diff options
Diffstat (limited to 'compiler/rustc_mir_build/src/build/expr/as_rvalue.rs')
| -rw-r--r-- | compiler/rustc_mir_build/src/build/expr/as_rvalue.rs | 174 |
1 files changed, 126 insertions, 48 deletions
diff --git a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs index a4e48c154..8631749a5 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs @@ -1,14 +1,15 @@ //! See docs in `build/expr/mod.rs`. -use rustc_index::vec::Idx; +use rustc_index::vec::{Idx, IndexVec}; use rustc_middle::ty::util::IntTypeExt; -use rustc_target::abi::{Abi, Primitive}; +use rustc_target::abi::{Abi, FieldIdx, Primitive}; use crate::build::expr::as_place::PlaceBase; use crate::build::expr::category::{Category, RvalueFunc}; use crate::build::{BlockAnd, BlockAndExtension, Builder, NeedsTemporary}; use rustc_hir::lang_items::LangItem; use rustc_middle::middle::region; +use rustc_middle::mir::interpret::Scalar; use rustc_middle::mir::AssertKind; use rustc_middle::mir::Place; use rustc_middle::mir::*; @@ -63,7 +64,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { block, scope, &this.thir[value], - None, + LocalInfo::Boring, NeedsTemporary::No ) ); @@ -72,19 +73,34 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } ExprKind::Binary { op, lhs, rhs } => { let lhs = unpack!( - block = - this.as_operand(block, scope, &this.thir[lhs], None, NeedsTemporary::Maybe) + block = this.as_operand( + block, + scope, + &this.thir[lhs], + LocalInfo::Boring, + NeedsTemporary::Maybe + ) ); let rhs = unpack!( - block = - this.as_operand(block, scope, &this.thir[rhs], None, NeedsTemporary::No) + block = this.as_operand( + block, + scope, + &this.thir[rhs], + LocalInfo::Boring, + NeedsTemporary::No + ) ); this.build_binary_op(block, op, expr_span, expr.ty, lhs, rhs) } ExprKind::Unary { op, arg } => { let arg = unpack!( - block = - this.as_operand(block, scope, &this.thir[arg], None, NeedsTemporary::No) + block = this.as_operand( + block, + scope, + &this.thir[arg], + LocalInfo::Boring, + NeedsTemporary::No + ) ); // Check for -MIN on signed integers if this.check_overflow && op == UnOp::Neg && expr.ty.is_signed() { @@ -155,7 +171,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { args: vec![Operand::Move(size), Operand::Move(align)], destination: storage, target: Some(success), - cleanup: None, + unwind: UnwindAction::Continue, from_hir_call: false, fn_span: expr_span, }, @@ -259,7 +275,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } else { let ty = source.ty; let source = unpack!( - block = this.as_operand(block, scope, source, None, NeedsTemporary::No) + block = this.as_operand(block, scope, source, LocalInfo::Boring, NeedsTemporary::No) ); (source, ty) }; @@ -271,8 +287,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } ExprKind::Pointer { cast, source } => { let source = unpack!( - block = - this.as_operand(block, scope, &this.thir[source], None, NeedsTemporary::No) + block = this.as_operand( + block, + scope, + &this.thir[source], + LocalInfo::Boring, + NeedsTemporary::No + ) ); block.and(Rvalue::Cast(CastKind::Pointer(cast), source, expr.ty)) } @@ -305,7 +326,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // first process the set of fields let el_ty = expr.ty.sequence_element_type(this.tcx); - let fields: Vec<_> = fields + let fields: IndexVec<FieldIdx, _> = fields .into_iter() .copied() .map(|f| { @@ -314,7 +335,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { block, scope, &this.thir[f], - None, + LocalInfo::Boring, NeedsTemporary::Maybe ) ) @@ -326,7 +347,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { ExprKind::Tuple { ref fields } => { // see (*) above // first process the set of fields - let fields: Vec<_> = fields + let fields: IndexVec<FieldIdx, _> = fields .into_iter() .copied() .map(|f| { @@ -335,7 +356,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { block, scope, &this.thir[f], - None, + LocalInfo::Boring, NeedsTemporary::Maybe ) ) @@ -380,7 +401,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } // see (*) above - let operands: Vec<_> = upvars + let operands: IndexVec<FieldIdx, _> = upvars .into_iter() .copied() .map(|upvar| { @@ -423,7 +444,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { block, scope, upvar, - None, + LocalInfo::Boring, NeedsTemporary::Maybe ) ) @@ -501,8 +522,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { Category::of(&expr.kind), Some(Category::Rvalue(RvalueFunc::AsRvalue) | Category::Constant) )); - let operand = - unpack!(block = this.as_operand(block, scope, expr, None, NeedsTemporary::No)); + let operand = unpack!( + block = + this.as_operand(block, scope, expr, LocalInfo::Boring, NeedsTemporary::No) + ); block.and(Rvalue::Use(operand)) } } @@ -519,30 +542,78 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { ) -> BlockAnd<Rvalue<'tcx>> { let source_info = self.source_info(span); let bool_ty = self.tcx.types.bool; - if self.check_overflow && op.is_checkable() && ty.is_integral() { - let result_tup = self.tcx.mk_tup(&[ty, bool_ty]); - let result_value = self.temp(result_tup, span); - - self.cfg.push_assign( - block, - source_info, - result_value, - Rvalue::CheckedBinaryOp(op, Box::new((lhs.to_copy(), rhs.to_copy()))), - ); - let val_fld = Field::new(0); - let of_fld = Field::new(1); + let rvalue = match op { + BinOp::Add | BinOp::Sub | BinOp::Mul if self.check_overflow && ty.is_integral() => { + let result_tup = self.tcx.mk_tup(&[ty, bool_ty]); + let result_value = self.temp(result_tup, span); - let tcx = self.tcx; - let val = tcx.mk_place_field(result_value, val_fld, ty); - let of = tcx.mk_place_field(result_value, of_fld, bool_ty); + self.cfg.push_assign( + block, + source_info, + result_value, + Rvalue::CheckedBinaryOp(op, Box::new((lhs.to_copy(), rhs.to_copy()))), + ); + let val_fld = FieldIdx::new(0); + let of_fld = FieldIdx::new(1); - let err = AssertKind::Overflow(op, lhs, rhs); + let tcx = self.tcx; + let val = tcx.mk_place_field(result_value, val_fld, ty); + let of = tcx.mk_place_field(result_value, of_fld, bool_ty); - block = self.assert(block, Operand::Move(of), false, err, span); + let err = AssertKind::Overflow(op, lhs, rhs); + block = self.assert(block, Operand::Move(of), false, err, span); - block.and(Rvalue::Use(Operand::Move(val))) - } else { - if ty.is_integral() && (op == BinOp::Div || op == BinOp::Rem) { + Rvalue::Use(Operand::Move(val)) + } + BinOp::Shl | BinOp::Shr if self.check_overflow && ty.is_integral() => { + // For an unsigned RHS, the shift is in-range for `rhs < bits`. + // For a signed RHS, `IntToInt` cast to the equivalent unsigned + // type and do that same comparison. Because the type is the + // same size, there's no negative shift amount that ends up + // overlapping with valid ones, thus it catches negatives too. + let (lhs_size, _) = ty.int_size_and_signed(self.tcx); + let rhs_ty = rhs.ty(&self.local_decls, self.tcx); + let (rhs_size, _) = rhs_ty.int_size_and_signed(self.tcx); + + let (unsigned_rhs, unsigned_ty) = match rhs_ty.kind() { + ty::Uint(_) => (rhs.to_copy(), rhs_ty), + ty::Int(int_width) => { + let uint_ty = self.tcx.mk_mach_uint(int_width.to_unsigned()); + let rhs_temp = self.temp(uint_ty, span); + self.cfg.push_assign( + block, + source_info, + rhs_temp, + Rvalue::Cast(CastKind::IntToInt, rhs.to_copy(), uint_ty), + ); + (Operand::Move(rhs_temp), uint_ty) + } + _ => unreachable!("only integers are shiftable"), + }; + + // This can't overflow because the largest shiftable types are 128-bit, + // which fits in `u8`, the smallest possible `unsigned_ty`. + // (And `from_uint` will `bug!` if that's ever no longer true.) + let lhs_bits = Operand::const_from_scalar( + self.tcx, + unsigned_ty, + Scalar::from_uint(lhs_size.bits(), rhs_size), + span, + ); + + let inbounds = self.temp(bool_ty, span); + self.cfg.push_assign( + block, + source_info, + inbounds, + Rvalue::BinaryOp(BinOp::Lt, Box::new((unsigned_rhs, lhs_bits))), + ); + + let overflow_err = AssertKind::Overflow(op, lhs.to_copy(), rhs.to_copy()); + block = self.assert(block, Operand::Move(inbounds), true, overflow_err, span); + Rvalue::BinaryOp(op, Box::new((lhs, rhs))) + } + BinOp::Div | BinOp::Rem if ty.is_integral() => { // Checking division and remainder is more complex, since we 1. always check // and 2. there are two possible failure cases, divide-by-zero and overflow. @@ -601,10 +672,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { block = self.assert(block, Operand::Move(of), false, overflow_err, span); } - } - block.and(Rvalue::BinaryOp(op, Box::new((lhs, rhs)))) - } + Rvalue::BinaryOp(op, Box::new((lhs, rhs))) + } + _ => Rvalue::BinaryOp(op, Box::new((lhs, rhs))), + }; + block.and(rvalue) } fn build_zero_repeat( @@ -621,21 +694,26 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // Repeating a const does nothing } else { // For a non-const, we may need to generate an appropriate `Drop` - let value_operand = - unpack!(block = this.as_operand(block, scope, value, None, NeedsTemporary::No)); + let value_operand = unpack!( + block = this.as_operand(block, scope, value, LocalInfo::Boring, NeedsTemporary::No) + ); if let Operand::Move(to_drop) = value_operand { let success = this.cfg.start_new_block(); this.cfg.terminate( block, outer_source_info, - TerminatorKind::Drop { place: to_drop, target: success, unwind: None }, + TerminatorKind::Drop { + place: to_drop, + target: success, + unwind: UnwindAction::Continue, + }, ); this.diverge_from(block); block = success; } this.record_operands_moved(&[value_operand]); } - block.and(Rvalue::Aggregate(Box::new(AggregateKind::Array(elem_ty)), Vec::new())) + block.and(Rvalue::Aggregate(Box::new(AggregateKind::Array(elem_ty)), IndexVec::new())) } fn limit_capture_mutability( |