src/toolchain.rs

   1 use std::path::PathBuf;
   2
   3 use rustc_middle::bug;
   4 use rustc_session::Session;
   5 use rustc_target::spec::LinkerFlavor;
   6
   7 /// Tries to infer the path of a binary for the target toolchain from the linker name.
   8 pub(crate) fn get_toolchain_binary(sess: &Session, tool: &str) -> PathBuf {
   9     let (mut linker, _linker_flavor) = linker_and_flavor(sess);
  10     let linker_file_name = linker
  11         .file_name()
  12         .and_then(|name| name.to_str())
  13         .unwrap_or_else(|| sess.fatal("couldn't extract file name from specified linker"));
  14
  15     if linker_file_name == "ld.lld" {
  16         if tool != "ld" {
  17             linker.set_file_name(tool)
  18         }
  19     } else {
  20         let tool_file_name = linker_file_name
  21             .replace("ld", tool)
  22             .replace("gcc", tool)
  23             .replace("clang", tool)
  24             .replace("cc", tool);
  25
  26         linker.set_file_name(tool_file_name)
  27     }
  28
  29     linker
  30 }
  31
  32 // Adapted from https://github.com/rust-lang/rust/blob/5db778affee7c6600c8e7a177c48282dab3f6292/src/librustc_codegen_ssa/back/link.rs#L848-L931
  33 fn linker_and_flavor(sess: &Session) -> (PathBuf, LinkerFlavor) {
  34     fn infer_from(
  35         sess: &Session,
  36         linker: Option<PathBuf>,
  37         flavor: Option<LinkerFlavor>,
  38     ) -> Option<(PathBuf, LinkerFlavor)> {
  39         match (linker, flavor) {
  40             (Some(linker), Some(flavor)) => Some((linker, flavor)),
  41             // only the linker flavor is known; use the default linker for the selected flavor
  42             (None, Some(flavor)) => Some((
  43                 PathBuf::from(match flavor {
  44                     LinkerFlavor::Em => {
  45                         if cfg!(windows) {
  46                             "emcc.bat"
  47                         } else {
  48                             "emcc"
  49                         }
  50                     }
  51                     LinkerFlavor::Gcc => {
  52                         if cfg!(any(target_os = "solaris", target_os = "illumos")) {
  53                             // On historical Solaris systems, "cc" may have
  54                             // been Sun Studio, which is not flag-compatible
  55                             // with "gcc".  This history casts a long shadow,
  56                             // and many modern illumos distributions today
  57                             // ship GCC as "gcc" without also making it
  58                             // available as "cc".
  59                             "gcc"
  60                         } else {
  61                             "cc"
  62                         }
  63                     }
  64                     LinkerFlavor::Ld => "ld",
  65                     LinkerFlavor::Msvc => "link.exe",
  66                     LinkerFlavor::Lld(_) => "lld",
  67                     LinkerFlavor::PtxLinker => "rust-ptx-linker",
  68                 }),
  69                 flavor,
  70             )),
  71             (Some(linker), None) => {
  72                 let stem = linker
  73                     .file_stem()
  74                     .and_then(|stem| stem.to_str())
  75                     .unwrap_or_else(|| {
  76                         sess.fatal("couldn't extract file stem from specified linker")
  77                     });
  78
  79                 let flavor = if stem == "emcc" {
  80                     LinkerFlavor::Em
  81                 } else if stem == "gcc"
  82                     || stem.ends_with("-gcc")
  83                     || stem == "clang"
  84                     || stem.ends_with("-clang")
  85                 {
  86                     LinkerFlavor::Gcc
  87                 } else if stem == "ld" || stem == "ld.lld" || stem.ends_with("-ld") {
  88                     LinkerFlavor::Ld
  89                 } else if stem == "link" || stem == "lld-link" {
  90                     LinkerFlavor::Msvc
  91                 } else if stem == "lld" || stem == "rust-lld" {
  92                     LinkerFlavor::Lld(sess.target.target.options.lld_flavor)
  93                 } else {
  94                     // fall back to the value in the target spec
  95                     sess.target.target.linker_flavor
  96                 };
  97
  98                 Some((linker, flavor))
  99             }
 100             (None, None) => None,
 101         }
 102     }
 103
 104     // linker and linker flavor specified via command line have precedence over what the target
 105     // specification specifies
 106     if let Some(ret) = infer_from(
 107         sess,
 108         sess.opts.cg.linker.clone(),
 109         sess.opts.cg.linker_flavor,
 110     ) {
 111         return ret;
 112     }
 113
 114     if let Some(ret) = infer_from(
 115         sess,
 116         sess.target.target.options.linker.clone().map(PathBuf::from),
 117         Some(sess.target.target.linker_flavor),
 118     ) {
 119         return ret;
 120     }
 121
 122     bug!("Not enough information provided to determine how to invoke the linker");
 123 }