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Stabilize native library modifier syntax and the whole-archive modifier specifically

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This commit is contained in:
Vadim Petrochenkov 2022-02-11 15:08:35 +08:00
parent bb5c437a2c
commit 1004783ef9
33 changed files with 269 additions and 164 deletions
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101
compiler/rustc_codegen_ssa/src/back/link.rs
View file

@ -1844,7 +1844,7 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>(
// This change is somewhat breaking in practice due to local static libraries being linked
// as whole-archive (#85144), so removing whole-archive may be a pre-requisite.
if sess.opts.debugging_opts.link_native_libraries {
add_local_native_libraries(cmd, sess, codegen_results);
add_local_native_libraries(cmd, sess, codegen_results, crate_type);
}
// Upstream rust libraries and their nobundle static libraries
@ -2016,6 +2016,16 @@ fn add_order_independent_options(
add_rpath_args(cmd, sess, codegen_results, out_filename);
}
// A dylib may reexport symbols from the linked rlib or native static library.
// Even if some symbol is reexported it's still not necessarily counted as used and may be
// dropped, at least with `ld`-like ELF linkers. So we have to link some rlibs and static
// libraries as whole-archive to avoid losing reexported symbols.
// FIXME: Find a way to mark reexported symbols as used and avoid this use of whole-archive.
fn default_to_whole_archive(sess: &Session, crate_type: CrateType, cmd: &dyn Linker) -> bool {
crate_type == CrateType::Dylib
&& !(sess.target.limit_rdylib_exports && cmd.exported_symbol_means_used_symbol())
}
/// # Native library linking
///
/// User-supplied library search paths (-L on the command line). These are the same paths used to
@ -2029,6 +2039,7 @@ fn add_local_native_libraries(
cmd: &mut dyn Linker,
sess: &Session,
codegen_results: &CodegenResults,
crate_type: CrateType,
) {
let filesearch = sess.target_filesearch(PathKind::All);
for search_path in filesearch.search_paths() {
@ -2046,14 +2057,18 @@ fn add_local_native_libraries(
codegen_results.crate_info.used_libraries.iter().filter(|l| relevant_lib(sess, l));
let search_path = OnceCell::new();
let mut last = (NativeLibKind::Unspecified, None);
let mut last = (None, NativeLibKind::Unspecified, None);
for lib in relevant_libs {
let Some(name) = lib.name else {
continue;
};
// Skip if this library is the same as the last.
last = if (lib.kind, lib.name) == last { continue } else { (lib.kind, lib.name) };
last = if (lib.name, lib.kind, lib.verbatim) == last {
continue;
} else {
(lib.name, lib.kind, lib.verbatim)
};
let verbatim = lib.verbatim.unwrap_or(false);
match lib.kind {
@ -2064,15 +2079,19 @@ fn add_local_native_libraries(
NativeLibKind::Framework { as_needed } => {
cmd.link_framework(name, as_needed.unwrap_or(true))
}
NativeLibKind::Static { bundle: None | Some(true), .. }
| NativeLibKind::Static { whole_archive: Some(true), .. } => {
cmd.link_whole_staticlib(
name,
verbatim,
&search_path.get_or_init(|| archive_search_paths(sess)),
);
NativeLibKind::Static { whole_archive, .. } => {
if whole_archive == Some(true)
|| (whole_archive == None && default_to_whole_archive(sess, crate_type, cmd))
{
cmd.link_whole_staticlib(
name,
verbatim,
&search_path.get_or_init(|| archive_search_paths(sess)),
);
} else {
cmd.link_staticlib(name, verbatim)
}
}
NativeLibKind::Static { .. } => cmd.link_staticlib(name, verbatim),
NativeLibKind::RawDylib => {
// FIXME(#58713): Proper handling for raw dylibs.
bug!("raw_dylib feature not yet implemented");
@ -2197,34 +2216,37 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
// external build system already has the native dependencies defined, and it
// will provide them to the linker itself.
if sess.opts.debugging_opts.link_native_libraries {
let mut last = None;
let mut last = (None, NativeLibKind::Unspecified, None);
for lib in &codegen_results.crate_info.native_libraries[&cnum] {
let Some(name) = lib.name else {
continue;
};
if !relevant_lib(sess, lib) {
// Skip libraries if they are disabled by `#[link(cfg=...)]`
continue;
}
// Skip if this library is the same as the last.
if last == lib.name {
last = if (lib.name, lib.kind, lib.verbatim) == last {
continue;
}
} else {
(lib.name, lib.kind, lib.verbatim)
};
if let Some(static_lib_name) = lib.name {
if let NativeLibKind::Static { bundle: Some(false), whole_archive } =
lib.kind
if let NativeLibKind::Static { bundle: Some(false), whole_archive } =
lib.kind
{
let verbatim = lib.verbatim.unwrap_or(false);
if whole_archive == Some(true)
|| (whole_archive == None
&& default_to_whole_archive(sess, crate_type, cmd))
{
let verbatim = lib.verbatim.unwrap_or(false);
if whole_archive == Some(true) {
cmd.link_whole_staticlib(
static_lib_name,
verbatim,
search_path.get_or_init(|| archive_search_paths(sess)),
);
} else {
cmd.link_staticlib(static_lib_name, verbatim);
}
last = lib.name;
cmd.link_whole_staticlib(
name,
verbatim,
search_path.get_or_init(|| archive_search_paths(sess)),
);
} else {
cmd.link_staticlib(name, verbatim);
}
}
}
@ -2282,15 +2304,10 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
let cratepath = &src.rlib.as_ref().unwrap().0;
let mut link_upstream = |path: &Path| {
// 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.
// We don't want to include the whole compiler-builtins crate (e.g., compiler-rt)
// regardless of the default because it'll get repeatedly linked anyway.
let path = fix_windows_verbatim_for_gcc(path);
if crate_type == CrateType::Dylib
if default_to_whole_archive(sess, crate_type, cmd)
&& codegen_results.crate_info.compiler_builtins != Some(cnum)
{
cmd.link_whole_rlib(&path);
@ -2401,7 +2418,7 @@ fn add_upstream_native_libraries(
sess: &Session,
codegen_results: &CodegenResults,
) {
let mut last = (NativeLibKind::Unspecified, None);
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 {
@ -2412,7 +2429,11 @@ fn add_upstream_native_libraries(
}
// Skip if this library is the same as the last.
last = if (lib.kind, lib.name) == last { continue } else { (lib.kind, lib.name) };
last = if (lib.name, lib.kind, lib.verbatim) == last {
continue;
} else {
(lib.name, lib.kind, lib.verbatim)
};
let verbatim = lib.verbatim.unwrap_or(false);
match lib.kind {

11
compiler/rustc_codegen_ssa/src/back/linker.rs
View file

@ -186,6 +186,9 @@ pub trait Linker {
fn no_crt_objects(&mut self);
fn no_default_libraries(&mut self);
fn export_symbols(&mut self, tmpdir: &Path, crate_type: CrateType, symbols: &[String]);
fn exported_symbol_means_used_symbol(&self) -> bool {
true
}
fn subsystem(&mut self, subsystem: &str);
fn group_start(&mut self);
fn group_end(&mut self);
@ -724,6 +727,10 @@ impl<'a> Linker for GccLinker<'a> {
}
}
fn exported_symbol_means_used_symbol(&self) -> bool {
self.sess.target.is_like_windows || self.sess.target.is_like_osx
}
fn subsystem(&mut self, subsystem: &str) {
self.linker_arg("--subsystem");
self.linker_arg(&subsystem);
@ -1471,6 +1478,10 @@ impl<'a> Linker for L4Bender<'a> {
return;
}
fn exported_symbol_means_used_symbol(&self) -> bool {
false
}
fn subsystem(&mut self, subsystem: &str) {
self.cmd.arg(&format!("--subsystem {}", subsystem));
}