1860 lines
73 KiB
Rust
1860 lines
73 KiB
Rust
use rustc::middle::cstore::{EncodedMetadata, LibSource, NativeLibrary, NativeLibraryKind};
|
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use rustc::middle::dependency_format::Linkage;
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use rustc_data_structures::fx::FxHashSet;
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use rustc_fs_util::fix_windows_verbatim_for_gcc;
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use rustc_hir::def_id::CrateNum;
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use rustc_session::config::{
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self, CFGuard, DebugInfo, OutputFilenames, OutputType, PrintRequest, Sanitizer,
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};
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use rustc_session::output::{check_file_is_writeable, invalid_output_for_target, out_filename};
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use rustc_session::search_paths::PathKind;
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/// For all the linkers we support, and information they might
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/// need out of the shared crate context before we get rid of it.
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use rustc_session::{filesearch, Session};
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use rustc_span::symbol::Symbol;
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use rustc_target::spec::{LinkerFlavor, PanicStrategy, RelroLevel};
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use super::archive::ArchiveBuilder;
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use super::command::Command;
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use super::linker::Linker;
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use super::rpath::{self, RPathConfig};
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use crate::{
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looks_like_rust_object_file, CodegenResults, CrateInfo, METADATA_FILENAME,
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RLIB_BYTECODE_EXTENSION,
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};
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use cc::windows_registry;
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use tempfile::{Builder as TempFileBuilder, TempDir};
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use std::ascii;
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use std::char;
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use std::env;
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use std::ffi::OsString;
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use std::fmt;
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use std::fs;
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use std::io;
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use std::path::{Path, PathBuf};
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use std::process::{ExitStatus, Output, Stdio};
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use std::str;
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pub fn remove(sess: &Session, path: &Path) {
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if let Err(e) = fs::remove_file(path) {
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sess.err(&format!("failed to remove {}: {}", path.display(), e));
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}
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}
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/// Performs the linkage portion of the compilation phase. This will generate all
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/// of the requested outputs for this compilation session.
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pub fn link_binary<'a, B: ArchiveBuilder<'a>>(
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sess: &'a Session,
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codegen_results: &CodegenResults,
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outputs: &OutputFilenames,
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crate_name: &str,
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target_cpu: &str,
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) {
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let _timer = sess.timer("link_binary");
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let output_metadata = sess.opts.output_types.contains_key(&OutputType::Metadata);
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for &crate_type in sess.crate_types.borrow().iter() {
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// Ignore executable crates if we have -Z no-codegen, as they will error.
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if (sess.opts.debugging_opts.no_codegen || !sess.opts.output_types.should_codegen())
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&& !output_metadata
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&& crate_type == config::CrateType::Executable
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{
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continue;
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}
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if invalid_output_for_target(sess, crate_type) {
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bug!(
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"invalid output type `{:?}` for target os `{}`",
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crate_type,
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sess.opts.target_triple
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);
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}
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sess.time("link_binary_check_files_are_writeable", || {
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for obj in codegen_results.modules.iter().filter_map(|m| m.object.as_ref()) {
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check_file_is_writeable(obj, sess);
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}
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});
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let tmpdir = TempFileBuilder::new()
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.prefix("rustc")
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.tempdir()
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.unwrap_or_else(|err| sess.fatal(&format!("couldn't create a temp dir: {}", err)));
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if outputs.outputs.should_codegen() {
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let out_filename = out_filename(sess, crate_type, outputs, crate_name);
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match crate_type {
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config::CrateType::Rlib => {
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let _timer = sess.timer("link_rlib");
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link_rlib::<B>(
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sess,
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codegen_results,
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RlibFlavor::Normal,
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&out_filename,
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&tmpdir,
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)
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.build();
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}
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config::CrateType::Staticlib => {
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link_staticlib::<B>(sess, codegen_results, &out_filename, &tmpdir);
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}
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_ => {
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link_natively::<B>(
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sess,
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crate_type,
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&out_filename,
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codegen_results,
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tmpdir.path(),
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target_cpu,
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);
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}
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}
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if sess.opts.json_artifact_notifications {
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sess.parse_sess.span_diagnostic.emit_artifact_notification(&out_filename, "link");
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}
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}
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if sess.opts.cg.save_temps {
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let _ = tmpdir.into_path();
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}
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}
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// Remove the temporary object file and metadata if we aren't saving temps
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sess.time("link_binary_remove_temps", || {
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if !sess.opts.cg.save_temps {
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if sess.opts.output_types.should_codegen()
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&& !preserve_objects_for_their_debuginfo(sess)
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{
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for obj in codegen_results.modules.iter().filter_map(|m| m.object.as_ref()) {
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remove(sess, obj);
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}
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}
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for obj in codegen_results.modules.iter().filter_map(|m| m.bytecode_compressed.as_ref())
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{
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remove(sess, obj);
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}
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if let Some(ref metadata_module) = codegen_results.metadata_module {
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if let Some(ref obj) = metadata_module.object {
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remove(sess, obj);
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}
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}
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if let Some(ref allocator_module) = codegen_results.allocator_module {
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if let Some(ref obj) = allocator_module.object {
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remove(sess, obj);
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}
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if let Some(ref bc) = allocator_module.bytecode_compressed {
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remove(sess, bc);
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}
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}
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}
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});
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}
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// The third parameter is for env vars, used on windows to set up the
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// path for MSVC to find its DLLs, and gcc to find its bundled
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// toolchain
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pub fn get_linker(sess: &Session, linker: &Path, flavor: LinkerFlavor) -> (PathBuf, Command) {
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let msvc_tool = windows_registry::find_tool(&sess.opts.target_triple.triple(), "link.exe");
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// If our linker looks like a batch script on Windows then to execute this
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// we'll need to spawn `cmd` explicitly. This is primarily done to handle
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// emscripten where the linker is `emcc.bat` and needs to be spawned as
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// `cmd /c emcc.bat ...`.
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//
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// This worked historically but is needed manually since #42436 (regression
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// was tagged as #42791) and some more info can be found on #44443 for
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// emscripten itself.
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let mut cmd = match linker.to_str() {
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Some(linker) if cfg!(windows) && linker.ends_with(".bat") => Command::bat_script(linker),
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_ => match flavor {
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LinkerFlavor::Lld(f) => Command::lld(linker, f),
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LinkerFlavor::Msvc
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if sess.opts.cg.linker.is_none() && sess.target.target.options.linker.is_none() =>
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{
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Command::new(msvc_tool.as_ref().map(|t| t.path()).unwrap_or(linker))
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}
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_ => Command::new(linker),
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},
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};
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// UWP apps have API restrictions enforced during Store submissions.
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// To comply with the Windows App Certification Kit,
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// MSVC needs to link with the Store versions of the runtime libraries (vcruntime, msvcrt, etc).
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let t = &sess.target.target;
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if flavor == LinkerFlavor::Msvc && t.target_vendor == "uwp" {
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if let Some(ref tool) = msvc_tool {
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let original_path = tool.path();
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if let Some(ref root_lib_path) = original_path.ancestors().nth(4) {
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let arch = match t.arch.as_str() {
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"x86_64" => Some("x64".to_string()),
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"x86" => Some("x86".to_string()),
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"aarch64" => Some("arm64".to_string()),
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_ => None,
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};
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if let Some(ref a) = arch {
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let mut arg = OsString::from("/LIBPATH:");
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arg.push(format!("{}\\lib\\{}\\store", root_lib_path.display(), a.to_string()));
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cmd.arg(&arg);
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} else {
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warn!("arch is not supported");
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}
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} else {
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warn!("MSVC root path lib location not found");
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}
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} else {
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warn!("link.exe not found");
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}
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}
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// The compiler's sysroot often has some bundled tools, so add it to the
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// PATH for the child.
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let mut new_path = sess.host_filesearch(PathKind::All).get_tools_search_paths();
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let mut msvc_changed_path = false;
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if sess.target.target.options.is_like_msvc {
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if let Some(ref tool) = msvc_tool {
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cmd.args(tool.args());
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for &(ref k, ref v) in tool.env() {
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if k == "PATH" {
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new_path.extend(env::split_paths(v));
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msvc_changed_path = true;
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} else {
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cmd.env(k, v);
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}
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}
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}
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}
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if !msvc_changed_path {
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if let Some(path) = env::var_os("PATH") {
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new_path.extend(env::split_paths(&path));
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}
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}
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cmd.env("PATH", env::join_paths(new_path).unwrap());
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(linker.to_path_buf(), cmd)
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}
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pub fn each_linked_rlib(
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info: &CrateInfo,
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f: &mut dyn FnMut(CrateNum, &Path),
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) -> Result<(), String> {
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let crates = info.used_crates_static.iter();
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let mut fmts = None;
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for (ty, list) in info.dependency_formats.iter() {
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match ty {
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config::CrateType::Executable
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| config::CrateType::Staticlib
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| config::CrateType::Cdylib
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| config::CrateType::ProcMacro => {
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fmts = Some(list);
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break;
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}
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_ => {}
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||
}
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}
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let fmts = match fmts {
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Some(f) => f,
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None => return Err("could not find formats for rlibs".to_string()),
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};
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for &(cnum, ref path) in crates {
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match fmts.get(cnum.as_usize() - 1) {
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Some(&Linkage::NotLinked) | Some(&Linkage::IncludedFromDylib) => continue,
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Some(_) => {}
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None => return Err("could not find formats for rlibs".to_string()),
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}
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let name = &info.crate_name[&cnum];
|
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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)),
|
||
};
|
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f(cnum, &path);
|
||
}
|
||
Ok(())
|
||
}
|
||
|
||
/// We use a temp directory here to avoid races between concurrent rustc processes,
|
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/// such as builds in the same directory using the same filename for metadata while
|
||
/// building an `.rlib` (stomping over one another), or writing an `.rmeta` into a
|
||
/// directory being searched for `extern crate` (observing an incomplete file).
|
||
/// The returned path is the temporary file containing the complete metadata.
|
||
pub fn emit_metadata<'a>(
|
||
sess: &'a Session,
|
||
metadata: &EncodedMetadata,
|
||
tmpdir: &TempDir,
|
||
) -> PathBuf {
|
||
let out_filename = tmpdir.path().join(METADATA_FILENAME);
|
||
let result = fs::write(&out_filename, &metadata.raw_data);
|
||
|
||
if let Err(e) = result {
|
||
sess.fatal(&format!("failed to write {}: {}", out_filename.display(), e));
|
||
}
|
||
|
||
out_filename
|
||
}
|
||
|
||
// Create an 'rlib'
|
||
//
|
||
// An rlib in its current incarnation is essentially a renamed .a file. The
|
||
// rlib primarily contains the object file of the crate, but it also contains
|
||
// all of the object files from native libraries. This is done by unzipping
|
||
// native libraries and inserting all of the contents into this archive.
|
||
fn link_rlib<'a, B: ArchiveBuilder<'a>>(
|
||
sess: &'a Session,
|
||
codegen_results: &CodegenResults,
|
||
flavor: RlibFlavor,
|
||
out_filename: &Path,
|
||
tmpdir: &TempDir,
|
||
) -> B {
|
||
info!("preparing rlib to {:?}", out_filename);
|
||
let mut ab = <B as ArchiveBuilder>::new(sess, out_filename, None);
|
||
|
||
for obj in codegen_results.modules.iter().filter_map(|m| m.object.as_ref()) {
|
||
ab.add_file(obj);
|
||
}
|
||
|
||
// Note that in this loop we are ignoring the value of `lib.cfg`. That is,
|
||
// we may not be configured to actually include a static library if we're
|
||
// adding it here. That's because later when we consume this rlib we'll
|
||
// decide whether we actually needed the static library or not.
|
||
//
|
||
// To do this "correctly" we'd need to keep track of which libraries added
|
||
// which object files to the archive. We don't do that here, however. The
|
||
// #[link(cfg(..))] feature is unstable, though, and only intended to get
|
||
// liblibc working. In that sense the check below just indicates that if
|
||
// there are any libraries we want to omit object files for at link time we
|
||
// just exclude all custom object files.
|
||
//
|
||
// Eventually if we want to stabilize or flesh out the #[link(cfg(..))]
|
||
// feature then we'll need to figure out how to record what objects were
|
||
// loaded from the libraries found here and then encode that into the
|
||
// metadata of the rlib we're generating somehow.
|
||
for lib in codegen_results.crate_info.used_libraries.iter() {
|
||
match lib.kind {
|
||
NativeLibraryKind::NativeStatic => {}
|
||
NativeLibraryKind::NativeStaticNobundle
|
||
| NativeLibraryKind::NativeFramework
|
||
| NativeLibraryKind::NativeRawDylib
|
||
| NativeLibraryKind::NativeUnknown => continue,
|
||
}
|
||
if let Some(name) = lib.name {
|
||
ab.add_native_library(name);
|
||
}
|
||
}
|
||
|
||
// After adding all files to the archive, we need to update the
|
||
// symbol table of the archive.
|
||
ab.update_symbols();
|
||
|
||
// Note that it is important that we add all of our non-object "magical
|
||
// files" *after* all of the object files in the archive. The reason for
|
||
// this is as follows:
|
||
//
|
||
// * When performing LTO, this archive will be modified to remove
|
||
// objects from above. The reason for this is described below.
|
||
//
|
||
// * When the system linker looks at an archive, it will attempt to
|
||
// determine the architecture of the archive in order to see whether its
|
||
// linkable.
|
||
//
|
||
// The algorithm for this detection is: iterate over the files in the
|
||
// archive. Skip magical SYMDEF names. Interpret the first file as an
|
||
// object file. Read architecture from the object file.
|
||
//
|
||
// * As one can probably see, if "metadata" and "foo.bc" were placed
|
||
// before all of the objects, then the architecture of this archive would
|
||
// not be correctly inferred once 'foo.o' is removed.
|
||
//
|
||
// Basically, all this means is that this code should not move above the
|
||
// code above.
|
||
match flavor {
|
||
RlibFlavor::Normal => {
|
||
// Instead of putting the metadata in an object file section, rlibs
|
||
// contain the metadata in a separate file.
|
||
ab.add_file(&emit_metadata(sess, &codegen_results.metadata, tmpdir));
|
||
|
||
// For LTO purposes, the bytecode of this library is also inserted
|
||
// into the archive.
|
||
for bytecode in
|
||
codegen_results.modules.iter().filter_map(|m| m.bytecode_compressed.as_ref())
|
||
{
|
||
ab.add_file(bytecode);
|
||
}
|
||
|
||
// After adding all files to the archive, we need to update the
|
||
// symbol table of the archive. This currently dies on macOS (see
|
||
// #11162), and isn't necessary there anyway
|
||
if !sess.target.target.options.is_like_osx {
|
||
ab.update_symbols();
|
||
}
|
||
}
|
||
|
||
RlibFlavor::StaticlibBase => {
|
||
let obj = codegen_results.allocator_module.as_ref().and_then(|m| m.object.as_ref());
|
||
if let Some(obj) = obj {
|
||
ab.add_file(obj);
|
||
}
|
||
}
|
||
}
|
||
|
||
ab
|
||
}
|
||
|
||
// Create a static archive
|
||
//
|
||
// This is essentially the same thing as an rlib, but it also involves adding
|
||
// all of the upstream crates' objects into the archive. This will slurp in
|
||
// all of the native libraries of upstream dependencies as well.
|
||
//
|
||
// Additionally, there's no way for us to link dynamic libraries, so we warn
|
||
// about all dynamic library dependencies that they're not linked in.
|
||
//
|
||
// There's no need to include metadata in a static archive, so ensure to not
|
||
// link in the metadata object file (and also don't prepare the archive with a
|
||
// metadata file).
|
||
fn link_staticlib<'a, B: ArchiveBuilder<'a>>(
|
||
sess: &'a Session,
|
||
codegen_results: &CodegenResults,
|
||
out_filename: &Path,
|
||
tempdir: &TempDir,
|
||
) {
|
||
let mut ab =
|
||
link_rlib::<B>(sess, codegen_results, RlibFlavor::StaticlibBase, out_filename, tempdir);
|
||
let mut all_native_libs = vec![];
|
||
|
||
let res = each_linked_rlib(&codegen_results.crate_info, &mut |cnum, path| {
|
||
let name = &codegen_results.crate_info.crate_name[&cnum];
|
||
let native_libs = &codegen_results.crate_info.native_libraries[&cnum];
|
||
|
||
// Here when we include the rlib into our staticlib we need to make a
|
||
// decision whether to include the extra object files along the way.
|
||
// These extra object files come from statically included native
|
||
// libraries, but they may be cfg'd away with #[link(cfg(..))].
|
||
//
|
||
// This unstable feature, though, only needs liblibc to work. The only
|
||
// use case there is where musl is statically included in liblibc.rlib,
|
||
// so if we don't want the included version we just need to skip it. As
|
||
// a result the logic here is that if *any* linked library is cfg'd away
|
||
// we just skip all object files.
|
||
//
|
||
// Clearly this is not sufficient for a general purpose feature, and
|
||
// we'd want to read from the library's metadata to determine which
|
||
// object files come from where and selectively skip them.
|
||
let skip_object_files = native_libs
|
||
.iter()
|
||
.any(|lib| lib.kind == NativeLibraryKind::NativeStatic && !relevant_lib(sess, lib));
|
||
ab.add_rlib(
|
||
path,
|
||
&name.as_str(),
|
||
are_upstream_rust_objects_already_included(sess)
|
||
&& !ignored_for_lto(sess, &codegen_results.crate_info, cnum),
|
||
skip_object_files,
|
||
)
|
||
.unwrap();
|
||
|
||
all_native_libs.extend(codegen_results.crate_info.native_libraries[&cnum].iter().cloned());
|
||
});
|
||
if let Err(e) = res {
|
||
sess.fatal(&e);
|
||
}
|
||
|
||
ab.update_symbols();
|
||
ab.build();
|
||
|
||
if !all_native_libs.is_empty() {
|
||
if sess.opts.prints.contains(&PrintRequest::NativeStaticLibs) {
|
||
print_native_static_libs(sess, &all_native_libs);
|
||
}
|
||
}
|
||
}
|
||
|
||
// Create a dynamic library or executable
|
||
//
|
||
// This will invoke the system linker/cc to create the resulting file. This
|
||
// links to all upstream files as well.
|
||
fn link_natively<'a, B: ArchiveBuilder<'a>>(
|
||
sess: &'a Session,
|
||
crate_type: config::CrateType,
|
||
out_filename: &Path,
|
||
codegen_results: &CodegenResults,
|
||
tmpdir: &Path,
|
||
target_cpu: &str,
|
||
) {
|
||
info!("preparing {:?} to {:?}", crate_type, out_filename);
|
||
let (linker, flavor) = linker_and_flavor(sess);
|
||
|
||
let any_dynamic_crate = crate_type == config::CrateType::Dylib
|
||
|| codegen_results.crate_info.dependency_formats.iter().any(|(ty, list)| {
|
||
*ty == crate_type && list.iter().any(|&linkage| linkage == Linkage::Dynamic)
|
||
});
|
||
|
||
// The invocations of cc share some flags across platforms
|
||
let (pname, mut cmd) = get_linker(sess, &linker, flavor);
|
||
|
||
if let Some(args) = sess.target.target.options.pre_link_args.get(&flavor) {
|
||
cmd.args(args);
|
||
}
|
||
if let Some(args) = sess.target.target.options.pre_link_args_crt.get(&flavor) {
|
||
if sess.crt_static(Some(crate_type)) {
|
||
cmd.args(args);
|
||
}
|
||
}
|
||
if let Some(ref args) = sess.opts.debugging_opts.pre_link_args {
|
||
cmd.args(args);
|
||
}
|
||
cmd.args(&sess.opts.debugging_opts.pre_link_arg);
|
||
|
||
if sess.target.target.options.is_like_fuchsia {
|
||
let prefix = match sess.opts.debugging_opts.sanitizer {
|
||
Some(Sanitizer::Address) => "asan/",
|
||
_ => "",
|
||
};
|
||
cmd.arg(format!("--dynamic-linker={}ld.so.1", prefix));
|
||
}
|
||
|
||
let pre_link_objects = if crate_type == config::CrateType::Executable {
|
||
&sess.target.target.options.pre_link_objects_exe
|
||
} else {
|
||
&sess.target.target.options.pre_link_objects_dll
|
||
};
|
||
for obj in pre_link_objects {
|
||
cmd.arg(get_file_path(sess, obj));
|
||
}
|
||
|
||
if crate_type == config::CrateType::Executable && sess.crt_static(Some(crate_type)) {
|
||
for obj in &sess.target.target.options.pre_link_objects_exe_crt {
|
||
cmd.arg(get_file_path(sess, obj));
|
||
}
|
||
}
|
||
|
||
if sess.target.target.options.is_like_emscripten {
|
||
cmd.arg("-s");
|
||
cmd.arg(if sess.panic_strategy() == PanicStrategy::Abort {
|
||
"DISABLE_EXCEPTION_CATCHING=1"
|
||
} else {
|
||
"DISABLE_EXCEPTION_CATCHING=0"
|
||
});
|
||
}
|
||
|
||
{
|
||
let mut linker = codegen_results.linker_info.to_linker(cmd, &sess, flavor, target_cpu);
|
||
link_sanitizer_runtime(sess, crate_type, &mut *linker);
|
||
link_args::<B>(
|
||
&mut *linker,
|
||
flavor,
|
||
sess,
|
||
crate_type,
|
||
tmpdir,
|
||
out_filename,
|
||
codegen_results,
|
||
);
|
||
cmd = linker.finalize();
|
||
}
|
||
if let Some(args) = sess.target.target.options.late_link_args.get(&flavor) {
|
||
cmd.args(args);
|
||
}
|
||
if any_dynamic_crate {
|
||
if let Some(args) = sess.target.target.options.late_link_args_dynamic.get(&flavor) {
|
||
cmd.args(args);
|
||
}
|
||
} else {
|
||
if let Some(args) = sess.target.target.options.late_link_args_static.get(&flavor) {
|
||
cmd.args(args);
|
||
}
|
||
}
|
||
for obj in &sess.target.target.options.post_link_objects {
|
||
cmd.arg(get_file_path(sess, obj));
|
||
}
|
||
if sess.crt_static(Some(crate_type)) {
|
||
for obj in &sess.target.target.options.post_link_objects_crt {
|
||
cmd.arg(get_file_path(sess, obj));
|
||
}
|
||
}
|
||
if let Some(args) = sess.target.target.options.post_link_args.get(&flavor) {
|
||
cmd.args(args);
|
||
}
|
||
for &(ref k, ref v) in &sess.target.target.options.link_env {
|
||
cmd.env(k, v);
|
||
}
|
||
for k in &sess.target.target.options.link_env_remove {
|
||
cmd.env_remove(k);
|
||
}
|
||
|
||
if sess.opts.debugging_opts.print_link_args {
|
||
println!("{:?}", &cmd);
|
||
}
|
||
|
||
// May have not found libraries in the right formats.
|
||
sess.abort_if_errors();
|
||
|
||
// Invoke the system linker
|
||
info!("{:?}", &cmd);
|
||
let retry_on_segfault = env::var("RUSTC_RETRY_LINKER_ON_SEGFAULT").is_ok();
|
||
let mut prog;
|
||
let mut i = 0;
|
||
loop {
|
||
i += 1;
|
||
prog = sess.time("run_linker", || exec_linker(sess, &mut cmd, out_filename, tmpdir));
|
||
let output = match prog {
|
||
Ok(ref output) => output,
|
||
Err(_) => break,
|
||
};
|
||
if output.status.success() {
|
||
break;
|
||
}
|
||
let mut out = output.stderr.clone();
|
||
out.extend(&output.stdout);
|
||
let out = String::from_utf8_lossy(&out);
|
||
|
||
// Check to see if the link failed with "unrecognized command line option:
|
||
// '-no-pie'" for gcc or "unknown argument: '-no-pie'" for clang. If so,
|
||
// reperform the link step without the -no-pie option. This is safe because
|
||
// if the linker doesn't support -no-pie then it should not default to
|
||
// linking executables as pie. Different versions of gcc seem to use
|
||
// different quotes in the error message so don't check for them.
|
||
if sess.target.target.options.linker_is_gnu
|
||
&& flavor != LinkerFlavor::Ld
|
||
&& (out.contains("unrecognized command line option")
|
||
|| out.contains("unknown argument"))
|
||
&& out.contains("-no-pie")
|
||
&& cmd.get_args().iter().any(|e| e.to_string_lossy() == "-no-pie")
|
||
{
|
||
info!("linker output: {:?}", out);
|
||
warn!("Linker does not support -no-pie command line option. Retrying without.");
|
||
for arg in cmd.take_args() {
|
||
if arg.to_string_lossy() != "-no-pie" {
|
||
cmd.arg(arg);
|
||
}
|
||
}
|
||
info!("{:?}", &cmd);
|
||
continue;
|
||
}
|
||
|
||
// Here's a terribly awful hack that really shouldn't be present in any
|
||
// compiler. Here an environment variable is supported to automatically
|
||
// retry the linker invocation if the linker looks like it segfaulted.
|
||
//
|
||
// Gee that seems odd, normally segfaults are things we want to know
|
||
// about! Unfortunately though in rust-lang/rust#38878 we're
|
||
// experiencing the linker segfaulting on Travis quite a bit which is
|
||
// causing quite a bit of pain to land PRs when they spuriously fail
|
||
// due to a segfault.
|
||
//
|
||
// The issue #38878 has some more debugging information on it as well,
|
||
// but this unfortunately looks like it's just a race condition in
|
||
// macOS's linker with some thread pool working in the background. It
|
||
// seems that no one currently knows a fix for this so in the meantime
|
||
// we're left with this...
|
||
if !retry_on_segfault || i > 3 {
|
||
break;
|
||
}
|
||
let msg_segv = "clang: error: unable to execute command: Segmentation fault: 11";
|
||
let msg_bus = "clang: error: unable to execute command: Bus error: 10";
|
||
if out.contains(msg_segv) || out.contains(msg_bus) {
|
||
warn!(
|
||
"looks like the linker segfaulted when we tried to call it, \
|
||
automatically retrying again. cmd = {:?}, out = {}.",
|
||
cmd, out,
|
||
);
|
||
continue;
|
||
}
|
||
|
||
if is_illegal_instruction(&output.status) {
|
||
warn!(
|
||
"looks like the linker hit an illegal instruction when we \
|
||
tried to call it, automatically retrying again. cmd = {:?}, ]\
|
||
out = {}, status = {}.",
|
||
cmd, out, output.status,
|
||
);
|
||
continue;
|
||
}
|
||
|
||
#[cfg(unix)]
|
||
fn is_illegal_instruction(status: &ExitStatus) -> bool {
|
||
use std::os::unix::prelude::*;
|
||
status.signal() == Some(libc::SIGILL)
|
||
}
|
||
|
||
#[cfg(windows)]
|
||
fn is_illegal_instruction(_status: &ExitStatus) -> bool {
|
||
false
|
||
}
|
||
}
|
||
|
||
match prog {
|
||
Ok(prog) => {
|
||
fn escape_string(s: &[u8]) -> String {
|
||
str::from_utf8(s).map(|s| s.to_owned()).unwrap_or_else(|_| {
|
||
let mut x = "Non-UTF-8 output: ".to_string();
|
||
x.extend(s.iter().flat_map(|&b| ascii::escape_default(b)).map(char::from));
|
||
x
|
||
})
|
||
}
|
||
if !prog.status.success() {
|
||
let mut output = prog.stderr.clone();
|
||
output.extend_from_slice(&prog.stdout);
|
||
sess.struct_err(&format!(
|
||
"linking with `{}` failed: {}",
|
||
pname.display(),
|
||
prog.status
|
||
))
|
||
.note(&format!("{:?}", &cmd))
|
||
.note(&escape_string(&output))
|
||
.emit();
|
||
sess.abort_if_errors();
|
||
}
|
||
info!("linker stderr:\n{}", escape_string(&prog.stderr));
|
||
info!("linker stdout:\n{}", escape_string(&prog.stdout));
|
||
}
|
||
Err(e) => {
|
||
let linker_not_found = e.kind() == io::ErrorKind::NotFound;
|
||
|
||
let mut linker_error = {
|
||
if linker_not_found {
|
||
sess.struct_err(&format!("linker `{}` not found", pname.display()))
|
||
} else {
|
||
sess.struct_err(&format!("could not exec the linker `{}`", pname.display()))
|
||
}
|
||
};
|
||
|
||
linker_error.note(&e.to_string());
|
||
|
||
if !linker_not_found {
|
||
linker_error.note(&format!("{:?}", &cmd));
|
||
}
|
||
|
||
linker_error.emit();
|
||
|
||
if sess.target.target.options.is_like_msvc && linker_not_found {
|
||
sess.note_without_error(
|
||
"the msvc targets depend on the msvc linker \
|
||
but `link.exe` was not found",
|
||
);
|
||
sess.note_without_error(
|
||
"please ensure that VS 2013, VS 2015, VS 2017 or VS 2019 \
|
||
was installed with the Visual C++ option",
|
||
);
|
||
}
|
||
sess.abort_if_errors();
|
||
}
|
||
}
|
||
|
||
// On macOS, debuggers need this utility to get run to do some munging of
|
||
// the symbols. Note, though, that if the object files are being preserved
|
||
// for their debug information there's no need for us to run dsymutil.
|
||
if sess.target.target.options.is_like_osx
|
||
&& sess.opts.debuginfo != DebugInfo::None
|
||
&& !preserve_objects_for_their_debuginfo(sess)
|
||
{
|
||
if let Err(e) = Command::new("dsymutil").arg(out_filename).output() {
|
||
sess.fatal(&format!("failed to run dsymutil: {}", e))
|
||
}
|
||
}
|
||
}
|
||
|
||
fn link_sanitizer_runtime(sess: &Session, crate_type: config::CrateType, linker: &mut dyn Linker) {
|
||
let sanitizer = match &sess.opts.debugging_opts.sanitizer {
|
||
Some(s) => s,
|
||
None => return,
|
||
};
|
||
|
||
if crate_type != config::CrateType::Executable {
|
||
return;
|
||
}
|
||
|
||
let name = match sanitizer {
|
||
Sanitizer::Address => "asan",
|
||
Sanitizer::Leak => "lsan",
|
||
Sanitizer::Memory => "msan",
|
||
Sanitizer::Thread => "tsan",
|
||
};
|
||
|
||
let default_sysroot = filesearch::get_or_default_sysroot();
|
||
let default_tlib =
|
||
filesearch::make_target_lib_path(&default_sysroot, sess.opts.target_triple.triple());
|
||
let channel = option_env!("CFG_RELEASE_CHANNEL")
|
||
.map(|channel| format!("-{}", channel))
|
||
.unwrap_or_default();
|
||
|
||
match sess.opts.target_triple.triple() {
|
||
"x86_64-apple-darwin" => {
|
||
// On Apple platforms, the sanitizer is always built as a dylib, and
|
||
// LLVM will link to `@rpath/*.dylib`, so we need to specify an
|
||
// rpath to the library as well (the rpath should be absolute, see
|
||
// PR #41352 for details).
|
||
let libname = format!("rustc{}_rt.{}", channel, name);
|
||
let rpath = default_tlib.to_str().expect("non-utf8 component in path");
|
||
linker.args(&["-Wl,-rpath".into(), "-Xlinker".into(), rpath.into()]);
|
||
linker.link_dylib(Symbol::intern(&libname));
|
||
}
|
||
"x86_64-unknown-linux-gnu" | "x86_64-fuchsia" | "aarch64-fuchsia" => {
|
||
let filename = format!("librustc{}_rt.{}.a", channel, name);
|
||
let path = default_tlib.join(&filename);
|
||
linker.link_whole_rlib(&path);
|
||
}
|
||
_ => {}
|
||
}
|
||
}
|
||
|
||
/// 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 = linker.file_stem().and_then(|stem| stem.to_str()).unwrap_or_else(|| {
|
||
sess.fatal("couldn't extract file stem from specified linker")
|
||
});
|
||
|
||
let flavor = if stem == "emcc" {
|
||
LinkerFlavor::Em
|
||
} else if stem == "gcc"
|
||
|| stem.ends_with("-gcc")
|
||
|| stem == "clang"
|
||
|| stem.ends_with("-clang")
|
||
{
|
||
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");
|
||
}
|
||
|
||
/// Returns a boolean indicating whether we should preserve the object files on
|
||
/// the filesystem for their debug information. This is often useful with
|
||
/// split-dwarf like schemes.
|
||
pub fn preserve_objects_for_their_debuginfo(sess: &Session) -> bool {
|
||
// If the objects don't have debuginfo there's nothing to preserve.
|
||
if sess.opts.debuginfo == config::DebugInfo::None {
|
||
return false;
|
||
}
|
||
|
||
// If we're only producing artifacts that are archives, no need to preserve
|
||
// the objects as they're losslessly contained inside the archives.
|
||
let output_linked = sess
|
||
.crate_types
|
||
.borrow()
|
||
.iter()
|
||
.any(|&x| x != config::CrateType::Rlib && x != config::CrateType::Staticlib);
|
||
if !output_linked {
|
||
return false;
|
||
}
|
||
|
||
// If we're on OSX then the equivalent of split dwarf is turned on by
|
||
// default. The final executable won't actually have any debug information
|
||
// except it'll have pointers to elsewhere. Historically we've always run
|
||
// `dsymutil` to "link all the dwarf together" but this is actually sort of
|
||
// a bummer for incremental compilation! (the whole point of split dwarf is
|
||
// that you don't do this sort of dwarf link).
|
||
//
|
||
// Basically as a result this just means that if we're on OSX and we're
|
||
// *not* running dsymutil then the object files are the only source of truth
|
||
// for debug information, so we must preserve them.
|
||
if sess.target.target.options.is_like_osx {
|
||
match sess.opts.debugging_opts.run_dsymutil {
|
||
// dsymutil is not being run, preserve objects
|
||
Some(false) => return true,
|
||
|
||
// dsymutil is being run, no need to preserve the objects
|
||
Some(true) => return false,
|
||
|
||
// The default historical behavior was to always run dsymutil, so
|
||
// we're preserving that temporarily, but we're likely to switch the
|
||
// default soon.
|
||
None => return false,
|
||
}
|
||
}
|
||
|
||
false
|
||
}
|
||
|
||
pub fn archive_search_paths(sess: &Session) -> Vec<PathBuf> {
|
||
sess.target_filesearch(PathKind::Native).search_path_dirs()
|
||
}
|
||
|
||
enum RlibFlavor {
|
||
Normal,
|
||
StaticlibBase,
|
||
}
|
||
|
||
pub fn print_native_static_libs(sess: &Session, all_native_libs: &[NativeLibrary]) {
|
||
let lib_args: Vec<_> = all_native_libs
|
||
.iter()
|
||
.filter(|l| relevant_lib(sess, l))
|
||
.filter_map(|lib| {
|
||
let name = lib.name?;
|
||
match lib.kind {
|
||
NativeLibraryKind::NativeStaticNobundle | NativeLibraryKind::NativeUnknown => {
|
||
if sess.target.target.options.is_like_msvc {
|
||
Some(format!("{}.lib", name))
|
||
} else {
|
||
Some(format!("-l{}", name))
|
||
}
|
||
}
|
||
NativeLibraryKind::NativeFramework => {
|
||
// ld-only syntax, since there are no frameworks in MSVC
|
||
Some(format!("-framework {}", name))
|
||
}
|
||
// These are included, no need to print them
|
||
NativeLibraryKind::NativeStatic | NativeLibraryKind::NativeRawDylib => None,
|
||
}
|
||
})
|
||
.collect();
|
||
if !lib_args.is_empty() {
|
||
sess.note_without_error(
|
||
"Link against the following native artifacts when linking \
|
||
against this static library. The order and any duplication \
|
||
can be significant on some platforms.",
|
||
);
|
||
// Prefix for greppability
|
||
sess.note_without_error(&format!("native-static-libs: {}", &lib_args.join(" ")));
|
||
}
|
||
}
|
||
|
||
// Because windows-gnu target is meant to be self-contained for pure Rust code it bundles
|
||
// own mingw-w64 libraries. These libraries are usually not compatible with mingw-w64
|
||
// installed in the system. This breaks many cases where Rust is mixed with other languages
|
||
// (e.g. *-sys crates).
|
||
// We prefer system mingw-w64 libraries if they are available to avoid this issue.
|
||
fn get_crt_libs_path(sess: &Session) -> Option<PathBuf> {
|
||
fn find_exe_in_path<P>(exe_name: P) -> Option<PathBuf>
|
||
where
|
||
P: AsRef<Path>,
|
||
{
|
||
for dir in env::split_paths(&env::var_os("PATH")?) {
|
||
let full_path = dir.join(&exe_name);
|
||
if full_path.is_file() {
|
||
return Some(fix_windows_verbatim_for_gcc(&full_path));
|
||
}
|
||
}
|
||
None
|
||
}
|
||
|
||
fn probe(sess: &Session) -> Option<PathBuf> {
|
||
if let (linker, LinkerFlavor::Gcc) = linker_and_flavor(&sess) {
|
||
let linker_path = if cfg!(windows) && linker.extension().is_none() {
|
||
linker.with_extension("exe")
|
||
} else {
|
||
linker
|
||
};
|
||
if let Some(linker_path) = find_exe_in_path(linker_path) {
|
||
let mingw_arch = match &sess.target.target.arch {
|
||
x if x == "x86" => "i686",
|
||
x => x,
|
||
};
|
||
let mingw_bits = &sess.target.target.target_pointer_width;
|
||
let mingw_dir = format!("{}-w64-mingw32", mingw_arch);
|
||
// Here we have path/bin/gcc but we need path/
|
||
let mut path = linker_path;
|
||
path.pop();
|
||
path.pop();
|
||
// Loosely based on Clang MinGW driver
|
||
let probe_paths = vec![
|
||
path.join(&mingw_dir).join("lib"), // Typical path
|
||
path.join(&mingw_dir).join("sys-root/mingw/lib"), // Rare path
|
||
path.join(format!(
|
||
"lib/mingw/tools/install/mingw{}/{}/lib",
|
||
&mingw_bits, &mingw_dir
|
||
)), // Chocolatey is creative
|
||
];
|
||
for probe_path in probe_paths {
|
||
if probe_path.join("crt2.o").exists() {
|
||
return Some(probe_path);
|
||
};
|
||
}
|
||
};
|
||
};
|
||
None
|
||
}
|
||
|
||
let mut system_library_path = sess.system_library_path.borrow_mut();
|
||
match &*system_library_path {
|
||
Some(Some(compiler_libs_path)) => Some(compiler_libs_path.clone()),
|
||
Some(None) => None,
|
||
None => {
|
||
let path = probe(sess);
|
||
*system_library_path = Some(path.clone());
|
||
path
|
||
}
|
||
}
|
||
}
|
||
|
||
pub fn get_file_path(sess: &Session, name: &str) -> PathBuf {
|
||
// prefer system {,dll}crt2.o libs, see get_crt_libs_path comment for more details
|
||
if sess.target.target.llvm_target.contains("windows-gnu") {
|
||
if let Some(compiler_libs_path) = get_crt_libs_path(sess) {
|
||
let file_path = compiler_libs_path.join(name);
|
||
if file_path.exists() {
|
||
return file_path;
|
||
}
|
||
}
|
||
}
|
||
let fs = sess.target_filesearch(PathKind::Native);
|
||
let file_path = fs.get_lib_path().join(name);
|
||
if file_path.exists() {
|
||
return file_path;
|
||
}
|
||
for search_path in fs.search_paths() {
|
||
let file_path = search_path.dir.join(name);
|
||
if file_path.exists() {
|
||
return file_path;
|
||
}
|
||
}
|
||
PathBuf::from(name)
|
||
}
|
||
|
||
pub fn exec_linker(
|
||
sess: &Session,
|
||
cmd: &mut Command,
|
||
out_filename: &Path,
|
||
tmpdir: &Path,
|
||
) -> io::Result<Output> {
|
||
// When attempting to spawn the linker we run a risk of blowing out the
|
||
// size limits for spawning a new process with respect to the arguments
|
||
// we pass on the command line.
|
||
//
|
||
// Here we attempt to handle errors from the OS saying "your list of
|
||
// arguments is too big" by reinvoking the linker again with an `@`-file
|
||
// that contains all the arguments. The theory is that this is then
|
||
// accepted on all linkers and the linker will read all its options out of
|
||
// there instead of looking at the command line.
|
||
if !cmd.very_likely_to_exceed_some_spawn_limit() {
|
||
match cmd.command().stdout(Stdio::piped()).stderr(Stdio::piped()).spawn() {
|
||
Ok(child) => {
|
||
let output = child.wait_with_output();
|
||
flush_linked_file(&output, out_filename)?;
|
||
return output;
|
||
}
|
||
Err(ref e) if command_line_too_big(e) => {
|
||
info!("command line to linker was too big: {}", e);
|
||
}
|
||
Err(e) => return Err(e),
|
||
}
|
||
}
|
||
|
||
info!("falling back to passing arguments to linker via an @-file");
|
||
let mut cmd2 = cmd.clone();
|
||
let mut args = String::new();
|
||
for arg in cmd2.take_args() {
|
||
args.push_str(
|
||
&Escape {
|
||
arg: arg.to_str().unwrap(),
|
||
is_like_msvc: sess.target.target.options.is_like_msvc,
|
||
}
|
||
.to_string(),
|
||
);
|
||
args.push_str("\n");
|
||
}
|
||
let file = tmpdir.join("linker-arguments");
|
||
let bytes = if sess.target.target.options.is_like_msvc {
|
||
let mut out = Vec::with_capacity((1 + args.len()) * 2);
|
||
// start the stream with a UTF-16 BOM
|
||
for c in std::iter::once(0xFEFF).chain(args.encode_utf16()) {
|
||
// encode in little endian
|
||
out.push(c as u8);
|
||
out.push((c >> 8) as u8);
|
||
}
|
||
out
|
||
} else {
|
||
args.into_bytes()
|
||
};
|
||
fs::write(&file, &bytes)?;
|
||
cmd2.arg(format!("@{}", file.display()));
|
||
info!("invoking linker {:?}", cmd2);
|
||
let output = cmd2.output();
|
||
flush_linked_file(&output, out_filename)?;
|
||
return output;
|
||
|
||
#[cfg(unix)]
|
||
fn flush_linked_file(_: &io::Result<Output>, _: &Path) -> io::Result<()> {
|
||
Ok(())
|
||
}
|
||
|
||
#[cfg(windows)]
|
||
fn flush_linked_file(
|
||
command_output: &io::Result<Output>,
|
||
out_filename: &Path,
|
||
) -> io::Result<()> {
|
||
// On Windows, under high I/O load, output buffers are sometimes not flushed,
|
||
// even long after process exit, causing nasty, non-reproducible output bugs.
|
||
//
|
||
// File::sync_all() calls FlushFileBuffers() down the line, which solves the problem.
|
||
//
|
||
// А full writeup of the original Chrome bug can be found at
|
||
// randomascii.wordpress.com/2018/02/25/compiler-bug-linker-bug-windows-kernel-bug/amp
|
||
|
||
if let &Ok(ref out) = command_output {
|
||
if out.status.success() {
|
||
if let Ok(of) = fs::OpenOptions::new().write(true).open(out_filename) {
|
||
of.sync_all()?;
|
||
}
|
||
}
|
||
}
|
||
|
||
Ok(())
|
||
}
|
||
|
||
#[cfg(unix)]
|
||
fn command_line_too_big(err: &io::Error) -> bool {
|
||
err.raw_os_error() == Some(::libc::E2BIG)
|
||
}
|
||
|
||
#[cfg(windows)]
|
||
fn command_line_too_big(err: &io::Error) -> bool {
|
||
const ERROR_FILENAME_EXCED_RANGE: i32 = 206;
|
||
err.raw_os_error() == Some(ERROR_FILENAME_EXCED_RANGE)
|
||
}
|
||
|
||
struct Escape<'a> {
|
||
arg: &'a str,
|
||
is_like_msvc: bool,
|
||
}
|
||
|
||
impl<'a> fmt::Display for Escape<'a> {
|
||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||
if self.is_like_msvc {
|
||
// This is "documented" at
|
||
// https://docs.microsoft.com/en-us/cpp/build/reference/at-specify-a-linker-response-file
|
||
//
|
||
// Unfortunately there's not a great specification of the
|
||
// syntax I could find online (at least) but some local
|
||
// testing showed that this seemed sufficient-ish to catch
|
||
// at least a few edge cases.
|
||
write!(f, "\"")?;
|
||
for c in self.arg.chars() {
|
||
match c {
|
||
'"' => write!(f, "\\{}", c)?,
|
||
c => write!(f, "{}", c)?,
|
||
}
|
||
}
|
||
write!(f, "\"")?;
|
||
} else {
|
||
// This is documented at https://linux.die.net/man/1/ld, namely:
|
||
//
|
||
// > Options in file are separated by whitespace. A whitespace
|
||
// > character may be included in an option by surrounding the
|
||
// > entire option in either single or double quotes. Any
|
||
// > character (including a backslash) may be included by
|
||
// > prefixing the character to be included with a backslash.
|
||
//
|
||
// We put an argument on each line, so all we need to do is
|
||
// ensure the line is interpreted as one whole argument.
|
||
for c in self.arg.chars() {
|
||
match c {
|
||
'\\' | ' ' => write!(f, "\\{}", c)?,
|
||
c => write!(f, "{}", c)?,
|
||
}
|
||
}
|
||
}
|
||
Ok(())
|
||
}
|
||
}
|
||
}
|
||
|
||
fn link_args<'a, B: ArchiveBuilder<'a>>(
|
||
cmd: &mut dyn Linker,
|
||
flavor: LinkerFlavor,
|
||
sess: &'a Session,
|
||
crate_type: config::CrateType,
|
||
tmpdir: &Path,
|
||
out_filename: &Path,
|
||
codegen_results: &CodegenResults,
|
||
) {
|
||
// Linker plugins should be specified early in the list of arguments
|
||
cmd.linker_plugin_lto();
|
||
|
||
// The default library location, we need this to find the runtime.
|
||
// The location of crates will be determined as needed.
|
||
let lib_path = sess.target_filesearch(PathKind::All).get_lib_path();
|
||
|
||
// target descriptor
|
||
let t = &sess.target.target;
|
||
|
||
// prefer system mingw-w64 libs, see get_crt_libs_path comment for more details
|
||
if cfg!(windows) && sess.target.target.llvm_target.contains("windows-gnu") {
|
||
if let Some(compiler_libs_path) = get_crt_libs_path(sess) {
|
||
cmd.include_path(&compiler_libs_path);
|
||
}
|
||
}
|
||
|
||
cmd.include_path(&fix_windows_verbatim_for_gcc(&lib_path));
|
||
|
||
for obj in codegen_results.modules.iter().filter_map(|m| m.object.as_ref()) {
|
||
cmd.add_object(obj);
|
||
}
|
||
cmd.output_filename(out_filename);
|
||
|
||
if crate_type == config::CrateType::Executable && sess.target.target.options.is_like_windows {
|
||
if let Some(ref s) = codegen_results.windows_subsystem {
|
||
cmd.subsystem(s);
|
||
}
|
||
}
|
||
|
||
// If we're building something like a dynamic library then some platforms
|
||
// need to make sure that all symbols are exported correctly from the
|
||
// dynamic library.
|
||
cmd.export_symbols(tmpdir, crate_type);
|
||
|
||
// When linking a dynamic library, we put the metadata into a section of the
|
||
// executable. This metadata is in a separate object file from the main
|
||
// object file, so we link that in here.
|
||
if crate_type == config::CrateType::Dylib || crate_type == config::CrateType::ProcMacro {
|
||
let obj = codegen_results.metadata_module.as_ref().and_then(|m| m.object.as_ref());
|
||
if let Some(obj) = obj {
|
||
cmd.add_object(obj);
|
||
}
|
||
}
|
||
|
||
let obj = codegen_results.allocator_module.as_ref().and_then(|m| m.object.as_ref());
|
||
if let Some(obj) = obj {
|
||
cmd.add_object(obj);
|
||
}
|
||
|
||
// Try to strip as much out of the generated object by removing unused
|
||
// sections if possible. See more comments in linker.rs
|
||
if !sess.opts.cg.link_dead_code {
|
||
let keep_metadata = crate_type == config::CrateType::Dylib;
|
||
cmd.gc_sections(keep_metadata);
|
||
}
|
||
|
||
let used_link_args = &codegen_results.crate_info.link_args;
|
||
|
||
if crate_type == config::CrateType::Executable {
|
||
let mut position_independent_executable = false;
|
||
|
||
if t.options.position_independent_executables {
|
||
let empty_vec = Vec::new();
|
||
let args = sess.opts.cg.link_args.as_ref().unwrap_or(&empty_vec);
|
||
let more_args = &sess.opts.cg.link_arg;
|
||
let mut args = args.iter().chain(more_args.iter()).chain(used_link_args.iter());
|
||
|
||
if is_pic(sess) && !sess.crt_static(Some(crate_type)) && !args.any(|x| *x == "-static")
|
||
{
|
||
position_independent_executable = true;
|
||
}
|
||
}
|
||
|
||
if position_independent_executable {
|
||
cmd.position_independent_executable();
|
||
} else {
|
||
// recent versions of gcc can be configured to generate position
|
||
// independent executables by default. We have to pass -no-pie to
|
||
// explicitly turn that off. Not applicable to ld.
|
||
if sess.target.target.options.linker_is_gnu && flavor != LinkerFlavor::Ld {
|
||
cmd.no_position_independent_executable();
|
||
}
|
||
}
|
||
}
|
||
|
||
let relro_level = match sess.opts.debugging_opts.relro_level {
|
||
Some(level) => level,
|
||
None => t.options.relro_level,
|
||
};
|
||
match relro_level {
|
||
RelroLevel::Full => {
|
||
cmd.full_relro();
|
||
}
|
||
RelroLevel::Partial => {
|
||
cmd.partial_relro();
|
||
}
|
||
RelroLevel::Off => {
|
||
cmd.no_relro();
|
||
}
|
||
RelroLevel::None => {}
|
||
}
|
||
|
||
// Pass optimization flags down to the linker.
|
||
cmd.optimize();
|
||
|
||
// Pass debuginfo flags down to the linker.
|
||
cmd.debuginfo();
|
||
|
||
// We want to, by default, prevent the compiler from accidentally leaking in
|
||
// any system libraries, so we may explicitly ask linkers to not link to any
|
||
// libraries by default. Note that this does not happen for windows because
|
||
// windows pulls in some large number of libraries and I couldn't quite
|
||
// figure out which subset we wanted.
|
||
//
|
||
// This is all naturally configurable via the standard methods as well.
|
||
if !sess.opts.cg.default_linker_libraries.unwrap_or(false) && t.options.no_default_libraries {
|
||
cmd.no_default_libraries();
|
||
}
|
||
|
||
// Take careful note of the ordering of the arguments we pass to the linker
|
||
// here. Linkers will assume that things on the left depend on things to the
|
||
// right. Things on the right cannot depend on things on the left. This is
|
||
// all formally implemented in terms of resolving symbols (libs on the right
|
||
// resolve unknown symbols of libs on the left, but not vice versa).
|
||
//
|
||
// For this reason, we have organized the arguments we pass to the linker as
|
||
// such:
|
||
//
|
||
// 1. The local object that LLVM just generated
|
||
// 2. Local native libraries
|
||
// 3. Upstream rust libraries
|
||
// 4. Upstream native libraries
|
||
//
|
||
// The rationale behind this ordering is that those items lower down in the
|
||
// list can't depend on items higher up in the list. For example nothing can
|
||
// depend on what we just generated (e.g., that'd be a circular dependency).
|
||
// Upstream rust libraries are not allowed to depend on our local native
|
||
// libraries as that would violate the structure of the DAG, in that
|
||
// scenario they are required to link to them as well in a shared fashion.
|
||
//
|
||
// Note that upstream rust libraries may contain native dependencies as
|
||
// well, but they also can't depend on what we just started to add to the
|
||
// link line. And finally upstream native libraries can't depend on anything
|
||
// in this DAG so far because they're only dylibs and dylibs can only depend
|
||
// on other dylibs (e.g., other native deps).
|
||
add_local_native_libraries(cmd, sess, codegen_results);
|
||
add_upstream_rust_crates::<B>(cmd, sess, codegen_results, crate_type, tmpdir);
|
||
add_upstream_native_libraries(cmd, sess, codegen_results, crate_type);
|
||
|
||
// Tell the linker what we're doing.
|
||
if crate_type != config::CrateType::Executable {
|
||
cmd.build_dylib(out_filename);
|
||
}
|
||
if crate_type == config::CrateType::Executable && sess.crt_static(Some(crate_type)) {
|
||
cmd.build_static_executable();
|
||
}
|
||
|
||
if sess.opts.cg.profile_generate.enabled() {
|
||
cmd.pgo_gen();
|
||
}
|
||
|
||
if sess.opts.debugging_opts.control_flow_guard != CFGuard::Disabled {
|
||
cmd.control_flow_guard();
|
||
}
|
||
|
||
// FIXME (#2397): At some point we want to rpath our guesses as to
|
||
// where extern libraries might live, based on the
|
||
// addl_lib_search_paths
|
||
if sess.opts.cg.rpath {
|
||
let target_triple = sess.opts.target_triple.triple();
|
||
let mut get_install_prefix_lib_path = || {
|
||
let install_prefix = option_env!("CFG_PREFIX").expect("CFG_PREFIX");
|
||
let tlib = filesearch::relative_target_lib_path(&sess.sysroot, target_triple);
|
||
let mut path = PathBuf::from(install_prefix);
|
||
path.push(&tlib);
|
||
|
||
path
|
||
};
|
||
let mut rpath_config = RPathConfig {
|
||
used_crates: &codegen_results.crate_info.used_crates_dynamic,
|
||
out_filename: out_filename.to_path_buf(),
|
||
has_rpath: sess.target.target.options.has_rpath,
|
||
is_like_osx: sess.target.target.options.is_like_osx,
|
||
linker_is_gnu: sess.target.target.options.linker_is_gnu,
|
||
get_install_prefix_lib_path: &mut get_install_prefix_lib_path,
|
||
};
|
||
cmd.args(&rpath::get_rpath_flags(&mut rpath_config));
|
||
}
|
||
|
||
// Finally add all the linker arguments provided on the command line along
|
||
// with any #[link_args] attributes found inside the crate
|
||
if let Some(ref args) = sess.opts.cg.link_args {
|
||
cmd.args(args);
|
||
}
|
||
cmd.args(&sess.opts.cg.link_arg);
|
||
cmd.args(&used_link_args);
|
||
}
|
||
|
||
// # Native library linking
|
||
//
|
||
// User-supplied library search paths (-L on the command line). These are
|
||
// the same paths used to find Rust crates, so some of them may have been
|
||
// added already by the previous crate linking code. This only allows them
|
||
// to be found at compile time so it is still entirely up to outside
|
||
// forces to make sure that library can be found at runtime.
|
||
//
|
||
// Also note that the native libraries linked here are only the ones located
|
||
// in the current crate. Upstream crates with native library dependencies
|
||
// may have their native library pulled in above.
|
||
pub fn add_local_native_libraries(
|
||
cmd: &mut dyn Linker,
|
||
sess: &Session,
|
||
codegen_results: &CodegenResults,
|
||
) {
|
||
let filesearch = sess.target_filesearch(PathKind::All);
|
||
for search_path in filesearch.search_paths() {
|
||
match search_path.kind {
|
||
PathKind::Framework => {
|
||
cmd.framework_path(&search_path.dir);
|
||
}
|
||
_ => {
|
||
cmd.include_path(&fix_windows_verbatim_for_gcc(&search_path.dir));
|
||
}
|
||
}
|
||
}
|
||
|
||
let relevant_libs =
|
||
codegen_results.crate_info.used_libraries.iter().filter(|l| relevant_lib(sess, l));
|
||
|
||
let search_path = archive_search_paths(sess);
|
||
for lib in relevant_libs {
|
||
let name = match lib.name {
|
||
Some(l) => l,
|
||
None => continue,
|
||
};
|
||
match lib.kind {
|
||
NativeLibraryKind::NativeUnknown => cmd.link_dylib(name),
|
||
NativeLibraryKind::NativeFramework => cmd.link_framework(name),
|
||
NativeLibraryKind::NativeStaticNobundle => cmd.link_staticlib(name),
|
||
NativeLibraryKind::NativeStatic => cmd.link_whole_staticlib(name, &search_path),
|
||
NativeLibraryKind::NativeRawDylib => {
|
||
// FIXME(#58713): Proper handling for raw dylibs.
|
||
bug!("raw_dylib feature not yet implemented");
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// # Rust Crate linking
|
||
//
|
||
// Rust crates are not considered at all when creating an rlib output. All
|
||
// dependencies will be linked when producing the final output (instead of
|
||
// the intermediate rlib version)
|
||
fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
|
||
cmd: &mut dyn Linker,
|
||
sess: &'a Session,
|
||
codegen_results: &CodegenResults,
|
||
crate_type: config::CrateType,
|
||
tmpdir: &Path,
|
||
) {
|
||
// All of the heavy lifting has previously been accomplished by the
|
||
// dependency_format module of the compiler. This is just crawling the
|
||
// output of that module, adding crates as necessary.
|
||
//
|
||
// Linking to a rlib involves just passing it to the linker (the linker
|
||
// will slurp up the object files inside), and linking to a dynamic library
|
||
// involves just passing the right -l flag.
|
||
|
||
let (_, data) = codegen_results
|
||
.crate_info
|
||
.dependency_formats
|
||
.iter()
|
||
.find(|(ty, _)| *ty == crate_type)
|
||
.expect("failed to find crate type in dependency format list");
|
||
|
||
// Invoke get_used_crates to ensure that we get a topological sorting of
|
||
// crates.
|
||
let deps = &codegen_results.crate_info.used_crates_dynamic;
|
||
|
||
// There's a few internal crates in the standard library (aka libcore and
|
||
// libstd) which actually have a circular dependence upon one another. This
|
||
// currently arises through "weak lang items" where libcore requires things
|
||
// like `rust_begin_unwind` but libstd ends up defining it. To get this
|
||
// circular dependence to work correctly in all situations we'll need to be
|
||
// sure to correctly apply the `--start-group` and `--end-group` options to
|
||
// GNU linkers, otherwise if we don't use any other symbol from the standard
|
||
// library it'll get discarded and the whole application won't link.
|
||
//
|
||
// In this loop we're calculating the `group_end`, after which crate to
|
||
// pass `--end-group` and `group_start`, before which crate to pass
|
||
// `--start-group`. We currently do this by passing `--end-group` after
|
||
// the first crate (when iterating backwards) that requires a lang item
|
||
// defined somewhere else. Once that's set then when we've defined all the
|
||
// necessary lang items we'll pass `--start-group`.
|
||
//
|
||
// Note that this isn't amazing logic for now but it should do the trick
|
||
// for the current implementation of the standard library.
|
||
let mut group_end = None;
|
||
let mut group_start = None;
|
||
// Crates available for linking thus far.
|
||
let mut available = FxHashSet::default();
|
||
// Crates required to satisfy dependencies discovered so far.
|
||
let mut required = FxHashSet::default();
|
||
|
||
let info = &codegen_results.crate_info;
|
||
for &(cnum, _) in deps.iter().rev() {
|
||
if let Some(missing) = info.missing_lang_items.get(&cnum) {
|
||
let missing_crates = missing.iter().map(|i| info.lang_item_to_crate.get(i).copied());
|
||
required.extend(missing_crates);
|
||
}
|
||
|
||
required.insert(Some(cnum));
|
||
available.insert(Some(cnum));
|
||
|
||
if required.len() > available.len() && group_end.is_none() {
|
||
group_end = Some(cnum);
|
||
}
|
||
if required.len() == available.len() && group_end.is_some() {
|
||
group_start = Some(cnum);
|
||
break;
|
||
}
|
||
}
|
||
|
||
// If we didn't end up filling in all lang items from upstream crates then
|
||
// we'll be filling it in with our crate. This probably means we're the
|
||
// standard library itself, so skip this for now.
|
||
if group_end.is_some() && group_start.is_none() {
|
||
group_end = None;
|
||
}
|
||
|
||
let mut compiler_builtins = None;
|
||
|
||
for &(cnum, _) in deps.iter() {
|
||
if group_start == Some(cnum) {
|
||
cmd.group_start();
|
||
}
|
||
|
||
// We may not pass all crates through to the linker. Some crates may
|
||
// appear statically in an existing dylib, meaning we'll pick up all the
|
||
// symbols from the dylib.
|
||
let src = &codegen_results.crate_info.used_crate_source[&cnum];
|
||
match data[cnum.as_usize() - 1] {
|
||
_ if codegen_results.crate_info.profiler_runtime == Some(cnum) => {
|
||
add_static_crate::<B>(cmd, sess, codegen_results, tmpdir, crate_type, cnum);
|
||
}
|
||
// compiler-builtins are always placed last to ensure that they're
|
||
// linked correctly.
|
||
_ if codegen_results.crate_info.compiler_builtins == Some(cnum) => {
|
||
assert!(compiler_builtins.is_none());
|
||
compiler_builtins = Some(cnum);
|
||
}
|
||
Linkage::NotLinked | Linkage::IncludedFromDylib => {}
|
||
Linkage::Static => {
|
||
add_static_crate::<B>(cmd, sess, codegen_results, tmpdir, crate_type, cnum);
|
||
}
|
||
Linkage::Dynamic => add_dynamic_crate(cmd, sess, &src.dylib.as_ref().unwrap().0),
|
||
}
|
||
|
||
if group_end == Some(cnum) {
|
||
cmd.group_end();
|
||
}
|
||
}
|
||
|
||
// compiler-builtins are always placed last to ensure that they're
|
||
// linked correctly.
|
||
// We must always link the `compiler_builtins` crate statically. Even if it
|
||
// was already "included" in a dylib (e.g., `libstd` when `-C prefer-dynamic`
|
||
// is used)
|
||
if let Some(cnum) = compiler_builtins {
|
||
add_static_crate::<B>(cmd, sess, codegen_results, tmpdir, crate_type, cnum);
|
||
}
|
||
|
||
// Converts a library file-stem into a cc -l argument
|
||
fn unlib<'a>(config: &config::Config, stem: &'a str) -> &'a str {
|
||
if stem.starts_with("lib") && !config.target.options.is_like_windows {
|
||
&stem[3..]
|
||
} else {
|
||
stem
|
||
}
|
||
}
|
||
|
||
// Adds the static "rlib" versions of all crates to the command line.
|
||
// There's a bit of magic which happens here specifically related to LTO and
|
||
// dynamic libraries. Specifically:
|
||
//
|
||
// * For LTO, we remove upstream object files.
|
||
// * For dylibs we remove metadata and bytecode from upstream rlibs
|
||
//
|
||
// When performing LTO, almost(*) all of the bytecode from the upstream
|
||
// libraries has already been included in our object file output. As a
|
||
// result we need to remove the object files in the upstream libraries so
|
||
// the linker doesn't try to include them twice (or whine about duplicate
|
||
// symbols). We must continue to include the rest of the rlib, however, as
|
||
// it may contain static native libraries which must be linked in.
|
||
//
|
||
// (*) Crates marked with `#![no_builtins]` don't participate in LTO and
|
||
// their bytecode wasn't included. The object files in those libraries must
|
||
// still be passed to the linker.
|
||
//
|
||
// When making a dynamic library, linkers by default don't include any
|
||
// object files in an archive if they're not necessary to resolve the link.
|
||
// We basically want to convert the archive (rlib) to a dylib, though, so we
|
||
// *do* want everything included in the output, regardless of whether the
|
||
// linker thinks it's needed or not. As a result we must use the
|
||
// --whole-archive option (or the platform equivalent). When using this
|
||
// option the linker will fail if there are non-objects in the archive (such
|
||
// as our own metadata and/or bytecode). All in all, for rlibs to be
|
||
// entirely included in dylibs, we need to remove all non-object files.
|
||
//
|
||
// Note, however, that if we're not doing LTO or we're not producing a dylib
|
||
// (aka we're making an executable), we can just pass the rlib blindly to
|
||
// the linker (fast) because it's fine if it's not actually included as
|
||
// we're at the end of the dependency chain.
|
||
fn add_static_crate<'a, B: ArchiveBuilder<'a>>(
|
||
cmd: &mut dyn Linker,
|
||
sess: &'a Session,
|
||
codegen_results: &CodegenResults,
|
||
tmpdir: &Path,
|
||
crate_type: config::CrateType,
|
||
cnum: CrateNum,
|
||
) {
|
||
let src = &codegen_results.crate_info.used_crate_source[&cnum];
|
||
let cratepath = &src.rlib.as_ref().unwrap().0;
|
||
|
||
// See the comment above in `link_staticlib` and `link_rlib` for why if
|
||
// there's a static library that's not relevant we skip all object
|
||
// files.
|
||
let native_libs = &codegen_results.crate_info.native_libraries[&cnum];
|
||
let skip_native = native_libs
|
||
.iter()
|
||
.any(|lib| lib.kind == NativeLibraryKind::NativeStatic && !relevant_lib(sess, lib));
|
||
|
||
if (!are_upstream_rust_objects_already_included(sess)
|
||
|| ignored_for_lto(sess, &codegen_results.crate_info, cnum))
|
||
&& crate_type != config::CrateType::Dylib
|
||
&& !skip_native
|
||
{
|
||
cmd.link_rlib(&fix_windows_verbatim_for_gcc(cratepath));
|
||
return;
|
||
}
|
||
|
||
let dst = tmpdir.join(cratepath.file_name().unwrap());
|
||
let name = cratepath.file_name().unwrap().to_str().unwrap();
|
||
let name = &name[3..name.len() - 5]; // chop off lib/.rlib
|
||
|
||
sess.prof.generic_activity_with_arg("link_altering_rlib", name).run(|| {
|
||
let mut archive = <B as ArchiveBuilder>::new(sess, &dst, Some(cratepath));
|
||
archive.update_symbols();
|
||
|
||
let mut any_objects = false;
|
||
for f in archive.src_files() {
|
||
if f.ends_with(RLIB_BYTECODE_EXTENSION) || f == METADATA_FILENAME {
|
||
archive.remove_file(&f);
|
||
continue;
|
||
}
|
||
|
||
let canonical = f.replace("-", "_");
|
||
let canonical_name = name.replace("-", "_");
|
||
|
||
let is_rust_object =
|
||
canonical.starts_with(&canonical_name) && looks_like_rust_object_file(&f);
|
||
|
||
// If we've been requested to skip all native object files
|
||
// (those not generated by the rust compiler) then we can skip
|
||
// this file. See above for why we may want to do this.
|
||
let skip_because_cfg_say_so = skip_native && !is_rust_object;
|
||
|
||
// If we're performing LTO and this is a rust-generated object
|
||
// file, then we don't need the object file as it's part of the
|
||
// LTO module. Note that `#![no_builtins]` is excluded from LTO,
|
||
// though, so we let that object file slide.
|
||
let skip_because_lto = are_upstream_rust_objects_already_included(sess)
|
||
&& is_rust_object
|
||
&& (sess.target.target.options.no_builtins
|
||
|| !codegen_results.crate_info.is_no_builtins.contains(&cnum));
|
||
|
||
if skip_because_cfg_say_so || skip_because_lto {
|
||
archive.remove_file(&f);
|
||
} else {
|
||
any_objects = true;
|
||
}
|
||
}
|
||
|
||
if !any_objects {
|
||
return;
|
||
}
|
||
archive.build();
|
||
|
||
// If we're creating a dylib, then we need to include the
|
||
// whole of each object in our archive into that artifact. This is
|
||
// because a `dylib` can be reused as an intermediate artifact.
|
||
//
|
||
// Note, though, that we don't want to include the whole of a
|
||
// compiler-builtins crate (e.g., compiler-rt) because it'll get
|
||
// repeatedly linked anyway.
|
||
if crate_type == config::CrateType::Dylib
|
||
&& codegen_results.crate_info.compiler_builtins != Some(cnum)
|
||
{
|
||
cmd.link_whole_rlib(&fix_windows_verbatim_for_gcc(&dst));
|
||
} else {
|
||
cmd.link_rlib(&fix_windows_verbatim_for_gcc(&dst));
|
||
}
|
||
});
|
||
}
|
||
|
||
// Same thing as above, but for dynamic crates instead of static crates.
|
||
fn add_dynamic_crate(cmd: &mut dyn Linker, sess: &Session, cratepath: &Path) {
|
||
// Just need to tell the linker about where the library lives and
|
||
// what its name is
|
||
let parent = cratepath.parent();
|
||
if let Some(dir) = parent {
|
||
cmd.include_path(&fix_windows_verbatim_for_gcc(dir));
|
||
}
|
||
let filestem = cratepath.file_stem().unwrap().to_str().unwrap();
|
||
cmd.link_rust_dylib(
|
||
Symbol::intern(&unlib(&sess.target, filestem)),
|
||
parent.unwrap_or(Path::new("")),
|
||
);
|
||
}
|
||
}
|
||
|
||
// Link in all of our upstream crates' native dependencies. Remember that
|
||
// all of these upstream native dependencies are all non-static
|
||
// dependencies. We've got two cases then:
|
||
//
|
||
// 1. The upstream crate is an rlib. In this case we *must* link in the
|
||
// native dependency because the rlib is just an archive.
|
||
//
|
||
// 2. The upstream crate is a dylib. In order to use the dylib, we have to
|
||
// have the dependency present on the system somewhere. Thus, we don't
|
||
// gain a whole lot from not linking in the dynamic dependency to this
|
||
// crate as well.
|
||
//
|
||
// The use case for this is a little subtle. In theory the native
|
||
// dependencies of a crate are purely an implementation detail of the crate
|
||
// itself, but the problem arises with generic and inlined functions. If a
|
||
// generic function calls a native function, then the generic function must
|
||
// be instantiated in the target crate, meaning that the native symbol must
|
||
// also be resolved in the target crate.
|
||
pub fn add_upstream_native_libraries(
|
||
cmd: &mut dyn Linker,
|
||
sess: &Session,
|
||
codegen_results: &CodegenResults,
|
||
crate_type: config::CrateType,
|
||
) {
|
||
// Be sure to use a topological sorting of crates because there may be
|
||
// interdependencies between native libraries. When passing -nodefaultlibs,
|
||
// for example, almost all native libraries depend on libc, so we have to
|
||
// make sure that's all the way at the right (liblibc is near the base of
|
||
// the dependency chain).
|
||
//
|
||
// This passes RequireStatic, but the actual requirement doesn't matter,
|
||
// we're just getting an ordering of crate numbers, we're not worried about
|
||
// the paths.
|
||
let (_, data) = codegen_results
|
||
.crate_info
|
||
.dependency_formats
|
||
.iter()
|
||
.find(|(ty, _)| *ty == crate_type)
|
||
.expect("failed to find crate type in dependency format list");
|
||
|
||
let crates = &codegen_results.crate_info.used_crates_static;
|
||
for &(cnum, _) in crates {
|
||
for lib in codegen_results.crate_info.native_libraries[&cnum].iter() {
|
||
let name = match lib.name {
|
||
Some(l) => l,
|
||
None => continue,
|
||
};
|
||
if !relevant_lib(sess, &lib) {
|
||
continue;
|
||
}
|
||
match lib.kind {
|
||
NativeLibraryKind::NativeUnknown => cmd.link_dylib(name),
|
||
NativeLibraryKind::NativeFramework => cmd.link_framework(name),
|
||
NativeLibraryKind::NativeStaticNobundle => {
|
||
// Link "static-nobundle" native libs only if the crate they originate from
|
||
// is being linked statically to the current crate. If it's linked dynamically
|
||
// or is an rlib already included via some other dylib crate, the symbols from
|
||
// native libs will have already been included in that dylib.
|
||
if data[cnum.as_usize() - 1] == Linkage::Static {
|
||
cmd.link_staticlib(name)
|
||
}
|
||
}
|
||
// ignore statically included native libraries here as we've
|
||
// already included them when we included the rust library
|
||
// previously
|
||
NativeLibraryKind::NativeStatic => {}
|
||
NativeLibraryKind::NativeRawDylib => {
|
||
// FIXME(#58713): Proper handling for raw dylibs.
|
||
bug!("raw_dylib feature not yet implemented");
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
pub fn relevant_lib(sess: &Session, lib: &NativeLibrary) -> bool {
|
||
match lib.cfg {
|
||
Some(ref cfg) => rustc_attr::cfg_matches(cfg, &sess.parse_sess, None),
|
||
None => true,
|
||
}
|
||
}
|
||
|
||
pub fn are_upstream_rust_objects_already_included(sess: &Session) -> bool {
|
||
match sess.lto() {
|
||
config::Lto::Fat => true,
|
||
config::Lto::Thin => {
|
||
// If we defer LTO to the linker, we haven't run LTO ourselves, so
|
||
// any upstream object files have not been copied yet.
|
||
!sess.opts.cg.linker_plugin_lto.enabled()
|
||
}
|
||
config::Lto::No | config::Lto::ThinLocal => false,
|
||
}
|
||
}
|
||
|
||
fn is_pic(sess: &Session) -> bool {
|
||
let reloc_model_arg = match sess.opts.cg.relocation_model {
|
||
Some(ref s) => &s[..],
|
||
None => &sess.target.target.options.relocation_model[..],
|
||
};
|
||
|
||
reloc_model_arg == "pic"
|
||
}
|