From ef24de24a82fe681581cc130f342363c47c0969a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 7 Jun 2024 07:48:48 +0200 Subject: Merging upstream version 1.75.0+dfsg1. Signed-off-by: Daniel Baumann --- compiler/rustc_mir_build/src/build/matches/mod.rs | 86 ++++++++++++--------- .../rustc_mir_build/src/build/matches/simplify.rs | 52 +++---------- compiler/rustc_mir_build/src/build/matches/test.rs | 87 ++++++++++------------ 3 files changed, 101 insertions(+), 124 deletions(-) (limited to 'compiler/rustc_mir_build/src/build/matches') diff --git a/compiler/rustc_mir_build/src/build/matches/mod.rs b/compiler/rustc_mir_build/src/build/matches/mod.rs index 6baf8c7d7..304870274 100644 --- a/compiler/rustc_mir_build/src/build/matches/mod.rs +++ b/compiler/rustc_mir_build/src/build/matches/mod.rs @@ -157,7 +157,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { /// [ 0. Pre-match ] /// | /// [ 1. Evaluate Scrutinee (expression being matched on) ] - /// [ (fake read of scrutinee) ] + /// [ (PlaceMention of scrutinee) ] /// | /// [ 2. Decision tree -- check discriminants ] <--------+ /// | | @@ -184,7 +184,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { /// /// We generate MIR in the following steps: /// - /// 1. Evaluate the scrutinee and add the fake read of it ([Builder::lower_scrutinee]). + /// 1. Evaluate the scrutinee and add the PlaceMention of it ([Builder::lower_scrutinee]). /// 2. Create the decision tree ([Builder::lower_match_tree]). /// 3. Determine the fake borrows that are needed from the places that were /// matched against and create the required temporaries for them @@ -223,6 +223,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let fake_borrow_temps = self.lower_match_tree( block, scrutinee_span, + &scrutinee_place, match_start_span, match_has_guard, &mut candidates, @@ -238,7 +239,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { ) } - /// Evaluate the scrutinee and add the fake read of it. + /// Evaluate the scrutinee and add the PlaceMention for it. fn lower_scrutinee( &mut self, mut block: BasicBlock, @@ -246,26 +247,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { scrutinee_span: Span, ) -> BlockAnd> { let scrutinee_place_builder = unpack!(block = self.as_place_builder(block, scrutinee)); - // Matching on a `scrutinee_place` with an uninhabited type doesn't - // generate any memory reads by itself, and so if the place "expression" - // contains unsafe operations like raw pointer dereferences or union - // field projections, we wouldn't know to require an `unsafe` block - // around a `match` equivalent to `std::intrinsics::unreachable()`. - // See issue #47412 for this hole being discovered in the wild. - // - // HACK(eddyb) Work around the above issue by adding a dummy inspection - // of `scrutinee_place`, specifically by applying `ReadForMatch`. - // - // NOTE: ReadForMatch also checks that the scrutinee is initialized. - // This is currently needed to not allow matching on an uninitialized, - // uninhabited value. If we get never patterns, those will check that - // the place is initialized, and so this read would only be used to - // check safety. - let cause_matched_place = FakeReadCause::ForMatchedPlace(None); - let source_info = self.source_info(scrutinee_span); - if let Some(scrutinee_place) = scrutinee_place_builder.try_to_place(self) { - self.cfg.push_fake_read(block, source_info, cause_matched_place, scrutinee_place); + let source_info = self.source_info(scrutinee_span); + self.cfg.push_place_mention(block, source_info, scrutinee_place); } block.and(scrutinee_place_builder) @@ -304,6 +288,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { &mut self, block: BasicBlock, scrutinee_span: Span, + scrutinee_place_builder: &PlaceBuilder<'tcx>, match_start_span: Span, match_has_guard: bool, candidates: &mut [&mut Candidate<'pat, 'tcx>], @@ -331,6 +316,33 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // otherwise block. Match checking will ensure this is actually // unreachable. let source_info = self.source_info(scrutinee_span); + + // Matching on a `scrutinee_place` with an uninhabited type doesn't + // generate any memory reads by itself, and so if the place "expression" + // contains unsafe operations like raw pointer dereferences or union + // field projections, we wouldn't know to require an `unsafe` block + // around a `match` equivalent to `std::intrinsics::unreachable()`. + // See issue #47412 for this hole being discovered in the wild. + // + // HACK(eddyb) Work around the above issue by adding a dummy inspection + // of `scrutinee_place`, specifically by applying `ReadForMatch`. + // + // NOTE: ReadForMatch also checks that the scrutinee is initialized. + // This is currently needed to not allow matching on an uninitialized, + // uninhabited value. If we get never patterns, those will check that + // the place is initialized, and so this read would only be used to + // check safety. + let cause_matched_place = FakeReadCause::ForMatchedPlace(None); + + if let Some(scrutinee_place) = scrutinee_place_builder.try_to_place(self) { + self.cfg.push_fake_read( + otherwise_block, + source_info, + cause_matched_place, + scrutinee_place, + ); + } + self.cfg.terminate(otherwise_block, source_info, TerminatorKind::Unreachable); } @@ -599,13 +611,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } _ => { - let place_builder = unpack!(block = self.as_place_builder(block, initializer)); - - if let Some(place) = place_builder.try_to_place(self) { - let source_info = self.source_info(initializer.span); - self.cfg.push_place_mention(block, source_info, place); - } - + let place_builder = + unpack!(block = self.lower_scrutinee(block, initializer, initializer.span)); self.place_into_pattern(block, &irrefutable_pat, place_builder, true) } } @@ -622,6 +629,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let fake_borrow_temps = self.lower_match_tree( block, irrefutable_pat.span, + &initializer, irrefutable_pat.span, false, &mut [&mut candidate], @@ -736,7 +744,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { self.cfg.push(block, Statement { source_info, kind: StatementKind::StorageLive(local_id) }); // Although there is almost always scope for given variable in corner cases // like #92893 we might get variable with no scope. - if let Some(region_scope) = self.region_scope_tree.var_scope(var.0.local_id) && schedule_drop { + if let Some(region_scope) = self.region_scope_tree.var_scope(var.0.local_id) + && schedule_drop + { self.schedule_drop(span, region_scope, local_id, DropKind::Storage); } Place::from(local_id) @@ -814,7 +824,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } } - PatKind::Constant { .. } | PatKind::Range { .. } | PatKind::Wild => {} + PatKind::Constant { .. } + | PatKind::Range { .. } + | PatKind::Wild + | PatKind::Error(_) => {} PatKind::Deref { ref subpattern } => { self.visit_primary_bindings(subpattern, pattern_user_ty.deref(), f); @@ -842,6 +855,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { self.visit_primary_bindings(subpattern, subpattern_user_ty, f) } + PatKind::InlineConstant { ref subpattern, .. } => { + self.visit_primary_bindings(subpattern, pattern_user_ty, f) + } + PatKind::Leaf { ref subpatterns } => { for subpattern in subpatterns { let subpattern_user_ty = pattern_user_ty.clone().leaf(subpattern.field); @@ -1018,7 +1035,7 @@ enum TestKind<'tcx> { ty: Ty<'tcx>, }, - /// Test whether the value falls within an inclusive or exclusive range + /// Test whether the value falls within an inclusive or exclusive range. Range(Box>), /// Test that the length of the slice is equal to `len`. @@ -1798,7 +1815,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let fake_borrow_ty = Ty::new_imm_ref(tcx, tcx.lifetimes.re_erased, fake_borrow_deref_ty); let mut fake_borrow_temp = LocalDecl::new(fake_borrow_ty, temp_span); - fake_borrow_temp.internal = self.local_decls[matched_place.local].internal; fake_borrow_temp.local_info = ClearCrossCrate::Set(Box::new(LocalInfo::FakeBorrow)); let fake_borrow_temp = self.local_decls.push(fake_borrow_temp); @@ -1833,6 +1849,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let fake_borrow_temps = self.lower_match_tree( block, pat.span, + &expr_place_builder, pat.span, false, &mut [&mut guard_candidate, &mut otherwise_candidate], @@ -2268,7 +2285,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { ty: var_ty, user_ty: if user_ty.is_empty() { None } else { Some(Box::new(user_ty)) }, source_info, - internal: false, local_info: ClearCrossCrate::Set(Box::new(LocalInfo::User(BindingForm::Var( VarBindingForm { binding_mode, @@ -2298,7 +2314,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { ty: Ty::new_imm_ref(tcx, tcx.lifetimes.re_erased, var_ty), user_ty: None, source_info, - internal: false, local_info: ClearCrossCrate::Set(Box::new(LocalInfo::User( BindingForm::RefForGuard, ))), @@ -2336,6 +2351,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let fake_borrow_temps = this.lower_match_tree( block, initializer_span, + &scrutinee, pattern.span, false, &mut [&mut candidate, &mut wildcard], diff --git a/compiler/rustc_mir_build/src/build/matches/simplify.rs b/compiler/rustc_mir_build/src/build/matches/simplify.rs index 17ac1f4e0..6a40c8d84 100644 --- a/compiler/rustc_mir_build/src/build/matches/simplify.rs +++ b/compiler/rustc_mir_build/src/build/matches/simplify.rs @@ -15,11 +15,7 @@ use crate::build::expr::as_place::PlaceBuilder; use crate::build::matches::{Ascription, Binding, Candidate, MatchPair}; use crate::build::Builder; -use rustc_hir::RangeEnd; use rustc_middle::thir::{self, *}; -use rustc_middle::ty; -use rustc_middle::ty::layout::IntegerExt; -use rustc_target::abi::{Integer, Size}; use std::mem; @@ -148,7 +144,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { match_pair: MatchPair<'pat, 'tcx>, candidate: &mut Candidate<'pat, 'tcx>, ) -> Result<(), MatchPair<'pat, 'tcx>> { - let tcx = self.tcx; match match_pair.pattern.kind { PatKind::AscribeUserType { ref subpattern, @@ -168,7 +163,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { Ok(()) } - PatKind::Wild => { + PatKind::Wild | PatKind::Error(_) => { // nothing left to do Ok(()) } @@ -204,41 +199,16 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { Err(match_pair) } - PatKind::Range(box PatRange { lo, hi, end }) => { - let (range, bias) = match *lo.ty().kind() { - ty::Char => { - (Some(('\u{0000}' as u128, '\u{10FFFF}' as u128, Size::from_bits(32))), 0) - } - ty::Int(ity) => { - let size = Integer::from_int_ty(&tcx, ity).size(); - let max = size.truncate(u128::MAX); - let bias = 1u128 << (size.bits() - 1); - (Some((0, max, size)), bias) - } - ty::Uint(uty) => { - let size = Integer::from_uint_ty(&tcx, uty).size(); - let max = size.truncate(u128::MAX); - (Some((0, max, size)), 0) - } - _ => (None, 0), - }; - if let Some((min, max, sz)) = range { - // We want to compare ranges numerically, but the order of the bitwise - // representation of signed integers does not match their numeric order. Thus, - // to correct the ordering, we need to shift the range of signed integers to - // correct the comparison. This is achieved by XORing with a bias (see - // pattern/_match.rs for another pertinent example of this pattern). - // - // Also, for performance, it's important to only do the second `try_to_bits` if - // necessary. - let lo = lo.try_to_bits(sz).unwrap() ^ bias; - if lo <= min { - let hi = hi.try_to_bits(sz).unwrap() ^ bias; - if hi > max || hi == max && end == RangeEnd::Included { - // Irrefutable pattern match. - return Ok(()); - } - } + PatKind::InlineConstant { subpattern: ref pattern, def: _ } => { + candidate.match_pairs.push(MatchPair::new(match_pair.place, pattern, self)); + + Ok(()) + } + + PatKind::Range(ref range) => { + if let Some(true) = range.is_full_range(self.tcx) { + // Irrefutable pattern match. + return Ok(()); } Err(match_pair) } diff --git a/compiler/rustc_mir_build/src/build/matches/test.rs b/compiler/rustc_mir_build/src/build/matches/test.rs index 795d1db8e..bdd4f2011 100644 --- a/compiler/rustc_mir_build/src/build/matches/test.rs +++ b/compiler/rustc_mir_build/src/build/matches/test.rs @@ -8,7 +8,6 @@ use crate::build::expr::as_place::PlaceBuilder; use crate::build::matches::{Candidate, MatchPair, Test, TestKind}; use crate::build::Builder; -use crate::thir::pattern::compare_const_vals; use rustc_data_structures::fx::FxIndexMap; use rustc_hir::{LangItem, RangeEnd}; use rustc_index::bit_set::BitSet; @@ -59,8 +58,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { }, PatKind::Range(ref range) => { - assert_eq!(range.lo.ty(), match_pair.pattern.ty); - assert_eq!(range.hi.ty(), match_pair.pattern.ty); + assert_eq!(range.ty, match_pair.pattern.ty); Test { span: match_pair.pattern.span, kind: TestKind::Range(range.clone()) } } @@ -73,11 +71,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { PatKind::Or { .. } => bug!("or-patterns should have already been handled"), PatKind::AscribeUserType { .. } + | PatKind::InlineConstant { .. } | PatKind::Array { .. } | PatKind::Wild | PatKind::Binding { .. } | PatKind::Leaf { .. } - | PatKind::Deref { .. } => self.error_simplifiable(match_pair), + | PatKind::Deref { .. } + | PatKind::Error(_) => self.error_simplifiable(match_pair), } } @@ -110,8 +110,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { | PatKind::Or { .. } | PatKind::Binding { .. } | PatKind::AscribeUserType { .. } + | PatKind::InlineConstant { .. } | PatKind::Leaf { .. } - | PatKind::Deref { .. } => { + | PatKind::Deref { .. } + | PatKind::Error(_) => { // don't know how to add these patterns to a switch false } @@ -236,18 +238,27 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { TestKind::Eq { value, ty } => { let tcx = self.tcx; - if let ty::Adt(def, _) = ty.kind() && Some(def.did()) == tcx.lang_items().string() { + if let ty::Adt(def, _) = ty.kind() + && Some(def.did()) == tcx.lang_items().string() + { if !tcx.features().string_deref_patterns { - bug!("matching on `String` went through without enabling string_deref_patterns"); + bug!( + "matching on `String` went through without enabling string_deref_patterns" + ); } let re_erased = tcx.lifetimes.re_erased; - let ref_string = self.temp(Ty::new_imm_ref(tcx,re_erased, ty), test.span); - let ref_str_ty = Ty::new_imm_ref(tcx,re_erased, tcx.types.str_); + let ref_string = self.temp(Ty::new_imm_ref(tcx, re_erased, ty), test.span); + let ref_str_ty = Ty::new_imm_ref(tcx, re_erased, tcx.types.str_); let ref_str = self.temp(ref_str_ty, test.span); let deref = tcx.require_lang_item(LangItem::Deref, None); let method = trait_method(tcx, deref, sym::deref, [ty]); let eq_block = self.cfg.start_new_block(); - self.cfg.push_assign(block, source_info, ref_string, Rvalue::Ref(re_erased, BorrowKind::Shared, place)); + self.cfg.push_assign( + block, + source_info, + ref_string, + Rvalue::Ref(re_erased, BorrowKind::Shared, place), + ); self.cfg.terminate( block, source_info, @@ -262,10 +273,17 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { target: Some(eq_block), unwind: UnwindAction::Continue, call_source: CallSource::Misc, - fn_span: source_info.span - } + fn_span: source_info.span, + }, + ); + self.non_scalar_compare( + eq_block, + make_target_blocks, + source_info, + value, + ref_str, + ref_str_ty, ); - self.non_scalar_compare(eq_block, make_target_blocks, source_info, value, ref_str, ref_str_ty); return; } if !ty.is_scalar() { @@ -289,11 +307,14 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } } - TestKind::Range(box PatRange { lo, hi, ref end }) => { + TestKind::Range(ref range) => { let lower_bound_success = self.cfg.start_new_block(); let target_blocks = make_target_blocks(self); // Test `val` by computing `lo <= val && val <= hi`, using primitive comparisons. + // FIXME: skip useless comparison when the range is half-open. + let lo = range.lo.to_const(range.ty, self.tcx); + let hi = range.hi.to_const(range.ty, self.tcx); let lo = self.literal_operand(test.span, lo); let hi = self.literal_operand(test.span, hi); let val = Operand::Copy(place); @@ -310,7 +331,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { lo, val.clone(), ); - let op = match *end { + let op = match range.end { RangeEnd::Included => BinOp::Le, RangeEnd::Excluded => BinOp::Lt, }; @@ -678,34 +699,18 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } (TestKind::Range(test), PatKind::Range(pat)) => { - use std::cmp::Ordering::*; - if test == pat { self.candidate_without_match_pair(match_pair_index, candidate); return Some(0); } - // For performance, it's important to only do the second - // `compare_const_vals` if necessary. - let no_overlap = if matches!( - (compare_const_vals(self.tcx, test.hi, pat.lo, self.param_env)?, test.end), - (Less, _) | (Equal, RangeEnd::Excluded) // test < pat - ) || matches!( - (compare_const_vals(self.tcx, test.lo, pat.hi, self.param_env)?, pat.end), - (Greater, _) | (Equal, RangeEnd::Excluded) // test > pat - ) { - Some(1) - } else { - None - }; - // If the testing range does not overlap with pattern range, // the pattern can be matched only if this test fails. - no_overlap + if !test.overlaps(pat, self.tcx, self.param_env)? { Some(1) } else { None } } (TestKind::Range(range), &PatKind::Constant { value }) => { - if let Some(false) = self.const_range_contains(&*range, value) { + if !range.contains(value, self.tcx, self.param_env)? { // `value` is not contained in the testing range, // so `value` can be matched only if this test fails. Some(1) @@ -797,27 +802,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { span_bug!(match_pair.pattern.span, "simplifiable pattern found: {:?}", match_pair.pattern) } - fn const_range_contains(&self, range: &PatRange<'tcx>, value: Const<'tcx>) -> Option { - use std::cmp::Ordering::*; - - // For performance, it's important to only do the second - // `compare_const_vals` if necessary. - Some( - matches!(compare_const_vals(self.tcx, range.lo, value, self.param_env)?, Less | Equal) - && matches!( - (compare_const_vals(self.tcx, value, range.hi, self.param_env)?, range.end), - (Less, _) | (Equal, RangeEnd::Included) - ), - ) - } - fn values_not_contained_in_range( &self, range: &PatRange<'tcx>, options: &FxIndexMap, u128>, ) -> Option { for &val in options.keys() { - if self.const_range_contains(range, val)? { + if range.contains(val, self.tcx, self.param_env)? { return Some(false); } } -- cgit v1.2.3