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Auto merge of #111089 - Dylan-DPC:rollup-b8oj6du, r=Dylan-DPC

Browse source 
Rollup of 7 pull requests

Successful merges:

 - #105076 (Refactor core::char::EscapeDefault and co. structures)
 - #108161 (Add `ConstParamTy` trait)
 - #108668 (Stabilize debugger_visualizer)
 - #110512 (Fix elaboration with associated type bounds)
 - #110895 (Remove `all` in target_thread_local cfg)
 - #110955 (uplift `clippy::clone_double_ref` as `suspicious_double_ref_op`)
 - #111048 (Mark`feature(return_position_impl_trait_in_trait)` and`feature(async_fn_in_trait)` as not incomplete)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
This commit is contained in:
bors 2023-05-02 06:36:44 +00:00
commit 7b99493492
134 changed files with 1702 additions and 1156 deletions
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7
compiler/rustc_codegen_ssa/src/back/link.rs
View file

@ -40,7 +40,6 @@ use regex::Regex;
use tempfile::Builder as TempFileBuilder;
use itertools::Itertools;
use std::borrow::Borrow;
use std::cell::OnceCell;
use std::collections::BTreeSet;
use std::ffi::OsString;
@ -576,17 +575,17 @@ fn link_dwarf_object<'a>(
impl<Relocations> ThorinSession<Relocations> {
fn alloc_mmap(&self, data: Mmap) -> &Mmap {
(*self.arena_mmap.alloc(data)).borrow()
&*self.arena_mmap.alloc(data)
}
}
impl<Relocations> thorin::Session<Relocations> for ThorinSession<Relocations> {
fn alloc_data(&self, data: Vec<u8>) -> &[u8] {
(*self.arena_data.alloc(data)).borrow()
&*self.arena_data.alloc(data)
}
fn alloc_relocation(&self, data: Relocations) -> &Relocations {
(*self.arena_relocations.alloc(data)).borrow()
&*self.arena_relocations.alloc(data)
}
fn read_input(&self, path: &Path) -> std::io::Result<&[u8]> {

2
compiler/rustc_feature/src/accepted.rs
View file

@ -130,6 +130,8 @@ declare_features! (
(accepted, copy_closures, "1.26.0", Some(44490), None),
/// Allows `crate` in paths.
(accepted, crate_in_paths, "1.30.0", Some(45477), None),
/// Allows using `#[debugger_visualizer]` attribute.
(accepted, debugger_visualizer, "CURRENT_RUSTC_VERSION", Some(95939), None),
/// Allows rustc to inject a default alloc_error_handler
(accepted, default_alloc_error_handler, "1.68.0", Some(66741), None),
/// Allows using assigning a default type to type parameters in algebraic data type definitions.

6
compiler/rustc_feature/src/active.rs
View file

@ -310,7 +310,7 @@ declare_features! (
/// Allows `async || body` closures.
(active, async_closure, "1.37.0", Some(62290), None),
/// Allows async functions to be declared, implemented, and used in traits.
(incomplete, async_fn_in_trait, "1.66.0", Some(91611), None),
(active, async_fn_in_trait, "1.66.0", Some(91611), None),
/// Treat `extern "C"` function as nounwind.
(active, c_unwind, "1.52.0", Some(74990), None),
/// Allows using C-variadics.
@ -363,8 +363,6 @@ declare_features! (
(active, custom_inner_attributes, "1.30.0", Some(54726), None),
/// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`.
(active, custom_test_frameworks, "1.30.0", Some(50297), None),
/// Allows using `#[debugger_visualizer]`.
(active, debugger_visualizer, "1.62.0", Some(95939), None),
/// Allows declarative macros 2.0 (`macro`).
(active, decl_macro, "1.17.0", Some(39412), None),
/// Allows default type parameters to influence type inference.
@ -496,7 +494,7 @@ declare_features! (
/// Allows `repr(simd)` and importing the various simd intrinsics.
(active, repr_simd, "1.4.0", Some(27731), None),
/// Allows return-position `impl Trait` in traits.
(incomplete, return_position_impl_trait_in_trait, "1.65.0", Some(91611), None),
(active, return_position_impl_trait_in_trait, "1.65.0", Some(91611), None),
/// Allows bounding the return type of AFIT/RPITIT.
(incomplete, return_type_notation, "1.70.0", Some(109417), None),
/// Allows `extern "rust-cold"`.

12
compiler/rustc_feature/src/builtin_attrs.rs
View file

@ -403,16 +403,16 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
doc, Normal, template!(List: "hidden|inline|...", NameValueStr: "string"), DuplicatesOk
),
// Debugging
ungated!(
debugger_visualizer, Normal,
template!(List: r#"natvis_file = "...", gdb_script_file = "...""#), DuplicatesOk
),
// ==========================================================================
// Unstable attributes:
// ==========================================================================
// RFC #3191: #[debugger_visualizer] support
gated!(
debugger_visualizer, Normal, template!(List: r#"natvis_file = "...", gdb_script_file = "...""#),
DuplicatesOk, experimental!(debugger_visualizer)
),
// Linking:
gated!(
naked, Normal, template!(Word), WarnFollowing, @only_local: true,

2
compiler/rustc_hir/src/lang_items.rs
View file

@ -293,6 +293,8 @@ language_item_table! {
PointerLike, sym::pointer_like, pointer_like, Target::Trait, GenericRequirement::Exact(0);
ConstParamTy, sym::const_param_ty, const_param_ty_trait, Target::Trait, GenericRequirement::Exact(0);
Poll, sym::Poll, poll, Target::Enum, GenericRequirement::None;
PollReady, sym::Ready, poll_ready_variant, Target::Variant, GenericRequirement::None;
PollPending, sym::Pending, poll_pending_variant, Target::Variant, GenericRequirement::None;

4
compiler/rustc_hir_analysis/messages.ftl
View file

@ -35,6 +35,10 @@ hir_analysis_field_already_declared =
hir_analysis_expected_used_symbol = expected `used`, `used(compiler)` or `used(linker)`
hir_analysis_const_param_ty_impl_on_non_adt =
the trait `ConstParamTy` may not be implemented for this type
.label = type is not a structure or enumeration
hir_analysis_ambiguous_lifetime_bound =
ambiguous lifetime bound, explicit lifetime bound required

70
compiler/rustc_hir_analysis/src/astconv/mod.rs
View file

@ -56,6 +56,9 @@ use std::slice;
#[derive(Debug)]
pub struct PathSeg(pub DefId, pub usize);
#[derive(Copy, Clone, Debug)]
pub struct OnlySelfBounds(pub bool);
pub trait AstConv<'tcx> {
fn tcx(&self) -> TyCtxt<'tcx>;
@ -670,6 +673,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
args: &GenericArgs<'_>,
infer_args: bool,
self_ty: Ty<'tcx>,
only_self_bounds: OnlySelfBounds,
) -> GenericArgCountResult {
let (substs, arg_count) = self.create_substs_for_ast_path(
trait_ref_span,
@ -706,6 +710,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
&mut dup_bindings,
binding_span.unwrap_or(binding.span),
constness,
only_self_bounds,
);
// Okay to ignore `Err` because of `ErrorGuaranteed` (see above).
}
@ -741,6 +746,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
self_ty: Ty<'tcx>,
bounds: &mut Bounds<'tcx>,
speculative: bool,
only_self_bounds: OnlySelfBounds,
) -> GenericArgCountResult {
let hir_id = trait_ref.hir_ref_id;
let binding_span = None;
@ -766,6 +772,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
args,
infer_args,
self_ty,
only_self_bounds,
)
}
@ -777,6 +784,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
args: &GenericArgs<'_>,
self_ty: Ty<'tcx>,
bounds: &mut Bounds<'tcx>,
only_self_bounds: OnlySelfBounds,
) {
let binding_span = Some(span);
let constness = ty::BoundConstness::NotConst;
@ -799,6 +807,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
args,
infer_args,
self_ty,
only_self_bounds,
);
}
@ -947,6 +956,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
ast_bounds: I,
bounds: &mut Bounds<'tcx>,
bound_vars: &'tcx ty::List<ty::BoundVariableKind>,
only_self_bounds: OnlySelfBounds,
) {
for ast_bound in ast_bounds {
match ast_bound {
@ -964,11 +974,18 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
param_ty,
bounds,
false,
only_self_bounds,
);
}
&hir::GenericBound::LangItemTrait(lang_item, span, hir_id, args) => {
self.instantiate_lang_item_trait_ref(
lang_item, span, hir_id, args, param_ty, bounds,
lang_item,
span,
hir_id,
args,
param_ty,
bounds,
only_self_bounds,
);
}
hir::GenericBound::Outlives(lifetime) => {
@ -1006,8 +1023,19 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
&self,
param_ty: Ty<'tcx>,
ast_bounds: &[hir::GenericBound<'_>],
only_self_bounds: OnlySelfBounds,
) -> Bounds<'tcx> {
self.compute_bounds_inner(param_ty, ast_bounds)
let mut bounds = Bounds::default();
self.add_bounds(
param_ty,
ast_bounds.iter(),
&mut bounds,
ty::List::empty(),
only_self_bounds,
);
debug!(?bounds);
bounds
}
/// Convert the bounds in `ast_bounds` that refer to traits which define an associated type
@ -1029,17 +1057,14 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
}
}
self.compute_bounds_inner(param_ty, &result)
}
fn compute_bounds_inner(
&self,
param_ty: Ty<'tcx>,
ast_bounds: &[hir::GenericBound<'_>],
) -> Bounds<'tcx> {
let mut bounds = Bounds::default();
self.add_bounds(param_ty, ast_bounds.iter(), &mut bounds, ty::List::empty());
self.add_bounds(
param_ty,
result.iter(),
&mut bounds,
ty::List::empty(),
OnlySelfBounds(true),
);
debug!(?bounds);
bounds
@ -1062,6 +1087,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
dup_bindings: &mut FxHashMap<DefId, Span>,
path_span: Span,
constness: ty::BoundConstness,
only_self_bounds: OnlySelfBounds,
) -> Result<(), ErrorGuaranteed> {
// Given something like `U: SomeTrait<T = X>`, we want to produce a
// predicate like `<U as SomeTrait>::T = X`. This is somewhat
@ -1361,8 +1387,20 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
//
// Calling `skip_binder` is okay, because `add_bounds` expects the `param_ty`
// parameter to have a skipped binder.
let param_ty = tcx.mk_alias(ty::Projection, projection_ty.skip_binder());
self.add_bounds(param_ty, ast_bounds.iter(), bounds, projection_ty.bound_vars());
//
// NOTE: If `only_self_bounds` is true, do NOT expand this associated
// type bound into a trait predicate, since we only want to add predicates
// for the `Self` type.
if !only_self_bounds.0 {
let param_ty = tcx.mk_alias(ty::Projection, projection_ty.skip_binder());
self.add_bounds(
param_ty,
ast_bounds.iter(),
bounds,
projection_ty.bound_vars(),
only_self_bounds,
);
}
}
}
Ok(())
@ -1403,6 +1441,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
dummy_self,
&mut bounds,
false,
// FIXME: This should be `true`, but we don't really handle
// associated type bounds or type aliases in objects in a way
// that makes this meaningful, I think.
OnlySelfBounds(false),
) {
potential_assoc_types.extend(cur_potential_assoc_types);
}

255
compiler/rustc_hir_analysis/src/coherence/builtin.rs
View file

@ -1,9 +1,11 @@
//! Check properties that are required by built-in traits and set
//! up data structures required by type-checking/codegen.
use crate::errors::{CopyImplOnNonAdt, CopyImplOnTypeWithDtor, DropImplOnWrongItem};
use crate::errors::{
ConstParamTyImplOnNonAdt, CopyImplOnNonAdt, CopyImplOnTypeWithDtor, DropImplOnWrongItem,
};
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::{struct_span_err, MultiSpan};
use rustc_errors::{struct_span_err, ErrorGuaranteed, MultiSpan};
use rustc_hir as hir;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::lang_items::LangItem;
@ -14,9 +16,11 @@ use rustc_infer::infer::{DefineOpaqueTypes, TyCtxtInferExt};
use rustc_infer::traits::Obligation;
use rustc_middle::ty::adjustment::CoerceUnsizedInfo;
use rustc_middle::ty::{self, suggest_constraining_type_params, Ty, TyCtxt, TypeVisitableExt};
use rustc_span::Span;
use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
use rustc_trait_selection::traits::misc::{
type_allowed_to_implement_copy, CopyImplementationError, InfringingFieldsReason,
type_allowed_to_implement_const_param_ty, type_allowed_to_implement_copy,
ConstParamTyImplementationError, CopyImplementationError, InfringingFieldsReason,
};
use rustc_trait_selection::traits::ObligationCtxt;
use rustc_trait_selection::traits::{self, ObligationCause};
@ -27,6 +31,7 @@ pub fn check_trait(tcx: TyCtxt<'_>, trait_def_id: DefId) {
Checker { tcx, trait_def_id }
.check(lang_items.drop_trait(), visit_implementation_of_drop)
.check(lang_items.copy_trait(), visit_implementation_of_copy)
.check(lang_items.const_param_ty_trait(), visit_implementation_of_const_param_ty)
.check(lang_items.coerce_unsized_trait(), visit_implementation_of_coerce_unsized)
.check(lang_items.dispatch_from_dyn_trait(), visit_implementation_of_dispatch_from_dyn);
}
@ -83,110 +88,7 @@ fn visit_implementation_of_copy(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
match type_allowed_to_implement_copy(tcx, param_env, self_type, cause) {
Ok(()) => {}
Err(CopyImplementationError::InfringingFields(fields)) => {
let mut err = struct_span_err!(
tcx.sess,
span,
E0204,
"the trait `Copy` cannot be implemented for this type"
);
// We'll try to suggest constraining type parameters to fulfill the requirements of
// their `Copy` implementation.
let mut errors: BTreeMap<_, Vec<_>> = Default::default();
let mut bounds = vec![];
let mut seen_tys = FxHashSet::default();
for (field, ty, reason) in fields {
// Only report an error once per type.
if !seen_tys.insert(ty) {
continue;
}
let field_span = tcx.def_span(field.did);
err.span_label(field_span, "this field does not implement `Copy`");
match reason {
InfringingFieldsReason::Fulfill(fulfillment_errors) => {
for error in fulfillment_errors {
let error_predicate = error.obligation.predicate;
// Only note if it's not the root obligation, otherwise it's trivial and
// should be self-explanatory (i.e. a field literally doesn't implement Copy).
// FIXME: This error could be more descriptive, especially if the error_predicate
// contains a foreign type or if it's a deeply nested type...
if error_predicate != error.root_obligation.predicate {
errors
.entry((ty.to_string(), error_predicate.to_string()))
.or_default()
.push(error.obligation.cause.span);
}
if let ty::PredicateKind::Clause(ty::Clause::Trait(
ty::TraitPredicate {
trait_ref,
polarity: ty::ImplPolarity::Positive,
..
},
)) = error_predicate.kind().skip_binder()
{
let ty = trait_ref.self_ty();
if let ty::Param(_) = ty.kind() {
bounds.push((
format!("{ty}"),
trait_ref.print_only_trait_path().to_string(),
Some(trait_ref.def_id),
));
}
}
}
}
InfringingFieldsReason::Regions(region_errors) => {
for error in region_errors {
let ty = ty.to_string();
match error {
RegionResolutionError::ConcreteFailure(origin, a, b) => {
let predicate = format!("{b}: {a}");
errors
.entry((ty.clone(), predicate.clone()))
.or_default()
.push(origin.span());
if let ty::RegionKind::ReEarlyBound(ebr) = *b && ebr.has_name() {
bounds.push((b.to_string(), a.to_string(), None));
}
}
RegionResolutionError::GenericBoundFailure(origin, a, b) => {
let predicate = format!("{a}: {b}");
errors
.entry((ty.clone(), predicate.clone()))
.or_default()
.push(origin.span());
if let infer::region_constraints::GenericKind::Param(_) = a {
bounds.push((a.to_string(), b.to_string(), None));
}
}
_ => continue,
}
}
}
}
}
for ((ty, error_predicate), spans) in errors {
let span: MultiSpan = spans.into();
err.span_note(
span,
&format!("the `Copy` impl for `{}` requires that `{}`", ty, error_predicate),
);
}
suggest_constraining_type_params(
tcx,
tcx.hir().get_generics(impl_did).expect("impls always have generics"),
&mut err,
bounds.iter().map(|(param, constraint, def_id)| {
(param.as_str(), constraint.as_str(), *def_id)
}),
None,
);
err.emit();
infringing_fields_error(tcx, fields, LangItem::Copy, impl_did, span);
}
Err(CopyImplementationError::NotAnAdt) => {
tcx.sess.emit_err(CopyImplOnNonAdt { span });
@ -197,6 +99,29 @@ fn visit_implementation_of_copy(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
}
}
fn visit_implementation_of_const_param_ty(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
let self_type = tcx.type_of(impl_did).subst_identity();
assert!(!self_type.has_escaping_bound_vars());
let param_env = tcx.param_env(impl_did);
let span = match tcx.hir().expect_item(impl_did).expect_impl() {
hir::Impl { polarity: hir::ImplPolarity::Negative(_), .. } => return,
impl_ => impl_.self_ty.span,
};
let cause = traits::ObligationCause::misc(span, impl_did);
match type_allowed_to_implement_const_param_ty(tcx, param_env, self_type, cause) {
Ok(()) => {}
Err(ConstParamTyImplementationError::InfrigingFields(fields)) => {
infringing_fields_error(tcx, fields, LangItem::ConstParamTy, impl_did, span);
}
Err(ConstParamTyImplementationError::NotAnAdtOrBuiltinAllowed) => {
tcx.sess.emit_err(ConstParamTyImplOnNonAdt { span });
}
}
}
fn visit_implementation_of_coerce_unsized(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
debug!("visit_implementation_of_coerce_unsized: impl_did={:?}", impl_did);
@ -593,3 +518,119 @@ pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: LocalDefId) -> Coe
CoerceUnsizedInfo { custom_kind: kind }
}
fn infringing_fields_error(
tcx: TyCtxt<'_>,
fields: Vec<(&ty::FieldDef, Ty<'_>, InfringingFieldsReason<'_>)>,
lang_item: LangItem,
impl_did: LocalDefId,
impl_span: Span,
) -> ErrorGuaranteed {
let trait_did = tcx.require_lang_item(lang_item, Some(impl_span));
let trait_name = tcx.def_path_str(trait_did);
let mut err = struct_span_err!(
tcx.sess,
impl_span,
E0204,
"the trait `{trait_name}` cannot be implemented for this type"
);
// We'll try to suggest constraining type parameters to fulfill the requirements of
// their `Copy` implementation.
let mut errors: BTreeMap<_, Vec<_>> = Default::default();
let mut bounds = vec![];
let mut seen_tys = FxHashSet::default();
for (field, ty, reason) in fields {
// Only report an error once per type.
if !seen_tys.insert(ty) {
continue;
}
let field_span = tcx.def_span(field.did);
err.span_label(field_span, format!("this field does not implement `{trait_name}`"));
match reason {
InfringingFieldsReason::Fulfill(fulfillment_errors) => {
for error in fulfillment_errors {
let error_predicate = error.obligation.predicate;
// Only note if it's not the root obligation, otherwise it's trivial and
// should be self-explanatory (i.e. a field literally doesn't implement Copy).
// FIXME: This error could be more descriptive, especially if the error_predicate
// contains a foreign type or if it's a deeply nested type...
if error_predicate != error.root_obligation.predicate {
errors
.entry((ty.to_string(), error_predicate.to_string()))
.or_default()
.push(error.obligation.cause.span);
}
if let ty::PredicateKind::Clause(ty::Clause::Trait(ty::TraitPredicate {
trait_ref,
polarity: ty::ImplPolarity::Positive,
..
})) = error_predicate.kind().skip_binder()
{
let ty = trait_ref.self_ty();
if let ty::Param(_) = ty.kind() {
bounds.push((
format!("{ty}"),
trait_ref.print_only_trait_path().to_string(),
Some(trait_ref.def_id),
));
}
}
}
}
InfringingFieldsReason::Regions(region_errors) => {
for error in region_errors {
let ty = ty.to_string();
match error {
RegionResolutionError::ConcreteFailure(origin, a, b) => {
let predicate = format!("{b}: {a}");
errors
.entry((ty.clone(), predicate.clone()))
.or_default()
.push(origin.span());
if let ty::RegionKind::ReEarlyBound(ebr) = *b && ebr.has_name() {
bounds.push((b.to_string(), a.to_string(), None));
}
}
RegionResolutionError::GenericBoundFailure(origin, a, b) => {
let predicate = format!("{a}: {b}");
errors
.entry((ty.clone(), predicate.clone()))
.or_default()
.push(origin.span());
if let infer::region_constraints::GenericKind::Param(_) = a {
bounds.push((a.to_string(), b.to_string(), None));
}
}
_ => continue,
}
}
}
}
}
for ((ty, error_predicate), spans) in errors {
let span: MultiSpan = spans.into();
err.span_note(
span,
format!("the `{trait_name}` impl for `{ty}` requires that `{error_predicate}`"),
);
}
suggest_constraining_type_params(
tcx,
tcx.hir().get_generics(impl_did).expect("impls always have generics"),
&mut err,
bounds
.iter()
.map(|(param, constraint, def_id)| (param.as_str(), constraint.as_str(), *def_id)),
None,
);
err.emit()
}

6
compiler/rustc_hir_analysis/src/collect/item_bounds.rs
View file

@ -1,5 +1,5 @@
use super::ItemCtxt;
use crate::astconv::AstConv;
use crate::astconv::{AstConv, OnlySelfBounds};
use rustc_hir as hir;
use rustc_infer::traits::util;
use rustc_middle::ty::subst::InternalSubsts;
@ -26,7 +26,7 @@ fn associated_type_bounds<'tcx>(
);
let icx = ItemCtxt::new(tcx, assoc_item_def_id);
let mut bounds = icx.astconv().compute_bounds(item_ty, ast_bounds);
let mut bounds = icx.astconv().compute_bounds(item_ty, ast_bounds, OnlySelfBounds(false));
// Associated types are implicitly sized unless a `?Sized` bound is found
icx.astconv().add_implicitly_sized(&mut bounds, item_ty, ast_bounds, None, span);
@ -67,7 +67,7 @@ fn opaque_type_bounds<'tcx>(
) -> &'tcx [(ty::Predicate<'tcx>, Span)] {
ty::print::with_no_queries!({
let icx = ItemCtxt::new(tcx, opaque_def_id);
let mut bounds = icx.astconv().compute_bounds(item_ty, ast_bounds);
let mut bounds = icx.astconv().compute_bounds(item_ty, ast_bounds, OnlySelfBounds(false));
// Opaque types are implicitly sized unless a `?Sized` bound is found
icx.astconv().add_implicitly_sized(&mut bounds, item_ty, ast_bounds, None, span);
debug!(?bounds);

103
compiler/rustc_hir_analysis/src/collect/predicates_of.rs
View file

@ -1,4 +1,4 @@
use crate::astconv::AstConv;
use crate::astconv::{AstConv, OnlySelfBounds};
use crate::bounds::Bounds;
use crate::collect::ItemCtxt;
use crate::constrained_generic_params as cgp;
@ -14,9 +14,6 @@ use rustc_middle::ty::{GenericPredicates, ToPredicate};
use rustc_span::symbol::{sym, Ident};
use rustc_span::{Span, DUMMY_SP};
#[derive(Debug)]
struct OnlySelfBounds(bool);
/// Returns a list of all type predicates (explicit and implicit) for the definition with
/// ID `def_id`. This includes all predicates returned by `predicates_defined_on`, plus
/// `Self: Trait` predicates for traits.
@ -99,8 +96,9 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
| ItemKind::Struct(_, generics)
| ItemKind::Union(_, generics) => generics,
ItemKind::Trait(_, _, generics, ..) | ItemKind::TraitAlias(generics, _) => {
is_trait = Some(ty::TraitRef::identity(tcx, def_id.to_def_id()));
ItemKind::Trait(_, _, generics, self_bounds, ..)
| ItemKind::TraitAlias(generics, self_bounds) => {
is_trait = Some(self_bounds);
generics
}
ItemKind::OpaqueTy(OpaqueTy { generics, .. }) => generics,
@ -122,10 +120,14 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
// Below we'll consider the bounds on the type parameters (including `Self`)
// and the explicit where-clauses, but to get the full set of predicates
// on a trait we need to add in the supertrait bounds and bounds found on
// associated types.
if let Some(_trait_ref) = is_trait {
predicates.extend(tcx.implied_predicates_of(def_id).predicates.iter().cloned());
// on a trait we must also consider the bounds that follow the trait's name,
// like `trait Foo: A + B + C`.
if let Some(self_bounds) = is_trait {
predicates.extend(
icx.astconv()
.compute_bounds(tcx.types.self_param, self_bounds, OnlySelfBounds(false))
.predicates(),
);
}
// In default impls, we can assume that the self type implements
@ -225,7 +227,13 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
}
let mut bounds = Bounds::default();
icx.astconv().add_bounds(ty, bound_pred.bounds.iter(), &mut bounds, bound_vars);
icx.astconv().add_bounds(
ty,
bound_pred.bounds.iter(),
&mut bounds,
bound_vars,
OnlySelfBounds(false),
);
predicates.extend(bounds.predicates());
}
@ -608,7 +616,7 @@ pub(super) fn implied_predicates_with_filter(
let (superbounds, where_bounds_that_match) = match filter {
PredicateFilter::All => (
// Convert the bounds that follow the colon (or equal in trait aliases)
icx.astconv().compute_bounds(self_param_ty, bounds),
icx.astconv().compute_bounds(self_param_ty, bounds, OnlySelfBounds(false)),
// Also include all where clause bounds
icx.type_parameter_bounds_in_generics(
generics,
@ -620,7 +628,7 @@ pub(super) fn implied_predicates_with_filter(
),
PredicateFilter::SelfOnly => (
// Convert the bounds that follow the colon (or equal in trait aliases)
icx.astconv().compute_bounds(self_param_ty, bounds),
icx.astconv().compute_bounds(self_param_ty, bounds, OnlySelfBounds(true)),
// Include where clause bounds for `Self`
icx.type_parameter_bounds_in_generics(
generics,
@ -774,32 +782,35 @@ impl<'tcx> ItemCtxt<'tcx> {
only_self_bounds: OnlySelfBounds,
assoc_name: Option<Ident>,
) -> Vec<(ty::Predicate<'tcx>, Span)> {
ast_generics
.predicates
.iter()
.filter_map(|wp| match wp {
hir::WherePredicate::BoundPredicate(bp) => Some(bp),
_ => None,
})
.flat_map(|bp| {
let bt = if bp.is_param_bound(param_def_id.to_def_id()) {
Some(ty)
} else if !only_self_bounds.0 {
Some(self.to_ty(bp.bounded_ty))
} else {
None
};
let bvars = self.tcx.late_bound_vars(bp.hir_id);
let mut bounds = Bounds::default();
bp.bounds.iter().filter_map(move |b| bt.map(|bt| (bt, b, bvars))).filter(
|(_, b, _)| match assoc_name {
Some(assoc_name) => self.bound_defines_assoc_item(b, assoc_name),
None => true,
},
)
})
.flat_map(|(bt, b, bvars)| predicates_from_bound(self, bt, b, bvars))
.collect()
for predicate in ast_generics.predicates {
let hir::WherePredicate::BoundPredicate(predicate) = predicate else {
continue;
};
let bound_ty = if predicate.is_param_bound(param_def_id.to_def_id()) {
ty
} else if !only_self_bounds.0 {
self.to_ty(predicate.bounded_ty)
} else {
continue;
};
let bound_vars = self.tcx.late_bound_vars(predicate.hir_id);
self.astconv().add_bounds(
bound_ty,
predicate.bounds.iter().filter(|bound| {
assoc_name
.map_or(true, |assoc_name| self.bound_defines_assoc_item(bound, assoc_name))
}),
&mut bounds,
bound_vars,
only_self_bounds,
);
}
bounds.predicates().collect()
}
#[instrument(level = "trace", skip(self))]
@ -817,19 +828,3 @@ impl<'tcx> ItemCtxt<'tcx> {
}
}
}
/// Converts a specific `GenericBound` from the AST into a set of
/// predicates that apply to the self type. A vector is returned
/// because this can be anywhere from zero predicates (`T: ?Sized` adds no
/// predicates) to one (`T: Foo`) to many (`T: Bar<X = i32>` adds `T: Bar`
/// and `<T as Bar>::X == i32`).
fn predicates_from_bound<'tcx>(
astconv: &dyn AstConv<'tcx>,
param_ty: Ty<'tcx>,
bound: &'tcx hir::GenericBound<'tcx>,
bound_vars: &'tcx ty::List<ty::BoundVariableKind>,
) -> Vec<(ty::Predicate<'tcx>, Span)> {
let mut bounds = Bounds::default();
astconv.add_bounds(param_ty, [bound].into_iter(), &mut bounds, bound_vars);
bounds.predicates().collect()
}

8
compiler/rustc_hir_analysis/src/errors.rs
View file

@ -107,6 +107,14 @@ pub struct CopyImplOnNonAdt {
pub span: Span,
}
#[derive(Diagnostic)]
#[diag(hir_analysis_const_param_ty_impl_on_non_adt)]
pub struct ConstParamTyImplOnNonAdt {
#[primary_span]
#[label]
pub span: Span,
}
#[derive(Diagnostic)]
#[diag(hir_analysis_trait_object_declared_with_no_traits, code = "E0224")]
pub struct TraitObjectDeclaredWithNoTraits {

3
compiler/rustc_hir_analysis/src/lib.rs
View file

@ -116,7 +116,7 @@ use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode,
use std::ops::Not;
use astconv::AstConv;
use astconv::{AstConv, OnlySelfBounds};
use bounds::Bounds;
fluent_messages! { "../messages.ftl" }
@ -531,6 +531,7 @@ pub fn hir_trait_to_predicates<'tcx>(
self_ty,
&mut bounds,
true,
OnlySelfBounds(false),
);
bounds

8
compiler/rustc_lint/messages.ftl
View file

@ -50,6 +50,14 @@ lint_deprecated_lint_name =
lint_renamed_or_removed_lint = {$msg}
.suggestion = use the new name
lint_suspicious_double_ref_op =
using `.{$call}()` on a double reference, which returns `{$ty}` instead of {$op ->
*[should_not_happen] [{$op}]
[deref] dereferencing
[borrow] borrowing
[clone] cloning
} the inner type
lint_unknown_lint =
unknown lint: `{$name}`
.suggestion = did you mean

8
compiler/rustc_lint/src/lints.rs
View file

@ -1150,6 +1150,14 @@ pub struct NoopMethodCallDiag<'a> {
pub label: Span,
}
#[derive(LintDiagnostic)]
#[diag(lint_suspicious_double_ref_op)]
pub struct SuspiciousDoubleRefDiag<'a> {
pub call: Symbol,
pub ty: Ty<'a>,
pub op: &'static str,
}
// pass_by_value.rs
#[derive(LintDiagnostic)]
#[diag(lint_pass_by_value)]

81
compiler/rustc_lint/src/noop_method_call.rs
View file

@ -1,10 +1,11 @@
use crate::context::LintContext;
use crate::lints::NoopMethodCallDiag;
use crate::lints::{NoopMethodCallDiag, SuspiciousDoubleRefDiag};
use crate::LateContext;
use crate::LateLintPass;
use rustc_hir::def::DefKind;
use rustc_hir::{Expr, ExprKind};
use rustc_middle::ty;
use rustc_middle::ty::adjustment::Adjust;
use rustc_span::symbol::sym;
declare_lint! {
@ -35,14 +36,44 @@ declare_lint! {
"detects the use of well-known noop methods"
}
declare_lint_pass!(NoopMethodCall => [NOOP_METHOD_CALL]);
declare_lint! {
/// The `suspicious_double_ref_op` lint checks for usage of `.clone()`/`.borrow()`/`.deref()`
/// on an `&&T` when `T: !Deref/Borrow/Clone`, which means the call will return the inner `&T`,
/// instead of performing the operation on the underlying `T` and can be confusing.
///
/// ### Example
///
/// ```rust
/// # #![allow(unused)]
/// struct Foo;
/// let foo = &&Foo;
/// let clone: &Foo = foo.clone();
/// ```
///
/// {{produces}}
///
/// ### Explanation
///
/// Since `Foo` doesn't implement `Clone`, running `.clone()` only dereferences the double
/// reference, instead of cloning the inner type which should be what was intended.
pub SUSPICIOUS_DOUBLE_REF_OP,
Warn,
"suspicious call of trait method on `&&T`"
}
declare_lint_pass!(NoopMethodCall => [NOOP_METHOD_CALL, SUSPICIOUS_DOUBLE_REF_OP]);
impl<'tcx> LateLintPass<'tcx> for NoopMethodCall {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
// We only care about method calls.
let ExprKind::MethodCall(call, receiver, ..) = &expr.kind else {
return
let ExprKind::MethodCall(call, receiver, _, call_span) = &expr.kind else {
return;
};
if call_span.from_expansion() {
return;
}
// We only care about method calls corresponding to the `Clone`, `Deref` and `Borrow`
// traits and ignore any other method call.
let did = match cx.typeck_results().type_dependent_def(expr.hir_id) {
@ -70,25 +101,39 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall {
};
// (Re)check that it implements the noop diagnostic.
let Some(name) = cx.tcx.get_diagnostic_name(i.def_id()) else { return };
if !matches!(
name,
sym::noop_method_borrow | sym::noop_method_clone | sym::noop_method_deref
) {
return;
}
let op = match name {
sym::noop_method_borrow => "borrow",
sym::noop_method_clone => "clone",
sym::noop_method_deref => "deref",
_ => return,
};
let receiver_ty = cx.typeck_results().expr_ty(receiver);
let expr_ty = cx.typeck_results().expr_ty_adjusted(expr);
if receiver_ty != expr_ty {
// This lint will only trigger if the receiver type and resulting expression \
// type are the same, implying that the method call is unnecessary.
let arg_adjustments = cx.typeck_results().expr_adjustments(receiver);
// If there is any user defined auto-deref step, then we don't want to warn.
// https://github.com/rust-lang/rust-clippy/issues/9272
if arg_adjustments.iter().any(|adj| matches!(adj.kind, Adjust::Deref(Some(_)))) {
return;
}
let expr_span = expr.span;
let span = expr_span.with_lo(receiver.span.hi());
cx.emit_spanned_lint(
NOOP_METHOD_CALL,
span,
NoopMethodCallDiag { method: call.ident.name, receiver_ty, label: span },
);
if receiver_ty == expr_ty {
cx.emit_spanned_lint(
NOOP_METHOD_CALL,
span,
NoopMethodCallDiag { method: call.ident.name, receiver_ty, label: span },
);
} else {
cx.emit_spanned_lint(
SUSPICIOUS_DOUBLE_REF_OP,
span,
SuspiciousDoubleRefDiag { call: call.ident.name, ty: expr_ty, op },
)
}
}
}

1
compiler/rustc_span/src/symbol.rs
View file

@ -531,6 +531,7 @@ symbols! {
const_mut_refs,
const_panic,
const_panic_fmt,
const_param_ty,
const_precise_live_drops,
const_raw_ptr_deref,
const_raw_ptr_to_usize_cast,

101
compiler/rustc_trait_selection/src/traits/misc.rs
View file

@ -2,13 +2,14 @@
use crate::traits::{self, ObligationCause, ObligationCtxt};
use hir::LangItem;
use rustc_data_structures::fx::FxIndexSet;
use rustc_hir as hir;
use rustc_infer::infer::canonical::Canonical;
use rustc_infer::infer::{RegionResolutionError, TyCtxtInferExt};
use rustc_infer::traits::query::NoSolution;
use rustc_infer::{infer::outlives::env::OutlivesEnvironment, traits::FulfillmentError};
use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt, TypeVisitableExt};
use rustc_middle::ty::{self, AdtDef, GenericArg, List, ParamEnv, Ty, TyCtxt, TypeVisitableExt};
use rustc_span::DUMMY_SP;
use super::outlives_bounds::InferCtxtExt;
@ -19,6 +20,11 @@ pub enum CopyImplementationError<'tcx> {
HasDestructor,
}
pub enum ConstParamTyImplementationError<'tcx> {
InfrigingFields(Vec<(&'tcx ty::FieldDef, Ty<'tcx>, InfringingFieldsReason<'tcx>)>),
NotAnAdtOrBuiltinAllowed,
}
pub enum InfringingFieldsReason<'tcx> {
Fulfill(Vec<FulfillmentError<'tcx>>),
Regions(Vec<RegionResolutionError<'tcx>>),
@ -27,7 +33,10 @@ pub enum InfringingFieldsReason<'tcx> {
/// Checks that the fields of the type (an ADT) all implement copy.
///
/// If fields don't implement copy, return an error containing a list of
/// those violating fields. If it's not an ADT, returns `Err(NotAnAdt)`.
/// those violating fields.
///
/// If it's not an ADT, int ty, `bool`, float ty, `char`, raw pointer, `!`,
/// a reference or an array returns `Err(NotAnAdt)`.
pub fn type_allowed_to_implement_copy<'tcx>(
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
@ -47,12 +56,82 @@ pub fn type_allowed_to_implement_copy<'tcx>(
| ty::Ref(_, _, hir::Mutability::Not)
| ty::Array(..) => return Ok(()),
ty::Adt(adt, substs) => (adt, substs),
&ty::Adt(adt, substs) => (adt, substs),
_ => return Err(CopyImplementationError::NotAnAdt),
};
let copy_def_id = tcx.require_lang_item(hir::LangItem::Copy, Some(parent_cause.span));
all_fields_implement_trait(
tcx,
param_env,
self_type,
adt,
substs,
parent_cause,
hir::LangItem::Copy,
)
.map_err(CopyImplementationError::InfringingFields)?;
if adt.has_dtor(tcx) {
return Err(CopyImplementationError::HasDestructor);
}
Ok(())
}
/// Checks that the fields of the type (an ADT) all implement `ConstParamTy`.
///
/// If fields don't implement `ConstParamTy`, return an error containing a list of
/// those violating fields.
///
/// If it's not an ADT, int ty, `bool` or `char`, returns `Err(NotAnAdtOrBuiltinAllowed)`.
pub fn type_allowed_to_implement_const_param_ty<'tcx>(
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
self_type: Ty<'tcx>,
parent_cause: ObligationCause<'tcx>,
) -> Result<(), ConstParamTyImplementationError<'tcx>> {
let (adt, substs) = match self_type.kind() {
// `core` provides these impls.
ty::Uint(_)
| ty::Int(_)
| ty::Bool
| ty::Char
| ty::Str
| ty::Array(..)
| ty::Slice(_)
| ty::Ref(.., hir::Mutability::Not) => return Ok(()),
&ty::Adt(adt, substs) => (adt, substs),
_ => return Err(ConstParamTyImplementationError::NotAnAdtOrBuiltinAllowed),
};
all_fields_implement_trait(
tcx,
param_env,
self_type,
adt,
substs,
parent_cause,
hir::LangItem::ConstParamTy,
)
.map_err(ConstParamTyImplementationError::InfrigingFields)?;
Ok(())
}
/// Check that all fields of a given `adt` implement `lang_item` trait.
pub fn all_fields_implement_trait<'tcx>(
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
self_type: Ty<'tcx>,
adt: AdtDef<'tcx>,
substs: &'tcx List<GenericArg<'tcx>>,
parent_cause: ObligationCause<'tcx>,
lang_item: LangItem,
) -> Result<(), Vec<(&'tcx ty::FieldDef, Ty<'tcx>, InfringingFieldsReason<'tcx>)>> {
let trait_def_id = tcx.require_lang_item(lang_item, Some(parent_cause.span));
let mut infringing = Vec::new();
for variant in adt.variants() {
@ -93,7 +172,7 @@ pub fn type_allowed_to_implement_copy<'tcx>(
// between expected and found const-generic types. Don't report an
// additional copy error here, since it's not typically useful.
if !normalization_errors.is_empty() || ty.references_error() {
tcx.sess.delay_span_bug(field_span, format!("couldn't normalize struct field `{unnormalized_ty}` when checking Copy implementation"));
tcx.sess.delay_span_bug(field_span, format!("couldn't normalize struct field `{unnormalized_ty}` when checking {tr} implementation", tr = tcx.def_path_str(trait_def_id)));
continue;
}
@ -101,7 +180,7 @@ pub fn type_allowed_to_implement_copy<'tcx>(
ObligationCause::dummy_with_span(field_ty_span),
param_env,
ty,
copy_def_id,
trait_def_id,
);
let errors = ocx.select_all_or_error();
if !errors.is_empty() {
@ -124,15 +203,7 @@ pub fn type_allowed_to_implement_copy<'tcx>(
}
}
if !infringing.is_empty() {
return Err(CopyImplementationError::InfringingFields(infringing));
}
if adt.has_dtor(tcx) {
return Err(CopyImplementationError::HasDestructor);
}
Ok(())
if infringing.is_empty() { Ok(()) } else { Err(infringing) }
}
pub fn check_tys_might_be_eq<'tcx>(