src/librustc_metadata/cstore.rs

   1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 #![allow(non_camel_case_types)]
  12
  13 // The crate store - a central repo for information collected about external
  14 // crates and libraries
  15
  16 pub use self::MetadataBlob::*;
  17
  18 use creader;
  19 use decoder;
  20 use index;
  21 use loader;
  22
  23 use rustc::back::svh::Svh;
  24 use rustc::front::map as ast_map;
  25 use rustc::util::nodemap::{FnvHashMap, NodeMap, NodeSet};
  26
  27 use std::cell::{RefCell, Ref, Cell};
  28 use std::rc::Rc;
  29 use std::path::PathBuf;
  30 use flate::Bytes;
  31 use syntax::ast;
  32 use syntax::attr;
  33 use syntax::codemap;
  34 use syntax::parse::token;
  35 use syntax::parse::token::IdentInterner;
  36 use syntax::util::small_vector::SmallVector;
  37
  38 pub use middle::cstore::{NativeLibraryKind, LinkagePreference};
  39 pub use middle::cstore::{NativeStatic, NativeFramework, NativeUnknown};
  40 pub use middle::cstore::{CrateSource, LinkMeta};
  41
  42 // A map from external crate numbers (as decoded from some crate file) to
  43 // local crate numbers (as generated during this session). Each external
  44 // crate may refer to types in other external crates, and each has their
  45 // own crate numbers.
  46 pub type cnum_map = FnvHashMap<ast::CrateNum, ast::CrateNum>;
  47
  48 pub enum MetadataBlob {
  49     MetadataVec(Bytes),
  50     MetadataArchive(loader::ArchiveMetadata),
  51 }
  52
  53 /// Holds information about a codemap::FileMap imported from another crate.
  54 /// See creader::import_codemap() for more information.
  55 pub struct ImportedFileMap {
  56     /// This FileMap's byte-offset within the codemap of its original crate
  57     pub original_start_pos: codemap::BytePos,
  58     /// The end of this FileMap within the codemap of its original crate
  59     pub original_end_pos: codemap::BytePos,
  60     /// The imported FileMap's representation within the local codemap
  61     pub translated_filemap: Rc<codemap::FileMap>
  62 }
  63
  64 pub struct crate_metadata {
  65     pub name: String,
  66     pub local_path: RefCell<SmallVector<ast_map::PathElem>>,
  67     pub local_def_path: RefCell<ast_map::DefPath>,
  68     pub data: MetadataBlob,
  69     pub cnum_map: RefCell<cnum_map>,
  70     pub cnum: ast::CrateNum,
  71     pub codemap_import_info: RefCell<Vec<ImportedFileMap>>,
  72     pub span: codemap::Span,
  73     pub staged_api: bool,
  74
  75     pub index: index::Index,
  76     pub xref_index: index::DenseIndex,
  77
  78     /// Flag if this crate is required by an rlib version of this crate, or in
  79     /// other words whether it was explicitly linked to. An example of a crate
  80     /// where this is false is when an allocator crate is injected into the
  81     /// dependency list, and therefore isn't actually needed to link an rlib.
  82     pub explicitly_linked: Cell<bool>,
  83 }
  84
  85 pub struct CStore {
  86     metas: RefCell<FnvHashMap<ast::CrateNum, Rc<crate_metadata>>>,
  87     /// Map from NodeId's of local extern crate statements to crate numbers
  88     extern_mod_crate_map: RefCell<NodeMap<ast::CrateNum>>,
  89     used_crate_sources: RefCell<Vec<CrateSource>>,
  90     used_libraries: RefCell<Vec<(String, NativeLibraryKind)>>,
  91     used_link_args: RefCell<Vec<String>>,
  92     statically_included_foreign_items: RefCell<NodeSet>,
  93     pub intr: Rc<IdentInterner>,
  94 }
  95
  96 impl CStore {
  97     pub fn new(intr: Rc<IdentInterner>) -> CStore {
  98         CStore {
  99             metas: RefCell::new(FnvHashMap()),
 100             extern_mod_crate_map: RefCell::new(FnvHashMap()),
 101             used_crate_sources: RefCell::new(Vec::new()),
 102             used_libraries: RefCell::new(Vec::new()),
 103             used_link_args: RefCell::new(Vec::new()),
 104             intr: intr,
 105             statically_included_foreign_items: RefCell::new(NodeSet()),
 106         }
 107     }
 108
 109     pub fn next_crate_num(&self) -> ast::CrateNum {
 110         self.metas.borrow().len() as ast::CrateNum + 1
 111     }
 112
 113     pub fn get_crate_data(&self, cnum: ast::CrateNum) -> Rc<crate_metadata> {
 114         self.metas.borrow().get(&cnum).unwrap().clone()
 115     }
 116
 117     pub fn get_crate_hash(&self, cnum: ast::CrateNum) -> Svh {
 118         let cdata = self.get_crate_data(cnum);
 119         decoder::get_crate_hash(cdata.data())
 120     }
 121
 122     pub fn set_crate_data(&self, cnum: ast::CrateNum, data: Rc<crate_metadata>) {
 123         self.metas.borrow_mut().insert(cnum, data);
 124     }
 125
 126     pub fn iter_crate_data<I>(&self, mut i: I) where
 127         I: FnMut(ast::CrateNum, &Rc<crate_metadata>),
 128     {
 129         for (&k, v) in self.metas.borrow().iter() {
 130             i(k, v);
 131         }
 132     }
 133
 134     /// Like `iter_crate_data`, but passes source paths (if available) as well.
 135     pub fn iter_crate_data_origins<I>(&self, mut i: I) where
 136         I: FnMut(ast::CrateNum, &crate_metadata, Option<CrateSource>),
 137     {
 138         for (&k, v) in self.metas.borrow().iter() {
 139             let origin = self.opt_used_crate_source(k);
 140             origin.as_ref().map(|cs| { assert!(k == cs.cnum); });
 141             i(k, &**v, origin);
 142         }
 143     }
 144
 145     pub fn add_used_crate_source(&self, src: CrateSource) {
 146         let mut used_crate_sources = self.used_crate_sources.borrow_mut();
 147         if !used_crate_sources.contains(&src) {
 148             used_crate_sources.push(src);
 149         }
 150     }
 151
 152     pub fn opt_used_crate_source(&self, cnum: ast::CrateNum)
 153                                  -> Option<CrateSource> {
 154         self.used_crate_sources.borrow_mut()
 155             .iter().find(|source| source.cnum == cnum).cloned()
 156     }
 157
 158     pub fn reset(&self) {
 159         self.metas.borrow_mut().clear();
 160         self.extern_mod_crate_map.borrow_mut().clear();
 161         self.used_crate_sources.borrow_mut().clear();
 162         self.used_libraries.borrow_mut().clear();
 163         self.used_link_args.borrow_mut().clear();
 164         self.statically_included_foreign_items.borrow_mut().clear();
 165     }
 166
 167     // This method is used when generating the command line to pass through to
 168     // system linker. The linker expects undefined symbols on the left of the
 169     // command line to be defined in libraries on the right, not the other way
 170     // around. For more info, see some comments in the add_used_library function
 171     // below.
 172     //
 173     // In order to get this left-to-right dependency ordering, we perform a
 174     // topological sort of all crates putting the leaves at the right-most
 175     // positions.
 176     pub fn do_get_used_crates(&self, prefer: LinkagePreference)
 177                               -> Vec<(ast::CrateNum, Option<PathBuf>)> {
 178         let mut ordering = Vec::new();
 179         fn visit(cstore: &CStore, cnum: ast::CrateNum,
 180                  ordering: &mut Vec<ast::CrateNum>) {
 181             if ordering.contains(&cnum) { return }
 182             let meta = cstore.get_crate_data(cnum);
 183             for (_, &dep) in meta.cnum_map.borrow().iter() {
 184                 visit(cstore, dep, ordering);
 185             }
 186             ordering.push(cnum);
 187         }
 188         for (&num, _) in self.metas.borrow().iter() {
 189             visit(self, num, &mut ordering);
 190         }
 191         info!("topological ordering: {:?}", ordering);
 192         ordering.reverse();
 193         let mut libs = self.used_crate_sources.borrow()
 194             .iter()
 195             .map(|src| (src.cnum, match prefer {
 196                 LinkagePreference::RequireDynamic => src.dylib.clone().map(|p| p.0),
 197                 LinkagePreference::RequireStatic => src.rlib.clone().map(|p| p.0),
 198             }))
 199             .collect::<Vec<_>>();
 200         libs.sort_by(|&(a, _), &(b, _)| {
 201             let a = ordering.iter().position(|x| *x == a);
 202             let b = ordering.iter().position(|x| *x == b);
 203             a.cmp(&b)
 204         });
 205         libs
 206     }
 207
 208     pub fn add_used_library(&self, lib: String, kind: NativeLibraryKind) {
 209         assert!(!lib.is_empty());
 210         self.used_libraries.borrow_mut().push((lib, kind));
 211     }
 212
 213     pub fn get_used_libraries<'a>(&'a self)
 214                               -> &'a RefCell<Vec<(String,
 215                                                   NativeLibraryKind)>> {
 216         &self.used_libraries
 217     }
 218
 219     pub fn add_used_link_args(&self, args: &str) {
 220         for s in args.split(' ').filter(|s| !s.is_empty()) {
 221             self.used_link_args.borrow_mut().push(s.to_string());
 222         }
 223     }
 224
 225     pub fn get_used_link_args<'a>(&'a self) -> &'a RefCell<Vec<String> > {
 226         &self.used_link_args
 227     }
 228
 229     pub fn add_extern_mod_stmt_cnum(&self,
 230                                     emod_id: ast::NodeId,
 231                                     cnum: ast::CrateNum) {
 232         self.extern_mod_crate_map.borrow_mut().insert(emod_id, cnum);
 233     }
 234
 235     pub fn add_statically_included_foreign_item(&self, id: ast::NodeId) {
 236         self.statically_included_foreign_items.borrow_mut().insert(id);
 237     }
 238
 239     pub fn do_is_statically_included_foreign_item(&self, id: ast::NodeId) -> bool {
 240         self.statically_included_foreign_items.borrow().contains(&id)
 241     }
 242
 243     pub fn do_extern_mod_stmt_cnum(&self, emod_id: ast::NodeId) -> Option<ast::CrateNum>
 244     {
 245         self.extern_mod_crate_map.borrow().get(&emod_id).cloned()
 246     }
 247 }
 248
 249 impl crate_metadata {
 250     pub fn data<'a>(&'a self) -> &'a [u8] { self.data.as_slice() }
 251     pub fn name(&self) -> String { decoder::get_crate_name(self.data()) }
 252     pub fn hash(&self) -> Svh { decoder::get_crate_hash(self.data()) }
 253     pub fn imported_filemaps<'a>(&'a self, codemap: &codemap::CodeMap)
 254                                  -> Ref<'a, Vec<ImportedFileMap>> {
 255         let filemaps = self.codemap_import_info.borrow();
 256         if filemaps.is_empty() {
 257             drop(filemaps);
 258             let filemaps = creader::import_codemap(codemap, &self.data);
 259
 260             // This shouldn't borrow twice, but there is no way to downgrade RefMut to Ref.
 261             *self.codemap_import_info.borrow_mut() = filemaps;
 262             self.codemap_import_info.borrow()
 263         } else {
 264             filemaps
 265         }
 266     }
 267
 268     pub fn with_local_path<T, F>(&self, f: F) -> T
 269         where F: Fn(&[ast_map::PathElem]) -> T
 270     {
 271         let cpath = self.local_path.borrow();
 272         if cpath.is_empty() {
 273             let name = ast_map::PathMod(token::intern(&self.name));
 274             f(&[name])
 275         } else {
 276             f(cpath.as_slice())
 277         }
 278     }
 279
 280     pub fn update_local_path<'a, 'b>(&self, candidate: ast_map::PathElems<'a, 'b>) {
 281         let mut cpath = self.local_path.borrow_mut();
 282         let cap = cpath.len();
 283         match cap {
 284             0 => *cpath = candidate.collect(),
 285             1 => (),
 286             _ => {
 287                 let candidate: SmallVector<_> = candidate.collect();
 288                 if candidate.len() < cap {
 289                     *cpath = candidate;
 290                 }
 291             },
 292         }
 293     }
 294
 295     pub fn local_def_path(&self) -> ast_map::DefPath {
 296         let local_def_path = self.local_def_path.borrow();
 297         if local_def_path.is_empty() {
 298             let name = ast_map::DefPathData::DetachedCrate(token::intern(&self.name));
 299             vec![ast_map::DisambiguatedDefPathData { data: name, disambiguator: 0 }]
 300         } else {
 301             local_def_path.clone()
 302         }
 303     }
 304
 305     pub fn update_local_def_path(&self, candidate: ast_map::DefPath) {
 306         let mut local_def_path = self.local_def_path.borrow_mut();
 307         if local_def_path.is_empty() || candidate.len() < local_def_path.len() {
 308             *local_def_path = candidate;
 309         }
 310     }
 311
 312     pub fn is_allocator(&self) -> bool {
 313         let attrs = decoder::get_crate_attributes(self.data());
 314         attr::contains_name(&attrs, "allocator")
 315     }
 316
 317     pub fn needs_allocator(&self) -> bool {
 318         let attrs = decoder::get_crate_attributes(self.data());
 319         attr::contains_name(&attrs, "needs_allocator")
 320     }
 321 }
 322
 323 impl MetadataBlob {
 324     pub fn as_slice<'a>(&'a self) -> &'a [u8] {
 325         let slice = match *self {
 326             MetadataVec(ref vec) => &vec[..],
 327             MetadataArchive(ref ar) => ar.as_slice(),
 328         };
 329         if slice.len() < 4 {
 330             &[] // corrupt metadata
 331         } else {
 332             let len = (((slice[0] as u32) << 24) |
 333                        ((slice[1] as u32) << 16) |
 334                        ((slice[2] as u32) << 8) |
 335                        ((slice[3] as u32) << 0)) as usize;
 336             if len + 4 <= slice.len() {
 337                 &slice[4.. len + 4]
 338             } else {
 339                 &[] // corrupt or old metadata
 340             }
 341         }
 342     }
 343 }