src/bootstrap/cc.rs

   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.
   4 //
   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.
  10
  11 //! C-compiler probing and detection.
  12 //!
  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)
  16 //!
  17 //! 1. Configuration via `target.$target.cc` in `config.toml`.
  18 //! 2. Configuration via `target.$target.android-ndk` in `config.toml`, if
  19 //!    applicable
  20 //! 3. Special logic to probe on OpenBSD
  21 //! 4. The `CC_$target` environment variable.
  22 //! 5. The `CC` environment variable.
  23 //! 6. "cc"
  24 //!
  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
  28 //! used.
  29 //!
  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
  32 //! everything.
  33
  34 use std::process::Command;
  35
  36 use build_helper::{cc2ar, output};
  37 use gcc;
  38
  39 use Build;
  40 use config::Target;
  41
  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.
  45     for target in build.config.target.iter() {
  46         let mut cfg = gcc::Config::new();
  47         cfg.cargo_metadata(false).opt_level(0).debug(false)
  48            .target(target).host(&build.config.build);
  49
  50         let config = build.config.target_config.get(target);
  51         if let Some(cc) = config.and_then(|c| c.cc.as_ref()) {
  52             cfg.compiler(cc);
  53         } else {
  54             set_compiler(&mut cfg, "gcc", target, config);
  55         }
  56
  57         let compiler = cfg.get_compiler();
  58         let ar = cc2ar(compiler.path(), target);
  59         build.verbose(&format!("CC_{} = {:?}", target, compiler.path()));
  60         if let Some(ref ar) = ar {
  61             build.verbose(&format!("AR_{} = {:?}", target, ar));
  62         }
  63         build.cc.insert(target.to_string(), (compiler, ar));
  64     }
  65
  66     // For all host triples we need to find a C++ compiler as well
  67     for host in build.config.host.iter() {
  68         let mut cfg = gcc::Config::new();
  69         cfg.cargo_metadata(false).opt_level(0).debug(false).cpp(true)
  70            .target(host).host(&build.config.build);
  71         let config = build.config.target_config.get(host);
  72         if let Some(cxx) = config.and_then(|c| c.cxx.as_ref()) {
  73             cfg.compiler(cxx);
  74         } else {
  75             set_compiler(&mut cfg, "g++", host, config);
  76         }
  77         let compiler = cfg.get_compiler();
  78         build.verbose(&format!("CXX_{} = {:?}", host, compiler.path()));
  79         build.cxx.insert(host.to_string(), compiler);
  80     }
  81 }
  82
  83 fn set_compiler(cfg: &mut gcc::Config,
  84                 gnu_compiler: &str,
  85                 target: &str,
  86                 config: Option<&Target>) {
  87     match target {
  88         // When compiling for android we may have the NDK configured in the
  89         // config.toml in which case we look there. Otherwise the default
  90         // compiler already takes into account the triple in question.
  91         t if t.contains("android") => {
  92             if let Some(ndk) = config.and_then(|c| c.ndk.as_ref()) {
  93                 let target = target.replace("armv7", "arm");
  94                 let compiler = format!("{}-{}", target, gnu_compiler);
  95                 cfg.compiler(ndk.join("bin").join(compiler));
  96             }
  97         }
  98
  99         // The default gcc version from OpenBSD may be too old, try using egcc,
 100         // which is a gcc version from ports, if this is the case.
 101         t if t.contains("openbsd") => {
 102             let c = cfg.get_compiler();
 103             if !c.path().ends_with(gnu_compiler) {
 104                 return
 105             }
 106
 107             let output = output(c.to_command().arg("--version"));
 108             let i = match output.find(" 4.") {
 109                 Some(i) => i,
 110                 None => return,
 111             };
 112             match output[i + 3..].chars().next().unwrap() {
 113                 '0' ... '6' => {}
 114                 _ => return,
 115             }
 116             let alternative = format!("e{}", gnu_compiler);
 117             if Command::new(&alternative).output().is_ok() {
 118                 cfg.compiler(alternative);
 119             }
 120         }
 121
 122         _ => {}
 123     }
 124 }