ndk-release-r21/build/core/build-binary.mk#141
cmd.push_opt_unless_duplicate("-DANDROID".into());
}
if !target.contains("apple-ios") && !target.contains("apple-watchos") {
cmd.push_cc_arg("-ffunction-sections".into());
cmd.push_cc_arg("-fdata-sections".into());
}
// Disable generation of PIC on bare-metal for now: rust-lld doesn't support this yet
if self.pic.unwrap_or(
!target.contains("windows")
&& !target.contains("-none-")
&& !target.contains("uefi"),
) {
cmd.push_cc_arg("-fPIC".into());
// PLT only applies if code is compiled with PIC support,
// and only for ELF targets.
if target.contains("linux") && !self.use_plt.unwrap_or(true) {
cmd.push_cc_arg("-fno-plt".into());
}
}
}
}
if self.get_debug() {
if self.cuda {
// NVCC debug flag
cmd.args.push("-G".into());
}
let family = cmd.family;
family.add_debug_flags(cmd, self.get_dwarf_version());
}
if self.get_force_frame_pointer() {
let family = cmd.family;
family.add_force_frame_pointer(cmd);
}
// Target flags
match cmd.family {
ToolFamily::Clang => {
if !(target.contains("android")
&& android_clang_compiler_uses_target_arg_internally(&cmd.path))
{
if target.contains("darwin") {
if let Some(arch) =
map_darwin_target_from_rust_to_compiler_architecture(target)
{
cmd.args
.push(format!("--target={}-apple-darwin", arch).into());
}
} else if target.contains("macabi") {
if let Some(arch) =
map_darwin_target_from_rust_to_compiler_architecture(target)
{
cmd.args
.push(format!("--target={}-apple-ios-macabi", arch).into());
}
} else if target.contains("ios-sim") {
if let Some(arch) =
map_darwin_target_from_rust_to_compiler_architecture(target)
{
let deployment_target = env::var("IPHONEOS_DEPLOYMENT_TARGET")
.unwrap_or_else(|_| "7.0".into());
cmd.args.push(
format!(
"--target={}-apple-ios{}-simulator",
arch, deployment_target
)
.into(),
);
}
} else if target.contains("watchos-sim") {
if let Some(arch) =
map_darwin_target_from_rust_to_compiler_architecture(target)
{
let deployment_target = env::var("WATCHOS_DEPLOYMENT_TARGET")
.unwrap_or_else(|_| "5.0".into());
cmd.args.push(
format!(
"--target={}-apple-watchos{}-simulator",
arch, deployment_target
)
.into(),
);
}
} else if target.starts_with("riscv64gc-") {
cmd.args.push(
format!("--target={}", target.replace("riscv64gc", "riscv64")).into(),
);
} else if target.starts_with("riscv32gc-") {
cmd.args.push(
format!("--target={}", target.replace("riscv32gc", "riscv32")).into(),
);
} else if target.contains("uefi") {
if target.contains("x86_64") {
cmd.args.push("--target=x86_64-unknown-windows-gnu".into());
} else if target.contains("i686") {
cmd.args.push("--target=i686-unknown-windows-gnu".into())
} else if target.contains("aarch64") {
cmd.args.push("--target=aarch64-unknown-windows-gnu".into())
}
} else if target.ends_with("-freebsd") {
// FreeBSD only supports C++11 and above when compiling against libc++
// (available from FreeBSD 10 onwards). Under FreeBSD, clang uses libc++ by
// default on FreeBSD 10 and newer unless `--target` is manually passed to
// the compiler, in which case its default behavior differs:
// * If --target=xxx-unknown-freebsdX(.Y) is specified and X is greater than
// or equal to 10, clang++ uses libc++
// * If --target=xxx-unknown-freebsd is specified (without a version),
// clang++ cannot assume libc++ is available and reverts to a default of
// libstdc++ (this behavior was changed in llvm 14).
//
// This breaks C++11 (or greater) builds if targeting FreeBSD with the
// generic xxx-unknown-freebsd triple on clang 13 or below *without*
// explicitly specifying that libc++ should be used.
// When cross-compiling, we can't infer from the rust/cargo target triple
// which major version of FreeBSD we are targeting, so we need to make sure
// that libc++ is used (unless the user has explicitly specified otherwise).
// There's no compelling reason to use a different approach when compiling
// natively.
if self.cpp && self.cpp_set_stdlib.is_none() {
cmd.push_cc_arg("-stdlib=libc++".into());
}
cmd.push_cc_arg(format!("--target={}", target).into());
} else {
cmd.push_cc_arg(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.push_cc_arg("-Brepro".into());
if clang_cl {
if target.contains("x86_64") {
cmd.push_cc_arg("-m64".into());
} else if target.contains("86") {
cmd.push_cc_arg("-m32".into());
cmd.push_cc_arg("-arch:IA32".into());
} else {
cmd.push_cc_arg(format!("--target={}", target).into());
}
} else {
if target.contains("i586") {
cmd.push_cc_arg("-arch:IA32".into());
}
}
// There is a check in corecrt.h that will generate a
// compilation error if
// _ARM_WINAPI_PARTITION_DESKTOP_SDK_AVAILABLE is
// not defined to 1. The check was added in Windows
// 8 days because only store apps were allowed on ARM.
// This changed with the release of Windows 10 IoT Core.
// The check will be going away in future versions of
// the SDK, but for all released versions of the
// Windows SDK it is required.
if target.contains("arm") || target.contains("thumb") {
cmd.args
.push("-D_ARM_WINAPI_PARTITION_DESKTOP_SDK_AVAILABLE=1".into());
}
}
ToolFamily::Gnu => {
if target.contains("i686") || target.contains("i586") {
cmd.args.push("-m32".into());
} else if target == "x86_64-unknown-linux-gnux32" {
cmd.args.push("-mx32".into());
} else if target.contains("x86_64") || target.contains("powerpc64") {
cmd.args.push("-m64".into());
}
if target.contains("darwin") {
if let Some(arch) = map_darwin_target_from_rust_to_compiler_architecture(target)
{
cmd.args.push("-arch".into());
cmd.args.push(arch.into());
}
}
if target.contains("-kmc-solid_") {
cmd.args.push("-finput-charset=utf-8".into());
}
if self.static_flag.is_none() {
let features = self.getenv("CARGO_CFG_TARGET_FEATURE");
let features = features.as_deref().unwrap_or_default();
if features.contains("crt-static") {
cmd.args.push("-static".into());
}
}
// armv7 targets get to use armv7 instructions
if (target.starts_with("armv7") || target.starts_with("thumbv7"))
&& (target.contains("-linux-") || target.contains("-kmc-solid_"))
{
cmd.args.push("-march=armv7-a".into());
if target.ends_with("eabihf") {
// lowest common denominator FPU
cmd.args.push("-mfpu=vfpv3-d16".into());
}
}
// (x86 Android doesn't say "eabi")
if target.contains("-androideabi") && target.contains("v7") {
// -march=armv7-a handled above
cmd.args.push("-mthumb".into());
if !target.contains("neon") {
// On android we can guarantee some extra float instructions
// (specified in the android spec online)
// NEON guarantees even more; see below.
cmd.args.push("-mfpu=vfpv3-d16".into());
}
cmd.args.push("-mfloat-abi=softfp".into());
}
if target.contains("neon") {
cmd.args.push("-mfpu=neon-vfpv4".into());
}
if target.starts_with("armv4t-unknown-linux-") {
cmd.args.push("-march=armv4t".into());
cmd.args.push("-marm".into());
cmd.args.push("-mfloat-abi=soft".into());
}
if target.starts_with("armv5te-unknown-linux-") {
cmd.args.push("-march=armv5te".into());
cmd.args.push("-marm".into());
cmd.args.push("-mfloat-abi=soft".into());
}
// For us arm == armv6 by default
if target.starts_with("arm-unknown-linux-") {
cmd.args.push("-march=armv6".into());
cmd.args.push("-marm".into());
if target.ends_with("hf") {
cmd.args.push("-mfpu=vfp".into());
} else {
cmd.args.push("-mfloat-abi=soft".into());
}
}
// We can guarantee some settings for FRC
if target.starts_with("arm-frc-") {
cmd.args.push("-march=armv7-a".into());
cmd.args.push("-mcpu=cortex-a9".into());
cmd.args.push("-mfpu=vfpv3".into());
cmd.args.push("-mfloat-abi=softfp".into());
cmd.args.push("-marm".into());
}
// Turn codegen down on i586 to avoid some instructions.
if target.starts_with("i586-unknown-linux-") {
cmd.args.push("-march=pentium".into());
}
// Set codegen level for i686 correctly
if target.starts_with("i686-unknown-linux-") {
cmd.args.push("-march=i686".into());
}
// Looks like `musl-gcc` makes it hard for `-m32` to make its way
// all the way to the linker, so we need to actually instruct the
// linker that we're generating 32-bit executables as well. This'll
// typically only be used for build scripts which transitively use
// these flags that try to compile executables.
if target == "i686-unknown-linux-musl" || target == "i586-unknown-linux-musl" {
cmd.args.push("-Wl,-melf_i386".into());
}
if target.starts_with("thumb") {
cmd.args.push("-mthumb".into());
if target.ends_with("eabihf") {
cmd.args.push("-mfloat-abi=hard".into())
}
}
if target.starts_with("thumbv6m") {
cmd.args.push("-march=armv6s-m".into());
}
if target.starts_with("thumbv7em") {
cmd.args.push("-march=armv7e-m".into());
if target.ends_with("eabihf") {
cmd.args.push("-mfpu=fpv4-sp-d16".into())
}
}
if target.starts_with("thumbv7m") {
cmd.args.push("-march=armv7-m".into());
}
if target.starts_with("thumbv8m.base") {
cmd.args.push("-march=armv8-m.base".into());
}
if target.starts_with("thumbv8m.main") {
cmd.args.push("-march=armv8-m.main".into());
if target.ends_with("eabihf") {
cmd.args.push("-mfpu=fpv5-sp-d16".into())
}
}
if target.starts_with("armebv7r") | target.starts_with("armv7r") {
if target.starts_with("armeb") {
cmd.args.push("-mbig-endian".into());
} else {
cmd.args.push("-mlittle-endian".into());
}
// ARM mode
cmd.args.push("-marm".into());
// R Profile
cmd.args.push("-march=armv7-r".into());
if target.ends_with("eabihf") {
// Calling convention
cmd.args.push("-mfloat-abi=hard".into());
// lowest common denominator FPU
// (see Cortex-R4 technical reference manual)
cmd.args.push("-mfpu=vfpv3-d16".into())
} else {
// Calling convention
cmd.args.push("-mfloat-abi=soft".into());
}
}
if target.starts_with("armv7a") {
cmd.args.push("-march=armv7-a".into());
if target.ends_with("eabihf") {
// lowest common denominator FPU
cmd.args.push("-mfpu=vfpv3-d16".into());
}
}
if target.starts_with("riscv32") || target.starts_with("riscv64") {
// get the 32i/32imac/32imc/64gc/64imac/... part
let mut parts = target.split('-');
if let Some(arch) = parts.next() {
let arch = &arch[5..];
if target.contains("linux") && arch.starts_with("64") {
cmd.args.push(("-march=rv64gc").into());
cmd.args.push("-mabi=lp64d".into());
} else if target.contains("freebsd") && arch.starts_with("64") {
cmd.args.push(("-march=rv64gc").into());
cmd.args.push("-mabi=lp64d".into());
} else if target.contains("netbsd") && arch.starts_with("64") {
cmd.args.push(("-march=rv64gc").into());
cmd.args.push("-mabi=lp64d".into());
} else if target.contains("openbsd") && arch.starts_with("64") {
cmd.args.push(("-march=rv64gc").into());
cmd.args.push("-mabi=lp64d".into());
} else if target.contains("linux") && arch.starts_with("32") {
cmd.args.push(("-march=rv32gc").into());
cmd.args.push("-mabi=ilp32d".into());
} else if arch.starts_with("64") {
cmd.args.push(("-march=rv".to_owned() + arch).into());
cmd.args.push("-mabi=lp64".into());
} else {
cmd.args.push(("-march=rv".to_owned() + arch).into());
cmd.args.push("-mabi=ilp32".into());
}
cmd.args.push("-mcmodel=medany".into());
}
}
}
}
if target.contains("apple-ios") || target.contains("apple-watchos") {
self.ios_watchos_flags(cmd)?;
}
if self.static_flag.unwrap_or(false) {
cmd.args.push("-static".into());
}
if self.shared_flag.unwrap_or(false) {
cmd.args.push("-shared".into());
}
if self.cpp {
match (self.cpp_set_stdlib.as_ref(), cmd.family) {
(None, _) => {}
(Some(stdlib), ToolFamily::Gnu) | (Some(stdlib), ToolFamily::Clang) => {
cmd.push_cc_arg(format!("-stdlib=lib{}", stdlib).into());
}
_ => {
println!(
"cargo:warning=cpp_set_stdlib is specified, but the {:?} compiler \
does not support this option, ignored",
cmd.family
);
}
}
}
Ok(())
}
fn has_flags(&self) -> bool {
let flags_env_var_name = if self.cpp { "CXXFLAGS" } else { "CFLAGS" };
let flags_env_var_value = self.getenv_with_target_prefixes(flags_env_var_name);
if let Ok(_) = flags_env_var_value {
true
} else {
false
}
}
fn msvc_macro_assembler(&self) -> Result<(Command, String), Error> {
let target = self.get_target()?;
let tool = if target.contains("x86_64") {
"ml64.exe"
} else if target.contains("arm") {
"armasm.exe"
} else if target.contains("aarch64") {
"armasm64.exe"
} else {
"ml.exe"
};
let mut cmd = windows_registry::find(&target, tool).unwrap_or_else(|| self.cmd(tool));
cmd.arg("-nologo"); // undocumented, yet working with armasm[64]
for directory in self.include_directories.iter() {
cmd.arg("-I").arg(&**directory);
}
if target.contains("aarch64") || target.contains("arm") {
if self.get_debug() {
cmd.arg("-g");
}
println!("cargo:warning=The MSVC ARM assemblers do not support -D flags");
} else {
if self.get_debug() {
cmd.arg("-Zi");
}
for &(ref key, ref value) in self.definitions.iter() {
if let Some(ref value) = *value {
cmd.arg(&format!("-D{}={}", key, value));
} else {
cmd.arg(&format!("-D{}", key));
}
}
}
if target.contains("i686") || target.contains("i586") {
cmd.arg("-safeseh");
}
for flag in self.flags.iter() {
cmd.arg(&**flag);
}
Ok((cmd, tool.to_string()))
}
fn assemble(
&self,
lib_name: &str,
dst: &Path,
objs: &[Object],
print: &PrintThread,
) -> Result<(), Error> {
// Delete the destination if it exists as we want to
// create on the first iteration instead of appending.
let _ = fs::remove_file(dst);
// Add objects to the archive in limited-length batches. This helps keep
// the length of the command line within a reasonable length to avoid
// blowing system limits on limiting platforms like Windows.
let objs: Vec<_> = objs
.iter()
.map(|o| o.dst.as_path())
.chain(self.objects.iter().map(std::ops::Deref::deref))
.collect();
for chunk in objs.chunks(100) {
self.assemble_progressive(dst, chunk, print)?;
}
if self.cuda && self.cuda_file_count() > 0 {
// Link the device-side code and add it to the target library,
// so that non-CUDA linker can link the final binary.
let out_dir = self.get_out_dir()?;
let dlink = out_dir.join(lib_name.to_owned() + "_dlink.o");
let mut nvcc = self.get_compiler().to_command();
nvcc.arg("--device-link").arg("-o").arg(&dlink).arg(dst);
run(&mut nvcc, "nvcc", print)?;
self.assemble_progressive(dst, &[dlink.as_path()], print)?;
}
let target = self.get_target()?;
if target.contains("msvc") {
// The Rust compiler will look for libfoo.a and foo.lib, but the
// MSVC linker will also be passed foo.lib, so be sure that both
// exist for now.
let lib_dst = dst.with_file_name(format!("{}.lib", lib_name));
let _ = fs::remove_file(&lib_dst);
match fs::hard_link(&dst, &lib_dst).or_else(|_| {
// if hard-link fails, just copy (ignoring the number of bytes written)
fs::copy(&dst, &lib_dst).map(|_| ())
}) {
Ok(_) => (),
Err(_) => {
return Err(Error::new(
ErrorKind::IOError,
"Could not copy or create a hard-link to the generated lib file.",
));
}
};
} else {
// Non-msvc targets (those using `ar`) need a separate step to add
// the symbol table to archives since our construction command of
// `cq` doesn't add it for us.
let (mut ar, cmd, _any_flags) = self.get_ar()?;
// NOTE: We add `s` even if flags were passed using $ARFLAGS/ar_flag, because `s`
// here represents a _mode_, not an arbitrary flag. Further discussion of this choice
// can be seen in https://github.com/rust-lang/cc-rs/pull/763.
run(ar.arg("s").arg(dst), &cmd, print)?;
}
Ok(())
}
fn assemble_progressive(
&self,
dst: &Path,
objs: &[&Path],
print: &PrintThread,
) -> Result<(), Error> {
let target = self.get_target()?;
if target.contains("msvc") {
let (mut cmd, program, any_flags) = self.get_ar()?;
// NOTE: -out: here is an I/O flag, and so must be included even if $ARFLAGS/ar_flag is
// in use. -nologo on the other hand is just a regular flag, and one that we'll skip if
// the caller has explicitly dictated the flags they want. See
// https://github.com/rust-lang/cc-rs/pull/763 for further discussion.
let mut out = OsString::from("-out:");
out.push(dst);
cmd.arg(out);
if !any_flags {
cmd.arg("-nologo");
}
// If the library file already exists, add the library name
// as an argument to let lib.exe know we are appending the objs.
if dst.exists() {
cmd.arg(dst);
}
cmd.args(objs);
run(&mut cmd, &program, print)?;
} else {
let (mut ar, cmd, _any_flags) = 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");
// NOTE: We add cq here regardless of whether $ARFLAGS/ar_flag have been used because
// it dictates the _mode_ ar runs in, which the setter of $ARFLAGS/ar_flag can't
// dictate. See https://github.com/rust-lang/cc-rs/pull/763 for further discussion.
run(ar.arg("cq").arg(dst).args(objs), &cmd, print)?;
}
Ok(())
}
fn ios_watchos_flags(&self, cmd: &mut Tool) -> Result<(), Error> {
enum ArchSpec {
Device(&'static str),
Simulator(&'static str),
Catalyst(&'static str),
}
enum Os {
Ios,
WatchOs,
}
impl Display for Os {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
match self {
Os::Ios => f.write_str("iOS"),
Os::WatchOs => f.write_str("WatchOS"),
}
}
}
let target = self.get_target()?;
let os = if target.contains("-watchos") {
Os::WatchOs
} else {
Os::Ios
};
let arch = target.split('-').nth(0).ok_or_else(|| {
Error::new(
ErrorKind::ArchitectureInvalid,
format!("Unknown architecture for {} target.", os),
)
})?;
let is_catalyst = match target.split('-').nth(3) {
Some(v) => v == "macabi",
None => false,
};
let is_sim = match target.split('-').nth(3) {
Some(v) => v == "sim",
None => false,
};
let arch = if is_catalyst {
match arch {
"arm64e" => ArchSpec::Catalyst("arm64e"),
"arm64" | "aarch64" => ArchSpec::Catalyst("arm64"),
"x86_64" => ArchSpec::Catalyst("-m64"),
_ => {
return Err(Error::new(
ErrorKind::ArchitectureInvalid,
"Unknown architecture for iOS target.",
));
}
}
} else if is_sim {
match arch {
"arm64" | "aarch64" => ArchSpec::Simulator("arm64"),
"x86_64" => ArchSpec::Simulator("-m64"),
_ => {
return Err(Error::new(
ErrorKind::ArchitectureInvalid,
"Unknown architecture for iOS simulator target.",
));
}
}
} else {
match arch {
"arm" | "armv7" | "thumbv7" => ArchSpec::Device("armv7"),
"armv7k" => ArchSpec::Device("armv7k"),
"armv7s" | "thumbv7s" => ArchSpec::Device("armv7s"),
"arm64e" => ArchSpec::Device("arm64e"),
"arm64" | "aarch64" => ArchSpec::Device("arm64"),
"arm64_32" => ArchSpec::Device("arm64_32"),
"i386" | "i686" => ArchSpec::Simulator("-m32"),
"x86_64" => ArchSpec::Simulator("-m64"),
_ => {
return Err(Error::new(
ErrorKind::ArchitectureInvalid,
format!("Unknown architecture for {} target.", os),
));
}
}
};
let (sdk_prefix, sim_prefix, min_version) = match os {
Os::Ios => (
"iphone",
"ios-",
std::env::var("IPHONEOS_DEPLOYMENT_TARGET").unwrap_or_else(|_| "7.0".into()),
),
Os::WatchOs => (
"watch",
"watch",
std::env::var("WATCHOS_DEPLOYMENT_TARGET").unwrap_or_else(|_| "2.0".into()),
),
};
let sdk = match arch {
ArchSpec::Device(arch) => {
cmd.args.push("-arch".into());
cmd.args.push(arch.into());
cmd.args
.push(format!("-m{}os-version-min={}", sdk_prefix, min_version).into());
format!("{}os", sdk_prefix)
}
ArchSpec::Simulator(arch) => {
if arch.starts_with('-') {
// -m32 or -m64
cmd.args.push(arch.into());
} else {
cmd.args.push("-arch".into());
cmd.args.push(arch.into());
}
cmd.args
.push(format!("-m{}simulator-version-min={}", sim_prefix, min_version).into());
format!("{}simulator", sdk_prefix)
}
ArchSpec::Catalyst(_) => "macosx".to_owned(),
};
self.print(&format_args!("Detecting {} SDK path for {}", os, sdk));
let sdk_path = if let Some(sdkroot) = env::var_os("SDKROOT") {
sdkroot
} else {
self.apple_sdk_root(sdk.as_str())?
};
cmd.args.push("-isysroot".into());
cmd.args.push(sdk_path);
// TODO: Remove this once Apple stops accepting apps built with Xcode 13
cmd.args.push("-fembed-bitcode".into());
Ok(())
}
fn cmd<P: AsRef<OsStr>>(&self, prog: P) -> Command {
let mut cmd = Command::new(prog);
for &(ref a, ref b) in self.env.iter() {
cmd.env(a, b);
}
cmd
}
fn get_base_compiler(&self) -> Result<Tool, Error> {
if let Some(c) = &self.compiler {
return Ok(Tool::new((**c).to_owned()));
}
let host = self.get_host()?;
let target = self.get_target()?;
let target = &*target;
let (env, msvc, gnu, traditional, clang) = if self.cpp {
("CXX", "cl.exe", "g++", "c++", "clang++")
} else {
("CC", "cl.exe", "gcc", "cc", "clang")
};
// On historical Solaris systems, "cc" may have been Sun Studio, which
// is not flag-compatible with "gcc". This history casts a long shadow,
// and many modern illumos distributions today ship GCC as "gcc" without
// also making it available as "cc".
let default = if host.contains("solaris") || host.contains("illumos") {
gnu
} else {
traditional
};
let cl_exe = windows_registry::find_tool(&target, "cl.exe");
let tool_opt: Option<Tool> = self
.env_tool(env)
.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::with_clang_driver(tool, driver_mode);
if let Some(cc_wrapper) = wrapper {
t.cc_wrapper_path = Some(PathBuf::from(cc_wrapper));
}
for arg in args {
t.cc_wrapper_args.push(arg.into());
}
t
})
.or_else(|| {
if target.contains("emscripten") {
let tool = if self.cpp { "em++" } else { "emcc" };
// Windows uses bat file so we have to be a bit more specific
if cfg!(windows) {
let mut t = Tool::new(PathBuf::from("cmd"));
t.args.push("/c".into());
t.args.push(format!("{}.bat", tool).into());
Some(t)
} else {
Some(Tool::new(PathBuf::from(tool)))
}
} else {
None
}
})
.or_else(|| cl_exe.clone());
let tool = match tool_opt {
Some(t) => t,
None => {
let compiler = if host.contains("windows") && target.contains("windows") {
if target.contains("msvc") {
msvc.to_string()
} else {
let cc = if target.contains("llvm") { clang } else { gnu };
format!("{}.exe", cc)
}
} else if target.contains("apple-ios") {
clang.to_string()
} else if target.contains("apple-watchos") {
clang.to_string()
} else if target.contains("android") {
autodetect_android_compiler(&target, &host, gnu, clang)
} else if target.contains("cloudabi") {
format!("{}-{}", target, traditional)
} else if target == "wasm32-wasi"
|| target == "wasm32-unknown-wasi"
|| target == "wasm32-unknown-unknown"
{
"clang".to_string()
} else if target.contains("vxworks") {
if self.cpp {
"wr-c++".to_string()
} else {
"wr-cc".to_string()
}
} else if target.starts_with("armv7a-kmc-solid_") {
format!("arm-kmc-eabi-{}", gnu)
} else if target.starts_with("aarch64-kmc-solid_") {
format!("aarch64-kmc-elf-{}", gnu)
} else if &*self.get_host()? != target {
let prefix = self.prefix_for_target(&target);
match prefix {
Some(prefix) => {
let cc = if target.contains("llvm") { clang } else { gnu };
format!("{}-{}", prefix, cc)
}
None => default.to_string(),
}
} else {
default.to_string()
};
let mut t = Tool::new(PathBuf::from(compiler));
if let Some(cc_wrapper) = Self::rustc_wrapper_fallback() {
t.cc_wrapper_path = Some(PathBuf::from(cc_wrapper));
}
t
}
};
let mut tool = if self.cuda {
assert!(
tool.args.is_empty(),
"CUDA compilation currently assumes empty pre-existing args"
);
let nvcc = match self.getenv_with_target_prefixes("NVCC") {
Err(_) => PathBuf::from("nvcc"),
Ok(nvcc) => PathBuf::from(&*nvcc),
};
let mut nvcc_tool = Tool::with_features(nvcc, None, self.cuda);
nvcc_tool
.args
.push(format!("-ccbin={}", tool.path.display()).into());
nvcc_tool.family = tool.family;
nvcc_tool
} else {
tool
};
// New "standalone" C/C++ cross-compiler executables from recent Android NDK
// are just shell scripts that call main clang binary (from Android NDK) with
// proper `--target` argument.
//
// For example, armv7a-linux-androideabi16-clang passes
// `--target=armv7a-linux-androideabi16` to clang.
//
// As the shell script calls the main clang binary, the command line limit length
// on Windows is restricted to around 8k characters instead of around 32k characters.
// To remove this limit, we call the main clang binary directly and construct the
// `--target=` ourselves.
if host.contains("windows") && android_clang_compiler_uses_target_arg_internally(&tool.path)
{
if let Some(path) = tool.path.file_name() {
let file_name = path.to_str().unwrap().to_owned();
let (target, clang) = file_name.split_at(file_name.rfind("-").unwrap());
tool.path.set_file_name(clang.trim_start_matches("-"));
tool.path.set_extension("exe");
tool.args.push(format!("--target={}", target).into());
// Additionally, shell scripts for target i686-linux-android versions 16 to 24
// pass the `mstackrealign` option so we do that here as well.
if target.contains("i686-linux-android") {
let (_, version) = target.split_at(target.rfind("d").unwrap() + 1);
if let Ok(version) = version.parse::<u32>() {
if version > 15 && version < 25 {
tool.args.push("-mstackrealign".into());
}
}
}
};
}
// If we found `cl.exe` in our environment, the tool we're returning is
// an MSVC-like tool, *and* no env vars were set then set env vars for
// the tool that we're returning.
//
// Env vars are needed for things like `link.exe` being put into PATH as
// well as header include paths sometimes. These paths are automatically
// included by default but if the `CC` or `CXX` env vars are set these
// won't be used. This'll ensure that when the env vars are used to
// configure for invocations like `clang-cl` we still get a "works out
// of the box" experience.
if let Some(cl_exe) = cl_exe {
if tool.family == (ToolFamily::Msvc { clang_cl: true })
&& tool.env.len() == 0
&& target.contains("msvc")
{
for &(ref k, ref v) in cl_exe.env.iter() {
tool.env.push((k.to_owned(), v.to_owned()));
}
}
}
if target.contains("msvc") && tool.family == ToolFamily::Gnu {
println!("cargo:warning=GNU compiler is not supported for this target");
}
Ok(tool)
}
/// Returns a fallback `cc_compiler_wrapper` by introspecting `RUSTC_WRAPPER`
fn rustc_wrapper_fallback() -> Option<String> {
// No explicit CC wrapper was detected, but check if RUSTC_WRAPPER
// is defined and is a build accelerator that is compatible with
// C/C++ compilers (e.g. sccache)
const VALID_WRAPPERS: &[&'static str] = &["sccache", "cachepot"];
let rustc_wrapper = std::env::var_os("RUSTC_WRAPPER")?;
let wrapper_path = Path::new(&rustc_wrapper);
let wrapper_stem = wrapper_path.file_stem()?;
if VALID_WRAPPERS.contains(&wrapper_stem.to_str()?) {
Some(rustc_wrapper.to_str()?.to_owned())
} else {
None
}
}
/// Returns compiler path, optional modifier name from whitelist, and arguments vec
fn env_tool(&self, name: &str) -> Option<(PathBuf, Option<String>, Vec<String>)> {
let tool = match self.getenv_with_target_prefixes(name) {
Ok(tool) => tool,
Err(_) => return None,
};
// If this is an exact path on the filesystem we don't want to do any
// interpretation at all, just pass it on through. This'll hopefully get
// us to support spaces-in-paths.
if Path::new(&*tool).exists() {
return Some((PathBuf::from(&*tool), None, Vec::new()));
}
// Ok now we want to handle a couple of scenarios. We'll assume from
// here on out that spaces are splitting separate arguments. Two major
// features we want to support are:
//
// CC='sccache cc'
//
// aka using `sccache` or any other wrapper/caching-like-thing for
// compilations. We want to know what the actual compiler is still,
// though, because our `Tool` API support introspection of it to see
// what compiler is in use.
//
// additionally we want to support
//
// CC='cc -flag'
//
// where the CC env var is used to also pass default flags to the C
// compiler.
//
// It's true that everything here is a bit of a pain, but apparently if
// you're not literally make or bash then you get a lot of bug reports.
let known_wrappers = ["ccache", "distcc", "sccache", "icecc", "cachepot"];
let mut parts = tool.split_whitespace();
let maybe_wrapper = match parts.next() {
Some(s) => s,
None => return None,
};
let file_stem = Path::new(maybe_wrapper)
.file_stem()
.unwrap()
.to_str()
.unwrap();
if known_wrappers.contains(&file_stem) {
if let Some(compiler) = parts.next() {
return Some((
compiler.into(),
Some(maybe_wrapper.to_string()),
parts.map(|s| s.to_string()).collect(),
));
}
}
Some((
maybe_wrapper.into(),
Self::rustc_wrapper_fallback(),
parts.map(|s| s.to_string()).collect(),
))
}
/// Returns the C++ standard library:
/// 1. If [cpp_link_stdlib](cc::Build::cpp_link_stdlib) is set, uses its value.
/// 2. Else if the `CXXSTDLIB` environment variable is set, uses its value.
/// 3. Else the default is `libc++` for OS X and BSDs, `libc++_shared` for Android,
/// `None` for MSVC and `libstdc++` for anything else.
fn get_cpp_link_stdlib(&self) -> Result<Option<String>, Error> {
match &self.cpp_link_stdlib {
Some(s) => Ok(s.as_ref().map(|s| (*s).to_string())),
None => {
if let Ok(stdlib) = self.getenv_with_target_prefixes("CXXSTDLIB") {
if stdlib.is_empty() {
Ok(None)
} else {
Ok(Some(stdlib.to_string()))
}
} else {
let target = self.get_target()?;
if target.contains("msvc") {
Ok(None)
} else if target.contains("apple") {
Ok(Some("c++".to_string()))
} else if target.contains("freebsd") {
Ok(Some("c++".to_string()))
} else if target.contains("openbsd") {
Ok(Some("c++".to_string()))
} else if target.contains("aix") {
Ok(Some("c++".to_string()))
} else if target.contains("android") {
Ok(Some("c++_shared".to_string()))
} else {
Ok(Some("stdc++".to_string()))
}
}
}
}
}
fn get_ar(&self) -> Result<(Command, String, bool), Error> {
self.try_get_archiver_and_flags()
}
/// Get the archiver (ar) that's in use for this configuration.
///
/// You can use [`Command::get_program`] to get just the path to the command.
///
/// This method will take into account all configuration such as debug
/// information, optimization level, include directories, defines, etc.
/// Additionally, the compiler binary in use follows the standard
/// conventions for this path, e.g. looking at the explicitly set compiler,
/// environment variables (a number of which are inspected here), and then
/// falling back to the default configuration.
///
/// # Panics
///
/// Panics if an error occurred while determining the architecture.
pub fn get_archiver(&self) -> Command {
match self.try_get_archiver() {
Ok(tool) => tool,
Err(e) => fail(&e.message),
}
}
/// Get the archiver that's in use for this configuration.
///
/// This will return a result instead of panicing;
/// see [`get_archiver()`] for the complete description.
pub fn try_get_archiver(&self) -> Result<Command, Error> {
Ok(self.try_get_archiver_and_flags()?.0)
}
fn try_get_archiver_and_flags(&self) -> Result<(Command, String, bool), Error> {
let (mut cmd, name) = self.get_base_archiver()?;
let mut any_flags = false;
if let Ok(flags) = self.envflags("ARFLAGS") {
any_flags = any_flags | !flags.is_empty();
cmd.args(flags);
}
for flag in &self.ar_flags {
any_flags = true;
cmd.arg(&**flag);
}
Ok((cmd, name, any_flags))
}
fn get_base_archiver(&self) -> Result<(Command, String), Error> {
if let Some(ref a) = self.archiver {
return Ok((self.cmd(&**a), a.to_string_lossy().into_owned()));
}
self.get_base_archiver_variant("AR", "ar")
}
/// Get the ranlib that's in use for this configuration.
///
/// You can use [`Command::get_program`] to get just the path to the command.
///
/// This method will take into account all configuration such as debug
/// information, optimization level, include directories, defines, etc.
/// Additionally, the compiler binary in use follows the standard
/// conventions for this path, e.g. looking at the explicitly set compiler,
/// environment variables (a number of which are inspected here), and then
/// falling back to the default configuration.
///
/// # Panics
///
/// Panics if an error occurred while determining the architecture.
pub fn get_ranlib(&self) -> Command {
match self.try_get_ranlib() {
Ok(tool) => tool,
Err(e) => fail(&e.message),
}
}
/// Get the ranlib that's in use for this configuration.
///
/// This will return a result instead of panicing;
/// see [`get_ranlib()`] for the complete description.
pub fn try_get_ranlib(&self) -> Result<Command, Error> {
let mut cmd = self.get_base_ranlib()?;
if let Ok(flags) = self.envflags("RANLIBFLAGS") {
cmd.args(flags);
}
Ok(cmd)
}
fn get_base_ranlib(&self) -> Result<Command, Error> {
if let Some(ref r) = self.ranlib {
return Ok(self.cmd(&**r));
}
Ok(self.get_base_archiver_variant("RANLIB", "ranlib")?.0)
}
fn get_base_archiver_variant(&self, env: &str, tool: &str) -> Result<(Command, String), Error> {
let target = self.get_target()?;
let mut name = String::new();
let tool_opt: Option<Command> = self
.env_tool(env)
.map(|(tool, _wrapper, args)| {
let mut cmd = self.cmd(tool);
cmd.args(args);
cmd
})
.or_else(|| {
if target.contains("emscripten") {
// Windows use bat files so we have to be a bit more specific
if cfg!(windows) {
let mut cmd = self.cmd("cmd");
name = format!("em{}.bat", tool);
cmd.arg("/c").arg(&name);
Some(cmd)
} else {
name = format!("em{}", tool);
Some(self.cmd(&name))
}
} else if target.starts_with("wasm32") {
// Formally speaking one should be able to use this approach,
// parsing -print-search-dirs output, to cover all clang targets,
// including Android SDKs and other cross-compilation scenarios...
// And even extend it to gcc targets by seaching for "ar" instead
// of "llvm-ar"...
let compiler = self.get_base_compiler().ok()?;
if compiler.family == ToolFamily::Clang {
name = format!("llvm-{}", tool);
search_programs(&mut self.cmd(&compiler.path), &name)
.map(|name| self.cmd(&name))
} else {
None
}
} else {
None
}
});
let default = tool.to_string();
let tool = match tool_opt {
Some(t) => t,
None => {
if target.contains("android") {
name = format!("{}-{}", target.replace("armv7", "arm"), tool);
self.cmd(&name)
} else if target.contains("msvc") {
// NOTE: There isn't really a ranlib on msvc, so arguably we should return
// `None` somehow here. But in general, callers will already have to be aware
// of not running ranlib on Windows anyway, so it feels okay to return lib.exe
// here.
let compiler = self.get_base_compiler()?;
let mut lib = String::new();
if compiler.family == (ToolFamily::Msvc { clang_cl: true }) {
// See if there is 'llvm-lib' next to 'clang-cl'
// Another possibility could be to see if there is 'clang'
// next to 'clang-cl' and use 'search_programs()' to locate
// 'llvm-lib'. This is because 'clang-cl' doesn't support
// the -print-search-dirs option.
if let Some(mut cmd) = which(&compiler.path, None) {
cmd.pop();
cmd.push("llvm-lib.exe");
if let Some(llvm_lib) = which(&cmd, None) {
lib = llvm_lib.to_str().unwrap().to_owned();
}
}
}
if lib.is_empty() {
name = String::from("lib.exe");
match windows_registry::find(&target, "lib.exe") {
Some(t) => t,
None => self.cmd("lib.exe"),
}
} else {
name = lib;
self.cmd(&name)
}
} else if target.contains("illumos") {
// The default 'ar' on illumos uses a non-standard flags,
// but the OS comes bundled with a GNU-compatible variant.
//
// Use the GNU-variant to match other Unix systems.
name = format!("g{}", tool);
self.cmd(&name)
} else if self.get_host()? != target {
match self.prefix_for_target(&target) {
Some(p) => {
// GCC uses $target-gcc-ar, whereas binutils uses $target-ar -- try both.
// Prefer -ar if it exists, as builds of `-gcc-ar` have been observed to be
// outright broken (such as when targetting freebsd with `--disable-lto`
// toolchain where the archiver attempts to load the LTO plugin anyway but
// fails to find one).
//
// The same applies to ranlib.
let mut chosen = default;
for &infix in &["", "-gcc"] {
let target_p = format!("{}{}-{}", p, infix, tool);
if Command::new(&target_p).output().is_ok() {
chosen = target_p;
break;
}
}
name = chosen;
self.cmd(&name)
}
None => {
name = default;
self.cmd(&name)
}
}
} else {
name = default;
self.cmd(&name)
}
}
};
Ok((tool, name))
}
fn prefix_for_target(&self, target: &str) -> Option<String> {
// Put aside RUSTC_LINKER's prefix to be used as second choice, after CROSS_COMPILE
let linker_prefix = self
.getenv("RUSTC_LINKER")
.and_then(|var| var.strip_suffix("-gcc").map(str::to_string));
// CROSS_COMPILE is of the form: "arm-linux-gnueabi-"
let cc_env = self.getenv("CROSS_COMPILE");
let cross_compile = cc_env.as_ref().map(|s| s.trim_end_matches('-').to_owned());
cross_compile.or(linker_prefix).or(match &target[..] {
// Note: there is no `aarch64-pc-windows-gnu` target, only `-gnullvm`
"aarch64-pc-windows-gnullvm" => Some("aarch64-w64-mingw32"),
"aarch64-uwp-windows-gnu" => Some("aarch64-w64-mingw32"),
"aarch64-unknown-linux-gnu" => Some("aarch64-linux-gnu"),
"aarch64-unknown-linux-musl" => Some("aarch64-linux-musl"),
"aarch64-unknown-netbsd" => Some("aarch64--netbsd"),
"arm-unknown-linux-gnueabi" => Some("arm-linux-gnueabi"),
"armv4t-unknown-linux-gnueabi" => Some("arm-linux-gnueabi"),
"armv5te-unknown-linux-gnueabi" => Some("arm-linux-gnueabi"),
"armv5te-unknown-linux-musleabi" => Some("arm-linux-gnueabi"),
"arm-frc-linux-gnueabi" => Some("arm-frc-linux-gnueabi"),
"arm-unknown-linux-gnueabihf" => Some("arm-linux-gnueabihf"),
"arm-unknown-linux-musleabi" => Some("arm-linux-musleabi"),
"arm-unknown-linux-musleabihf" => Some("arm-linux-musleabihf"),
"arm-unknown-netbsd-eabi" => Some("arm--netbsdelf-eabi"),
"armv6-unknown-netbsd-eabihf" => Some("armv6--netbsdelf-eabihf"),
"armv7-unknown-linux-gnueabi" => Some("arm-linux-gnueabi"),
"armv7-unknown-linux-gnueabihf" => Some("arm-linux-gnueabihf"),
"armv7-unknown-linux-musleabihf" => Some("arm-linux-musleabihf"),
"armv7neon-unknown-linux-gnueabihf" => Some("arm-linux-gnueabihf"),
"armv7neon-unknown-linux-musleabihf" => Some("arm-linux-musleabihf"),
"thumbv7-unknown-linux-gnueabihf" => Some("arm-linux-gnueabihf"),
"thumbv7-unknown-linux-musleabihf" => Some("arm-linux-musleabihf"),
"thumbv7neon-unknown-linux-gnueabihf" => Some("arm-linux-gnueabihf"),
"thumbv7neon-unknown-linux-musleabihf" => Some("arm-linux-musleabihf"),
"armv7-unknown-netbsd-eabihf" => Some("armv7--netbsdelf-eabihf"),
"hexagon-unknown-linux-musl" => Some("hexagon-linux-musl"),
"i586-unknown-linux-musl" => Some("musl"),
"i686-pc-windows-gnu" => Some("i686-w64-mingw32"),
"i686-uwp-windows-gnu" => Some("i686-w64-mingw32"),
"i686-unknown-linux-gnu" => self.find_working_gnu_prefix(&[
"i686-linux-gnu",
"x86_64-linux-gnu", // transparently support gcc-multilib
]), // explicit None if not found, so caller knows to fall back
"i686-unknown-linux-musl" => Some("musl"),
"i686-unknown-netbsd" => Some("i486--netbsdelf"),
"loongarch64-unknown-linux-gnu" => Some("loongarch64-linux-gnu"),
"mips-unknown-linux-gnu" => Some("mips-linux-gnu"),
"mips-unknown-linux-musl" => Some("mips-linux-musl"),
"mipsel-unknown-linux-gnu" => Some("mipsel-linux-gnu"),
"mipsel-unknown-linux-musl" => Some("mipsel-linux-musl"),
"mips64-unknown-linux-gnuabi64" => Some("mips64-linux-gnuabi64"),
"mips64el-unknown-linux-gnuabi64" => Some("mips64el-linux-gnuabi64"),
"mipsisa32r6-unknown-linux-gnu" => Some("mipsisa32r6-linux-gnu"),
"mipsisa32r6el-unknown-linux-gnu" => Some("mipsisa32r6el-linux-gnu"),
"mipsisa64r6-unknown-linux-gnuabi64" => Some("mipsisa64r6-linux-gnuabi64"),
"mipsisa64r6el-unknown-linux-gnuabi64" => Some("mipsisa64r6el-linux-gnuabi64"),
"powerpc-unknown-linux-gnu" => Some("powerpc-linux-gnu"),
"powerpc-unknown-linux-gnuspe" => Some("powerpc-linux-gnuspe"),
"powerpc-unknown-netbsd" => Some("powerpc--netbsd"),
"powerpc64-unknown-linux-gnu" => Some("powerpc-linux-gnu"),
"powerpc64le-unknown-linux-gnu" => Some("powerpc64le-linux-gnu"),
"riscv32i-unknown-none-elf" => self.find_working_gnu_prefix(&[
"riscv32-unknown-elf",
"riscv64-unknown-elf",
"riscv-none-embed",
]),
"riscv32imac-unknown-none-elf" => self.find_working_gnu_prefix(&[
"riscv32-unknown-elf",
"riscv64-unknown-elf",
"riscv-none-embed",
]),
"riscv32imac-unknown-xous-elf" => self.find_working_gnu_prefix(&[
"riscv32-unknown-elf",
"riscv64-unknown-elf",
"riscv-none-embed",
]),
"riscv32imc-esp-espidf" => Some("riscv32-esp-elf"),
"riscv32imc-unknown-none-elf" => self.find_working_gnu_prefix(&[
"riscv32-unknown-elf",
"riscv64-unknown-elf",
"riscv-none-embed",
]),
"riscv64gc-unknown-none-elf" => self.find_working_gnu_prefix(&[
"riscv64-unknown-elf",
"riscv32-unknown-elf",
"riscv-none-embed",
]),
"riscv64imac-unknown-none-elf" => self.find_working_gnu_prefix(&[
"riscv64-unknown-elf",
"riscv32-unknown-elf",
"riscv-none-embed",
]),
"riscv64gc-unknown-linux-gnu" => Some("riscv64-linux-gnu"),
"riscv32gc-unknown-linux-gnu" => Some("riscv32-linux-gnu"),
"riscv64gc-unknown-linux-musl" => Some("riscv64-linux-musl"),
"riscv32gc-unknown-linux-musl" => Some("riscv32-linux-musl"),
"riscv64gc-unknown-netbsd" => Some("riscv64--netbsd"),
"s390x-unknown-linux-gnu" => Some("s390x-linux-gnu"),
"sparc-unknown-linux-gnu" => Some("sparc-linux-gnu"),
"sparc64-unknown-linux-gnu" => Some("sparc64-linux-gnu"),
"sparc64-unknown-netbsd" => Some("sparc64--netbsd"),
"sparcv9-sun-solaris" => Some("sparcv9-sun-solaris"),
"armv7a-none-eabi" => Some("arm-none-eabi"),
"armv7a-none-eabihf" => Some("arm-none-eabi"),
"armebv7r-none-eabi" => Some("arm-none-eabi"),
"armebv7r-none-eabihf" => Some("arm-none-eabi"),
"armv7r-none-eabi" => Some("arm-none-eabi"),
"armv7r-none-eabihf" => Some("arm-none-eabi"),
"thumbv6m-none-eabi" => Some("arm-none-eabi"),
"thumbv7em-none-eabi" => Some("arm-none-eabi"),
"thumbv7em-none-eabihf" => Some("arm-none-eabi"),
"thumbv7m-none-eabi" => Some("arm-none-eabi"),
"thumbv8m.base-none-eabi" => Some("arm-none-eabi"),
"thumbv8m.main-none-eabi" => Some("arm-none-eabi"),
"thumbv8m.main-none-eabihf" => Some("arm-none-eabi"),
"x86_64-pc-windows-gnu" => Some("x86_64-w64-mingw32"),
"x86_64-pc-windows-gnullvm" => Some("x86_64-w64-mingw32"),
"x86_64-uwp-windows-gnu" => Some("x86_64-w64-mingw32"),
"x86_64-rumprun-netbsd" => Some("x86_64-rumprun-netbsd"),
"x86_64-unknown-linux-gnu" => self.find_working_gnu_prefix(&[
"x86_64-linux-gnu", // rustfmt wrap
]), // explicit None if not found, so caller knows to fall back
"x86_64-unknown-linux-musl" => Some("musl"),
"x86_64-unknown-netbsd" => Some("x86_64--netbsd"),
_ => None,
}
.map(|x| x.to_owned()))
}
/// Some platforms have multiple, compatible, canonical prefixes. Look through
/// each possible prefix for a compiler that exists and return it. The prefixes
/// should be ordered from most-likely to least-likely.
fn find_working_gnu_prefix(&self, prefixes: &[&'static str]) -> Option<&'static str> {
let suffix = if self.cpp { "-g++" } else { "-gcc" };
let extension = std::env::consts::EXE_SUFFIX;
// Loop through PATH entries searching for each toolchain. This ensures that we
// are more likely to discover the toolchain early on, because chances are good
// that the desired toolchain is in one of the higher-priority paths.
env::var_os("PATH")
.as_ref()
.and_then(|path_entries| {
env::split_paths(path_entries).find_map(|path_entry| {
for prefix in prefixes {
let target_compiler = format!("{}{}{}", prefix, suffix, extension);
if path_entry.join(&target_compiler).exists() {
return Some(prefix);
}
}
None
})
})
.map(|prefix| *prefix)
.or_else(||
// If no toolchain was found, provide the first toolchain that was passed in.
// This toolchain has been shown not to exist, however it will appear in the
// error that is shown to the user which should make it easier to search for
// where it should be obtained.
prefixes.first().map(|prefix| *prefix))
}
fn get_target(&self) -> Result<Arc<str>, Error> {
match &self.target {
Some(t) => Ok(t.clone()),
None => self.getenv_unwrap("TARGET"),
}
}
fn get_host(&self) -> Result<Arc<str>, Error> {
match &self.host {
Some(h) => Ok(h.clone()),
None => self.getenv_unwrap("HOST"),
}
}
fn get_opt_level(&self) -> Result<Arc<str>, Error> {
match &self.opt_level {
Some(ol) => Ok(ol.clone()),
None => self.getenv_unwrap("OPT_LEVEL"),
}
}
fn get_debug(&self) -> bool {
self.debug.unwrap_or_else(|| match self.getenv("DEBUG") {
Some(s) => &*s != "false",
None => false,
})
}
fn get_dwarf_version(&self) -> Option<u32> {
// Tentatively matches the DWARF version defaults as of rustc 1.62.
let target = self.get_target().ok()?;
if target.contains("android")
|| target.contains("apple")
|| target.contains("dragonfly")
|| target.contains("freebsd")
|| target.contains("netbsd")
|| target.contains("openbsd")
|| target.contains("windows-gnu")
{
Some(2)
} else if target.contains("linux") {
Some(4)
} else {
None
}
}
fn get_force_frame_pointer(&self) -> bool {
self.force_frame_pointer.unwrap_or_else(|| self.get_debug())
}
fn get_out_dir(&self) -> Result<Cow<'_, Path>, Error> {
match &self.out_dir {
Some(p) => Ok(Cow::Borrowed(&**p)),
None => env::var_os("OUT_DIR")
.map(PathBuf::from)
.map(Cow::Owned)
.ok_or_else(|| {
Error::new(
ErrorKind::EnvVarNotFound,
"Environment variable OUT_DIR not defined.",
)
}),
}
}
fn getenv(&self, v: &str) -> Option<Arc<str>> {
// Returns true for environment variables cargo sets for build scripts:
// https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-build-scripts
//
// This handles more of the vars than we actually use (it tries to check
// complete-ish set), just to avoid needing maintenance if/when new
// calls to `getenv`/`getenv_unwrap` are added.
fn provided_by_cargo(envvar: &str) -> bool {
match envvar {
v if v.starts_with("CARGO") || v.starts_with("RUSTC") => true,
"HOST" | "TARGET" | "RUSTDOC" | "OUT_DIR" | "OPT_LEVEL" | "DEBUG" | "PROFILE"
| "NUM_JOBS" | "RUSTFLAGS" => true,
_ => false,
}
}
let mut cache = self.env_cache.lock().unwrap();
if let Some(val) = cache.get(v) {
return val.clone();
}
if self.emit_rerun_if_env_changed && !provided_by_cargo(v) {
self.print(&format_args!("cargo:rerun-if-env-changed={}", v));
}
let r = env::var(v).ok().map(Arc::from);
self.print(&format_args!("{} = {:?}", v, r));
cache.insert(v.to_string(), r.clone());
r
}
fn getenv_unwrap(&self, v: &str) -> Result<Arc<str>, Error> {
match self.getenv(v) {
Some(s) => Ok(s),
None => Err(Error::new(
ErrorKind::EnvVarNotFound,
format!("Environment variable {} not defined.", v),
)),
}
}
fn getenv_with_target_prefixes(&self, var_base: &str) -> Result<Arc<str>, Error> {
let target = self.get_target()?;
let host = self.get_host()?;
let kind = if host == target { "HOST" } else { "TARGET" };
let target_u = target.replace("-", "_");
let res = self
.getenv(&format!("{}_{}", var_base, target))
.or_else(|| self.getenv(&format!("{}_{}", var_base, target_u)))
.or_else(|| self.getenv(&format!("{}_{}", kind, var_base)))
.or_else(|| self.getenv(var_base));
match res {
Some(res) => Ok(res),
None => Err(Error::new(
ErrorKind::EnvVarNotFound,
format!("Could not find environment variable {}.", var_base),
)),
}
}
fn envflags(&self, name: &str) -> Result<Vec<String>, Error> {
Ok(self
.getenv_with_target_prefixes(name)?
.split_ascii_whitespace()
.map(|slice| slice.to_string())
.collect())
}
fn print(&self, s: &dyn Display) {
if self.cargo_metadata {
println!("{}", s);
}
}
fn fix_env_for_apple_os(&self, cmd: &mut Command) -> Result<(), Error> {
let target = self.get_target()?;
let host = self.get_host()?;
if host.contains("apple-darwin") && target.contains("apple-darwin") {
// If, for example, `cargo` runs during the build of an XCode project, then `SDKROOT` environment variable
// would represent the current target, and this is the problem for us, if we want to compile something
// for the host, when host != target.
// We can not just remove `SDKROOT`, because, again, for example, XCode add to PATH
// /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
// and `cc` from this path can not find system include files, like `pthread.h`, if `SDKROOT`
// is not set
if let Ok(sdkroot) = env::var("SDKROOT") {
if !sdkroot.contains("MacOSX") {
let macos_sdk = self.apple_sdk_root("macosx")?;
cmd.env("SDKROOT", macos_sdk);
}
}
// Additionally, `IPHONEOS_DEPLOYMENT_TARGET` must not be set when using the Xcode linker at
// "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld",
// although this is apparently ignored when using the linker at "/usr/bin/ld".
cmd.env_remove("IPHONEOS_DEPLOYMENT_TARGET");
}
Ok(())
}
fn apple_sdk_root(&self, sdk: &str) -> Result<OsString, Error> {
let mut cache = self
.apple_sdk_root_cache
.lock()
.expect("apple_sdk_root_cache lock failed");
if let Some(ret) = cache.get(sdk) {
return Ok(ret.clone());
}
let sdk_path = run_output(
self.cmd("xcrun")
.arg("--show-sdk-path")
.arg("--sdk")
.arg(sdk),
"xcrun",
)?;
let sdk_path = match String::from_utf8(sdk_path) {
Ok(p) => p,
Err(_) => {
return Err(Error::new(
ErrorKind::IOError,
"Unable to determine Apple SDK path.",
));
}
};
let ret: OsString = sdk_path.trim().into();
cache.insert(sdk.into(), ret.clone());
Ok(ret)
}
fn cuda_file_count(&self) -> usize {
self.files
.iter()
.filter(|file| file.extension() == Some(OsStr::new("cu")))
.count()
}
}
impl Default for Build {
fn default() -> Build {
Build::new()
}
}
impl Tool {
fn new(path: PathBuf) -> Self {
Tool::with_features(path, None, false)
}
fn with_clang_driver(path: PathBuf, clang_driver: Option<&str>) -> Self {
Self::with_features(path, clang_driver, false)
}
#[cfg(windows)]
/// Explicitly set the `ToolFamily`, skipping name-based detection.
fn with_family(path: PathBuf, family: ToolFamily) -> Self {
Self {
path: path,
cc_wrapper_path: None,
cc_wrapper_args: Vec::new(),
args: Vec::new(),
env: Vec::new(),
family: family,
cuda: false,
removed_args: Vec::new(),
}
}
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") {
ToolFamily::Msvc { clang_cl: true }
} else if fname.ends_with("cl") || fname == "cl.exe" {
ToolFamily::Msvc { clang_cl: false }
} else if fname.contains("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,
cc_wrapper_args: Vec::new(),
args: Vec::new(),
env: Vec::new(),
family: family,
cuda: cuda,
removed_args: Vec::new(),
}
}
/// Add an argument to be stripped from the final command arguments.
fn remove_arg(&mut self, flag: OsString) {
self.removed_args.push(flag);
}
/// Push an "exotic" flag to the end of the compiler's arguments list.
///
/// Nvidia compiler accepts only the most common compiler flags like `-D`,
/// `-I`, `-c`, etc. Options meant specifically for the underlying
/// host C++ compiler have to be prefixed with '-Xcompiler`.
/// [Another possible future application for this function is passing
/// clang-specific flags to clang-cl, which otherwise accepts only
/// MSVC-specific options.]
fn push_cc_arg(&mut self, flag: OsString) {
if self.cuda {
self.args.push("-Xcompiler".into());
}
self.args.push(flag);
}
/// Checks if an argument or flag has already been specified or conflicts.
///
/// Currently only checks optimization flags.
fn is_duplicate_opt_arg(&self, flag: &OsString) -> bool {
let flag = flag.to_str().unwrap();
let mut chars = flag.chars();
// Only duplicate check compiler flags
if self.is_like_msvc() {
if chars.next() != Some('/') {
return false;
}
} else if self.is_like_gnu() || self.is_like_clang() {
if chars.next() != Some('-') {
return false;
}
}
// Check for existing optimization flags (-O, /O)
if chars.next() == Some('O') {
return self
.args()
.iter()
.any(|ref a| a.to_str().unwrap_or("").chars().nth(1) == Some('O'));
}
// TODO Check for existing -m..., -m...=..., /arch:... flags
return false;
}
/// Don't push optimization arg if it conflicts with existing args.
fn push_opt_unless_duplicate(&mut self, flag: OsString) {
if self.is_duplicate_opt_arg(&flag) {
println!("Info: Ignoring duplicate arg {:?}", &flag);
} else {
self.push_cc_arg(flag);
}
}
/// Converts this compiler into a `Command` that's ready to be run.
///
/// This is useful for when the compiler needs to be executed and the
/// command returned will already have the initial arguments and environment
/// variables configured.
pub fn to_command(&self) -> Command {
let mut cmd = match self.cc_wrapper_path {
Some(ref cc_wrapper_path) => {
let mut cmd = Command::new(&cc_wrapper_path);
cmd.arg(&self.path);
cmd
}
None => Command::new(&self.path),
};
cmd.args(&self.cc_wrapper_args);
let value = self
.args
.iter()
.filter(|a| !self.removed_args.contains(a))
.collect::<Vec<_>>();
cmd.args(&value);
for &(ref k, ref v) in self.env.iter() {
cmd.env(k, v);
}
cmd
}
/// Returns the path for this compiler.
///
/// Note that this may not be a path to a file on the filesystem, e.g. "cc",
/// but rather something which will be resolved when a process is spawned.
pub fn path(&self) -> &Path {
&self.path
}
/// Returns the default set of arguments to the compiler needed to produce
/// executables for the target this compiler generates.
pub fn args(&self) -> &[OsString] {
&self.args
}
/// Returns the set of environment variables needed for this compiler to
/// operate.
///
/// This is typically only used for MSVC compilers currently.
pub fn env(&self) -> &[(OsString, OsString)] {
&self.env
}
/// Returns the compiler command in format of CC environment variable.
/// Or empty string if CC env was not present
///
/// This is typically used by configure script
pub fn cc_env(&self) -> OsString {
match self.cc_wrapper_path {
Some(ref cc_wrapper_path) => {
let mut cc_env = cc_wrapper_path.as_os_str().to_owned();
cc_env.push(" ");
cc_env.push(self.path.to_path_buf().into_os_string());
for arg in self.cc_wrapper_args.iter() {
cc_env.push(" ");
cc_env.push(arg);
}
cc_env
}
None => OsString::from(""),
}
}
/// Returns the compiler flags in format of CFLAGS environment variable.
/// Important here - this will not be CFLAGS from env, its internal gcc's flags to use as CFLAGS
/// This is typically used by configure script
pub fn cflags_env(&self) -> OsString {
let mut flags = OsString::new();
for (i, arg) in self.args.iter().enumerate() {
if i > 0 {
flags.push(" ");
}
flags.push(arg);
}
flags
}
/// Whether the tool is GNU Compiler Collection-like.
pub fn is_like_gnu(&self) -> bool {
self.family == ToolFamily::Gnu
}
/// Whether the tool is Clang-like.
pub fn is_like_clang(&self) -> bool {
self.family == ToolFamily::Clang
}
/// Whether the tool is MSVC-like.
pub fn is_like_msvc(&self) -> bool {
match self.family {
ToolFamily::Msvc { .. } => true,
_ => false,
}
}
}
fn wait_on_child(cmd: &Command, program: &str, child: &mut Child) -> Result<(), Error> {
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
),
));
}
};
println!("{}", status);
if status.success() {
Ok(())
} else {
Err(Error::new(
ErrorKind::ToolExecError,
format!(
"Command {:?} with args {:?} did not execute successfully (status code {}).",
cmd, program, status
),
))
}
}
#[cfg(feature = "parallel")]
fn try_wait_on_child(
cmd: &Command,
program: &str,
child: &mut Child,
stdout: &mut dyn io::Write,
) -> Result<Option<()>, Error> {
match child.try_wait() {
Ok(Some(status)) => {
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) => Err(Error::new(
ErrorKind::ToolExecError,
format!(
"Failed to wait on spawned child process, command {:?} with args {:?}: {}.",
cmd, program, e
),
)),
}
}
fn run_inner(cmd: &mut Command, program: &str, pipe_writer: File) -> Result<(), Error> {
let mut child = spawn(cmd, program, pipe_writer)?;
wait_on_child(cmd, program, &mut child)
}
fn run(cmd: &mut Command, program: &str, print: &PrintThread) -> Result<(), Error> {
run_inner(cmd, program, print.pipe_writer_cloned()?.unwrap())?;
Ok(())
}
fn run_output(cmd: &mut Command, program: &str) -> Result<Vec<u8>, Error> {
cmd.stdout(Stdio::piped());
let mut print = PrintThread::new()?;
let mut child = spawn(cmd, program, print.pipe_writer().take().unwrap())?;
let mut stdout = vec![];
child
.stdout
.take()
.unwrap()
.read_to_end(&mut stdout)
.unwrap();
wait_on_child(cmd, program, &mut child)?;
Ok(stdout)
}
fn spawn(cmd: &mut Command, program: &str, pipe_writer: File) -> 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());
}
}
println!("running: {:?}", cmd);
let cmd = ResetStderr(cmd);
match cmd.0.stderr(pipe_writer).spawn() {
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
),
)),
}
}
fn fail(s: &str) -> ! {
eprintln!("\n\nerror occurred: {}\n\n", s);
std::process::exit(1);
}
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);
}
}
// Use by default minimum available API level
// See note about naming here
// https://android.googlesource.com/platform/ndk/+/refs/heads/ndk-release-r21/docs/BuildSystemMaintainers.md#Clang
static NEW_STANDALONE_ANDROID_COMPILERS: [&str; 4] = [
"aarch64-linux-android21-clang",
"armv7a-linux-androideabi16-clang",
"i686-linux-android16-clang",
"x86_64-linux-android21-clang",
];
// New "standalone" C/C++ cross-compiler executables from recent Android NDK
// are just shell scripts that call main clang binary (from Android NDK) with
// proper `--target` argument.
//
// For example, armv7a-linux-androideabi16-clang passes
// `--target=armv7a-linux-androideabi16` to clang.
// So to construct proper command line check if
// `--target` argument would be passed or not to clang
fn android_clang_compiler_uses_target_arg_internally(clang_path: &Path) -> bool {
if let Some(filename) = clang_path.file_name() {
if let Some(filename_str) = filename.to_str() {
if let Some(idx) = filename_str.rfind("-") {
return filename_str.split_at(idx).0.contains("android");
}
}
}
false
}
#[test]
fn test_android_clang_compiler_uses_target_arg_internally() {
for version in 16..21 {
assert!(android_clang_compiler_uses_target_arg_internally(
&PathBuf::from(format!("armv7a-linux-androideabi{}-clang", version))
));
assert!(android_clang_compiler_uses_target_arg_internally(
&PathBuf::from(format!("armv7a-linux-androideabi{}-clang++", version))
));
}
assert!(!android_clang_compiler_uses_target_arg_internally(
&PathBuf::from("clang-i686-linux-android")
));
assert!(!android_clang_compiler_uses_target_arg_internally(
&PathBuf::from("clang")
));
assert!(!android_clang_compiler_uses_target_arg_internally(
&PathBuf::from("clang++")
));
}
fn autodetect_android_compiler(target: &str, host: &str, gnu: &str, clang: &str) -> String {
let new_clang_key = match target {
"aarch64-linux-android" => Some("aarch64"),
"armv7-linux-androideabi" => Some("armv7a"),
"i686-linux-android" => Some("i686"),
"x86_64-linux-android" => Some("x86_64"),
_ => None,
};
let new_clang = new_clang_key
.map(|key| {
NEW_STANDALONE_ANDROID_COMPILERS
.iter()
.find(|x| x.starts_with(key))
})
.unwrap_or(None);
if let Some(new_clang) = new_clang {
if Command::new(new_clang).output().is_ok() {
return (*new_clang).into();
}
}
let target = target
.replace("armv7neon", "arm")
.replace("armv7", "arm")
.replace("thumbv7neon", "arm")
.replace("thumbv7", "arm");
let gnu_compiler = format!("{}-{}", target, gnu);
let clang_compiler = format!("{}-{}", target, clang);
// On Windows, the Android clang compiler is provided as a `.cmd` file instead
// of a `.exe` file. `std::process::Command` won't run `.cmd` files unless the
// `.cmd` is explicitly appended to the command name, so we do that here.
let clang_compiler_cmd = format!("{}-{}.cmd", target, clang);
// Check if gnu compiler is present
// if not, use clang
if Command::new(&gnu_compiler).output().is_ok() {
gnu_compiler
} else if host.contains("windows") && Command::new(&clang_compiler_cmd).output().is_ok() {
clang_compiler_cmd
} else {
clang_compiler
}
}
// Rust and clang/cc don't agree on how to name the target.
fn map_darwin_target_from_rust_to_compiler_architecture(target: &str) -> Option<&'static str> {
if target.contains("x86_64h") {
Some("x86_64h")
} else if target.contains("x86_64") {
Some("x86_64")
} else if target.contains("arm64e") {
Some("arm64e")
} else if target.contains("aarch64") {
Some("arm64")
} else if target.contains("i686") {
Some("i386")
} else if target.contains("powerpc") {
Some("ppc")
} else if target.contains("powerpc64") {
Some("ppc64")
} else {
None
}
}
fn which(tool: &Path, path_entries: Option<OsString>) -> Option<PathBuf> {
fn check_exe(exe: &mut PathBuf) -> bool {
let exe_ext = std::env::consts::EXE_EXTENSION;
exe.exists() || (!exe_ext.is_empty() && exe.set_extension(exe_ext) && exe.exists())
}
// If |tool| is not just one "word," assume it's an actual path...
if tool.components().count() > 1 {
let mut exe = PathBuf::from(tool);
return if check_exe(&mut exe) { Some(exe) } else { None };
}
// Loop through PATH entries searching for the |tool|.
let path_entries = path_entries.or(env::var_os("PATH"))?;
env::split_paths(&path_entries).find_map(|path_entry| {
let mut exe = path_entry.join(tool);
return if check_exe(&mut exe) { Some(exe) } else { None };
})
}
// search for |prog| on 'programs' path in '|cc| -print-search-dirs' output
fn search_programs(cc: &mut Command, prog: &str) -> Option<PathBuf> {
let search_dirs = run_output(cc.arg("-print-search-dirs"), "cc").ok()?;
// clang driver appears to be forcing UTF-8 output even on Windows,
// hence from_utf8 is assumed to be usable in all cases.
let search_dirs = std::str::from_utf8(&search_dirs).ok()?;
for dirs in search_dirs.split(|c| c == '\r' || c == '\n') {
if let Some(path) = dirs.strip_prefix("programs: =") {
return which(Path::new(prog), Some(OsString::from(path)));
}
}
None
}
#[derive(Clone, Copy, PartialEq)]
enum AsmFileExt {
/// `.asm` files. On MSVC targets, we assume these should be passed to MASM
/// (`ml{,64}.exe`).
DotAsm,
/// `.s` or `.S` files, which do not have the special handling on MSVC targets.
DotS,
}
impl AsmFileExt {
fn from_path(file: &Path) -> Option<Self> {
if let Some(ext) = file.extension() {
if let Some(ext) = ext.to_str() {
let ext = ext.to_lowercase();
match &*ext {
"asm" => return Some(AsmFileExt::DotAsm),
"s" => return Some(AsmFileExt::DotS),
_ => return None,
}
}
}
None
}
}
struct PrintThread {
handle: Option<JoinHandle<()>>,
pipe_writer: Option<File>,
}
impl PrintThread {
fn new() -> Result<Self, Error> {
let (pipe_reader, pipe_writer) = os_pipe::pipe()?;
// Capture the standard error coming from compilation, and write it out
// with cargo:warning= prefixes. Note that this is a bit wonky to avoid
// requiring the output to be UTF-8, we instead just ship bytes from one
// location to another.
let print = thread::spawn(move || {
let mut stderr = BufReader::with_capacity(4096, pipe_reader);
let mut line = Vec::with_capacity(20);
let stdout = io::stdout();
// read_until returns 0 on Eof
while stderr.read_until(b'\n', &mut line).unwrap() != 0 {
{
let mut stdout = stdout.lock();
stdout.write_all(b"cargo:warning=").unwrap();
stdout.write_all(&line).unwrap();
stdout.write_all(b"\n").unwrap();
}
// read_until does not clear the buffer
line.clear();
}
});
Ok(Self {
handle: Some(print),
pipe_writer: Some(pipe_writer),
})
}
fn pipe_writer(&mut self) -> &mut Option<File> {
&mut self.pipe_writer
}
fn pipe_writer_cloned(&self) -> Result<Option<File>, Error> {
self.pipe_writer
.as_ref()
.map(File::try_clone)
.transpose()
.map_err(From::from)
}
}
impl Drop for PrintThread {
fn drop(&mut self) {
// Drop pipe_writer first to avoid deadlock
self.pipe_writer.take();
self.handle.take().unwrap().join().unwrap();
}
}