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Remove print::Pat entirely, replacing it with String
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@Zalathar @workingjubilee
Zalathar authored and workingjubilee committed Aug 16, 2024
1 parent c2c496b commit b7a4532
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Showing 2 changed files with 35 additions and 69 deletions.
70 changes: 28 additions & 42 deletions compiler/rustc_pattern_analysis/src/rustc.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -774,17 +774,16 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
}
}

/// Convert to a [`print::Pat`] for diagnostic purposes.
fn hoist_pat_range(&self, range: &IntRange, ty: RevealedTy<'tcx>) -> print::Pat<'tcx> {
use print::{Pat, PatKind};
/// Prints an [`IntRange`] to a string for diagnostic purposes.
fn print_pat_range(&self, range: &IntRange, ty: RevealedTy<'tcx>) -> String {
use MaybeInfiniteInt::*;
let cx = self;
let kind = if matches!((range.lo, range.hi), (NegInfinity, PosInfinity)) {
PatKind::Print("_".to_string())
if matches!((range.lo, range.hi), (NegInfinity, PosInfinity)) {
"_".to_string()
} else if range.is_singleton() {
let lo = cx.hoist_pat_range_bdy(range.lo, ty);
let value = lo.as_finite().unwrap();
PatKind::Print(value.to_string())
value.to_string()
} else {
// We convert to an inclusive range for diagnostics.
let mut end = rustc_hir::RangeEnd::Included;
Expand All @@ -807,33 +806,24 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
range.hi
};
let hi = cx.hoist_pat_range_bdy(hi, ty);
PatKind::Print(PatRange { lo, hi, end, ty: ty.inner() }.to_string())
};

Pat { ty: ty.inner(), kind }
PatRange { lo, hi, end, ty: ty.inner() }.to_string()
}
}

/// Prints a [`WitnessPat`] to an owned string, for diagnostic purposes.
///
/// This panics for patterns that don't appear in diagnostics, like float ranges.
pub fn print_witness_pat(&self, pat: &WitnessPat<'p, 'tcx>) -> String {
// This works by converting the witness pattern to a `print::Pat`
// and then printing that, but callers don't need to know that.
self.hoist_witness_pat(pat).to_string()
}

/// Convert to a [`print::Pat`] for diagnostic purposes. This panics for patterns that don't
/// appear in diagnostics, like float ranges.
fn hoist_witness_pat(&self, pat: &WitnessPat<'p, 'tcx>) -> print::Pat<'tcx> {
use print::{FieldPat, Pat, PatKind};
let cx = self;
let hoist = |p| Box::new(cx.hoist_witness_pat(p));
let kind = match pat.ctor() {
Bool(b) => PatKind::Print(b.to_string()),
Str(s) => PatKind::Print(s.to_string()),
IntRange(range) => return self.hoist_pat_range(range, *pat.ty()),
let print = |p| cx.print_witness_pat(p);
match pat.ctor() {
Bool(b) => b.to_string(),
Str(s) => s.to_string(),
IntRange(range) => return self.print_pat_range(range, *pat.ty()),
Struct if pat.ty().is_box() => {
// Outside of the `alloc` crate, the only way to create a struct pattern
// of type `Box` is to use a `box` pattern via #[feature(box_patterns)].
PatKind::Print(format!("box {}", hoist(&pat.fields[0])))
format!("box {}", print(&pat.fields[0]))
}
Struct | Variant(_) | UnionField => {
let enum_info = match *pat.ty().kind() {
Expand All @@ -848,9 +838,9 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
let subpatterns = pat
.iter_fields()
.enumerate()
.map(|(i, pat)| FieldPat {
.map(|(i, pat)| print::FieldPat {
field: FieldIdx::new(i),
pattern: hoist(pat),
pattern: print(pat),
is_wildcard: would_print_as_wildcard(cx.tcx, pat),
})
.collect::<Vec<_>>();
Expand All @@ -864,12 +854,12 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
&subpatterns,
)
.unwrap();
PatKind::Print(s)
s
}
Ref => {
let mut s = String::new();
print::write_ref_like(&mut s, pat.ty().inner(), &hoist(&pat.fields[0])).unwrap();
PatKind::Print(s)
print::write_ref_like(&mut s, pat.ty().inner(), &print(&pat.fields[0])).unwrap();
s
}
Slice(slice) => {
let (prefix_len, has_dot_dot) = match slice.kind {
Expand Down Expand Up @@ -897,27 +887,23 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
}
}

let prefix = prefix.iter().map(hoist).collect::<Vec<_>>();
let suffix = suffix.iter().map(hoist).collect::<Vec<_>>();
let prefix = prefix.iter().map(print).collect::<Vec<_>>();
let suffix = suffix.iter().map(print).collect::<Vec<_>>();

let mut s = String::new();
print::write_slice_like(&mut s, &prefix, has_dot_dot, &suffix).unwrap();
PatKind::Print(s)
}
Never if self.tcx.features().never_patterns => PatKind::Print("!".to_string()),
Never | Wildcard | NonExhaustive | Hidden | PrivateUninhabited => {
PatKind::Print("_".to_string())
s
}
Never if self.tcx.features().never_patterns => "!".to_string(),
Never | Wildcard | NonExhaustive | Hidden | PrivateUninhabited => "_".to_string(),
Missing { .. } => bug!(
"trying to convert a `Missing` constructor into a `Pat`; this is probably a bug,
`Missing` should have been processed in `apply_constructors`"
),
F16Range(..) | F32Range(..) | F64Range(..) | F128Range(..) | Opaque(..) | Or => {
bug!("can't convert to pattern: {:?}", pat)
}
};

Pat { ty: pat.ty().inner(), kind }
}
}
}

Expand Down Expand Up @@ -993,7 +979,7 @@ impl<'p, 'tcx: 'p> PatCx for RustcPatCtxt<'p, 'tcx> {
overlaps_on: IntRange,
overlaps_with: &[&crate::pat::DeconstructedPat<Self>],
) {
let overlap_as_pat = self.hoist_pat_range(&overlaps_on, *pat.ty());
let overlap_as_pat = self.print_pat_range(&overlaps_on, *pat.ty());
let overlaps: Vec<_> = overlaps_with
.iter()
.map(|pat| pat.data().span)
Expand Down Expand Up @@ -1033,7 +1019,7 @@ impl<'p, 'tcx: 'p> PatCx for RustcPatCtxt<'p, 'tcx> {
suggested_range.end = rustc_hir::RangeEnd::Included;
suggested_range.to_string()
};
let gap_as_pat = self.hoist_pat_range(&gap, *pat.ty());
let gap_as_pat = self.print_pat_range(&gap, *pat.ty());
if gapped_with.is_empty() {
// If `gapped_with` is empty, `gap == T::MAX`.
self.tcx.emit_node_span_lint(
Expand Down
34 changes: 7 additions & 27 deletions compiler/rustc_pattern_analysis/src/rustc/print.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,32 +17,12 @@ use rustc_span::sym;
use rustc_target::abi::{FieldIdx, VariantIdx};

#[derive(Clone, Debug)]
pub(crate) struct FieldPat<'tcx> {
pub(crate) struct FieldPat {
pub(crate) field: FieldIdx,
pub(crate) pattern: Box<Pat<'tcx>>,
pub(crate) pattern: String,
pub(crate) is_wildcard: bool,
}

#[derive(Clone, Debug)]
pub(crate) struct Pat<'tcx> {
#[allow(dead_code)]
pub(crate) ty: Ty<'tcx>,
pub(crate) kind: PatKind,
}

#[derive(Clone, Debug)]
pub(crate) enum PatKind {
Print(String),
}

impl<'tcx> fmt::Display for Pat<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self.kind {
PatKind::Print(ref string) => write!(f, "{string}"),
}
}
}

/// Returns a closure that will return `""` when called the first time,
/// and then return `", "` when called any subsequent times.
/// Useful for printing comma-separated lists.
Expand All @@ -69,7 +49,7 @@ pub(crate) fn write_struct_like<'tcx>(
tcx: TyCtxt<'_>,
ty: Ty<'tcx>,
enum_info: &EnumInfo<'tcx>,
subpatterns: &[FieldPat<'tcx>],
subpatterns: &[FieldPat],
) -> fmt::Result {
let variant_and_name = match *enum_info {
EnumInfo::Enum { adt_def, variant_index } => {
Expand Down Expand Up @@ -148,7 +128,7 @@ pub(crate) fn write_struct_like<'tcx>(
pub(crate) fn write_ref_like<'tcx>(
f: &mut impl fmt::Write,
ty: Ty<'tcx>,
subpattern: &Pat<'tcx>,
subpattern: &str,
) -> fmt::Result {
match ty.kind() {
ty::Ref(_, _, mutbl) => {
Expand All @@ -159,11 +139,11 @@ pub(crate) fn write_ref_like<'tcx>(
write!(f, "{subpattern}")
}

pub(crate) fn write_slice_like<'tcx>(
pub(crate) fn write_slice_like(
f: &mut impl fmt::Write,
prefix: &[Box<Pat<'tcx>>],
prefix: &[String],
has_dot_dot: bool,
suffix: &[Box<Pat<'tcx>>],
suffix: &[String],
) -> fmt::Result {
let mut start_or_comma = start_or_comma();
write!(f, "[")?;
Expand Down

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