compiler/rustc_metadata/src/native_libs.rs

   1 use rustc_ast::{NestedMetaItem, CRATE_NODE_ID};
   2 use rustc_attr as attr;
   3 use rustc_data_structures::fx::FxHashSet;
   4 use rustc_hir as hir;
   5 use rustc_hir::def::DefKind;
   6 use rustc_middle::ty::{List, ParamEnv, ParamEnvAnd, Ty, TyCtxt};
   7 use rustc_session::config::CrateType;
   8 use rustc_session::cstore::{DllCallingConvention, DllImport, NativeLib, PeImportNameType};
   9 use rustc_session::parse::feature_err;
  10 use rustc_session::search_paths::PathKind;
  11 use rustc_session::utils::NativeLibKind;
  12 use rustc_session::Session;
  13 use rustc_span::symbol::{sym, Symbol};
  14 use rustc_target::spec::abi::Abi;
  15
  16 use crate::errors::{
  17     AsNeededCompatibility, BundleNeedsStatic, EmptyLinkName, EmptyRenamingTarget,
  18     FrameworkOnlyWindows, ImportNameTypeForm, ImportNameTypeRaw, ImportNameTypeX86,
  19     IncompatibleWasmLink, InvalidLinkModifier, LibFrameworkApple, LinkCfgForm,
  20     LinkCfgSinglePredicate, LinkFrameworkApple, LinkKindForm, LinkModifiersForm, LinkNameForm,
  21     LinkOrdinalRawDylib, LinkRequiresName, MissingNativeLibrary, MultipleCfgs,
  22     MultipleImportNameType, MultipleKindsInLink, MultipleLinkModifiers, MultipleModifiers,
  23     MultipleNamesInLink, MultipleRenamings, MultipleWasmImport, NoLinkModOverride, RawDylibNoNul,
  24     RenamingNoLink, UnexpectedLinkArg, UnknownImportNameType, UnknownLinkKind, UnknownLinkModifier,
  25     UnsupportedAbi, UnsupportedAbiI686, WasmImportForm, WholeArchiveNeedsStatic,
  26 };
  27
  28 use std::path::PathBuf;
  29
  30 pub fn find_native_static_library(
  31     name: &str,
  32     verbatim: bool,
  33     search_paths: &[PathBuf],
  34     sess: &Session,
  35 ) -> PathBuf {
  36     let formats = if verbatim {
  37         vec![("".into(), "".into())]
  38     } else {
  39         let os = (sess.target.staticlib_prefix.clone(), sess.target.staticlib_suffix.clone());
  40         // On Windows, static libraries sometimes show up as libfoo.a and other
  41         // times show up as foo.lib
  42         let unix = ("lib".into(), ".a".into());
  43         if os == unix { vec![os] } else { vec![os, unix] }
  44     };
  45
  46     for path in search_paths {
  47         for (prefix, suffix) in &formats {
  48             let test = path.join(format!("{}{}{}", prefix, name, suffix));
  49             if test.exists() {
  50                 return test;
  51             }
  52         }
  53     }
  54
  55     sess.emit_fatal(MissingNativeLibrary::new(name, verbatim));
  56 }
  57
  58 fn find_bundled_library(
  59     name: Option<Symbol>,
  60     verbatim: Option<bool>,
  61     kind: NativeLibKind,
  62     sess: &Session,
  63 ) -> Option<Symbol> {
  64     if sess.opts.unstable_opts.packed_bundled_libs &&
  65             sess.crate_types().iter().any(|ct| ct == &CrateType::Rlib || ct == &CrateType::Staticlib) &&
  66             let NativeLibKind::Static { bundle: Some(true) | None, .. } = kind {
  67         find_native_static_library(
  68             name.unwrap().as_str(),
  69             verbatim.unwrap_or(false),
  70             &sess.target_filesearch(PathKind::Native).search_path_dirs(),
  71             sess,
  72         ).file_name().and_then(|s| s.to_str()).map(Symbol::intern)
  73     } else {
  74         None
  75     }
  76 }
  77
  78 pub(crate) fn collect(tcx: TyCtxt<'_>) -> Vec<NativeLib> {
  79     let mut collector = Collector { tcx, libs: Vec::new() };
  80     for id in tcx.hir().items() {
  81         collector.process_item(id);
  82     }
  83     collector.process_command_line();
  84     collector.libs
  85 }
  86
  87 pub(crate) fn relevant_lib(sess: &Session, lib: &NativeLib) -> bool {
  88     match lib.cfg {
  89         Some(ref cfg) => attr::cfg_matches(cfg, &sess.parse_sess, CRATE_NODE_ID, None),
  90         None => true,
  91     }
  92 }
  93
  94 struct Collector<'tcx> {
  95     tcx: TyCtxt<'tcx>,
  96     libs: Vec<NativeLib>,
  97 }
  98
  99 impl<'tcx> Collector<'tcx> {
 100     fn process_item(&mut self, id: rustc_hir::ItemId) {
 101         if !matches!(self.tcx.def_kind(id.owner_id), DefKind::ForeignMod) {
 102             return;
 103         }
 104
 105         let it = self.tcx.hir().item(id);
 106         let hir::ItemKind::ForeignMod { abi, items: foreign_mod_items } = it.kind else {
 107             return;
 108         };
 109
 110         if abi == Abi::Rust || abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic {
 111             return;
 112         }
 113
 114         // Process all of the #[link(..)]-style arguments
 115         let sess = &self.tcx.sess;
 116         let features = self.tcx.features();
 117         for m in self.tcx.hir().attrs(it.hir_id()).iter().filter(|a| a.has_name(sym::link)) {
 118             let Some(items) = m.meta_item_list() else {
 119                 continue;
 120             };
 121
 122             let mut name = None;
 123             let mut kind = None;
 124             let mut modifiers = None;
 125             let mut cfg = None;
 126             let mut wasm_import_module = None;
 127             let mut import_name_type = None;
 128             for item in items.iter() {
 129                 match item.name_or_empty() {
 130                     sym::name => {
 131                         if name.is_some() {
 132                             sess.emit_err(MultipleNamesInLink { span: item.span() });
 133                             continue;
 134                         }
 135                         let Some(link_name) = item.value_str() else {
 136                             sess.emit_err(LinkNameForm { span: item.span() });
 137                             continue;
 138                         };
 139                         let span = item.name_value_literal_span().unwrap();
 140                         if link_name.is_empty() {
 141                             sess.emit_err(EmptyLinkName { span });
 142                         }
 143                         name = Some((link_name, span));
 144                     }
 145                     sym::kind => {
 146                         if kind.is_some() {
 147                             sess.emit_err(MultipleKindsInLink { span: item.span() });
 148                             continue;
 149                         }
 150                         let Some(link_kind) = item.value_str() else {
 151                             sess.emit_err(LinkKindForm { span: item.span() });
 152                             continue;
 153                         };
 154
 155                         let span = item.name_value_literal_span().unwrap();
 156                         let link_kind = match link_kind.as_str() {
 157                             "static" => NativeLibKind::Static { bundle: None, whole_archive: None },
 158                             "dylib" => NativeLibKind::Dylib { as_needed: None },
 159                             "framework" => {
 160                                 if !sess.target.is_like_osx {
 161                                     sess.emit_err(LinkFrameworkApple { span });
 162                                 }
 163                                 NativeLibKind::Framework { as_needed: None }
 164                             }
 165                             "raw-dylib" => {
 166                                 if !sess.target.is_like_windows {
 167                                     sess.emit_err(FrameworkOnlyWindows { span });
 168                                 } else if !features.raw_dylib && sess.target.arch == "x86" {
 169                                     feature_err(
 170                                         &sess.parse_sess,
 171                                         sym::raw_dylib,
 172                                         span,
 173                                         "link kind `raw-dylib` is unstable on x86",
 174                                     )
 175                                     .emit();
 176                                 }
 177                                 NativeLibKind::RawDylib
 178                             }
 179                             kind => {
 180                                 sess.emit_err(UnknownLinkKind { span, kind });
 181                                 continue;
 182                             }
 183                         };
 184                         kind = Some(link_kind);
 185                     }
 186                     sym::modifiers => {
 187                         if modifiers.is_some() {
 188                             sess.emit_err(MultipleLinkModifiers { span: item.span() });
 189                             continue;
 190                         }
 191                         let Some(link_modifiers) = item.value_str() else {
 192                             sess.emit_err(LinkModifiersForm { span: item.span() });
 193                             continue;
 194                         };
 195                         modifiers = Some((link_modifiers, item.name_value_literal_span().unwrap()));
 196                     }
 197                     sym::cfg => {
 198                         if cfg.is_some() {
 199                             sess.emit_err(MultipleCfgs { span: item.span() });
 200                             continue;
 201                         }
 202                         let Some(link_cfg) = item.meta_item_list() else {
 203                             sess.emit_err(LinkCfgForm { span: item.span() });
 204                             continue;
 205                         };
 206                         let [NestedMetaItem::MetaItem(link_cfg)] = link_cfg else {
 207                             sess.emit_err(LinkCfgSinglePredicate { span: item.span() });
 208                             continue;
 209                         };
 210                         if !features.link_cfg {
 211                             feature_err(
 212                                 &sess.parse_sess,
 213                                 sym::link_cfg,
 214                                 item.span(),
 215                                 "link cfg is unstable",
 216                             )
 217                             .emit();
 218                         }
 219                         cfg = Some(link_cfg.clone());
 220                     }
 221                     sym::wasm_import_module => {
 222                         if wasm_import_module.is_some() {
 223                             sess.emit_err(MultipleWasmImport { span: item.span() });
 224                             continue;
 225                         }
 226                         let Some(link_wasm_import_module) = item.value_str() else {
 227                             sess.emit_err(WasmImportForm { span: item.span() });
 228                             continue;
 229                         };
 230                         wasm_import_module = Some((link_wasm_import_module, item.span()));
 231                     }
 232                     sym::import_name_type => {
 233                         if import_name_type.is_some() {
 234                             sess.emit_err(MultipleImportNameType { span: item.span() });
 235                             continue;
 236                         }
 237                         let Some(link_import_name_type) = item.value_str() else {
 238                             sess.emit_err(ImportNameTypeForm { span: item.span() });
 239                             continue;
 240                         };
 241                         if self.tcx.sess.target.arch != "x86" {
 242                             sess.emit_err(ImportNameTypeX86 { span: item.span() });
 243                             continue;
 244                         }
 245
 246                         let link_import_name_type = match link_import_name_type.as_str() {
 247                             "decorated" => PeImportNameType::Decorated,
 248                             "noprefix" => PeImportNameType::NoPrefix,
 249                             "undecorated" => PeImportNameType::Undecorated,
 250                             import_name_type => {
 251                                 sess.emit_err(UnknownImportNameType {
 252                                     span: item.span(),
 253                                     import_name_type,
 254                                 });
 255                                 continue;
 256                             }
 257                         };
 258                         if !features.raw_dylib {
 259                             let span = item.name_value_literal_span().unwrap();
 260                             feature_err(
 261                                 &sess.parse_sess,
 262                                 sym::raw_dylib,
 263                                 span,
 264                                 "import name type is unstable",
 265                             )
 266                             .emit();
 267                         }
 268                         import_name_type = Some((link_import_name_type, item.span()));
 269                     }
 270                     _ => {
 271                         sess.emit_err(UnexpectedLinkArg { span: item.span() });
 272                     }
 273                 }
 274             }
 275
 276             // Do this outside the above loop so we don't depend on modifiers coming after kinds
 277             let mut verbatim = None;
 278             if let Some((modifiers, span)) = modifiers {
 279                 for modifier in modifiers.as_str().split(',') {
 280                     let (modifier, value) = match modifier.strip_prefix(&['+', '-']) {
 281                         Some(m) => (m, modifier.starts_with('+')),
 282                         None => {
 283                             sess.emit_err(InvalidLinkModifier { span });
 284                             continue;
 285                         }
 286                     };
 287
 288                     macro report_unstable_modifier($feature: ident) {
 289                         if !features.$feature {
 290                             feature_err(
 291                                 &sess.parse_sess,
 292                                 sym::$feature,
 293                                 span,
 294                                 &format!("linking modifier `{modifier}` is unstable"),
 295                             )
 296                             .emit();
 297                         }
 298                     }
 299                     let assign_modifier = |dst: &mut Option<bool>| {
 300                         if dst.is_some() {
 301                             sess.emit_err(MultipleModifiers { span, modifier });
 302                         } else {
 303                             *dst = Some(value);
 304                         }
 305                     };
 306                     match (modifier, &mut kind) {
 307                         ("bundle", Some(NativeLibKind::Static { bundle, .. })) => {
 308                             assign_modifier(bundle)
 309                         }
 310                         ("bundle", _) => {
 311                             sess.emit_err(BundleNeedsStatic { span });
 312                         }
 313
 314                         ("verbatim", _) => assign_modifier(&mut verbatim),
 315
 316                         ("whole-archive", Some(NativeLibKind::Static { whole_archive, .. })) => {
 317                             assign_modifier(whole_archive)
 318                         }
 319                         ("whole-archive", _) => {
 320                             sess.emit_err(WholeArchiveNeedsStatic { span });
 321                         }
 322
 323                         ("as-needed", Some(NativeLibKind::Dylib { as_needed }))
 324                         | ("as-needed", Some(NativeLibKind::Framework { as_needed })) => {
 325                             report_unstable_modifier!(native_link_modifiers_as_needed);
 326                             assign_modifier(as_needed)
 327                         }
 328                         ("as-needed", _) => {
 329                             sess.emit_err(AsNeededCompatibility { span });
 330                         }
 331
 332                         _ => {
 333                             sess.emit_err(UnknownLinkModifier { span, modifier });
 334                         }
 335                     }
 336                 }
 337             }
 338
 339             if let Some((_, span)) = wasm_import_module {
 340                 if name.is_some() || kind.is_some() || modifiers.is_some() || cfg.is_some() {
 341                     sess.emit_err(IncompatibleWasmLink { span });
 342                 }
 343             } else if name.is_none() {
 344                 sess.emit_err(LinkRequiresName { span: m.span });
 345             }
 346
 347             // Do this outside of the loop so that `import_name_type` can be specified before `kind`.
 348             if let Some((_, span)) = import_name_type {
 349                 if kind != Some(NativeLibKind::RawDylib) {
 350                     sess.emit_err(ImportNameTypeRaw { span });
 351                 }
 352             }
 353
 354             let dll_imports = match kind {
 355                 Some(NativeLibKind::RawDylib) => {
 356                     if let Some((name, span)) = name && name.as_str().contains('\0') {
 357                         sess.emit_err(RawDylibNoNul { span });
 358                     }
 359                     foreign_mod_items
 360                         .iter()
 361                         .map(|child_item| {
 362                             self.build_dll_import(
 363                                 abi,
 364                                 import_name_type.map(|(import_name_type, _)| import_name_type),
 365                                 child_item,
 366                             )
 367                         })
 368                         .collect()
 369                 }
 370                 _ => {
 371                     for child_item in foreign_mod_items {
 372                         if self.tcx.def_kind(child_item.id.owner_id).has_codegen_attrs()
 373                             && self
 374                                 .tcx
 375                                 .codegen_fn_attrs(child_item.id.owner_id)
 376                                 .link_ordinal
 377                                 .is_some()
 378                         {
 379                             let link_ordinal_attr = self
 380                                 .tcx
 381                                 .hir()
 382                                 .attrs(child_item.id.owner_id.into())
 383                                 .iter()
 384                                 .find(|a| a.has_name(sym::link_ordinal))
 385                                 .unwrap();
 386                             sess.emit_err(LinkOrdinalRawDylib { span: link_ordinal_attr.span });
 387                         }
 388                     }
 389
 390                     Vec::new()
 391                 }
 392             };
 393
 394             let name = name.map(|(name, _)| name);
 395             let kind = kind.unwrap_or(NativeLibKind::Unspecified);
 396             let filename = find_bundled_library(name, verbatim, kind, sess);
 397             self.libs.push(NativeLib {
 398                 name,
 399                 filename,
 400                 kind,
 401                 cfg,
 402                 foreign_module: Some(it.owner_id.to_def_id()),
 403                 wasm_import_module: wasm_import_module.map(|(name, _)| name),
 404                 verbatim,
 405                 dll_imports,
 406             });
 407         }
 408     }
 409
 410     // Process libs passed on the command line
 411     fn process_command_line(&mut self) {
 412         // First, check for errors
 413         let mut renames = FxHashSet::default();
 414         for lib in &self.tcx.sess.opts.libs {
 415             if let NativeLibKind::Framework { .. } = lib.kind && !self.tcx.sess.target.is_like_osx {
 416                 // Cannot check this when parsing options because the target is not yet available.
 417                 self.tcx.sess.emit_err(LibFrameworkApple);
 418             }
 419             if let Some(ref new_name) = lib.new_name {
 420                 let any_duplicate = self
 421                     .libs
 422                     .iter()
 423                     .filter_map(|lib| lib.name.as_ref())
 424                     .any(|n| n.as_str() == lib.name);
 425                 if new_name.is_empty() {
 426                     self.tcx.sess.emit_err(EmptyRenamingTarget { lib_name: &lib.name });
 427                 } else if !any_duplicate {
 428                     self.tcx.sess.emit_err(RenamingNoLink { lib_name: &lib.name });
 429                 } else if !renames.insert(&lib.name) {
 430                     self.tcx.sess.emit_err(MultipleRenamings { lib_name: &lib.name });
 431                 }
 432             }
 433         }
 434
 435         // Update kind and, optionally, the name of all native libraries
 436         // (there may be more than one) with the specified name.  If any
 437         // library is mentioned more than once, keep the latest mention
 438         // of it, so that any possible dependent libraries appear before
 439         // it.  (This ensures that the linker is able to see symbols from
 440         // all possible dependent libraries before linking in the library
 441         // in question.)
 442         for passed_lib in &self.tcx.sess.opts.libs {
 443             // If we've already added any native libraries with the same
 444             // name, they will be pulled out into `existing`, so that we
 445             // can move them to the end of the list below.
 446             let mut existing = self
 447                 .libs
 448                 .drain_filter(|lib| {
 449                     if let Some(lib_name) = lib.name {
 450                         if lib_name.as_str() == passed_lib.name {
 451                             // FIXME: This whole logic is questionable, whether modifiers are
 452                             // involved or not, library reordering and kind overriding without
 453                             // explicit `:rename` in particular.
 454                             if lib.has_modifiers() || passed_lib.has_modifiers() {
 455                                 match lib.foreign_module {
 456                                     Some(def_id) => self.tcx.sess.emit_err(NoLinkModOverride {
 457                                         span: Some(self.tcx.def_span(def_id)),
 458                                     }),
 459                                     None => {
 460                                         self.tcx.sess.emit_err(NoLinkModOverride { span: None })
 461                                     }
 462                                 };
 463                             }
 464                             if passed_lib.kind != NativeLibKind::Unspecified {
 465                                 lib.kind = passed_lib.kind;
 466                             }
 467                             if let Some(new_name) = &passed_lib.new_name {
 468                                 lib.name = Some(Symbol::intern(new_name));
 469                             }
 470                             lib.verbatim = passed_lib.verbatim;
 471                             return true;
 472                         }
 473                     }
 474                     false
 475                 })
 476                 .collect::<Vec<_>>();
 477             if existing.is_empty() {
 478                 // Add if not found
 479                 let new_name: Option<&str> = passed_lib.new_name.as_deref();
 480                 let name = Some(Symbol::intern(new_name.unwrap_or(&passed_lib.name)));
 481                 let sess = self.tcx.sess;
 482                 let filename =
 483                     find_bundled_library(name, passed_lib.verbatim, passed_lib.kind, sess);
 484                 self.libs.push(NativeLib {
 485                     name,
 486                     filename,
 487                     kind: passed_lib.kind,
 488                     cfg: None,
 489                     foreign_module: None,
 490                     wasm_import_module: None,
 491                     verbatim: passed_lib.verbatim,
 492                     dll_imports: Vec::new(),
 493                 });
 494             } else {
 495                 // Move all existing libraries with the same name to the
 496                 // end of the command line.
 497                 self.libs.append(&mut existing);
 498             }
 499         }
 500     }
 501
 502     fn i686_arg_list_size(&self, item: &hir::ForeignItemRef) -> usize {
 503         let argument_types: &List<Ty<'_>> = self.tcx.erase_late_bound_regions(
 504             self.tcx
 505                 .type_of(item.id.owner_id)
 506                 .fn_sig(self.tcx)
 507                 .inputs()
 508                 .map_bound(|slice| self.tcx.mk_type_list(slice.iter())),
 509         );
 510
 511         argument_types
 512             .iter()
 513             .map(|ty| {
 514                 let layout = self
 515                     .tcx
 516                     .layout_of(ParamEnvAnd { param_env: ParamEnv::empty(), value: ty })
 517                     .expect("layout")
 518                     .layout;
 519                 // In both stdcall and fastcall, we always round up the argument size to the
 520                 // nearest multiple of 4 bytes.
 521                 (layout.size().bytes_usize() + 3) & !3
 522             })
 523             .sum()
 524     }
 525
 526     fn build_dll_import(
 527         &self,
 528         abi: Abi,
 529         import_name_type: Option<PeImportNameType>,
 530         item: &hir::ForeignItemRef,
 531     ) -> DllImport {
 532         let calling_convention = if self.tcx.sess.target.arch == "x86" {
 533             match abi {
 534                 Abi::C { .. } | Abi::Cdecl { .. } => DllCallingConvention::C,
 535                 Abi::Stdcall { .. } | Abi::System { .. } => {
 536                     DllCallingConvention::Stdcall(self.i686_arg_list_size(item))
 537                 }
 538                 Abi::Fastcall { .. } => {
 539                     DllCallingConvention::Fastcall(self.i686_arg_list_size(item))
 540                 }
 541                 Abi::Vectorcall { .. } => {
 542                     DllCallingConvention::Vectorcall(self.i686_arg_list_size(item))
 543                 }
 544                 _ => {
 545                     self.tcx.sess.emit_fatal(UnsupportedAbiI686 { span: item.span });
 546                 }
 547             }
 548         } else {
 549             match abi {
 550                 Abi::C { .. } | Abi::Win64 { .. } | Abi::System { .. } => DllCallingConvention::C,
 551                 _ => {
 552                     self.tcx.sess.emit_fatal(UnsupportedAbi { span: item.span });
 553                 }
 554             }
 555         };
 556
 557         let codegen_fn_attrs = self.tcx.codegen_fn_attrs(item.id.owner_id);
 558         let import_name_type = codegen_fn_attrs
 559             .link_ordinal
 560             .map_or(import_name_type, |ord| Some(PeImportNameType::Ordinal(ord)));
 561
 562         DllImport {
 563             name: codegen_fn_attrs.link_name.unwrap_or(item.ident.name),
 564             import_name_type,
 565             calling_convention,
 566             span: item.span,
 567             is_fn: self.tcx.def_kind(item.id.owner_id).is_fn_like(),
 568         }
 569     }
 570 }