From 885024df25c1fa967e81ef0b495de844eb2890d8 Mon Sep 17 00:00:00 2001 From: Vadim Petrochenkov Date: Thu, 6 Jun 2024 19:57:36 +0300 Subject: [PATCH] linker: Link dylib crates by path --- compiler/rustc_codegen_ssa/src/back/link.rs | 42 ++---- compiler/rustc_codegen_ssa/src/back/linker.rs | 136 +++++++++++------- tests/run-make/dylib-soname/foo.rs | 1 + tests/run-make/dylib-soname/rmake.rs | 19 +++ 4 files changed, 113 insertions(+), 85 deletions(-) create mode 100644 tests/run-make/dylib-soname/foo.rs create mode 100644 tests/run-make/dylib-soname/rmake.rs diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs index d509e4ce56d5b..fae528ffac61a 100644 --- a/compiler/rustc_codegen_ssa/src/back/link.rs +++ b/compiler/rustc_codegen_ssa/src/back/link.rs @@ -2813,6 +2813,15 @@ fn rehome_sysroot_lib_dir(sess: &Session, lib_dir: &Path) -> PathBuf { } } +fn rehome_lib_path(sess: &Session, path: &Path) -> PathBuf { + if let Some(dir) = path.parent() { + let file_name = path.file_name().expect("library path has no file name component"); + rehome_sysroot_lib_dir(sess, dir).join(file_name) + } else { + fix_windows_verbatim_for_gcc(path) + } +} + // 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. @@ -2843,15 +2852,8 @@ fn add_static_crate( let src = &codegen_results.crate_info.used_crate_source[&cnum]; let cratepath = &src.rlib.as_ref().unwrap().0; - let mut link_upstream = |path: &Path| { - let rlib_path = if let Some(dir) = path.parent() { - let file_name = path.file_name().expect("rlib path has no file name path component"); - rehome_sysroot_lib_dir(sess, dir).join(file_name) - } else { - fix_windows_verbatim_for_gcc(path) - }; - cmd.link_staticlib_by_path(&rlib_path, false); - }; + let mut link_upstream = + |path: &Path| cmd.link_staticlib_by_path(&rehome_lib_path(sess, path), false); if !are_upstream_rust_objects_already_included(sess) || ignored_for_lto(sess, &codegen_results.crate_info, cnum) @@ -2915,27 +2917,7 @@ fn add_static_crate( // 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(); - // When producing a dll, the MSVC linker may not actually emit a - // `foo.lib` file if the dll doesn't actually export any symbols, so we - // check to see if the file is there and just omit linking to it if it's - // not present. - if sess.target.is_like_msvc && !cratepath.with_extension("dll.lib").exists() { - return; - } - if let Some(dir) = parent { - cmd.include_path(&rehome_sysroot_lib_dir(sess, dir)); - } - // "/name.dll -> name.dll" on windows-msvc - // "/name.dll -> name" on windows-gnu - // "/libname. -> name" elsewhere - let stem = if sess.target.is_like_msvc { cratepath.file_name() } else { cratepath.file_stem() }; - let stem = 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_dylib_by_name(&stem[prefix..], false, true); + cmd.link_dylib_by_path(&rehome_lib_path(sess, cratepath), true); } fn relevant_lib(sess: &Session, lib: &NativeLib) -> bool { diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs index a82478900b17f..8675fcc75d1c6 100644 --- a/compiler/rustc_codegen_ssa/src/back/linker.rs +++ b/compiler/rustc_codegen_ssa/src/back/linker.rs @@ -169,7 +169,12 @@ pub fn get_linker<'a>( pub trait Linker { fn cmd(&mut self) -> &mut Command; fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path); - fn link_dylib_by_name(&mut self, name: &str, verbatim: bool, as_needed: bool); + fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) { + bug!("dylib linked with unsupported linker") + } + fn link_dylib_by_path(&mut self, _path: &Path, _as_needed: bool) { + bug!("dylib linked with unsupported linker") + } fn link_framework_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) { bug!("framework linked with unsupported linker") } @@ -320,28 +325,53 @@ impl<'a> GccLinker<'a> { } } else { self.cmd.arg("-shared"); - if self.sess.target.is_like_windows { - // The output filename already contains `dll_suffix` so - // the resulting import library will have a name in the - // form of libfoo.dll.a - let implib_name = - out_filename.file_name().and_then(|file| file.to_str()).map(|file| { - format!( - "{}{}{}", - self.sess.target.staticlib_prefix, - file, - self.sess.target.staticlib_suffix - ) - }); - if let Some(implib_name) = implib_name { - let implib = out_filename.parent().map(|dir| dir.join(&implib_name)); - if let Some(implib) = implib { - self.linker_arg(&format!("--out-implib={}", (*implib).to_str().unwrap())); - } + if let Some(name) = out_filename.file_name() { + if self.sess.target.is_like_windows { + // The output filename already contains `dll_suffix` so + // the resulting import library will have a name in the + // form of libfoo.dll.a + let mut implib_name = OsString::from(&*self.sess.target.staticlib_prefix); + implib_name.push(name); + implib_name.push(&*self.sess.target.staticlib_suffix); + let mut out_implib = OsString::from("--out-implib="); + out_implib.push(out_filename.with_file_name(implib_name)); + self.linker_arg(out_implib); + } else { + // When dylibs are linked by a full path this value will get into `DT_NEEDED` + // instead of the full path, so the library can be later found in some other + // location than that specific path. + let mut soname = OsString::from("-soname="); + soname.push(name); + self.linker_arg(soname); } } } } + + fn with_as_needed(&mut self, as_needed: bool, f: impl FnOnce(&mut Self)) { + if !as_needed { + if self.sess.target.is_like_osx { + // FIXME(81490): ld64 doesn't support these flags but macOS 11 + // has -needed-l{} / -needed_library {} + // but we have no way to detect that here. + self.sess.dcx().emit_warn(errors::Ld64UnimplementedModifier); + } else if self.is_gnu && !self.sess.target.is_like_windows { + self.linker_arg("--no-as-needed"); + } else { + self.sess.dcx().emit_warn(errors::LinkerUnsupportedModifier); + } + } + + f(self); + + if !as_needed { + if self.sess.target.is_like_osx { + // See above FIXME comment + } else if self.is_gnu && !self.sess.target.is_like_windows { + self.linker_arg("--as-needed"); + } + } + } } impl<'a> Linker for GccLinker<'a> { @@ -443,27 +473,17 @@ impl<'a> Linker for GccLinker<'a> { // to the linker. return; } - if !as_needed { - if self.sess.target.is_like_osx { - // FIXME(81490): ld64 doesn't support these flags but macOS 11 - // has -needed-l{} / -needed_library {} - // but we have no way to detect that here. - self.sess.dcx().emit_warn(errors::Ld64UnimplementedModifier); - } else if self.is_gnu && !self.sess.target.is_like_windows { - self.linker_arg("--no-as-needed"); - } else { - self.sess.dcx().emit_warn(errors::LinkerUnsupportedModifier); - } - } self.hint_dynamic(); - self.cmd.arg(format!("-l{}{name}", if verbatim && self.is_gnu { ":" } else { "" },)); - if !as_needed { - if self.sess.target.is_like_osx { - // See above FIXME comment - } else if self.is_gnu && !self.sess.target.is_like_windows { - self.linker_arg("--as-needed"); - } - } + self.with_as_needed(as_needed, |this| { + this.cmd.arg(format!("-l{}{name}", if verbatim && this.is_gnu { ":" } else { "" })); + }); + } + + fn link_dylib_by_path(&mut self, path: &Path, as_needed: bool) { + self.hint_dynamic(); + self.with_as_needed(as_needed, |this| { + this.cmd.arg(path); + }) } fn link_framework_by_name(&mut self, name: &str, _verbatim: bool, as_needed: bool) { @@ -813,6 +833,15 @@ impl<'a> Linker for MsvcLinker<'a> { self.cmd.arg(format!("{}{}", name, if verbatim { "" } else { ".lib" })); } + fn link_dylib_by_path(&mut self, path: &Path, _as_needed: bool) { + // When producing a dll, MSVC linker may not emit an implib file if the dll doesn't export + // any symbols, so we skip linking if the implib file is not present. + let implib_path = path.with_extension("dll.lib"); + if implib_path.exists() { + self.cmd().arg(implib_path); + } + } + fn link_staticlib_by_name(&mut self, name: &str, verbatim: bool, whole_archive: bool) { let prefix = if whole_archive { "/WHOLEARCHIVE:" } else { "" }; let suffix = if verbatim { "" } else { ".lib" }; @@ -1039,6 +1068,10 @@ impl<'a> Linker for EmLinker<'a> { self.cmd.arg("-l").arg(name); } + fn link_dylib_by_path(&mut self, path: &Path, _as_needed: bool) { + self.cmd().arg(path); + } + fn link_staticlib_by_name(&mut self, name: &str, _verbatim: bool, _whole_archive: bool) { self.cmd.arg("-l").arg(name); } @@ -1212,6 +1245,10 @@ impl<'a> Linker for WasmLd<'a> { self.cmd.arg("-l").arg(name); } + fn link_dylib_by_path(&mut self, path: &Path, _as_needed: bool) { + self.cmd().arg(path); + } + fn link_staticlib_by_name(&mut self, name: &str, _verbatim: bool, whole_archive: bool) { if !whole_archive { self.cmd.arg("-l").arg(name); @@ -1355,10 +1392,6 @@ impl<'a> Linker for L4Bender<'a> { fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {} - fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) { - bug!("dylibs are not supported on L4Re"); - } - fn link_staticlib_by_name(&mut self, name: &str, _verbatim: bool, whole_archive: bool) { self.hint_static(); if !whole_archive { @@ -1537,6 +1570,11 @@ impl<'a> Linker for AixLinker<'a> { self.cmd.arg(format!("-l{name}")); } + fn link_dylib_by_path(&mut self, path: &Path, _as_needed: bool) { + self.hint_dynamic(); + self.cmd().arg(path); + } + fn link_staticlib_by_name(&mut self, name: &str, verbatim: bool, whole_archive: bool) { self.hint_static(); if !whole_archive { @@ -1738,10 +1776,6 @@ impl<'a> Linker for PtxLinker<'a> { fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {} - fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) { - panic!("external dylibs not supported") - } - fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) { panic!("staticlibs not supported") } @@ -1820,10 +1854,6 @@ impl<'a> Linker for LlbcLinker<'a> { fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {} - fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) { - panic!("external dylibs not supported") - } - fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) { panic!("staticlibs not supported") } @@ -1911,10 +1941,6 @@ impl<'a> Linker for BpfLinker<'a> { fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {} - fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) { - panic!("external dylibs not supported") - } - fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) { panic!("staticlibs not supported") } diff --git a/tests/run-make/dylib-soname/foo.rs b/tests/run-make/dylib-soname/foo.rs new file mode 100644 index 0000000000000..6833f39199943 --- /dev/null +++ b/tests/run-make/dylib-soname/foo.rs @@ -0,0 +1 @@ +pub fn something() {} diff --git a/tests/run-make/dylib-soname/rmake.rs b/tests/run-make/dylib-soname/rmake.rs new file mode 100644 index 0000000000000..a0215a6906e47 --- /dev/null +++ b/tests/run-make/dylib-soname/rmake.rs @@ -0,0 +1,19 @@ +// Checks that produced dylibs have a relative SONAME set, so they don't put "unmovable" full paths +// into DT_NEEDED when used by a full path. + +//@ only-linux +//@ ignore-cross-compile + +use run_make_support::regex::Regex; +use run_make_support::{cmd, run_in_tmpdir, rustc}; + +fn main() { + run_in_tmpdir(|| { + rustc().crate_name("foo").crate_type("dylib").input("foo.rs").run(); + cmd("readelf") + .arg("-d") + .arg("libfoo.so") + .run() + .assert_stdout_contains("Library soname: [libfoo.so]"); + }); +}