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Auto merge of #66610 - alexreg:trait-upcasting-cosmetic, r=Centril

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Aggregation of drive-by cosmetic changes for trait-upcasting PR

Cherry-picked from #60900.

As requested by @Centril (and @nikomatsakis, I believe).

r? @Centril
This commit is contained in:
bors 2019-11-21 21:01:14 +00:00
commit f11759d38c
40 changed files with 647 additions and 639 deletions
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5
src/librustc/hir/mod.rs
View file

@ -1919,8 +1919,9 @@ pub enum ImplItemKind {
/// Bindings like `A: Debug` are represented as a special type `A =
/// $::Debug` that is understood by the astconv code.
///
/// FIXME(alexreg) -- why have a separate type for the binding case,
/// wouldn't it be better to make the `ty` field an enum like:
/// FIXME(alexreg): why have a separate type for the binding case,
/// wouldn't it be better to make the `ty` field an enum like the
/// following?
///
/// ```
/// enum TypeBindingKind {

8
src/librustc/infer/canonical/canonicalizer.rs
View file

@ -306,7 +306,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for Canonicalizer<'cx, 'tcx> {
match *r {
ty::ReLateBound(index, ..) => {
if index >= self.binder_index {
bug!("escaping late bound region during canonicalization")
bug!("escaping late-bound region during canonicalization");
} else {
r
}
@ -336,7 +336,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for Canonicalizer<'cx, 'tcx> {
.canonicalize_free_region(self, r),
ty::ReClosureBound(..) => {
bug!("closure bound region encountered during canonicalization")
bug!("closure bound region encountered during canonicalization");
}
}
}
@ -346,14 +346,14 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for Canonicalizer<'cx, 'tcx> {
ty::Infer(ty::TyVar(vid)) => {
debug!("canonical: type var found with vid {:?}", vid);
match self.infcx.unwrap().probe_ty_var(vid) {
// `t` could be a float / int variable: canonicalize that instead
// `t` could be a float / int variable; canonicalize that instead.
Ok(t) => {
debug!("(resolved to {:?})", t);
self.fold_ty(t)
}
// `TyVar(vid)` is unresolved, track its universe index in the canonicalized
// result
// result.
Err(mut ui) => {
if !self.infcx.unwrap().tcx.sess.opts.debugging_opts.chalk {
// FIXME: perf problem described in #55921.

14
src/librustc/infer/error_reporting/mod.rs
View file

@ -48,22 +48,24 @@
use super::lexical_region_resolve::RegionResolutionError;
use super::region_constraints::GenericKind;
use super::{InferCtxt, RegionVariableOrigin, SubregionOrigin, TypeTrace, ValuePairs};
use crate::infer::{self, SuppressRegionErrors};
use crate::hir;
use crate::hir::def_id::DefId;
use crate::hir::Node;
use crate::infer::{self, SuppressRegionErrors};
use crate::infer::opaque_types;
use crate::middle::region;
use crate::traits::{IfExpressionCause, MatchExpressionArmCause, ObligationCause};
use crate::traits::{ObligationCauseCode};
use crate::traits::{
IfExpressionCause, MatchExpressionArmCause, ObligationCause, ObligationCauseCode,
};
use crate::ty::error::TypeError;
use crate::ty::{self, subst::{Subst, SubstsRef}, Region, Ty, TyCtxt, TypeFoldable};
use errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString};
use std::{cmp, fmt};
use rustc_error_codes::*;
use syntax_pos::{Pos, Span};
use rustc_error_codes::*;
use std::{cmp, fmt};
mod note;
@ -1270,7 +1272,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
}
/// When encountering a case where `.as_ref()` on a `Result` or `Option` would be appropriate,
/// suggest it.
/// suggests it.
fn suggest_as_ref_where_appropriate(
&self,
span: Span,

2
src/librustc/infer/outlives/obligations.rs
View file

@ -221,7 +221,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
}
/// The `TypeOutlives` struct has the job of "lowering" a `T: 'a`
/// obligation into a series of `'a: 'b` constraints and "verifys", as
/// obligation into a series of `'a: 'b` constraints and "verify"s, as
/// described on the module comment. The final constraints are emitted
/// via a "delegate" of type `D` -- this is usually the `infcx`, which
/// accrues them into the `region_obligations` code, but for NLL we

15
src/librustc/mir/interpret/pointer.rs
View file

@ -1,11 +1,12 @@
use std::fmt::{self, Display};
use std::convert::TryFrom;
use super::{AllocId, InterpResult};
use crate::mir;
use crate::ty::layout::{self, HasDataLayout, Size};
use rustc_macros::HashStable;
use super::{AllocId, InterpResult};
use std::convert::TryFrom;
use std::fmt::{self, Display};
/// Used by `check_in_alloc` to indicate context of check
#[derive(Debug, Copy, Clone, RustcEncodable, RustcDecodable, HashStable)]
@ -74,8 +75,8 @@ pub trait PointerArithmetic: layout::HasDataLayout {
fn overflowing_signed_offset(&self, val: u64, i: i128) -> (u64, bool) {
// FIXME: is it possible to over/underflow here?
if i < 0 {
// Trickery to ensure that i64::min_value() works fine: compute n = -i.
// This formula only works for true negative values, it overflows for zero!
// Trickery to ensure that `i64::min_value()` works fine: compute `n = -i`.
// This formula only works for true negative values; it overflows for zero!
let n = u64::max_value() - (i as u64) + 1;
let res = val.overflowing_sub(n);
self.truncate_to_ptr(res)
@ -105,7 +106,7 @@ impl<T: layout::HasDataLayout> PointerArithmetic for T {}
///
/// Defaults to the index based and loosely coupled `AllocId`.
///
/// Pointer is also generic over the `Tag` associated with each pointer,
/// `Pointer` is also generic over the `Tag` associated with each pointer,
/// which is used to do provenance tracking during execution.
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd,
RustcEncodable, RustcDecodable, Hash, HashStable)]
@ -129,7 +130,7 @@ impl<Id: fmt::Debug> fmt::Debug for Pointer<(), Id> {
}
}
/// Produces a `Pointer` which points to the beginning of the `Allocation`.
/// Produces a `Pointer` that points to the beginning of the `Allocation`.
impl From<AllocId> for Pointer {
#[inline(always)]
fn from(alloc_id: AllocId) -> Self {

2
src/librustc/session/config.rs
View file

@ -1203,7 +1203,7 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options,
force_frame_pointers: Option<bool> = (None, parse_opt_bool, [TRACKED],
"force use of the frame pointers"),
debug_assertions: Option<bool> = (None, parse_opt_bool, [TRACKED],
"explicitly enable the cfg(debug_assertions) directive"),
"explicitly enable the `cfg(debug_assertions)` directive"),
inline_threshold: Option<usize> = (None, parse_opt_uint, [TRACKED],
"set the threshold for inlining a function (default: 225)"),
panic: Option<PanicStrategy> = (None, parse_panic_strategy,

170
src/librustc/traits/auto_trait.rs
View file

@ -1,18 +1,18 @@
//! Support code for rustdoc and external tools . You really don't
//! want to be using this unless you need to.
//! Support code for rustdoc and external tools.
//! You really don't want to be using this unless you need to.
use super::*;
use std::collections::hash_map::Entry;
use std::collections::VecDeque;
use crate::infer::region_constraints::{Constraint, RegionConstraintData};
use crate::infer::InferCtxt;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use crate::ty::fold::TypeFolder;
use crate::ty::{Region, RegionVid};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use std::collections::hash_map::Entry;
use std::collections::VecDeque;
// FIXME(twk): this is obviously not nice to duplicate like that
#[derive(Eq, PartialEq, Hash, Copy, Clone, Debug)]
pub enum RegionTarget<'tcx> {
@ -233,43 +233,45 @@ impl<'tcx> AutoTraitFinder<'tcx> {
}
impl AutoTraitFinder<'tcx> {
// The core logic responsible for computing the bounds for our synthesized impl.
//
// To calculate the bounds, we call SelectionContext.select in a loop. Like FulfillmentContext,
// we recursively select the nested obligations of predicates we encounter. However, whenever we
// encounter an UnimplementedError involving a type parameter, we add it to our ParamEnv. Since
// our goal is to determine when a particular type implements an auto trait, Unimplemented
// errors tell us what conditions need to be met.
//
// This method ends up working somewhat similarly to FulfillmentContext, but with a few key
// differences. FulfillmentContext works under the assumption that it's dealing with concrete
// user code. According, it considers all possible ways that a Predicate could be met - which
// isn't always what we want for a synthesized impl. For example, given the predicate 'T:
// Iterator', FulfillmentContext can end up reporting an Unimplemented error for T:
// IntoIterator - since there's an implementation of Iteratpr where T: IntoIterator,
// FulfillmentContext will drive SelectionContext to consider that impl before giving up. If we
// were to rely on FulfillmentContext's decision, we might end up synthesizing an impl like
// this:
// 'impl<T> Send for Foo<T> where T: IntoIterator'
//
// While it might be technically true that Foo implements Send where T: IntoIterator,
// the bound is overly restrictive - it's really only necessary that T: Iterator.
//
// For this reason, evaluate_predicates handles predicates with type variables specially. When
// we encounter an Unimplemented error for a bound such as 'T: Iterator', we immediately add it
// to our ParamEnv, and add it to our stack for recursive evaluation. When we later select it,
// we'll pick up any nested bounds, without ever inferring that 'T: IntoIterator' needs to
// hold.
//
// One additional consideration is supertrait bounds. Normally, a ParamEnv is only ever
// constructed once for a given type. As part of the construction process, the ParamEnv will
// have any supertrait bounds normalized - e.g., if we have a type 'struct Foo<T: Copy>', the
// ParamEnv will contain 'T: Copy' and 'T: Clone', since 'Copy: Clone'. When we construct our
// own ParamEnv, we need to do this ourselves, through traits::elaborate_predicates, or else
// SelectionContext will choke on the missing predicates. However, this should never show up in
// the final synthesized generics: we don't want our generated docs page to contain something
// like 'T: Copy + Clone', as that's redundant. Therefore, we keep track of a separate
// 'user_env', which only holds the predicates that will actually be displayed to the user.
/// The core logic responsible for computing the bounds for our synthesized impl.
///
/// To calculate the bounds, we call `SelectionContext.select` in a loop. Like
/// `FulfillmentContext`, we recursively select the nested obligations of predicates we
/// encounter. However, whenever we encounter an `UnimplementedError` involving a type
/// parameter, we add it to our `ParamEnv`. Since our goal is to determine when a particular
/// type implements an auto trait, Unimplemented errors tell us what conditions need to be met.
///
/// This method ends up working somewhat similarly to `FulfillmentContext`, but with a few key
/// differences. `FulfillmentContext` works under the assumption that it's dealing with concrete
/// user code. According, it considers all possible ways that a `Predicate` could be met, which
/// isn't always what we want for a synthesized impl. For example, given the predicate `T:
/// Iterator`, `FulfillmentContext` can end up reporting an Unimplemented error for `T:
/// IntoIterator` -- since there's an implementation of `Iterator` where `T: IntoIterator`,
/// `FulfillmentContext` will drive `SelectionContext` to consider that impl before giving up.
/// If we were to rely on `FulfillmentContext`s decision, we might end up synthesizing an impl
/// like this:
///
/// impl<T> Send for Foo<T> where T: IntoIterator
///
/// While it might be technically true that Foo implements Send where `T: IntoIterator`,
/// the bound is overly restrictive - it's really only necessary that `T: Iterator`.
///
/// For this reason, `evaluate_predicates` handles predicates with type variables specially.
/// When we encounter an `Unimplemented` error for a bound such as `T: Iterator`, we immediately
/// add it to our `ParamEnv`, and add it to our stack for recursive evaluation. When we later
/// select it, we'll pick up any nested bounds, without ever inferring that `T: IntoIterator`
/// needs to hold.
///
/// One additional consideration is supertrait bounds. Normally, a `ParamEnv` is only ever
/// constructed once for a given type. As part of the construction process, the `ParamEnv` will
/// have any supertrait bounds normalized -- e.g., if we have a type `struct Foo<T: Copy>`, the
/// `ParamEnv` will contain `T: Copy` and `T: Clone`, since `Copy: Clone`. When we construct our
/// own `ParamEnv`, we need to do this ourselves, through `traits::elaborate_predicates`, or
/// else `SelectionContext` will choke on the missing predicates. However, this should never
/// show up in the final synthesized generics: we don't want our generated docs page to contain
/// something like `T: Copy + Clone`, as that's redundant. Therefore, we keep track of a
/// separate `user_env`, which only holds the predicates that will actually be displayed to the
/// user.
fn evaluate_predicates(
&self,
infcx: &InferCtxt<'_, 'tcx>,
@ -307,7 +309,7 @@ impl AutoTraitFinder<'tcx> {
continue;
}
// Call infcx.resolve_vars_if_possible to see if we can
// Call `infcx.resolve_vars_if_possible` to see if we can
// get rid of any inference variables.
let obligation = infcx.resolve_vars_if_possible(
&Obligation::new(dummy_cause.clone(), new_env, pred)
@ -316,14 +318,14 @@ impl AutoTraitFinder<'tcx> {
match &result {
&Ok(Some(ref vtable)) => {
// If we see an explicit negative impl (e.g., 'impl !Send for MyStruct'),
// If we see an explicit negative impl (e.g., `impl !Send for MyStruct`),
// we immediately bail out, since it's impossible for us to continue.
match vtable {
Vtable::VtableImpl(VtableImplData { impl_def_id, .. }) => {
// Blame tidy for the weird bracket placement
// Blame 'tidy' for the weird bracket placement.
if infcx.tcx.impl_polarity(*impl_def_id) == ty::ImplPolarity::Negative
{
debug!("evaluate_nested_obligations: Found explicit negative impl\
debug!("evaluate_nested_obligations: found explicit negative impl\
{:?}, bailing out", impl_def_id);
return None;
}
@ -356,7 +358,7 @@ impl AutoTraitFinder<'tcx> {
predicates.push_back(pred);
} else {
debug!(
"evaluate_nested_obligations: Unimplemented found, bailing: \
"evaluate_nested_obligations: `Unimplemented` found, bailing: \
{:?} {:?} {:?}",
ty,
pred,
@ -392,29 +394,29 @@ impl AutoTraitFinder<'tcx> {
return Some((new_env, final_user_env));
}
// This method is designed to work around the following issue:
// When we compute auto trait bounds, we repeatedly call SelectionContext.select,
// progressively building a ParamEnv based on the results we get.
// However, our usage of SelectionContext differs from its normal use within the compiler,
// in that we capture and re-reprocess predicates from Unimplemented errors.
//
// This can lead to a corner case when dealing with region parameters.
// During our selection loop in evaluate_predicates, we might end up with
// two trait predicates that differ only in their region parameters:
// one containing a HRTB lifetime parameter, and one containing a 'normal'
// lifetime parameter. For example:
//
// T as MyTrait<'a>
// T as MyTrait<'static>
//
// If we put both of these predicates in our computed ParamEnv, we'll
// confuse SelectionContext, since it will (correctly) view both as being applicable.
//
// To solve this, we pick the 'more strict' lifetime bound - i.e., the HRTB
// Our end goal is to generate a user-visible description of the conditions
// under which a type implements an auto trait. A trait predicate involving
// a HRTB means that the type needs to work with any choice of lifetime,
// not just one specific lifetime (e.g., 'static).
/// This method is designed to work around the following issue:
/// When we compute auto trait bounds, we repeatedly call `SelectionContext.select`,
/// progressively building a `ParamEnv` based on the results we get.
/// However, our usage of `SelectionContext` differs from its normal use within the compiler,
/// in that we capture and re-reprocess predicates from `Unimplemented` errors.
///
/// This can lead to a corner case when dealing with region parameters.
/// During our selection loop in `evaluate_predicates`, we might end up with
/// two trait predicates that differ only in their region parameters:
/// one containing a HRTB lifetime parameter, and one containing a 'normal'
/// lifetime parameter. For example:
///
/// T as MyTrait<'a>
/// T as MyTrait<'static>
///
/// If we put both of these predicates in our computed `ParamEnv`, we'll
/// confuse `SelectionContext`, since it will (correctly) view both as being applicable.
///
/// To solve this, we pick the 'more strict' lifetime bound -- i.e., the HRTB
/// Our end goal is to generate a user-visible description of the conditions
/// under which a type implements an auto trait. A trait predicate involving
/// a HRTB means that the type needs to work with any choice of lifetime,
/// not just one specific lifetime (e.g., `'static`).
fn add_user_pred<'c>(
&self,
user_computed_preds: &mut FxHashSet<ty::Predicate<'c>>,
@ -430,7 +432,7 @@ impl AutoTraitFinder<'tcx> {
if !new_substs.types().eq(old_substs.types()) {
// We can't compare lifetimes if the types are different,
// so skip checking old_pred
// so skip checking `old_pred`.
return true;
}
@ -438,8 +440,8 @@ impl AutoTraitFinder<'tcx> {
new_substs.regions().zip(old_substs.regions())
{
match (new_region, old_region) {
// If both predicates have an 'ReLateBound' (a HRTB) in the
// same spot, we do nothing
// If both predicates have an `ReLateBound` (a HRTB) in the
// same spot, we do nothing.
(
ty::RegionKind::ReLateBound(_, _),
ty::RegionKind::ReLateBound(_, _),
@ -463,13 +465,13 @@ impl AutoTraitFinder<'tcx> {
// varaible).
//
// In both cases, we want to remove the old predicate,
// from user_computed_preds, and replace it with the new
// from `user_computed_preds`, and replace it with the new
// one. Having both the old and the new
// predicate in a ParamEnv would confuse SelectionContext
// predicate in a `ParamEnv` would confuse `SelectionContext`.
//
// We're currently in the predicate passed to 'retain',
// so we return 'false' to remove the old predicate from
// user_computed_preds
// so we return `false` to remove the old predicate from
// `user_computed_preds`.
return false;
}
(_, ty::RegionKind::ReLateBound(_, _)) |
@ -486,8 +488,8 @@ impl AutoTraitFinder<'tcx> {
// predicate has some other type of region.
//
// We want to leave the old
// predicate in user_computed_preds, and skip adding
// new_pred to user_computed_params.
// predicate in `user_computed_preds`, and skip adding
// new_pred to `user_computed_params`.
should_add_new = false
},
_ => {}
@ -505,8 +507,8 @@ impl AutoTraitFinder<'tcx> {
}
}
// This is very similar to handle_lifetimes. However, instead of matching ty::Region's
// to each other, we match ty::RegionVid's to ty::Region's
/// This is very similar to `handle_lifetimes`. However, instead of matching `ty::Region`s
/// to each other, we match `ty::RegionVid`s to `ty::Region`s.
fn map_vid_to_region<'cx>(
&self,
regions: &RegionConstraintData<'cx>,
@ -573,7 +575,7 @@ impl AutoTraitFinder<'tcx> {
finished_map.insert(v1, r1);
}
(&RegionTarget::Region(_), &RegionTarget::RegionVid(_)) => {
// Do nothing - we don't care about regions that are smaller than vids
// Do nothing; we don't care about regions that are smaller than vids.
}
(&RegionTarget::RegionVid(_), &RegionTarget::RegionVid(_)) => {
if let Entry::Occupied(v) = vid_map.entry(*smaller) {

35
src/librustc/traits/mod.rs
View file

@ -191,23 +191,23 @@ pub enum ObligationCauseCode<'tcx> {
/// Obligation incurred due to a coercion.
Coercion { source: Ty<'tcx>, target: Ty<'tcx> },
// Various cases where expressions must be sized/copy/etc:
/// L = X implies that L is Sized
/// Various cases where expressions must be `Sized` / `Copy` / etc.
/// `L = X` implies that `L` is `Sized`.
AssignmentLhsSized,
/// (x1, .., xn) must be Sized
/// `(x1, .., xn)` must be `Sized`.
TupleInitializerSized,
/// S { ... } must be Sized
/// `S { ... }` must be `Sized`.
StructInitializerSized,
/// Type of each variable must be Sized
/// Type of each variable must be `Sized`.
VariableType(hir::HirId),
/// Argument type must be Sized
/// Argument type must be `Sized`.
SizedArgumentType,
/// Return type must be Sized
/// Return type must be `Sized`.
SizedReturnType,
/// Yield type must be Sized
/// Yield type must be `Sized`.
SizedYieldType,
/// [T,..n] --> T must be Copy. If `true`, suggest `const_in_array_repeat_expressions` feature
/// flag.
/// `[T, ..n]` implies that `T` must be `Copy`.
/// If `true`, suggest `const_in_array_repeat_expressions` feature flag.
RepeatVec(bool),
/// Types of fields (other than the last, except for packed structs) in a struct must be sized.
@ -216,7 +216,7 @@ pub enum ObligationCauseCode<'tcx> {
/// Constant expressions must be sized.
ConstSized,
/// Static items must have `Sync` type
/// `static` items must have `Sync` type.
SharedStatic,
BuiltinDerivedObligation(DerivedObligationCause<'tcx>),
@ -602,7 +602,7 @@ pub enum Vtable<'tcx, N> {
/// the impl's type parameters.
///
/// The type parameter `N` indicates the type used for "nested
/// obligations" that are required by the impl. During type check, this
/// obligations" that are required by the impl. During type-check, this
/// is `Obligation`, as one might expect. During codegen, however, this
/// is `()`, because codegen only requires a shallow resolution of an
/// impl, and nested obligations are satisfied later.
@ -1046,8 +1046,7 @@ fn vtable_methods<'tcx>(
return None;
}
// the method may have some early-bound lifetimes, add
// regions for those
// The method may have some early-bound lifetimes; add regions for those.
let substs = trait_ref.map_bound(|trait_ref|
InternalSubsts::for_item(tcx, def_id, |param, _|
match param.kind {
@ -1060,15 +1059,15 @@ fn vtable_methods<'tcx>(
)
);
// the trait type may have higher-ranked lifetimes in it;
// so erase them if they appear, so that we get the type
// at some particular call site
// The trait type may have higher-ranked lifetimes in it;
// erase them if they appear, so that we get the type
// at some particular call site.
let substs = tcx.normalize_erasing_late_bound_regions(
ty::ParamEnv::reveal_all(),
&substs
);
// It's possible that the method relies on where clauses that
// It's possible that the method relies on where-clauses that
// do not hold for this particular set of type parameters.
// Note that this method could then never be called, so we
// do not want to try and codegen it, in that case (see #23435).

256
src/librustc/traits/select.rs
View file

@ -157,7 +157,7 @@ impl IntercrateAmbiguityCause {
struct TraitObligationStack<'prev, 'tcx> {
obligation: &'prev TraitObligation<'tcx>,
/// Trait ref from `obligation` but "freshened" with the
/// The trait ref from `obligation` but "freshened" with the
/// selection-context's freshener. Used to check for recursion.
fresh_trait_ref: ty::PolyTraitRef<'tcx>,
@ -193,11 +193,11 @@ struct TraitObligationStack<'prev, 'tcx> {
previous: TraitObligationStackList<'prev, 'tcx>,
/// Number of parent frames plus one -- so the topmost frame has depth 1.
/// The number of parent frames plus one (thus, the topmost frame has depth 1).
depth: usize,
/// Depth-first number of this node in the search graph -- a
/// pre-order index. Basically a freshly incremented counter.
/// The depth-first number of this node in the search graph -- a
/// pre-order index. Basically, a freshly incremented counter.
dfn: usize,
}
@ -239,9 +239,9 @@ pub struct SelectionCache<'tcx> {
/// }
/// fn foo<T: AsDebug>(t: T) { println!("{:?}", <T as AsDebug>::debug(t)); }
///
/// we can't just use the impl to resolve the <T as AsDebug> obligation
/// - a type from another crate (that doesn't implement fmt::Debug) could
/// implement AsDebug.
/// we can't just use the impl to resolve the `<T as AsDebug>` obligation
/// -- a type from another crate (that doesn't implement `fmt::Debug`) could
/// implement `AsDebug`.
///
/// Because where-clauses match the type exactly, multiple clauses can
/// only match if there are unresolved variables, and we can mostly just
@ -266,10 +266,10 @@ pub struct SelectionCache<'tcx> {
/// }
/// fn main() { foo(false); }
///
/// Here the obligation <T as Foo<$0>> can be matched by both the blanket
/// impl and the where-clause. We select the where-clause and unify $0=bool,
/// Here the obligation `<T as Foo<$0>>` can be matched by both the blanket
/// impl and the where-clause. We select the where-clause and unify `$0=bool`,
/// so the program prints "false". However, if the where-clause is omitted,
/// the blanket impl is selected, we unify $0=(), and the program prints
/// the blanket impl is selected, we unify `$0=()`, and the program prints
/// "()".
///
/// Exactly the same issues apply to projection and object candidates, except
@ -282,8 +282,8 @@ pub struct SelectionCache<'tcx> {
/// parameter environment.
#[derive(PartialEq, Eq, Debug, Clone, TypeFoldable)]
enum SelectionCandidate<'tcx> {
/// If has_nested is false, there are no *further* obligations
BuiltinCandidate {
/// `false` if there are no *further* obligations.
has_nested: bool,
},
ParamCandidate(ty::PolyTraitRef<'tcx>),
@ -339,11 +339,11 @@ impl<'a, 'tcx> ty::Lift<'tcx> for SelectionCandidate<'a> {
}
struct SelectionCandidateSet<'tcx> {
// a list of candidates that definitely apply to the current
// A list of candidates that definitely apply to the current
// obligation (meaning: types unify).
vec: Vec<SelectionCandidate<'tcx>>,
// if this is true, then there were candidates that might or might
// If `true`, then there were candidates that might or might
// not have applied, but we couldn't tell. This occurs when some
// of the input types are type variables, in which case there are
// various "builtin" rules that might or might not trigger.
@ -358,7 +358,7 @@ struct EvaluatedCandidate<'tcx> {
/// When does the builtin impl for `T: Trait` apply?
enum BuiltinImplConditions<'tcx> {
/// The impl is conditional on T1,T2,.. : Trait
/// The impl is conditional on `T1, T2, ...: Trait`.
Where(ty::Binder<Vec<Ty<'tcx>>>),
/// There is no built-in impl. There may be some other
/// candidate (a where-clause or user-defined impl).
@ -381,15 +381,15 @@ enum BuiltinImplConditions<'tcx> {
/// the categories it's easy to see that the unions are correct.
#[derive(Copy, Clone, Debug, PartialOrd, Ord, PartialEq, Eq, HashStable)]
pub enum EvaluationResult {
/// Evaluation successful
/// Evaluation successful.
EvaluatedToOk,
/// Evaluation successful, but there were unevaluated region obligations
/// Evaluation successful, but there were unevaluated region obligations.
EvaluatedToOkModuloRegions,
/// Evaluation is known to be ambiguous - it *might* hold for some
/// Evaluation is known to be ambiguous -- it *might* hold for some
/// assignment of inference variables, but it might not.
///
/// While this has the same meaning as `EvaluatedToUnknown` - we can't
/// know whether this obligation holds or not - it is the result we
/// While this has the same meaning as `EvaluatedToUnknown` -- we can't
/// know whether this obligation holds or not -- it is the result we
/// would get with an empty stack, and therefore is cacheable.
EvaluatedToAmbig,
/// Evaluation failed because of recursion involving inference
@ -404,10 +404,10 @@ pub enum EvaluationResult {
/// We know this branch can't be a part of a minimal proof-tree for
/// the "root" of our cycle, because then we could cut out the recursion
/// and maintain a valid proof tree. However, this does not mean
/// that all the obligations on this branch do not hold - it's possible
/// that all the obligations on this branch do not hold -- it's possible
/// that we entered this branch "speculatively", and that there
/// might be some other way to prove this obligation that does not
/// go through this cycle - so we can't cache this as a failure.
/// go through this cycle -- so we can't cache this as a failure.
///
/// For example, suppose we have this:
///
@ -723,10 +723,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
debug!("evaluate_predicate_recursively(previous_stack={:?}, obligation={:?})",
previous_stack.head(), obligation);
// Previous_stack stores a TraitObligatiom, while 'obligation' is
// a PredicateObligation. These are distinct types, so we can't
// use any Option combinator method that would force them to be
// the same
// `previous_stack` stores a `TraitObligatiom`, while `obligation` is
// a `PredicateObligation`. These are distinct types, so we can't
// use any `Option` combinator method that would force them to be
// the same.
match previous_stack.head() {
Some(h) => self.check_recursion_limit(&obligation, h.obligation)?,
None => self.check_recursion_limit(&obligation, &obligation)?
@ -740,7 +740,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
ty::Predicate::Subtype(ref p) => {
// does this code ever run?
// Does this code ever run?
match self.infcx
.subtype_predicate(&obligation.cause, obligation.param_env, p)
{
@ -768,8 +768,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
},
ty::Predicate::TypeOutlives(..) | ty::Predicate::RegionOutlives(..) => {
// we do not consider region relationships when
// evaluating trait matches
// We do not consider region relationships when evaluating trait matches.
Ok(EvaluatedToOkModuloRegions)
}
@ -953,7 +952,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
stack: &TraitObligationStack<'_, 'tcx>,
) -> Option<EvaluationResult> {
if let Some(cycle_depth) = stack.iter()
.skip(1) // skip top-most frame
.skip(1) // Skip top-most frame.
.find(|prev| stack.obligation.param_env == prev.obligation.param_env &&
stack.fresh_trait_ref == prev.fresh_trait_ref)
.map(|stack| stack.depth)
@ -1030,8 +1029,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
.skip_binder()
.input_types()
.any(|ty| ty.is_fresh());
// this check was an imperfect workaround for a bug n the old
// intercrate mode, it should be removed when that goes away.
// This check was an imperfect workaround for a bug in the old
// intercrate mode; it should be removed when that goes away.
if unbound_input_types && self.intercrate == Some(IntercrateMode::Issue43355) {
debug!(
"evaluate_stack({:?}) --> unbound argument, intercrate --> ambiguous",
@ -1083,7 +1082,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
/// For defaulted traits, we use a co-inductive strategy to solve, so
/// that recursion is ok. This routine returns true if the top of the
/// that recursion is ok. This routine returns `true` if the top of the
/// stack (`cycle[0]`):
///
/// - is a defaulted trait,
@ -1107,7 +1106,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
result
}
/// Further evaluate `candidate` to decide whether all type parameters match and whether nested
/// Further evaluates `candidate` to decide whether all type parameters match and whether nested
/// obligations are met. Returns whether `candidate` remains viable after this further
/// scrutiny.
fn evaluate_candidate<'o>(
@ -1199,26 +1198,26 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
.insert(trait_ref, WithDepNode::new(dep_node, result));
}
// For various reasons, it's possible for a subobligation
// to have a *lower* recursion_depth than the obligation used to create it.
// Projection sub-obligations may be returned from the projection cache,
// which results in obligations with an 'old' recursion_depth.
// Additionally, methods like ty::wf::obligations and
// InferCtxt.subtype_predicate produce subobligations without
// taking in a 'parent' depth, causing the generated subobligations
// to have a recursion_depth of 0
//
// To ensure that obligation_depth never decreasees, we force all subobligations
// to have at least the depth of the original obligation.
/// For various reasons, it's possible for a subobligation
/// to have a *lower* recursion_depth than the obligation used to create it.
/// Projection sub-obligations may be returned from the projection cache,
/// which results in obligations with an 'old' `recursion_depth`.
/// Additionally, methods like `ty::wf::obligations` and
/// `InferCtxt.subtype_predicate` produce subobligations without
/// taking in a 'parent' depth, causing the generated subobligations
/// to have a `recursion_depth` of `0`.
///
/// To ensure that obligation_depth never decreasees, we force all subobligations
/// to have at least the depth of the original obligation.
fn add_depth<T: 'cx, I: Iterator<Item = &'cx mut Obligation<'tcx, T>>>(&self, it: I,
min_depth: usize) {
it.for_each(|o| o.recursion_depth = cmp::max(min_depth, o.recursion_depth) + 1);
}
// Check that the recursion limit has not been exceeded.
//
// The weird return type of this function allows it to be used with the 'try' (?)
// operator within certain functions
/// Checks that the recursion limit has not been exceeded.
///
/// The weird return type of this function allows it to be used with the `try` (`?`)
/// operator within certain functions.
fn check_recursion_limit<T: Display + TypeFoldable<'tcx>, V: Display + TypeFoldable<'tcx>>(
&self,
obligation: &Obligation<'tcx, T>,
@ -1256,7 +1255,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// not update) the cache.
self.check_recursion_limit(&stack.obligation, &stack.obligation)?;
// Check the cache. Note that we freshen the trait-ref
// separately rather than using `stack.fresh_trait_ref` --
// this is because we want the unbound variables to be
@ -1436,10 +1434,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// candidate set is *individually* applicable. Now we have to
// figure out if they contain mutual incompatibilities. This
// frequently arises if we have an unconstrained input type --
// for example, we are looking for $0:Eq where $0 is some
// for example, we are looking for `$0: Eq` where `$0` is some
// unconstrained type variable. In that case, we'll get a
// candidate which assumes $0 == int, one that assumes $0 ==
// usize, etc. This spells an ambiguity.
// candidate which assumes $0 == int, one that assumes `$0 ==
// usize`, etc. This spells an ambiguity.
// If there is more than one candidate, first winnow them down
// by considering extra conditions (nested obligations and so
@ -1453,8 +1451,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// and we were to see some code `foo.push_clone()` where `boo`
// is a `Vec<Bar>` and `Bar` does not implement `Clone`. If
// we were to winnow, we'd wind up with zero candidates.
// Instead, we select the right impl now but report `Bar does
// not implement Clone`.
// Instead, we select the right impl now but report "`Bar` does
// not implement `Clone`".
if candidates.len() == 1 {
return self.filter_negative_and_reservation_impls(candidates.pop().unwrap());
}
@ -1586,7 +1584,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// avoid us having to fear that coherence results "pollute"
// the master cache. Since coherence executes pretty quickly,
// it's not worth going to more trouble to increase the
// hit-rate I don't think.
// hit-rate, I don't think.
if self.intercrate.is_some() {
return false;
}
@ -1617,13 +1615,13 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
/// Determines whether can we safely cache the result
/// of selecting an obligation. This is almost always 'true',
/// except when dealing with certain ParamCandidates.
/// of selecting an obligation. This is almost always `true`,
/// except when dealing with certain `ParamCandidate`s.
///
/// Ordinarily, a ParamCandidate will contain no inference variables,
/// since it was usually produced directly from a DefId. However,
/// Ordinarily, a `ParamCandidate` will contain no inference variables,
/// since it was usually produced directly from a `DefId`. However,
/// certain cases (currently only librustdoc's blanket impl finder),
/// a ParamEnv may be explicitly constructed with inference types.
/// a `ParamEnv` may be explicitly constructed with inference types.
/// When this is the case, we do *not* want to cache the resulting selection
/// candidate. This is due to the fact that it might not always be possible
/// to equate the obligation's trait ref and the candidate's trait ref,
@ -1631,7 +1629,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
///
/// Because of this, we always want to re-run the full selection
/// process for our obligation the next time we see it, since
/// we might end up picking a different SelectionCandidate (or none at all)
/// we might end up picking a different `SelectionCandidate` (or none at all).
fn can_cache_candidate(&self,
result: &SelectionResult<'tcx, SelectionCandidate<'tcx>>
) -> bool {
@ -1662,15 +1660,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
if self.can_use_global_caches(param_env) {
if let Err(Overflow) = candidate {
// Don't cache overflow globally; we only produce this
// in certain modes.
// Don't cache overflow globally; we only produce this in certain modes.
} else if !trait_ref.has_local_value() {
if !candidate.has_local_value() {
debug!(
"insert_candidate_cache(trait_ref={:?}, candidate={:?}) global",
trait_ref, candidate,
);
// This may overwrite the cache with the same value
// This may overwrite the cache with the same value.
tcx.selection_cache
.hashmap
.borrow_mut()
@ -1755,7 +1752,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
} else {
if lang_items.clone_trait() == Some(def_id) {
// Same builtin conditions as `Copy`, i.e., every type which has builtin support
// for `Copy` also has builtin support for `Clone`, + tuples and arrays of `Clone`
// for `Copy` also has builtin support for `Clone`, and tuples/arrays of `Clone`
// types have builtin support for `Clone`.
let clone_conditions = self.copy_clone_conditions(obligation);
self.assemble_builtin_bound_candidates(clone_conditions, &mut candidates)?;
@ -1786,7 +1783,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
) {
debug!("assemble_candidates_for_projected_tys({:?})", obligation);
// before we go into the whole placeholder thing, just
// Before we go into the whole placeholder thing, just
// quickly check if the self-type is a projection at all.
match obligation.predicate.skip_binder().trait_ref.self_ty().kind {
ty::Projection(_) | ty::Opaque(..) => {}
@ -1907,10 +1904,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
self.infcx.leak_check(false, placeholder_map, snapshot).is_ok()
}
/// Given an obligation like `<SomeTrait for T>`, search the obligations that the caller
/// Given an obligation like `<SomeTrait for T>`, searches the obligations that the caller
/// supplied to find out whether it is listed among them.
///
/// Never affects inference environment.
/// Never affects the inference environment.
fn assemble_candidates_from_caller_bounds<'o>(
&mut self,
stack: &TraitObligationStack<'o, 'tcx>,
@ -2052,7 +2049,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
Ok(())
}
/// Implement one of the `Fn()` family for a fn pointer.
/// Implements one of the `Fn()` family for a fn pointer.
fn assemble_fn_pointer_candidates(
&mut self,
obligation: &TraitObligation<'tcx>,
@ -2067,14 +2064,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
return Ok(());
}
// Okay to skip binder because what we are inspecting doesn't involve bound regions
// Okay to skip binder because what we are inspecting doesn't involve bound regions.
let self_ty = *obligation.self_ty().skip_binder();
match self_ty.kind {
ty::Infer(ty::TyVar(_)) => {
debug!("assemble_fn_pointer_candidates: ambiguous self-type");
candidates.ambiguous = true; // could wind up being a fn() type
candidates.ambiguous = true; // Could wind up being a fn() type.
}
// provide an impl, but only for suitable `fn` pointers
// Provide an impl, but only for suitable `fn` pointers.
ty::FnDef(..) | ty::FnPtr(_) => {
if let ty::FnSig {
unsafety: hir::Unsafety::Normal,
@ -2092,7 +2089,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
Ok(())
}
/// Search for impls that might apply to `obligation`.
/// Searches for impls that might apply to `obligation`.
fn assemble_candidates_from_impls(
&mut self,
obligation: &TraitObligation<'tcx>,
@ -2160,7 +2157,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// this path.
}
ty::Infer(ty::TyVar(_)) => {
// the auto impl might apply, we don't know
// The auto impl might apply; we don't know.
candidates.ambiguous = true;
}
ty::Generator(_, _, movability)
@ -2188,7 +2185,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
Ok(())
}
/// Search for impls that might apply to `obligation`.
/// Searches for impls that might apply to `obligation`.
fn assemble_candidates_from_object_ty(
&mut self,
obligation: &TraitObligation<'tcx>,
@ -2226,7 +2223,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
return;
}
} else {
// Only auto-trait bounds exist.
// Only auto trait bounds exist.
return;
}
}
@ -2267,7 +2264,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
})
}
/// Search for unsizing that might apply to `obligation`.
/// Searches for unsizing that might apply to `obligation`.
fn assemble_candidates_for_unsizing(
&mut self,
obligation: &TraitObligation<'tcx>,
@ -2311,7 +2308,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
(&ty::Dynamic(ref data_a, ..), &ty::Dynamic(ref data_b, ..)) => {
// Upcasts permit two things:
//
// 1. Dropping builtin bounds, e.g., `Foo+Send` to `Foo`
// 1. Dropping auto traits, e.g., `Foo + Send` to `Foo`
// 2. Tightening the region bound, e.g., `Foo + 'a` to `Foo + 'b` if `'a: 'b`
//
// Note that neither of these changes requires any
@ -2326,11 +2323,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
.all(|b| data_a.auto_traits().any(|a| a == b))
}
// T -> Trait.
// `T` -> `Trait`
(_, &ty::Dynamic(..)) => true,
// Ambiguous handling is below T -> Trait, because inference
// variables can still implement Unsize<Trait> and nested
// Ambiguous handling is below `T` -> `Trait`, because inference
// variables can still implement `Unsize<Trait>` and nested
// obligations will have the final say (likely deferred).
(&ty::Infer(ty::TyVar(_)), _) | (_, &ty::Infer(ty::TyVar(_))) => {
debug!("assemble_candidates_for_unsizing: ambiguous");
@ -2338,15 +2335,15 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
false
}
// [T; n] -> [T].
// `[T; n]` -> `[T]`
(&ty::Array(..), &ty::Slice(_)) => true,
// Struct<T> -> Struct<U>.
// `Struct<T>` -> `Struct<U>`
(&ty::Adt(def_id_a, _), &ty::Adt(def_id_b, _)) if def_id_a.is_struct() => {
def_id_a == def_id_b
}
// (.., T) -> (.., U).
// `(.., T)` -> `(.., U)`
(&ty::Tuple(tys_a), &ty::Tuple(tys_b)) => tys_a.len() == tys_b.len(),
_ => false,
@ -2404,7 +2401,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
|cand: &ty::PolyTraitRef<'_>| cand.is_global() && !cand.has_late_bound_regions();
match other.candidate {
// Prefer BuiltinCandidate { has_nested: false } to anything else.
// Prefer `BuiltinCandidate { has_nested: false }` to anything else.
// This is a fix for #53123 and prevents winnowing from accidentally extending the
// lifetime of a variable.
BuiltinCandidate { has_nested: false } => true,
@ -2415,7 +2412,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
when there are other valid candidates"
);
}
// Prefer BuiltinCandidate { has_nested: false } to anything else.
// Prefer `BuiltinCandidate { has_nested: false }` to anything else.
// This is a fix for #53123 and prevents winnowing from accidentally extending the
// lifetime of a variable.
BuiltinCandidate { has_nested: false } => false,
@ -2446,7 +2443,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
when there are other valid candidates"
);
}
// Prefer BuiltinCandidate { has_nested: false } to anything else.
// Prefer `BuiltinCandidate { has_nested: false }` to anything else.
// This is a fix for #53123 and prevents winnowing from accidentally extending the
// lifetime of a variable.
BuiltinCandidate { has_nested: false } => false,
@ -2468,7 +2465,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
ImplCandidate(other_def) => {
// See if we can toss out `victim` based on specialization.
// This requires us to know *for sure* that the `other` impl applies
// i.e., EvaluatedToOk:
// i.e., `EvaluatedToOk`.
if other.evaluation.must_apply_modulo_regions() {
match victim.candidate {
ImplCandidate(victim_def) => {
@ -2496,7 +2493,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
match victim.candidate {
ParamCandidate(ref cand) => {
// Prefer these to a global where-clause bound
// (see issue #50825)
// (see issue #50825).
is_global(cand) && other.evaluation.must_apply_modulo_regions()
}
_ => false,
@ -2754,7 +2751,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
types.skip_binder().to_vec()
}
// for `PhantomData<T>`, we pass `T`
// For `PhantomData<T>`, we pass `T`.
ty::Adt(def, substs) if def.is_phantom_data() => substs.types().collect(),
ty::Adt(def, substs) => def.all_fields().map(|f| f.ty(self.tcx(), substs)).collect(),
@ -2894,11 +2891,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
BuiltinObjectCandidate => {
// This indicates something like `(Trait+Send) :
// Send`. In this case, we know that this holds
// because that's what the object type is telling us,
// and there's really no additional obligations to
// prove and no types in particular to unify etc.
// This indicates something like `Trait + Send: Send`. In this case, we know that
// this holds because that's what the object type is telling us, and there's really
// no additional obligations to prove and no types in particular to unify, etc.
Ok(VtableParam(Vec::new()))
}
@ -3152,7 +3147,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// We want to find the first supertrait in the list of
// supertraits that we can unify with, and do that
// unification. We know that there is exactly one in the list
// where we can unify because otherwise select would have
// where we can unify, because otherwise select would have
// reported an ambiguity. (When we do find a match, also
// record it for later.)
let nonmatching = util::supertraits(tcx, poly_trait_ref).take_while(
@ -3166,7 +3161,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
},
);
// Additionally, for each of the nonmatching predicates that
// Additionally, for each of the non-matching predicates that
// we pass over, we sum up the set of number of vtable
// entries, so that we can compute the offset for the selected
// trait.
@ -3354,7 +3349,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
trait_ref,
)?);
// FIXME: chalk
// FIXME: Chalk
if !self.tcx().sess.opts.debugging_opts.chalk {
obligations.push(Obligation::new(
@ -3421,7 +3416,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
) -> Result<VtableBuiltinData<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
let tcx = self.tcx();
// assemble_candidates_for_unsizing should ensure there are no late bound
// `assemble_candidates_for_unsizing` should ensure there are no late-bound
// regions here. See the comment there for more details.
let source = self.infcx
.shallow_resolve(obligation.self_ty().no_bound_vars().unwrap());
@ -3442,7 +3437,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
match (&source.kind, &target.kind) {
// Trait+Kx+'a -> Trait+Ky+'b (upcasts).
(&ty::Dynamic(ref data_a, r_a), &ty::Dynamic(ref data_b, r_b)) => {
// See assemble_candidates_for_unsizing for more info.
// See `assemble_candidates_for_unsizing` for more info.
let existential_predicates = data_a.map_bound(|data_a| {
let iter =
data_a.principal().map(|x| ty::ExistentialPredicate::Trait(x))
@ -3463,20 +3458,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// Require that the traits involved in this upcast are **equal**;
// only the **lifetime bound** is changed.
//
// FIXME: This condition is arguably too strong -- it
// would suffice for the source trait to be a
// *subtype* of the target trait. In particular
// changing from something like `for<'a, 'b> Foo<'a,
// 'b>` to `for<'a> Foo<'a, 'a>` should be
// FIXME: This condition is arguably too strong -- it would
// suffice for the source trait to be a *subtype* of the target
// trait. In particular, changing from something like
// `for<'a, 'b> Foo<'a, 'b>` to `for<'a> Foo<'a, 'a>` should be
// permitted. And, indeed, in the in commit
// 904a0bde93f0348f69914ee90b1f8b6e4e0d7cbc, this
// condition was loosened. However, when the leak check was added
// back, using subtype here actually guies the coercion code in
// such a way that it accepts `old-lub-glb-object.rs`. This is probably
// a good thing, but I've modified this to `.eq` because I want
// to continue rejecting that test (as we have done for quite some time)
// before we are firmly comfortable with what our behavior
// should be there. -nikomatsakis
// condition was loosened. However, when the leak check was
// added back, using subtype here actually guides the coercion
// code in such a way that it accepts `old-lub-glb-object.rs`.
// This is probably a good thing, but I've modified this to `.eq`
// because I want to continue rejecting that test (as we have
// done for quite some time) before we are firmly comfortable
// with what our behavior should be there. -nikomatsakis
let InferOk { obligations, .. } = self.infcx
.at(&obligation.cause, obligation.param_env)
.eq(target, source_trait) // FIXME -- see below
@ -3498,7 +3492,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
));
}
// T -> Trait.
// `T` -> `Trait`
(_, &ty::Dynamic(ref data, r)) => {
let mut object_dids = data.auto_traits()
.chain(data.principal_def_id());
@ -3522,24 +3516,26 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
};
// Create obligations:
// - Casting T to Trait
// - Casting `T` to `Trait`
// - For all the various builtin bounds attached to the object cast. (In other
// words, if the object type is Foo+Send, this would create an obligation for the
// Send check.)
// words, if the object type is `Foo + Send`, this would create an obligation for
// the `Send` check.)
// - Projection predicates
nested.extend(
data.iter()
.map(|d| predicate_to_obligation(d.with_self_ty(tcx, source))),
.map(|predicate|
predicate_to_obligation(predicate.with_self_ty(tcx, source))
),
);
// We can only make objects from sized types.
let tr = ty::TraitRef {
def_id: tcx.require_lang_item(lang_items::SizedTraitLangItem, None),
substs: tcx.mk_substs_trait(source, &[]),
};
let tr = ty::TraitRef::new(
tcx.require_lang_item(lang_items::SizedTraitLangItem, None),
tcx.mk_substs_trait(source, &[]),
);
nested.push(predicate_to_obligation(tr.to_predicate()));
// If the type is `Foo+'a`, ensures that the type
// If the type is `Foo + 'a`, ensure that the type
// being cast to `Foo + 'a` outlives `'a`:
let outlives = ty::OutlivesPredicate(source, r);
nested.push(predicate_to_obligation(
@ -3547,7 +3543,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
));
}
// [T; n] -> [T].
// `[T; n]` -> `[T]`
(&ty::Array(a, _), &ty::Slice(b)) => {
let InferOk { obligations, .. } = self.infcx
.at(&obligation.cause, obligation.param_env)
@ -3556,10 +3552,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
nested.extend(obligations);
}
// Struct<T> -> Struct<U>.
// `Struct<T>` -> `Struct<U>`
(&ty::Adt(def, substs_a), &ty::Adt(_, substs_b)) => {
let fields = def.all_fields()
.map(|f| tcx.type_of(f.did))
.map(|field| tcx.type_of(field.did))
.collect::<Vec<_>>();
// The last field of the structure has to exist and contain type parameters.
@ -3598,7 +3594,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
// Extract Field<T> and Field<U> from Struct<T> and Struct<U>.
// Extract `Field<T>` and `Field<U>` from `Struct<T>` and `Struct<U>`.
let inner_source = field.subst(tcx, substs_a);
let inner_target = field.subst(tcx, substs_b);
@ -3618,7 +3614,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
.map_err(|_| Unimplemented)?;
nested.extend(obligations);
// Construct the nested Field<T>: Unsize<Field<U>> predicate.
// Construct the nested `Field<T>: Unsize<Field<U>>` predicate.
nested.push(tcx.predicate_for_trait_def(
obligation.param_env,
obligation.cause.clone(),
@ -3629,7 +3625,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
));
}
// (.., T) -> (.., U).
// `(.., T)` -> `(.., U)`
(&ty::Tuple(tys_a), &ty::Tuple(tys_b)) => {
assert_eq!(tys_a.len(), tys_b.len());
@ -3652,7 +3648,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
.map_err(|_| Unimplemented)?;
nested.extend(obligations);
// Construct the nested T: Unsize<U> predicate.
// Construct the nested `T: Unsize<U>` predicate.
nested.push(tcx.predicate_for_trait_def(
obligation.param_env,
obligation.cause.clone(),
@ -3969,7 +3965,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
//
// This code is hot enough that it's worth avoiding the allocation
// required for the FxHashSet when possible. Special-casing lengths 0,
// 1 and 2 covers roughly 75--80% of the cases.
// 1 and 2 covers roughly 75-80% of the cases.
if predicates.len() <= 1 {
// No possibility of duplicates.
} else if predicates.len() == 2 {

2
src/librustc/traits/util.rs
View file

@ -80,7 +80,7 @@ impl<T: AsRef<ty::Predicate<'tcx>>> Extend<T> for PredicateSet<'tcx> {
///////////////////////////////////////////////////////////////////////////
/// "Elaboration" is the process of identifying all the predicates that
/// are implied by a source predicate. Currently this basically means
/// are implied by a source predicate. Currently, this basically means
/// walking the "supertraits" and other similar assumptions. For example,
/// if we know that `T: Ord`, the elaborator would deduce that `T: PartialOrd`
/// holds as well. Similarly, if we have `trait Foo: 'static`, and we know that

9
src/librustc/ty/error.rs
View file

@ -1,14 +1,15 @@
use crate::hir;
use crate::hir::def_id::DefId;
use crate::ty::{self, BoundRegion, Region, Ty, TyCtxt};
use std::borrow::Cow;
use std::fmt;
use errors::{Applicability, DiagnosticBuilder};
use rustc_target::spec::abi;
use syntax::ast;
use syntax::errors::pluralize;
use errors::{Applicability, DiagnosticBuilder};
use syntax_pos::Span;
use crate::hir;
use std::borrow::Cow;
use std::fmt;
#[derive(Clone, Copy, Debug, PartialEq, Eq, TypeFoldable)]
pub struct ExpectedFound<T> {

6
src/librustc/ty/instance.rs
View file

@ -36,10 +36,10 @@ pub enum InstanceDef<'tcx> {
ReifyShim(DefId),
/// `<fn() as FnTrait>::call_*`
/// `DefId` is `FnTrait::call_*`
/// `DefId` is `FnTrait::call_*`.
FnPtrShim(DefId, Ty<'tcx>),
/// `<Trait as Trait>::fn`
/// `<dyn Trait as Trait>::fn`
Virtual(DefId, usize),
/// `<[mut closure] as FnOnce>::call_once`
@ -115,7 +115,7 @@ impl<'tcx> Instance<'tcx> {
pub fn fn_sig(&self, tcx: TyCtxt<'tcx>) -> ty::PolyFnSig<'tcx> {
let mut fn_sig = self.fn_sig_noadjust(tcx);
if let InstanceDef::VtableShim(..) = self.def {
// Modify fn(self, ...) to fn(self: *mut Self, ...)
// Modify `fn(self, ...)` to `fn(self: *mut Self, ...)`.
fn_sig = fn_sig.map_bound(|mut fn_sig| {
let mut inputs_and_output = fn_sig.inputs_and_output.to_vec();
inputs_and_output[0] = tcx.mk_mut_ptr(inputs_and_output[0]);

4
src/librustc/ty/layout.rs
View file

@ -2103,8 +2103,8 @@ where
ty::RawPtr(ty::TypeAndMut { ty: pointee, .. }) => {
assert!(i < this.fields.count());
// Reuse the fat *T type as its own thin pointer data field.
// This provides information about e.g., DST struct pointees
// Reuse the fat `*T` type as its own thin pointer data field.
// This provides information about, e.g., DST struct pointees
// (which may have no non-DST form), and will work as long
// as the `Abi` or `FieldPlacement` is checked by users.
if i == 0 {

9
src/librustc/ty/mod.rs
View file

@ -1923,17 +1923,17 @@ pub struct FieldDef {
///
/// These are all interned (by `intern_adt_def`) into the `adt_defs` table.
///
/// The initialism *"Adt"* stands for an [*algebraic data type (ADT)*][adt].
/// The initialism *ADT* stands for an [*algebraic data type (ADT)*][adt].
/// This is slightly wrong because `union`s are not ADTs.
/// Moreover, Rust only allows recursive data types through indirection.
///
/// [adt]: https://en.wikipedia.org/wiki/Algebraic_data_type
pub struct AdtDef {
/// `DefId` of the struct, enum or union item.
/// The `DefId` of the struct, enum or union item.
pub did: DefId,
/// Variants of the ADT. If this is a struct or union, then there will be a single variant.
pub variants: IndexVec<self::layout::VariantIdx, VariantDef>,
/// Flags of the ADT (e.g. is this a struct? is this non-exhaustive?)
/// Flags of the ADT (e.g., is this a struct? is this non-exhaustive?).
flags: AdtFlags,
/// Repr options provided by the user.
pub repr: ReprOptions,
@ -1954,7 +1954,7 @@ impl Ord for AdtDef {
}
impl PartialEq for AdtDef {
// AdtDef are always interned and this is part of TyS equality
// `AdtDef`s are always interned, and this is part of `TyS` equality.
#[inline]
fn eq(&self, other: &Self) -> bool { ptr::eq(self, other) }
}
@ -1976,7 +1976,6 @@ impl<'tcx> rustc_serialize::UseSpecializedEncodable for &'tcx AdtDef {
impl<'tcx> rustc_serialize::UseSpecializedDecodable for &'tcx AdtDef {}
impl<'a> HashStable<StableHashingContext<'a>> for AdtDef {
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
thread_local! {

4
src/librustc/ty/relate.rs
View file

@ -281,7 +281,7 @@ impl<'tcx> Relate<'tcx> for ty::TraitRef<'tcx> {
a: &ty::TraitRef<'tcx>,
b: &ty::TraitRef<'tcx>,
) -> RelateResult<'tcx, ty::TraitRef<'tcx>> {
// Different traits cannot be related
// Different traits cannot be related.
if a.def_id != b.def_id {
Err(TypeError::Traits(expected_found(relation, &a.def_id, &b.def_id)))
} else {
@ -297,7 +297,7 @@ impl<'tcx> Relate<'tcx> for ty::ExistentialTraitRef<'tcx> {
a: &ty::ExistentialTraitRef<'tcx>,
b: &ty::ExistentialTraitRef<'tcx>,
) -> RelateResult<'tcx, ty::ExistentialTraitRef<'tcx>> {
// Different traits cannot be related
// Different traits cannot be related.
if a.def_id != b.def_id {
Err(TypeError::Traits(expected_found(relation, &a.def_id, &b.def_id)))
} else {

3
src/librustc/ty/structural_impls.rs
View file

@ -4,12 +4,13 @@
use crate::hir::def::Namespace;
use crate::mir::ProjectionKind;
use crate::mir::interpret;
use crate::ty::{self, Lift, Ty, TyCtxt, InferConst};
use crate::ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
use crate::ty::print::{FmtPrinter, Printer};
use rustc_index::vec::{IndexVec, Idx};
use smallvec::SmallVec;
use crate::mir::interpret;
use std::fmt;
use std::rc::Rc;

79
src/librustc/ty/sty.rs
View file

@ -2,14 +2,14 @@
#![allow(rustc::usage_of_ty_tykind)]
use self::InferTy::*;
use self::TyKind::*;
use crate::hir;
use crate::hir::def_id::DefId;
use crate::infer::canonical::Canonical;
use crate::mir::interpret::ConstValue;
use crate::middle::region;
use polonius_engine::Atom;
use rustc_index::vec::Idx;
use rustc_macros::HashStable;
use crate::ty::subst::{InternalSubsts, Subst, SubstsRef, GenericArg, GenericArgKind};
use crate::ty::{self, AdtDef, Discr, DefIdTree, TypeFlags, Ty, TyCtxt, TypeFoldable};
use crate::ty::{List, TyS, ParamEnvAnd, ParamEnv};
@ -17,27 +17,30 @@ use crate::ty::layout::VariantIdx;
use crate::util::captures::Captures;
use crate::mir::interpret::{Scalar, GlobalId};
use polonius_engine::Atom;
use rustc_index::vec::Idx;
use rustc_macros::HashStable;
use rustc_target::spec::abi;
use smallvec::SmallVec;
use std::borrow::Cow;
use std::cmp::Ordering;
use std::marker::PhantomData;
use std::ops::Range;
use rustc_target::spec::abi;
use syntax::ast::{self, Ident};
use syntax::symbol::{kw, Symbol};
use self::InferTy::*;
use self::TyKind::*;
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable)]
#[derive(HashStable, TypeFoldable, Lift)]
#[derive(
Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable,
HashStable, TypeFoldable, Lift,
)]
pub struct TypeAndMut<'tcx> {
pub ty: Ty<'tcx>,
pub mutbl: hir::Mutability,
}
#[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
RustcEncodable, RustcDecodable, Copy, HashStable)]
#[derive(
Clone, PartialEq, PartialOrd, Eq, Ord, Hash, RustcEncodable, RustcDecodable, Copy, HashStable,
)]
/// A "free" region `fr` can be interpreted as "some region
/// at least as big as the scope `fr.scope`".
pub struct FreeRegion {
@ -45,8 +48,9 @@ pub struct FreeRegion {
pub bound_region: BoundRegion,
}
#[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
RustcEncodable, RustcDecodable, Copy, HashStable)]
#[derive(
Clone, PartialEq, PartialOrd, Eq, Ord, Hash, RustcEncodable, RustcDecodable, Copy, HashStable,
)]
pub enum BoundRegion {
/// An anonymous region parameter for a given fn (&T)
BrAnon(u32),
@ -471,18 +475,18 @@ impl<'tcx> GeneratorSubsts<'tcx> {
}
impl<'tcx> GeneratorSubsts<'tcx> {
/// Generator have not been resumed yet
/// Generator has not been resumed yet.
pub const UNRESUMED: usize = 0;
/// Generator has returned / is completed
/// Generator has returned or is completed.
pub const RETURNED: usize = 1;
/// Generator has been poisoned
/// Generator has been poisoned.
pub const POISONED: usize = 2;
const UNRESUMED_NAME: &'static str = "Unresumed";
const RETURNED_NAME: &'static str = "Returned";
const POISONED_NAME: &'static str = "Panicked";
/// The valid variant indices of this Generator.
/// The valid variant indices of this generator.
#[inline]
pub fn variant_range(&self, def_id: DefId, tcx: TyCtxt<'tcx>) -> Range<VariantIdx> {
// FIXME requires optimized MIR
@ -490,7 +494,7 @@ impl<'tcx> GeneratorSubsts<'tcx> {
(VariantIdx::new(0)..VariantIdx::new(num_variants))
}
/// The discriminant for the given variant. Panics if the variant_index is
/// The discriminant for the given variant. Panics if the `variant_index` is
/// out of range.
#[inline]
pub fn discriminant_for_variant(
@ -505,7 +509,7 @@ impl<'tcx> GeneratorSubsts<'tcx> {
Discr { val: variant_index.as_usize() as u128, ty: self.discr_ty(tcx) }
}
/// The set of all discriminants for the Generator, enumerated with their
/// The set of all discriminants for the generator, enumerated with their
/// variant indices.
#[inline]
pub fn discriminants(
@ -670,12 +674,12 @@ impl<'tcx> List<ExistentialPredicate<'tcx>> {
pub fn principal(&self) -> Option<ExistentialTraitRef<'tcx>> {
match self[0] {
ExistentialPredicate::Trait(tr) => Some(tr),
_ => None
_ => None,
}
}
pub fn principal_def_id(&self) -> Option<DefId> {
self.principal().map(|d| d.def_id)
self.principal().map(|trait_ref| trait_ref.def_id)
}
#[inline]
@ -684,7 +688,7 @@ impl<'tcx> List<ExistentialPredicate<'tcx>> {
{
self.iter().filter_map(|predicate| {
match *predicate {
ExistentialPredicate::Projection(p) => Some(p),
ExistentialPredicate::Projection(projection) => Some(projection),
_ => None,
}
})
@ -694,8 +698,8 @@ impl<'tcx> List<ExistentialPredicate<'tcx>> {
pub fn auto_traits<'a>(&'a self) -> impl Iterator<Item = DefId> + 'a {
self.iter().filter_map(|predicate| {
match *predicate {
ExistentialPredicate::AutoTrait(d) => Some(d),
_ => None
ExistentialPredicate::AutoTrait(did) => Some(did),
_ => None,
}
})
}
@ -722,7 +726,8 @@ impl<'tcx> Binder<&'tcx List<ExistentialPredicate<'tcx>>> {
}
pub fn iter<'a>(&'a self)
-> impl DoubleEndedIterator<Item = Binder<ExistentialPredicate<'tcx>>> + 'tcx {
-> impl DoubleEndedIterator<Item = Binder<ExistentialPredicate<'tcx>>> + 'tcx
{
self.skip_binder().iter().cloned().map(Binder::bind)
}
}
@ -751,7 +756,7 @@ pub struct TraitRef<'tcx> {
impl<'tcx> TraitRef<'tcx> {
pub fn new(def_id: DefId, substs: SubstsRef<'tcx>) -> TraitRef<'tcx> {
TraitRef { def_id: def_id, substs: substs }
TraitRef { def_id, substs }
}
/// Returns a `TraitRef` of the form `P0: Foo<P1..Pn>` where `Pi`
@ -1296,7 +1301,7 @@ pub enum RegionKind {
/// A region variable. Should not exist after typeck.
ReVar(RegionVid),
/// A placeholder region - basically the higher-ranked version of ReFree.
/// A placeholder region -- basically, the higher-ranked version of `ReFree`.
/// Should not exist after typeck.
RePlaceholder(ty::PlaceholderRegion),
@ -1807,14 +1812,14 @@ impl<'tcx> TyS<'tcx> {
match self.kind {
Array(ty, _) | Slice(ty) => ty,
Str => tcx.mk_mach_uint(ast::UintTy::U8),
_ => bug!("sequence_element_type called on non-sequence value: {}", self),
_ => bug!("`sequence_element_type` called on non-sequence value: {}", self),
}
}
pub fn simd_type(&self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
match self.kind {
Adt(def, substs) => def.non_enum_variant().fields[0].ty(tcx, substs),
_ => bug!("simd_type called on invalid type")
_ => bug!("`simd_type` called on invalid type"),
}
}
@ -1823,7 +1828,7 @@ impl<'tcx> TyS<'tcx> {
// allow `#[repr(simd)] struct Simd<T, const N: usize>([T; N]);`.
match self.kind {
Adt(def, _) => def.non_enum_variant().fields.len() as u64,
_ => bug!("simd_size called on invalid type")
_ => bug!("`simd_size` called on invalid type"),
}
}
@ -1833,7 +1838,7 @@ impl<'tcx> TyS<'tcx> {
let variant = def.non_enum_variant();
(variant.fields.len() as u64, variant.fields[0].ty(tcx, substs))
}
_ => bug!("simd_size_and_type called on invalid type")
_ => bug!("`simd_size_and_type` called on invalid type"),
}
}
@ -1894,7 +1899,7 @@ impl<'tcx> TyS<'tcx> {
}
}
/// panics if called on any type other than `Box<T>`
/// Panics if called on any type other than `Box<T>`.
pub fn boxed_ty(&self) -> Ty<'tcx> {
match self.kind {
Adt(def, substs) if def.is_box() => substs.type_at(0),
@ -2114,7 +2119,8 @@ impl<'tcx> TyS<'tcx> {
}
/// If the type contains variants, returns the valid range of variant indices.
/// FIXME This requires the optimized MIR in the case of generators.
//
// FIXME: This requires the optimized MIR in the case of generators.
#[inline]
pub fn variant_range(&self, tcx: TyCtxt<'tcx>) -> Option<Range<VariantIdx>> {
match self.kind {
@ -2127,7 +2133,8 @@ impl<'tcx> TyS<'tcx> {
/// If the type contains variants, returns the variant for `variant_index`.
/// Panics if `variant_index` is out of range.
/// FIXME This requires the optimized MIR in the case of generators.
//
// FIXME: This requires the optimized MIR in the case of generators.
#[inline]
pub fn discriminant_for_variant(
&self,
@ -2142,7 +2149,7 @@ impl<'tcx> TyS<'tcx> {
}
}
/// Push onto `out` the regions directly referenced from this type (but not
/// Pushes onto `out` the regions directly referenced from this type (but not
/// types reachable from this type via `walk_tys`). This ignores late-bound
/// regions binders.
pub fn push_regions(&self, out: &mut SmallVec<[ty::Region<'tcx>; 4]>) {
@ -2255,7 +2262,7 @@ impl<'tcx> TyS<'tcx> {
ty::Infer(ty::FreshTy(_)) |
ty::Infer(ty::FreshIntTy(_)) |
ty::Infer(ty::FreshFloatTy(_)) =>
bug!("is_trivially_sized applied to unexpected type: {:?}", self),
bug!("`is_trivially_sized` applied to unexpected type: {:?}", self),
}
}
}

6
src/librustc/ty/util.rs
View file

@ -333,14 +333,14 @@ impl<'tcx> TyCtxt<'tcx> {
ty
}
/// Same as applying struct_tail on `source` and `target`, but only
/// Same as applying `struct_tail` on `source` and `target`, but only
/// keeps going as long as the two types are instances of the same
/// structure definitions.
/// For `(Foo<Foo<T>>, Foo<dyn Trait>)`, the result will be `(Foo<T>, Trait)`,
/// whereas struct_tail produces `T`, and `Trait`, respectively.
///
/// Should only be called if the types have no inference variables and do
/// not need their lifetimes preserved (e.g. as part of codegen); otherwise
/// not need their lifetimes preserved (e.g., as part of codegen); otherwise,
/// normalization attempt may cause compiler bugs.
pub fn struct_lockstep_tails_erasing_lifetimes(self,
source: Ty<'tcx>,
@ -353,7 +353,7 @@ impl<'tcx> TyCtxt<'tcx> {
source, target, |ty| tcx.normalize_erasing_regions(param_env, ty))
}
/// Same as applying struct_tail on `source` and `target`, but only
/// Same as applying `struct_tail` on `source` and `target`, but only
/// keeps going as long as the two types are instances of the same
/// structure definitions.
/// For `(Foo<Foo<T>>, Foo<dyn Trait>)`, the result will be `(Foo<T>, Trait)`,

11
src/librustc_codegen_llvm/abi.rs
View file

@ -1,16 +1,15 @@
use crate::llvm::{self, AttributePlace};
use crate::builder::Builder;
use crate::context::CodegenCx;
use crate::llvm::{self, AttributePlace};
use crate::type_::Type;
use crate::type_of::LayoutLlvmExt;
use crate::value::Value;
use crate::type_of::{LayoutLlvmExt};
use rustc_codegen_ssa::MemFlags;
use rustc_codegen_ssa::mir::place::PlaceRef;
use rustc_codegen_ssa::mir::operand::OperandValue;
use rustc_target::abi::call::ArgAbi;
use rustc_codegen_ssa::traits::*;
use rustc_target::abi::call::ArgAbi;
use rustc_target::abi::{HasDataLayout, LayoutOf};
use rustc::ty::{Ty};
use rustc::ty::layout::{self};
@ -202,7 +201,7 @@ impl ArgAbiExt<'ll, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
if self.is_sized_indirect() {
OperandValue::Ref(val, None, self.layout.align.abi).store(bx, dst)
} else if self.is_unsized_indirect() {
bug!("unsized ArgAbi must be handled through store_fn_arg");
bug!("unsized `ArgAbi` must be handled through `store_fn_arg`");
} else if let PassMode::Cast(cast) = self.mode {
// FIXME(eddyb): Figure out when the simpler Store is safe, clang
// uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}.

2
src/librustc_codegen_llvm/debuginfo/doc.rs
View file

@ -140,7 +140,7 @@
//! In order for link-time optimization to work properly, LLVM needs a unique
//! type identifier that tells it across compilation units which types are the
//! same as others. This type identifier is created by
//! TypeMap::get_unique_type_id_of_type() using the following algorithm:
//! `TypeMap::get_unique_type_id_of_type()` using the following algorithm:
//!
//! (1) Primitive types have their name as ID
//! (2) Structs, enums and traits have a multipart identifier

251
src/librustc_codegen_llvm/debuginfo/metadata.rs
View file

@ -7,16 +7,16 @@ use super::utils::{debug_context, DIB, span_start,
use super::namespace::mangled_name_of_instance;
use super::type_names::compute_debuginfo_type_name;
use super::CrateDebugContext;
use crate::abi;
use crate::value::Value;
use rustc_codegen_ssa::traits::*;
use crate::abi;
use crate::common::CodegenCx;
use crate::llvm;
use crate::llvm::debuginfo::{DIArray, DIType, DIFile, DIScope, DIDescriptor,
DICompositeType, DILexicalBlock, DIFlags, DebugEmissionKind};
use crate::llvm_util;
use crate::value::Value;
use crate::common::CodegenCx;
use rustc_codegen_ssa::traits::*;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc::hir::CodegenFnAttrFlags;
use rustc::hir::def::CtorKind;
@ -36,6 +36,9 @@ use rustc::util::nodemap::FxHashMap;
use rustc_fs_util::path_to_c_string;
use rustc_data_structures::small_c_str::SmallCStr;
use rustc_target::abi::HasDataLayout;
use syntax::ast;
use syntax::symbol::{Interner, Symbol};
use syntax_pos::{self, Span, FileName};
use libc::{c_uint, c_longlong};
use std::collections::hash_map::Entry;
@ -45,9 +48,6 @@ use std::hash::{Hash, Hasher};
use std::iter;
use std::ptr;
use std::path::{Path, PathBuf};
use syntax::ast;
use syntax::symbol::{Interner, Symbol};
use syntax_pos::{self, Span, FileName};
impl PartialEq for llvm::Metadata {
fn eq(&self, other: &Self) -> bool {
@ -70,7 +70,7 @@ impl fmt::Debug for llvm::Metadata {
}
// From DWARF 5.
// See http://www.dwarfstd.org/ShowIssue.php?issue=140129.1
// See http://www.dwarfstd.org/ShowIssue.php?issue=140129.1.
const DW_LANG_RUST: c_uint = 0x1c;
#[allow(non_upper_case_globals)]
const DW_ATE_boolean: c_uint = 0x02;
@ -91,70 +91,70 @@ pub const NO_SCOPE_METADATA: Option<&DIScope> = None;
#[derive(Copy, Debug, Hash, Eq, PartialEq, Clone)]
pub struct UniqueTypeId(ast::Name);
// The TypeMap is where the CrateDebugContext holds the type metadata nodes
// created so far. The metadata nodes are indexed by UniqueTypeId, and, for
// faster lookup, also by Ty. The TypeMap is responsible for creating
// UniqueTypeIds.
/// The `TypeMap` is where the `CrateDebugContext` holds the type metadata nodes
/// created so far. The metadata nodes are indexed by `UniqueTypeId`, and, for
/// faster lookup, also by `Ty`. The `TypeMap` is responsible for creating
/// `UniqueTypeId`s.
#[derive(Default)]
pub struct TypeMap<'ll, 'tcx> {
// The UniqueTypeIds created so far
/// The `UniqueTypeId`s created so far.
unique_id_interner: Interner,
// A map from UniqueTypeId to debuginfo metadata for that type. This is a 1:1 mapping.
/// A map from `UniqueTypeId` to debuginfo metadata for that type. This is a 1:1 mapping.
unique_id_to_metadata: FxHashMap<UniqueTypeId, &'ll DIType>,
// A map from types to debuginfo metadata. This is a N:1 mapping.
/// A map from types to debuginfo metadata. This is an N:1 mapping.
type_to_metadata: FxHashMap<Ty<'tcx>, &'ll DIType>,
// A map from types to UniqueTypeId. This is a N:1 mapping.
/// A map from types to `UniqueTypeId`. This is an N:1 mapping.
type_to_unique_id: FxHashMap<Ty<'tcx>, UniqueTypeId>
}
impl TypeMap<'ll, 'tcx> {
// Adds a Ty to metadata mapping to the TypeMap. The method will fail if
// the mapping already exists.
/// Adds a Ty to metadata mapping to the TypeMap. The method will fail if
/// the mapping already exists.
fn register_type_with_metadata(
&mut self,
type_: Ty<'tcx>,
metadata: &'ll DIType,
) {
if self.type_to_metadata.insert(type_, metadata).is_some() {
bug!("Type metadata for Ty '{}' is already in the TypeMap!", type_);
bug!("type metadata for `Ty` '{}' is already in the `TypeMap`!", type_);
}
}
// Removes a Ty to metadata mapping
// This is useful when computing the metadata for a potentially
// recursive type (e.g. a function ptr of the form:
//
// fn foo() -> impl Copy { foo }
//
// This kind of type cannot be properly represented
// via LLVM debuginfo. As a workaround,
// we register a temporary Ty to metadata mapping
// for the function before we compute its actual metadata.
// If the metadata computation ends up recursing back to the
// original function, it will use the temporary mapping
// for the inner self-reference, preventing us from
// recursing forever.
//
// This function is used to remove the temporary metadata
// mapping after we've computed the actual metadata
/// Removes a `Ty`-to-metadata mapping.
/// This is useful when computing the metadata for a potentially
/// recursive type (e.g., a function pointer of the form:
///
/// fn foo() -> impl Copy { foo }
///
/// This kind of type cannot be properly represented
/// via LLVM debuginfo. As a workaround,
/// we register a temporary Ty to metadata mapping
/// for the function before we compute its actual metadata.
/// If the metadata computation ends up recursing back to the
/// original function, it will use the temporary mapping
/// for the inner self-reference, preventing us from
/// recursing forever.
///
/// This function is used to remove the temporary metadata
/// mapping after we've computed the actual metadata.
fn remove_type(
&mut self,
type_: Ty<'tcx>,
) {
if self.type_to_metadata.remove(type_).is_none() {
bug!("Type metadata Ty '{}' is not in the TypeMap!", type_);
bug!("type metadata `Ty` '{}' is not in the `TypeMap`!", type_);
}
}
// Adds a UniqueTypeId to metadata mapping to the TypeMap. The method will
// fail if the mapping already exists.
/// Adds a `UniqueTypeId` to metadata mapping to the `TypeMap`. The method will
/// fail if the mapping already exists.
fn register_unique_id_with_metadata(
&mut self,
unique_type_id: UniqueTypeId,
metadata: &'ll DIType,
) {
if self.unique_id_to_metadata.insert(unique_type_id, metadata).is_some() {
bug!("Type metadata for unique id '{}' is already in the TypeMap!",
bug!("type metadata for unique ID '{}' is already in the `TypeMap`!",
self.get_unique_type_id_as_string(unique_type_id));
}
}
@ -167,23 +167,23 @@ impl TypeMap<'ll, 'tcx> {
self.unique_id_to_metadata.get(&unique_type_id).cloned()
}
// Get the string representation of a UniqueTypeId. This method will fail if
// the id is unknown.
/// Gets the string representation of a `UniqueTypeId`. This method will fail if
/// the ID is unknown.
fn get_unique_type_id_as_string(&self, unique_type_id: UniqueTypeId) -> &str {
let UniqueTypeId(interner_key) = unique_type_id;
self.unique_id_interner.get(interner_key)
}
// Get the UniqueTypeId for the given type. If the UniqueTypeId for the given
// type has been requested before, this is just a table lookup. Otherwise an
// ID will be generated and stored for later lookup.
/// Gets the `UniqueTypeId` for the given type. If the `UniqueTypeId` for the given
/// type has been requested before, this is just a table lookup. Otherwise, an
/// ID will be generated and stored for later lookup.
fn get_unique_type_id_of_type<'a>(&mut self, cx: &CodegenCx<'a, 'tcx>,
type_: Ty<'tcx>) -> UniqueTypeId {
// Let's see if we already have something in the cache
// Let's see if we already have something in the cache.
if let Some(unique_type_id) = self.type_to_unique_id.get(&type_).cloned() {
return unique_type_id;
}
// if not, generate one
// If not, generate one.
// The hasher we are using to generate the UniqueTypeId. We want
// something that provides more than the 64 bits of the DefaultHasher.
@ -203,9 +203,9 @@ impl TypeMap<'ll, 'tcx> {
return UniqueTypeId(key);
}
// Get the UniqueTypeId for an enum variant. Enum variants are not really
// types of their own, so they need special handling. We still need a
// UniqueTypeId for them, since to debuginfo they *are* real types.
/// Gets the `UniqueTypeId` for an enum variant. Enum variants are not really
/// types of their own, so they need special handling. We still need a
/// `UniqueTypeId` for them, since to debuginfo they *are* real types.
fn get_unique_type_id_of_enum_variant<'a>(&mut self,
cx: &CodegenCx<'a, 'tcx>,
enum_type: Ty<'tcx>,
@ -219,9 +219,9 @@ impl TypeMap<'ll, 'tcx> {
UniqueTypeId(interner_key)
}
// Get the unique type id string for an enum variant part.
// Variant parts are not types and shouldn't really have their own id,
// but it makes set_members_of_composite_type() simpler.
/// Gets the unique type ID string for an enum variant part.
/// Variant parts are not types and shouldn't really have their own ID,
/// but it makes `set_members_of_composite_type()` simpler.
fn get_unique_type_id_str_of_enum_variant_part(&mut self, enum_type_id: UniqueTypeId) -> &str {
let variant_part_type_id = format!("{}_variant_part",
self.get_unique_type_id_as_string(enum_type_id));
@ -230,11 +230,11 @@ impl TypeMap<'ll, 'tcx> {
}
}
// A description of some recursive type. It can either be already finished (as
// with FinalMetadata) or it is not yet finished, but contains all information
// needed to generate the missing parts of the description. See the
// documentation section on Recursive Types at the top of this file for more
// information.
/// A description of some recursive type. It can either be already finished (as
/// with `FinalMetadata`) or it is not yet finished, but contains all information
/// needed to generate the missing parts of the description. See the
/// documentation section on Recursive Types at the top of this file for more
/// information.
enum RecursiveTypeDescription<'ll, 'tcx> {
UnfinishedMetadata {
unfinished_type: Ty<'tcx>,
@ -255,7 +255,7 @@ fn create_and_register_recursive_type_forward_declaration(
member_description_factory: MemberDescriptionFactory<'ll, 'tcx>,
) -> RecursiveTypeDescription<'ll, 'tcx> {
// Insert the stub into the TypeMap in order to allow for recursive references
// Insert the stub into the `TypeMap` in order to allow for recursive references.
let mut type_map = debug_context(cx).type_map.borrow_mut();
type_map.register_unique_id_with_metadata(unique_type_id, metadata_stub);
type_map.register_type_with_metadata(unfinished_type, metadata_stub);
@ -270,9 +270,9 @@ fn create_and_register_recursive_type_forward_declaration(
}
impl RecursiveTypeDescription<'ll, 'tcx> {
// Finishes up the description of the type in question (mostly by providing
// descriptions of the fields of the given type) and returns the final type
// metadata.
/// Finishes up the description of the type in question (mostly by providing
/// descriptions of the fields of the given type) and returns the final type
/// metadata.
fn finalize(&self, cx: &CodegenCx<'ll, 'tcx>) -> MetadataCreationResult<'ll> {
match *self {
FinalMetadata(metadata) => MetadataCreationResult::new(metadata, false),
@ -287,7 +287,7 @@ impl RecursiveTypeDescription<'ll, 'tcx> {
// the TypeMap so that recursive references are possible. This
// will always be the case if the RecursiveTypeDescription has
// been properly created through the
// create_and_register_recursive_type_forward_declaration()
// `create_and_register_recursive_type_forward_declaration()`
// function.
{
let type_map = debug_context(cx).type_map.borrow();
@ -314,8 +314,8 @@ impl RecursiveTypeDescription<'ll, 'tcx> {
}
}
// Returns from the enclosing function if the type metadata with the given
// unique id can be found in the type map
/// Returns from the enclosing function if the type metadata with the given
/// unique ID can be found in the type map.
macro_rules! return_if_metadata_created_in_meantime {
($cx: expr, $unique_type_id: expr) => (
if let Some(metadata) = debug_context($cx).type_map
@ -527,19 +527,19 @@ pub fn type_metadata(
t: Ty<'tcx>,
usage_site_span: Span,
) -> &'ll DIType {
// Get the unique type id of this type.
// Get the unique type ID of this type.
let unique_type_id = {
let mut type_map = debug_context(cx).type_map.borrow_mut();
// First, try to find the type in TypeMap. If we have seen it before, we
// First, try to find the type in `TypeMap`. If we have seen it before, we
// can exit early here.
match type_map.find_metadata_for_type(t) {
Some(metadata) => {
return metadata;
},
None => {
// The Ty is not in the TypeMap but maybe we have already seen
// The Ty is not in the `TypeMap` but maybe we have already seen
// an equivalent type (e.g., only differing in region arguments).
// In order to find out, generate the unique type id and look
// In order to find out, generate the unique type ID and look
// that up.
let unique_type_id = type_map.get_unique_type_id_of_type(cx, t);
match type_map.find_metadata_for_unique_id(unique_type_id) {
@ -647,15 +647,15 @@ pub fn type_metadata(
//
// fn foo() -> impl Copy { foo }
//
// See TypeMap::remove_type for more detals
// about the workaround
// See `TypeMap::remove_type` for more detals
// about the workaround.
let temp_type = {
unsafe {
// The choice of type here is pretty arbitrary -
// anything reading the debuginfo for a recursive
// type is going to see *somthing* weird - the only
// question is what exactly it will see
// question is what exactly it will see.
let (size, align) = cx.size_and_align_of(t);
llvm::LLVMRustDIBuilderCreateBasicType(
DIB(cx),
@ -677,7 +677,7 @@ pub fn type_metadata(
type_map.borrow_mut().remove_type(t);
// This is actually a function pointer, so wrap it in pointer DI
// This is actually a function pointer, so wrap it in pointer DI.
MetadataCreationResult::new(pointer_type_metadata(cx, t, fn_metadata), false)
}
@ -743,14 +743,14 @@ pub fn type_metadata(
let mut type_map = debug_context(cx).type_map.borrow_mut();
if already_stored_in_typemap {
// Also make sure that we already have a TypeMap entry for the unique type id.
// Also make sure that we already have a `TypeMap` entry for the unique type ID.
let metadata_for_uid = match type_map.find_metadata_for_unique_id(unique_type_id) {
Some(metadata) => metadata,
None => {
span_bug!(usage_site_span,
"Expected type metadata for unique \
type id '{}' to already be in \
the debuginfo::TypeMap but it \
"expected type metadata for unique \
type ID '{}' to already be in \
the `debuginfo::TypeMap` but it \
was not. (Ty = {})",
type_map.get_unique_type_id_as_string(unique_type_id),
t);
@ -761,9 +761,9 @@ pub fn type_metadata(
Some(metadata) => {
if metadata != metadata_for_uid {
span_bug!(usage_site_span,
"Mismatch between Ty and \
UniqueTypeId maps in \
debuginfo::TypeMap. \
"mismatch between `Ty` and \
`UniqueTypeId` maps in \
`debuginfo::TypeMap`. \
UniqueTypeId={}, Ty={}",
type_map.get_unique_type_id_as_string(unique_type_id),
t);
@ -851,7 +851,7 @@ fn basic_type_metadata(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) -> &'ll DIType {
ty::Float(float_ty) => {
(float_ty.name_str(), DW_ATE_float)
},
_ => bug!("debuginfo::basic_type_metadata - t is invalid type")
_ => bug!("debuginfo::basic_type_metadata - `t` is invalid type")
};
let (size, align) = cx.size_and_align_of(t);
@ -908,7 +908,7 @@ pub fn compile_unit_metadata(
};
// The OSX linker has an idiosyncrasy where it will ignore some debuginfo
// if multiple object files with the same DW_AT_name are linked together.
// if multiple object files with the same `DW_AT_name` are linked together.
// As a workaround we generate unique names for each object file. Those do
// not correspond to an actual source file but that should be harmless.
if tcx.sess.target.target.options.is_like_osx {
@ -935,11 +935,9 @@ pub fn compile_unit_metadata(
//
// This should actually be
//
// ```
// let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo);
// ```
//
// that is, we should set LLVM's emission kind to `LineTablesOnly` if
// That is, we should set LLVM's emission kind to `LineTablesOnly` if
// we are compiling with "limited" debuginfo. However, some of the
// existing tools relied on slightly more debuginfo being generated than
// would be the case with `LineTablesOnly`, and we did not want to break
@ -1029,8 +1027,8 @@ impl MetadataCreationResult<'ll> {
}
}
// Description of a type member, which can either be a regular field (as in
// structs or tuples) or an enum variant.
/// Description of a type member, which can either be a regular field (as in
/// structs or tuples) or an enum variant.
#[derive(Debug)]
struct MemberDescription<'ll> {
name: String,
@ -1067,10 +1065,10 @@ impl<'ll> MemberDescription<'ll> {
}
}
// A factory for MemberDescriptions. It produces a list of member descriptions
// for some record-like type. MemberDescriptionFactories are used to defer the
// creation of type member descriptions in order to break cycles arising from
// recursive type definitions.
/// A factory for `MemberDescription`s. It produces a list of member descriptions
/// for some record-like type. `MemberDescriptionFactory`s are used to defer the
/// creation of type member descriptions in order to break cycles arising from
/// recursive type definitions.
enum MemberDescriptionFactory<'ll, 'tcx> {
StructMDF(StructMemberDescriptionFactory<'tcx>),
TupleMDF(TupleMemberDescriptionFactory<'tcx>),
@ -1106,7 +1104,7 @@ impl MemberDescriptionFactory<'ll, 'tcx> {
// Structs
//=-----------------------------------------------------------------------------
// Creates MemberDescriptions for the fields of a struct
/// Creates `MemberDescription`s for the fields of a struct.
struct StructMemberDescriptionFactory<'tcx> {
ty: Ty<'tcx>,
variant: &'tcx ty::VariantDef,
@ -1177,7 +1175,7 @@ fn prepare_struct_metadata(
// Tuples
//=-----------------------------------------------------------------------------
// Creates MemberDescriptions for the fields of a tuple
/// Creates `MemberDescription`s for the fields of a tuple.
struct TupleMemberDescriptionFactory<'tcx> {
ty: Ty<'tcx>,
component_types: Vec<Ty<'tcx>>,
@ -1300,14 +1298,14 @@ fn prepare_union_metadata(
// Enums
//=-----------------------------------------------------------------------------
// DWARF variant support is only available starting in LLVM 8.
// Although the earlier enum debug info output did not work properly
// in all situations, it is better for the time being to continue to
// sometimes emit the old style rather than emit something completely
// useless when rust is compiled against LLVM 6 or older. LLVM 7
// contains an early version of the DWARF variant support, and will
// crash when handling the new debug info format. This function
// decides which representation will be emitted.
/// DWARF variant support is only available starting in LLVM 8.
/// Although the earlier enum debug info output did not work properly
/// in all situations, it is better for the time being to continue to
/// sometimes emit the old style rather than emit something completely
/// useless when rust is compiled against LLVM 6 or older. LLVM 7
/// contains an early version of the DWARF variant support, and will
/// crash when handling the new debug info format. This function
/// decides which representation will be emitted.
fn use_enum_fallback(cx: &CodegenCx<'_, '_>) -> bool {
// On MSVC we have to use the fallback mode, because LLVM doesn't
// lower variant parts to PDB.
@ -1318,11 +1316,11 @@ fn use_enum_fallback(cx: &CodegenCx<'_, '_>) -> bool {
|| llvm_util::get_major_version() < 8;
}
// Describes the members of an enum value: An enum is described as a union of
// structs in DWARF. This MemberDescriptionFactory provides the description for
// the members of this union; so for every variant of the given enum, this
// factory will produce one MemberDescription (all with no name and a fixed
// offset of zero bytes).
/// Describes the members of an enum value; an enum is described as a union of
/// structs in DWARF. This `MemberDescriptionFactory` provides the description for
/// the members of this union; so for every variant of the given enum, this
/// factory will produce one `MemberDescription` (all with no name and a fixed
/// offset of zero bytes).
struct EnumMemberDescriptionFactory<'ll, 'tcx> {
enum_type: Ty<'tcx>,
layout: TyLayout<'tcx>,
@ -1456,7 +1454,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
} => {
if fallback {
let variant = self.layout.for_variant(cx, dataful_variant);
// Create a description of the non-null variant
// Create a description of the non-null variant.
let (variant_type_metadata, member_description_factory) =
describe_enum_variant(cx,
variant,
@ -1566,9 +1564,9 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
}
}
// Creates MemberDescriptions for the fields of a single enum variant.
// Creates `MemberDescription`s for the fields of a single enum variant.
struct VariantMemberDescriptionFactory<'ll, 'tcx> {
// Cloned from the layout::Struct describing the variant.
/// Cloned from the `layout::Struct` describing the variant.
offsets: Vec<layout::Size>,
args: Vec<(String, Ty<'tcx>)>,
discriminant_type_metadata: Option<&'ll DIType>,
@ -1652,10 +1650,10 @@ impl<'tcx> VariantInfo<'tcx> {
}
}
// Returns a tuple of (1) type_metadata_stub of the variant, (2) a
// MemberDescriptionFactory for producing the descriptions of the
// fields of the variant. This is a rudimentary version of a full
// RecursiveTypeDescription.
/// Returns a tuple of (1) `type_metadata_stub` of the variant, (2) a
/// `MemberDescriptionFactory` for producing the descriptions of the
/// fields of the variant. This is a rudimentary version of a full
/// `RecursiveTypeDescription`.
fn describe_enum_variant(
cx: &CodegenCx<'ll, 'tcx>,
layout: layout::TyLayout<'tcx>,
@ -2088,8 +2086,7 @@ fn set_members_of_composite_type(cx: &CodegenCx<'ll, 'tcx>,
}
}
// Compute the type parameters for a type, if any, for the given
// metadata.
/// Computes the type parameters for a type, if any, for the given metadata.
fn compute_type_parameters(cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>) -> Option<&'ll DIArray> {
if let ty::Adt(def, substs) = ty.kind {
if !substs.types().next().is_none() {
@ -2134,9 +2131,9 @@ fn compute_type_parameters(cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>) -> Option<&'
}
}
// A convenience wrapper around LLVMRustDIBuilderCreateStructType(). Does not do
// any caching, does not add any fields to the struct. This can be done later
// with set_members_of_composite_type().
/// A convenience wrapper around `LLVMRustDIBuilderCreateStructType()`. Does not do
/// any caching, does not add any fields to the struct. This can be done later
/// with `set_members_of_composite_type()`.
fn create_struct_stub(
cx: &CodegenCx<'ll, 'tcx>,
struct_type: Ty<'tcx>,
@ -2151,9 +2148,9 @@ fn create_struct_stub(
debug_context(cx).type_map.borrow().get_unique_type_id_as_string(unique_type_id)
);
let metadata_stub = unsafe {
// LLVMRustDIBuilderCreateStructType() wants an empty array. A null
// `LLVMRustDIBuilderCreateStructType()` wants an empty array. A null
// pointer will lead to hard to trace and debug LLVM assertions
// later on in llvm/lib/IR/Value.cpp.
// later on in `llvm/lib/IR/Value.cpp`.
let empty_array = create_DIArray(DIB(cx), &[]);
llvm::LLVMRustDIBuilderCreateStructType(
@ -2189,9 +2186,9 @@ fn create_union_stub(
debug_context(cx).type_map.borrow().get_unique_type_id_as_string(unique_type_id)
);
let metadata_stub = unsafe {
// LLVMRustDIBuilderCreateUnionType() wants an empty array. A null
// `LLVMRustDIBuilderCreateUnionType()` wants an empty array. A null
// pointer will lead to hard to trace and debug LLVM assertions
// later on in llvm/lib/IR/Value.cpp.
// later on in `llvm/lib/IR/Value.cpp`.
let empty_array = create_DIArray(DIB(cx), &[]);
llvm::LLVMRustDIBuilderCreateUnionType(
@ -2231,8 +2228,8 @@ pub fn create_global_var_metadata(
}
let no_mangle = attrs.flags.contains(CodegenFnAttrFlags::NO_MANGLE);
// We may want to remove the namespace scope if we're in an extern block, see:
// https://github.com/rust-lang/rust/pull/46457#issuecomment-351750952
// We may want to remove the namespace scope if we're in an extern block (see
// https://github.com/rust-lang/rust/pull/46457#issuecomment-351750952).
let var_scope = get_namespace_for_item(cx, def_id);
let span = tcx.def_span(def_id);
@ -2287,9 +2284,9 @@ pub fn create_vtable_metadata(cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>, vtable: &
let type_metadata = type_metadata(cx, ty, syntax_pos::DUMMY_SP);
unsafe {
// LLVMRustDIBuilderCreateStructType() wants an empty array. A null
// `LLVMRustDIBuilderCreateStructType()` wants an empty array. A null
// pointer will lead to hard to trace and debug LLVM assertions
// later on in llvm/lib/IR/Value.cpp.
// later on in `llvm/lib/IR/Value.cpp`.
let empty_array = create_DIArray(DIB(cx), &[]);
let name = const_cstr!("vtable");
@ -2327,7 +2324,7 @@ pub fn create_vtable_metadata(cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>, vtable: &
}
}
// Creates an "extension" of an existing DIScope into another file.
/// Creates an "extension" of an existing `DIScope` into another file.
pub fn extend_scope_to_file(
cx: &CodegenCx<'ll, '_>,
scope_metadata: &'ll DIScope,

2
src/librustc_codegen_llvm/intrinsic.rs
View file

@ -152,7 +152,7 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
match scalar.value {
Primitive::Int(..) => {
if self.cx().size_of(ret_ty).bytes() < 4 {
// va_arg should not be called on a integer type
// `va_arg` should not be called on a integer type
// less than 4 bytes in length. If it is, promote
// the integer to a `i32` and truncate the result
// back to the smaller type.

69
src/librustc_codegen_ssa/base.rs
View file

@ -1,21 +1,32 @@
//! Codegen the completed AST to the LLVM IR.
//!
//! Some functions here, such as codegen_block and codegen_expr, return a value --
//! the result of the codegen to LLVM -- while others, such as codegen_fn
//! and mono_item, are called only for the side effect of adding a
//! Some functions here, such as `codegen_block` and `codegen_expr`, return a value --
//! the result of the codegen to LLVM -- while others, such as `codegen_fn`
//! and `mono_item`, are called only for the side effect of adding a
//! particular definition to the LLVM IR output we're producing.
//!
//! Hopefully useful general knowledge about codegen:
//!
//! * There's no way to find out the `Ty` type of a Value. Doing so
//! * There's no way to find out the `Ty` type of a `Value`. Doing so
//! would be "trying to get the eggs out of an omelette" (credit:
//! pcwalton). You can, instead, find out its `llvm::Type` by calling `val_ty`,
//! but one `llvm::Type` corresponds to many `Ty`s; for instance, `tup(int, int,
//! int)` and `rec(x=int, y=int, z=int)` will have the same `llvm::Type`.
use crate::{ModuleCodegen, ModuleKind, CachedModuleCodegen};
use crate::{CachedModuleCodegen, CrateInfo, MemFlags, ModuleCodegen, ModuleKind};
use crate::back::write::{
OngoingCodegen, start_async_codegen, submit_pre_lto_module_to_llvm,
submit_post_lto_module_to_llvm,
};
use crate::common::{RealPredicate, TypeKind, IntPredicate};
use crate::meth;
use crate::mir;
use crate::mir::operand::OperandValue;
use crate::mir::place::PlaceRef;
use crate::traits::*;
use rustc::dep_graph::cgu_reuse_tracker::CguReuse;
use rustc::hir;
use rustc::hir::def_id::{DefId, LOCAL_CRATE};
use rustc::middle::cstore::EncodedMetadata;
use rustc::middle::lang_items::StartFnLangItem;
@ -23,6 +34,7 @@ use rustc::middle::weak_lang_items;
use rustc::mir::mono::{CodegenUnitNameBuilder, CodegenUnit, MonoItem};
use rustc::ty::{self, Ty, TyCtxt, Instance};
use rustc::ty::layout::{self, Align, TyLayout, LayoutOf, VariantIdx, HasTyCtxt};
use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
use rustc::ty::query::Providers;
use rustc::middle::cstore::{self, LinkagePreference};
use rustc::util::common::{time, print_time_passes_entry, set_time_depth, time_depth};
@ -31,25 +43,12 @@ use rustc::session::Session;
use rustc::util::nodemap::FxHashMap;
use rustc_index::vec::Idx;
use rustc_codegen_utils::{symbol_names_test, check_for_rustc_errors_attr};
use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
use crate::mir::place::PlaceRef;
use crate::back::write::{OngoingCodegen, start_async_codegen, submit_pre_lto_module_to_llvm,
submit_post_lto_module_to_llvm};
use crate::{MemFlags, CrateInfo};
use crate::common::{RealPredicate, TypeKind, IntPredicate};
use crate::meth;
use crate::mir;
use crate::traits::*;
use syntax::attr;
use syntax_pos::Span;
use std::cmp;
use std::ops::{Deref, DerefMut};
use std::time::{Instant, Duration};
use syntax_pos::Span;
use syntax::attr;
use rustc::hir;
use crate::mir::operand::OperandValue;
pub fn bin_op_to_icmp_predicate(op: hir::BinOpKind,
signed: bool)
@ -116,9 +115,8 @@ pub fn compare_simd_types<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
/// Retrieves the information we are losing (making dynamic) in an unsizing
/// adjustment.
///
/// The `old_info` argument is a bit funny. It is intended for use
/// in an upcast, where the new vtable for an object will be derived
/// from the old one.
/// The `old_info` argument is a bit odd. It is intended for use in an upcast,
/// where the new vtable for an object will be derived from the old one.
pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
cx: &Cx,
source: Ty<'tcx>,
@ -140,16 +138,19 @@ pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
(_, &ty::Dynamic(ref data, ..)) => {
let vtable_ptr = cx.layout_of(cx.tcx().mk_mut_ptr(target))
.field(cx, FAT_PTR_EXTRA);
cx.const_ptrcast(meth::get_vtable(cx, source, data.principal()),
cx.backend_type(vtable_ptr))
cx.const_ptrcast(
meth::get_vtable(cx, source, data.principal()),
cx.backend_type(vtable_ptr),
)
}
_ => bug!("unsized_info: invalid unsizing {:?} -> {:?}",
source,
target),
_ => bug!(
"unsized_info: invalid unsizing {:?} -> {:?}",
source, target
),
}
}
/// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
/// Coerces `src` to `dst_ty`. `src_ty` must be a thin pointer.
pub fn unsize_thin_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
bx: &mut Bx,
src: Bx::Value,
@ -199,8 +200,8 @@ pub fn unsize_thin_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
}
}
/// Coerce `src`, which is a reference to a value of type `src_ty`,
/// to a value of type `dst_ty` and store the result in `dst`
/// Coerces `src`, which is a reference to a value of type `src_ty`,
/// to a value of type `dst_ty`, and stores the result in `dst`.
pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
bx: &mut Bx,
src: PlaceRef<'tcx, Bx::Value>,
@ -250,9 +251,11 @@ pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
}
}
}
_ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
_ => bug!(
"coerce_unsized_into: invalid coercion {:?} -> {:?}",
src_ty,
dst_ty),
dst_ty,
),
}
}

15
src/librustc_codegen_ssa/meth.rs
View file

@ -1,8 +1,7 @@
use rustc_target::abi::call::FnAbi;
use crate::traits::*;
use rustc::ty::{self, Ty, Instance};
use rustc_target::abi::call::FnAbi;
#[derive(Copy, Clone, Debug)]
pub struct VirtualIndex(u64);
@ -20,7 +19,7 @@ impl<'a, 'tcx> VirtualIndex {
self,
bx: &mut Bx,
llvtable: Bx::Value,
fn_abi: &FnAbi<'tcx, Ty<'tcx>>
fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
) -> Bx::Value {
// Load the data pointer from the object.
debug!("get_fn({:?}, {:?})", llvtable, self);
@ -33,7 +32,7 @@ impl<'a, 'tcx> VirtualIndex {
let gep = bx.inbounds_gep(llvtable, &[bx.const_usize(self.0)]);
let ptr = bx.load(gep, ptr_align);
bx.nonnull_metadata(ptr);
// Vtable loads are invariant
// Vtable loads are invariant.
bx.set_invariant_load(ptr);
ptr
}
@ -41,7 +40,7 @@ impl<'a, 'tcx> VirtualIndex {
pub fn get_usize<Bx: BuilderMethods<'a, 'tcx>>(
self,
bx: &mut Bx,
llvtable: Bx::Value
llvtable: Bx::Value,
) -> Bx::Value {
// Load the data pointer from the object.
debug!("get_int({:?}, {:?})", llvtable, self);
@ -50,7 +49,7 @@ impl<'a, 'tcx> VirtualIndex {
let usize_align = bx.tcx().data_layout.pointer_align.abi;
let gep = bx.inbounds_gep(llvtable, &[bx.const_usize(self.0)]);
let ptr = bx.load(gep, usize_align);
// Vtable loads are invariant
// Vtable loads are invariant.
bx.set_invariant_load(ptr);
ptr
}
@ -78,7 +77,7 @@ pub fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
return val;
}
// Not in the cache. Build it.
// Not in the cache; build it.
let nullptr = cx.const_null(cx.type_i8p());
let methods_root;
@ -105,7 +104,7 @@ pub fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
let layout = cx.layout_of(ty);
// /////////////////////////////////////////////////////////////////////////////////////////////
// If you touch this code, be sure to also make the corresponding changes to
// `get_vtable` in rust_mir/interpret/traits.rs
// `get_vtable` in `rust_mir/interpret/traits.rs`.
// /////////////////////////////////////////////////////////////////////////////////////////////
let components: Vec<_> = [
cx.get_fn_addr(Instance::resolve_drop_in_place(cx.tcx(), ty)),

18
src/librustc_codegen_ssa/mir/operand.rs
View file

@ -1,19 +1,18 @@
use super::{FunctionCx, LocalRef};
use super::place::PlaceRef;
use crate::MemFlags;
use crate::base;
use crate::glue;
use crate::traits::*;
use rustc::mir::interpret::{ConstValue, ErrorHandled, Pointer, Scalar};
use rustc::mir;
use rustc::ty;
use rustc::ty::layout::{self, Align, LayoutOf, TyLayout, Size};
use crate::base;
use crate::MemFlags;
use crate::glue;
use crate::traits::*;
use std::fmt;
use super::{FunctionCx, LocalRef};
use super::place::PlaceRef;
/// The representation of a Rust value. The enum variant is in fact
/// uniquely determined by the value's type, but is kept as a
/// safety check.
@ -343,6 +342,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandValue<V> {
}
}
}
pub fn store_unsized<Bx: BuilderMethods<'a, 'tcx, Value = V>>(
self,
bx: &mut Bx,

25
src/librustc_codegen_ssa/mir/place.rs
View file

@ -1,28 +1,28 @@
use super::{FunctionCx, LocalRef};
use super::operand::OperandValue;
use crate::MemFlags;
use crate::common::IntPredicate;
use crate::glue;
use crate::traits::*;
use rustc::ty::{self, Instance, Ty};
use rustc::ty::layout::{self, Align, TyLayout, LayoutOf, VariantIdx, HasTyCtxt};
use rustc::mir;
use rustc::mir::tcx::PlaceTy;
use crate::MemFlags;
use crate::common::IntPredicate;
use crate::glue;
use crate::traits::*;
use super::{FunctionCx, LocalRef};
use super::operand::OperandValue;
#[derive(Copy, Clone, Debug)]
pub struct PlaceRef<'tcx, V> {
/// Pointer to the contents of the place.
/// A pointer to the contents of the place.
pub llval: V,
/// This place's extra data if it is unsized, or null.
/// This place's extra data if it is unsized, or `None` if null.
pub llextra: Option<V>,
/// Monomorphized type of this place, including variant information.
/// The monomorphized type of this place, including variant information.
pub layout: TyLayout<'tcx>,
/// What alignment we know for this place.
/// The alignment we know for this place.
pub align: Align,
}
@ -107,7 +107,6 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
bug!("unexpected layout `{:#?}` in PlaceRef::len", self.layout)
}
}
}
impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {

55
src/librustc_codegen_ssa/mir/rvalue.rs
View file

@ -1,22 +1,22 @@
use super::{FunctionCx, LocalRef};
use super::operand::{OperandRef, OperandValue};
use super::place::PlaceRef;
use crate::base;
use crate::MemFlags;
use crate::common::{self, RealPredicate, IntPredicate};
use crate::traits::*;
use rustc::ty::{self, Ty, adjustment::{PointerCast}, Instance};
use rustc::ty::cast::{CastTy, IntTy};
use rustc::ty::layout::{self, LayoutOf, HasTyCtxt};
use rustc::mir;
use rustc::middle::lang_items::ExchangeMallocFnLangItem;
use rustc_apfloat::{ieee, Float, Status, Round};
use std::{u128, i128};
use syntax::symbol::sym;
use syntax::source_map::{DUMMY_SP, Span};
use crate::base;
use crate::MemFlags;
use crate::common::{self, RealPredicate, IntPredicate};
use crate::traits::*;
use super::{FunctionCx, LocalRef};
use super::operand::{OperandRef, OperandValue};
use super::place::PlaceRef;
use std::{u128, i128};
impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
pub fn codegen_rvalue(
@ -31,8 +31,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
match *rvalue {
mir::Rvalue::Use(ref operand) => {
let cg_operand = self.codegen_operand(&mut bx, operand);
// FIXME: consider not copying constants through stack. (fixable by codegenning
// constants into OperandValue::Ref, why don’t we do that yet if we don’t?)
// FIXME: consider not copying constants through stack. (Fixable by codegen'ing
// constants into `OperandValue::Ref`; why don’t we do that yet if we don’t?)
cg_operand.val.store(&mut bx, dest);
bx
}
@ -41,7 +41,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
// The destination necessarily contains a fat pointer, so if
// it's a scalar pair, it's a fat pointer or newtype thereof.
if bx.cx().is_backend_scalar_pair(dest.layout) {
// into-coerce of a thin pointer to a fat pointer - just
// Into-coerce of a thin pointer to a fat pointer -- just
// use the operand path.
let (mut bx, temp) = self.codegen_rvalue_operand(bx, rvalue);
temp.val.store(&mut bx, dest);
@ -56,10 +56,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
match operand.val {
OperandValue::Pair(..) |
OperandValue::Immediate(_) => {
// unsize from an immediate structure. We don't
// Unsize from an immediate structure. We don't
// really need a temporary alloca here, but
// avoiding it would require us to have
// `coerce_unsized_into` use extractvalue to
// `coerce_unsized_into` use `extractvalue` to
// index into the struct, and this case isn't
// important enough for it.
debug!("codegen_rvalue: creating ugly alloca");
@ -74,7 +74,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
base::coerce_unsized_into(&mut bx, source, dest);
}
OperandValue::Ref(_, Some(_), _) => {
bug!("unsized coercion on an unsized rvalue")
bug!("unsized coercion on an unsized rvalue");
}
}
bx
@ -160,7 +160,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
bx
}
_ => bug!("unsized assignment other than Rvalue::Use"),
_ => bug!("unsized assignment other than `Rvalue::Use`"),
}
}
@ -220,17 +220,16 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
}
}
mir::CastKind::Pointer(PointerCast::UnsafeFnPointer) => {
// this is a no-op at the LLVM level
// This is a no-op at the LLVM level.
operand.val
}
mir::CastKind::Pointer(PointerCast::Unsize) => {
assert!(bx.cx().is_backend_scalar_pair(cast));
match operand.val {
OperandValue::Pair(lldata, llextra) => {
// unsize from a fat pointer - this is a
// unsize from a fat pointer -- this is a
// "trait-object-to-supertrait" coercion, for
// example,
// &'a fmt::Debug+Send => &'a fmt::Debug,
// example, `&'a fmt::Debug + Send => &'a fmt::Debug`.
// HACK(eddyb) have to bitcast pointers
// until LLVM removes pointee types.
@ -245,13 +244,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
OperandValue::Pair(lldata, llextra)
}
OperandValue::Ref(..) => {
bug!("by-ref operand {:?} in codegen_rvalue_operand",
bug!("by-ref operand {:?} in `codegen_rvalue_operand`",
operand);
}
}
}
mir::CastKind::Pointer(PointerCast::MutToConstPointer)
| mir::CastKind::Misc if bx.cx().is_backend_scalar_pair(operand.layout) => {
mir::CastKind::Pointer(PointerCast::MutToConstPointer) |
mir::CastKind::Misc if bx.cx().is_backend_scalar_pair(operand.layout) => {
if let OperandValue::Pair(data_ptr, meta) = operand.val {
if bx.cx().is_backend_scalar_pair(cast) {
let data_cast = bx.pointercast(data_ptr,
@ -265,12 +264,12 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
OperandValue::Immediate(llval)
}
} else {
bug!("Unexpected non-Pair operand")
bug!("unexpected non-pair operand");
}
}
mir::CastKind::Pointer(PointerCast::MutToConstPointer)
| mir::CastKind::Pointer(PointerCast::ArrayToPointer)
| mir::CastKind::Misc => {
mir::CastKind::Pointer(PointerCast::MutToConstPointer) |
mir::CastKind::Pointer(PointerCast::ArrayToPointer) |
mir::CastKind::Misc => {
assert!(bx.cx().is_backend_immediate(cast));
let ll_t_out = bx.cx().immediate_backend_type(cast);
if operand.layout.abi.is_uninhabited() {

11
src/librustc_codegen_ssa/traits/backend.rs
View file

@ -1,17 +1,18 @@
use rustc::ty::layout::{HasTyCtxt, LayoutOf, TyLayout};
use rustc::ty::Ty;
use super::write::WriteBackendMethods;
use super::CodegenObject;
use rustc::ty::layout::{HasTyCtxt, LayoutOf, TyLayout};
use rustc::ty::Ty;
use rustc::middle::cstore::EncodedMetadata;
use rustc::session::{Session, config};
use rustc::ty::TyCtxt;
use rustc_codegen_utils::codegen_backend::CodegenBackend;
use std::sync::Arc;
use std::sync::mpsc;
use syntax::expand::allocator::AllocatorKind;
use syntax_pos::symbol::Symbol;
use std::sync::Arc;
use std::sync::mpsc;
pub trait BackendTypes {
type Value: CodegenObject;
type Function: CodegenObject;

5
src/librustc_codegen_ssa/traits/builder.rs
View file

@ -4,14 +4,17 @@ use super::debuginfo::DebugInfoBuilderMethods;
use super::intrinsic::IntrinsicCallMethods;
use super::type_::ArgAbiMethods;
use super::{HasCodegen, StaticBuilderMethods};
use crate::common::{AtomicOrdering, AtomicRmwBinOp, IntPredicate, RealPredicate,
SynchronizationScope};
use crate::mir::operand::OperandRef;
use crate::mir::place::PlaceRef;
use crate::MemFlags;
use rustc::ty::Ty;
use rustc::ty::layout::{Align, Size, HasParamEnv};
use rustc_target::spec::{HasTargetSpec};
use rustc_target::spec::HasTargetSpec;
use std::ops::Range;
use std::iter::TrustedLen;

4
src/librustc_codegen_ssa/traits/mod.rs
View file

@ -41,9 +41,9 @@ pub use self::type_::{
ArgAbiMethods, BaseTypeMethods, DerivedTypeMethods, LayoutTypeMethods, TypeMethods,
};
pub use self::write::{ModuleBufferMethods, ThinBufferMethods, WriteBackendMethods};
use rustc::ty::layout::{HasParamEnv, HasTyCtxt};
use rustc_target::spec::{HasTargetSpec};
use rustc::ty::layout::{HasParamEnv, HasTyCtxt};
use rustc_target::spec::HasTargetSpec;
use std::fmt;

2
src/librustc_errors/diagnostic.rs
View file

@ -224,7 +224,7 @@ impl Diagnostic {
}));
msg.push((format!("`{}", found_extra), Style::NoStyle));
// For now, just attach these as notes
// For now, just attach these as notes.
self.highlighted_note(msg);
self
}

1
src/librustc_mir/hair/cx/block.rs
View file

@ -1,6 +1,7 @@
use crate::hair::{self, *};
use crate::hair::cx::Cx;
use crate::hair::cx::to_ref::ToRef;
use rustc::middle::region;
use rustc::hir;
use rustc::ty;

4
src/librustc_mir/interpret/operand.rs
View file

@ -136,7 +136,7 @@ impl<Tag> Operand<Tag> {
#[derive(Copy, Clone, Debug, PartialEq)]
pub struct OpTy<'tcx, Tag=()> {
op: Operand<Tag>, // Keep this private, it helps enforce invariants
op: Operand<Tag>, // Keep this private; it helps enforce invariants.
pub layout: TyLayout<'tcx>,
}
@ -203,7 +203,7 @@ pub(super) fn from_known_layout<'tcx>(
if cfg!(debug_assertions) {
let layout2 = compute()?;
assert_eq!(layout.details, layout2.details,
"Mismatch in layout of supposedly equal-layout types {:?} and {:?}",
"mismatch in layout of supposedly equal-layout types {:?} and {:?}",
layout.ty, layout2.ty);
}
Ok(layout)

2
src/librustc_mir/interpret/place.rs
View file

@ -48,7 +48,7 @@ pub enum Place<Tag=(), Id=AllocId> {
#[derive(Copy, Clone, Debug)]
pub struct PlaceTy<'tcx, Tag=()> {
place: Place<Tag>, // Keep this private, it helps enforce invariants
place: Place<Tag>, // Keep this private; it helps enforce invariants.
pub layout: TyLayout<'tcx>,
}

20
src/librustc_mir/interpret/traits.rs
View file

@ -1,14 +1,14 @@
use super::{InterpCx, Machine, MemoryKind, FnVal};
use rustc::ty::{self, Ty, Instance, TypeFoldable};
use rustc::ty::layout::{Size, Align, LayoutOf, HasDataLayout};
use rustc::mir::interpret::{Scalar, Pointer, InterpResult, PointerArithmetic,};
use super::{InterpCx, Machine, MemoryKind, FnVal};
impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// Creates a dynamic vtable for the given type and vtable origin. This is used only for
/// objects.
///
/// The `trait_ref` encodes the erased self type. Hence if we are
/// The `trait_ref` encodes the erased self type. Hence, if we are
/// making an object `Foo<Trait>` from a value of type `Foo<T>`, then
/// `trait_ref` would map `T: Trait`.
pub fn get_vtable(
@ -51,7 +51,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
let ptr_align = self.tcx.data_layout.pointer_align.abi;
// /////////////////////////////////////////////////////////////////////////////////////////
// If you touch this code, be sure to also make the corresponding changes to
// `get_vtable` in rust_codegen_llvm/meth.rs
// `get_vtable` in `rust_codegen_llvm/meth.rs`.
// /////////////////////////////////////////////////////////////////////////////////////////
let vtable = self.memory.allocate(
ptr_size * (3 + methods.len() as u64),
@ -97,16 +97,16 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
Ok(vtable)
}
/// Resolve the function at the specified slot in the provided
/// Resolves the function at the specified slot in the provided
/// vtable. An index of '0' corresponds to the first method
/// declared in the trait of the provided vtable
/// declared in the trait of the provided vtable.
pub fn get_vtable_slot(
&self,
vtable: Scalar<M::PointerTag>,
idx: usize
) -> InterpResult<'tcx, FnVal<'tcx, M::ExtraFnVal>> {
let ptr_size = self.pointer_size();
// Skip over the 'drop_ptr', 'size', and 'align' fields
// Skip over the 'drop_ptr', 'size', and 'align' fields.
let vtable_slot = vtable.ptr_offset(ptr_size * (idx as u64 + 3), self)?;
let vtable_slot = self.memory.check_ptr_access(
vtable_slot,
@ -118,12 +118,12 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
Ok(self.memory.get_fn(fn_ptr)?)
}
/// Returns the drop fn instance as well as the actual dynamic type
/// Returns the drop fn instance as well as the actual dynamic type.
pub fn read_drop_type_from_vtable(
&self,
vtable: Scalar<M::PointerTag>,
) -> InterpResult<'tcx, (ty::Instance<'tcx>, Ty<'tcx>)> {
// we don't care about the pointee type, we just want a pointer
// We don't care about the pointee type; we just want a pointer.
let vtable = self.memory.check_ptr_access(
vtable,
self.tcx.data_layout.pointer_size,
@ -149,7 +149,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
vtable: Scalar<M::PointerTag>,
) -> InterpResult<'tcx, (Size, Align)> {
let pointer_size = self.pointer_size();
// We check for size = 3*ptr_size, that covers the drop fn (unused here),
// We check for `size = 3 * ptr_size`, which covers the drop fn (unused here),
// the size, and the align (which we read below).
let vtable = self.memory.check_ptr_access(
vtable,

47
src/librustc_mir/monomorphize/collector.rs
View file

@ -1,5 +1,5 @@
//! Mono Item Collection
//! ===========================
//! ====================
//!
//! This module is responsible for discovering all items that will contribute to
//! to code generation of the crate. The important part here is that it not only
@ -174,9 +174,10 @@
//! this is not implemented however: a mono item will be produced
//! regardless of whether it is actually needed or not.
use crate::monomorphize;
use rustc::hir::{self, CodegenFnAttrFlags};
use rustc::hir::itemlikevisit::ItemLikeVisitor;
use rustc::hir::def_id::{DefId, LOCAL_CRATE};
use rustc::mir::interpret::{AllocId, ConstValue};
use rustc::middle::lang_items::{ExchangeMallocFnLangItem, StartFnLangItem};
@ -189,8 +190,6 @@ use rustc::mir::{self, Location, PlaceBase, Static, StaticKind};
use rustc::mir::visit::Visitor as MirVisitor;
use rustc::mir::mono::{MonoItem, InstantiationMode};
use rustc::mir::interpret::{Scalar, GlobalId, GlobalAlloc, ErrorHandled};
use crate::monomorphize;
use rustc::util::nodemap::{FxHashSet, FxHashMap, DefIdMap};
use rustc::util::common::time;
@ -530,7 +529,6 @@ struct MirNeighborCollector<'a, 'tcx> {
}
impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
fn visit_rvalue(&mut self, rvalue: &mir::Rvalue<'tcx>, location: Location) {
debug!("visiting rvalue {:?}", *rvalue);
@ -698,7 +696,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
}
}
PlaceBase::Local(_) => {
// Locals have no relevance for collector
// Locals have no relevance for collector.
}
}
}
@ -752,7 +750,7 @@ fn visit_instance_use<'tcx>(
ty::InstanceDef::ReifyShim(..) |
ty::InstanceDef::Virtual(..) |
ty::InstanceDef::DropGlue(_, None) => {
// don't need to emit shim if we are calling directly.
// Don't need to emit shim if we are calling directly.
if !is_direct_call {
output.push(create_fn_mono_item(instance));
}
@ -769,8 +767,8 @@ fn visit_instance_use<'tcx>(
}
}
// Returns true if we should codegen an instance in the local crate.
// Returns false if we can just link to the upstream crate and therefore don't
// Returns `true` if we should codegen an instance in the local crate.
// Returns `false` if we can just link to the upstream crate and therefore don't
// need a mono item.
fn should_monomorphize_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) -> bool {
let def_id = match instance.def {
@ -786,24 +784,24 @@ fn should_monomorphize_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx
};
if tcx.is_foreign_item(def_id) {
// We can always link to foreign items
// We can always link to foreign items.
return false;
}
if def_id.is_local() {
// local items cannot be referred to locally without monomorphizing them locally
// Local items cannot be referred to locally without monomorphizing them locally.
return true;
}
if tcx.is_reachable_non_generic(def_id) ||
is_available_upstream_generic(tcx, def_id, instance.substs) {
// We can link to the item in question, no instance needed
// in this crate
// in this crate.
return false;
}
if !tcx.is_mir_available(def_id) {
bug!("Cannot create local mono-item for {:?}", def_id)
bug!("cannot create local mono-item for {:?}", def_id)
}
return true;
@ -823,7 +821,7 @@ fn should_monomorphize_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx
// If this instance has non-erasable parameters, it cannot be a shared
// monomorphization. Non-generic instances are already handled above
// by `is_reachable_non_generic()`
// by `is_reachable_non_generic()`.
if substs.non_erasable_generics().next().is_none() {
return false
}
@ -836,7 +834,7 @@ fn should_monomorphize_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx
}
}
/// For given pair of source and target type that occur in an unsizing coercion,
/// For a given pair of source and target type that occur in an unsizing coercion,
/// this function finds the pair of types that determines the vtable linking
/// them.
///
@ -930,10 +928,9 @@ fn find_vtable_types_for_unsizing<'tcx>(
source_fields.len() == target_fields.len());
find_vtable_types_for_unsizing(tcx,
source_fields[coerce_index].ty(tcx,
source_substs),
target_fields[coerce_index].ty(tcx,
target_substs))
source_fields[coerce_index].ty(tcx, source_substs),
target_fields[coerce_index].ty(tcx, target_substs)
)
}
_ => bug!("find_vtable_types_for_unsizing: invalid coercion {:?} -> {:?}",
source_ty,
@ -975,7 +972,7 @@ fn create_mono_items_for_vtable_methods<'tcx>(
output.extend(methods);
}
// Also add the destructor
// Also add the destructor.
visit_drop_use(tcx, impl_ty, false, output);
}
}
@ -1002,7 +999,7 @@ impl ItemLikeVisitor<'v> for RootCollector<'_, 'v> {
hir::ItemKind::TraitAlias(..) |
hir::ItemKind::OpaqueTy(..) |
hir::ItemKind::Mod(..) => {
// Nothing to do, just keep recursing...
// Nothing to do, just keep recursing.
}
hir::ItemKind::Impl(..) => {
@ -1075,7 +1072,7 @@ impl ItemLikeVisitor<'v> for RootCollector<'_, 'v> {
let def_id = self.tcx.hir().local_def_id(ii.hir_id);
self.push_if_root(def_id);
}
_ => { /* Nothing to do here */ }
_ => { /* nothing to do here */ }
}
}
}
@ -1095,7 +1092,7 @@ impl RootCollector<'_, 'v> {
}
}
/// If `def_id` represents a root, then push it onto the list of
/// If `def_id` represents a root, pushes it onto the list of
/// outputs. (Note that all roots must be monomorphic.)
fn push_if_root(&mut self, def_id: DefId) {
if self.is_root(def_id) {
@ -1217,7 +1214,7 @@ fn create_mono_items_for_default_impls<'tcx>(
}
}
/// Scan the miri alloc in order to find function calls, closures, and drop-glue
/// Scans the miri alloc in order to find function calls, closures, and drop-glue.
fn collect_miri<'tcx>(tcx: TyCtxt<'tcx>, alloc_id: AllocId, output: &mut Vec<MonoItem<'tcx>>) {
let alloc_kind = tcx.alloc_map.lock().get(alloc_id);
match alloc_kind {
@ -1244,7 +1241,7 @@ fn collect_miri<'tcx>(tcx: TyCtxt<'tcx>, alloc_id: AllocId, output: &mut Vec<Mon
}
}
/// Scan the MIR in order to find function calls, closures, and drop-glue
/// Scans the MIR in order to find function calls, closures, and drop-glue.
fn collect_neighbours<'tcx>(
tcx: TyCtxt<'tcx>,
instance: Instance<'tcx>,

2
src/librustc_mir/monomorphize/mod.rs
View file

@ -22,7 +22,7 @@ pub fn custom_coerce_unsize_info<'tcx>(
tcx.coerce_unsized_info(impl_def_id).custom_kind.unwrap()
}
vtable => {
bug!("invalid CoerceUnsized vtable: {:?}", vtable);
bug!("invalid `CoerceUnsized` vtable: {:?}", vtable);
}
}
}

12
src/librustc_typeck/check/writeback.rs
View file

@ -3,6 +3,7 @@
// substitutions.
use crate::check::FnCtxt;
use rustc::hir;
use rustc::hir::def_id::{DefId, DefIndex};
use rustc::hir::intravisit::{self, NestedVisitorMap, Visitor};
@ -12,10 +13,11 @@ use rustc::ty::fold::{TypeFoldable, TypeFolder};
use rustc::ty::{self, Ty, TyCtxt};
use rustc::util::nodemap::DefIdSet;
use rustc_data_structures::sync::Lrc;
use std::mem;
use syntax::symbol::sym;
use syntax_pos::Span;
use std::mem;
///////////////////////////////////////////////////////////////////////////
// Entry point
@ -481,8 +483,10 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
if let ty::Opaque(defin_ty_def_id, _substs) = definition_ty.kind {
if let hir::OpaqueTyOrigin::TypeAlias = opaque_defn.origin {
if def_id == defin_ty_def_id {
debug!("Skipping adding concrete definition for opaque type {:?} {:?}",
opaque_defn, defin_ty_def_id);
debug!(
"skipping adding concrete definition for opaque type {:?} {:?}",
opaque_defn, defin_ty_def_id
);
skip_add = true;
}
}
@ -507,7 +511,7 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
if old.concrete_type != definition_ty || old.substs != opaque_defn.substs {
span_bug!(
span,
"visit_opaque_types tried to write different types for the same \
"`visit_opaque_types` tried to write different types for the same \
opaque type: {:?}, {:?}, {:?}, {:?}",
def_id,
definition_ty,

15
src/test/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs
View file

@ -1,6 +1,5 @@
// Check that we can manually implement an object
// unsafe trait for its trait object
//
// Check that we can manually implement an object-unsafe trait for its trait object.
// run-pass
#![feature(object_safe_for_dispatch)]
@ -46,7 +45,7 @@ fn main() {
let mut res = String::new();
// Directly call static
// Directly call static.
res.push(Struct::stat()); // "A"
res.push(<dyn Bad>::stat()); // "AC"
@ -55,15 +54,13 @@ fn main() {
// These look similar enough...
let bad = unsafe { std::mem::transmute::<&dyn Good, &dyn Bad>(good) };
// Call virtual
// Call virtual.
res.push(s.virt()); // "ACB"
res.push(bad.virt()); // "ACBD"
// Indirectly call static
// Indirectly call static.
res.push(s.indirect()); // "ACBDA"
res.push(bad.indirect()); // "ACBDAC"
if &res != "ACBDAC" {
panic!();
}
assert_eq!(&res, "ACBDAC");
}

2
src/test/ui/traits/principal-less-trait-objects.rs
View file

@ -1,5 +1,5 @@
// run-pass
// Check that trait-objects without a principal codegen properly.
// Check that trait objects without a principal codegen properly.
use std::sync::atomic::{AtomicUsize, Ordering};
use std::mem;