1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! C-compiler probing and detection.
13 //! This module will fill out the `cc` and `cxx` maps of `Build` by looking for
14 //! C and C++ compilers for each target configured. A compiler is found through
15 //! a number of vectors (in order of precedence)
17 //! 1. Configuration via `target.$target.cc` in `config.toml`.
18 //! 2. Configuration via `target.$target.android-ndk` in `config.toml`, if
20 //! 3. Special logic to probe on OpenBSD
21 //! 4. The `CC_$target` environment variable.
22 //! 5. The `CC` environment variable.
25 //! Some of this logic is implemented here, but much of it is farmed out to the
26 //! `gcc` crate itself, so we end up having the same fallbacks as there.
27 //! Similar logic is then used to find a C++ compiler, just some s/cc/c++/ is
30 //! It is intended that after this module has run no C/C++ compiler will
31 //! ever be probed for. Instead the compilers found here will be used for
34 use std::process::Command;
36 use build_helper::{cc2ar, output};
42 pub fn find(build: &mut Build) {
43 // For all targets we're going to need a C compiler for building some shims
44 // and such as well as for being a linker for Rust code.
46 // This includes targets that aren't necessarily passed on the commandline
47 // (FIXME: Perhaps it shouldn't?)
48 for target in &build.config.target {
49 let mut cfg = gcc::Config::new();
50 cfg.cargo_metadata(false).opt_level(0).debug(false)
51 .target(target).host(&build.build);
53 let config = build.config.target_config.get(target);
54 if let Some(cc) = config.and_then(|c| c.cc.as_ref()) {
57 set_compiler(&mut cfg, "gcc", target, config, build);
60 let compiler = cfg.get_compiler();
61 let ar = cc2ar(compiler.path(), target);
62 build.verbose(&format!("CC_{} = {:?}", target, compiler.path()));
63 if let Some(ref ar) = ar {
64 build.verbose(&format!("AR_{} = {:?}", target, ar));
66 build.cc.insert(target.to_string(), (compiler, ar));
69 // For all host triples we need to find a C++ compiler as well
71 // This includes hosts that aren't necessarily passed on the commandline
72 // (FIXME: Perhaps it shouldn't?)
73 for host in &build.config.host {
74 let mut cfg = gcc::Config::new();
75 cfg.cargo_metadata(false).opt_level(0).debug(false).cpp(true)
76 .target(host).host(&build.build);
77 let config = build.config.target_config.get(host);
78 if let Some(cxx) = config.and_then(|c| c.cxx.as_ref()) {
81 set_compiler(&mut cfg, "g++", host, config, build);
83 let compiler = cfg.get_compiler();
84 build.verbose(&format!("CXX_{} = {:?}", host, compiler.path()));
85 build.cxx.insert(host.to_string(), compiler);
89 fn set_compiler(cfg: &mut gcc::Config,
92 config: Option<&Target>,
95 // When compiling for android we may have the NDK configured in the
96 // config.toml in which case we look there. Otherwise the default
97 // compiler already takes into account the triple in question.
98 t if t.contains("android") => {
99 if let Some(ndk) = config.and_then(|c| c.ndk.as_ref()) {
100 let target = target.replace("armv7", "arm");
101 let compiler = format!("{}-{}", target, gnu_compiler);
102 cfg.compiler(ndk.join("bin").join(compiler));
106 // The default gcc version from OpenBSD may be too old, try using egcc,
107 // which is a gcc version from ports, if this is the case.
108 t if t.contains("openbsd") => {
109 let c = cfg.get_compiler();
110 if !c.path().ends_with(gnu_compiler) {
114 let output = output(c.to_command().arg("--version"));
115 let i = match output.find(" 4.") {
119 match output[i + 3..].chars().next().unwrap() {
123 let alternative = format!("e{}", gnu_compiler);
124 if Command::new(&alternative).output().is_ok() {
125 cfg.compiler(alternative);
129 "mips-unknown-linux-musl" => {
130 if cfg.get_compiler().path().to_str() == Some("gcc") {
131 cfg.compiler("mips-linux-musl-gcc");
134 "mipsel-unknown-linux-musl" => {
135 if cfg.get_compiler().path().to_str() == Some("gcc") {
136 cfg.compiler("mipsel-linux-musl-gcc");
140 t if t.contains("musl") => {
141 if let Some(root) = build.musl_root(target) {
142 let guess = root.join("bin/musl-gcc");