src/librustc_metadata/native_libs.rs

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