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 // The crate store - a central repo for information collected about external
  12 // crates and libraries
  13
  14 use schema;
  15 use rustc::hir::def_id::{CrateNum, DefIndex};
  16 use rustc::hir::map::definitions::DefPathTable;
  17 use rustc::middle::cstore::{DepKind, ExternCrate, MetadataLoader};
  18 use rustc::mir::interpret::AllocDecodingState;
  19 use rustc_data_structures::indexed_vec::IndexVec;
  20 use rustc::util::nodemap::{FxHashMap, NodeMap};
  21
  22 use rustc_data_structures::sync::{Lrc, RwLock, Lock};
  23 use syntax::ast;
  24 use syntax::ext::base::SyntaxExtension;
  25 use syntax::symbol::Symbol;
  26 use syntax_pos;
  27
  28 pub use rustc::middle::cstore::{NativeLibrary, NativeLibraryKind, LinkagePreference};
  29 pub use rustc::middle::cstore::NativeLibraryKind::*;
  30 pub use rustc::middle::cstore::{CrateSource, LibSource, ForeignModule};
  31
  32 pub use cstore_impl::{provide, provide_extern};
  33
  34 // A map from external crate numbers (as decoded from some crate file) to
  35 // local crate numbers (as generated during this session). Each external
  36 // crate may refer to types in other external crates, and each has their
  37 // own crate numbers.
  38 pub type CrateNumMap = IndexVec<CrateNum, CrateNum>;
  39
  40 pub use rustc_data_structures::sync::MetadataRef;
  41
  42 pub struct MetadataBlob(pub MetadataRef);
  43
  44 /// Holds information about a syntax_pos::FileMap imported from another crate.
  45 /// See `imported_filemaps()` for more information.
  46 pub struct ImportedFileMap {
  47     /// This FileMap's byte-offset within the codemap of its original crate
  48     pub original_start_pos: syntax_pos::BytePos,
  49     /// The end of this FileMap within the codemap of its original crate
  50     pub original_end_pos: syntax_pos::BytePos,
  51     /// The imported FileMap's representation within the local codemap
  52     pub translated_filemap: Lrc<syntax_pos::FileMap>,
  53 }
  54
  55 pub struct CrateMetadata {
  56     pub name: Symbol,
  57
  58     /// Information about the extern crate that caused this crate to
  59     /// be loaded. If this is `None`, then the crate was injected
  60     /// (e.g., by the allocator)
  61     pub extern_crate: Lock<Option<ExternCrate>>,
  62
  63     pub blob: MetadataBlob,
  64     pub cnum_map: CrateNumMap,
  65     pub cnum: CrateNum,
  66     pub dependencies: Lock<Vec<CrateNum>>,
  67     pub codemap_import_info: RwLock<Vec<ImportedFileMap>>,
  68
  69     /// Used for decoding interpret::AllocIds in a cached & thread-safe manner.
  70     pub alloc_decoding_state: AllocDecodingState,
  71
  72     pub root: schema::CrateRoot,
  73
  74     /// For each public item in this crate, we encode a key.  When the
  75     /// crate is loaded, we read all the keys and put them in this
  76     /// hashmap, which gives the reverse mapping.  This allows us to
  77     /// quickly retrace a `DefPath`, which is needed for incremental
  78     /// compilation support.
  79     pub def_path_table: Lrc<DefPathTable>,
  80
  81     pub trait_impls: FxHashMap<(u32, DefIndex), schema::LazySeq<DefIndex>>,
  82
  83     pub dep_kind: Lock<DepKind>,
  84     pub source: CrateSource,
  85
  86     pub proc_macros: Option<Vec<(ast::Name, Lrc<SyntaxExtension>)>>,
  87 }
  88
  89 pub struct CStore {
  90     metas: RwLock<IndexVec<CrateNum, Option<Lrc<CrateMetadata>>>>,
  91     /// Map from NodeId's of local extern crate statements to crate numbers
  92     extern_mod_crate_map: Lock<NodeMap<CrateNum>>,
  93     pub metadata_loader: Box<MetadataLoader + Sync>,
  94 }
  95
  96 impl CStore {
  97     pub fn new(metadata_loader: Box<MetadataLoader + Sync>) -> CStore {
  98         CStore {
  99             // We add an empty entry for LOCAL_CRATE (which maps to zero) in
 100             // order to make array indices in `metas` match with the
 101             // corresponding `CrateNum`. This first entry will always remain
 102             // `None`.
 103             metas: RwLock::new(IndexVec::from_elem_n(None, 1)),
 104             extern_mod_crate_map: Lock::new(FxHashMap()),
 105             metadata_loader,
 106         }
 107     }
 108
 109     pub(super) fn alloc_new_crate_num(&self) -> CrateNum {
 110         let mut metas = self.metas.borrow_mut();
 111         let cnum = CrateNum::new(metas.len());
 112         metas.push(None);
 113         cnum
 114     }
 115
 116     pub(super) fn get_crate_data(&self, cnum: CrateNum) -> Lrc<CrateMetadata> {
 117         self.metas.borrow()[cnum].clone().unwrap()
 118     }
 119
 120     pub(super) fn set_crate_data(&self, cnum: CrateNum, data: Lrc<CrateMetadata>) {
 121         let mut metas = self.metas.borrow_mut();
 122         assert!(metas[cnum].is_none(), "Overwriting crate metadata entry");
 123         metas[cnum] = Some(data);
 124     }
 125
 126     pub(super) fn iter_crate_data<I>(&self, mut i: I)
 127         where I: FnMut(CrateNum, &Lrc<CrateMetadata>)
 128     {
 129         for (k, v) in self.metas.borrow().iter_enumerated() {
 130             if let &Some(ref v) = v {
 131                 i(k, v);
 132             }
 133         }
 134     }
 135
 136     pub(super) fn crate_dependencies_in_rpo(&self, krate: CrateNum) -> Vec<CrateNum> {
 137         let mut ordering = Vec::new();
 138         self.push_dependencies_in_postorder(&mut ordering, krate);
 139         ordering.reverse();
 140         ordering
 141     }
 142
 143     pub(super) fn push_dependencies_in_postorder(&self,
 144                                                  ordering: &mut Vec<CrateNum>,
 145                                                  krate: CrateNum) {
 146         if ordering.contains(&krate) {
 147             return;
 148         }
 149
 150         let data = self.get_crate_data(krate);
 151         for &dep in data.dependencies.borrow().iter() {
 152             if dep != krate {
 153                 self.push_dependencies_in_postorder(ordering, dep);
 154             }
 155         }
 156
 157         ordering.push(krate);
 158     }
 159
 160     pub(super) fn do_postorder_cnums_untracked(&self) -> Vec<CrateNum> {
 161         let mut ordering = Vec::new();
 162         for (num, v) in self.metas.borrow().iter_enumerated() {
 163             if let &Some(_) = v {
 164                 self.push_dependencies_in_postorder(&mut ordering, num);
 165             }
 166         }
 167         return ordering
 168     }
 169
 170     pub(super) fn add_extern_mod_stmt_cnum(&self, emod_id: ast::NodeId, cnum: CrateNum) {
 171         self.extern_mod_crate_map.borrow_mut().insert(emod_id, cnum);
 172     }
 173
 174     pub(super) fn do_extern_mod_stmt_cnum(&self, emod_id: ast::NodeId) -> Option<CrateNum> {
 175         self.extern_mod_crate_map.borrow().get(&emod_id).cloned()
 176     }
 177 }