Merge pull request #495 from bjorn3/use_cg_clif_link

Use cg clif link

Cargo.lock

@@ -19,7 +19,7 @@ dependencies = [
 [[package]]
 name = "ar"
 version = "0.6.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+source = "git+https://github.com/bjorn3/rust-ar.git?branch=non_multiple_of_two_identifiers_gnu_format#efa2308b9ded41f4977d4fed98dac7af4d9075cf"
 dependencies = [
  "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -582,7 +582,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "rustc_codegen_cranelift"
 version = "0.1.0"
 dependencies = [
- "ar 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ar 0.6.2 (git+https://github.com/bjorn3/rust-ar.git?branch=non_multiple_of_two_identifiers_gnu_format)",
  "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "cranelift 0.30.0 (git+https://github.com/CraneStation/cranelift.git)",
@@ -843,7 +843,7 @@ dependencies = [
 [metadata]
 "checksum aho-corasick 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e6f484ae0c99fec2e858eb6134949117399f222608d84cadb3f58c1f97c2364c"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
-"checksum ar 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "579681b3fecd1e9d6b5ce6969e05f9feb913f296eddaf595be1166a5ca597bc4"
+"checksum ar 0.6.2 (git+https://github.com/bjorn3/rust-ar.git?branch=non_multiple_of_two_identifiers_gnu_format)" = "<none>"
 "checksum arrayvec 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "92c7fb76bc8826a8b33b4ee5bb07a247a81e76764ab4d55e8f73e3a4d8808c71"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 "checksum autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a6d640bee2da49f60a4068a7fae53acde8982514ab7bae8b8cea9e88cbcfd799"

Cargo.toml

@@ -38,5 +38,8 @@ indexmap = "1.0.2"
 #[patch."https://github.com/gimli-rs/gimli.git"]
 #gimli = { path = "../" }
 
+[patch.crates-io]
+ar = { git = "https://github.com/bjorn3/rust-ar.git", branch = "non_multiple_of_two_identifiers_gnu_format" }
+
 [profile.dev.overrides."*"]
 opt-level = 3

build_sysroot/Cargo.toml

@@ -13,6 +13,7 @@ alloc_system = { path = "./alloc_system" }
 
 [patch.crates-io]
 rustc-std-workspace-core = { path = "./sysroot_src/src/tools/rustc-std-workspace-core" }
+rustc-std-workspace-alloc = { path = "./rustc-std-workspace-alloc" }
 compiler_builtins = { path = "./compiler_builtins" }
 
 [profile.release]

build_sysroot/rustc-std-workspace-alloc/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "rustc-std-workspace-alloc"
+version = "1.0.0"
+authors = ["Alex Crichton <alex@alexcrichton.com>"]
+license = 'MIT/Apache-2.0'
+description = """
+Hack for the compiler's own build system
+"""
+edition = "2018"
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+alloc = { path = "../sysroot_src/src/liballoc" }

build_sysroot/rustc-std-workspace-alloc/lib.rs

@@ -0,0 +1,5 @@
+#![feature(no_core)]
+#![no_core]
+#![deny(rust_2018_idioms)]
+
+pub use ::alloc::*;

example/alloc_example.rs

@@ -1,4 +1,4 @@
-#![feature(start, box_syntax, alloc_system, core_intrinsics, alloc, alloc_prelude, alloc_error_handler)]
+#![feature(start, box_syntax, alloc_system, core_intrinsics, alloc_prelude, alloc_error_handler)]
 #![no_std]
 
 extern crate alloc;

src/archive.rs

@@ -1,4 +1,3 @@
-use std::collections::HashMap;
 use std::fs::File;
 use std::path::{Path, PathBuf};
 
@@ -8,12 +7,14 @@ use rustc_codegen_ssa::{METADATA_FILENAME, RLIB_BYTECODE_EXTENSION};
 use rustc_codegen_ssa::back::archive::{ArchiveBuilder, find_library};
 
 struct ArchiveConfig<'a> {
-    pub sess: &'a Session,
+    sess: &'a Session,
-    pub dst: PathBuf,
+    dst: PathBuf,
-    pub src: Option<PathBuf>,
+    src: Option<PathBuf>,
-    pub lib_search_paths: Vec<PathBuf>,
+    lib_search_paths: Vec<PathBuf>,
+    use_gnu_style_archive: bool,
 }
 
+#[derive(Debug)]
 enum ArchiveEntry {
     FromArchive { archive_index: usize, entry_index: usize },
     File(File),
@@ -22,7 +23,9 @@ enum ArchiveEntry {
 pub struct ArArchiveBuilder<'a> {
     config: ArchiveConfig<'a>,
     src_archives: Vec<ar::Archive<File>>,
-    entries: HashMap<String, ArchiveEntry>,
+    // Don't use `HashMap` here, as the order is important. `rust.metadata.bin` must always be at
+    // the end of an archive for linkers to not get confused.
+    entries: Vec<(String, ArchiveEntry)>,
     update_symbols: bool,
 }
 
@@ -34,25 +37,27 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
             dst: output.to_path_buf(),
             src: input.map(|p| p.to_path_buf()),
             lib_search_paths: archive_search_paths(sess),
+            // FIXME test for linux and System V derivatives instead
+            use_gnu_style_archive: !sess.target.target.options.is_like_osx,
         };
 
         let (src_archives, entries) = if let Some(src) = &config.src {
             let mut archive = ar::Archive::new(File::open(src).unwrap());
-            let mut entries = HashMap::new();
+            let mut entries = Vec::new();
 
             let mut i = 0;
             while let Some(entry) = archive.next_entry() {
                 let entry = entry.unwrap();
-                entries.insert(
+                entries.push((
                     String::from_utf8(entry.header().identifier().to_vec()).unwrap(),
                     ArchiveEntry::FromArchive { archive_index: 0, entry_index: i },
-                );
+                ));
                 i += 1;
             }
 
             (vec![archive], entries)
         } else {
-            (vec![], HashMap::new())
+            (vec![], Vec::new())
         };
 
         ArArchiveBuilder {
@@ -64,22 +69,22 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
     }
 
     fn src_files(&mut self) -> Vec<String> {
-        self.entries.keys().cloned().collect()
+        self.entries.iter().map(|(name, _)| name.clone()).collect()
     }
 
     fn remove_file(&mut self, name: &str) {
-        let file = self.entries.remove(name);
+        let index = self.entries
-        assert!(
+            .iter()
-            file.is_some(),
+            .position(|(entry_name, _)| entry_name == name)
-            "Tried to remove file not existing in src archive",
+            .expect("Tried to remove file not existing in src archive");
-        );
+        self.entries.remove(index);
     }
 
     fn add_file(&mut self, file: &Path) {
-        self.entries.insert(
+        self.entries.push((
             file.file_name().unwrap().to_str().unwrap().to_string(),
             ArchiveEntry::File(File::open(file).unwrap()),
-        );
+        ));
     }
 
     fn add_native_library(&mut self, name: &str) {
@@ -119,7 +124,20 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
     }
 
     fn build(mut self) {
-        let mut builder = ar::Builder::new(File::create(&self.config.dst).unwrap());
+        enum BuilderKind {
+            Bsd(ar::Builder<File>),
+            Gnu(ar::GnuBuilder<File>),
+        }
+
+        let archive_file = File::create(&self.config.dst).unwrap();
+        let mut builder = if self.config.use_gnu_style_archive {
+            BuilderKind::Gnu(ar::GnuBuilder::new(
+                archive_file,
+                self.entries.iter().map(|(name, _)| name.as_bytes().to_vec()).collect(),
+            ))
+        } else {
+            BuilderKind::Bsd(ar::Builder::new(archive_file))
+        };
 
         // Add all files
         for (entry_name, entry) in self.entries.into_iter() {
@@ -127,16 +145,23 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
                 ArchiveEntry::FromArchive { archive_index, entry_index } => {
                     let entry = self.src_archives[archive_index].jump_to_entry(entry_index).unwrap();
                     let orig_header = entry.header();
+
                     let mut header =
                         ar::Header::new(orig_header.identifier().to_vec(), orig_header.size());
                     header.set_mtime(orig_header.mtime());
                     header.set_uid(orig_header.uid());
                     header.set_gid(orig_header.gid());
                     header.set_mode(orig_header.mode());
-                    builder.append(&header, entry).unwrap();
+                    match builder {
+                        BuilderKind::Bsd(ref mut builder) => builder.append(&header, entry).unwrap(),
+                        BuilderKind::Gnu(ref mut builder) => builder.append(&header, entry).unwrap(),
+                    }
                 }
                 ArchiveEntry::File(mut file) => {
-                    builder.append_file(entry_name.as_bytes(), &mut file).unwrap();
+                    match builder {
+                        BuilderKind::Bsd(ref mut builder) => builder.append_file(entry_name.as_bytes(), &mut file).unwrap(),
+                        BuilderKind::Gnu(ref mut builder) => builder.append_file(entry_name.as_bytes(), &mut file).unwrap(),
+                    }
                 }
             }
         }
@@ -169,10 +194,10 @@ impl<'a> ArArchiveBuilder<'a> {
             let entry = entry.unwrap();
             let file_name = String::from_utf8(entry.header().identifier().to_vec()).unwrap();
             if !skip(&file_name) {
-                self.entries.insert(
+                self.entries.push((
                     file_name,
                     ArchiveEntry::FromArchive { archive_index, entry_index: i },
-                );
+                ));
             }
             i += 1;
         }

src/lib.rs

@@ -28,7 +28,6 @@ use rustc::util::common::ErrorReported;
 use rustc_codegen_ssa::back::linker::LinkerInfo;
 use rustc_codegen_ssa::CrateInfo;
 use rustc_codegen_utils::codegen_backend::CodegenBackend;
-use rustc_codegen_utils::link::out_filename;
 use rustc_mir::monomorphize::partitioning::CodegenUnitExt;
 
 use cranelift::codegen::settings;
@@ -46,8 +45,6 @@ mod common;
 mod constant;
 mod debuginfo;
 mod intrinsics;
-mod link;
-mod link_copied;
 mod linkage;
 mod main_shim;
 mod metadata;
@@ -343,13 +340,13 @@ impl CodegenBackend for CraneliftCodegenBackend {
                 } else {
                     None
                 },
-                metadata_module: CompiledModule {
+                metadata_module: Some(CompiledModule {
                     name: "dummy_metadata".to_string(),
                     kind: ModuleKind::Metadata,
                     object: None,
                     bytecode: None,
                     bytecode_compressed: None,
-                },
+                }),
                 crate_hash: tcx.crate_hash(LOCAL_CRATE),
                 metadata,
                 windows_subsystem: None, // Windows is not yet supported
@@ -366,20 +363,21 @@ impl CodegenBackend for CraneliftCodegenBackend {
         _dep_graph: &DepGraph,
         outputs: &OutputFilenames,
     ) -> Result<(), ErrorReported> {
-        let res = *res
+        use rustc_codegen_ssa::back::link::link_binary;
+
+        let codegen_results = *res
             .downcast::<CodegenResults>()
             .expect("Expected CraneliftCodegenBackend's CodegenResult, found Box<Any>");
 
-        for &crate_type in sess.crate_types.borrow().iter() {
+        let target_cpu = ::target_lexicon::HOST.to_string();
-            let output_name = out_filename(sess, crate_type, &outputs, &res.crate_name.as_str());
+        link_binary::<crate::archive::ArArchiveBuilder<'_>>(
-            match crate_type {
+            sess,
-                CrateType::Rlib => link::link_rlib(sess, &res, output_name),
+            &codegen_results,
-                CrateType::Dylib | CrateType::Executable => {
+            outputs,
-                    link::link_natively(sess, crate_type, &res, &output_name);
+            &codegen_results.crate_name.as_str(),
-                }
+            &target_cpu,
-                _ => sess.fatal(&format!("Unsupported crate type: {:?}", crate_type)),
+        );
-            }
+
-        }
         Ok(())
     }
 }

src/link.rs

@@ -1,463 +0,0 @@
-use std::ascii;
-use std::char;
-use std::env;
-use std::fs::File;
-use std::io;
-use std::path::{Path, PathBuf};
-use std::str;
-
-use tempfile::Builder as TempFileBuilder;
-
-use rustc::session::config::{self, CrateType, DebugInfo, RUST_CGU_EXT};
-use rustc::session::search_paths::PathKind;
-use rustc::session::Session;
-use rustc_codegen_ssa::METADATA_FILENAME;
-use rustc_codegen_ssa::back::command::Command;
-use rustc_codegen_ssa::back::link::*;
-use rustc_codegen_ssa::back::linker::*;
-use rustc_fs_util::fix_windows_verbatim_for_gcc;
-use rustc_target::spec::{LinkerFlavor, PanicStrategy, RelroLevel};
-
-use crate::prelude::*;
-
-use crate::link_copied::*;
-
-pub(crate) fn link_rlib(sess: &Session, res: &CodegenResults, output_name: PathBuf) {
-    let file = File::create(&output_name).unwrap();
-    let mut builder = ar::Builder::new(file);
-
-    // Add main object file
-    for module in &res.modules {
-        if let Some(ref object_path) = module.object {
-            let object = File::open(object_path).expect("Someone deleted our object file");
-            let object_len = object.metadata().unwrap().len();
-            builder
-                .append(
-                    &ar::Header::new(
-                        (module.name.to_string() + RUST_CGU_EXT).into_bytes(),
-                        object_len,
-                    ),
-                    object,
-                )
-                .unwrap();
-        }
-    }
-
-    // Non object files need to be added after object files, because ranlib will
-    // try to read the native architecture from the first file, even if it isn't
-    // an object file
-    builder
-        .append(
-            &ar::Header::new(
-                METADATA_FILENAME.as_bytes().to_vec(),
-                res.metadata.raw_data.len() as u64,
-            ),
-            ::std::io::Cursor::new(res.metadata.raw_data.clone()),
-        )
-        .unwrap();
-
-    // Finalize archive
-    std::mem::drop(builder);
-
-    // Run ranlib to be able to link the archive
-    let status = std::process::Command::new("ranlib")
-        .arg(output_name)
-        .status()
-        .expect("Couldn't run ranlib");
-    if !status.success() {
-        sess.fatal(&format!("Ranlib exited with code {:?}", status.code()));
-    }
-}
-
-pub(crate) fn link_natively(
-    sess: &Session,
-    crate_type: CrateType,
-    codegen_results: &CodegenResults,
-    out_filename: &Path,
-) {
-    let tmpdir = match TempFileBuilder::new().prefix("rustc").tempdir() {
-        Ok(tmpdir) => tmpdir,
-        Err(err) => sess.fatal(&format!("couldn't create a temp dir: {}", err)),
-    };
-
-    let (linker, flavor) = linker_and_flavor(sess);
-
-    // The invocations of cc share some flags across platforms
-    let (pname, mut cmd) = get_linker(sess, &linker, flavor);
-
-    let root = sess.target_filesearch(PathKind::Native).get_lib_path();
-    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() {
-            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);
-
-    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(root.join(obj));
-    }
-
-    if crate_type == config::CrateType::Executable && sess.crt_static() {
-        for obj in &sess.target.target.options.pre_link_objects_exe_crt {
-            cmd.arg(root.join(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 target_cpu = ::target_lexicon::HOST.to_string();
-        let mut linker = codegen_results.linker_info.to_linker(cmd, &sess, flavor, &target_cpu);
-        link_args(&mut *linker, flavor, sess, crate_type, tmpdir.path(),
-                  out_filename, codegen_results);
-        cmd = linker.finalize();
-    }
-    if let Some(args) = sess.target.target.options.late_link_args.get(&flavor) {
-        cmd.args(args);
-    }
-    for obj in &sess.target.target.options.post_link_objects {
-        cmd.arg(root.join(obj));
-    }
-    if sess.crt_static() {
-        for obj in &sess.target.target.options.post_link_objects_crt {
-            cmd.arg(root.join(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);
-    }
-
-    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
-    //
-    // Note that there'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...
-    let retry_on_segfault = env::var("RUSTC_RETRY_LINKER_ON_SEGFAULT").is_ok();
-    let mut prog;
-    let mut i = 0;
-    loop {
-        i += 1;
-        prog = exec_linker(sess, &mut cmd, out_filename, tmpdir.path());
-        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") {
-            for arg in cmd.take_args() {
-                if arg.to_string_lossy() != "-no-pie" {
-                    cmd.arg(arg);
-                }
-            }
-            continue;
-        }
-        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)) {
-            break
-        }
-    }
-
-    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();
-            }
-        },
-        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 or VS 2017 \
-                    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
-    {
-        if let Err(e) = Command::new("dsymutil").arg(out_filename).output() {
-            sess.fatal(&format!("failed to run dsymutil: {}", e))
-        }
-    }
-}
-
-fn link_args(cmd: &mut dyn Linker,
-             flavor: LinkerFlavor,
-             sess: &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;
-
-    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 a dynamic library then some platforms need to make sure
-    // that all symbols are exported correctly from the dynamic library.
-    if crate_type != config::CrateType::Executable ||
-       sess.target.target.options.is_like_emscripten {
-        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 {
-        if let Some(obj) = codegen_results.metadata_module.object.as_ref() {
-            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 !sess.crt_static() && !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(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() {
-        cmd.build_static_executable();
-    }
-
-    if sess.opts.debugging_opts.pgo_gen.enabled() {
-        cmd.pgo_gen();
-    }
-
-    // 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);
-}

src/link_copied.rs

@@ -1,336 +0,0 @@
-//! All functions here are copied from https://github.com/rust-lang/rust/blob/942864a000efd74b73e36bda5606b2cdb55ecf39/src/librustc_codegen_llvm/back/link.rs
-
-use std::path::Path;
-
-use rustc::middle::cstore::NativeLibraryKind;
-use rustc::middle::dependency_format::Linkage;
-use rustc::session::config::{self, OutputType, RUST_CGU_EXT};
-use rustc::session::Session;
-use rustc::util::common::time;
-use rustc_codegen_ssa::{METADATA_FILENAME, RLIB_BYTECODE_EXTENSION};
-use rustc_codegen_ssa::back::archive::ArchiveBuilder;
-use rustc_codegen_ssa::back::linker::*;
-use rustc_codegen_ssa::back::link::*;
-use rustc_data_structures::fx::FxHashSet;
-use rustc_fs_util::fix_windows_verbatim_for_gcc;
-
-use crate::prelude::*;
-
-use crate::archive::ArArchiveBuilder;
-
-// # 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)
-pub fn add_upstream_rust_crates(cmd: &mut dyn Linker,
-                            sess: &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 formats = sess.dependency_formats.borrow();
-    let data = formats.get(&crate_type).unwrap();
-
-    // 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;
-    let mut end_with = FxHashSet::default();
-    let info = &codegen_results.crate_info;
-    for &(cnum, _) in deps.iter().rev() {
-        if let Some(missing) = info.missing_lang_items.get(&cnum) {
-            end_with.extend(missing.iter().cloned());
-            if end_with.len() > 0 && group_end.is_none() {
-                group_end = Some(cnum);
-            }
-        }
-        end_with.retain(|item| info.lang_item_to_crate.get(item) != Some(&cnum));
-        if end_with.len() == 0 && 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(cmd, sess, codegen_results, tmpdir, crate_type, cnum);
-            }
-            _ if codegen_results.crate_info.sanitizer_runtime == Some(cnum) => {
-                link_sanitizer_runtime(cmd, sess, codegen_results, tmpdir, 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(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(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
-        }
-    }
-
-    // We must link the sanitizer runtime using -Wl,--whole-archive but since
-    // it's packed in a .rlib, it contains stuff that are not objects that will
-    // make the linker error. So we must remove those bits from the .rlib before
-    // linking it.
-    fn link_sanitizer_runtime(cmd: &mut dyn Linker,
-                              sess: &Session,
-                              codegen_results: &CodegenResults,
-                              tmpdir: &Path,
-                              cnum: CrateNum) {
-        let src = &codegen_results.crate_info.used_crate_source[&cnum];
-        let cratepath = &src.rlib.as_ref().unwrap().0;
-
-        if sess.target.target.options.is_like_osx {
-            // 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).
-            //
-            // FIXME: Remove this logic into librustc_*san once Cargo supports it
-            let rpath = cratepath.parent().unwrap();
-            let rpath = rpath.to_str().expect("non-utf8 component in path");
-            cmd.args(&["-Wl,-rpath".into(), "-Xlinker".into(), rpath.into()]);
-        }
-
-        let dst = tmpdir.join(cratepath.file_name().unwrap());
-        let mut archive = ArArchiveBuilder::new(sess, &dst, Some(cratepath));
-        archive.update_symbols();
-
-        for f in archive.src_files() {
-            if f.ends_with(RLIB_BYTECODE_EXTENSION) || f == METADATA_FILENAME {
-                archive.remove_file(&f);
-            }
-        }
-
-        archive.build();
-
-        cmd.link_whole_rlib(&dst);
-    }
-
-    // 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(cmd: &mut dyn Linker,
-                        sess: &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
-
-        time(sess, &format!("altering {}.rlib", name), || {
-            let mut archive = ArArchiveBuilder::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("-", "_");
-
-                // Look for `.rcgu.o` at the end of the filename to conclude
-                // that this is a Rust-related object file.
-                fn looks_like_rust(s: &str) -> bool {
-                    let path = Path::new(s);
-                    let ext = path.extension().and_then(|s| s.to_str());
-                    if ext != Some(OutputType::Object.extension()) {
-                        return false
-                    }
-                    let ext2 = path.file_stem()
-                        .and_then(|s| Path::new(s).extension())
-                        .and_then(|s| s.to_str());
-                    ext2 == Some(RUST_CGU_EXT)
-                }
-
-                let is_rust_object =
-                    canonical.starts_with(&canonical_name) &&
-                    looks_like_rust(&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) {
-        // If we're performing LTO, then it should have been previously required
-        // that all upstream rust dependencies were available in an rlib format.
-        assert!(!are_upstream_rust_objects_already_included(sess));
-
-        // 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(&unlib(&sess.target, filestem),
-                            parent.unwrap_or(Path::new("")));
-    }
-}