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