3 // After candidates have been simplified, the only match pairs that
4 // remain are those that require some sort of test. The functions here
5 // identify what tests are needed, perform the tests, and then filter
6 // the candidates based on the result.
8 use crate::build
::expr
::as_place
::PlaceBuilder
;
9 use crate::build
::matches
::{Candidate, MatchPair, Test, TestKind}
;
10 use crate::build
::Builder
;
11 use crate::thir
::pattern
::compare_const_vals
;
13 use rustc_data_structures
::fx
::FxIndexMap
;
14 use rustc_hir
::{LangItem, RangeEnd}
;
15 use rustc_index
::bit_set
::BitSet
;
16 use rustc_middle
::mir
::*;
17 use rustc_middle
::ty
::subst
::{GenericArg, Subst}
;
18 use rustc_middle
::ty
::util
::IntTypeExt
;
19 use rustc_middle
::ty
::{self, adjustment::PointerCast, Ty, TyCtxt}
;
20 use rustc_span
::def_id
::DefId
;
21 use rustc_span
::symbol
::{sym, Symbol}
;
22 use rustc_target
::abi
::VariantIdx
;
24 use std
::cmp
::Ordering
;
26 impl<'a
, 'tcx
> Builder
<'a
, 'tcx
> {
27 /// Identifies what test is needed to decide if `match_pair` is applicable.
29 /// It is a bug to call this with a not-fully-simplified pattern.
30 pub(super) fn test
<'pat
>(&mut self, match_pair
: &MatchPair
<'pat
, 'tcx
>) -> Test
<'tcx
> {
31 match *match_pair
.pattern
.kind
{
32 PatKind
::Variant { ref adt_def, substs: _, variant_index: _, subpatterns: _ }
=> Test
{
33 span
: match_pair
.pattern
.span
,
34 kind
: TestKind
::Switch
{
36 variants
: BitSet
::new_empty(adt_def
.variants
.len()),
40 PatKind
::Constant { .. }
if is_switch_ty(match_pair
.pattern
.ty
) => {
41 // For integers, we use a `SwitchInt` match, which allows
42 // us to handle more cases.
44 span
: match_pair
.pattern
.span
,
45 kind
: TestKind
::SwitchInt
{
46 switch_ty
: match_pair
.pattern
.ty
,
48 // these maps are empty to start; cases are
49 // added below in add_cases_to_switch
50 options
: Default
::default(),
55 PatKind
::Constant { value }
=> Test
{
56 span
: match_pair
.pattern
.span
,
57 kind
: TestKind
::Eq { value, ty: match_pair.pattern.ty }
,
60 PatKind
::Range(range
) => {
61 assert_eq
!(range
.lo
.ty
, match_pair
.pattern
.ty
);
62 assert_eq
!(range
.hi
.ty
, match_pair
.pattern
.ty
);
63 Test { span: match_pair.pattern.span, kind: TestKind::Range(range) }
66 PatKind
::Slice { ref prefix, ref slice, ref suffix }
=> {
67 let len
= prefix
.len() + suffix
.len();
68 let op
= if slice
.is_some() { BinOp::Ge }
else { BinOp::Eq }
;
69 Test { span: match_pair.pattern.span, kind: TestKind::Len { len: len as u64, op }
}
72 PatKind
::Or { .. }
=> bug
!("or-patterns should have already been handled"),
74 PatKind
::AscribeUserType { .. }
75 | PatKind
::Array { .. }
77 | PatKind
::Binding { .. }
78 | PatKind
::Leaf { .. }
79 | PatKind
::Deref { .. }
=> self.error_simplifyable(match_pair
),
83 pub(super) fn add_cases_to_switch
<'pat
>(
85 test_place
: &PlaceBuilder
<'tcx
>,
86 candidate
: &Candidate
<'pat
, 'tcx
>,
88 options
: &mut FxIndexMap
<&'tcx ty
::Const
<'tcx
>, u128
>,
90 let match_pair
= match candidate
.match_pairs
.iter().find(|mp
| mp
.place
== *test_place
) {
91 Some(match_pair
) => match_pair
,
97 match *match_pair
.pattern
.kind
{
98 PatKind
::Constant { value }
=> {
101 .or_insert_with(|| value
.eval_bits(self.tcx
, self.param_env
, switch_ty
));
104 PatKind
::Variant { .. }
=> {
105 panic
!("you should have called add_variants_to_switch instead!");
107 PatKind
::Range(range
) => {
108 // Check that none of the switch values are in the range.
109 self.values_not_contained_in_range(range
, options
).unwrap_or(false)
111 PatKind
::Slice { .. }
112 | PatKind
::Array { .. }
115 | PatKind
::Binding { .. }
116 | PatKind
::AscribeUserType { .. }
117 | PatKind
::Leaf { .. }
118 | PatKind
::Deref { .. }
=> {
119 // don't know how to add these patterns to a switch
125 pub(super) fn add_variants_to_switch
<'pat
>(
127 test_place
: &PlaceBuilder
<'tcx
>,
128 candidate
: &Candidate
<'pat
, 'tcx
>,
129 variants
: &mut BitSet
<VariantIdx
>,
131 let match_pair
= match candidate
.match_pairs
.iter().find(|mp
| mp
.place
== *test_place
) {
132 Some(match_pair
) => match_pair
,
138 match *match_pair
.pattern
.kind
{
139 PatKind
::Variant { adt_def: _, variant_index, .. }
=> {
140 // We have a pattern testing for variant `variant_index`
141 // set the corresponding index to true
142 variants
.insert(variant_index
);
146 // don't know how to add these patterns to a switch
152 pub(super) fn perform_test(
155 place_builder
: PlaceBuilder
<'tcx
>,
157 make_target_blocks
: impl FnOnce(&mut Self) -> Vec
<BasicBlock
>,
159 let place
: Place
<'tcx
>;
160 if let Ok(test_place_builder
) =
161 place_builder
.try_upvars_resolved(self.tcx
, self.typeck_results
)
163 place
= test_place_builder
.into_place(self.tcx
, self.typeck_results
);
168 "perform_test({:?}, {:?}: {:?}, {:?})",
171 place
.ty(&self.local_decls
, self.tcx
),
175 let source_info
= self.source_info(test
.span
);
177 TestKind
::Switch { adt_def, ref variants }
=> {
178 let target_blocks
= make_target_blocks(self);
179 // Variants is a BitVec of indexes into adt_def.variants.
180 let num_enum_variants
= adt_def
.variants
.len();
181 debug_assert_eq
!(target_blocks
.len(), num_enum_variants
+ 1);
182 let otherwise_block
= *target_blocks
.last().unwrap();
184 let switch_targets
= SwitchTargets
::new(
185 adt_def
.discriminants(tcx
).filter_map(|(idx
, discr
)| {
186 if variants
.contains(idx
) {
188 target_blocks
[idx
.index()],
190 "no canididates for tested discriminant: {:?}",
193 Some((discr
.val
, target_blocks
[idx
.index()]))
196 target_blocks
[idx
.index()],
198 "found canididates for untested discriminant: {:?}",
206 debug
!("num_enum_variants: {}, variants: {:?}", num_enum_variants
, variants
);
207 let discr_ty
= adt_def
.repr
.discr_type().to_ty(tcx
);
208 let discr
= self.temp(discr_ty
, test
.span
);
209 self.cfg
.push_assign(block
, source_info
, discr
, Rvalue
::Discriminant(place
));
213 TerminatorKind
::SwitchInt
{
214 discr
: Operand
::Move(discr
),
216 targets
: switch_targets
,
221 TestKind
::SwitchInt { switch_ty, ref options }
=> {
222 let target_blocks
= make_target_blocks(self);
223 let terminator
= if *switch_ty
.kind() == ty
::Bool
{
224 assert
!(!options
.is_empty() && options
.len() <= 2);
225 if let [first_bb
, second_bb
] = *target_blocks
{
226 let (true_bb
, false_bb
) = match options
[0] {
227 1 => (first_bb
, second_bb
),
228 0 => (second_bb
, first_bb
),
229 v
=> span_bug
!(test
.span
, "expected boolean value but got {:?}", v
),
231 TerminatorKind
::if_(self.tcx
, Operand
::Copy(place
), true_bb
, false_bb
)
233 bug
!("`TestKind::SwitchInt` on `bool` should have two targets")
236 // The switch may be inexhaustive so we have a catch all block
237 debug_assert_eq
!(options
.len() + 1, target_blocks
.len());
238 let otherwise_block
= *target_blocks
.last().unwrap();
239 let switch_targets
= SwitchTargets
::new(
240 options
.values().copied().zip(target_blocks
),
243 TerminatorKind
::SwitchInt
{
244 discr
: Operand
::Copy(place
),
246 targets
: switch_targets
,
249 self.cfg
.terminate(block
, source_info
, terminator
);
252 TestKind
::Eq { value, ty }
=> {
254 // Use `PartialEq::eq` instead of `BinOp::Eq`
255 // (the binop can only handle primitives)
256 self.non_scalar_compare(
264 } else if let [success
, fail
] = *make_target_blocks(self) {
265 assert_eq
!(value
.ty
, ty
);
266 let expect
= self.literal_operand(test
.span
, value
);
267 let val
= Operand
::Copy(place
);
268 self.compare(block
, success
, fail
, source_info
, BinOp
::Eq
, expect
, val
);
270 bug
!("`TestKind::Eq` should have two target blocks");
274 TestKind
::Range(PatRange { ref lo, ref hi, ref end }
) => {
275 let lower_bound_success
= self.cfg
.start_new_block();
276 let target_blocks
= make_target_blocks(self);
278 // Test `val` by computing `lo <= val && val <= hi`, using primitive comparisons.
279 let lo
= self.literal_operand(test
.span
, lo
);
280 let hi
= self.literal_operand(test
.span
, hi
);
281 let val
= Operand
::Copy(place
);
283 if let [success
, fail
] = *target_blocks
{
293 let op
= match *end
{
294 RangeEnd
::Included
=> BinOp
::Le
,
295 RangeEnd
::Excluded
=> BinOp
::Lt
,
297 self.compare(lower_bound_success
, success
, fail
, source_info
, op
, val
, hi
);
299 bug
!("`TestKind::Range` should have two target blocks");
303 TestKind
::Len { len, op }
=> {
304 let target_blocks
= make_target_blocks(self);
306 let usize_ty
= self.tcx
.types
.usize;
307 let actual
= self.temp(usize_ty
, test
.span
);
309 // actual = len(place)
310 self.cfg
.push_assign(block
, source_info
, actual
, Rvalue
::Len(place
));
313 let expected
= self.push_usize(block
, source_info
, len
);
315 if let [true_bb
, false_bb
] = *target_blocks
{
316 // result = actual == expected OR result = actual < expected
317 // branch based on result
324 Operand
::Move(actual
),
325 Operand
::Move(expected
),
328 bug
!("`TestKind::Len` should have two target blocks");
334 /// Compare using the provided built-in comparison operator
338 success_block
: BasicBlock
,
339 fail_block
: BasicBlock
,
340 source_info
: SourceInfo
,
343 right
: Operand
<'tcx
>,
345 let bool_ty
= self.tcx
.types
.bool
;
346 let result
= self.temp(bool_ty
, source_info
.span
);
348 // result = op(left, right)
349 self.cfg
.push_assign(block
, source_info
, result
, Rvalue
::BinaryOp(op
, box (left
, right
)));
351 // branch based on result
355 TerminatorKind
::if_(self.tcx
, Operand
::Move(result
), success_block
, fail_block
),
359 /// Compare two `&T` values using `<T as std::compare::PartialEq>::eq`
360 fn non_scalar_compare(
363 make_target_blocks
: impl FnOnce(&mut Self) -> Vec
<BasicBlock
>,
364 source_info
: SourceInfo
,
365 value
: &'tcx ty
::Const
<'tcx
>,
369 let mut expect
= self.literal_operand(source_info
.span
, value
);
370 let mut val
= Operand
::Copy(place
);
372 // If we're using `b"..."` as a pattern, we need to insert an
373 // unsizing coercion, as the byte string has the type `&[u8; N]`.
375 // We want to do this even when the scrutinee is a reference to an
376 // array, so we can call `<[u8]>::eq` rather than having to find an
378 let unsize
= |ty
: Ty
<'tcx
>| match ty
.kind() {
379 ty
::Ref(region
, rty
, _
) => match rty
.kind() {
380 ty
::Array(inner_ty
, n
) => Some((region
, inner_ty
, n
)),
385 let opt_ref_ty
= unsize(ty
);
386 let opt_ref_test_ty
= unsize(value
.ty
);
387 match (opt_ref_ty
, opt_ref_test_ty
) {
388 // nothing to do, neither is an array
390 (Some((region
, elem_ty
, _
)), _
) | (None
, Some((region
, elem_ty
, _
))) => {
393 ty
= tcx
.mk_imm_ref(region
, tcx
.mk_slice(elem_ty
));
394 if opt_ref_ty
.is_some() {
395 let temp
= self.temp(ty
, source_info
.span
);
396 self.cfg
.push_assign(
400 Rvalue
::Cast(CastKind
::Pointer(PointerCast
::Unsize
), val
, ty
),
402 val
= Operand
::Move(temp
);
404 if opt_ref_test_ty
.is_some() {
405 let slice
= self.temp(ty
, source_info
.span
);
406 self.cfg
.push_assign(
410 Rvalue
::Cast(CastKind
::Pointer(PointerCast
::Unsize
), expect
, ty
),
412 expect
= Operand
::Move(slice
);
417 let deref_ty
= match *ty
.kind() {
418 ty
::Ref(_
, deref_ty
, _
) => deref_ty
,
419 _
=> bug
!("non_scalar_compare called on non-reference type: {}", ty
),
422 let eq_def_id
= self.tcx
.require_lang_item(LangItem
::PartialEq
, None
);
423 let method
= trait_method(self.tcx
, eq_def_id
, sym
::eq
, deref_ty
, &[deref_ty
.into()]);
425 let bool_ty
= self.tcx
.types
.bool
;
426 let eq_result
= self.temp(bool_ty
, source_info
.span
);
427 let eq_block
= self.cfg
.start_new_block();
431 TerminatorKind
::Call
{
432 func
: Operand
::Constant(box Constant
{
433 span
: source_info
.span
,
435 // FIXME(#54571): This constant comes from user input (a
436 // constant in a pattern). Are there forms where users can add
437 // type annotations here? For example, an associated constant?
438 // Need to experiment.
441 literal
: method
.into(),
443 args
: vec
![val
, expect
],
444 destination
: Some((eq_result
, eq_block
)),
446 from_hir_call
: false,
447 fn_span
: source_info
.span
,
450 self.diverge_from(block
);
452 if let [success_block
, fail_block
] = *make_target_blocks(self) {
457 TerminatorKind
::if_(self.tcx
, Operand
::Move(eq_result
), success_block
, fail_block
),
460 bug
!("`TestKind::Eq` should have two target blocks")
464 /// Given that we are performing `test` against `test_place`, this job
465 /// sorts out what the status of `candidate` will be after the test. See
466 /// `test_candidates` for the usage of this function. The returned index is
467 /// the index that this candidate should be placed in the
468 /// `target_candidates` vec. The candidate may be modified to update its
471 /// So, for example, if this candidate is `x @ Some(P0)` and the `Test` is
472 /// a variant test, then we would modify the candidate to be `(x as
473 /// Option).0 @ P0` and return the index corresponding to the variant
476 /// However, in some cases, the test may just not be relevant to candidate.
477 /// For example, suppose we are testing whether `foo.x == 22`, but in one
478 /// match arm we have `Foo { x: _, ... }`... in that case, the test for
479 /// what value `x` has has no particular relevance to this candidate. In
480 /// such cases, this function just returns None without doing anything.
481 /// This is used by the overall `match_candidates` algorithm to structure
482 /// the match as a whole. See `match_candidates` for more details.
484 /// FIXME(#29623). In some cases, we have some tricky choices to make. for
485 /// example, if we are testing that `x == 22`, but the candidate is `x @
486 /// 13..55`, what should we do? In the event that the test is true, we know
487 /// that the candidate applies, but in the event of false, we don't know
488 /// that it *doesn't* apply. For now, we return false, indicate that the
489 /// test does not apply to this candidate, but it might be we can get
490 /// tighter match code if we do something a bit different.
491 pub(super) fn sort_candidate
<'pat
>(
493 test_place
: &PlaceBuilder
<'tcx
>,
495 candidate
: &mut Candidate
<'pat
, 'tcx
>,
497 // Find the match_pair for this place (if any). At present,
498 // afaik, there can be at most one. (In the future, if we
499 // adopted a more general `@` operator, there might be more
500 // than one, but it'd be very unusual to have two sides that
501 // both require tests; you'd expect one side to be simplified
503 let (match_pair_index
, match_pair
) =
504 candidate
.match_pairs
.iter().enumerate().find(|&(_
, mp
)| mp
.place
== *test_place
)?
;
506 match (&test
.kind
, &*match_pair
.pattern
.kind
) {
507 // If we are performing a variant switch, then this
508 // informs variant patterns, but nothing else.
510 &TestKind
::Switch { adt_def: tested_adt_def, .. }
,
511 &PatKind
::Variant { adt_def, variant_index, ref subpatterns, .. }
,
513 assert_eq
!(adt_def
, tested_adt_def
);
514 self.candidate_after_variant_switch(
521 Some(variant_index
.as_usize())
524 (&TestKind
::Switch { .. }
, _
) => None
,
526 // If we are performing a switch over integers, then this informs integer
527 // equality, but nothing else.
529 // FIXME(#29623) we could use PatKind::Range to rule
530 // things out here, in some cases.
532 &TestKind
::SwitchInt { switch_ty: _, ref options }
,
533 &PatKind
::Constant { ref value }
,
534 ) if is_switch_ty(match_pair
.pattern
.ty
) => {
535 let index
= options
.get_index_of(value
).unwrap();
536 self.candidate_without_match_pair(match_pair_index
, candidate
);
540 (&TestKind
::SwitchInt { switch_ty: _, ref options }
, &PatKind
::Range(range
)) => {
542 self.values_not_contained_in_range(range
, options
).unwrap_or(false);
545 // No switch values are contained in the pattern range,
546 // so the pattern can be matched only if this test fails.
547 let otherwise
= options
.len();
554 (&TestKind
::SwitchInt { .. }
, _
) => None
,
557 &TestKind
::Len { len: test_len, op: BinOp::Eq }
,
558 &PatKind
::Slice { ref prefix, ref slice, ref suffix }
,
560 let pat_len
= (prefix
.len() + suffix
.len()) as u64;
561 match (test_len
.cmp(&pat_len
), slice
) {
562 (Ordering
::Equal
, &None
) => {
563 // on true, min_len = len = $actual_length,
564 // on false, len != $actual_length
565 self.candidate_after_slice_test(
574 (Ordering
::Less
, _
) => {
575 // test_len < pat_len. If $actual_len = test_len,
576 // then $actual_len < pat_len and we don't have
580 (Ordering
::Equal
| Ordering
::Greater
, &Some(_
)) => {
581 // This can match both if $actual_len = test_len >= pat_len,
582 // and if $actual_len > test_len. We can't advance.
585 (Ordering
::Greater
, &None
) => {
586 // test_len != pat_len, so if $actual_len = test_len, then
587 // $actual_len != pat_len.
594 &TestKind
::Len { len: test_len, op: BinOp::Ge }
,
595 &PatKind
::Slice { ref prefix, ref slice, ref suffix }
,
597 // the test is `$actual_len >= test_len`
598 let pat_len
= (prefix
.len() + suffix
.len()) as u64;
599 match (test_len
.cmp(&pat_len
), slice
) {
600 (Ordering
::Equal
, &Some(_
)) => {
601 // $actual_len >= test_len = pat_len,
603 self.candidate_after_slice_test(
612 (Ordering
::Less
, _
) | (Ordering
::Equal
, &None
) => {
613 // test_len <= pat_len. If $actual_len < test_len,
614 // then it is also < pat_len, so the test passing is
615 // necessary (but insufficient).
618 (Ordering
::Greater
, &None
) => {
619 // test_len > pat_len. If $actual_len >= test_len > pat_len,
620 // then we know we won't have a match.
623 (Ordering
::Greater
, &Some(_
)) => {
624 // test_len < pat_len, and is therefore less
625 // strict. This can still go both ways.
631 (&TestKind
::Range(test
), &PatKind
::Range(pat
)) => {
633 self.candidate_without_match_pair(match_pair_index
, candidate
);
637 let no_overlap
= (|| {
638 use rustc_hir
::RangeEnd
::*;
639 use std
::cmp
::Ordering
::*;
643 let test_ty
= test
.lo
.ty
;
644 let lo
= compare_const_vals(tcx
, test
.lo
, pat
.hi
, self.param_env
, test_ty
)?
;
645 let hi
= compare_const_vals(tcx
, test
.hi
, pat
.lo
, self.param_env
, test_ty
)?
;
647 match (test
.end
, pat
.end
, lo
, hi
) {
650 (_
, Excluded
, Equal
, _
) |
653 (Excluded
, _
, _
, Equal
) => Some(true),
658 if let Some(true) = no_overlap
{
659 // Testing range does not overlap with pattern range,
660 // so the pattern can be matched only if this test fails.
667 (&TestKind
::Range(range
), &PatKind
::Constant { value }
) => {
668 if let Some(false) = self.const_range_contains(range
, value
) {
669 // `value` is not contained in the testing range,
670 // so `value` can be matched only if this test fails.
677 (&TestKind
::Range { .. }
, _
) => None
,
679 (&TestKind
::Eq { .. }
| &TestKind
::Len { .. }
, _
) => {
680 // The call to `self.test(&match_pair)` below is not actually used to generate any
681 // MIR. Instead, we just want to compare with `test` (the parameter of the method)
682 // to see if it is the same.
684 // However, at this point we can still encounter or-patterns that were extracted
685 // from previous calls to `sort_candidate`, so we need to manually address that
686 // case to avoid panicking in `self.test()`.
687 if let PatKind
::Or { .. }
= &*match_pair
.pattern
.kind
{
691 // These are all binary tests.
693 // FIXME(#29623) we can be more clever here
694 let pattern_test
= self.test(&match_pair
);
695 if pattern_test
.kind
== test
.kind
{
696 self.candidate_without_match_pair(match_pair_index
, candidate
);
705 fn candidate_without_match_pair(
707 match_pair_index
: usize,
708 candidate
: &mut Candidate
<'_
, 'tcx
>,
710 candidate
.match_pairs
.remove(match_pair_index
);
713 fn candidate_after_slice_test
<'pat
>(
715 match_pair_index
: usize,
716 candidate
: &mut Candidate
<'pat
, 'tcx
>,
717 prefix
: &'pat
[Pat
<'tcx
>],
718 opt_slice
: Option
<&'pat Pat
<'tcx
>>,
719 suffix
: &'pat
[Pat
<'tcx
>],
721 let removed_place
= candidate
.match_pairs
.remove(match_pair_index
).place
;
722 self.prefix_slice_suffix(
723 &mut candidate
.match_pairs
,
731 fn candidate_after_variant_switch
<'pat
>(
733 match_pair_index
: usize,
734 adt_def
: &'tcx ty
::AdtDef
,
735 variant_index
: VariantIdx
,
736 subpatterns
: &'pat
[FieldPat
<'tcx
>],
737 candidate
: &mut Candidate
<'pat
, 'tcx
>,
739 let match_pair
= candidate
.match_pairs
.remove(match_pair_index
);
741 // So, if we have a match-pattern like `x @ Enum::Variant(P1, P2)`,
742 // we want to create a set of derived match-patterns like
743 // `(x as Variant).0 @ P1` and `(x as Variant).1 @ P1`.
744 let elem
= ProjectionElem
::Downcast(
745 Some(adt_def
.variants
[variant_index
].ident
.name
),
748 let downcast_place
= match_pair
.place
.project(elem
); // `(x as Variant)`
749 let consequent_match_pairs
= subpatterns
.iter().map(|subpattern
| {
750 // e.g., `(x as Variant).0`
751 let place
= downcast_place
.clone().field(subpattern
.field
, subpattern
.pattern
.ty
);
752 // e.g., `(x as Variant).0 @ P1`
753 MatchPair
::new(place
, &subpattern
.pattern
)
756 candidate
.match_pairs
.extend(consequent_match_pairs
);
759 fn error_simplifyable
<'pat
>(&mut self, match_pair
: &MatchPair
<'pat
, 'tcx
>) -> ! {
760 span_bug
!(match_pair
.pattern
.span
, "simplifyable pattern found: {:?}", match_pair
.pattern
)
763 fn const_range_contains(
765 range
: PatRange
<'tcx
>,
766 value
: &'tcx ty
::Const
<'tcx
>,
768 use std
::cmp
::Ordering
::*;
772 let a
= compare_const_vals(tcx
, range
.lo
, value
, self.param_env
, range
.lo
.ty
)?
;
773 let b
= compare_const_vals(tcx
, value
, range
.hi
, self.param_env
, range
.lo
.ty
)?
;
775 match (b
, range
.end
) {
776 (Less
, _
) | (Equal
, RangeEnd
::Included
) if a
!= Greater
=> Some(true),
781 fn values_not_contained_in_range(
783 range
: PatRange
<'tcx
>,
784 options
: &FxIndexMap
<&'tcx ty
::Const
<'tcx
>, u128
>,
786 for &val
in options
.keys() {
787 if self.const_range_contains(range
, val
)?
{
797 pub(super) fn targets(&self) -> usize {
799 TestKind
::Eq { .. }
| TestKind
::Range(_
) | TestKind
::Len { .. }
=> 2,
800 TestKind
::Switch { adt_def, .. }
=> {
801 // While the switch that we generate doesn't test for all
802 // variants, we have a target for each variant and the
803 // otherwise case, and we make sure that all of the cases not
804 // specified have the same block.
805 adt_def
.variants
.len() + 1
807 TestKind
::SwitchInt { switch_ty, ref options, .. }
=> {
808 if switch_ty
.is_bool() {
809 // `bool` is special cased in `perform_test` to always
810 // branch to two blocks.
820 fn is_switch_ty(ty
: Ty
<'_
>) -> bool
{
821 ty
.is_integral() || ty
.is_char() || ty
.is_bool()
824 fn trait_method
<'tcx
>(
829 params
: &[GenericArg
<'tcx
>],
830 ) -> &'tcx ty
::Const
<'tcx
> {
831 let substs
= tcx
.mk_substs_trait(self_ty
, params
);
833 // The unhygienic comparison here is acceptable because this is only
834 // used on known traits.
836 .associated_items(trait_def_id
)
837 .filter_by_name_unhygienic(method_name
)
838 .find(|item
| item
.kind
== ty
::AssocKind
::Fn
)
839 .expect("trait method not found");
841 let method_ty
= tcx
.type_of(item
.def_id
);
842 let method_ty
= method_ty
.subst(tcx
, substs
);
843 ty
::Const
::zero_sized(tcx
, method_ty
)