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::Symbol;
  12 use syntax::{span_err, struct_span_err};
  13
  14 pub fn collect<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> 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<'a, 'tcx: 'a> {
  32     tcx: TyCtxt<'a, 'tcx, 'tcx>,
  33     libs: Vec<NativeLibrary>,
  34 }
  35
  36 impl<'a, 'tcx> ItemLikeVisitor<'tcx> for Collector<'a, 'tcx> {
  37     fn visit_item(&mut self, it: &'tcx hir::Item) {
  38         let fm = match it.node {
  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("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.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("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, m.span, E0458,
  78                                       "unknown kind: `{}`", k)
  79                                 .span_label(item.span, "unknown kind").emit();
  80                             cstore::NativeUnknown
  81                         }
  82                     };
  83                 } else if item.check_name("name") {
  84                     lib.name = item.value_str();
  85                 } else if item.check_name("cfg") {
  86                     let cfg = match item.meta_item_list() {
  87                         Some(list) => list,
  88                         None => continue, // skip like historical compilers
  89                     };
  90                     if cfg.is_empty() {
  91                         self.tcx.sess.span_err(
  92                             item.span(),
  93                             "`cfg()` must have an argument",
  94                         );
  95                     } else if let cfg @ Some(..) = cfg[0].meta_item() {
  96                         lib.cfg = cfg.cloned();
  97                     } else {
  98                         self.tcx.sess.span_err(cfg[0].span(), "invalid argument for `cfg(..)`");
  99                     }
 100                 } else if item.check_name("wasm_import_module") {
 101                     match item.value_str() {
 102                         Some(s) => lib.wasm_import_module = Some(s),
 103                         None => {
 104                             let msg = "must be of the form #[link(wasm_import_module = \"...\")]";
 105                             self.tcx.sess.span_err(item.span(), msg);
 106                         }
 107                     }
 108                 } else {
 109                     // currently, like past compilers, ignore unknown
 110                     // directives here.
 111                 }
 112             }
 113
 114             // In general we require #[link(name = "...")] but we allow
 115             // #[link(wasm_import_module = "...")] without the `name`.
 116             let requires_name = kind_specified || lib.wasm_import_module.is_none();
 117             if lib.name.is_none() && requires_name {
 118                 struct_span_err!(self.tcx.sess, m.span, E0459,
 119                                  "#[link(...)] specified without \
 120                                   `name = \"foo\"`")
 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) {}
 129     fn visit_impl_item(&mut self, _it: &'tcx hir::ImplItem) {}
 130 }
 131
 132 impl<'a, 'tcx> Collector<'a, 'tcx> {
 133     fn register_native_lib(&mut self, span: Option<Span>, lib: NativeLibrary) {
 134         if lib.name.as_ref().map(|s| s.as_str().is_empty()).unwrap_or(false) {
 135             match span {
 136                 Some(span) => {
 137                     struct_span_err!(self.tcx.sess, span, E0454,
 138                                      "#[link(name = \"\")] given with empty name")
 139                         .span_label(span, "empty name given")
 140                         .emit();
 141                 }
 142                 None => {
 143                     self.tcx.sess.err("empty library name given via `-l`");
 144                 }
 145             }
 146             return
 147         }
 148         let is_osx = self.tcx.sess.target.target.options.is_like_osx;
 149         if lib.kind == cstore::NativeFramework && !is_osx {
 150             let msg = "native frameworks are only available on macOS targets";
 151             match span {
 152                 Some(span) => span_err!(self.tcx.sess, span, E0455, "{}", msg),
 153                 None => self.tcx.sess.err(msg),
 154             }
 155         }
 156         if lib.cfg.is_some() && !self.tcx.features().link_cfg {
 157             feature_gate::emit_feature_err(&self.tcx.sess.parse_sess,
 158                                            "link_cfg",
 159                                            span.unwrap(),
 160                                            GateIssue::Language,
 161                                            "is feature gated");
 162         }
 163         if lib.kind == cstore::NativeStaticNobundle &&
 164            !self.tcx.features().static_nobundle {
 165             feature_gate::emit_feature_err(&self.tcx.sess.parse_sess,
 166                                            "static_nobundle",
 167                                            span.unwrap_or_else(|| syntax_pos::DUMMY_SP),
 168                                            GateIssue::Language,
 169                                            "kind=\"static-nobundle\" is feature gated");
 170         }
 171         self.libs.push(lib);
 172     }
 173
 174     // Process libs passed on the command line
 175     fn process_command_line(&mut self) {
 176         // First, check for errors
 177         let mut renames = FxHashSet::default();
 178         for &(ref name, ref new_name, _) in &self.tcx.sess.opts.libs {
 179             if let &Some(ref new_name) = new_name {
 180                 let any_duplicate = self.libs
 181                     .iter()
 182                     .filter_map(|lib| lib.name.as_ref())
 183                     .any(|n| n == name);
 184                 if new_name.is_empty() {
 185                     self.tcx.sess.err(
 186                         &format!("an empty renaming target was specified for library `{}`",name));
 187                 } else if !any_duplicate {
 188                     self.tcx.sess.err(&format!("renaming of the library `{}` was specified, \
 189                                                 however this crate contains no #[link(...)] \
 190                                                 attributes referencing this library.", name));
 191                 } else if renames.contains(name) {
 192                     self.tcx.sess.err(&format!("multiple renamings were \
 193                                                 specified for library `{}` .",
 194                                                name));
 195                 } else {
 196                     renames.insert(name);
 197                 }
 198             }
 199         }
 200
 201         // Update kind and, optionally, the name of all native libraries
 202         // (there may be more than one) with the specified name.
 203         for &(ref name, ref new_name, kind) in &self.tcx.sess.opts.libs {
 204             let mut found = false;
 205             for lib in self.libs.iter_mut() {
 206                 let lib_name = match lib.name {
 207                     Some(n) => n,
 208                     None => continue,
 209                 };
 210                 if lib_name == name as &str {
 211                     let mut changed = false;
 212                     if let Some(k) = kind {
 213                         lib.kind = k;
 214                         changed = true;
 215                     }
 216                     if let &Some(ref new_name) = new_name {
 217                         lib.name = Some(Symbol::intern(new_name));
 218                         changed = true;
 219                     }
 220                     if !changed {
 221                         let msg = format!("redundant linker flag specified for \
 222                                            library `{}`", name);
 223                         self.tcx.sess.warn(&msg);
 224                     }
 225
 226                     found = true;
 227                 }
 228             }
 229             if !found {
 230                 // Add if not found
 231                 let new_name = new_name.as_ref().map(|s| &**s); // &Option<String> -> Option<&str>
 232                 let lib = NativeLibrary {
 233                     name: Some(Symbol::intern(new_name.unwrap_or(name))),
 234                     kind: if let Some(k) = kind { k } else { cstore::NativeUnknown },
 235                     cfg: None,
 236                     foreign_module: None,
 237                     wasm_import_module: None,
 238                 };
 239                 self.register_native_lib(None, lib);
 240             }
 241         }
 242     }
 243 }