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};
43 pub fn find(build: &mut Build) {
44 // For all targets we're going to need a C compiler for building some shims
45 // and such as well as for being a linker for Rust code.
47 // This includes targets that aren't necessarily passed on the commandline
48 // (FIXME: Perhaps it shouldn't?)
49 for target in &build.config.target {
50 let mut cfg = gcc::Config::new();
51 cfg.cargo_metadata(false).opt_level(0).debug(false)
52 .target(target).host(&build.build);
54 let config = build.config.target_config.get(&target);
55 if let Some(cc) = config.and_then(|c| c.cc.as_ref()) {
58 set_compiler(&mut cfg, "gcc", *target, config, build);
61 let compiler = cfg.get_compiler();
62 let ar = cc2ar(compiler.path(), target);
63 build.verbose(&format!("CC_{} = {:?}", target, compiler.path()));
64 if let Some(ref ar) = ar {
65 build.verbose(&format!("AR_{} = {:?}", target, ar));
67 build.cc.insert(*target, (compiler, ar));
70 // For all host triples we need to find a C++ compiler as well
72 // This includes hosts that aren't necessarily passed on the commandline
73 // (FIXME: Perhaps it shouldn't?)
74 for host in &build.config.host {
75 let mut cfg = gcc::Config::new();
76 cfg.cargo_metadata(false).opt_level(0).debug(false).cpp(true)
77 .target(host).host(&build.build);
78 let config = build.config.target_config.get(host);
79 if let Some(cxx) = config.and_then(|c| c.cxx.as_ref()) {
82 set_compiler(&mut cfg, "g++", *host, config, build);
84 let compiler = cfg.get_compiler();
85 build.verbose(&format!("CXX_{} = {:?}", host, compiler.path()));
86 build.cxx.insert(*host, compiler);
90 fn set_compiler(cfg: &mut gcc::Config,
92 target: Interned<String>,
93 config: Option<&Target>,
96 // When compiling for android we may have the NDK configured in the
97 // config.toml in which case we look there. Otherwise the default
98 // compiler already takes into account the triple in question.
99 t if t.contains("android") => {
100 if let Some(ndk) = config.and_then(|c| c.ndk.as_ref()) {
101 let target = target.replace("armv7", "arm");
102 let compiler = format!("{}-{}", target, gnu_compiler);
103 cfg.compiler(ndk.join("bin").join(compiler));
107 // The default gcc version from OpenBSD may be too old, try using egcc,
108 // which is a gcc version from ports, if this is the case.
109 t if t.contains("openbsd") => {
110 let c = cfg.get_compiler();
111 if !c.path().ends_with(gnu_compiler) {
115 let output = output(c.to_command().arg("--version"));
116 let i = match output.find(" 4.") {
120 match output[i + 3..].chars().next().unwrap() {
124 let alternative = format!("e{}", gnu_compiler);
125 if Command::new(&alternative).output().is_ok() {
126 cfg.compiler(alternative);
130 "mips-unknown-linux-musl" => {
131 if cfg.get_compiler().path().to_str() == Some("gcc") {
132 cfg.compiler("mips-linux-musl-gcc");
135 "mipsel-unknown-linux-musl" => {
136 if cfg.get_compiler().path().to_str() == Some("gcc") {
137 cfg.compiler("mipsel-linux-musl-gcc");
141 t if t.contains("musl") => {
142 if let Some(root) = build.musl_root(target) {
143 let guess = root.join("bin/musl-gcc");