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Auto merge of rust-lang#127936 - matthiaskrgr:rollup-ci0eg7k, r=matth…
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Rollup of 8 pull requests

Successful merges:

 - rust-lang#127418 (Wrap too long type name)
 - rust-lang#127594 (Fuchsia status code match arm)
 - rust-lang#127835 (Fix ICE in suggestion caused by `⩵` being recovered as `==`)
 - rust-lang#127858 (match lowering: Rename `MatchPair` to `MatchPairTree`)
 - rust-lang#127871 (Mention that type parameters are used recursively on bivariance error)
 - rust-lang#127913 (remove `debug-logging` default from tools profile)
 - rust-lang#127925 (Remove tag field from `Relation`s)
 - rust-lang#127929 (Use more accurate span for `addr_of!` suggestion)

r? `@ghost`
`@rustbot` modify labels: rollup
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bors committed Jul 19, 2024
2 parents 5affbb1 + d1250bc commit 1a77c99
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Showing 63 changed files with 447 additions and 247 deletions.
4 changes: 0 additions & 4 deletions compiler/rustc_borrowck/src/type_check/relate_tys.rs
Original file line number Diff line number Diff line change
Expand Up @@ -313,10 +313,6 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
self.type_checker.infcx.tcx
}

fn tag(&self) -> &'static str {
"nll::subtype"
}

#[instrument(skip(self, info), level = "trace", ret)]
fn relate_with_variance<T: Relate<TyCtxt<'tcx>>>(
&mut self,
Expand Down
6 changes: 6 additions & 0 deletions compiler/rustc_hir_analysis/messages.ftl
Original file line number Diff line number Diff line change
Expand Up @@ -382,6 +382,10 @@ hir_analysis_placeholder_not_allowed_item_signatures = the placeholder `_` is no
hir_analysis_precise_capture_self_alias = `Self` can't be captured in `use<...>` precise captures list, since it is an alias
.label = `Self` is not a generic argument, but an alias to the type of the {$what}
hir_analysis_recursive_generic_parameter = {$param_def_kind} `{$param_name}` is only used recursively
.label = {$param_def_kind} must be used non-recursively in the definition
.note = all type parameters must be used in a non-recursive way in order to constrain their variance
hir_analysis_redundant_lifetime_args = unnecessary lifetime parameter `{$victim}`
.note = you can use the `{$candidate}` lifetime directly, in place of `{$victim}`
Expand Down Expand Up @@ -549,6 +553,8 @@ hir_analysis_unused_generic_parameter =
{$param_def_kind} `{$param_name}` is never used
.label = unused {$param_def_kind}
.const_param_help = if you intended `{$param_name}` to be a const parameter, use `const {$param_name}: /* Type */` instead
.usage_spans = `{$param_name}` is named here, but is likely unused in the containing type
hir_analysis_unused_generic_parameter_adt_help =
consider removing `{$param_name}`, referring to it in a field, or using a marker such as `{$phantom_data}`
hir_analysis_unused_generic_parameter_adt_no_phantom_data_help =
Expand Down
1 change: 1 addition & 0 deletions compiler/rustc_hir_analysis/src/check/check.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1572,6 +1572,7 @@ fn check_type_alias_type_params_are_used<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalD
param_name,
param_def_kind: tcx.def_descr(param.def_id),
help: errors::UnusedGenericParameterHelp::TyAlias { param_name },
usage_spans: vec![],
const_param_help,
});
diag.code(E0091);
Expand Down
35 changes: 22 additions & 13 deletions compiler/rustc_hir_analysis/src/check/errs.rs
Original file line number Diff line number Diff line change
@@ -1,5 +1,4 @@
use rustc_hir as hir;
use rustc_hir_pretty::qpath_to_string;
use rustc_lint_defs::builtin::STATIC_MUT_REFS;
use rustc_middle::ty::{Mutability, TyCtxt};
use rustc_span::Span;
Expand All @@ -12,9 +11,17 @@ pub fn maybe_expr_static_mut(tcx: TyCtxt<'_>, expr: hir::Expr<'_>) {
let hir_id = expr.hir_id;
if let hir::ExprKind::AddrOf(borrow_kind, m, expr) = expr.kind
&& matches!(borrow_kind, hir::BorrowKind::Ref)
&& let Some(var) = path_if_static_mut(tcx, expr)
&& path_if_static_mut(expr)
{
handle_static_mut_ref(tcx, span, var, span.edition().at_least_rust_2024(), m, hir_id);
handle_static_mut_ref(
tcx,
span,
span.with_hi(expr.span.lo()),
span.shrink_to_hi(),
span.edition().at_least_rust_2024(),
m,
hir_id,
);
}
}

Expand All @@ -24,51 +31,53 @@ pub fn maybe_stmt_static_mut(tcx: TyCtxt<'_>, stmt: hir::Stmt<'_>) {
&& let hir::PatKind::Binding(ba, _, _, _) = loc.pat.kind
&& let hir::ByRef::Yes(rmutbl) = ba.0
&& let Some(init) = loc.init
&& let Some(var) = path_if_static_mut(tcx, init)
&& path_if_static_mut(init)
{
handle_static_mut_ref(
tcx,
init.span,
var,
init.span.shrink_to_lo(),
init.span.shrink_to_hi(),
loc.span.edition().at_least_rust_2024(),
rmutbl,
stmt.hir_id,
);
}
}

fn path_if_static_mut(tcx: TyCtxt<'_>, expr: &hir::Expr<'_>) -> Option<String> {
fn path_if_static_mut(expr: &hir::Expr<'_>) -> bool {
if let hir::ExprKind::Path(qpath) = expr.kind
&& let hir::QPath::Resolved(_, path) = qpath
&& let hir::def::Res::Def(def_kind, _) = path.res
&& let hir::def::DefKind::Static { safety: _, mutability: Mutability::Mut, nested: false } =
def_kind
{
return Some(qpath_to_string(&tcx, &qpath));
return true;
}
None
false
}

fn handle_static_mut_ref(
tcx: TyCtxt<'_>,
span: Span,
var: String,
lo: Span,
hi: Span,
e2024: bool,
mutable: Mutability,
hir_id: hir::HirId,
) {
if e2024 {
let (sugg, shared) = if mutable == Mutability::Mut {
(errors::StaticMutRefSugg::Mut { span, var }, "mutable")
(errors::MutRefSugg::Mut { lo, hi }, "mutable")
} else {
(errors::StaticMutRefSugg::Shared { span, var }, "shared")
(errors::MutRefSugg::Shared { lo, hi }, "shared")
};
tcx.dcx().emit_err(errors::StaticMutRef { span, sugg, shared });
} else {
let (sugg, shared) = if mutable == Mutability::Mut {
(errors::RefOfMutStaticSugg::Mut { span, var }, "mutable")
(errors::MutRefSugg::Mut { lo, hi }, "mutable")
} else {
(errors::RefOfMutStaticSugg::Shared { span, var }, "shared")
(errors::MutRefSugg::Shared { lo, hi }, "shared")
};
tcx.emit_node_span_lint(
STATIC_MUT_REFS,
Expand Down
133 changes: 124 additions & 9 deletions compiler/rustc_hir_analysis/src/check/wfcheck.rs
Original file line number Diff line number Diff line change
Expand Up @@ -4,12 +4,12 @@ use crate::constrained_generic_params::{identify_constrained_generic_params, Par
use crate::errors;
use crate::fluent_generated as fluent;

use hir::intravisit::Visitor;
use hir::intravisit::{self, Visitor};
use rustc_ast as ast;
use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
use rustc_errors::{codes::*, pluralize, struct_span_code_err, Applicability, ErrorGuaranteed};
use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def::{DefKind, Res};
use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
use rustc_hir::lang_items::LangItem;
use rustc_hir::ItemKind;
Expand Down Expand Up @@ -1799,7 +1799,7 @@ fn receiver_is_implemented<'tcx>(

fn check_variances_for_type_defn<'tcx>(
tcx: TyCtxt<'tcx>,
item: &hir::Item<'tcx>,
item: &'tcx hir::Item<'tcx>,
hir_generics: &hir::Generics<'tcx>,
) {
let identity_args = ty::GenericArgs::identity_for_item(tcx, item.owner_id);
Expand Down Expand Up @@ -1886,21 +1886,21 @@ fn check_variances_for_type_defn<'tcx>(
hir::ParamName::Error => {}
_ => {
let has_explicit_bounds = explicitly_bounded_params.contains(&parameter);
report_bivariance(tcx, hir_param, has_explicit_bounds, item.kind);
report_bivariance(tcx, hir_param, has_explicit_bounds, item);
}
}
}
}

fn report_bivariance(
tcx: TyCtxt<'_>,
param: &rustc_hir::GenericParam<'_>,
fn report_bivariance<'tcx>(
tcx: TyCtxt<'tcx>,
param: &'tcx hir::GenericParam<'tcx>,
has_explicit_bounds: bool,
item_kind: ItemKind<'_>,
item: &'tcx hir::Item<'tcx>,
) -> ErrorGuaranteed {
let param_name = param.name.ident();

let help = match item_kind {
let help = match item.kind {
ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) => {
if let Some(def_id) = tcx.lang_items().phantom_data() {
errors::UnusedGenericParameterHelp::Adt {
Expand All @@ -1915,6 +1915,49 @@ fn report_bivariance(
item_kind => bug!("report_bivariance: unexpected item kind: {item_kind:?}"),
};

let mut usage_spans = vec![];
intravisit::walk_item(
&mut CollectUsageSpans { spans: &mut usage_spans, param_def_id: param.def_id.to_def_id() },
item,
);

if !usage_spans.is_empty() {
// First, check if the ADT is (probably) cyclical. We say probably here, since
// we're not actually looking into substitutions, just walking through fields.
// And we only recurse into the fields of ADTs, and not the hidden types of
// opaques or anything else fancy.
let item_def_id = item.owner_id.to_def_id();
let is_probably_cyclical = if matches!(
tcx.def_kind(item_def_id),
DefKind::Struct | DefKind::Union | DefKind::Enum
) {
IsProbablyCyclical { tcx, adt_def_id: item_def_id, seen: Default::default() }
.visit_all_fields(tcx.adt_def(item_def_id))
.is_break()
} else {
false
};
// If the ADT is cyclical, then if at least one usage of the type parameter or
// the `Self` alias is present in the, then it's probably a cyclical struct, and
// we should call those parameter usages recursive rather than just saying they're
// unused...
//
// We currently report *all* of the parameter usages, since computing the exact
// subset is very involved, and the fact we're mentioning recursion at all is
// likely to guide the user in the right direction.
if is_probably_cyclical {
let diag = tcx.dcx().create_err(errors::RecursiveGenericParameter {
spans: usage_spans,
param_span: param.span,
param_name,
param_def_kind: tcx.def_descr(param.def_id.to_def_id()),
help,
note: (),
});
return diag.emit();
}
}

let const_param_help =
matches!(param.kind, hir::GenericParamKind::Type { .. } if !has_explicit_bounds)
.then_some(());
Expand All @@ -1923,13 +1966,85 @@ fn report_bivariance(
span: param.span,
param_name,
param_def_kind: tcx.def_descr(param.def_id.to_def_id()),
usage_spans,
help,
const_param_help,
});
diag.code(E0392);
diag.emit()
}

/// Detects cases where an ADT is trivially cyclical -- we want to detect this so
/// /we only mention that its parameters are used cyclically if the ADT is truly
/// cyclical.
///
/// Notably, we don't consider substitutions here, so this may have false positives.
struct IsProbablyCyclical<'tcx> {
tcx: TyCtxt<'tcx>,
adt_def_id: DefId,
seen: FxHashSet<DefId>,
}

impl<'tcx> IsProbablyCyclical<'tcx> {
fn visit_all_fields(&mut self, adt_def: ty::AdtDef<'tcx>) -> ControlFlow<(), ()> {
for field in adt_def.all_fields() {
self.tcx.type_of(field.did).instantiate_identity().visit_with(self)?;
}

ControlFlow::Continue(())
}
}

impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for IsProbablyCyclical<'tcx> {
type Result = ControlFlow<(), ()>;

fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<(), ()> {
if let Some(adt_def) = t.ty_adt_def() {
if adt_def.did() == self.adt_def_id {
return ControlFlow::Break(());
}

if self.seen.insert(adt_def.did()) {
self.visit_all_fields(adt_def)?;
}
}

t.super_visit_with(self)
}
}

/// Collect usages of the `param_def_id` and `Res::SelfTyAlias` in the HIR.
///
/// This is used to report places where the user has used parameters in a
/// non-variance-constraining way for better bivariance errors.
struct CollectUsageSpans<'a> {
spans: &'a mut Vec<Span>,
param_def_id: DefId,
}

impl<'tcx> Visitor<'tcx> for CollectUsageSpans<'_> {
type Result = ();

fn visit_generics(&mut self, _g: &'tcx rustc_hir::Generics<'tcx>) -> Self::Result {
// Skip the generics. We only care about fields, not where clause/param bounds.
}

fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) -> Self::Result {
if let hir::TyKind::Path(hir::QPath::Resolved(None, qpath)) = t.kind {
if let Res::Def(DefKind::TyParam, def_id) = qpath.res
&& def_id == self.param_def_id
{
self.spans.push(t.span);
return;
} else if let Res::SelfTyAlias { .. } = qpath.res {
self.spans.push(t.span);
return;
}
}
intravisit::walk_ty(self, t);
}
}

impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
/// Feature gates RFC 2056 -- trivial bounds, checking for global bounds that
/// aren't true.
Expand Down
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