Auto merge of #87140 - camsteffen:pat-slice-refs, r=oli-obk

Remove refs from Pat slices

Changes `PatKind::Or(&'hir [&'hir Pat<'hir>])` to `PatKind::Or(&'hir [Pat<'hir>])` and others. This is more consistent with `ExprKind`, saves a little memory, and is a little easier to use.
This commit is contained in:
bors 2021-07-16 13:35:48 +00:00
commit 2119976c49
12 changed files with 85 additions and 68 deletions

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@ -1067,6 +1067,15 @@ fn destructure_assign(
eq_sign_span: Span,
assignments: &mut Vec<hir::Stmt<'hir>>,
) -> &'hir hir::Pat<'hir> {
self.arena.alloc(self.destructure_assign_mut(lhs, eq_sign_span, assignments))
}
fn destructure_assign_mut(
&mut self,
lhs: &Expr,
eq_sign_span: Span,
assignments: &mut Vec<hir::Stmt<'hir>>,
) -> hir::Pat<'hir> {
match &lhs.kind {
// Underscore pattern.
ExprKind::Underscore => {
@ -1080,7 +1089,7 @@ fn destructure_assign(
let (before, after) = pats.split_at(i);
hir::PatKind::Slice(
before,
Some(self.pat_without_dbm(span, hir::PatKind::Wild)),
Some(self.arena.alloc(self.pat_without_dbm(span, hir::PatKind::Wild))),
after,
)
} else {
@ -1165,14 +1174,14 @@ fn destructure_assign(
let tuple_pat = hir::PatKind::Tuple(&[], Some(0));
return self.pat_without_dbm(lhs.span, tuple_pat);
} else {
return self.destructure_assign(e, eq_sign_span, assignments);
return self.destructure_assign_mut(e, eq_sign_span, assignments);
}
}
_ => {}
}
// Treat all other cases as normal lvalue.
let ident = Ident::new(sym::lhs, lhs.span);
let (pat, binding) = self.pat_ident(lhs.span, ident);
let (pat, binding) = self.pat_ident_mut(lhs.span, ident);
let ident = self.expr_ident(lhs.span, ident, binding);
let assign = hir::ExprKind::Assign(self.lower_expr(lhs), ident, eq_sign_span);
let expr = self.expr(lhs.span, assign, ThinVec::new());
@ -1191,7 +1200,7 @@ fn destructure_sequence(
ctx: &str,
eq_sign_span: Span,
assignments: &mut Vec<hir::Stmt<'hir>>,
) -> (&'hir [&'hir hir::Pat<'hir>], Option<(usize, Span)>) {
) -> (&'hir [hir::Pat<'hir>], Option<(usize, Span)>) {
let mut rest = None;
let elements =
self.arena.alloc_from_iter(elements.iter().enumerate().filter_map(|(i, e)| {
@ -1204,7 +1213,7 @@ fn destructure_sequence(
}
None
} else {
Some(self.destructure_assign(e, eq_sign_span, assignments))
Some(self.destructure_assign_mut(e, eq_sign_span, assignments))
}
}));
(elements, rest)

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@ -2577,21 +2577,35 @@ fn pat_ident(&mut self, span: Span, ident: Ident) -> (&'hir hir::Pat<'hir>, hir:
self.pat_ident_binding_mode(span, ident, hir::BindingAnnotation::Unannotated)
}
fn pat_ident_mut(&mut self, span: Span, ident: Ident) -> (hir::Pat<'hir>, hir::HirId) {
self.pat_ident_binding_mode_mut(span, ident, hir::BindingAnnotation::Unannotated)
}
fn pat_ident_binding_mode(
&mut self,
span: Span,
ident: Ident,
bm: hir::BindingAnnotation,
) -> (&'hir hir::Pat<'hir>, hir::HirId) {
let (pat, hir_id) = self.pat_ident_binding_mode_mut(span, ident, bm);
(self.arena.alloc(pat), hir_id)
}
fn pat_ident_binding_mode_mut(
&mut self,
span: Span,
ident: Ident,
bm: hir::BindingAnnotation,
) -> (hir::Pat<'hir>, hir::HirId) {
let hir_id = self.next_id();
(
self.arena.alloc(hir::Pat {
hir::Pat {
hir_id,
kind: hir::PatKind::Binding(bm, hir_id, ident.with_span_pos(span), None),
span,
default_binding_modes: true,
}),
},
hir_id,
)
}
@ -2609,13 +2623,8 @@ fn pat(&mut self, span: Span, kind: hir::PatKind<'hir>) -> &'hir hir::Pat<'hir>
})
}
fn pat_without_dbm(&mut self, span: Span, kind: hir::PatKind<'hir>) -> &'hir hir::Pat<'hir> {
self.arena.alloc(hir::Pat {
hir_id: self.next_id(),
kind,
span,
default_binding_modes: false,
})
fn pat_without_dbm(&mut self, span: Span, kind: hir::PatKind<'hir>) -> hir::Pat<'hir> {
hir::Pat { hir_id: self.next_id(), kind, span, default_binding_modes: false }
}
fn ty_path(

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@ -10,7 +10,11 @@
use rustc_span::{source_map::Spanned, Span};
impl<'a, 'hir> LoweringContext<'a, 'hir> {
crate fn lower_pat(&mut self, mut pattern: &Pat) -> &'hir hir::Pat<'hir> {
crate fn lower_pat(&mut self, pattern: &Pat) -> &'hir hir::Pat<'hir> {
self.arena.alloc(self.lower_pat_mut(pattern))
}
crate fn lower_pat_mut(&mut self, mut pattern: &Pat) -> hir::Pat<'hir> {
ensure_sufficient_stack(|| {
// loop here to avoid recursion
let node = loop {
@ -34,7 +38,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
}
PatKind::Or(ref pats) => {
break hir::PatKind::Or(
self.arena.alloc_from_iter(pats.iter().map(|x| self.lower_pat(x))),
self.arena.alloc_from_iter(pats.iter().map(|x| self.lower_pat_mut(x))),
);
}
PatKind::Path(ref qself, ref path) => {
@ -101,7 +105,7 @@ fn lower_pat_tuple(
&mut self,
pats: &[P<Pat>],
ctx: &str,
) -> (&'hir [&'hir hir::Pat<'hir>], Option<usize>) {
) -> (&'hir [hir::Pat<'hir>], Option<usize>) {
let mut elems = Vec::with_capacity(pats.len());
let mut rest = None;
@ -140,7 +144,7 @@ fn lower_pat_tuple(
}
// It was not a sub-tuple pattern so lower it normally.
elems.push(self.lower_pat(pat));
elems.push(self.lower_pat_mut(pat));
}
for (_, pat) in iter {
@ -149,7 +153,7 @@ fn lower_pat_tuple(
// ...but there was one again, so error.
self.ban_extra_rest_pat(pat.span, rest.unwrap().1, ctx);
} else {
elems.push(self.lower_pat(pat));
elems.push(self.lower_pat_mut(pat));
}
}
@ -189,11 +193,11 @@ fn lower_pat_slice(&mut self, pats: &[P<Pat>]) -> hir::PatKind<'hir> {
// Record, lower it to `$binding_mode $ident @ _`, and stop here.
PatKind::Ident(ref bm, ident, Some(ref sub)) if sub.is_rest() => {
prev_rest_span = Some(sub.span);
slice = Some(lower_rest_sub(self, pat, bm, ident, sub));
slice = Some(self.arena.alloc(lower_rest_sub(self, pat, bm, ident, sub)));
break;
}
// It was not a subslice pattern so lower it normally.
_ => before.push(self.lower_pat(pat)),
_ => before.push(self.lower_pat_mut(pat)),
}
}
@ -214,7 +218,7 @@ fn lower_pat_slice(&mut self, pats: &[P<Pat>]) -> hir::PatKind<'hir> {
self.ban_extra_rest_pat(rest_span, prev_rest_span.unwrap(), "slice");
} else {
// Lower the pattern normally.
after.push(self.lower_pat(pat));
after.push(self.lower_pat_mut(pat));
}
}
@ -268,17 +272,17 @@ fn lower_binding_mode(&mut self, b: &BindingMode) -> hir::BindingAnnotation {
}
fn pat_wild_with_node_id_of(&mut self, p: &Pat) -> &'hir hir::Pat<'hir> {
self.pat_with_node_id_of(p, hir::PatKind::Wild)
self.arena.alloc(self.pat_with_node_id_of(p, hir::PatKind::Wild))
}
/// Construct a `Pat` with the `HirId` of `p.id` lowered.
fn pat_with_node_id_of(&mut self, p: &Pat, kind: hir::PatKind<'hir>) -> &'hir hir::Pat<'hir> {
self.arena.alloc(hir::Pat {
fn pat_with_node_id_of(&mut self, p: &Pat, kind: hir::PatKind<'hir>) -> hir::Pat<'hir> {
hir::Pat {
hir_id: self.lower_node_id(p.id),
kind,
span: p.span,
default_binding_modes: true,
})
}
}
/// Emit a friendly error for extra `..` patterns in a tuple/tuple struct/slice pattern.

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@ -808,13 +808,13 @@ fn walk_short_(&self, it: &mut impl FnMut(&Pat<'hir>) -> bool) -> bool {
}
use PatKind::*;
match &self.kind {
match self.kind {
Wild | Lit(_) | Range(..) | Binding(.., None) | Path(_) => true,
Box(s) | Ref(s, _) | Binding(.., Some(s)) => s.walk_short_(it),
Struct(_, fields, _) => fields.iter().all(|field| field.pat.walk_short_(it)),
TupleStruct(_, s, _) | Tuple(s, _) | Or(s) => s.iter().all(|p| p.walk_short_(it)),
Slice(before, slice, after) => {
before.iter().chain(slice.iter()).chain(after.iter()).all(|p| p.walk_short_(it))
before.iter().chain(slice).chain(after.iter()).all(|p| p.walk_short_(it))
}
}
}
@ -836,13 +836,13 @@ fn walk_(&self, it: &mut impl FnMut(&Pat<'hir>) -> bool) {
}
use PatKind::*;
match &self.kind {
match self.kind {
Wild | Lit(_) | Range(..) | Binding(.., None) | Path(_) => {}
Box(s) | Ref(s, _) | Binding(.., Some(s)) => s.walk_(it),
Struct(_, fields, _) => fields.iter().for_each(|field| field.pat.walk_(it)),
TupleStruct(_, s, _) | Tuple(s, _) | Or(s) => s.iter().for_each(|p| p.walk_(it)),
Slice(before, slice, after) => {
before.iter().chain(slice.iter()).chain(after.iter()).for_each(|p| p.walk_(it))
before.iter().chain(slice).chain(after.iter()).for_each(|p| p.walk_(it))
}
}
}
@ -940,11 +940,11 @@ pub enum PatKind<'hir> {
/// A tuple struct/variant pattern `Variant(x, y, .., z)`.
/// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
/// `0 <= position <= subpats.len()`
TupleStruct(QPath<'hir>, &'hir [&'hir Pat<'hir>], Option<usize>),
TupleStruct(QPath<'hir>, &'hir [Pat<'hir>], Option<usize>),
/// An or-pattern `A | B | C`.
/// Invariant: `pats.len() >= 2`.
Or(&'hir [&'hir Pat<'hir>]),
Or(&'hir [Pat<'hir>]),
/// A path pattern for an unit struct/variant or a (maybe-associated) constant.
Path(QPath<'hir>),
@ -952,7 +952,7 @@ pub enum PatKind<'hir> {
/// A tuple pattern (e.g., `(a, b)`).
/// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
/// `0 <= position <= subpats.len()`
Tuple(&'hir [&'hir Pat<'hir>], Option<usize>),
Tuple(&'hir [Pat<'hir>], Option<usize>),
/// A `box` pattern.
Box(&'hir Pat<'hir>),
@ -975,7 +975,7 @@ pub enum PatKind<'hir> {
/// ```
/// PatKind::Slice([Binding(a), Binding(b)], Some(Wild), [Binding(c), Binding(d)])
/// ```
Slice(&'hir [&'hir Pat<'hir>], Option<&'hir Pat<'hir>>, &'hir [&'hir Pat<'hir>]),
Slice(&'hir [Pat<'hir>], Option<&'hir Pat<'hir>>, &'hir [Pat<'hir>]),
}
#[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]

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@ -325,7 +325,7 @@ fn lower_pattern_unadjusted(&mut self, pat: &'tcx hir::Pat<'tcx>) -> Pat<'tcx> {
fn lower_tuple_subpats(
&mut self,
pats: &'tcx [&'tcx hir::Pat<'tcx>],
pats: &'tcx [hir::Pat<'tcx>],
expected_len: usize,
gap_pos: Option<usize>,
) -> Vec<FieldPat<'tcx>> {
@ -338,7 +338,7 @@ fn lower_tuple_subpats(
.collect()
}
fn lower_patterns(&mut self, pats: &'tcx [&'tcx hir::Pat<'tcx>]) -> Vec<Pat<'tcx>> {
fn lower_patterns(&mut self, pats: &'tcx [hir::Pat<'tcx>]) -> Vec<Pat<'tcx>> {
pats.iter().map(|p| self.lower_pattern(p)).collect()
}
@ -350,9 +350,9 @@ fn slice_or_array_pattern(
&mut self,
span: Span,
ty: Ty<'tcx>,
prefix: &'tcx [&'tcx hir::Pat<'tcx>],
prefix: &'tcx [hir::Pat<'tcx>],
slice: &'tcx Option<&'tcx hir::Pat<'tcx>>,
suffix: &'tcx [&'tcx hir::Pat<'tcx>],
suffix: &'tcx [hir::Pat<'tcx>],
) -> PatKind<'tcx> {
let prefix = self.lower_patterns(prefix);
let slice = self.lower_opt_pattern(slice);

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@ -864,7 +864,7 @@ fn check_pat_tuple_struct(
&self,
pat: &'tcx Pat<'tcx>,
qpath: &'tcx hir::QPath<'tcx>,
subpats: &'tcx [&'tcx Pat<'tcx>],
subpats: &'tcx [Pat<'tcx>],
ddpos: Option<usize>,
expected: Ty<'tcx>,
def_bm: BindingMode,
@ -982,7 +982,7 @@ fn e0023(
pat_span: Span,
res: Res,
qpath: &hir::QPath<'_>,
subpats: &'tcx [&'tcx Pat<'tcx>],
subpats: &'tcx [Pat<'tcx>],
fields: &'tcx [ty::FieldDef],
expected: Ty<'tcx>,
had_err: bool,
@ -1112,7 +1112,7 @@ fn e0023(
fn check_pat_tuple(
&self,
span: Span,
elements: &'tcx [&'tcx Pat<'tcx>],
elements: &'tcx [Pat<'tcx>],
ddpos: Option<usize>,
expected: Ty<'tcx>,
def_bm: BindingMode,
@ -1746,9 +1746,9 @@ fn new_ref_ty(&self, span: Span, mutbl: hir::Mutability, ty: Ty<'tcx>) -> Ty<'tc
fn check_pat_slice(
&self,
span: Span,
before: &'tcx [&'tcx Pat<'tcx>],
before: &'tcx [Pat<'tcx>],
slice: Option<&'tcx Pat<'tcx>>,
after: &'tcx [&'tcx Pat<'tcx>],
after: &'tcx [Pat<'tcx>],
expected: Ty<'tcx>,
def_bm: BindingMode,
ti: TopInfo<'tcx>,

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@ -260,17 +260,12 @@ pub(super) fn external_path(
PatKind::Wild | PatKind::Struct(..) => return kw::Underscore,
PatKind::Binding(_, _, ident, _) => return ident.name,
PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
PatKind::Or(ref pats) => pats
.iter()
.map(|p| name_from_pat(&**p).to_string())
.collect::<Vec<String>>()
.join(" | "),
PatKind::Or(ref pats) => {
pats.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(" | ")
}
PatKind::Tuple(ref elts, _) => format!(
"({})",
elts.iter()
.map(|p| name_from_pat(&**p).to_string())
.collect::<Vec<String>>()
.join(", ")
elts.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(", ")
),
PatKind::Box(ref p) => return name_from_pat(&**p),
PatKind::Ref(ref p, _) => return name_from_pat(&**p),
@ -282,9 +277,9 @@ pub(super) fn external_path(
}
PatKind::Range(..) => return kw::Underscore,
PatKind::Slice(ref begin, ref mid, ref end) => {
let begin = begin.iter().map(|p| name_from_pat(&**p).to_string());
let begin = begin.iter().map(|p| name_from_pat(p).to_string());
let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
let end = end.iter().map(|p| name_from_pat(&**p).to_string());
let end = end.iter().map(|p| name_from_pat(p).to_string());
format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
}
})

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@ -61,13 +61,13 @@ fn applicable_or_arm<'a>(cx: &LateContext<'_>, arms: &'a [Arm<'a>]) -> Option<&'
if let Some((idx, or_arm)) = arms.iter().enumerate().find(|(_, arm)| {
match arm.pat.kind {
PatKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
PatKind::TupleStruct(ref qpath, &[pat], _) =>
PatKind::TupleStruct(ref qpath, [pat], _) =>
matches!(pat.kind, PatKind::Wild) && is_lang_ctor(cx, qpath, ResultErr),
_ => false,
}
});
let unwrap_arm = &arms[1 - idx];
if let PatKind::TupleStruct(ref qpath, &[unwrap_pat], _) = unwrap_arm.pat.kind;
if let PatKind::TupleStruct(ref qpath, [unwrap_pat], _) = unwrap_arm.pat.kind;
if is_lang_ctor(cx, qpath, OptionSome) || is_lang_ctor(cx, qpath, ResultOk);
if let PatKind::Binding(_, binding_hir_id, ..) = unwrap_pat.kind;
if path_to_local_id(unwrap_arm.body, binding_hir_id);

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@ -625,7 +625,7 @@ fn check_local(&mut self, cx: &LateContext<'tcx>, local: &'tcx Local<'_>) {
if let PatKind::TupleStruct(
QPath::Resolved(None, variant_name), args, _) = arms[0].pat.kind;
if args.len() == 1;
if let PatKind::Binding(_, arg, ..) = strip_pat_refs(args[0]).kind;
if let PatKind::Binding(_, arg, ..) = strip_pat_refs(&args[0]).kind;
let body = remove_blocks(arms[0].body);
if path_to_local_id(body, arg);

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@ -132,7 +132,7 @@ fn detect_option_if_let_else<'tcx>(
if !is_else_clause(cx.tcx, expr);
if arms.len() == 2;
if !is_result_ok(cx, cond_expr); // Don't lint on Result::ok because a different lint does it already
if let PatKind::TupleStruct(struct_qpath, &[inner_pat], _) = &arms[0].pat.kind;
if let PatKind::TupleStruct(struct_qpath, [inner_pat], _) = &arms[0].pat.kind;
if is_lang_ctor(cx, struct_qpath, OptionSome);
if let PatKind::Binding(bind_annotation, _, id, _) = &inner_pat.kind;
if !contains_return_break_continue_macro(arms[0].body);

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@ -258,7 +258,7 @@ fn get_variant<'a>(adt_def: &'a AdtDef, qpath: &QPath<'_>) -> Option<&'a Variant
fn find_first_mismatch_in_tuple<'tcx, I>(
cx: &LateContext<'tcx>,
pats: &[&Pat<'_>],
pats: &[Pat<'_>],
ty_iter_src: I,
) -> Option<(Span, Mutability, Level)>
where

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@ -255,7 +255,7 @@ pub fn in_macro(span: Span) -> bool {
}
/// Checks if given pattern is a wildcard (`_`)
pub fn is_wild<'tcx>(pat: &impl std::ops::Deref<Target = Pat<'tcx>>) -> bool {
pub fn is_wild(pat: &Pat<'_>) -> bool {
matches!(pat.kind, PatKind::Wild)
}
@ -1023,8 +1023,8 @@ fn is_enum_variant(cx: &LateContext<'_>, qpath: &QPath<'_>, id: HirId) -> bool {
)
}
fn are_refutable<'a, I: Iterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, mut i: I) -> bool {
i.any(|pat| is_refutable(cx, pat))
fn are_refutable<'a, I: IntoIterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, i: I) -> bool {
i.into_iter().any(|pat| is_refutable(cx, pat))
}
match pat.kind {
@ -1035,23 +1035,23 @@ fn are_refutable<'a, I: Iterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, mut
PatKind::Path(ref qpath) => is_enum_variant(cx, qpath, pat.hir_id),
PatKind::Or(pats) => {
// TODO: should be the honest check, that pats is exhaustive set
are_refutable(cx, pats.iter().map(|pat| &**pat))
are_refutable(cx, pats)
},
PatKind::Tuple(pats, _) => are_refutable(cx, pats.iter().map(|pat| &**pat)),
PatKind::Tuple(pats, _) => are_refutable(cx, pats),
PatKind::Struct(ref qpath, fields, _) => {
is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| &*field.pat))
},
PatKind::TupleStruct(ref qpath, pats, _) => {
is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats.iter().map(|pat| &**pat))
is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats)
},
PatKind::Slice(head, ref middle, tail) => {
PatKind::Slice(head, middle, tail) => {
match &cx.typeck_results().node_type(pat.hir_id).kind() {
rustc_ty::Slice(..) => {
// [..] is the only irrefutable slice pattern.
!head.is_empty() || middle.is_none() || !tail.is_empty()
},
rustc_ty::Array(..) => {
are_refutable(cx, head.iter().chain(middle).chain(tail.iter()).map(|pat| &**pat))
are_refutable(cx, head.iter().chain(middle).chain(tail.iter()))
},
_ => {
// unreachable!()
@ -1066,7 +1066,7 @@ fn are_refutable<'a, I: Iterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, mut
/// the function once on the given pattern.
pub fn recurse_or_patterns<'tcx, F: FnMut(&'tcx Pat<'tcx>)>(pat: &'tcx Pat<'tcx>, mut f: F) {
if let PatKind::Or(pats) = pat.kind {
pats.iter().copied().for_each(f);
pats.iter().for_each(f);
} else {
f(pat);
}