compiler/rustc_session/src/cstore.rs

   1 //! the rustc crate store interface. This also includes types that
   2 //! are *mostly* used as a part of that interface, but these should
   3 //! probably get a better home if someone can find one.
   4
   5 use crate::search_paths::PathKind;
   6 use crate::utils::NativeLibKind;
   7 use crate::Session;
   8 use rustc_ast as ast;
   9 use rustc_data_structures::sync::{self, MetadataRef};
  10 use rustc_hir::def_id::{CrateNum, DefId, StableCrateId, LOCAL_CRATE};
  11 use rustc_hir::definitions::{DefKey, DefPath, DefPathHash};
  12 use rustc_span::hygiene::{ExpnHash, ExpnId};
  13 use rustc_span::symbol::Symbol;
  14 use rustc_span::Span;
  15 use rustc_target::spec::Target;
  16
  17 use std::any::Any;
  18 use std::path::{Path, PathBuf};
  19
  20 // lonely orphan structs and enums looking for a better home
  21
  22 /// Where a crate came from on the local filesystem. One of these three options
  23 /// must be non-None.
  24 #[derive(PartialEq, Clone, Debug, HashStable_Generic, Encodable, Decodable)]
  25 pub struct CrateSource {
  26     pub dylib: Option<(PathBuf, PathKind)>,
  27     pub rlib: Option<(PathBuf, PathKind)>,
  28     pub rmeta: Option<(PathBuf, PathKind)>,
  29 }
  30
  31 impl CrateSource {
  32     #[inline]
  33     pub fn paths(&self) -> impl Iterator<Item = &PathBuf> {
  34         self.dylib.iter().chain(self.rlib.iter()).chain(self.rmeta.iter()).map(|p| &p.0)
  35     }
  36 }
  37
  38 #[derive(Encodable, Decodable, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Debug)]
  39 #[derive(HashStable_Generic)]
  40 pub enum CrateDepKind {
  41     /// A dependency that is only used for its macros.
  42     MacrosOnly,
  43     /// A dependency that is always injected into the dependency list and so
  44     /// doesn't need to be linked to an rlib, e.g., the injected allocator.
  45     Implicit,
  46     /// A dependency that is required by an rlib version of this crate.
  47     /// Ordinary `extern crate`s result in `Explicit` dependencies.
  48     Explicit,
  49 }
  50
  51 impl CrateDepKind {
  52     #[inline]
  53     pub fn macros_only(self) -> bool {
  54         match self {
  55             CrateDepKind::MacrosOnly => true,
  56             CrateDepKind::Implicit | CrateDepKind::Explicit => false,
  57         }
  58     }
  59 }
  60
  61 #[derive(Copy, Debug, PartialEq, Clone, Encodable, Decodable, HashStable_Generic)]
  62 pub enum LinkagePreference {
  63     RequireDynamic,
  64     RequireStatic,
  65 }
  66
  67 #[derive(Debug, Encodable, Decodable, HashStable_Generic)]
  68 pub struct NativeLib {
  69     pub kind: NativeLibKind,
  70     pub name: Option<Symbol>,
  71     pub cfg: Option<ast::MetaItem>,
  72     pub foreign_module: Option<DefId>,
  73     pub wasm_import_module: Option<Symbol>,
  74     pub verbatim: Option<bool>,
  75     pub dll_imports: Vec<DllImport>,
  76 }
  77
  78 #[derive(Clone, Debug, Encodable, Decodable, HashStable_Generic)]
  79 pub struct DllImport {
  80     pub name: Symbol,
  81     pub ordinal: Option<u16>,
  82     /// Calling convention for the function.
  83     ///
  84     /// On x86_64, this is always `DllCallingConvention::C`; on i686, it can be any
  85     /// of the values, and we use `DllCallingConvention::C` to represent `"cdecl"`.
  86     pub calling_convention: DllCallingConvention,
  87     /// Span of import's "extern" declaration; used for diagnostics.
  88     pub span: Span,
  89 }
  90
  91 /// Calling convention for a function defined in an external library.
  92 ///
  93 /// The usize value, where present, indicates the size of the function's argument list
  94 /// in bytes.
  95 #[derive(Clone, PartialEq, Debug, Encodable, Decodable, HashStable_Generic)]
  96 pub enum DllCallingConvention {
  97     C,
  98     Stdcall(usize),
  99     Fastcall(usize),
 100     Vectorcall(usize),
 101 }
 102
 103 #[derive(Clone, Encodable, Decodable, HashStable_Generic, Debug)]
 104 pub struct ForeignModule {
 105     pub foreign_items: Vec<DefId>,
 106     pub def_id: DefId,
 107 }
 108
 109 #[derive(Copy, Clone, Debug, HashStable_Generic)]
 110 pub struct ExternCrate {
 111     pub src: ExternCrateSource,
 112
 113     /// span of the extern crate that caused this to be loaded
 114     pub span: Span,
 115
 116     /// Number of links to reach the extern;
 117     /// used to select the extern with the shortest path
 118     pub path_len: usize,
 119
 120     /// Crate that depends on this crate
 121     pub dependency_of: CrateNum,
 122 }
 123
 124 impl ExternCrate {
 125     /// If true, then this crate is the crate named by the extern
 126     /// crate referenced above. If false, then this crate is a dep
 127     /// of the crate.
 128     #[inline]
 129     pub fn is_direct(&self) -> bool {
 130         self.dependency_of == LOCAL_CRATE
 131     }
 132
 133     #[inline]
 134     pub fn rank(&self) -> impl PartialOrd {
 135         // Prefer:
 136         // - direct extern crate to indirect
 137         // - shorter paths to longer
 138         (self.is_direct(), !self.path_len)
 139     }
 140 }
 141
 142 #[derive(Copy, Clone, Debug, HashStable_Generic)]
 143 pub enum ExternCrateSource {
 144     /// Crate is loaded by `extern crate`.
 145     Extern(
 146         /// def_id of the item in the current crate that caused
 147         /// this crate to be loaded; note that there could be multiple
 148         /// such ids
 149         DefId,
 150     ),
 151     /// Crate is implicitly loaded by a path resolving through extern prelude.
 152     Path,
 153 }
 154
 155 /// The backend's way to give the crate store access to the metadata in a library.
 156 /// Note that it returns the raw metadata bytes stored in the library file, whether
 157 /// it is compressed, uncompressed, some weird mix, etc.
 158 /// rmeta files are backend independent and not handled here.
 159 ///
 160 /// At the time of this writing, there is only one backend and one way to store
 161 /// metadata in library -- this trait just serves to decouple rustc_metadata from
 162 /// the archive reader, which depends on LLVM.
 163 pub trait MetadataLoader {
 164     fn get_rlib_metadata(&self, target: &Target, filename: &Path) -> Result<MetadataRef, String>;
 165     fn get_dylib_metadata(&self, target: &Target, filename: &Path) -> Result<MetadataRef, String>;
 166 }
 167
 168 pub type MetadataLoaderDyn = dyn MetadataLoader + Sync;
 169
 170 /// A store of Rust crates, through which their metadata can be accessed.
 171 ///
 172 /// Note that this trait should probably not be expanding today. All new
 173 /// functionality should be driven through queries instead!
 174 ///
 175 /// If you find a method on this trait named `{name}_untracked` it signifies
 176 /// that it's *not* tracked for dependency information throughout compilation
 177 /// (it'd break incremental compilation) and should only be called pre-HIR (e.g.
 178 /// during resolve)
 179 pub trait CrateStore: std::fmt::Debug {
 180     fn as_any(&self) -> &dyn Any;
 181
 182     // Foreign definitions.
 183     // This information is safe to access, since it's hashed as part of the DefPathHash, which incr.
 184     // comp. uses to identify a DefId.
 185     fn def_key(&self, def: DefId) -> DefKey;
 186     fn def_path(&self, def: DefId) -> DefPath;
 187     fn def_path_hash(&self, def: DefId) -> DefPathHash;
 188
 189     // This information is safe to access, since it's hashed as part of the StableCrateId, which
 190     // incr.  comp. uses to identify a CrateNum.
 191     fn crate_name(&self, cnum: CrateNum) -> Symbol;
 192     fn stable_crate_id(&self, cnum: CrateNum) -> StableCrateId;
 193     fn stable_crate_id_to_crate_num(&self, stable_crate_id: StableCrateId) -> CrateNum;
 194
 195     /// Fetch a DefId from a DefPathHash for a foreign crate.
 196     fn def_path_hash_to_def_id(&self, cnum: CrateNum, hash: DefPathHash) -> DefId;
 197     fn expn_hash_to_expn_id(
 198         &self,
 199         sess: &Session,
 200         cnum: CrateNum,
 201         index_guess: u32,
 202         hash: ExpnHash,
 203     ) -> ExpnId;
 204 }
 205
 206 pub type CrateStoreDyn = dyn CrateStore + sync::Sync;