From 472b591f90c237efb3683b9addc49b98ef0fb797 Mon Sep 17 00:00:00 2001 From: bjorn3 Date: Mon, 1 Apr 2019 19:34:26 +0200 Subject: [PATCH] Use rustc_codegen_ssa::back::link instead of copy pasted version --- src/lib.rs | 26 ++- src/link.rs | 463 --------------------------------------------- src/link_copied.rs | 336 -------------------------------- 3 files changed, 12 insertions(+), 813 deletions(-) delete mode 100644 src/link.rs delete mode 100644 src/link_copied.rs diff --git a/src/lib.rs b/src/lib.rs index 8fb35c6e342..53dc644ddc4 100644 --- a/src/lib.rs +++ b/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; @@ -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::() .expect("Expected CraneliftCodegenBackend's CodegenResult, found Box"); - for &crate_type in sess.crate_types.borrow().iter() { - let output_name = out_filename(sess, crate_type, &outputs, &res.crate_name.as_str()); - match crate_type { - CrateType::Rlib => link::link_rlib(sess, &res, output_name), - CrateType::Dylib | CrateType::Executable => { - link::link_natively(sess, crate_type, &res, &output_name); - } - _ => sess.fatal(&format!("Unsupported crate type: {:?}", crate_type)), - } - } + let target_cpu = ::target_lexicon::HOST.to_string(); + link_binary::>( + sess, + &codegen_results, + outputs, + &codegen_results.crate_name.as_str(), + &target_cpu, + ); + Ok(()) } } diff --git a/src/link.rs b/src/link.rs deleted file mode 100644 index 7694892a8e8..00000000000 --- a/src/link.rs +++ /dev/null @@ -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); -} diff --git a/src/link_copied.rs b/src/link_copied.rs deleted file mode 100644 index a1205b07943..00000000000 --- a/src/link_copied.rs +++ /dev/null @@ -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(""))); - } -}