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fuchsia / third_party / rust / 7bade6ef730cff83f3591479a98916920f66decd / . / compiler / rustc_metadata / src / rmeta / encoder.rs
blob: 7e33a479228bac820441c093e9a70b480a8906fc [file] [log] [blame]
use crate::rmeta::table::{FixedSizeEncoding, TableBuilder};
use crate::rmeta::*;
use rustc_ast as ast;
use rustc_data_structures::fingerprint::{Fingerprint, FingerprintEncoder};
use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
use rustc_data_structures::stable_hasher::StableHasher;
use rustc_data_structures::sync::{join, Lrc};
use rustc_hir as hir;
use rustc_hir::def::CtorKind;
use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
use rustc_hir::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor};
use rustc_hir::lang_items;
use rustc_hir::{AnonConst, GenericParamKind};
use rustc_index::bit_set::GrowableBitSet;
use rustc_index::vec::Idx;
use rustc_middle::hir::map::Map;
use rustc_middle::middle::cstore::{EncodedMetadata, ForeignModule, LinkagePreference, NativeLib};
use rustc_middle::middle::dependency_format::Linkage;
use rustc_middle::middle::exported_symbols::{
metadata_symbol_name, ExportedSymbol, SymbolExportLevel,
};
use rustc_middle::mir::interpret;
use rustc_middle::traits::specialization_graph;
use rustc_middle::ty::codec::TyEncoder;
use rustc_middle::ty::{self, SymbolName, Ty, TyCtxt};
use rustc_serialize::{opaque, Encodable, Encoder};
use rustc_session::config::CrateType;
use rustc_span::hygiene::{ExpnDataEncodeMode, HygieneEncodeContext};
use rustc_span::symbol::{sym, Ident, Symbol};
use rustc_span::{self, ExternalSource, FileName, SourceFile, Span, SyntaxContext};
use rustc_target::abi::VariantIdx;
use std::hash::Hash;
use std::num::NonZeroUsize;
use std::path::Path;
use tracing::{debug, trace};
pub(super) struct EncodeContext<'a, 'tcx> {
opaque: opaque::Encoder,
tcx: TyCtxt<'tcx>,
feat: &'tcx rustc_feature::Features,
tables: TableBuilders<'tcx>,
lazy_state: LazyState,
type_shorthands: FxHashMap<Ty<'tcx>, usize>,
predicate_shorthands: FxHashMap<ty::Predicate<'tcx>, usize>,
interpret_allocs: FxIndexSet<interpret::AllocId>,
// This is used to speed up Span encoding.
// The `usize` is an index into the `MonotonicVec`
// that stores the `SourceFile`
source_file_cache: (Lrc<SourceFile>, usize),
// The indices (into the `SourceMap`'s `MonotonicVec`)
// of all of the `SourceFiles` that we need to serialize.
// When we serialize a `Span`, we insert the index of its
// `SourceFile` into the `GrowableBitSet`.
//
// This needs to be a `GrowableBitSet` and not a
// regular `BitSet` because we may actually import new `SourceFiles`
// during metadata encoding, due to executing a query
// with a result containing a foreign `Span`.
required_source_files: Option<GrowableBitSet<usize>>,
is_proc_macro: bool,
hygiene_ctxt: &'a HygieneEncodeContext,
}
/// If the current crate is a proc-macro, returns early with `Lazy:empty()`.
/// This is useful for skipping the encoding of things that aren't needed
/// for proc-macro crates.
macro_rules! empty_proc_macro {
($self:ident) => {
if $self.is_proc_macro {
return Lazy::empty();
}
};
}
macro_rules! encoder_methods {
($($name:ident($ty:ty);)*) => {
$(fn $name(&mut self, value: $ty) -> Result<(), Self::Error> {
self.opaque.$name(value)
})*
}
}
impl<'a, 'tcx> Encoder for EncodeContext<'a, 'tcx> {
type Error = <opaque::Encoder as Encoder>::Error;
#[inline]
fn emit_unit(&mut self) -> Result<(), Self::Error> {
Ok(())
}
encoder_methods! {
emit_usize(usize);
emit_u128(u128);
emit_u64(u64);
emit_u32(u32);
emit_u16(u16);
emit_u8(u8);
emit_isize(isize);
emit_i128(i128);
emit_i64(i64);
emit_i32(i32);
emit_i16(i16);
emit_i8(i8);
emit_bool(bool);
emit_f64(f64);
emit_f32(f32);
emit_char(char);
emit_str(&str);
}
}
impl<'a, 'tcx, T: Encodable<EncodeContext<'a, 'tcx>>> Encodable<EncodeContext<'a, 'tcx>>
for Lazy<T>
{
fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
e.emit_lazy_distance(*self)
}
}
impl<'a, 'tcx, T: Encodable<EncodeContext<'a, 'tcx>>> Encodable<EncodeContext<'a, 'tcx>>
for Lazy<[T]>
{
fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
e.emit_usize(self.meta)?;
if self.meta == 0 {
return Ok(());
}
e.emit_lazy_distance(*self)
}
}
impl<'a, 'tcx, I: Idx, T: Encodable<EncodeContext<'a, 'tcx>>> Encodable<EncodeContext<'a, 'tcx>>
for Lazy<Table<I, T>>
where
Option<T>: FixedSizeEncoding,
{
fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
e.emit_usize(self.meta)?;
e.emit_lazy_distance(*self)
}
}
impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for CrateNum {
fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
if *self != LOCAL_CRATE && s.is_proc_macro {
panic!("Attempted to encode non-local CrateNum {:?} for proc-macro crate", self);
}
s.emit_u32(self.as_u32())
}
}
impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for DefIndex {
fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
s.emit_u32(self.as_u32())
}
}
impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for SyntaxContext {
fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
rustc_span::hygiene::raw_encode_syntax_context(*self, &s.hygiene_ctxt, s)
}
}
impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for ExpnId {
fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
rustc_span::hygiene::raw_encode_expn_id(
*self,
&s.hygiene_ctxt,
ExpnDataEncodeMode::Metadata,
s,
)
}
}
impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
if *self == rustc_span::DUMMY_SP {
return TAG_INVALID_SPAN.encode(s);
}
let span = self.data();
// The Span infrastructure should make sure that this invariant holds:
debug_assert!(span.lo <= span.hi);
if !s.source_file_cache.0.contains(span.lo) {
let source_map = s.tcx.sess.source_map();
let source_file_index = source_map.lookup_source_file_idx(span.lo);
s.source_file_cache =
(source_map.files()[source_file_index].clone(), source_file_index);
}
if !s.source_file_cache.0.contains(span.hi) {
// Unfortunately, macro expansion still sometimes generates Spans
// that malformed in this way.
return TAG_INVALID_SPAN.encode(s);
}
let source_files = s.required_source_files.as_mut().expect("Already encoded SourceMap!");
// Record the fact that we need to encode the data for this `SourceFile`
source_files.insert(s.source_file_cache.1);
// There are two possible cases here:
// 1. This span comes from a 'foreign' crate - e.g. some crate upstream of the
// crate we are writing metadata for. When the metadata for *this* crate gets
// deserialized, the deserializer will need to know which crate it originally came
// from. We use `TAG_VALID_SPAN_FOREIGN` to indicate that a `CrateNum` should
// be deserialized after the rest of the span data, which tells the deserializer
// which crate contains the source map information.
// 2. This span comes from our own crate. No special hamdling is needed - we just
// write `TAG_VALID_SPAN_LOCAL` to let the deserializer know that it should use
// our own source map information.
//
// If we're a proc-macro crate, we always treat this as a local `Span`.
// In `encode_source_map`, we serialize foreign `SourceFile`s into our metadata
// if we're a proc-macro crate.
// This allows us to avoid loading the dependencies of proc-macro crates: all of
// the information we need to decode `Span`s is stored in the proc-macro crate.
let (tag, lo, hi) = if s.source_file_cache.0.is_imported() && !s.is_proc_macro {
// To simplify deserialization, we 'rebase' this span onto the crate it originally came from
// (the crate that 'owns' the file it references. These rebased 'lo' and 'hi' values
// are relative to the source map information for the 'foreign' crate whose CrateNum
// we write into the metadata. This allows `imported_source_files` to binary
// search through the 'foreign' crate's source map information, using the
// deserialized 'lo' and 'hi' values directly.
//
// All of this logic ensures that the final result of deserialization is a 'normal'
// Span that can be used without any additional trouble.
let external_start_pos = {
// Introduce a new scope so that we drop the 'lock()' temporary
match &*s.source_file_cache.0.external_src.lock() {
ExternalSource::Foreign { original_start_pos, .. } => *original_start_pos,
src => panic!("Unexpected external source {:?}", src),
}
};
let lo = (span.lo - s.source_file_cache.0.start_pos) + external_start_pos;
let hi = (span.hi - s.source_file_cache.0.start_pos) + external_start_pos;
(TAG_VALID_SPAN_FOREIGN, lo, hi)
} else {
(TAG_VALID_SPAN_LOCAL, span.lo, span.hi)
};
tag.encode(s)?;
lo.encode(s)?;
// Encode length which is usually less than span.hi and profits more
// from the variable-length integer encoding that we use.
let len = hi - lo;
len.encode(s)?;
// Don't serialize any `SyntaxContext`s from a proc-macro crate,
// since we don't load proc-macro dependencies during serialization.
// This means that any hygiene information from macros used *within*
// a proc-macro crate (e.g. invoking a macro that expands to a proc-macro
// definition) will be lost.
//
// This can show up in two ways:
//
// 1. Any hygiene information associated with identifier of
// a proc macro (e.g. `#[proc_macro] pub fn $name`) will be lost.
// Since proc-macros can only be invoked from a different crate,
// real code should never need to care about this.
//
// 2. Using `Span::def_site` or `Span::mixed_site` will not
// include any hygiene information associated with the definition
// site. This means that a proc-macro cannot emit a `$crate`
// identifier which resolves to one of its dependencies,
// which also should never come up in practice.
//
// Additionally, this affects `Span::parent`, and any other
// span inspection APIs that would otherwise allow traversing
// the `SyntaxContexts` associated with a span.
//
// None of these user-visible effects should result in any
// cross-crate inconsistencies (getting one behavior in the same
// crate, and a different behavior in another crate) due to the
// limited surface that proc-macros can expose.
//
// IMPORTANT: If this is ever changed, be sure to update
// `rustc_span::hygiene::raw_encode_expn_id` to handle
// encoding `ExpnData` for proc-macro crates.
if s.is_proc_macro {
SyntaxContext::root().encode(s)?;
} else {
span.ctxt.encode(s)?;
}
if tag == TAG_VALID_SPAN_FOREIGN {
// This needs to be two lines to avoid holding the `s.source_file_cache`
// while calling `cnum.encode(s)`
let cnum = s.source_file_cache.0.cnum;
cnum.encode(s)?;
}
Ok(())
}
}
impl<'a, 'tcx> FingerprintEncoder for EncodeContext<'a, 'tcx> {
fn encode_fingerprint(&mut self, f: &Fingerprint) -> Result<(), Self::Error> {
f.encode_opaque(&mut self.opaque)
}
}
impl<'a, 'tcx> TyEncoder<'tcx> for EncodeContext<'a, 'tcx> {
const CLEAR_CROSS_CRATE: bool = true;
fn position(&self) -> usize {
self.opaque.position()
}
fn tcx(&self) -> TyCtxt<'tcx> {
self.tcx
}
fn type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize> {
&mut self.type_shorthands
}
fn predicate_shorthands(&mut self) -> &mut FxHashMap<rustc_middle::ty::Predicate<'tcx>, usize> {
&mut self.predicate_shorthands
}
fn encode_alloc_id(
&mut self,
alloc_id: &rustc_middle::mir::interpret::AllocId,
) -> Result<(), Self::Error> {
let (index, _) = self.interpret_allocs.insert_full(*alloc_id);
index.encode(self)
}
}
impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for &'tcx [mir::abstract_const::Node<'tcx>] {
fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
(**self).encode(s)
}
}
impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for &'tcx [(ty::Predicate<'tcx>, Span)] {
fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
(**self).encode(s)
}
}
/// Helper trait to allow overloading `EncodeContext::lazy` for iterators.
trait EncodeContentsForLazy<'a, 'tcx, T: ?Sized + LazyMeta> {
fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) -> T::Meta;
}
impl<'a, 'tcx, T: Encodable<EncodeContext<'a, 'tcx>>> EncodeContentsForLazy<'a, 'tcx, T> for &T {
fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) {
self.encode(ecx).unwrap()
}
}
impl<'a, 'tcx, T: Encodable<EncodeContext<'a, 'tcx>>> EncodeContentsForLazy<'a, 'tcx, T> for T {
fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) {
self.encode(ecx).unwrap()
}
}
impl<'a, 'tcx, I, T: Encodable<EncodeContext<'a, 'tcx>>> EncodeContentsForLazy<'a, 'tcx, [T]> for I
where
I: IntoIterator,
I::Item: EncodeContentsForLazy<'a, 'tcx, T>,
{
fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) -> usize {
self.into_iter().map(|value| value.encode_contents_for_lazy(ecx)).count()
}
}
// Shorthand for `$self.$tables.$table.set($def_id.index, $self.lazy($value))`, which would
// normally need extra variables to avoid errors about multiple mutable borrows.
macro_rules! record {
($self:ident.$tables:ident.$table:ident[$def_id:expr] <- $value:expr) => {{
{
let value = $value;
let lazy = $self.lazy(value);
$self.$tables.$table.set($def_id.index, lazy);
}
}};
}
impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
fn emit_lazy_distance<T: ?Sized + LazyMeta>(
&mut self,
lazy: Lazy<T>,
) -> Result<(), <Self as Encoder>::Error> {
let min_end = lazy.position.get() + T::min_size(lazy.meta);
let distance = match self.lazy_state {
LazyState::NoNode => bug!("emit_lazy_distance: outside of a metadata node"),
LazyState::NodeStart(start) => {
let start = start.get();
assert!(min_end <= start);
start - min_end
}
LazyState::Previous(last_min_end) => {
assert!(
last_min_end <= lazy.position,
"make sure that the calls to `lazy*` \
are in the same order as the metadata fields",
);
lazy.position.get() - last_min_end.get()
}
};
self.lazy_state = LazyState::Previous(NonZeroUsize::new(min_end).unwrap());
self.emit_usize(distance)
}
fn lazy<T: ?Sized + LazyMeta>(
&mut self,
value: impl EncodeContentsForLazy<'a, 'tcx, T>,
) -> Lazy<T> {
let pos = NonZeroUsize::new(self.position()).unwrap();
assert_eq!(self.lazy_state, LazyState::NoNode);
self.lazy_state = LazyState::NodeStart(pos);
let meta = value.encode_contents_for_lazy(self);
self.lazy_state = LazyState::NoNode;
assert!(pos.get() + <T>::min_size(meta) <= self.position());
Lazy::from_position_and_meta(pos, meta)
}
fn encode_info_for_items(&mut self) {
let krate = self.tcx.hir().krate();
self.encode_info_for_mod(hir::CRATE_HIR_ID, &krate.item.module, &krate.item.attrs);
// Proc-macro crates only export proc-macro items, which are looked
// up using `proc_macro_data`
if self.is_proc_macro {
return;
}
krate.visit_all_item_likes(&mut self.as_deep_visitor());
for macro_def in krate.exported_macros {
self.visit_macro_def(macro_def);
}
}
fn encode_def_path_table(&mut self) {
let table = self.tcx.hir().definitions().def_path_table();
if self.is_proc_macro {
for def_index in std::iter::once(CRATE_DEF_INDEX)
.chain(self.tcx.hir().krate().proc_macros.iter().map(|p| p.owner.local_def_index))
{
let def_key = self.lazy(table.def_key(def_index));
let def_path_hash = self.lazy(table.def_path_hash(def_index));
self.tables.def_keys.set(def_index, def_key);
self.tables.def_path_hashes.set(def_index, def_path_hash);
}
} else {
for (def_index, def_key, def_path_hash) in table.enumerated_keys_and_path_hashes() {
let def_key = self.lazy(def_key);
let def_path_hash = self.lazy(def_path_hash);
self.tables.def_keys.set(def_index, def_key);
self.tables.def_path_hashes.set(def_index, def_path_hash);
}
}
}
fn encode_source_map(&mut self) -> Lazy<[rustc_span::SourceFile]> {
let source_map = self.tcx.sess.source_map();
let all_source_files = source_map.files();
let (working_dir, _cwd_remapped) = self.tcx.sess.working_dir.clone();
// By replacing the `Option` with `None`, we ensure that we can't
// accidentally serialize any more `Span`s after the source map encoding
// is done.
let required_source_files = self.required_source_files.take().unwrap();
let adapted = all_source_files
.iter()
.enumerate()
.filter(|(idx, source_file)| {
// Only serialize `SourceFile`s that were used
// during the encoding of a `Span`
required_source_files.contains(*idx) &&
// Don't serialize imported `SourceFile`s, unless
// we're in a proc-macro crate.
(!source_file.is_imported() || self.is_proc_macro)
})
.map(|(_, source_file)| {
let mut adapted = match source_file.name {
// This path of this SourceFile has been modified by
// path-remapping, so we use it verbatim (and avoid
// cloning the whole map in the process).
_ if source_file.name_was_remapped => source_file.clone(),
// Otherwise expand all paths to absolute paths because
// any relative paths are potentially relative to a
// wrong directory.
FileName::Real(ref name) => {
let name = name.stable_name();
let mut adapted = (**source_file).clone();
adapted.name = Path::new(&working_dir).join(name).into();
adapted.name_hash = {
let mut hasher: StableHasher = StableHasher::new();
adapted.name.hash(&mut hasher);
hasher.finish::<u128>()
};
Lrc::new(adapted)
}
// expanded code, not from a file
_ => source_file.clone(),
};
// We're serializing this `SourceFile` into our crate metadata,
// so mark it as coming from this crate.
// This also ensures that we don't try to deserialize the
// `CrateNum` for a proc-macro dependency - since proc macro
// dependencies aren't loaded when we deserialize a proc-macro,
// trying to remap the `CrateNum` would fail.
if self.is_proc_macro {
Lrc::make_mut(&mut adapted).cnum = LOCAL_CRATE;
}
adapted
})
.collect::<Vec<_>>();
self.lazy(adapted.iter().map(|rc| &**rc))
}
fn encode_crate_root(&mut self) -> Lazy<CrateRoot<'tcx>> {
let mut i = self.position();
// Encode the crate deps
let crate_deps = self.encode_crate_deps();
let dylib_dependency_formats = self.encode_dylib_dependency_formats();
let dep_bytes = self.position() - i;
// Encode the lib features.
i = self.position();
let lib_features = self.encode_lib_features();
let lib_feature_bytes = self.position() - i;
// Encode the language items.
i = self.position();
let lang_items = self.encode_lang_items();
let lang_items_missing = self.encode_lang_items_missing();
let lang_item_bytes = self.position() - i;
// Encode the diagnostic items.
i = self.position();
let diagnostic_items = self.encode_diagnostic_items();
let diagnostic_item_bytes = self.position() - i;
// Encode the native libraries used
i = self.position();
let native_libraries = self.encode_native_libraries();
let native_lib_bytes = self.position() - i;
let foreign_modules = self.encode_foreign_modules();
// Encode DefPathTable
i = self.position();
self.encode_def_path_table();
let def_path_table_bytes = self.position() - i;
// Encode the def IDs of impls, for coherence checking.
i = self.position();
let impls = self.encode_impls();
let impl_bytes = self.position() - i;
let tcx = self.tcx;
// Encode the items.
i = self.position();
self.encode_info_for_items();
let item_bytes = self.position() - i;
// Encode the allocation index
let interpret_alloc_index = {
let mut interpret_alloc_index = Vec::new();
let mut n = 0;
trace!("beginning to encode alloc ids");
loop {
let new_n = self.interpret_allocs.len();
// if we have found new ids, serialize those, too
if n == new_n {
// otherwise, abort
break;
}
trace!("encoding {} further alloc ids", new_n - n);
for idx in n..new_n {
let id = self.interpret_allocs[idx];
let pos = self.position() as u32;
interpret_alloc_index.push(pos);
interpret::specialized_encode_alloc_id(self, tcx, id).unwrap();
}
n = new_n;
}
self.lazy(interpret_alloc_index)
};
// Encode the proc macro data. This affects 'tables',
// so we need to do this before we encode the tables
i = self.position();
let proc_macro_data = self.encode_proc_macros();
let proc_macro_data_bytes = self.position() - i;
i = self.position();
let tables = self.tables.encode(&mut self.opaque);
let tables_bytes = self.position() - i;
// Encode exported symbols info. This is prefetched in `encode_metadata` so we encode
// this as late as possible to give the prefetching as much time as possible to complete.
i = self.position();
let exported_symbols = tcx.exported_symbols(LOCAL_CRATE);
let exported_symbols = self.encode_exported_symbols(&exported_symbols);
let exported_symbols_bytes = self.position() - i;
// Encode the hygiene data,
// IMPORTANT: this *must* be the last thing that we encode (other than `SourceMap`). The process
// of encoding other items (e.g. `optimized_mir`) may cause us to load
// data from the incremental cache. If this causes us to deserialize a `Span`,
// then we may load additional `SyntaxContext`s into the global `HygieneData`.
// Therefore, we need to encode the hygiene data last to ensure that we encode
// any `SyntaxContext`s that might be used.
i = self.position();
let (syntax_contexts, expn_data) = self.encode_hygiene();
let hygiene_bytes = self.position() - i;
// Encode source_map. This needs to be done last,
// since encoding `Span`s tells us which `SourceFiles` we actually
// need to encode.
i = self.position();
let source_map = self.encode_source_map();
let source_map_bytes = self.position() - i;
let attrs = tcx.hir().krate_attrs();
let has_default_lib_allocator = tcx.sess.contains_name(&attrs, sym::default_lib_allocator);
let root = self.lazy(CrateRoot {
name: tcx.crate_name(LOCAL_CRATE),
extra_filename: tcx.sess.opts.cg.extra_filename.clone(),
triple: tcx.sess.opts.target_triple.clone(),
hash: tcx.crate_hash(LOCAL_CRATE),
disambiguator: tcx.sess.local_crate_disambiguator(),
panic_strategy: tcx.sess.panic_strategy(),
edition: tcx.sess.edition(),
has_global_allocator: tcx.has_global_allocator(LOCAL_CRATE),
has_panic_handler: tcx.has_panic_handler(LOCAL_CRATE),
has_default_lib_allocator,
plugin_registrar_fn: tcx.plugin_registrar_fn(LOCAL_CRATE).map(|id| id.index),
proc_macro_data,
compiler_builtins: tcx.sess.contains_name(&attrs, sym::compiler_builtins),
needs_allocator: tcx.sess.contains_name(&attrs, sym::needs_allocator),
needs_panic_runtime: tcx.sess.contains_name(&attrs, sym::needs_panic_runtime),
no_builtins: tcx.sess.contains_name(&attrs, sym::no_builtins),
panic_runtime: tcx.sess.contains_name(&attrs, sym::panic_runtime),
profiler_runtime: tcx.sess.contains_name(&attrs, sym::profiler_runtime),
symbol_mangling_version: tcx.sess.opts.debugging_opts.symbol_mangling_version,
crate_deps,
dylib_dependency_formats,
lib_features,
lang_items,
diagnostic_items,
lang_items_missing,
native_libraries,
foreign_modules,
source_map,
impls,
exported_symbols,
interpret_alloc_index,
tables,
syntax_contexts,
expn_data,
});
let total_bytes = self.position();
if tcx.sess.meta_stats() {
let mut zero_bytes = 0;
for e in self.opaque.data.iter() {
if *e == 0 {
zero_bytes += 1;
}
}
println!("metadata stats:");
println!(" dep bytes: {}", dep_bytes);
println!(" lib feature bytes: {}", lib_feature_bytes);
println!(" lang item bytes: {}", lang_item_bytes);
println!(" diagnostic item bytes: {}", diagnostic_item_bytes);
println!(" native bytes: {}", native_lib_bytes);
println!(" source_map bytes: {}", source_map_bytes);
println!(" impl bytes: {}", impl_bytes);
println!(" exp. symbols bytes: {}", exported_symbols_bytes);
println!(" def-path table bytes: {}", def_path_table_bytes);
println!(" proc-macro-data-bytes: {}", proc_macro_data_bytes);
println!(" item bytes: {}", item_bytes);
println!(" table bytes: {}", tables_bytes);
println!(" hygiene bytes: {}", hygiene_bytes);
println!(" zero bytes: {}", zero_bytes);
println!(" total bytes: {}", total_bytes);
}
root
}
}
impl EncodeContext<'a, 'tcx> {
fn encode_variances_of(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_variances_of({:?})", def_id);
record!(self.tables.variances[def_id] <- &self.tcx.variances_of(def_id)[..]);
}
fn encode_item_type(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_item_type({:?})", def_id);
record!(self.tables.ty[def_id] <- self.tcx.type_of(def_id));
}
fn encode_enum_variant_info(&mut self, def: &ty::AdtDef, index: VariantIdx) {
let tcx = self.tcx;
let variant = &def.variants[index];
let def_id = variant.def_id;
debug!("EncodeContext::encode_enum_variant_info({:?})", def_id);
let data = VariantData {
ctor_kind: variant.ctor_kind,
discr: variant.discr,
ctor: variant.ctor_def_id.map(|did| did.index),
is_non_exhaustive: variant.is_field_list_non_exhaustive(),
};
record!(self.tables.kind[def_id] <- EntryKind::Variant(self.lazy(data)));
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
record!(self.tables.attributes[def_id] <- &self.tcx.get_attrs(def_id)[..]);
record!(self.tables.expn_that_defined[def_id] <- self.tcx.expansion_that_defined(def_id));
record!(self.tables.children[def_id] <- variant.fields.iter().map(|f| {
assert!(f.did.is_local());
f.did.index
}));
self.encode_ident_span(def_id, variant.ident);
self.encode_stability(def_id);
self.encode_deprecation(def_id);
self.encode_item_type(def_id);
if variant.ctor_kind == CtorKind::Fn {
// FIXME(eddyb) encode signature only in `encode_enum_variant_ctor`.
if let Some(ctor_def_id) = variant.ctor_def_id {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(ctor_def_id));
}
// FIXME(eddyb) is this ever used?
self.encode_variances_of(def_id);
}
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
self.encode_optimized_mir(def_id.expect_local());
self.encode_promoted_mir(def_id.expect_local());
}
fn encode_enum_variant_ctor(&mut self, def: &ty::AdtDef, index: VariantIdx) {
let tcx = self.tcx;
let variant = &def.variants[index];
let def_id = variant.ctor_def_id.unwrap();
debug!("EncodeContext::encode_enum_variant_ctor({:?})", def_id);
// FIXME(eddyb) encode only the `CtorKind` for constructors.
let data = VariantData {
ctor_kind: variant.ctor_kind,
discr: variant.discr,
ctor: Some(def_id.index),
is_non_exhaustive: variant.is_field_list_non_exhaustive(),
};
record!(self.tables.kind[def_id] <- EntryKind::Variant(self.lazy(data)));
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
self.encode_stability(def_id);
self.encode_deprecation(def_id);
self.encode_item_type(def_id);
if variant.ctor_kind == CtorKind::Fn {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
self.encode_variances_of(def_id);
}
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
self.encode_optimized_mir(def_id.expect_local());
self.encode_promoted_mir(def_id.expect_local());
}
fn encode_info_for_mod(&mut self, id: hir::HirId, md: &hir::Mod<'_>, attrs: &[ast::Attribute]) {
let tcx = self.tcx;
let local_def_id = tcx.hir().local_def_id(id);
let def_id = local_def_id.to_def_id();
debug!("EncodeContext::encode_info_for_mod({:?})", def_id);
// If we are encoding a proc-macro crates, `encode_info_for_mod` will
// only ever get called for the crate root. We still want to encode
// the crate root for consistency with other crates (some of the resolver
// code uses it). However, we skip encoding anything relating to child
// items - we encode information about proc-macros later on.
let reexports = if !self.is_proc_macro {
match tcx.module_exports(local_def_id) {
Some(exports) => {
let hir = self.tcx.hir();
self.lazy(
exports
.iter()
.map(|export| export.map_id(|id| hir.local_def_id_to_hir_id(id))),
)
}
_ => Lazy::empty(),
}
} else {
Lazy::empty()
};
let data = ModData {
reexports,
expansion: tcx.hir().definitions().expansion_that_defined(local_def_id),
};
record!(self.tables.kind[def_id] <- EntryKind::Mod(self.lazy(data)));
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
record!(self.tables.attributes[def_id] <- attrs);
if self.is_proc_macro {
record!(self.tables.children[def_id] <- &[]);
} else {
record!(self.tables.children[def_id] <- md.item_ids.iter().map(|item_id| {
tcx.hir().local_def_id(item_id.id).local_def_index
}));
}
self.encode_stability(def_id);
self.encode_deprecation(def_id);
}
fn encode_field(
&mut self,
adt_def: &ty::AdtDef,
variant_index: VariantIdx,
field_index: usize,
) {
let tcx = self.tcx;
let variant = &adt_def.variants[variant_index];
let field = &variant.fields[field_index];
let def_id = field.did;
debug!("EncodeContext::encode_field({:?})", def_id);
let variant_id = tcx.hir().local_def_id_to_hir_id(variant.def_id.expect_local());
let variant_data = tcx.hir().expect_variant_data(variant_id);
record!(self.tables.kind[def_id] <- EntryKind::Field);
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
record!(self.tables.attributes[def_id] <- variant_data.fields()[field_index].attrs);
record!(self.tables.expn_that_defined[def_id] <- self.tcx.expansion_that_defined(def_id));
self.encode_ident_span(def_id, field.ident);
self.encode_stability(def_id);
self.encode_deprecation(def_id);
self.encode_item_type(def_id);
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
}
fn encode_struct_ctor(&mut self, adt_def: &ty::AdtDef, def_id: DefId) {
debug!("EncodeContext::encode_struct_ctor({:?})", def_id);
let tcx = self.tcx;
let variant = adt_def.non_enum_variant();
let data = VariantData {
ctor_kind: variant.ctor_kind,
discr: variant.discr,
ctor: Some(def_id.index),
is_non_exhaustive: variant.is_field_list_non_exhaustive(),
};
record!(self.tables.kind[def_id] <- EntryKind::Struct(self.lazy(data), adt_def.repr));
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
record!(self.tables.expn_that_defined[def_id] <- self.tcx.expansion_that_defined(def_id));
self.encode_stability(def_id);
self.encode_deprecation(def_id);
self.encode_item_type(def_id);
if variant.ctor_kind == CtorKind::Fn {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
self.encode_variances_of(def_id);
}
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
self.encode_optimized_mir(def_id.expect_local());
self.encode_promoted_mir(def_id.expect_local());
}
fn encode_generics(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_generics({:?})", def_id);
record!(self.tables.generics[def_id] <- self.tcx.generics_of(def_id));
}
fn encode_explicit_predicates(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_explicit_predicates({:?})", def_id);
record!(self.tables.explicit_predicates[def_id] <-
self.tcx.explicit_predicates_of(def_id));
}
fn encode_inferred_outlives(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_inferred_outlives({:?})", def_id);
let inferred_outlives = self.tcx.inferred_outlives_of(def_id);
if !inferred_outlives.is_empty() {
record!(self.tables.inferred_outlives[def_id] <- inferred_outlives);
}
}
fn encode_super_predicates(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_super_predicates({:?})", def_id);
record!(self.tables.super_predicates[def_id] <- self.tcx.super_predicates_of(def_id));
}
fn encode_explicit_item_bounds(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_explicit_item_bounds({:?})", def_id);
let bounds = self.tcx.explicit_item_bounds(def_id);
if !bounds.is_empty() {
record!(self.tables.explicit_item_bounds[def_id] <- bounds);
}
}
fn encode_info_for_trait_item(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_info_for_trait_item({:?})", def_id);
let tcx = self.tcx;
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
let ast_item = tcx.hir().expect_trait_item(hir_id);
let trait_item = tcx.associated_item(def_id);
let container = match trait_item.defaultness {
hir::Defaultness::Default { has_value: true } => AssocContainer::TraitWithDefault,
hir::Defaultness::Default { has_value: false } => AssocContainer::TraitRequired,
hir::Defaultness::Final => span_bug!(ast_item.span, "traits cannot have final items"),
};
record!(self.tables.kind[def_id] <- match trait_item.kind {
ty::AssocKind::Const => {
let rendered = rustc_hir_pretty::to_string(
&(&self.tcx.hir() as &dyn intravisit::Map<'_>),
|s| s.print_trait_item(ast_item)
);
let rendered_const = self.lazy(RenderedConst(rendered));
EntryKind::AssocConst(
container,
Default::default(),
rendered_const,
)
}
ty::AssocKind::Fn => {
let fn_data = if let hir::TraitItemKind::Fn(m_sig, m) = &ast_item.kind {
let param_names = match *m {
hir::TraitFn::Required(ref names) => {
self.encode_fn_param_names(names)
}
hir::TraitFn::Provided(body) => {
self.encode_fn_param_names_for_body(body)
}
};
FnData {
asyncness: m_sig.header.asyncness,
constness: hir::Constness::NotConst,
param_names,
}
} else {
bug!()
};
EntryKind::AssocFn(self.lazy(AssocFnData {
fn_data,
container,
has_self: trait_item.fn_has_self_parameter,
}))
}
ty::AssocKind::Type => {
self.encode_explicit_item_bounds(def_id);
EntryKind::AssocType(container)
}
});
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- ast_item.span);
record!(self.tables.attributes[def_id] <- ast_item.attrs);
self.encode_ident_span(def_id, ast_item.ident);
self.encode_stability(def_id);
self.encode_const_stability(def_id);
self.encode_deprecation(def_id);
match trait_item.kind {
ty::AssocKind::Const | ty::AssocKind::Fn => {
self.encode_item_type(def_id);
}
ty::AssocKind::Type => {
if trait_item.defaultness.has_value() {
self.encode_item_type(def_id);
}
}
}
if trait_item.kind == ty::AssocKind::Fn {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
self.encode_variances_of(def_id);
}
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
// This should be kept in sync with `PrefetchVisitor.visit_trait_item`.
self.encode_optimized_mir(def_id.expect_local());
self.encode_promoted_mir(def_id.expect_local());
}
fn metadata_output_only(&self) -> bool {
// MIR optimisation can be skipped when we're just interested in the metadata.
!self.tcx.sess.opts.output_types.should_codegen()
}
fn encode_info_for_impl_item(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_info_for_impl_item({:?})", def_id);
let tcx = self.tcx;
let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
let ast_item = self.tcx.hir().expect_impl_item(hir_id);
let impl_item = self.tcx.associated_item(def_id);
let container = match impl_item.defaultness {
hir::Defaultness::Default { has_value: true } => AssocContainer::ImplDefault,
hir::Defaultness::Final => AssocContainer::ImplFinal,
hir::Defaultness::Default { has_value: false } => {
span_bug!(ast_item.span, "impl items always have values (currently)")
}
};
record!(self.tables.kind[def_id] <- match impl_item.kind {
ty::AssocKind::Const => {
if let hir::ImplItemKind::Const(_, body_id) = ast_item.kind {
let qualifs = self.tcx.at(ast_item.span).mir_const_qualif(def_id);
EntryKind::AssocConst(
container,
qualifs,
self.encode_rendered_const_for_body(body_id))
} else {
bug!()
}
}
ty::AssocKind::Fn => {
let fn_data = if let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind {
FnData {
asyncness: sig.header.asyncness,
constness: sig.header.constness,
param_names: self.encode_fn_param_names_for_body(body),
}
} else {
bug!()
};
EntryKind::AssocFn(self.lazy(AssocFnData {
fn_data,
container,
has_self: impl_item.fn_has_self_parameter,
}))
}
ty::AssocKind::Type => EntryKind::AssocType(container)
});
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- ast_item.span);
record!(self.tables.attributes[def_id] <- ast_item.attrs);
self.encode_ident_span(def_id, impl_item.ident);
self.encode_stability(def_id);
self.encode_const_stability(def_id);
self.encode_deprecation(def_id);
self.encode_item_type(def_id);
if impl_item.kind == ty::AssocKind::Fn {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
self.encode_variances_of(def_id);
}
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
// The following part should be kept in sync with `PrefetchVisitor.visit_impl_item`.
let mir = match ast_item.kind {
hir::ImplItemKind::Const(..) => true,
hir::ImplItemKind::Fn(ref sig, _) => {
let generics = self.tcx.generics_of(def_id);
let needs_inline = (generics.requires_monomorphization(self.tcx)
|| tcx.codegen_fn_attrs(def_id).requests_inline())
&& !self.metadata_output_only();
let is_const_fn = sig.header.constness == hir::Constness::Const;
let always_encode_mir = self.tcx.sess.opts.debugging_opts.always_encode_mir;
needs_inline || is_const_fn || always_encode_mir
}
hir::ImplItemKind::TyAlias(..) => false,
};
if mir {
self.encode_optimized_mir(def_id.expect_local());
self.encode_promoted_mir(def_id.expect_local());
}
}
fn encode_fn_param_names_for_body(&mut self, body_id: hir::BodyId) -> Lazy<[Ident]> {
self.lazy(self.tcx.hir().body_param_names(body_id))
}
fn encode_fn_param_names(&mut self, param_names: &[Ident]) -> Lazy<[Ident]> {
self.lazy(param_names.iter())
}
fn encode_optimized_mir(&mut self, def_id: LocalDefId) {
debug!("EntryBuilder::encode_mir({:?})", def_id);
if self.tcx.mir_keys(LOCAL_CRATE).contains(&def_id) {
record!(self.tables.mir[def_id.to_def_id()] <- self.tcx.optimized_mir(def_id));
let unused = self.tcx.unused_generic_params(def_id);
if !unused.is_empty() {
record!(self.tables.unused_generic_params[def_id.to_def_id()] <- unused);
}
let abstract_const = self.tcx.mir_abstract_const(def_id);
if let Ok(Some(abstract_const)) = abstract_const {
record!(self.tables.mir_abstract_consts[def_id.to_def_id()] <- abstract_const);
}
}
}
fn encode_promoted_mir(&mut self, def_id: LocalDefId) {
debug!("EncodeContext::encode_promoted_mir({:?})", def_id);
if self.tcx.mir_keys(LOCAL_CRATE).contains(&def_id) {
record!(self.tables.promoted_mir[def_id.to_def_id()] <- self.tcx.promoted_mir(def_id));
}
}
// Encodes the inherent implementations of a structure, enumeration, or trait.
fn encode_inherent_implementations(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_inherent_implementations({:?})", def_id);
let implementations = self.tcx.inherent_impls(def_id);
if !implementations.is_empty() {
record!(self.tables.inherent_impls[def_id] <- implementations.iter().map(|&def_id| {
assert!(def_id.is_local());
def_id.index
}));
}
}
fn encode_stability(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_stability({:?})", def_id);
// The query lookup can take a measurable amount of time in crates with many items. Check if
// the stability attributes are even enabled before using their queries.
if self.feat.staged_api || self.tcx.sess.opts.debugging_opts.force_unstable_if_unmarked {
if let Some(stab) = self.tcx.lookup_stability(def_id) {
record!(self.tables.stability[def_id] <- stab)
}
}
}
fn encode_const_stability(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_const_stability({:?})", def_id);
// The query lookup can take a measurable amount of time in crates with many items. Check if
// the stability attributes are even enabled before using their queries.
if self.feat.staged_api || self.tcx.sess.opts.debugging_opts.force_unstable_if_unmarked {
if let Some(stab) = self.tcx.lookup_const_stability(def_id) {
record!(self.tables.const_stability[def_id] <- stab)
}
}
}
fn encode_deprecation(&mut self, def_id: DefId) {
debug!("EncodeContext::encode_deprecation({:?})", def_id);
if let Some(depr) = self.tcx.lookup_deprecation(def_id) {
record!(self.tables.deprecation[def_id] <- depr);
}
}
fn encode_rendered_const_for_body(&mut self, body_id: hir::BodyId) -> Lazy<RenderedConst> {
let hir = self.tcx.hir();
let body = hir.body(body_id);
let rendered = rustc_hir_pretty::to_string(&(&hir as &dyn intravisit::Map<'_>), |s| {
s.print_expr(&body.value)
});
let rendered_const = &RenderedConst(rendered);
self.lazy(rendered_const)
}
fn encode_info_for_item(&mut self, def_id: DefId, item: &'tcx hir::Item<'tcx>) {
let tcx = self.tcx;
debug!("EncodeContext::encode_info_for_item({:?})", def_id);
self.encode_ident_span(def_id, item.ident);
record!(self.tables.kind[def_id] <- match item.kind {
hir::ItemKind::Static(_, hir::Mutability::Mut, _) => EntryKind::MutStatic,
hir::ItemKind::Static(_, hir::Mutability::Not, _) => EntryKind::ImmStatic,
hir::ItemKind::Const(_, body_id) => {
let qualifs = self.tcx.at(item.span).mir_const_qualif(def_id);
EntryKind::Const(
qualifs,
self.encode_rendered_const_for_body(body_id)
)
}
hir::ItemKind::Fn(ref sig, .., body) => {
let data = FnData {
asyncness: sig.header.asyncness,
constness: sig.header.constness,
param_names: self.encode_fn_param_names_for_body(body),
};
EntryKind::Fn(self.lazy(data))
}
hir::ItemKind::Mod(ref m) => {
return self.encode_info_for_mod(item.hir_id, m, &item.attrs);
}
hir::ItemKind::ForeignMod(_) => EntryKind::ForeignMod,
hir::ItemKind::GlobalAsm(..) => EntryKind::GlobalAsm,
hir::ItemKind::TyAlias(..) => EntryKind::Type,
hir::ItemKind::OpaqueTy(..) => {
self.encode_explicit_item_bounds(def_id);
EntryKind::OpaqueTy
}
hir::ItemKind::Enum(..) => EntryKind::Enum(self.tcx.adt_def(def_id).repr),
hir::ItemKind::Struct(ref struct_def, _) => {
let adt_def = self.tcx.adt_def(def_id);
let variant = adt_def.non_enum_variant();
// Encode def_ids for each field and method
// for methods, write all the stuff get_trait_method
// needs to know
let ctor = struct_def.ctor_hir_id().map(|ctor_hir_id| {
self.tcx.hir().local_def_id(ctor_hir_id).local_def_index
});
EntryKind::Struct(self.lazy(VariantData {
ctor_kind: variant.ctor_kind,
discr: variant.discr,
ctor,
is_non_exhaustive: variant.is_field_list_non_exhaustive(),
}), adt_def.repr)
}
hir::ItemKind::Union(..) => {
let adt_def = self.tcx.adt_def(def_id);
let variant = adt_def.non_enum_variant();
EntryKind::Union(self.lazy(VariantData {
ctor_kind: variant.ctor_kind,
discr: variant.discr,
ctor: None,
is_non_exhaustive: variant.is_field_list_non_exhaustive(),
}), adt_def.repr)
}
hir::ItemKind::Impl { defaultness, .. } => {
let trait_ref = self.tcx.impl_trait_ref(def_id);
let polarity = self.tcx.impl_polarity(def_id);
let parent = if let Some(trait_ref) = trait_ref {
let trait_def = self.tcx.trait_def(trait_ref.def_id);
trait_def.ancestors(self.tcx, def_id).ok()
.and_then(|mut an| an.nth(1).and_then(|node| {
match node {
specialization_graph::Node::Impl(parent) => Some(parent),
_ => None,
}
}))
} else {
None
};
// if this is an impl of `CoerceUnsized`, create its
// "unsized info", else just store None
let coerce_unsized_info =
trait_ref.and_then(|t| {
if Some(t.def_id) == self.tcx.lang_items().coerce_unsized_trait() {
Some(self.tcx.at(item.span).coerce_unsized_info(def_id))
} else {
None
}
});
let data = ImplData {
polarity,
defaultness,
parent_impl: parent,
coerce_unsized_info,
};
EntryKind::Impl(self.lazy(data))
}
hir::ItemKind::Trait(..) => {
let trait_def = self.tcx.trait_def(def_id);
let data = TraitData {
unsafety: trait_def.unsafety,
paren_sugar: trait_def.paren_sugar,
has_auto_impl: self.tcx.trait_is_auto(def_id),
is_marker: trait_def.is_marker,
specialization_kind: trait_def.specialization_kind,
};
EntryKind::Trait(self.lazy(data))
}
hir::ItemKind::TraitAlias(..) => EntryKind::TraitAlias,
hir::ItemKind::ExternCrate(_) |
hir::ItemKind::Use(..) => bug!("cannot encode info for item {:?}", item),
});
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
record!(self.tables.attributes[def_id] <- item.attrs);
record!(self.tables.expn_that_defined[def_id] <- self.tcx.expansion_that_defined(def_id));
// FIXME(eddyb) there should be a nicer way to do this.
match item.kind {
hir::ItemKind::ForeignMod(ref fm) => record!(self.tables.children[def_id] <-
fm.items
.iter()
.map(|foreign_item| tcx.hir().local_def_id(
foreign_item.hir_id).local_def_index)
),
hir::ItemKind::Enum(..) => record!(self.tables.children[def_id] <-
self.tcx.adt_def(def_id).variants.iter().map(|v| {
assert!(v.def_id.is_local());
v.def_id.index
})
),
hir::ItemKind::Struct(..) | hir::ItemKind::Union(..) => {
record!(self.tables.children[def_id] <-
self.tcx.adt_def(def_id).non_enum_variant().fields.iter().map(|f| {
assert!(f.did.is_local());
f.did.index
})
)
}
hir::ItemKind::Impl { .. } | hir::ItemKind::Trait(..) => {
let associated_item_def_ids = self.tcx.associated_item_def_ids(def_id);
record!(self.tables.children[def_id] <-
associated_item_def_ids.iter().map(|&def_id| {
assert!(def_id.is_local());
def_id.index
})
);
}
_ => {}
}
self.encode_stability(def_id);
self.encode_const_stability(def_id);
self.encode_deprecation(def_id);
match item.kind {
hir::ItemKind::Static(..)
| hir::ItemKind::Const(..)
| hir::ItemKind::Fn(..)
| hir::ItemKind::TyAlias(..)
| hir::ItemKind::OpaqueTy(..)
| hir::ItemKind::Enum(..)
| hir::ItemKind::Struct(..)
| hir::ItemKind::Union(..)
| hir::ItemKind::Impl { .. } => self.encode_item_type(def_id),
_ => {}
}
if let hir::ItemKind::Fn(..) = item.kind {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
}
if let hir::ItemKind::Impl { .. } = item.kind {
if let Some(trait_ref) = self.tcx.impl_trait_ref(def_id) {
record!(self.tables.impl_trait_ref[def_id] <- trait_ref);
}
}
self.encode_inherent_implementations(def_id);
match item.kind {
hir::ItemKind::Enum(..)
| hir::ItemKind::Struct(..)
| hir::ItemKind::Union(..)
| hir::ItemKind::Fn(..) => self.encode_variances_of(def_id),
_ => {}
}
match item.kind {
hir::ItemKind::Static(..)
| hir::ItemKind::Const(..)
| hir::ItemKind::Fn(..)
| hir::ItemKind::TyAlias(..)
| hir::ItemKind::Enum(..)
| hir::ItemKind::Struct(..)
| hir::ItemKind::Union(..)
| hir::ItemKind::Impl { .. }
| hir::ItemKind::OpaqueTy(..)
| hir::ItemKind::Trait(..)
| hir::ItemKind::TraitAlias(..) => {
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
}
_ => {}
}
match item.kind {
hir::ItemKind::Trait(..) | hir::ItemKind::TraitAlias(..) => {
self.encode_super_predicates(def_id);
}
_ => {}
}
// The following part should be kept in sync with `PrefetchVisitor.visit_item`.
let mir = match item.kind {
hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => true,
hir::ItemKind::Fn(ref sig, ..) => {
let generics = tcx.generics_of(def_id);
let needs_inline = (generics.requires_monomorphization(tcx)
|| tcx.codegen_fn_attrs(def_id).requests_inline())
&& !self.metadata_output_only();
let always_encode_mir = self.tcx.sess.opts.debugging_opts.always_encode_mir;
needs_inline || sig.header.constness == hir::Constness::Const || always_encode_mir
}
_ => false,
};
if mir {
self.encode_optimized_mir(def_id.expect_local());
self.encode_promoted_mir(def_id.expect_local());
}
}
/// Serialize the text of exported macros
fn encode_info_for_macro_def(&mut self, macro_def: &hir::MacroDef<'_>) {
let def_id = self.tcx.hir().local_def_id(macro_def.hir_id).to_def_id();
record!(self.tables.kind[def_id] <- EntryKind::MacroDef(self.lazy(macro_def.ast.clone())));
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- macro_def.span);
record!(self.tables.attributes[def_id] <- macro_def.attrs);
self.encode_ident_span(def_id, macro_def.ident);
self.encode_stability(def_id);
self.encode_deprecation(def_id);
}
fn encode_info_for_generic_param(&mut self, def_id: DefId, kind: EntryKind, encode_type: bool) {
record!(self.tables.kind[def_id] <- kind);
record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
if encode_type {
self.encode_item_type(def_id);
}
}
fn encode_info_for_closure(&mut self, def_id: LocalDefId) {
debug!("EncodeContext::encode_info_for_closure({:?})", def_id);
// NOTE(eddyb) `tcx.type_of(def_id)` isn't used because it's fully generic,
// including on the signature, which is inferred in `typeck.
let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
let ty = self.tcx.typeck(def_id).node_type(hir_id);
record!(self.tables.kind[def_id.to_def_id()] <- match ty.kind() {
ty::Generator(..) => {
let data = self.tcx.generator_kind(def_id).unwrap();
EntryKind::Generator(data)
}
ty::Closure(..) => EntryKind::Closure,
_ => bug!("closure that is neither generator nor closure"),
});
record!(self.tables.span[def_id.to_def_id()] <- self.tcx.def_span(def_id));
record!(self.tables.attributes[def_id.to_def_id()] <- &self.tcx.get_attrs(def_id.to_def_id())[..]);
self.encode_item_type(def_id.to_def_id());
if let ty::Closure(def_id, substs) = *ty.kind() {
record!(self.tables.fn_sig[def_id] <- substs.as_closure().sig());
}
self.encode_generics(def_id.to_def_id());
self.encode_optimized_mir(def_id);
self.encode_promoted_mir(def_id);
}
fn encode_info_for_anon_const(&mut self, def_id: LocalDefId) {
debug!("EncodeContext::encode_info_for_anon_const({:?})", def_id);
let id = self.tcx.hir().local_def_id_to_hir_id(def_id);
let body_id = self.tcx.hir().body_owned_by(id);
let const_data = self.encode_rendered_const_for_body(body_id);
let qualifs = self.tcx.mir_const_qualif(def_id);
record!(self.tables.kind[def_id.to_def_id()] <- EntryKind::AnonConst(qualifs, const_data));
record!(self.tables.span[def_id.to_def_id()] <- self.tcx.def_span(def_id));
self.encode_item_type(def_id.to_def_id());
self.encode_generics(def_id.to_def_id());
self.encode_explicit_predicates(def_id.to_def_id());
self.encode_inferred_outlives(def_id.to_def_id());
self.encode_optimized_mir(def_id);
self.encode_promoted_mir(def_id);
}
fn encode_native_libraries(&mut self) -> Lazy<[NativeLib]> {
empty_proc_macro!(self);
let used_libraries = self.tcx.native_libraries(LOCAL_CRATE);
self.lazy(used_libraries.iter().cloned())
}
fn encode_foreign_modules(&mut self) -> Lazy<[ForeignModule]> {
empty_proc_macro!(self);
let foreign_modules = self.tcx.foreign_modules(LOCAL_CRATE);
self.lazy(foreign_modules.iter().cloned())
}
fn encode_hygiene(&mut self) -> (SyntaxContextTable, ExpnDataTable) {
let mut syntax_contexts: TableBuilder<_, _> = Default::default();
let mut expn_data_table: TableBuilder<_, _> = Default::default();
let _: Result<(), !> = self.hygiene_ctxt.encode(
&mut (&mut *self, &mut syntax_contexts, &mut expn_data_table),
|(this, syntax_contexts, _), index, ctxt_data| {
syntax_contexts.set(index, this.lazy(ctxt_data));
Ok(())
},
|(this, _, expn_data_table), index, expn_data| {
expn_data_table.set(index, this.lazy(expn_data));
Ok(())
},
);
(syntax_contexts.encode(&mut self.opaque), expn_data_table.encode(&mut self.opaque))
}
fn encode_proc_macros(&mut self) -> Option<ProcMacroData> {
let is_proc_macro = self.tcx.sess.crate_types().contains(&CrateType::ProcMacro);
if is_proc_macro {
let tcx = self.tcx;
let hir = tcx.hir();
let proc_macro_decls_static = tcx.proc_macro_decls_static(LOCAL_CRATE).unwrap().index;
let stability = tcx.lookup_stability(DefId::local(CRATE_DEF_INDEX)).copied();
let macros = self.lazy(hir.krate().proc_macros.iter().map(|p| p.owner.local_def_index));
// Normally, this information is encoded when we walk the items
// defined in this crate. However, we skip doing that for proc-macro crates,
// so we manually encode just the information that we need
for proc_macro in &hir.krate().proc_macros {
let id = proc_macro.owner.local_def_index;
let span = self.lazy(hir.span(*proc_macro));
// Proc-macros may have attributes like `#[allow_internal_unstable]`,
// so downstream crates need access to them.
let attrs = self.lazy(hir.attrs(*proc_macro));
self.tables.span.set(id, span);
self.tables.attributes.set(id, attrs);
}
Some(ProcMacroData { proc_macro_decls_static, stability, macros })
} else {
None
}
}
fn encode_crate_deps(&mut self) -> Lazy<[CrateDep]> {
empty_proc_macro!(self);
let crates = self.tcx.crates();
let mut deps = crates
.iter()
.map(|&cnum| {
let dep = CrateDep {
name: self.tcx.original_crate_name(cnum),
hash: self.tcx.crate_hash(cnum),
host_hash: self.tcx.crate_host_hash(cnum),
kind: self.tcx.dep_kind(cnum),
extra_filename: self.tcx.extra_filename(cnum),
};
(cnum, dep)
})
.collect::<Vec<_>>();
deps.sort_by_key(|&(cnum, _)| cnum);
{
// Sanity-check the crate numbers
let mut expected_cnum = 1;
for &(n, _) in &deps {
assert_eq!(n, CrateNum::new(expected_cnum));
expected_cnum += 1;
}
}
// We're just going to write a list of crate 'name-hash-version's, with
// the assumption that they are numbered 1 to n.
// FIXME (#2166): This is not nearly enough to support correct versioning
// but is enough to get transitive crate dependencies working.
self.lazy(deps.iter().map(|&(_, ref dep)| dep))
}
fn encode_lib_features(&mut self) -> Lazy<[(Symbol, Option<Symbol>)]> {
empty_proc_macro!(self);
let tcx = self.tcx;
let lib_features = tcx.lib_features();
self.lazy(lib_features.to_vec())
}
fn encode_diagnostic_items(&mut self) -> Lazy<[(Symbol, DefIndex)]> {
empty_proc_macro!(self);
let tcx = self.tcx;
let diagnostic_items = tcx.diagnostic_items(LOCAL_CRATE);
self.lazy(diagnostic_items.iter().map(|(&name, def_id)| (name, def_id.index)))
}
fn encode_lang_items(&mut self) -> Lazy<[(DefIndex, usize)]> {
empty_proc_macro!(self);
let tcx = self.tcx;
let lang_items = tcx.lang_items();
let lang_items = lang_items.items().iter();
self.lazy(lang_items.enumerate().filter_map(|(i, &opt_def_id)| {
if let Some(def_id) = opt_def_id {
if def_id.is_local() {
return Some((def_id.index, i));
}
}
None
}))
}
fn encode_lang_items_missing(&mut self) -> Lazy<[lang_items::LangItem]> {
empty_proc_macro!(self);
let tcx = self.tcx;
self.lazy(&tcx.lang_items().missing)
}
/// Encodes an index, mapping each trait to its (local) implementations.
fn encode_impls(&mut self) -> Lazy<[TraitImpls]> {
empty_proc_macro!(self);
debug!("EncodeContext::encode_impls()");
let tcx = self.tcx;
let mut visitor = ImplVisitor { tcx, impls: FxHashMap::default() };
tcx.hir().krate().visit_all_item_likes(&mut visitor);
let mut all_impls: Vec<_> = visitor.impls.into_iter().collect();
// Bring everything into deterministic order for hashing
all_impls.sort_by_cached_key(|&(trait_def_id, _)| tcx.def_path_hash(trait_def_id));
let all_impls: Vec<_> = all_impls
.into_iter()
.map(|(trait_def_id, mut impls)| {
// Bring everything into deterministic order for hashing
impls.sort_by_cached_key(|&(index, _)| {
tcx.hir().definitions().def_path_hash(LocalDefId { local_def_index: index })
});
TraitImpls {
trait_id: (trait_def_id.krate.as_u32(), trait_def_id.index),
impls: self.lazy(&impls),
}
})
.collect();
self.lazy(&all_impls)
}
// Encodes all symbols exported from this crate into the metadata.
//
// This pass is seeded off the reachability list calculated in the
// middle::reachable module but filters out items that either don't have a
// symbol associated with them (they weren't translated) or if they're an FFI
// definition (as that's not defined in this crate).
fn encode_exported_symbols(
&mut self,
exported_symbols: &[(ExportedSymbol<'tcx>, SymbolExportLevel)],
) -> Lazy<[(ExportedSymbol<'tcx>, SymbolExportLevel)]> {
empty_proc_macro!(self);
// The metadata symbol name is special. It should not show up in
// downstream crates.
let metadata_symbol_name = SymbolName::new(self.tcx, &metadata_symbol_name(self.tcx));
self.lazy(
exported_symbols
.iter()
.filter(|&&(ref exported_symbol, _)| match *exported_symbol {
ExportedSymbol::NoDefId(symbol_name) => symbol_name != metadata_symbol_name,
_ => true,
})
.cloned(),
)
}
fn encode_dylib_dependency_formats(&mut self) -> Lazy<[Option<LinkagePreference>]> {
empty_proc_macro!(self);
let formats = self.tcx.dependency_formats(LOCAL_CRATE);
for (ty, arr) in formats.iter() {
if *ty != CrateType::Dylib {
continue;
}
return self.lazy(arr.iter().map(|slot| match *slot {
Linkage::NotLinked | Linkage::IncludedFromDylib => None,
Linkage::Dynamic => Some(LinkagePreference::RequireDynamic),
Linkage::Static => Some(LinkagePreference::RequireStatic),
}));
}
Lazy::empty()
}
fn encode_info_for_foreign_item(&mut self, def_id: DefId, nitem: &hir::ForeignItem<'_>) {
let tcx = self.tcx;
debug!("EncodeContext::encode_info_for_foreign_item({:?})", def_id);
record!(self.tables.kind[def_id] <- match nitem.kind {
hir::ForeignItemKind::Fn(_, ref names, _) => {
let data = FnData {
asyncness: hir::IsAsync::NotAsync,
constness: if self.tcx.is_const_fn_raw(def_id) {
hir::Constness::Const
} else {
hir::Constness::NotConst
},
param_names: self.encode_fn_param_names(names),
};
EntryKind::ForeignFn(self.lazy(data))
}
hir::ForeignItemKind::Static(_, hir::Mutability::Mut) => EntryKind::ForeignMutStatic,
hir::ForeignItemKind::Static(_, hir::Mutability::Not) => EntryKind::ForeignImmStatic,
hir::ForeignItemKind::Type => EntryKind::ForeignType,
});
record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
record!(self.tables.span[def_id] <- nitem.span);
record!(self.tables.attributes[def_id] <- nitem.attrs);
self.encode_ident_span(def_id, nitem.ident);
self.encode_stability(def_id);
self.encode_const_stability(def_id);
self.encode_deprecation(def_id);
self.encode_item_type(def_id);
self.encode_inherent_implementations(def_id);
if let hir::ForeignItemKind::Fn(..) = nitem.kind {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
self.encode_variances_of(def_id);
}
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
}
}
// FIXME(eddyb) make metadata encoding walk over all definitions, instead of HIR.
impl Visitor<'tcx> for EncodeContext<'a, 'tcx> {
type Map = Map<'tcx>;
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
NestedVisitorMap::OnlyBodies(self.tcx.hir())
}
fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
intravisit::walk_expr(self, ex);
self.encode_info_for_expr(ex);
}
fn visit_anon_const(&mut self, c: &'tcx AnonConst) {
intravisit::walk_anon_const(self, c);
let def_id = self.tcx.hir().local_def_id(c.hir_id);
self.encode_info_for_anon_const(def_id);
}
fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
intravisit::walk_item(self, item);
let def_id = self.tcx.hir().local_def_id(item.hir_id);
match item.kind {
hir::ItemKind::ExternCrate(_) | hir::ItemKind::Use(..) => {} // ignore these
_ => self.encode_info_for_item(def_id.to_def_id(), item),
}
self.encode_addl_info_for_item(item);
}
fn visit_foreign_item(&mut self, ni: &'tcx hir::ForeignItem<'tcx>) {
intravisit::walk_foreign_item(self, ni);
let def_id = self.tcx.hir().local_def_id(ni.hir_id);
self.encode_info_for_foreign_item(def_id.to_def_id(), ni);
}
fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
intravisit::walk_generics(self, generics);
self.encode_info_for_generics(generics);
}
fn visit_macro_def(&mut self, macro_def: &'tcx hir::MacroDef<'tcx>) {
self.encode_info_for_macro_def(macro_def);
}
}
impl EncodeContext<'a, 'tcx> {
fn encode_fields(&mut self, adt_def: &ty::AdtDef) {
for (variant_index, variant) in adt_def.variants.iter_enumerated() {
for (field_index, _field) in variant.fields.iter().enumerate() {
self.encode_field(adt_def, variant_index, field_index);
}
}
}
fn encode_info_for_generics(&mut self, generics: &hir::Generics<'tcx>) {
for param in generics.params {
let def_id = self.tcx.hir().local_def_id(param.hir_id);
match param.kind {
GenericParamKind::Lifetime { .. } => continue,
GenericParamKind::Type { ref default, .. } => {
self.encode_info_for_generic_param(
def_id.to_def_id(),
EntryKind::TypeParam,
default.is_some(),
);
if default.is_some() {
self.encode_stability(def_id.to_def_id());
}
}
GenericParamKind::Const { .. } => {
self.encode_info_for_generic_param(
def_id.to_def_id(),
EntryKind::ConstParam,
true,
);
// FIXME(const_generics:defaults)
}
}
}
}
fn encode_info_for_expr(&mut self, expr: &hir::Expr<'_>) {
if let hir::ExprKind::Closure(..) = expr.kind {
let def_id = self.tcx.hir().local_def_id(expr.hir_id);
self.encode_info_for_closure(def_id);
}
}
fn encode_ident_span(&mut self, def_id: DefId, ident: Ident) {
record!(self.tables.ident_span[def_id] <- ident.span);
}
/// In some cases, along with the item itself, we also
/// encode some sub-items. Usually we want some info from the item
/// so it's easier to do that here then to wait until we would encounter
/// normally in the visitor walk.
fn encode_addl_info_for_item(&mut self, item: &hir::Item<'_>) {
let def_id = self.tcx.hir().local_def_id(item.hir_id);
match item.kind {
hir::ItemKind::Static(..)
| hir::ItemKind::Const(..)
| hir::ItemKind::Fn(..)
| hir::ItemKind::Mod(..)
| hir::ItemKind::ForeignMod(..)
| hir::ItemKind::GlobalAsm(..)
| hir::ItemKind::ExternCrate(..)
| hir::ItemKind::Use(..)
| hir::ItemKind::TyAlias(..)
| hir::ItemKind::OpaqueTy(..)
| hir::ItemKind::TraitAlias(..) => {
// no sub-item recording needed in these cases
}
hir::ItemKind::Enum(..) => {
let def = self.tcx.adt_def(def_id.to_def_id());
self.encode_fields(def);
for (i, variant) in def.variants.iter_enumerated() {
self.encode_enum_variant_info(def, i);
if let Some(_ctor_def_id) = variant.ctor_def_id {
self.encode_enum_variant_ctor(def, i);
}
}
}
hir::ItemKind::Struct(ref struct_def, _) => {
let def = self.tcx.adt_def(def_id.to_def_id());
self.encode_fields(def);
// If the struct has a constructor, encode it.
if let Some(ctor_hir_id) = struct_def.ctor_hir_id() {
let ctor_def_id = self.tcx.hir().local_def_id(ctor_hir_id);
self.encode_struct_ctor(def, ctor_def_id.to_def_id());
}
}
hir::ItemKind::Union(..) => {
let def = self.tcx.adt_def(def_id.to_def_id());
self.encode_fields(def);
}
hir::ItemKind::Impl { .. } => {
for &trait_item_def_id in
self.tcx.associated_item_def_ids(def_id.to_def_id()).iter()
{
self.encode_info_for_impl_item(trait_item_def_id);
}
}
hir::ItemKind::Trait(..) => {
for &item_def_id in self.tcx.associated_item_def_ids(def_id.to_def_id()).iter() {
self.encode_info_for_trait_item(item_def_id);
}
}
}
}
}
struct ImplVisitor<'tcx> {
tcx: TyCtxt<'tcx>,
impls: FxHashMap<DefId, Vec<(DefIndex, Option<ty::fast_reject::SimplifiedType>)>>,
}
impl<'tcx, 'v> ItemLikeVisitor<'v> for ImplVisitor<'tcx> {
fn visit_item(&mut self, item: &hir::Item<'_>) {
if let hir::ItemKind::Impl { .. } = item.kind {
let impl_id = self.tcx.hir().local_def_id(item.hir_id);
if let Some(trait_ref) = self.tcx.impl_trait_ref(impl_id.to_def_id()) {
let simplified_self_ty =
ty::fast_reject::simplify_type(self.tcx, trait_ref.self_ty(), false);
self.impls
.entry(trait_ref.def_id)
.or_default()
.push((impl_id.local_def_index, simplified_self_ty));
}
}
}
fn visit_trait_item(&mut self, _trait_item: &'v hir::TraitItem<'v>) {}
fn visit_impl_item(&mut self, _impl_item: &'v hir::ImplItem<'v>) {
// handled in `visit_item` above
}
}
/// Used to prefetch queries which will be needed later by metadata encoding.
/// Only a subset of the queries are actually prefetched to keep this code smaller.
struct PrefetchVisitor<'tcx> {
tcx: TyCtxt<'tcx>,
mir_keys: &'tcx FxHashSet<LocalDefId>,
}
impl<'tcx> PrefetchVisitor<'tcx> {
fn prefetch_mir(&self, def_id: LocalDefId) {
if self.mir_keys.contains(&def_id) {
self.tcx.ensure().optimized_mir(def_id);
self.tcx.ensure().promoted_mir(def_id);
}
}
}
impl<'tcx, 'v> ParItemLikeVisitor<'v> for PrefetchVisitor<'tcx> {
fn visit_item(&self, item: &hir::Item<'_>) {
// This should be kept in sync with `encode_info_for_item`.
let tcx = self.tcx;
match item.kind {
hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => {
self.prefetch_mir(tcx.hir().local_def_id(item.hir_id))
}
hir::ItemKind::Fn(ref sig, ..) => {
let def_id = tcx.hir().local_def_id(item.hir_id);
let generics = tcx.generics_of(def_id.to_def_id());
let needs_inline = generics.requires_monomorphization(tcx)
|| tcx.codegen_fn_attrs(def_id.to_def_id()).requests_inline();
if needs_inline || sig.header.constness == hir::Constness::Const {
self.prefetch_mir(def_id)
}
}
_ => (),
}
}
fn visit_trait_item(&self, trait_item: &'v hir::TraitItem<'v>) {
// This should be kept in sync with `encode_info_for_trait_item`.
self.prefetch_mir(self.tcx.hir().local_def_id(trait_item.hir_id));
}
fn visit_impl_item(&self, impl_item: &'v hir::ImplItem<'v>) {
// This should be kept in sync with `encode_info_for_impl_item`.
let tcx = self.tcx;
match impl_item.kind {
hir::ImplItemKind::Const(..) => {
self.prefetch_mir(tcx.hir().local_def_id(impl_item.hir_id))
}
hir::ImplItemKind::Fn(ref sig, _) => {
let def_id = tcx.hir().local_def_id(impl_item.hir_id);
let generics = tcx.generics_of(def_id.to_def_id());
let needs_inline = generics.requires_monomorphization(tcx)
|| tcx.codegen_fn_attrs(def_id.to_def_id()).requests_inline();
let is_const_fn = sig.header.constness == hir::Constness::Const;
if needs_inline || is_const_fn {
self.prefetch_mir(def_id)
}
}
hir::ImplItemKind::TyAlias(..) => (),
}
}
}
// NOTE(eddyb) The following comment was preserved for posterity, even
// though it's no longer relevant as EBML (which uses nested & tagged
// "documents") was replaced with a scheme that can't go out of bounds.
//
// And here we run into yet another obscure archive bug: in which metadata
// loaded from archives may have trailing garbage bytes. Awhile back one of
// our tests was failing sporadically on the macOS 64-bit builders (both nopt
// and opt) by having ebml generate an out-of-bounds panic when looking at
// metadata.
//
// Upon investigation it turned out that the metadata file inside of an rlib
// (and ar archive) was being corrupted. Some compilations would generate a
// metadata file which would end in a few extra bytes, while other
// compilations would not have these extra bytes appended to the end. These
// extra bytes were interpreted by ebml as an extra tag, so they ended up
// being interpreted causing the out-of-bounds.
//
// The root cause of why these extra bytes were appearing was never
// discovered, and in the meantime the solution we're employing is to insert
// the length of the metadata to the start of the metadata. Later on this
// will allow us to slice the metadata to the precise length that we just
// generated regardless of trailing bytes that end up in it.
pub(super) fn encode_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
// Since encoding metadata is not in a query, and nothing is cached,
// there's no need to do dep-graph tracking for any of it.
tcx.dep_graph.assert_ignored();
join(
|| encode_metadata_impl(tcx),
|| {
if tcx.sess.threads() == 1 {
return;
}
// Prefetch some queries used by metadata encoding.
// This is not necessary for correctness, but is only done for performance reasons.
// It can be removed if it turns out to cause trouble or be detrimental to performance.
join(
|| {
if !tcx.sess.opts.output_types.should_codegen() {
// We won't emit MIR, so don't prefetch it.
return;
}
tcx.hir().krate().par_visit_all_item_likes(&PrefetchVisitor {
tcx,
mir_keys: tcx.mir_keys(LOCAL_CRATE),
});
},
|| tcx.exported_symbols(LOCAL_CRATE),
);
},
)
.0
}
fn encode_metadata_impl(tcx: TyCtxt<'_>) -> EncodedMetadata {
let mut encoder = opaque::Encoder::new(vec![]);
encoder.emit_raw_bytes(METADATA_HEADER);
// Will be filled with the root position after encoding everything.
encoder.emit_raw_bytes(&[0, 0, 0, 0]);
let source_map_files = tcx.sess.source_map().files();
let hygiene_ctxt = HygieneEncodeContext::default();
let mut ecx = EncodeContext {
opaque: encoder,
tcx,
feat: tcx.features(),
tables: Default::default(),
lazy_state: LazyState::NoNode,
type_shorthands: Default::default(),
predicate_shorthands: Default::default(),
source_file_cache: (source_map_files[0].clone(), 0),
interpret_allocs: Default::default(),
required_source_files: Some(GrowableBitSet::with_capacity(source_map_files.len())),
is_proc_macro: tcx.sess.crate_types().contains(&CrateType::ProcMacro),
hygiene_ctxt: &hygiene_ctxt,
};
drop(source_map_files);
// Encode the rustc version string in a predictable location.
rustc_version().encode(&mut ecx).unwrap();
// Encode all the entries and extra information in the crate,
// culminating in the `CrateRoot` which points to all of it.
let root = ecx.encode_crate_root();
let mut result = ecx.opaque.into_inner();
// Encode the root position.
let header = METADATA_HEADER.len();
let pos = root.position.get();
result[header + 0] = (pos >> 24) as u8;
result[header + 1] = (pos >> 16) as u8;
result[header + 2] = (pos >> 8) as u8;
result[header + 3] = (pos >> 0) as u8;
EncodedMetadata { raw_data: result }
}