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// Decoding metadata from a single crate's metadata
use crate::cstore::{self, CrateMetadata, MetadataBlob, NativeLibrary, ForeignModule};
use crate::schema::*;
use rustc_data_structures::sync::{Lrc, ReadGuard};
use rustc::hir::map::{DefKey, DefPath, DefPathData, DefPathHash, Definitions};
use rustc::hir;
use rustc::middle::cstore::LinkagePreference;
use rustc::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
use rustc::hir::def::{self, Res, DefKind, CtorOf, CtorKind};
use rustc::hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
use rustc::hir::map::definitions::DefPathTable;
use rustc_data_structures::fingerprint::Fingerprint;
use rustc::middle::lang_items;
use rustc::mir::{self, interpret};
use rustc::mir::interpret::AllocDecodingSession;
use rustc::session::Session;
use rustc::ty::{self, Ty, TyCtxt};
use rustc::ty::codec::TyDecoder;
use rustc::mir::Body;
use rustc::util::captures::Captures;
use std::io;
use std::mem;
use std::u32;
use rustc_serialize::{Decodable, Decoder, SpecializedDecoder, opaque};
use syntax::attr;
use syntax::ast::{self, Ident};
use syntax::source_map;
use syntax::symbol::{Symbol, sym};
use syntax::ext::base::{MacroKind, SyntaxExtension};
use syntax::ext::hygiene::Mark;
use syntax_pos::{self, Span, BytePos, Pos, DUMMY_SP, NO_EXPANSION};
use log::debug;
pub struct DecodeContext<'a, 'tcx> {
opaque: opaque::Decoder<'a>,
cdata: Option<&'a CrateMetadata>,
sess: Option<&'tcx Session>,
tcx: Option<TyCtxt<'tcx>>,
// Cache the last used source_file for translating spans as an optimization.
last_source_file_index: usize,
lazy_state: LazyState,
// Used for decoding interpret::AllocIds in a cached & thread-safe manner.
alloc_decoding_session: Option<AllocDecodingSession<'a>>,
}
/// Abstract over the various ways one can create metadata decoders.
pub trait Metadata<'a, 'tcx>: Copy {
fn raw_bytes(self) -> &'a [u8];
fn cdata(self) -> Option<&'a CrateMetadata> { None }
fn sess(self) -> Option<&'tcx Session> { None }
fn tcx(self) -> Option<TyCtxt<'tcx>> { None }
fn decoder(self, pos: usize) -> DecodeContext<'a, 'tcx> {
let tcx = self.tcx();
DecodeContext {
opaque: opaque::Decoder::new(self.raw_bytes(), pos),
cdata: self.cdata(),
sess: self.sess().or(tcx.map(|tcx| tcx.sess)),
tcx,
last_source_file_index: 0,
lazy_state: LazyState::NoNode,
alloc_decoding_session: self.cdata().map(|cdata| {
cdata.alloc_decoding_state.new_decoding_session()
}),
}
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for &'a MetadataBlob {
fn raw_bytes(self) -> &'a [u8] {
&self.0
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a MetadataBlob, &'tcx Session) {
fn raw_bytes(self) -> &'a [u8] {
let (blob, _) = self;
&blob.0
}
fn sess(self) -> Option<&'tcx Session> {
let (_, sess) = self;
Some(sess)
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for &'a CrateMetadata {
fn raw_bytes(self) -> &'a [u8] {
self.blob.raw_bytes()
}
fn cdata(self) -> Option<&'a CrateMetadata> {
Some(self)
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a CrateMetadata, &'tcx Session) {
fn raw_bytes(self) -> &'a [u8] {
self.0.raw_bytes()
}
fn cdata(self) -> Option<&'a CrateMetadata> {
Some(self.0)
}
fn sess(self) -> Option<&'tcx Session> {
Some(&self.1)
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a CrateMetadata, TyCtxt<'tcx>) {
fn raw_bytes(self) -> &'a [u8] {
self.0.raw_bytes()
}
fn cdata(self) -> Option<&'a CrateMetadata> {
Some(self.0)
}
fn tcx(self) -> Option<TyCtxt<'tcx>> {
Some(self.1)
}
}
impl<'a, 'tcx, T: Decodable> Lazy<T> {
pub fn decode<M: Metadata<'a, 'tcx>>(self, meta: M) -> T {
let mut dcx = meta.decoder(self.position);
dcx.lazy_state = LazyState::NodeStart(self.position);
T::decode(&mut dcx).unwrap()
}
}
impl<'a: 'x, 'tcx: 'x, 'x, T: Decodable> LazySeq<T> {
pub fn decode<M: Metadata<'a, 'tcx>>(
self,
meta: M,
) -> impl Iterator<Item = T> + Captures<'a> + Captures<'tcx> + 'x {
let mut dcx = meta.decoder(self.position);
dcx.lazy_state = LazyState::NodeStart(self.position);
(0..self.len).map(move |_| T::decode(&mut dcx).unwrap())
}
}
impl<'a, 'tcx> DecodeContext<'a, 'tcx> {
pub fn tcx(&self) -> TyCtxt<'tcx> {
self.tcx.expect("missing TyCtxt in DecodeContext")
}
pub fn cdata(&self) -> &'a CrateMetadata {
self.cdata.expect("missing CrateMetadata in DecodeContext")
}
fn read_lazy_distance(&mut self, min_size: usize) -> Result<usize, <Self as Decoder>::Error> {
let distance = self.read_usize()?;
let position = match self.lazy_state {
LazyState::NoNode => bug!("read_lazy_distance: outside of a metadata node"),
LazyState::NodeStart(start) => {
assert!(distance + min_size <= start);
start - distance - min_size
}
LazyState::Previous(last_min_end) => last_min_end + distance,
};
self.lazy_state = LazyState::Previous(position + min_size);
Ok(position)
}
}
impl<'a, 'tcx> TyDecoder<'tcx> for DecodeContext<'a, 'tcx> {
#[inline]
fn tcx(&self) -> TyCtxt<'tcx> {
self.tcx.expect("missing TyCtxt in DecodeContext")
}
#[inline]
fn peek_byte(&self) -> u8 {
self.opaque.data[self.opaque.position()]
}
#[inline]
fn position(&self) -> usize {
self.opaque.position()
}
fn cached_ty_for_shorthand<F>(&mut self,
shorthand: usize,
or_insert_with: F)
-> Result<Ty<'tcx>, Self::Error>
where F: FnOnce(&mut Self) -> Result<Ty<'tcx>, Self::Error>
{
let tcx = self.tcx();
let key = ty::CReaderCacheKey {
cnum: self.cdata().cnum,
pos: shorthand,
};
if let Some(&ty) = tcx.rcache.borrow().get(&key) {
return Ok(ty);
}
let ty = or_insert_with(self)?;
tcx.rcache.borrow_mut().insert(key, ty);
Ok(ty)
}
fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
where F: FnOnce(&mut Self) -> R
{
let new_opaque = opaque::Decoder::new(self.opaque.data, pos);
let old_opaque = mem::replace(&mut self.opaque, new_opaque);
let old_state = mem::replace(&mut self.lazy_state, LazyState::NoNode);
let r = f(self);
self.opaque = old_opaque;
self.lazy_state = old_state;
r
}
fn map_encoded_cnum_to_current(&self, cnum: CrateNum) -> CrateNum {
if cnum == LOCAL_CRATE {
self.cdata().cnum
} else {
self.cdata().cnum_map[cnum]
}
}
}
impl<'a, 'tcx, T> SpecializedDecoder<Lazy<T>> for DecodeContext<'a, 'tcx> {
fn specialized_decode(&mut self) -> Result<Lazy<T>, Self::Error> {
Ok(Lazy::with_position(self.read_lazy_distance(Lazy::<T>::min_size())?))
}
}
impl<'a, 'tcx, T> SpecializedDecoder<LazySeq<T>> for DecodeContext<'a, 'tcx> {
fn specialized_decode(&mut self) -> Result<LazySeq<T>, Self::Error> {
let len = self.read_usize()?;
let position = if len == 0 {
0
} else {
self.read_lazy_distance(LazySeq::<T>::min_size(len))?
};
Ok(LazySeq::with_position_and_length(position, len))
}
}
impl<'a, 'tcx> SpecializedDecoder<DefId> for DecodeContext<'a, 'tcx> {
#[inline]
fn specialized_decode(&mut self) -> Result<DefId, Self::Error> {
let krate = CrateNum::decode(self)?;
let index = DefIndex::decode(self)?;
Ok(DefId {
krate,
index,
})
}
}
impl<'a, 'tcx> SpecializedDecoder<DefIndex> for DecodeContext<'a, 'tcx> {
#[inline]
fn specialized_decode(&mut self) -> Result<DefIndex, Self::Error> {
Ok(DefIndex::from_u32(self.read_u32()?))
}
}
impl<'a, 'tcx> SpecializedDecoder<LocalDefId> for DecodeContext<'a, 'tcx> {
#[inline]
fn specialized_decode(&mut self) -> Result<LocalDefId, Self::Error> {
self.specialized_decode().map(|i| LocalDefId::from_def_id(i))
}
}
impl<'a, 'tcx> SpecializedDecoder<interpret::AllocId> for DecodeContext<'a, 'tcx> {
fn specialized_decode(&mut self) -> Result<interpret::AllocId, Self::Error> {
if let Some(alloc_decoding_session) = self.alloc_decoding_session {
alloc_decoding_session.decode_alloc_id(self)
} else {
bug!("Attempting to decode interpret::AllocId without CrateMetadata")
}
}
}
impl<'a, 'tcx> SpecializedDecoder<Span> for DecodeContext<'a, 'tcx> {
fn specialized_decode(&mut self) -> Result<Span, Self::Error> {
let tag = u8::decode(self)?;
if tag == TAG_INVALID_SPAN {
return Ok(DUMMY_SP)
}
debug_assert_eq!(tag, TAG_VALID_SPAN);
let lo = BytePos::decode(self)?;
let len = BytePos::decode(self)?;
let hi = lo + len;
let sess = if let Some(sess) = self.sess {
sess
} else {
bug!("Cannot decode Span without Session.")
};
let imported_source_files = self.cdata().imported_source_files(&sess.source_map());
let source_file = {
// Optimize for the case that most spans within a translated item
// originate from the same source_file.
let last_source_file = &imported_source_files[self.last_source_file_index];
if lo >= last_source_file.original_start_pos &&
lo <= last_source_file.original_end_pos {
last_source_file
} else {
let mut a = 0;
let mut b = imported_source_files.len();
while b - a > 1 {
let m = (a + b) / 2;
if imported_source_files[m].original_start_pos > lo {
b = m;
} else {
a = m;
}
}
self.last_source_file_index = a;
&imported_source_files[a]
}
};
// Make sure our binary search above is correct.
debug_assert!(lo >= source_file.original_start_pos &&
lo <= source_file.original_end_pos);
// Make sure we correctly filtered out invalid spans during encoding
debug_assert!(hi >= source_file.original_start_pos &&
hi <= source_file.original_end_pos);
let lo = (lo + source_file.translated_source_file.start_pos)
- source_file.original_start_pos;
let hi = (hi + source_file.translated_source_file.start_pos)
- source_file.original_start_pos;
Ok(Span::new(lo, hi, NO_EXPANSION))
}
}
impl<'a, 'tcx> SpecializedDecoder<Fingerprint> for DecodeContext<'a, 'tcx> {
fn specialized_decode(&mut self) -> Result<Fingerprint, Self::Error> {
Fingerprint::decode_opaque(&mut self.opaque)
}
}
impl<'a, 'tcx, T: Decodable> SpecializedDecoder<mir::ClearCrossCrate<T>>
for DecodeContext<'a, 'tcx> {
#[inline]
fn specialized_decode(&mut self) -> Result<mir::ClearCrossCrate<T>, Self::Error> {
Ok(mir::ClearCrossCrate::Clear)
}
}
implement_ty_decoder!( DecodeContext<'a, 'tcx> );
impl<'tcx> MetadataBlob {
pub fn is_compatible(&self) -> bool {
self.raw_bytes().starts_with(METADATA_HEADER)
}
pub fn get_rustc_version(&self) -> String {
Lazy::with_position(METADATA_HEADER.len() + 4).decode(self)
}
pub fn get_root(&self) -> CrateRoot<'tcx> {
let slice = self.raw_bytes();
let offset = METADATA_HEADER.len();
let pos = (((slice[offset + 0] as u32) << 24) | ((slice[offset + 1] as u32) << 16) |
((slice[offset + 2] as u32) << 8) |
((slice[offset + 3] as u32) << 0)) as usize;
Lazy::with_position(pos).decode(self)
}
pub fn list_crate_metadata(&self,
out: &mut dyn io::Write) -> io::Result<()> {
write!(out, "=External Dependencies=\n")?;
let root = self.get_root();
for (i, dep) in root.crate_deps
.decode(self)
.enumerate() {
write!(out, "{} {}{}\n", i + 1, dep.name, dep.extra_filename)?;
}
write!(out, "\n")?;
Ok(())
}
}
impl<'tcx> EntryKind<'tcx> {
fn def_kind(&self) -> Option<DefKind> {
Some(match *self {
EntryKind::Const(..) => DefKind::Const,
EntryKind::AssocConst(..) => DefKind::AssocConst,
EntryKind::ImmStatic |
EntryKind::MutStatic |
EntryKind::ForeignImmStatic |
EntryKind::ForeignMutStatic => DefKind::Static,
EntryKind::Struct(_, _) => DefKind::Struct,
EntryKind::Union(_, _) => DefKind::Union,
EntryKind::Fn(_) |
EntryKind::ForeignFn(_) => DefKind::Fn,
EntryKind::Method(_) => DefKind::Method,
EntryKind::Type => DefKind::TyAlias,
EntryKind::TypeParam => DefKind::TyParam,
EntryKind::ConstParam => DefKind::ConstParam,
EntryKind::Existential => DefKind::Existential,
EntryKind::AssocType(_) => DefKind::AssocTy,
EntryKind::AssocExistential(_) => DefKind::AssocExistential,
EntryKind::Mod(_) => DefKind::Mod,
EntryKind::Variant(_) => DefKind::Variant,
EntryKind::Trait(_) => DefKind::Trait,
EntryKind::TraitAlias(_) => DefKind::TraitAlias,
EntryKind::Enum(..) => DefKind::Enum,
EntryKind::MacroDef(_) => DefKind::Macro(MacroKind::Bang),
EntryKind::ForeignType => DefKind::ForeignTy,
EntryKind::ForeignMod |
EntryKind::GlobalAsm |
EntryKind::Impl(_) |
EntryKind::Field |
EntryKind::Generator(_) |
EntryKind::Closure(_) => return None,
})
}
}
/// Creates the "fake" DefPathTable for a given proc macro crate.
///
/// The DefPathTable is as follows:
///
/// CRATE_ROOT (DefIndex 0:0)
/// |- GlobalMetaDataKind data (DefIndex 1:0 .. DefIndex 1:N)
/// |- proc macro #0 (DefIndex 1:N)
/// |- proc macro #1 (DefIndex 1:N+1)
/// \- ...
crate fn proc_macro_def_path_table(crate_root: &CrateRoot<'_>,
proc_macros: &[(ast::Name, Lrc<SyntaxExtension>)])
-> DefPathTable
{
let mut definitions = Definitions::default();
let name = crate_root.name.as_str();
let disambiguator = crate_root.disambiguator;
debug!("creating proc macro def path table for {:?}/{:?}", name, disambiguator);
let crate_root = definitions.create_root_def(&name, disambiguator);
for (index, (name, _)) in proc_macros.iter().enumerate() {
let def_index = definitions.create_def_with_parent(
crate_root,
ast::DUMMY_NODE_ID,
DefPathData::MacroNs(name.as_interned_str()),
Mark::root(),
DUMMY_SP);
debug!("definition for {:?} is {:?}", name, def_index);
assert_eq!(def_index, DefIndex::from_proc_macro_index(index));
}
definitions.def_path_table().clone()
}
impl<'a, 'tcx> CrateMetadata {
fn is_proc_macro(&self, id: DefIndex) -> bool {
self.proc_macros.is_some() && id != CRATE_DEF_INDEX
}
fn maybe_entry(&self, item_id: DefIndex) -> Option<Lazy<Entry<'tcx>>> {
assert!(!self.is_proc_macro(item_id));
self.root.entries_index.lookup(self.blob.raw_bytes(), item_id)
}
fn entry(&self, item_id: DefIndex) -> Entry<'tcx> {
match self.maybe_entry(item_id) {
None => {
bug!("entry: id not found: {:?} in crate {:?} with number {}",
item_id,
self.name,
self.cnum)
}
Some(d) => d.decode(self),
}
}
fn local_def_id(&self, index: DefIndex) -> DefId {
DefId {
krate: self.cnum,
index,
}
}
pub fn item_name(&self, item_index: DefIndex) -> Symbol {
self.def_key(item_index)
.disambiguated_data
.data
.get_opt_name()
.expect("no name in item_name")
.as_symbol()
}
pub fn def_kind(&self, index: DefIndex) -> Option<DefKind> {
if !self.is_proc_macro(index) {
self.entry(index).kind.def_kind()
} else {
Some(DefKind::Macro(
self.proc_macros.as_ref().unwrap()[index.to_proc_macro_index()].1.macro_kind()
))
}
}
pub fn get_span(&self, index: DefIndex, sess: &Session) -> Span {
match self.is_proc_macro(index) {
true => DUMMY_SP,
false => self.entry(index).span.decode((self, sess)),
}
}
pub fn get_trait_def(&self, item_id: DefIndex, sess: &Session) -> ty::TraitDef {
match self.entry(item_id).kind {
EntryKind::Trait(data) => {
let data = data.decode((self, sess));
ty::TraitDef::new(self.local_def_id(item_id),
data.unsafety,
data.paren_sugar,
data.has_auto_impl,
data.is_marker,
self.def_path_table.def_path_hash(item_id))
},
EntryKind::TraitAlias(_) => {
ty::TraitDef::new(self.local_def_id(item_id),
hir::Unsafety::Normal,
false,
false,
false,
self.def_path_table.def_path_hash(item_id))
},
_ => bug!("def-index does not refer to trait or trait alias"),
}
}
fn get_variant(
&self,
tcx: TyCtxt<'tcx>,
item: &Entry<'_>,
index: DefIndex,
parent_did: DefId,
adt_kind: ty::AdtKind,
) -> ty::VariantDef {
let data = match item.kind {
EntryKind::Variant(data) |
EntryKind::Struct(data, _) |
EntryKind::Union(data, _) => data.decode(self),
_ => bug!(),
};
let variant_did = if adt_kind == ty::AdtKind::Enum {
Some(self.local_def_id(index))
} else {
None
};
let ctor_did = data.ctor.map(|index| self.local_def_id(index));
ty::VariantDef::new(
tcx,
Ident::with_empty_ctxt(self.item_name(index)),
variant_did,
ctor_did,
data.discr,
item.children.decode(self).map(|index| {
let f = self.entry(index);
ty::FieldDef {
did: self.local_def_id(index),
ident: Ident::with_empty_ctxt(self.item_name(index)),
vis: f.visibility.decode(self)
}
}).collect(),
data.ctor_kind,
adt_kind,
parent_did,
false,
)
}
pub fn get_adt_def(&self, item_id: DefIndex, tcx: TyCtxt<'tcx>) -> &'tcx ty::AdtDef {
let item = self.entry(item_id);
let did = self.local_def_id(item_id);
let (kind, repr) = match item.kind {
EntryKind::Enum(repr) => (ty::AdtKind::Enum, repr),
EntryKind::Struct(_, repr) => (ty::AdtKind::Struct, repr),
EntryKind::Union(_, repr) => (ty::AdtKind::Union, repr),
_ => bug!("get_adt_def called on a non-ADT {:?}", did),
};
let variants = if let ty::AdtKind::Enum = kind {
item.children
.decode(self)
.map(|index| {
self.get_variant(tcx, &self.entry(index), index, did, kind)
})
.collect()
} else {
std::iter::once(self.get_variant(tcx, &item, item_id, did, kind)).collect()
};
tcx.alloc_adt_def(did, kind, variants, repr)
}
pub fn get_predicates(
&self,
item_id: DefIndex,
tcx: TyCtxt<'tcx>,
) -> ty::GenericPredicates<'tcx> {
self.entry(item_id).predicates.unwrap().decode((self, tcx))
}
pub fn get_predicates_defined_on(
&self,
item_id: DefIndex,
tcx: TyCtxt<'tcx>,
) -> ty::GenericPredicates<'tcx> {
self.entry(item_id).predicates_defined_on.unwrap().decode((self, tcx))
}
pub fn get_super_predicates(
&self,
item_id: DefIndex,
tcx: TyCtxt<'tcx>,
) -> ty::GenericPredicates<'tcx> {
let super_predicates = match self.entry(item_id).kind {
EntryKind::Trait(data) => data.decode(self).super_predicates,
EntryKind::TraitAlias(data) => data.decode(self).super_predicates,
_ => bug!("def-index does not refer to trait or trait alias"),
};
super_predicates.decode((self, tcx))
}
pub fn get_generics(&self,
item_id: DefIndex,
sess: &Session)
-> ty::Generics {
self.entry(item_id).generics.unwrap().decode((self, sess))
}
pub fn get_type(&self, id: DefIndex, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
self.entry(id).ty.unwrap().decode((self, tcx))
}
pub fn get_stability(&self, id: DefIndex) -> Option<attr::Stability> {
match self.is_proc_macro(id) {
true => self.root.proc_macro_stability.clone(),
false => self.entry(id).stability.map(|stab| stab.decode(self)),
}
}
pub fn get_deprecation(&self, id: DefIndex) -> Option<attr::Deprecation> {
match self.is_proc_macro(id) {
true => None,
false => self.entry(id).deprecation.map(|depr| depr.decode(self)),
}
}
pub fn get_visibility(&self, id: DefIndex) -> ty::Visibility {
match self.is_proc_macro(id) {
true => ty::Visibility::Public,
false => self.entry(id).visibility.decode(self),
}
}
fn get_impl_data(&self, id: DefIndex) -> ImplData<'tcx> {
match self.entry(id).kind {
EntryKind::Impl(data) => data.decode(self),
_ => bug!(),
}
}
pub fn get_parent_impl(&self, id: DefIndex) -> Option<DefId> {
self.get_impl_data(id).parent_impl
}
pub fn get_impl_polarity(&self, id: DefIndex) -> hir::ImplPolarity {
self.get_impl_data(id).polarity
}
pub fn get_impl_defaultness(&self, id: DefIndex) -> hir::Defaultness {
self.get_impl_data(id).defaultness
}
pub fn get_coerce_unsized_info(&self,
id: DefIndex)
-> Option<ty::adjustment::CoerceUnsizedInfo> {
self.get_impl_data(id).coerce_unsized_info
}
pub fn get_impl_trait(&self, id: DefIndex, tcx: TyCtxt<'tcx>) -> Option<ty::TraitRef<'tcx>> {
self.get_impl_data(id).trait_ref.map(|tr| tr.decode((self, tcx)))
}
/// Iterates over all the stability attributes in the given crate.
pub fn get_lib_features(&self, tcx: TyCtxt<'tcx>) -> &'tcx [(ast::Name, Option<ast::Name>)] {
// FIXME: For a proc macro crate, not sure whether we should return the "host"
// features or an empty Vec. Both don't cause ICEs.
tcx.arena.alloc_from_iter(self.root
.lib_features
.decode(self))
}
/// Iterates over the language items in the given crate.
pub fn get_lang_items(&self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, usize)] {
if self.proc_macros.is_some() {
// Proc macro crates do not export any lang-items to the target.
&[]
} else {
tcx.arena.alloc_from_iter(self.root
.lang_items
.decode(self)
.map(|(def_index, index)| (self.local_def_id(def_index), index)))
}
}
/// Iterates over each child of the given item.
pub fn each_child_of_item<F>(&self, id: DefIndex, mut callback: F, sess: &Session)
where F: FnMut(def::Export<hir::HirId>)
{
if let Some(ref proc_macros) = self.proc_macros {
/* If we are loading as a proc macro, we want to return the view of this crate
* as a proc macro crate, not as a Rust crate. See `proc_macro_def_path_table`
* for the DefPathTable we are corresponding to.
*/
if id == CRATE_DEF_INDEX {
for (id, &(name, ref ext)) in proc_macros.iter().enumerate() {
let res = Res::Def(
DefKind::Macro(ext.macro_kind()),
self.local_def_id(DefIndex::from_proc_macro_index(id)),
);
let ident = Ident::with_empty_ctxt(name);
callback(def::Export {
ident: ident,
res: res,
vis: ty::Visibility::Public,
span: DUMMY_SP,
});
}
}
return
}
// Find the item.
let item = match self.maybe_entry(id) {
None => return,
Some(item) => item.decode((self, sess)),
};
// Iterate over all children.
let macros_only = self.dep_kind.lock().macros_only();
for child_index in item.children.decode((self, sess)) {
if macros_only {
continue
}
// Get the item.
if let Some(child) = self.maybe_entry(child_index) {
let child = child.decode((self, sess));
match child.kind {
EntryKind::MacroDef(..) => {}
_ if macros_only => continue,
_ => {}
}
// Hand off the item to the callback.
match child.kind {
// FIXME(eddyb) Don't encode these in children.
EntryKind::ForeignMod => {
for child_index in child.children.decode((self, sess)) {
if let Some(kind) = self.def_kind(child_index) {
callback(def::Export {
res: Res::Def(kind, self.local_def_id(child_index)),
ident: Ident::with_empty_ctxt(self.item_name(child_index)),
vis: self.get_visibility(child_index),
span: self.entry(child_index).span.decode((self, sess)),
});
}
}
continue;
}
EntryKind::Impl(_) => continue,
_ => {}
}
let def_key = self.def_key(child_index);
let span = child.span.decode((self, sess));
if let (Some(kind), Some(name)) =
(self.def_kind(child_index), def_key.disambiguated_data.data.get_opt_name()) {
let ident = Ident::from_interned_str(name);
let vis = self.get_visibility(child_index);
let def_id = self.local_def_id(child_index);
let res = Res::Def(kind, def_id);
callback(def::Export { res, ident, vis, span });
// For non-re-export structs and variants add their constructors to children.
// Re-export lists automatically contain constructors when necessary.
match kind {
DefKind::Struct => {
if let Some(ctor_def_id) = self.get_ctor_def_id(child_index) {
let ctor_kind = self.get_ctor_kind(child_index);
let ctor_res = Res::Def(
DefKind::Ctor(CtorOf::Struct, ctor_kind),
ctor_def_id,
);
let vis = self.get_visibility(ctor_def_id.index);
callback(def::Export { res: ctor_res, vis, ident, span });
}
}
DefKind::Variant => {
// Braced variants, unlike structs, generate unusable names in
// value namespace, they are reserved for possible future use.
// It's ok to use the variant's id as a ctor id since an
// error will be reported on any use of such resolution anyway.
let ctor_def_id = self.get_ctor_def_id(child_index).unwrap_or(def_id);
let ctor_kind = self.get_ctor_kind(child_index);
let ctor_res = Res::Def(
DefKind::Ctor(CtorOf::Variant, ctor_kind),
ctor_def_id,
);
let mut vis = self.get_visibility(ctor_def_id.index);
if ctor_def_id == def_id && vis == ty::Visibility::Public {
// For non-exhaustive variants lower the constructor visibility to
// within the crate. We only need this for fictive constructors,
// for other constructors correct visibilities
// were already encoded in metadata.
let attrs = self.get_item_attrs(def_id.index, sess);
if attr::contains_name(&attrs, sym::non_exhaustive) {
let crate_def_id = self.local_def_id(CRATE_DEF_INDEX);
vis = ty::Visibility::Restricted(crate_def_id);
}
}
callback(def::Export { res: ctor_res, ident, vis, span });
}
_ => {}
}
}
}
}
if let EntryKind::Mod(data) = item.kind {
for exp in data.decode((self, sess)).reexports.decode((self, sess)) {
match exp.res {
Res::Def(DefKind::Macro(..), _) => {}
_ if macros_only => continue,
_ => {}
}
callback(exp);
}
}
}
pub fn const_is_rvalue_promotable_to_static(&self, id: DefIndex) -> bool {
match self.entry(id).kind {
EntryKind::AssocConst(_, data, _) |
EntryKind::Const(data, _) => data.ast_promotable,
_ => bug!(),
}
}
pub fn is_item_mir_available(&self, id: DefIndex) -> bool {
!self.is_proc_macro(id) &&
self.maybe_entry(id).and_then(|item| item.decode(self).mir).is_some()
}
pub fn maybe_get_optimized_mir(&self, tcx: TyCtxt<'tcx>, id: DefIndex) -> Option<Body<'tcx>> {
match self.is_proc_macro(id) {
true => None,
false => self.entry(id).mir.map(|mir| mir.decode((self, tcx))),
}
}
pub fn mir_const_qualif(&self, id: DefIndex) -> u8 {
match self.entry(id).kind {
EntryKind::Const(qualif, _) |
EntryKind::AssocConst(AssocContainer::ImplDefault, qualif, _) |
EntryKind::AssocConst(AssocContainer::ImplFinal, qualif, _) => {
qualif.mir
}
_ => bug!(),
}
}
pub fn get_associated_item(&self, id: DefIndex) -> ty::AssocItem {
let item = self.entry(id);
let def_key = self.def_key(id);
let parent = self.local_def_id(def_key.parent.unwrap());
let name = def_key.disambiguated_data.data.get_opt_name().unwrap();
let (kind, container, has_self) = match item.kind {
EntryKind::AssocConst(container, _, _) => {
(ty::AssocKind::Const, container, false)
}
EntryKind::Method(data) => {
let data = data.decode(self);
(ty::AssocKind::Method, data.container, data.has_self)
}
EntryKind::AssocType(container) => {
(ty::AssocKind::Type, container, false)
}
EntryKind::AssocExistential(container) => {
(ty::AssocKind::Existential, container, false)
}
_ => bug!("cannot get associated-item of `{:?}`", def_key)
};
ty::AssocItem {
ident: Ident::from_interned_str(name),
kind,
vis: item.visibility.decode(self),
defaultness: container.defaultness(),
def_id: self.local_def_id(id),
container: container.with_def_id(parent),
method_has_self_argument: has_self
}
}
pub fn get_item_variances(&self, id: DefIndex) -> Vec<ty::Variance> {
self.entry(id).variances.decode(self).collect()
}
pub fn get_ctor_kind(&self, node_id: DefIndex) -> CtorKind {
match self.entry(node_id).kind {
EntryKind::Struct(data, _) |
EntryKind::Union(data, _) |
EntryKind::Variant(data) => data.decode(self).ctor_kind,
_ => CtorKind::Fictive,
}
}
pub fn get_ctor_def_id(&self, node_id: DefIndex) -> Option<DefId> {
match self.entry(node_id).kind {
EntryKind::Struct(data, _) => {
data.decode(self).ctor.map(|index| self.local_def_id(index))
}
EntryKind::Variant(data) => {
data.decode(self).ctor.map(|index| self.local_def_id(index))
}
_ => None,
}
}
pub fn get_item_attrs(&self, node_id: DefIndex, sess: &Session) -> Lrc<[ast::Attribute]> {
if self.is_proc_macro(node_id) {
return Lrc::new([]);
}
// The attributes for a tuple struct/variant are attached to the definition, not the ctor;
// we assume that someone passing in a tuple struct ctor is actually wanting to
// look at the definition
let def_key = self.def_key(node_id);
let item_id = if def_key.disambiguated_data.data == DefPathData::Ctor {
def_key.parent.unwrap()
} else {
node_id
};
let item = self.entry(item_id);
Lrc::from(self.get_attributes(&item, sess))
}
pub fn get_struct_field_names(&self, id: DefIndex) -> Vec<ast::Name> {
self.entry(id)
.children
.decode(self)
.map(|index| self.item_name(index))
.collect()
}
fn get_attributes(&self, item: &Entry<'tcx>, sess: &Session) -> Vec<ast::Attribute> {
item.attributes
.decode((self, sess))
.map(|mut attr| {
// Need new unique IDs: old thread-local IDs won't map to new threads.
attr.id = attr::mk_attr_id();
attr
})
.collect()
}
// Translate a DefId from the current compilation environment to a DefId
// for an external crate.
fn reverse_translate_def_id(&self, did: DefId) -> Option<DefId> {
for (local, &global) in self.cnum_map.iter_enumerated() {
if global == did.krate {
return Some(DefId {
krate: local,
index: did.index,
});
}
}
None
}
pub fn get_inherent_implementations_for_type(
&self,
tcx: TyCtxt<'tcx>,
id: DefIndex,
) -> &'tcx [DefId] {
tcx.arena.alloc_from_iter(self.entry(id)
.inherent_impls
.decode(self)
.map(|index| self.local_def_id(index)))
}
pub fn get_implementations_for_trait(
&self,
tcx: TyCtxt<'tcx>,
filter: Option<DefId>,
) -> &'tcx [DefId] {
if self.proc_macros.is_some() {
// proc-macro crates export no trait impls.
return &[]
}
// Do a reverse lookup beforehand to avoid touching the crate_num
// hash map in the loop below.
let filter = match filter.map(|def_id| self.reverse_translate_def_id(def_id)) {
Some(Some(def_id)) => Some((def_id.krate.as_u32(), def_id.index)),
Some(None) => return &[],
None => None,
};
if let Some(filter) = filter {
if let Some(impls) = self.trait_impls.get(&filter) {
tcx.arena.alloc_from_iter(impls.decode(self).map(|idx| self.local_def_id(idx)))
} else {
&[]
}
} else {
tcx.arena.alloc_from_iter(self.trait_impls.values().flat_map(|impls| {
impls.decode(self).map(|idx| self.local_def_id(idx))
}))
}
}
pub fn get_trait_of_item(&self, id: DefIndex) -> Option<DefId> {
let def_key = self.def_key(id);
match def_key.disambiguated_data.data {
DefPathData::TypeNs(..) | DefPathData::ValueNs(..) => (),
// Not an associated item
_ => return None,
}
def_key.parent.and_then(|parent_index| {
match self.entry(parent_index).kind {
EntryKind::Trait(_) |
EntryKind::TraitAlias(_) => Some(self.local_def_id(parent_index)),
_ => None,
}
})
}
pub fn get_native_libraries(&self, sess: &Session) -> Vec<NativeLibrary> {
if self.proc_macros.is_some() {
// Proc macro crates do not have any *target* native libraries.
vec![]
} else {
self.root.native_libraries.decode((self, sess)).collect()
}
}
pub fn get_foreign_modules(&self, tcx: TyCtxt<'tcx>) -> &'tcx [ForeignModule] {
if self.proc_macros.is_some() {
// Proc macro crates do not have any *target* foreign modules.
&[]
} else {
tcx.arena.alloc_from_iter(self.root.foreign_modules.decode((self, tcx.sess)))
}
}
pub fn get_dylib_dependency_formats(
&self,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(CrateNum, LinkagePreference)] {
tcx.arena.alloc_from_iter(self.root
.dylib_dependency_formats
.decode(self)
.enumerate()
.flat_map(|(i, link)| {
let cnum = CrateNum::new(i + 1);
link.map(|link| (self.cnum_map[cnum], link))
}))
}
pub fn get_missing_lang_items(&self, tcx: TyCtxt<'tcx>) -> &'tcx [lang_items::LangItem] {
if self.proc_macros.is_some() {
// Proc macro crates do not depend on any target weak lang-items.
&[]
} else {
tcx.arena.alloc_from_iter(self.root
.lang_items_missing
.decode(self))
}
}
pub fn get_fn_arg_names(&self, id: DefIndex) -> Vec<ast::Name> {
let arg_names = match self.entry(id).kind {
EntryKind::Fn(data) |
EntryKind::ForeignFn(data) => data.decode(self).arg_names,
EntryKind::Method(data) => data.decode(self).fn_data.arg_names,
_ => LazySeq::empty(),
};
arg_names.decode(self).collect()
}
pub fn exported_symbols(
&self,
tcx: TyCtxt<'tcx>,
) -> Vec<(ExportedSymbol<'tcx>, SymbolExportLevel)> {
if self.proc_macros.is_some() {
// If this crate is a custom derive crate, then we're not even going to
// link those in so we skip those crates.
vec![]
} else {
self.root.exported_symbols.decode((self, tcx)).collect()
}
}
pub fn get_rendered_const(&self, id: DefIndex) -> String {
match self.entry(id).kind {
EntryKind::Const(_, data) |
EntryKind::AssocConst(_, _, data) => data.decode(self).0,
_ => bug!(),
}
}
pub fn get_macro(&self, id: DefIndex) -> MacroDef {
let entry = self.entry(id);
match entry.kind {
EntryKind::MacroDef(macro_def) => macro_def.decode(self),
_ => bug!(),
}
}
crate fn is_const_fn_raw(&self, id: DefIndex) -> bool {
let constness = match self.entry(id).kind {
EntryKind::Method(data) => data.decode(self).fn_data.constness,
EntryKind::Fn(data) => data.decode(self).constness,
EntryKind::Variant(..) | EntryKind::Struct(..) => hir::Constness::Const,
_ => hir::Constness::NotConst,
};
constness == hir::Constness::Const
}
pub fn is_foreign_item(&self, id: DefIndex) -> bool {
match self.entry(id).kind {
EntryKind::ForeignImmStatic |
EntryKind::ForeignMutStatic |
EntryKind::ForeignFn(_) => true,
_ => false,
}
}
crate fn static_mutability(&self, id: DefIndex) -> Option<hir::Mutability> {
match self.entry(id).kind {
EntryKind::ImmStatic |
EntryKind::ForeignImmStatic => Some(hir::MutImmutable),
EntryKind::MutStatic |
EntryKind::ForeignMutStatic => Some(hir::MutMutable),
_ => None,
}
}
pub fn fn_sig(&self, id: DefIndex, tcx: TyCtxt<'tcx>) -> ty::PolyFnSig<'tcx> {
let sig = match self.entry(id).kind {
EntryKind::Fn(data) |
EntryKind::ForeignFn(data) => data.decode(self).sig,
EntryKind::Method(data) => data.decode(self).fn_data.sig,
EntryKind::Variant(data) |
EntryKind::Struct(data, _) => data.decode(self).ctor_sig.unwrap(),
EntryKind::Closure(data) => data.decode(self).sig,
_ => bug!(),
};
sig.decode((self, tcx))
}
#[inline]
pub fn def_key(&self, index: DefIndex) -> DefKey {
self.def_path_table.def_key(index)
}
// Returns the path leading to the thing with this `id`.
pub fn def_path(&self, id: DefIndex) -> DefPath {
debug!("def_path(cnum={:?}, id={:?})", self.cnum, id);
DefPath::make(self.cnum, id, |parent| self.def_path_table.def_key(parent))
}
#[inline]
pub fn def_path_hash(&self, index: DefIndex) -> DefPathHash {
self.def_path_table.def_path_hash(index)
}
/// Imports the source_map from an external crate into the source_map of the crate
/// currently being compiled (the "local crate").
///
/// The import algorithm works analogous to how AST items are inlined from an
/// external crate's metadata:
/// For every SourceFile in the external source_map an 'inline' copy is created in the
/// local source_map. The correspondence relation between external and local
/// SourceFiles is recorded in the `ImportedSourceFile` objects returned from this
/// function. When an item from an external crate is later inlined into this
/// crate, this correspondence information is used to translate the span
/// information of the inlined item so that it refers the correct positions in
/// the local source_map (see `<decoder::DecodeContext as SpecializedDecoder<Span>>`).
///
/// The import algorithm in the function below will reuse SourceFiles already
/// existing in the local source_map. For example, even if the SourceFile of some
/// source file of libstd gets imported many times, there will only ever be
/// one SourceFile object for the corresponding file in the local source_map.
///
/// Note that imported SourceFiles do not actually contain the source code of the
/// file they represent, just information about length, line breaks, and
/// multibyte characters. This information is enough to generate valid debuginfo
/// for items inlined from other crates.
///
/// Proc macro crates don't currently export spans, so this function does not have
/// to work for them.
pub fn imported_source_files(&'a self,
local_source_map: &source_map::SourceMap)
-> ReadGuard<'a, Vec<cstore::ImportedSourceFile>> {
{
let source_files = self.source_map_import_info.borrow();
if !source_files.is_empty() {
return source_files;
}
}
// Lock the source_map_import_info to ensure this only happens once
let mut source_map_import_info = self.source_map_import_info.borrow_mut();
if !source_map_import_info.is_empty() {
drop(source_map_import_info);
return self.source_map_import_info.borrow();
}
let external_source_map = self.root.source_map.decode(self);
let imported_source_files = external_source_map.map(|source_file_to_import| {
// We can't reuse an existing SourceFile, so allocate a new one
// containing the information we need.
let syntax_pos::SourceFile { name,
name_was_remapped,
src_hash,
start_pos,
end_pos,
mut lines,
mut multibyte_chars,
mut non_narrow_chars,
name_hash,
.. } = source_file_to_import;
let source_length = (end_pos - start_pos).to_usize();
// Translate line-start positions and multibyte character
// position into frame of reference local to file.
// `SourceMap::new_imported_source_file()` will then translate those
// coordinates to their new global frame of reference when the
// offset of the SourceFile is known.
for pos in &mut lines {
*pos = *pos - start_pos;
}
for mbc in &mut multibyte_chars {
mbc.pos = mbc.pos - start_pos;
}
for swc in &mut non_narrow_chars {
*swc = *swc - start_pos;
}
let local_version = local_source_map.new_imported_source_file(name,
name_was_remapped,
self.cnum.as_u32(),
src_hash,
name_hash,
source_length,
lines,
multibyte_chars,
non_narrow_chars);
debug!("CrateMetaData::imported_source_files alloc \
source_file {:?} original (start_pos {:?} end_pos {:?}) \
translated (start_pos {:?} end_pos {:?})",
local_version.name, start_pos, end_pos,
local_version.start_pos, local_version.end_pos);
cstore::ImportedSourceFile {
original_start_pos: start_pos,
original_end_pos: end_pos,
translated_source_file: local_version,
}
}).collect();
*source_map_import_info = imported_source_files;
drop(source_map_import_info);
// This shouldn't borrow twice, but there is no way to downgrade RefMut to Ref.
self.source_map_import_info.borrow()
}
}
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