diff options
| -rw-r--r-- | src/librustc_codegen_llvm/back/link.rs | 376 | ||||
| -rw-r--r-- | src/librustc_codegen_ssa/back/link.rs | 381 |
2 files changed, 382 insertions, 375 deletions
diff --git a/src/librustc_codegen_llvm/back/link.rs b/src/librustc_codegen_llvm/back/link.rs index 6a3c2adc856..395da953d0b 100644 --- a/src/librustc_codegen_llvm/back/link.rs +++ b/src/librustc_codegen_llvm/back/link.rs @@ -7,15 +7,14 @@ use crate::metadata::METADATA_FILENAME; use crate::context::get_reloc_model; use crate::llvm; use rustc_codegen_ssa::back::linker::Linker; -use rustc_codegen_ssa::back::link::{remove, ignored_for_lto, each_linked_rlib, linker_and_flavor, - get_linker}; +use rustc_codegen_ssa::back::link::*; use rustc_codegen_ssa::back::command::Command; use rustc::session::config::{self, DebugInfo, OutputFilenames, OutputType, PrintRequest}; -use rustc::session::config::{RUST_CGU_EXT, Lto, Sanitizer}; +use rustc::session::config::{RUST_CGU_EXT, Sanitizer}; use rustc::session::filesearch; use rustc::session::search_paths::PathKind; use rustc::session::Session; -use rustc::middle::cstore::{NativeLibrary, NativeLibraryKind}; +use rustc::middle::cstore::NativeLibraryKind; use rustc::middle::dependency_format::Linkage; use rustc_codegen_ssa::CodegenResults; use rustc::util::common::{time, time_ext}; @@ -28,14 +27,10 @@ use rustc_data_structures::fx::FxHashSet; use std::ascii; use std::char; use std::env; -use std::fmt; use std::fs; use std::io; -use std::iter; use std::path::{Path, PathBuf}; -use std::process::{Output, Stdio}; use std::str; -use syntax::attr; pub use rustc_codegen_utils::link::{find_crate_name, filename_for_input, default_output_for_target, invalid_output_for_target, filename_for_metadata, @@ -96,52 +91,6 @@ pub(crate) fn link_binary(sess: &Session, out_filenames } -/// Returns a boolean indicating whether we should preserve the object files on -/// the filesystem for their debug information. This is often useful with -/// split-dwarf like schemes. -fn preserve_objects_for_their_debuginfo(sess: &Session) -> bool { - // If the objects don't have debuginfo there's nothing to preserve. - if sess.opts.debuginfo == DebugInfo::None { - return false - } - - // If we're only producing artifacts that are archives, no need to preserve - // the objects as they're losslessly contained inside the archives. - let output_linked = sess.crate_types.borrow() - .iter() - .any(|&x| x != config::CrateType::Rlib && x != config::CrateType::Staticlib); - if !output_linked { - return false - } - - // If we're on OSX then the equivalent of split dwarf is turned on by - // default. The final executable won't actually have any debug information - // except it'll have pointers to elsewhere. Historically we've always run - // `dsymutil` to "link all the dwarf together" but this is actually sort of - // a bummer for incremental compilation! (the whole point of split dwarf is - // that you don't do this sort of dwarf link). - // - // Basically as a result this just means that if we're on OSX and we're - // *not* running dsymutil then the object files are the only source of truth - // for debug information, so we must preserve them. - if sess.target.target.options.is_like_osx { - match sess.opts.debugging_opts.run_dsymutil { - // dsymutil is not being run, preserve objects - Some(false) => return true, - - // dsymutil is being run, no need to preserve the objects - Some(true) => return false, - - // The default historical behavior was to always run dsymutil, so - // we're preserving that temporarily, but we're likely to switch the - // default soon. - None => return false, - } - } - - false -} - fn link_binary_output(sess: &Session, codegen_results: &CodegenResults, crate_type: config::CrateType, @@ -201,10 +150,6 @@ fn link_binary_output(sess: &Session, out_filenames } -fn archive_search_paths(sess: &Session) -> Vec<PathBuf> { - sess.target_filesearch(PathKind::Native).search_path_dirs() -} - fn archive_config<'a>(sess: &'a Session, output: &Path, input: Option<&Path>) -> ArchiveConfig<'a> { @@ -415,53 +360,6 @@ fn link_staticlib(sess: &Session, } } -fn print_native_static_libs(sess: &Session, all_native_libs: &[NativeLibrary]) { - let lib_args: Vec<_> = all_native_libs.iter() - .filter(|l| relevant_lib(sess, l)) - .filter_map(|lib| { - let name = lib.name?; - match lib.kind { - NativeLibraryKind::NativeStaticNobundle | - NativeLibraryKind::NativeUnknown => { - if sess.target.target.options.is_like_msvc { - Some(format!("{}.lib", name)) - } else { - Some(format!("-l{}", name)) - } - }, - NativeLibraryKind::NativeFramework => { - // ld-only syntax, since there are no frameworks in MSVC - Some(format!("-framework {}", name)) - }, - // These are included, no need to print them - NativeLibraryKind::NativeStatic => None, - } - }) - .collect(); - if !lib_args.is_empty() { - sess.note_without_error("Link against the following native artifacts when linking \ - against this static library. The order and any duplication \ - can be significant on some platforms."); - // Prefix for greppability - sess.note_without_error(&format!("native-static-libs: {}", &lib_args.join(" "))); - } -} - -fn get_file_path(sess: &Session, name: &str) -> PathBuf { - let fs = sess.target_filesearch(PathKind::Native); - let file_path = fs.get_lib_path().join(name); - if file_path.exists() { - return file_path - } - for search_path in fs.search_paths() { - let file_path = search_path.dir.join(name); - if file_path.exists() { - return file_path - } - } - PathBuf::from(name) -} - // Create a dynamic library or executable // // This will invoke the system linker/cc to create the resulting file. This @@ -706,147 +604,6 @@ fn link_natively(sess: &Session, } } -fn exec_linker(sess: &Session, cmd: &mut Command, out_filename: &Path, tmpdir: &Path) - -> io::Result<Output> -{ - // When attempting to spawn the linker we run a risk of blowing out the - // size limits for spawning a new process with respect to the arguments - // we pass on the command line. - // - // Here we attempt to handle errors from the OS saying "your list of - // arguments is too big" by reinvoking the linker again with an `@`-file - // that contains all the arguments. The theory is that this is then - // accepted on all linkers and the linker will read all its options out of - // there instead of looking at the command line. - if !cmd.very_likely_to_exceed_some_spawn_limit() { - match cmd.command().stdout(Stdio::piped()).stderr(Stdio::piped()).spawn() { - Ok(child) => { - let output = child.wait_with_output(); - flush_linked_file(&output, out_filename)?; - return output; - } - Err(ref e) if command_line_too_big(e) => { - info!("command line to linker was too big: {}", e); - } - Err(e) => return Err(e) - } - } - - info!("falling back to passing arguments to linker via an @-file"); - let mut cmd2 = cmd.clone(); - let mut args = String::new(); - for arg in cmd2.take_args() { - args.push_str(&Escape { - arg: arg.to_str().unwrap(), - is_like_msvc: sess.target.target.options.is_like_msvc, - }.to_string()); - args.push_str("\n"); - } - let file = tmpdir.join("linker-arguments"); - let bytes = if sess.target.target.options.is_like_msvc { - let mut out = Vec::with_capacity((1 + args.len()) * 2); - // start the stream with a UTF-16 BOM - for c in iter::once(0xFEFF).chain(args.encode_utf16()) { - // encode in little endian - out.push(c as u8); - out.push((c >> 8) as u8); - } - out - } else { - args.into_bytes() - }; - fs::write(&file, &bytes)?; - cmd2.arg(format!("@{}", file.display())); - info!("invoking linker {:?}", cmd2); - let output = cmd2.output(); - flush_linked_file(&output, out_filename)?; - return output; - - #[cfg(unix)] - fn flush_linked_file(_: &io::Result<Output>, _: &Path) -> io::Result<()> { - Ok(()) - } - - #[cfg(windows)] - fn flush_linked_file(command_output: &io::Result<Output>, out_filename: &Path) - -> io::Result<()> - { - // On Windows, under high I/O load, output buffers are sometimes not flushed, - // even long after process exit, causing nasty, non-reproducible output bugs. - // - // File::sync_all() calls FlushFileBuffers() down the line, which solves the problem. - // - // А full writeup of the original Chrome bug can be found at - // randomascii.wordpress.com/2018/02/25/compiler-bug-linker-bug-windows-kernel-bug/amp - - if let &Ok(ref out) = command_output { - if out.status.success() { - if let Ok(of) = fs::OpenOptions::new().write(true).open(out_filename) { - of.sync_all()?; - } - } - } - - Ok(()) - } - - #[cfg(unix)] - fn command_line_too_big(err: &io::Error) -> bool { - err.raw_os_error() == Some(::libc::E2BIG) - } - - #[cfg(windows)] - fn command_line_too_big(err: &io::Error) -> bool { - const ERROR_FILENAME_EXCED_RANGE: i32 = 206; - err.raw_os_error() == Some(ERROR_FILENAME_EXCED_RANGE) - } - - struct Escape<'a> { - arg: &'a str, - is_like_msvc: bool, - } - - impl<'a> fmt::Display for Escape<'a> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - if self.is_like_msvc { - // This is "documented" at - // https://msdn.microsoft.com/en-us/library/4xdcbak7.aspx - // - // Unfortunately there's not a great specification of the - // syntax I could find online (at least) but some local - // testing showed that this seemed sufficient-ish to catch - // at least a few edge cases. - write!(f, "\"")?; - for c in self.arg.chars() { - match c { - '"' => write!(f, "\\{}", c)?, - c => write!(f, "{}", c)?, - } - } - write!(f, "\"")?; - } else { - // This is documented at https://linux.die.net/man/1/ld, namely: - // - // > Options in file are separated by whitespace. A whitespace - // > character may be included in an option by surrounding the - // > entire option in either single or double quotes. Any - // > character (including a backslash) may be included by - // > prefixing the character to be included with a backslash. - // - // We put an argument on each line, so all we need to do is - // ensure the line is interpreted as one whole argument. - for c in self.arg.chars() { - match c { - '\\' | ' ' => write!(f, "\\{}", c)?, - c => write!(f, "{}", c)?, - } - } - } - Ok(()) - } - } -} - fn link_args(cmd: &mut dyn Linker, flavor: LinkerFlavor, sess: &Session, @@ -1051,48 +808,6 @@ fn link_args(cmd: &mut dyn Linker, cmd.args(&used_link_args); } -// # Native library linking -// -// User-supplied library search paths (-L on the command line). These are -// the same paths used to find Rust crates, so some of them may have been -// added already by the previous crate linking code. This only allows them -// to be found at compile time so it is still entirely up to outside -// forces to make sure that library can be found at runtime. -// -// Also note that the native libraries linked here are only the ones located -// in the current crate. Upstream crates with native library dependencies -// may have their native library pulled in above. -fn add_local_native_libraries(cmd: &mut dyn Linker, - sess: &Session, - codegen_results: &CodegenResults) { - let filesearch = sess.target_filesearch(PathKind::All); - for search_path in filesearch.search_paths() { - match search_path.kind { - PathKind::Framework => { cmd.framework_path(&search_path.dir); } - _ => { cmd.include_path(&fix_windows_verbatim_for_gcc(&search_path.dir)); } - } - } - - let relevant_libs = codegen_results.crate_info.used_libraries.iter().filter(|l| { - relevant_lib(sess, l) - }); - - let search_path = archive_search_paths(sess); - for lib in relevant_libs { - let name = match lib.name { - Some(ref l) => l, - None => continue, - }; - match lib.kind { - NativeLibraryKind::NativeUnknown => cmd.link_dylib(&name.as_str()), - NativeLibraryKind::NativeFramework => cmd.link_framework(&name.as_str()), - NativeLibraryKind::NativeStaticNobundle => cmd.link_staticlib(&name.as_str()), - NativeLibraryKind::NativeStatic => cmd.link_whole_staticlib(&name.as_str(), - &search_path) - } - } -} - // # Rust Crate linking // // Rust crates are not considered at all when creating an rlib output. All @@ -1407,88 +1122,3 @@ fn add_upstream_rust_crates(cmd: &mut dyn Linker, parent.unwrap_or(Path::new(""))); } } - -// Link in all of our upstream crates' native dependencies. Remember that -// all of these upstream native dependencies are all non-static -// dependencies. We've got two cases then: -// -// 1. The upstream crate is an rlib. In this case we *must* link in the -// native dependency because the rlib is just an archive. -// -// 2. The upstream crate is a dylib. In order to use the dylib, we have to -// have the dependency present on the system somewhere. Thus, we don't -// gain a whole lot from not linking in the dynamic dependency to this -// crate as well. -// -// The use case for this is a little subtle. In theory the native -// dependencies of a crate are purely an implementation detail of the crate -// itself, but the problem arises with generic and inlined functions. If a -// generic function calls a native function, then the generic function must -// be instantiated in the target crate, meaning that the native symbol must -// also be resolved in the target crate. -fn add_upstream_native_libraries(cmd: &mut dyn Linker, - sess: &Session, - codegen_results: &CodegenResults, - crate_type: config::CrateType) { - // Be sure to use a topological sorting of crates because there may be - // interdependencies between native libraries. When passing -nodefaultlibs, - // for example, almost all native libraries depend on libc, so we have to - // make sure that's all the way at the right (liblibc is near the base of - // the dependency chain). - // - // This passes RequireStatic, but the actual requirement doesn't matter, - // we're just getting an ordering of crate numbers, we're not worried about - // the paths. - let formats = sess.dependency_formats.borrow(); - let data = formats.get(&crate_type).unwrap(); - - let crates = &codegen_results.crate_info.used_crates_static; - for &(cnum, _) in crates { - for lib in codegen_results.crate_info.native_libraries[&cnum].iter() { - let name = match lib.name { - Some(ref l) => l, - None => continue, - }; - if !relevant_lib(sess, &lib) { - continue - } - match lib.kind { - NativeLibraryKind::NativeUnknown => cmd.link_dylib(&name.as_str()), - NativeLibraryKind::NativeFramework => cmd.link_framework(&name.as_str()), - NativeLibraryKind::NativeStaticNobundle => { - // Link "static-nobundle" native libs only if the crate they originate from - // is being linked statically to the current crate. If it's linked dynamically - // or is an rlib already included via some other dylib crate, the symbols from - // native libs will have already been included in that dylib. - if data[cnum.as_usize() - 1] == Linkage::Static { - cmd.link_staticlib(&name.as_str()) - } - }, - // ignore statically included native libraries here as we've - // already included them when we included the rust library - // previously - NativeLibraryKind::NativeStatic => {} - } - } - } -} - -fn relevant_lib(sess: &Session, lib: &NativeLibrary) -> bool { - match lib.cfg { - Some(ref cfg) => attr::cfg_matches(cfg, &sess.parse_sess, None), - None => true, - } -} - -fn are_upstream_rust_objects_already_included(sess: &Session) -> bool { - match sess.lto() { - Lto::Fat => true, - Lto::Thin => { - // If we defer LTO to the linker, we haven't run LTO ourselves, so - // any upstream object files have not been copied yet. - !sess.opts.cg.linker_plugin_lto.enabled() - } - Lto::No | - Lto::ThinLocal => false, - } -} diff --git a/src/librustc_codegen_ssa/back/link.rs b/src/librustc_codegen_ssa/back/link.rs index a0e2dcd646d..3d7ca251fcf 100644 --- a/src/librustc_codegen_ssa/back/link.rs +++ b/src/librustc_codegen_ssa/back/link.rs @@ -4,18 +4,25 @@ use rustc::session::{Session, config}; use rustc::session::search_paths::PathKind; use rustc::middle::dependency_format::Linkage; -use rustc::middle::cstore::LibSource; +use rustc::middle::cstore::{LibSource, NativeLibrary, NativeLibraryKind}; use rustc_target::spec::LinkerFlavor; use rustc::hir::def_id::CrateNum; +use rustc_fs_util::fix_windows_verbatim_for_gcc; use super::command::Command; -use crate::CrateInfo; +use crate::{CrateInfo, CodegenResults}; +use crate::back::linker::Linker; use cc::windows_registry; +use std::fmt; use std::fs; +use std::io; use std::path::{Path, PathBuf}; +use std::process::{Output, Stdio}; use std::env; +pub use rustc_codegen_utils::link::*; + pub fn remove(sess: &Session, path: &Path) { if let Err(e) = fs::remove_file(path) { sess.err(&format!("failed to remove {}: {}", @@ -200,3 +207,373 @@ pub fn linker_and_flavor(sess: &Session) -> (PathBuf, LinkerFlavor) { bug!("Not enough information provided to determine how to invoke the linker"); } + +/// Returns a boolean indicating whether we should preserve the object files on +/// the filesystem for their debug information. This is often useful with +/// split-dwarf like schemes. +pub fn preserve_objects_for_their_debuginfo(sess: &Session) -> bool { + // If the objects don't have debuginfo there's nothing to preserve. + if sess.opts.debuginfo == config::DebugInfo::None { + return false + } + + // If we're only producing artifacts that are archives, no need to preserve + // the objects as they're losslessly contained inside the archives. + let output_linked = sess.crate_types.borrow() + .iter() + .any(|&x| x != config::CrateType::Rlib && x != config::CrateType::Staticlib); + if !output_linked { + return false + } + + // If we're on OSX then the equivalent of split dwarf is turned on by + // default. The final executable won't actually have any debug information + // except it'll have pointers to elsewhere. Historically we've always run + // `dsymutil` to "link all the dwarf together" but this is actually sort of + // a bummer for incremental compilation! (the whole point of split dwarf is + // that you don't do this sort of dwarf link). + // + // Basically as a result this just means that if we're on OSX and we're + // *not* running dsymutil then the object files are the only source of truth + // for debug information, so we must preserve them. + if sess.target.target.options.is_like_osx { + match sess.opts.debugging_opts.run_dsymutil { + // dsymutil is not being run, preserve objects + Some(false) => return true, + + // dsymutil is being run, no need to preserve the objects + Some(true) => return false, + + // The default historical behavior was to always run dsymutil, so + // we're preserving that temporarily, but we're likely to switch the + // default soon. + None => return false, + } + } + + false +} + +pub fn archive_search_paths(sess: &Session) -> Vec<PathBuf> { + sess.target_filesearch(PathKind::Native).search_path_dirs() +} + +enum RlibFlavor { + Normal, + StaticlibBase, +} + +pub fn print_native_static_libs(sess: &Session, all_native_libs: &[NativeLibrary]) { + let lib_args: Vec<_> = all_native_libs.iter() + .filter(|l| relevant_lib(sess, l)) + .filter_map(|lib| { + let name = lib.name?; + match lib.kind { + NativeLibraryKind::NativeStaticNobundle | + NativeLibraryKind::NativeUnknown => { + if sess.target.target.options.is_like_msvc { + Some(format!("{}.lib", name)) + } else { + Some(format!("-l{}", name)) + } + }, + NativeLibraryKind::NativeFramework => { + // ld-only syntax, since there are no frameworks in MSVC + Some(format!("-framework {}", name)) + }, + // These are included, no need to print them + NativeLibraryKind::NativeStatic => None, + } + }) + .collect(); + if !lib_args.is_empty() { + sess.note_without_error("Link against the following native artifacts when linking \ + against this static library. The order and any duplication \ + can be significant on some platforms."); + // Prefix for greppability + sess.note_without_error(&format!("native-static-libs: {}", &lib_args.join(" "))); + } +} + +pub fn get_file_path(sess: &Session, name: &str) -> PathBuf { + let fs = sess.target_filesearch(PathKind::Native); + let file_path = fs.get_lib_path().join(name); + if file_path.exists() { + return file_path + } + for search_path in fs.search_paths() { + let file_path = search_path.dir.join(name); + if file_path.exists() { + return file_path + } + } + PathBuf::from(name) +} + +pub fn exec_linker(sess: &Session, cmd: &mut Command, out_filename: &Path, tmpdir: &Path) + -> io::Result<Output> +{ + // When attempting to spawn the linker we run a risk of blowing out the + // size limits for spawning a new process with respect to the arguments + // we pass on the command line. + // + // Here we attempt to handle errors from the OS saying "your list of + // arguments is too big" by reinvoking the linker again with an `@`-file + // that contains all the arguments. The theory is that this is then + // accepted on all linkers and the linker will read all its options out of + // there instead of looking at the command line. + if !cmd.very_likely_to_exceed_some_spawn_limit() { + match cmd.command().stdout(Stdio::piped()).stderr(Stdio::piped()).spawn() { + Ok(child) => { + let output = child.wait_with_output(); + flush_linked_file(&output, out_filename)?; + return output; + } + Err(ref e) if command_line_too_big(e) => { + info!("command line to linker was too big: {}", e); + } + Err(e) => return Err(e) + } + } + + info!("falling back to passing arguments to linker via an @-file"); + let mut cmd2 = cmd.clone(); + let mut args = String::new(); + for arg in cmd2.take_args() { + args.push_str(&Escape { + arg: arg.to_str().unwrap(), + is_like_msvc: sess.target.target.options.is_like_msvc, + }.to_string()); + args.push_str("\n"); + } + let file = tmpdir.join("linker-arguments"); + let bytes = if sess.target.target.options.is_like_msvc { + let mut out = Vec::with_capacity((1 + args.len()) * 2); + // start the stream with a UTF-16 BOM + for c in std::iter::once(0xFEFF).chain(args.encode_utf16()) { + // encode in little endian + out.push(c as u8); + out.push((c >> 8) as u8); + } + out + } else { + args.into_bytes() + }; + fs::write(&file, &bytes)?; + cmd2.arg(format!("@{}", file.display())); + info!("invoking linker {:?}", cmd2); + let output = cmd2.output(); + flush_linked_file(&output, out_filename)?; + return output; + + #[cfg(unix)] + fn flush_linked_file(_: &io::Result<Output>, _: &Path) -> io::Result<()> { + Ok(()) + } + + #[cfg(windows)] + fn flush_linked_file(command_output: &io::Result<Output>, out_filename: &Path) + -> io::Result<()> + { + // On Windows, under high I/O load, output buffers are sometimes not flushed, + // even long after process exit, causing nasty, non-reproducible output bugs. + // + // File::sync_all() calls FlushFileBuffers() down the line, which solves the problem. + // + // А full writeup of the original Chrome bug can be found at + // randomascii.wordpress.com/2018/02/25/compiler-bug-linker-bug-windows-kernel-bug/amp + + if let &Ok(ref out) = command_output { + if out.status.success() { + if let Ok(of) = fs::OpenOptions::new().write(true).open(out_filename) { + of.sync_all()?; + } + } + } + + Ok(()) + } + + #[cfg(unix)] + fn command_line_too_big(err: &io::Error) -> bool { + err.raw_os_error() == Some(::libc::E2BIG) + } + + #[cfg(windows)] + fn command_line_too_big(err: &io::Error) -> bool { + const ERROR_FILENAME_EXCED_RANGE: i32 = 206; + err.raw_os_error() == Some(ERROR_FILENAME_EXCED_RANGE) + } + + struct Escape<'a> { + arg: &'a str, + is_like_msvc: bool, + } + + impl<'a> fmt::Display for Escape<'a> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + if self.is_like_msvc { + // This is "documented" at + // https://msdn.microsoft.com/en-us/library/4xdcbak7.aspx + // + // Unfortunately there's not a great specification of the + // syntax I could find online (at least) but some local + // testing showed that this seemed sufficient-ish to catch + // at least a few edge cases. + write!(f, "\"")?; + for c in self.arg.chars() { + match c { + '"' => write!(f, "\\{}", c)?, + c => write!(f, "{}", c)?, + } + } + write!(f, "\"")?; + } else { + // This is documented at https://linux.die.net/man/1/ld, namely: + // + // > Options in file are separated by whitespace. A whitespace + // > character may be included in an option by surrounding the + // > entire option in either single or double quotes. Any + // > character (including a backslash) may be included by + // > prefixing the character to be included with a backslash. + // + // We put an argument on each line, so all we need to do is + // ensure the line is interpreted as one whole argument. + for c in self.arg.chars() { + match c { + '\\' | ' ' => write!(f, "\\{}", c)?, + c => write!(f, "{}", c)?, + } + } + } + Ok(()) + } + } +} + +// # Native library linking +// +// User-supplied library search paths (-L on the command line). These are +// the same paths used to find Rust crates, so some of them may have been +// added already by the previous crate linking code. This only allows them +// to be found at compile time so it is still entirely up to outside +// forces to make sure that library can be found at runtime. +// +// Also note that the native libraries linked here are only the ones located +// in the current crate. Upstream crates with native library dependencies +// may have their native library pulled in above. +pub fn add_local_native_libraries(cmd: &mut dyn Linker, + sess: &Session, + codegen_results: &CodegenResults) { + let filesearch = sess.target_filesearch(PathKind::All); + for search_path in filesearch.search_paths() { + match search_path.kind { + PathKind::Framework => { cmd.framework_path(&search_path.dir); } + _ => { cmd.include_path(&fix_windows_verbatim_for_gcc(&search_path.dir)); } + } + } + + let relevant_libs = codegen_results.crate_info.used_libraries.iter().filter(|l| { + relevant_lib(sess, l) + }); + + let search_path = archive_search_paths(sess); + for lib in relevant_libs { + let name = match lib.name { + Some(ref l) => l, + None => continue, + }; + match lib.kind { + NativeLibraryKind::NativeUnknown => cmd.link_dylib(&name.as_str()), + NativeLibraryKind::NativeFramework => cmd.link_framework(&name.as_str()), + NativeLibraryKind::NativeStaticNobundle => cmd.link_staticlib(&name.as_str()), + NativeLibraryKind::NativeStatic => cmd.link_whole_staticlib(&name.as_str(), + &search_path) + } + } +} + +// Link in all of our upstream crates' native dependencies. Remember that +// all of these upstream native dependencies are all non-static +// dependencies. We've got two cases then: +// +// 1. The upstream crate is an rlib. In this case we *must* link in the +// native dependency because the rlib is just an archive. +// +// 2. The upstream crate is a dylib. In order to use the dylib, we have to +// have the dependency present on the system somewhere. Thus, we don't +// gain a whole lot from not linking in the dynamic dependency to this +// crate as well. +// +// The use case for this is a little subtle. In theory the native +// dependencies of a crate are purely an implementation detail of the crate +// itself, but the problem arises with generic and inlined functions. If a +// generic function calls a native function, then the generic function must +// be instantiated in the target crate, meaning that the native symbol must +// also be resolved in the target crate. +pub fn add_upstream_native_libraries(cmd: &mut dyn Linker, + sess: &Session, + codegen_results: &CodegenResults, + crate_type: config::CrateType) { + // Be sure to use a topological sorting of crates because there may be + // interdependencies between native libraries. When passing -nodefaultlibs, + // for example, almost all native libraries depend on libc, so we have to + // make sure that's all the way at the right (liblibc is near the base of + // the dependency chain). + // + // This passes RequireStatic, but the actual requirement doesn't matter, + // we're just getting an ordering of crate numbers, we're not worried about + // the paths. + let formats = sess.dependency_formats.borrow(); + let data = formats.get(&crate_type).unwrap(); + + let crates = &codegen_results.crate_info.used_crates_static; + for &(cnum, _) in crates { + for lib in codegen_results.crate_info.native_libraries[&cnum].iter() { + let name = match lib.name { + Some(ref l) => l, + None => continue, + }; + if !relevant_lib(sess, &lib) { + continue + } + match lib.kind { + NativeLibraryKind::NativeUnknown => cmd.link_dylib(&name.as_str()), + NativeLibraryKind::NativeFramework => cmd.link_framework(&name.as_str()), + NativeLibraryKind::NativeStaticNobundle => { + // Link "static-nobundle" native libs only if the crate they originate from + // is being linked statically to the current crate. If it's linked dynamically + // or is an rlib already included via some other dylib crate, the symbols from + // native libs will have already been included in that dylib. + if data[cnum.as_usize() - 1] == Linkage::Static { + cmd.link_staticlib(&name.as_str()) + } + }, + // ignore statically included native libraries here as we've + // already included them when we included the rust library + // previously + NativeLibraryKind::NativeStatic => {} + } + } + } +} + +pub fn relevant_lib(sess: &Session, lib: &NativeLibrary) -> bool { + match lib.cfg { + Some(ref cfg) => syntax::attr::cfg_matches(cfg, &sess.parse_sess, None), + None => true, + } +} + +pub fn are_upstream_rust_objects_already_included(sess: &Session) -> bool { + match sess.lto() { + config::Lto::Fat => true, + config::Lto::Thin => { + // If we defer LTO to the linker, we haven't run LTO ourselves, so + // any upstream object files have not been copied yet. + !sess.opts.cg.linker_plugin_lto.enabled() + } + config::Lto::No | + config::Lto::ThinLocal => false, + } +} |