compiler/rustc_metadata/src/native_libs.rs

   1 use rustc_attr as attr;
   2 use rustc_data_structures::fx::FxHashSet;
   3 use rustc_errors::struct_span_err;
   4 use rustc_hir as hir;
   5 use rustc_hir::itemlikevisit::ItemLikeVisitor;
   6 use rustc_middle::middle::cstore::NativeLib;
   7 use rustc_middle::ty::TyCtxt;
   8 use rustc_session::parse::feature_err;
   9 use rustc_session::utils::NativeLibKind;
  10 use rustc_session::Session;
  11 use rustc_span::source_map::Span;
  12 use rustc_span::symbol::{kw, sym, Symbol};
  13 use rustc_target::spec::abi::Abi;
  14
  15 crate fn collect(tcx: TyCtxt<'_>) -> Vec<NativeLib> {
  16     let mut collector = Collector { tcx, libs: Vec::new() };
  17     tcx.hir().krate().visit_all_item_likes(&mut collector);
  18     collector.process_command_line();
  19     collector.libs
  20 }
  21
  22 crate fn relevant_lib(sess: &Session, lib: &NativeLib) -> bool {
  23     match lib.cfg {
  24         Some(ref cfg) => attr::cfg_matches(cfg, &sess.parse_sess, None),
  25         None => true,
  26     }
  27 }
  28
  29 struct Collector<'tcx> {
  30     tcx: TyCtxt<'tcx>,
  31     libs: Vec<NativeLib>,
  32 }
  33
  34 impl ItemLikeVisitor<'tcx> for Collector<'tcx> {
  35     fn visit_item(&mut self, it: &'tcx hir::Item<'tcx>) {
  36         let abi = match it.kind {
  37             hir::ItemKind::ForeignMod { abi, .. } => abi,
  38             _ => return,
  39         };
  40
  41         if abi == Abi::Rust || abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic {
  42             return;
  43         }
  44
  45         // Process all of the #[link(..)]-style arguments
  46         let sess = &self.tcx.sess;
  47         for m in it.attrs.iter().filter(|a| sess.check_name(a, sym::link)) {
  48             let items = match m.meta_item_list() {
  49                 Some(item) => item,
  50                 None => continue,
  51             };
  52             let mut lib = NativeLib {
  53                 name: None,
  54                 kind: NativeLibKind::Unspecified,
  55                 cfg: None,
  56                 foreign_module: Some(self.tcx.hir().local_def_id(it.hir_id).to_def_id()),
  57                 wasm_import_module: None,
  58             };
  59             let mut kind_specified = false;
  60
  61             for item in items.iter() {
  62                 if item.has_name(sym::kind) {
  63                     kind_specified = true;
  64                     let kind = match item.value_str() {
  65                         Some(name) => name,
  66                         None => continue, // skip like historical compilers
  67                     };
  68                     lib.kind = match &*kind.as_str() {
  69                         "static" => NativeLibKind::StaticBundle,
  70                         "static-nobundle" => NativeLibKind::StaticNoBundle,
  71                         "dylib" => NativeLibKind::Dylib,
  72                         "framework" => NativeLibKind::Framework,
  73                         "raw-dylib" => NativeLibKind::RawDylib,
  74                         k => {
  75                             struct_span_err!(sess, item.span(), E0458, "unknown kind: `{}`", k)
  76                                 .span_label(item.span(), "unknown kind")
  77                                 .span_label(m.span, "")
  78                                 .emit();
  79                             NativeLibKind::Unspecified
  80                         }
  81                     };
  82                 } else if item.has_name(sym::name) {
  83                     lib.name = item.value_str();
  84                 } else if item.has_name(sym::cfg) {
  85                     let cfg = match item.meta_item_list() {
  86                         Some(list) => list,
  87                         None => continue, // skip like historical compilers
  88                     };
  89                     if cfg.is_empty() {
  90                         sess.span_err(item.span(), "`cfg()` must have an argument");
  91                     } else if let cfg @ Some(..) = cfg[0].meta_item() {
  92                         lib.cfg = cfg.cloned();
  93                     } else {
  94                         sess.span_err(cfg[0].span(), "invalid argument for `cfg(..)`");
  95                     }
  96                 } else if item.has_name(sym::wasm_import_module) {
  97                     match item.value_str() {
  98                         Some(s) => lib.wasm_import_module = Some(s),
  99                         None => {
 100                             let msg = "must be of the form `#[link(wasm_import_module = \"...\")]`";
 101                             sess.span_err(item.span(), msg);
 102                         }
 103                     }
 104                 } else {
 105                     // currently, like past compilers, ignore unknown
 106                     // directives here.
 107                 }
 108             }
 109
 110             // In general we require #[link(name = "...")] but we allow
 111             // #[link(wasm_import_module = "...")] without the `name`.
 112             let requires_name = kind_specified || lib.wasm_import_module.is_none();
 113             if lib.name.is_none() && requires_name {
 114                 struct_span_err!(
 115                     sess,
 116                     m.span,
 117                     E0459,
 118                     "`#[link(...)]` specified without \
 119                                   `name = \"foo\"`"
 120                 )
 121                 .span_label(m.span, "missing `name` argument")
 122                 .emit();
 123             }
 124             self.register_native_lib(Some(m.span), lib);
 125         }
 126     }
 127
 128     fn visit_trait_item(&mut self, _it: &'tcx hir::TraitItem<'tcx>) {}
 129     fn visit_impl_item(&mut self, _it: &'tcx hir::ImplItem<'tcx>) {}
 130     fn visit_foreign_item(&mut self, _it: &'tcx hir::ForeignItem<'tcx>) {}
 131 }
 132
 133 impl Collector<'tcx> {
 134     fn register_native_lib(&mut self, span: Option<Span>, lib: NativeLib) {
 135         if lib.name.as_ref().map_or(false, |&s| s == kw::Empty) {
 136             match span {
 137                 Some(span) => {
 138                     struct_span_err!(
 139                         self.tcx.sess,
 140                         span,
 141                         E0454,
 142                         "`#[link(name = \"\")]` given with empty name"
 143                     )
 144                     .span_label(span, "empty name given")
 145                     .emit();
 146                 }
 147                 None => {
 148                     self.tcx.sess.err("empty library name given via `-l`");
 149                 }
 150             }
 151             return;
 152         }
 153         let is_osx = self.tcx.sess.target.is_like_osx;
 154         if lib.kind == NativeLibKind::Framework && !is_osx {
 155             let msg = "native frameworks are only available on macOS targets";
 156             match span {
 157                 Some(span) => struct_span_err!(self.tcx.sess, span, E0455, "{}", msg).emit(),
 158                 None => self.tcx.sess.err(msg),
 159             }
 160         }
 161         if lib.cfg.is_some() && !self.tcx.features().link_cfg {
 162             feature_err(
 163                 &self.tcx.sess.parse_sess,
 164                 sym::link_cfg,
 165                 span.unwrap(),
 166                 "kind=\"link_cfg\" is unstable",
 167             )
 168             .emit();
 169         }
 170         if lib.kind == NativeLibKind::StaticNoBundle && !self.tcx.features().static_nobundle {
 171             feature_err(
 172                 &self.tcx.sess.parse_sess,
 173                 sym::static_nobundle,
 174                 span.unwrap_or(rustc_span::DUMMY_SP),
 175                 "kind=\"static-nobundle\" is unstable",
 176             )
 177             .emit();
 178         }
 179         if lib.kind == NativeLibKind::RawDylib && !self.tcx.features().raw_dylib {
 180             feature_err(
 181                 &self.tcx.sess.parse_sess,
 182                 sym::raw_dylib,
 183                 span.unwrap_or(rustc_span::DUMMY_SP),
 184                 "kind=\"raw-dylib\" is unstable",
 185             )
 186             .emit();
 187         }
 188         self.libs.push(lib);
 189     }
 190
 191     // Process libs passed on the command line
 192     fn process_command_line(&mut self) {
 193         // First, check for errors
 194         let mut renames = FxHashSet::default();
 195         for (name, new_name, _) in &self.tcx.sess.opts.libs {
 196             if let Some(ref new_name) = new_name {
 197                 let any_duplicate = self
 198                     .libs
 199                     .iter()
 200                     .filter_map(|lib| lib.name.as_ref())
 201                     .any(|n| &n.as_str() == name);
 202                 if new_name.is_empty() {
 203                     self.tcx.sess.err(&format!(
 204                         "an empty renaming target was specified for library `{}`",
 205                         name
 206                     ));
 207                 } else if !any_duplicate {
 208                     self.tcx.sess.err(&format!(
 209                         "renaming of the library `{}` was specified, \
 210                                                 however this crate contains no `#[link(...)]` \
 211                                                 attributes referencing this library.",
 212                         name
 213                     ));
 214                 } else if !renames.insert(name) {
 215                     self.tcx.sess.err(&format!(
 216                         "multiple renamings were \
 217                                                 specified for library `{}` .",
 218                         name
 219                     ));
 220                 }
 221             }
 222         }
 223
 224         // Update kind and, optionally, the name of all native libraries
 225         // (there may be more than one) with the specified name.  If any
 226         // library is mentioned more than once, keep the latest mention
 227         // of it, so that any possible dependent libraries appear before
 228         // it.  (This ensures that the linker is able to see symbols from
 229         // all possible dependent libraries before linking in the library
 230         // in question.)
 231         for &(ref name, ref new_name, kind) in &self.tcx.sess.opts.libs {
 232             // If we've already added any native libraries with the same
 233             // name, they will be pulled out into `existing`, so that we
 234             // can move them to the end of the list below.
 235             let mut existing = self
 236                 .libs
 237                 .drain_filter(|lib| {
 238                     if let Some(lib_name) = lib.name {
 239                         if lib_name.as_str() == *name {
 240                             if kind != NativeLibKind::Unspecified {
 241                                 lib.kind = kind;
 242                             }
 243                             if let Some(new_name) = new_name {
 244                                 lib.name = Some(Symbol::intern(new_name));
 245                             }
 246                             return true;
 247                         }
 248                     }
 249                     false
 250                 })
 251                 .collect::<Vec<_>>();
 252             if existing.is_empty() {
 253                 // Add if not found
 254                 let new_name = new_name.as_ref().map(|s| &**s); // &Option<String> -> Option<&str>
 255                 let lib = NativeLib {
 256                     name: Some(Symbol::intern(new_name.unwrap_or(name))),
 257                     kind,
 258                     cfg: None,
 259                     foreign_module: None,
 260                     wasm_import_module: None,
 261                 };
 262                 self.register_native_lib(None, lib);
 263             } else {
 264                 // Move all existing libraries with the same name to the
 265                 // end of the command line.
 266                 self.libs.append(&mut existing);
 267             }
 268         }
 269     }
 270 }