X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compiler%2Frustc_codegen_ssa%2Fsrc%2Fback%2Flink.rs;h=2091730af22672758311fb41df19fb3be433e499;hb=0b6dce43096aff3eb8a3e0e43442441185129025;hp=5a1ad792924fcf2ce45a784a9550e5af6d7603da;hpb=1e1e5b8d98750a162335f64ec3c792ce80c9866c;p=rust.git diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs index 5a1ad792924..2091730af22 100644 --- a/compiler/rustc_codegen_ssa/src/back/link.rs +++ b/compiler/rustc_codegen_ssa/src/back/link.rs @@ -6,9 +6,9 @@ use rustc_data_structures::temp_dir::MaybeTempDir; use rustc_errors::{ErrorGuaranteed, Handler}; use rustc_fs_util::fix_windows_verbatim_for_gcc; -use rustc_hir::def_id::CrateNum; +use rustc_hir::def_id::{CrateNum, LOCAL_CRATE}; use rustc_metadata::find_native_static_library; -use rustc_metadata::fs::{emit_metadata, METADATA_FILENAME}; +use rustc_metadata::fs::{emit_wrapper_file, METADATA_FILENAME}; use rustc_middle::middle::dependency_format::Linkage; use rustc_middle::middle::exported_symbols::SymbolExportKind; use rustc_session::config::{self, CFGuard, CrateType, DebugInfo, LdImpl, Lto, Strip}; @@ -24,12 +24,12 @@ use rustc_span::DebuggerVisualizerFile; use rustc_target::spec::crt_objects::{CrtObjects, LinkSelfContainedDefault}; use rustc_target::spec::{Cc, LinkOutputKind, LinkerFlavor, LinkerFlavorCli, Lld, PanicStrategy}; -use rustc_target::spec::{RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo, Target}; +use rustc_target::spec::{RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo}; use super::archive::{ArchiveBuilder, ArchiveBuilderBuilder}; use super::command::Command; use super::linker::{self, Linker}; -use super::metadata::{create_rmeta_file, MetadataPosition}; +use super::metadata::{create_wrapper_file, MetadataPosition}; use super::rpath::{self, RPathConfig}; use crate::{ errors, looks_like_rust_object_file, CodegenResults, CompiledModule, CrateInfo, NativeLib, @@ -44,7 +44,7 @@ use std::cell::OnceCell; use std::collections::BTreeSet; use std::ffi::OsString; -use std::fs::{File, OpenOptions}; +use std::fs::{read, File, OpenOptions}; use std::io::{BufWriter, Write}; use std::ops::Deref; use std::path::{Path, PathBuf}; @@ -292,8 +292,8 @@ fn link_rlib<'a>( let trailing_metadata = match flavor { RlibFlavor::Normal => { let (metadata, metadata_position) = - create_rmeta_file(sess, codegen_results.metadata.raw_data()); - let metadata = emit_metadata(sess, &metadata, tmpdir); + create_wrapper_file(sess, b".rmeta".to_vec(), codegen_results.metadata.raw_data()); + let metadata = emit_wrapper_file(sess, &metadata, tmpdir, METADATA_FILENAME); match metadata_position { MetadataPosition::First => { // Most of the time metadata in rlib files is wrapped in a "dummy" object @@ -376,12 +376,18 @@ fn link_rlib<'a>( let location = find_native_static_library(name.as_str(), lib.verbatim, &lib_search_paths, sess); if sess.opts.unstable_opts.packed_bundled_libs && flavor == RlibFlavor::Normal { - packed_bundled_libs.push(find_native_static_library( - lib.filename.unwrap().as_str(), + let filename = lib.filename.unwrap(); + let lib_path = find_native_static_library( + filename.as_str(), Some(true), &lib_search_paths, sess, - )); + ); + let src = read(lib_path) + .map_err(|e| sess.emit_fatal(errors::ReadFileError { message: e }))?; + let (data, _) = create_wrapper_file(sess, b".bundled_lib".to_vec(), &src); + let wrapper_file = emit_wrapper_file(sess, &data, tmpdir, filename.as_str()); + packed_bundled_libs.push(wrapper_file); continue; } ab.add_archive(&location, Box::new(|_| false)).unwrap_or_else(|error| { @@ -1582,6 +1588,9 @@ fn detect_self_contained_mingw(sess: &Session) -> bool { /// We only provide such support for a very limited number of targets. fn self_contained(sess: &Session, crate_type: CrateType) -> bool { if let Some(self_contained) = sess.opts.cg.link_self_contained { + if sess.target.link_self_contained == LinkSelfContainedDefault::False { + sess.emit_err(errors::UnsupportedLinkSelfContained); + } return self_contained; } @@ -2007,15 +2016,9 @@ fn linker_with_args<'a>( cmd.add_as_needed(); // Local native libraries of all kinds. - // - // If `-Zlink-native-libraries=false` is set, then the assumption is that an - // external build system already has the native dependencies defined, and it - // will provide them to the linker itself. - if sess.opts.unstable_opts.link_native_libraries { - add_local_native_libraries(cmd, sess, codegen_results); - } + add_local_native_libraries(cmd, sess, archive_builder_builder, codegen_results, tmpdir); - // Upstream rust libraries and their (possibly bundled) static native libraries. + // Upstream rust crates and their non-dynamic native libraries. add_upstream_rust_crates( cmd, sess, @@ -2026,13 +2029,7 @@ fn linker_with_args<'a>( ); // Dynamic native libraries from upstream crates. - // - // FIXME: Merge this to `add_upstream_rust_crates` so that all native libraries are linked - // together with their respective upstream crates, and in their originally specified order. - // This may be slightly breaking due to our use of `--as-needed` and needs a crater run. - if sess.opts.unstable_opts.link_native_libraries { - add_upstream_native_libraries(cmd, sess, codegen_results); - } + add_upstream_native_libraries(cmd, sess, archive_builder_builder, codegen_results, tmpdir); // Link with the import library generated for any raw-dylib functions. for (raw_dylib_name, raw_dylib_imports) in @@ -2276,42 +2273,46 @@ fn collect_natvis_visualizers( visualizer_paths } -/// # 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. -fn add_local_native_libraries( +fn add_native_libs_from_crate( cmd: &mut dyn Linker, sess: &Session, + archive_builder_builder: &dyn ArchiveBuilderBuilder, codegen_results: &CodegenResults, + tmpdir: &Path, + search_paths: &OnceCell>, + bundled_libs: &FxHashSet, + cnum: CrateNum, + link_static: bool, + link_dynamic: bool, ) { - 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)); - } - } + if !sess.opts.unstable_opts.link_native_libraries { + // If `-Zlink-native-libraries=false` is set, then the assumption is that an + // external build system already has the native dependencies defined, and it + // will provide them to the linker itself. + return; + } + + if link_static && cnum != LOCAL_CRATE && !bundled_libs.is_empty() { + // If rlib contains native libs as archives, unpack them to tmpdir. + let rlib = &codegen_results.crate_info.used_crate_source[&cnum].rlib.as_ref().unwrap().0; + archive_builder_builder + .extract_bundled_libs(rlib, tmpdir, &bundled_libs) + .unwrap_or_else(|e| sess.emit_fatal(e)); } - let relevant_libs = - codegen_results.crate_info.used_libraries.iter().filter(|l| relevant_lib(sess, l)); + let native_libs = match cnum { + LOCAL_CRATE => &codegen_results.crate_info.used_libraries, + _ => &codegen_results.crate_info.native_libraries[&cnum], + }; - let search_path = OnceCell::new(); let mut last = (None, NativeLibKind::Unspecified, None); - for lib in relevant_libs { + for lib in native_libs { let Some(name) = lib.name else { continue; }; - let name = name.as_str(); + if !relevant_lib(sess, lib) { + continue; + } // Skip if this library is the same as the last. last = if (lib.name, lib.kind, lib.verbatim) == last { @@ -2320,46 +2321,119 @@ fn add_local_native_libraries( (lib.name, lib.kind, lib.verbatim) }; + let name = name.as_str(); let verbatim = lib.verbatim.unwrap_or(false); match lib.kind { + NativeLibKind::Static { bundle, whole_archive } => { + if link_static { + let bundle = bundle.unwrap_or(true); + let whole_archive = whole_archive == Some(true) + // Backward compatibility case: this can be a rlib (so `+whole-archive` + // cannot be added explicitly if necessary, see the error in `fn link_rlib`) + // compiled as an executable due to `--test`. Use whole-archive implicitly, + // like before the introduction of native lib modifiers. + || (whole_archive == None + && bundle + && cnum == LOCAL_CRATE + && sess.opts.test); + + if bundle && cnum != LOCAL_CRATE { + if let Some(filename) = lib.filename { + // If rlib contains native libs as archives, they are unpacked to tmpdir. + let path = tmpdir.join(filename.as_str()); + if whole_archive { + cmd.link_whole_rlib(&path); + } else { + cmd.link_rlib(&path); + } + } + } else { + if whole_archive { + cmd.link_whole_staticlib( + name, + verbatim, + &search_paths.get_or_init(|| archive_search_paths(sess)), + ); + } else { + // HACK/FIXME: Fixup a circular dependency between libgcc and libc + // with glibc. This logic should be moved to the libc crate. + if cnum != LOCAL_CRATE + && sess.target.os == "linux" + && sess.target.env == "gnu" + && name == "c" + { + cmd.link_staticlib("gcc", false); + } + cmd.link_staticlib(name, verbatim) + } + } + } + } NativeLibKind::Dylib { as_needed } => { - cmd.link_dylib(name, verbatim, as_needed.unwrap_or(true)) + if link_dynamic { + cmd.link_dylib(name, verbatim, as_needed.unwrap_or(true)) + } } - NativeLibKind::Unspecified => cmd.link_dylib(name, verbatim, true), - NativeLibKind::Framework { as_needed } => { - cmd.link_framework(name, as_needed.unwrap_or(true)) + NativeLibKind::Unspecified => { + if link_dynamic { + cmd.link_dylib(name, verbatim, true); + } } - NativeLibKind::Static { whole_archive, bundle, .. } => { - if whole_archive == Some(true) - // Backward compatibility case: this can be a rlib (so `+whole-archive` cannot - // be added explicitly if necessary, see the error in `fn link_rlib`) compiled - // as an executable due to `--test`. Use whole-archive implicitly, like before - // the introduction of native lib modifiers. - || (whole_archive == None && bundle != Some(false) && sess.opts.test) - { - cmd.link_whole_staticlib( - name, - verbatim, - &search_path.get_or_init(|| archive_search_paths(sess)), - ); - } else { - cmd.link_staticlib(name, verbatim) + NativeLibKind::Framework { as_needed } => { + if link_dynamic { + cmd.link_framework(name, as_needed.unwrap_or(true)) } } NativeLibKind::RawDylib => { - // Ignore RawDylib here, they are handled separately in linker_with_args(). + // Handled separately in `linker_with_args`. } NativeLibKind::LinkArg => { - cmd.arg(name); + if link_static { + cmd.arg(name); + } } } } } -/// # Linking Rust crates and their non-bundled static libraries -/// -/// 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_local_native_libraries( + cmd: &mut dyn Linker, + sess: &Session, + archive_builder_builder: &dyn ArchiveBuilderBuilder, + codegen_results: &CodegenResults, + tmpdir: &Path, +) { + if sess.opts.unstable_opts.link_native_libraries { + // 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. + for search_path in sess.target_filesearch(PathKind::All).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 search_paths = OnceCell::new(); + // All static and dynamic native library dependencies are linked to the local crate. + let link_static = true; + let link_dynamic = true; + add_native_libs_from_crate( + cmd, + sess, + archive_builder_builder, + codegen_results, + tmpdir, + &search_paths, + &Default::default(), + LOCAL_CRATE, + link_static, + link_dynamic, + ); +} + fn add_upstream_rust_crates<'a>( cmd: &mut dyn Linker, sess: &'a Session, @@ -2375,7 +2449,6 @@ fn add_upstream_rust_crates<'a>( // 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 @@ -2383,346 +2456,234 @@ fn add_upstream_rust_crates<'a>( .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; - - let mut compiler_builtins = None; - let search_path = OnceCell::new(); - - for &cnum in deps.iter() { - // 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, - archive_builder_builder, - codegen_results, - tmpdir, - cnum, - &Default::default(), - ); - } - // 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 => { - let bundled_libs = if sess.opts.unstable_opts.packed_bundled_libs { - codegen_results.crate_info.native_libraries[&cnum] + let search_paths = OnceCell::new(); + for &cnum in &codegen_results.crate_info.used_crates { + // 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. + // We must always link crates `compiler_builtins` and `profiler_builtins` statically. + // Even if they were already included into a dylib + // (e.g. `libstd` when `-C prefer-dynamic` is used). + // FIXME: `dependency_formats` can report `profiler_builtins` as `NotLinked` for some + // reason, it shouldn't do that because `profiler_builtins` should indeed be linked. + let linkage = data[cnum.as_usize() - 1]; + let link_static_crate = linkage == Linkage::Static + || (linkage == Linkage::IncludedFromDylib || linkage == Linkage::NotLinked) + && (codegen_results.crate_info.compiler_builtins == Some(cnum) + || codegen_results.crate_info.profiler_runtime == Some(cnum)); + + let mut bundled_libs = Default::default(); + match linkage { + Linkage::Static | Linkage::IncludedFromDylib | Linkage::NotLinked => { + if link_static_crate { + bundled_libs = codegen_results.crate_info.native_libraries[&cnum] .iter() .filter_map(|lib| lib.filename) - .collect::>() - } else { - Default::default() - }; - add_static_crate( - cmd, - sess, - archive_builder_builder, - codegen_results, - tmpdir, - cnum, - &bundled_libs, - ); - - // Link static native libs with "-bundle" modifier 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 `-Zlink-native-libraries=false` is set, then the assumption is that an - // external build system already has the native dependencies defined, and it - // will provide them to the linker itself. - if sess.opts.unstable_opts.link_native_libraries { - if sess.opts.unstable_opts.packed_bundled_libs { - // If rlib contains native libs as archives, unpack them to tmpdir. - let rlib = &src.rlib.as_ref().unwrap().0; - archive_builder_builder - .extract_bundled_libs(rlib, tmpdir, &bundled_libs) - .unwrap_or_else(|e| sess.emit_fatal(e)); - } - - let mut last = (None, NativeLibKind::Unspecified, None); - for lib in &codegen_results.crate_info.native_libraries[&cnum] { - let Some(name) = lib.name else { - continue; - }; - let name = name.as_str(); - if !relevant_lib(sess, lib) { - continue; - } - - // Skip if this library is the same as the last. - last = if (lib.name, lib.kind, lib.verbatim) == last { - continue; - } else { - (lib.name, lib.kind, lib.verbatim) - }; - - match lib.kind { - NativeLibKind::Static { - bundle: Some(false), - whole_archive: Some(true), - } => { - cmd.link_whole_staticlib( - name, - lib.verbatim.unwrap_or(false), - search_path.get_or_init(|| archive_search_paths(sess)), - ); - } - NativeLibKind::Static { - bundle: Some(false), - whole_archive: Some(false) | None, - } => { - // HACK/FIXME: Fixup a circular dependency between libgcc and libc - // with glibc. This logic should be moved to the libc crate. - if sess.target.os == "linux" - && sess.target.env == "gnu" - && name == "c" - { - cmd.link_staticlib("gcc", false); - } - cmd.link_staticlib(name, lib.verbatim.unwrap_or(false)); - } - NativeLibKind::LinkArg => { - cmd.arg(name); - } - NativeLibKind::Dylib { .. } - | NativeLibKind::Framework { .. } - | NativeLibKind::Unspecified - | NativeLibKind::RawDylib => {} - NativeLibKind::Static { bundle: Some(true) | None, whole_archive } => { - if sess.opts.unstable_opts.packed_bundled_libs { - // If rlib contains native libs as archives, they are unpacked to tmpdir. - let path = tmpdir.join(lib.filename.unwrap().as_str()); - if whole_archive == Some(true) { - cmd.link_whole_rlib(&path); - } else { - cmd.link_rlib(&path); - } - } - } - } - } + .collect(); + add_static_crate( + cmd, + sess, + archive_builder_builder, + codegen_results, + tmpdir, + cnum, + &bundled_libs, + ); } } - Linkage::Dynamic => add_dynamic_crate(cmd, sess, &src.dylib.as_ref().unwrap().0), + Linkage::Dynamic => { + let src = &codegen_results.crate_info.used_crate_source[&cnum]; + add_dynamic_crate(cmd, sess, &src.dylib.as_ref().unwrap().0); + } } - } - // 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( + // Static libraries are linked for a subset of linked upstream crates. + // 1. If the upstream crate is a directly linked rlib then we must link the native library + // because the rlib is just an archive. + // 2. If the upstream crate is a dylib or a rlib linked through dylib, then we do not link + // the native library because it is already linked into the dylib, and even if + // inline/const/generic functions from the dylib can refer to symbols from the native + // library, those symbols should be exported and available from the dylib anyway. + // 3. Libraries bundled into `(compiler,profiler)_builtins` are special, see above. + let link_static = link_static_crate; + // Dynamic libraries are not linked here, see the FIXME in `add_upstream_native_libraries`. + let link_dynamic = false; + add_native_libs_from_crate( cmd, sess, archive_builder_builder, codegen_results, tmpdir, + &search_paths, + &bundled_libs, cnum, - &Default::default(), + link_static, + link_dynamic, ); } +} - // Converts a library file-stem into a cc -l argument - fn unlib<'a>(target: &Target, stem: &'a str) -> &'a str { - if stem.starts_with("lib") && !target.is_like_windows { &stem[3..] } else { stem } +fn add_upstream_native_libraries( + cmd: &mut dyn Linker, + sess: &Session, + archive_builder_builder: &dyn ArchiveBuilderBuilder, + codegen_results: &CodegenResults, + tmpdir: &Path, +) { + let search_path = OnceCell::new(); + for &cnum in &codegen_results.crate_info.used_crates { + // Static libraries are not linked here, they are linked in `add_upstream_rust_crates`. + // FIXME: Merge this function to `add_upstream_rust_crates` so that all native libraries + // are linked together with their respective upstream crates, and in their originally + // specified order. This is slightly breaking due to our use of `--as-needed` (see crater + // results in https://github.com/rust-lang/rust/pull/102832#issuecomment-1279772306). + let link_static = false; + // Dynamic libraries are linked for all linked upstream crates. + // 1. If the upstream crate is a directly linked rlib then we must link the native library + // because the rlib is just an archive. + // 2. If the upstream crate is a dylib or a rlib linked through dylib, then we have to link + // the native library too because inline/const/generic functions from the dylib can refer + // to symbols from the native library, so the native library providing those symbols should + // be available when linking our final binary. + let link_dynamic = true; + add_native_libs_from_crate( + cmd, + sess, + archive_builder_builder, + codegen_results, + tmpdir, + &search_path, + &Default::default(), + cnum, + link_static, + link_dynamic, + ); } +} - // 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, - // namely that we remove upstream object files. - // - // 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. - // - // Note, however, that if we're not doing LTO 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>( - cmd: &mut dyn Linker, - sess: &'a Session, - archive_builder_builder: &dyn ArchiveBuilderBuilder, - codegen_results: &CodegenResults, - tmpdir: &Path, - cnum: CrateNum, - bundled_lib_file_names: &FxHashSet, - ) { - let src = &codegen_results.crate_info.used_crate_source[&cnum]; - let cratepath = &src.rlib.as_ref().unwrap().0; - - let mut link_upstream = |path: &Path| { - cmd.link_rlib(&fix_windows_verbatim_for_gcc(path)); - }; - - // 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| { - matches!(lib.kind, NativeLibKind::Static { bundle: None | Some(true), .. }) - && !relevant_lib(sess, lib) - }); - - if (!are_upstream_rust_objects_already_included(sess) - || ignored_for_lto(sess, &codegen_results.crate_info, cnum)) - && !skip_native - { - link_upstream(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 - let bundled_lib_file_names = bundled_lib_file_names.clone(); - - sess.prof.generic_activity_with_arg("link_altering_rlib", name).run(|| { - let canonical_name = name.replace('-', "_"); - let upstream_rust_objects_already_included = - are_upstream_rust_objects_already_included(sess); - let is_builtins = sess.target.no_builtins - || !codegen_results.crate_info.is_no_builtins.contains(&cnum); - - let mut archive = archive_builder_builder.new_archive_builder(sess); - if let Err(error) = archive.add_archive( - cratepath, - Box::new(move |f| { - if f == METADATA_FILENAME { - return true; - } +// 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, +// namely that we remove upstream object files. +// +// 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. +// +// Note, however, that if we're not doing LTO 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>( + cmd: &mut dyn Linker, + sess: &'a Session, + archive_builder_builder: &dyn ArchiveBuilderBuilder, + codegen_results: &CodegenResults, + tmpdir: &Path, + cnum: CrateNum, + bundled_lib_file_names: &FxHashSet, +) { + let src = &codegen_results.crate_info.used_crate_source[&cnum]; + let cratepath = &src.rlib.as_ref().unwrap().0; - let canonical = f.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 = - upstream_rust_objects_already_included && is_rust_object && is_builtins; - - // We skip native libraries because: - // 1. This native libraries won't be used from the generated rlib, - // so we can throw them away to avoid the copying work. - // 2. We can't allow it to be a single remaining entry in archive - // as some linkers may complain on that. - if bundled_lib_file_names.contains(&Symbol::intern(f)) { - return true; - } + let mut link_upstream = |path: &Path| { + cmd.link_rlib(&fix_windows_verbatim_for_gcc(path)); + }; - if skip_because_cfg_say_so || skip_because_lto { - return true; - } + // 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| { + matches!(lib.kind, NativeLibKind::Static { bundle: None | Some(true), .. }) + && !relevant_lib(sess, lib) + }); - false - }), - ) { - sess.emit_fatal(errors::RlibArchiveBuildFailure { error }); - } - if archive.build(&dst) { - link_upstream(&dst); - } - }); + if (!are_upstream_rust_objects_already_included(sess) + || ignored_for_lto(sess, &codegen_results.crate_info, cnum)) + && !skip_native + { + link_upstream(cratepath); + return; } - // 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( - &unlib(&sess.target, filestem), - parent.unwrap_or_else(|| Path::new("")), - ); - } -} + 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 + let bundled_lib_file_names = bundled_lib_file_names.clone(); -/// 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. -fn add_upstream_native_libraries( - cmd: &mut dyn Linker, - sess: &Session, - codegen_results: &CodegenResults, -) { - let mut last = (None, NativeLibKind::Unspecified, None); - for &cnum in &codegen_results.crate_info.used_crates { - for lib in codegen_results.crate_info.native_libraries[&cnum].iter() { - let Some(name) = lib.name else { - continue; - }; - let name = name.as_str(); - if !relevant_lib(sess, &lib) { - continue; - } + sess.prof.generic_activity_with_arg("link_altering_rlib", name).run(|| { + let canonical_name = name.replace('-', "_"); + let upstream_rust_objects_already_included = + are_upstream_rust_objects_already_included(sess); + let is_builtins = + sess.target.no_builtins || !codegen_results.crate_info.is_no_builtins.contains(&cnum); - // Skip if this library is the same as the last. - last = if (lib.name, lib.kind, lib.verbatim) == last { - continue; - } else { - (lib.name, lib.kind, lib.verbatim) - }; + let mut archive = archive_builder_builder.new_archive_builder(sess); + if let Err(e) = archive.add_archive( + cratepath, + Box::new(move |f| { + if f == METADATA_FILENAME { + return true; + } - let verbatim = lib.verbatim.unwrap_or(false); - match lib.kind { - NativeLibKind::Dylib { as_needed } => { - cmd.link_dylib(name, verbatim, as_needed.unwrap_or(true)) + let canonical = f.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 = + upstream_rust_objects_already_included && is_rust_object && is_builtins; + + // We skip native libraries because: + // 1. This native libraries won't be used from the generated rlib, + // so we can throw them away to avoid the copying work. + // 2. We can't allow it to be a single remaining entry in archive + // as some linkers may complain on that. + if bundled_lib_file_names.contains(&Symbol::intern(f)) { + return true; } - NativeLibKind::Unspecified => cmd.link_dylib(name, verbatim, true), - NativeLibKind::Framework { as_needed } => { - cmd.link_framework(name, as_needed.unwrap_or(true)) + + if skip_because_cfg_say_so || skip_because_lto { + return true; } - // ignore static native libraries here as we've - // already included them in add_local_native_libraries and - // add_upstream_rust_crates - NativeLibKind::Static { .. } => {} - NativeLibKind::RawDylib | NativeLibKind::LinkArg => {} - } + + false + }), + ) { + sess.fatal(&format!("failed to build archive from rlib: {}", e)); } - } + if archive.build(&dst) { + link_upstream(&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 stem = cratepath.file_stem().unwrap().to_str().unwrap(); + // Convert library file-stem into a cc -l argument. + let prefix = if stem.starts_with("lib") && !sess.target.is_like_windows { 3 } else { 0 }; + cmd.link_rust_dylib(&stem[prefix..], parent.unwrap_or_else(|| Path::new(""))); } fn relevant_lib(sess: &Session, lib: &NativeLib) -> bool {