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|
/// For all the linkers we support, and information they might
/// need out of the shared crate context before we get rid of it.
use rustc::session::{Session, config};
use rustc::session::search_paths::PathKind;
use rustc::middle::dependency_format::Linkage;
use rustc::middle::cstore::LibSource;
use rustc_target::spec::LinkerFlavor;
use rustc::hir::def_id::CrateNum;
use super::command::Command;
use crate::CrateInfo;
use cc::windows_registry;
use std::fs;
use std::path::{Path, PathBuf};
use std::env;
pub fn remove(sess: &Session, path: &Path) {
if let Err(e) = fs::remove_file(path) {
sess.err(&format!("failed to remove {}: {}",
path.display(),
e));
}
}
// The third parameter is for env vars, used on windows to set up the
// path for MSVC to find its DLLs, and gcc to find its bundled
// toolchain
pub fn get_linker(sess: &Session, linker: &Path, flavor: LinkerFlavor) -> (PathBuf, Command) {
let msvc_tool = windows_registry::find_tool(&sess.opts.target_triple.triple(), "link.exe");
// If our linker looks like a batch script on Windows then to execute this
// we'll need to spawn `cmd` explicitly. This is primarily done to handle
// emscripten where the linker is `emcc.bat` and needs to be spawned as
// `cmd /c emcc.bat ...`.
//
// This worked historically but is needed manually since #42436 (regression
// was tagged as #42791) and some more info can be found on #44443 for
// emscripten itself.
let mut cmd = match linker.to_str() {
Some(linker) if cfg!(windows) && linker.ends_with(".bat") => Command::bat_script(linker),
_ => match flavor {
LinkerFlavor::Lld(f) => Command::lld(linker, f),
LinkerFlavor::Msvc
if sess.opts.cg.linker.is_none() && sess.target.target.options.linker.is_none() =>
{
Command::new(msvc_tool.as_ref().map(|t| t.path()).unwrap_or(linker))
},
_ => Command::new(linker),
}
};
// The compiler's sysroot often has some bundled tools, so add it to the
// PATH for the child.
let mut new_path = sess.host_filesearch(PathKind::All)
.get_tools_search_paths();
let mut msvc_changed_path = false;
if sess.target.target.options.is_like_msvc {
if let Some(ref tool) = msvc_tool {
cmd.args(tool.args());
for &(ref k, ref v) in tool.env() {
if k == "PATH" {
new_path.extend(env::split_paths(v));
msvc_changed_path = true;
} else {
cmd.env(k, v);
}
}
}
}
if !msvc_changed_path {
if let Some(path) = env::var_os("PATH") {
new_path.extend(env::split_paths(&path));
}
}
cmd.env("PATH", env::join_paths(new_path).unwrap());
(linker.to_path_buf(), cmd)
}
pub fn each_linked_rlib(sess: &Session,
info: &CrateInfo,
f: &mut dyn FnMut(CrateNum, &Path)) -> Result<(), String> {
let crates = info.used_crates_static.iter();
let fmts = sess.dependency_formats.borrow();
let fmts = fmts.get(&config::CrateType::Executable)
.or_else(|| fmts.get(&config::CrateType::Staticlib))
.or_else(|| fmts.get(&config::CrateType::Cdylib))
.or_else(|| fmts.get(&config::CrateType::ProcMacro));
let fmts = match fmts {
Some(f) => f,
None => return Err("could not find formats for rlibs".to_string())
};
for &(cnum, ref path) in crates {
match fmts.get(cnum.as_usize() - 1) {
Some(&Linkage::NotLinked) |
Some(&Linkage::IncludedFromDylib) => continue,
Some(_) => {}
None => return Err("could not find formats for rlibs".to_string())
}
let name = &info.crate_name[&cnum];
let path = match *path {
LibSource::Some(ref p) => p,
LibSource::MetadataOnly => {
return Err(format!("could not find rlib for: `{}`, found rmeta (metadata) file",
name))
}
LibSource::None => {
return Err(format!("could not find rlib for: `{}`", name))
}
};
f(cnum, &path);
}
Ok(())
}
/// Returns a boolean indicating whether the specified crate should be ignored
/// during LTO.
///
/// Crates ignored during LTO are not lumped together in the "massive object
/// file" that we create and are linked in their normal rlib states. See
/// comments below for what crates do not participate in LTO.
///
/// It's unusual for a crate to not participate in LTO. Typically only
/// compiler-specific and unstable crates have a reason to not participate in
/// LTO.
pub fn ignored_for_lto(sess: &Session, info: &CrateInfo, cnum: CrateNum) -> bool {
// If our target enables builtin function lowering in LLVM then the
// crates providing these functions don't participate in LTO (e.g.
// no_builtins or compiler builtins crates).
!sess.target.target.options.no_builtins &&
(info.compiler_builtins == Some(cnum) || info.is_no_builtins.contains(&cnum))
}
pub fn linker_and_flavor(sess: &Session) -> (PathBuf, LinkerFlavor) {
fn infer_from(
sess: &Session,
linker: Option<PathBuf>,
flavor: Option<LinkerFlavor>,
) -> Option<(PathBuf, LinkerFlavor)> {
match (linker, flavor) {
(Some(linker), Some(flavor)) => Some((linker, flavor)),
// only the linker flavor is known; use the default linker for the selected flavor
(None, Some(flavor)) => Some((PathBuf::from(match flavor {
LinkerFlavor::Em => if cfg!(windows) { "emcc.bat" } else { "emcc" },
LinkerFlavor::Gcc => "cc",
LinkerFlavor::Ld => "ld",
LinkerFlavor::Msvc => "link.exe",
LinkerFlavor::Lld(_) => "lld",
LinkerFlavor::PtxLinker => "rust-ptx-linker",
}), flavor)),
(Some(linker), None) => {
let stem = if linker.extension().and_then(|ext| ext.to_str()) == Some("exe") {
linker.file_stem().and_then(|stem| stem.to_str())
} else {
linker.to_str()
}.unwrap_or_else(|| {
sess.fatal("couldn't extract file stem from specified linker");
}).to_owned();
let flavor = if stem == "emcc" {
LinkerFlavor::Em
} else if stem == "gcc" || stem.ends_with("-gcc") {
LinkerFlavor::Gcc
} else if stem == "ld" || stem == "ld.lld" || stem.ends_with("-ld") {
LinkerFlavor::Ld
} else if stem == "link" || stem == "lld-link" {
LinkerFlavor::Msvc
} else if stem == "lld" || stem == "rust-lld" {
LinkerFlavor::Lld(sess.target.target.options.lld_flavor)
} else {
// fall back to the value in the target spec
sess.target.target.linker_flavor
};
Some((linker, flavor))
},
(None, None) => None,
}
}
// linker and linker flavor specified via command line have precedence over what the target
// specification specifies
if let Some(ret) = infer_from(sess, sess.opts.cg.linker.clone(), sess.opts.cg.linker_flavor) {
return ret;
}
if let Some(ret) = infer_from(
sess,
sess.target.target.options.linker.clone().map(PathBuf::from),
Some(sess.target.target.linker_flavor),
) {
return ret;
}
bug!("Not enough information provided to determine how to invoke the linker");
}
|
