//! 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>, definitions: Vec<(Arc, Option>)>, objects: Vec>, flags: Vec>, flags_supported: Vec>, known_flag_support_status: Arc>>, ar_flags: Vec>, asm_flags: Vec>, no_default_flags: bool, files: Vec>, cpp: bool, cpp_link_stdlib: Option>>, cpp_set_stdlib: Option>, cuda: bool, cudart: Option>, std: Option>, target: Option>, host: Option>, out_dir: Option>, opt_level: Option>, debug: Option, force_frame_pointer: Option, env: Vec<(Arc, Arc)>, compiler: Option>, archiver: Option>, ranlib: Option>, cargo_metadata: bool, link_lib_modifiers: Vec>, pic: Option, use_plt: Option, static_crt: Option, shared_flag: Option, static_flag: Option, warnings_into_errors: bool, warnings: Option, extra_warnings: Option, env_cache: Arc>>>>, apple_sdk_root_cache: Arc>>, 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>) -> Error { Error { kind, message: message.into(), } } } impl From 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, cc_wrapper_args: Vec, args: Vec, env: Vec<(OsString, OsString)>, family: ToolFamily, cuda: bool, removed_args: Vec, } /// 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) { 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>(&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

(&mut self, dirs: P) -> &mut Build where P: IntoIterator, P::Item: AsRef, { 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>>(&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>(&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 { 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 { 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>(&mut self, p: P) -> &mut Build { self.files.push(p.as_ref().into()); self } /// Add files which will be compiled pub fn files

(&mut self, p: P) -> &mut Build where P: IntoIterator, P::Item: AsRef, { 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>>( &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>>( &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>(&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>(&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>(&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>(&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(&mut self, a: A, b: B) -> &mut Build where A: AsRef, B: AsRef, { 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 = None; fn _assert_sync() {} _assert_sync::(); 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, 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 { 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 { 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>(&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 { 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 = 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::() { 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 { // 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, Vec)> { 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, 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 { 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 { 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 { 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 = 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 { // 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, Error> { match &self.target { Some(t) => Ok(t.clone()), None => self.getenv_unwrap("TARGET"), } } fn get_host(&self) -> Result, Error> { match &self.host { Some(h) => Ok(h.clone()), None => self.getenv_unwrap("HOST"), } } fn get_opt_level(&self) -> Result, 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 { // 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, 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> { // 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, 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, 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, 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 { 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::>(); 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, 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, 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 { 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) -> Option { 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 { 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 { 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>, pipe_writer: Option, } impl PrintThread { fn new() -> Result { 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 { &mut self.pipe_writer } fn pipe_writer_cloned(&self) -> Result, 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(); } }