support link modifier as-needed for raw-dylib-elf

compiler/rustc_attr_parsing/messages.ftl

@@ -1,5 +1,5 @@
 attr_parsing_as_needed_compatibility =
- linking modifier `as-needed` is only compatible with `dylib` and `framework` linking kinds
+ linking modifier `as-needed` is only compatible with `dylib`, `framework` and `raw-dylib` linking kinds
 
 attr_parsing_bundle_needs_static =
  linking modifier `bundle` is only compatible with `static` linking kind

compiler/rustc_attr_parsing/src/attributes/link_attrs.rs

@@ -180,7 +180,8 @@ impl<S: Stage> CombineAttributeParser<S> for LinkParser {
  }
 
  (sym::as_dash_needed, Some(NativeLibKind::Dylib { as_needed }))
- | (sym::as_dash_needed, Some(NativeLibKind::Framework { as_needed })) => {
+ | (sym::as_dash_needed, Some(NativeLibKind::Framework { as_needed }))
+ | (sym::as_dash_needed, Some(NativeLibKind::RawDylib { as_needed })) => {
  report_unstable_modifier!(native_link_modifiers_as_needed);
  assign_modifier(as_needed)
  }
@@ -219,12 +220,12 @@ impl<S: Stage> CombineAttributeParser<S> for LinkParser {
 
  // Do this outside of the loop so that `import_name_type` can be specified before `kind`.
  if let Some((_, span)) = import_name_type {
- if kind != Some(NativeLibKind::RawDylib) {
+ if !matches!(kind, Some(NativeLibKind::RawDylib { .. })) {
  cx.emit_err(ImportNameTypeRaw { span });
  }
  }
 
- if let Some(NativeLibKind::RawDylib) = kind
+ if let Some(NativeLibKind::RawDylib { .. }) = kind
  && name.as_str().contains('\0')
  {
  cx.emit_err(RawDylibNoNul { span: name_span });
@@ -315,7 +316,7 @@ impl LinkParser {
  cx.emit_err(RawDylibOnlyWindows { span: nv.value_span });
  }
 
- NativeLibKind::RawDylib
+ NativeLibKind::RawDylib { as_needed: None }
  }
  sym::link_dash_arg => {
  if !features.link_arg_attribute() {

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1490,7 +1490,7 @@ fn print_native_static_libs(
  NativeLibKind::Static { bundle: None | Some(true), .. }
  | NativeLibKind::LinkArg
  | NativeLibKind::WasmImportModule
- | NativeLibKind::RawDylib => None,
+ | NativeLibKind::RawDylib { .. } => None,
  }
  })
  // deduplication of consecutive repeated libraries, see rust-lang/rust#113209
@@ -2364,13 +2364,13 @@ fn linker_with_args(
  cmd.add_object(&output_path);
  }
  } else {
- for link_path in raw_dylib::create_raw_dylib_elf_stub_shared_objects(
+ for (link_path, as_needed) in raw_dylib::create_raw_dylib_elf_stub_shared_objects(
  sess,
  codegen_results.crate_info.used_libraries.iter(),
  &raw_dylib_dir,
  ) {
  // Always use verbatim linkage, see comments in create_raw_dylib_elf_stub_shared_objects.
- cmd.link_dylib_by_name(&link_path, true, false);
+ cmd.link_dylib_by_name(&link_path, true, as_needed);
  }
  }
  // As with add_upstream_native_libraries, we need to add the upstream raw-dylib symbols in case
@@ -2411,13 +2411,13 @@ fn linker_with_args(
  cmd.add_object(&output_path);
  }
  } else {
- for link_path in raw_dylib::create_raw_dylib_elf_stub_shared_objects(
+ for (link_path, as_needed) in raw_dylib::create_raw_dylib_elf_stub_shared_objects(
  sess,
  native_libraries_from_nonstatics,
  &raw_dylib_dir,
  ) {
  // Always use verbatim linkage, see comments in create_raw_dylib_elf_stub_shared_objects.
- cmd.link_dylib_by_name(&link_path, true, false);
+ cmd.link_dylib_by_name(&link_path, true, as_needed);
  }
  }
 
@@ -2726,7 +2726,7 @@ fn add_native_libs_from_crate(
  cmd.link_framework_by_name(name, verbatim, as_needed.unwrap_or(true))
  }
  }
- NativeLibKind::RawDylib => {
+ NativeLibKind::RawDylib { as_needed: _ } => {
  // Handled separately in `linker_with_args`.
  }
  NativeLibKind::WasmImportModule => {}

compiler/rustc_codegen_ssa/src/back/link/raw_dylib.rs

@@ -31,7 +31,7 @@ fn collate_raw_dylibs_windows<'a>(
  let mut dylib_table = FxIndexMap::<String, FxIndexMap<Symbol, &DllImport>>::default();
 
  for lib in used_libraries {
- if lib.kind == NativeLibKind::RawDylib {
+ if let NativeLibKind::RawDylib { .. } = lib.kind {
  let ext = if lib.verbatim { "" } else { ".dll" };
  let name = format!("{}{}", lib.name, ext);
  let imports = dylib_table.entry(name.clone()).or_default();
@@ -128,12 +128,12 @@ pub(super) fn create_raw_dylib_dll_import_libs<'a>(
 fn collate_raw_dylibs_elf<'a>(
  sess: &Session,
  used_libraries: impl IntoIterator<Item = &'a NativeLib>,
-) -> Vec<(String, Vec<DllImport>)> {
+) -> Vec<(String, Vec<DllImport>, bool)> {
  // Use index maps to preserve original order of imports and libraries.
- let mut dylib_table = FxIndexMap::<String, FxIndexMap<Symbol, &DllImport>>::default();
+ let mut dylib_table = FxIndexMap::<String, (FxIndexMap<Symbol, &DllImport>, bool)>::default();
 
  for lib in used_libraries {
- if lib.kind == NativeLibKind::RawDylib {
+ if let NativeLibKind::RawDylib { as_needed } = lib.kind {
  let filename = if lib.verbatim {
  lib.name.as_str().to_owned()
  } else {
@@ -142,17 +142,19 @@ fn collate_raw_dylibs_elf<'a>(
  format!("{prefix}{}{ext}", lib.name)
  };
 
- let imports = dylib_table.entry(filename.clone()).or_default();
+ let (stub_imports, stub_as_needed) =
+ dylib_table.entry(filename.clone()).or_insert((Default::default(), true));
  for import in &lib.dll_imports {
- imports.insert(import.name, import);
+ stub_imports.insert(import.name, import);
  }
+ *stub_as_needed = *stub_as_needed && as_needed.unwrap_or(true);
  }
  }
  sess.dcx().abort_if_errors();
  dylib_table
  .into_iter()
- .map(|(name, imports)| {
- (name, imports.into_iter().map(|(_, import)| import.clone()).collect())
+ .map(|(name, (imports, as_needed))| {
+ (name, imports.into_iter().map(|(_, import)| import.clone()).collect(), as_needed)
  })
  .collect()
 }
@@ -161,10 +163,10 @@ pub(super) fn create_raw_dylib_elf_stub_shared_objects<'a>(
  sess: &Session,
  used_libraries: impl IntoIterator<Item = &'a NativeLib>,
  raw_dylib_so_dir: &Path,
-) -> Vec<String> {
+) -> Vec<(String, bool)> {
  collate_raw_dylibs_elf(sess, used_libraries)
  .into_iter()
- .map(|(load_filename, raw_dylib_imports)| {
+ .map(|(load_filename, raw_dylib_imports, as_needed)| {
  use std::hash::Hash;
 
  // `load_filename` is the *target/loader* filename that will end up in NEEDED.
@@ -205,7 +207,7 @@ pub(super) fn create_raw_dylib_elf_stub_shared_objects<'a>(
  });
  };
 
- temporary_lib_name
+ (temporary_lib_name, as_needed)
  })
  .collect()
 }

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -309,7 +309,10 @@ pub enum NativeLibKind {
  },
  /// Dynamic library (e.g. `foo.dll` on Windows) without a corresponding import library.
  /// On Linux, it refers to a generated shared library stub.
- RawDylib,
+ RawDylib {
+ /// Whether the dynamic library will be linked only if it satisfies some undefined symbols
+ as_needed: Option<bool>,
+ },
  /// A macOS-specific kind of dynamic libraries.
  Framework {
  /// Whether the framework will be linked only if it satisfies some undefined symbols
@@ -332,11 +335,10 @@ impl NativeLibKind {
  NativeLibKind::Static { bundle, whole_archive } => {
  bundle.is_some() || whole_archive.is_some()
  }
- NativeLibKind::Dylib { as_needed } | NativeLibKind::Framework { as_needed } => {
- as_needed.is_some()
- }
- NativeLibKind::RawDylib
- | NativeLibKind::Unspecified
+ NativeLibKind::Dylib { as_needed }
+ | NativeLibKind::Framework { as_needed }
+ | NativeLibKind::RawDylib { as_needed } => as_needed.is_some(),
+ NativeLibKind::Unspecified
  | NativeLibKind::LinkArg
  | NativeLibKind::WasmImportModule => false,
  }
@@ -349,7 +351,9 @@ impl NativeLibKind {
  pub fn is_dllimport(&self) -> bool {
  matches!(
  self,
- NativeLibKind::Dylib { .. } | NativeLibKind::RawDylib | NativeLibKind::Unspecified
+ NativeLibKind::Dylib { .. }
+ | NativeLibKind::RawDylib { .. }
+ | NativeLibKind::Unspecified
  )
  }
 }

compiler/rustc_metadata/src/native_libs.rs

@@ -218,7 +218,7 @@ impl<'tcx> Collector<'tcx> {
  .flatten()
  {
  let dll_imports = match attr.kind {
- NativeLibKind::RawDylib => foreign_items
+ NativeLibKind::RawDylib { .. } => foreign_items
  .iter()
  .map(|&child_item| {
  self.build_dll_import(

compiler/rustc_session/src/config/native_libs.rs

@@ -135,7 +135,8 @@ fn parse_and_apply_modifier(cx: &ParseNativeLibCx<'_>, modifier: &str, native_li
  ),
 
  ("as-needed", NativeLibKind::Dylib { as_needed })
- | ("as-needed", NativeLibKind::Framework { as_needed }) => {
+ | ("as-needed", NativeLibKind::Framework { as_needed })
+ | ("as-needed", NativeLibKind::RawDylib { as_needed }) => {
  cx.on_unstable_value(
  "linking modifier `as-needed` is unstable",
  ", the `-Z unstable-options` flag must also be passed to use it",

tests/ui/linkage-attr/raw-dylib/elf/as_needed.rs

@@ -0,0 +1,43 @@
+//@ only-elf
+//@ needs-dynamic-linking
+
+//@ only-gnu
+//@ only-x86_64
+//@ revisions: as_needed no_as_needed no_modifier merge_1 merge_2 merge_3 merge_4
+
+//@ [as_needed] run-pass
+//@ [no_as_needed] run-fail
+//@ [no_modifier] run-pass
+//@ [merge_1] run-fail
+//@ [merge_2] run-fail
+//@ [merge_3] run-fail
+//@ [merge_4] run-pass
+
+#![allow(incomplete_features)]
+#![feature(raw_dylib_elf)]
+#![feature(native_link_modifiers_as_needed)]
+
+#[cfg_attr(
+ as_needed,
+ link(name = "taiqannf1y28z2rw", kind = "raw-dylib", modifiers = "+as-needed")
+)]
+#[cfg_attr(
+ no_as_needed,
+ link(name = "taiqannf1y28z2rw", kind = "raw-dylib", modifiers = "-as-needed")
+)]
+#[cfg_attr(no_modifier, link(name = "taiqannf1y28z2rw", kind = "raw-dylib"))]
+unsafe extern "C" {}
+
+#[cfg_attr(merge_1, link(name = "k9nm7qxoa79bg7e6", kind = "raw-dylib", modifiers = "+as-needed"))]
+#[cfg_attr(merge_2, link(name = "k9nm7qxoa79bg7e6", kind = "raw-dylib", modifiers = "-as-needed"))]
+#[cfg_attr(merge_3, link(name = "k9nm7qxoa79bg7e6", kind = "raw-dylib", modifiers = "-as-needed"))]
+#[cfg_attr(merge_4, link(name = "k9nm7qxoa79bg7e6", kind = "raw-dylib", modifiers = "+as-needed"))]
+unsafe extern "C" {}
+
+#[cfg_attr(merge_1, link(name = "k9nm7qxoa79bg7e6", kind = "raw-dylib", modifiers = "-as-needed"))]
+#[cfg_attr(merge_2, link(name = "k9nm7qxoa79bg7e6", kind = "raw-dylib", modifiers = "+as-needed"))]
+#[cfg_attr(merge_3, link(name = "k9nm7qxoa79bg7e6", kind = "raw-dylib", modifiers = "-as-needed"))]
+#[cfg_attr(merge_4, link(name = "k9nm7qxoa79bg7e6", kind = "raw-dylib", modifiers = "+as-needed"))]
+unsafe extern "C" {}
+
+fn main() {}