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saethlinsaethlin
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Move alignment checks to codegen
1 parent f5ca57e commit 9fc6dde

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40 files changed

+223
-234
lines changed

40 files changed

+223
-234
lines changed

‎compiler/rustc_borrowck/src/invalidation.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -205,7 +205,8 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
205205
| TerminatorKind::UnwindTerminate(_)
206206
| TerminatorKind::Unreachable
207207
| TerminatorKind::FalseEdge { real_target: _, imaginary_target: _ }
208-
| TerminatorKind::FalseUnwind { real_target: _, unwind: _ } => {
208+
| TerminatorKind::FalseUnwind { real_target: _, unwind: _ }
209+
| TerminatorKind::UbCheck { .. } => {
209210
// no data used, thus irrelevant to borrowck
210211
}
211212
}

‎compiler/rustc_borrowck/src/lib.rs

+4-2
Original file line numberDiff line numberDiff line change
@@ -785,7 +785,8 @@ impl<'cx, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx, R> for MirBorro
785785
| TerminatorKind::Return
786786
| TerminatorKind::CoroutineDrop
787787
| TerminatorKind::FalseEdge { real_target: _, imaginary_target: _ }
788-
| TerminatorKind::FalseUnwind { real_target: _, unwind: _ } => {
788+
| TerminatorKind::FalseUnwind { real_target: _, unwind: _ }
789+
| TerminatorKind::UbCheck { .. } => {
789790
// no data used, thus irrelevant to borrowck
790791
}
791792
}
@@ -835,7 +836,8 @@ impl<'cx, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx, R> for MirBorro
835836
| TerminatorKind::Goto { .. }
836837
| TerminatorKind::SwitchInt { .. }
837838
| TerminatorKind::Unreachable
838-
| TerminatorKind::InlineAsm { .. } => {}
839+
| TerminatorKind::InlineAsm { .. }
840+
| TerminatorKind::UbCheck { .. } => {}
839841
}
840842
}
841843
}

‎compiler/rustc_borrowck/src/type_check/mod.rs

+5-1
Original file line numberDiff line numberDiff line change
@@ -1358,7 +1358,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
13581358
| TerminatorKind::Drop { .. }
13591359
| TerminatorKind::FalseEdge { .. }
13601360
| TerminatorKind::FalseUnwind { .. }
1361-
| TerminatorKind::InlineAsm { .. } => {
1361+
| TerminatorKind::InlineAsm { .. }
1362+
| TerminatorKind::UbCheck { .. } => {
13621363
// no checks needed for these
13631364
}
13641365

@@ -1690,6 +1691,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
16901691
}
16911692
self.assert_iscleanup_unwind(body, block_data, unwind, is_cleanup);
16921693
}
1694+
TerminatorKind::UbCheck { target, .. } => {
1695+
self.assert_iscleanup(body, block_data, target, is_cleanup)
1696+
}
16931697
}
16941698
}
16951699

‎compiler/rustc_codegen_cranelift/src/base.rs

+5-12
Original file line numberDiff line numberDiff line change
@@ -356,18 +356,6 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
356356
source_info.span,
357357
);
358358
}
359-
AssertKind::MisalignedPointerDereference { ref required, ref found } => {
360-
let required = codegen_operand(fx, required).load_scalar(fx);
361-
let found = codegen_operand(fx, found).load_scalar(fx);
362-
let location = fx.get_caller_location(source_info).load_scalar(fx);
363-
364-
codegen_panic_inner(
365-
fx,
366-
rustc_hir::LangItem::PanicMisalignedPointerDereference,
367-
&[required, found, location],
368-
source_info.span,
369-
);
370-
}
371359
_ => {
372360
let msg_str = msg.description();
373361
codegen_panic(fx, msg_str, source_info);
@@ -488,6 +476,11 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
488476
let target_block = fx.get_block(*target);
489477
fx.bcx.ins().jump(target_block, &[]);
490478
}
479+
// FIXME
480+
TerminatorKind::UbCheck { target, kind: UbCheckKind::PointerAlignment { pointer } } => {
481+
let block = fx.get_block(*target);
482+
fx.bcx.ins().jump(block, &[]);
483+
}
491484
};
492485
}
493486
}

‎compiler/rustc_codegen_cranelift/src/constant.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -508,7 +508,8 @@ pub(crate) fn mir_operand_get_const_val<'tcx>(
508508
| TerminatorKind::Return
509509
| TerminatorKind::Unreachable
510510
| TerminatorKind::Drop { .. }
511-
| TerminatorKind::Assert { .. } => {}
511+
| TerminatorKind::Assert { .. }
512+
| TerminatorKind::UbCheck { .. } => {}
512513
TerminatorKind::Yield { .. }
513514
| TerminatorKind::CoroutineDrop
514515
| TerminatorKind::FalseEdge { .. }

‎compiler/rustc_codegen_ssa/src/mir/analyze.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -277,7 +277,8 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKi
277277
| TerminatorKind::SwitchInt { .. }
278278
| TerminatorKind::Yield { .. }
279279
| TerminatorKind::FalseEdge { .. }
280-
| TerminatorKind::FalseUnwind { .. } => { /* nothing to do */ }
280+
| TerminatorKind::FalseUnwind { .. }
281+
| TerminatorKind::UbCheck { .. } => { /* nothing to do */ }
281282
TerminatorKind::Call { unwind, .. }
282283
| TerminatorKind::InlineAsm { unwind, .. }
283284
| TerminatorKind::Assert { unwind, .. }

‎compiler/rustc_codegen_ssa/src/mir/block.rs

+79-8
Original file line numberDiff line numberDiff line change
@@ -12,7 +12,7 @@ use crate::MemFlags;
1212
use rustc_ast as ast;
1313
use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
1414
use rustc_hir::lang_items::LangItem;
15-
use rustc_middle::mir::{self, AssertKind, SwitchTargets, UnwindTerminateReason};
15+
use rustc_middle::mir::{self, AssertKind, SwitchTargets, UbCheckKind, UnwindTerminateReason};
1616
use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, ValidityRequirement};
1717
use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths};
1818
use rustc_middle::ty::{self, Instance, Ty};
@@ -616,13 +616,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
616616
// and `#[track_caller]` adds an implicit third argument.
617617
(LangItem::PanicBoundsCheck, vec![index, len, location])
618618
}
619-
AssertKind::MisalignedPointerDereference { ref required, ref found } => {
620-
let required = self.codegen_operand(bx, required).immediate();
621-
let found = self.codegen_operand(bx, found).immediate();
622-
// It's `fn panic_misaligned_pointer_dereference(required: usize, found: usize)`,
623-
// and `#[track_caller]` adds an implicit third argument.
624-
(LangItem::PanicMisalignedPointerDereference, vec![required, found, location])
625-
}
626619
_ => {
627620
let msg = bx.const_str(msg.description());
628621
// It's `pub fn panic(expr: &str)`, with the wide reference being passed
@@ -736,6 +729,79 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
736729
}
737730
}
738731

732+
fn codegen_alignment_check(
733+
&mut self,
734+
helper: &TerminatorCodegenHelper<'tcx>,
735+
bx: &mut Bx,
736+
pointer: &mir::Operand<'tcx>,
737+
source_info: mir::SourceInfo,
738+
target: mir::BasicBlock,
739+
) -> MergingSucc {
740+
let span = source_info.span;
741+
let pointer = self.codegen_operand(bx, pointer);
742+
let pointee_ty = pointer.layout.ty.builtin_deref(true).unwrap();
743+
let pointee_layout = bx.layout_of(pointee_ty.ty);
744+
745+
let mk_usize = |v: u64| {
746+
let layout = bx.layout_of(bx.tcx().types.usize);
747+
let rustc_target::abi::Abi::Scalar(abi) = layout.abi else { unreachable!() };
748+
let v = rustc_middle::mir::interpret::Scalar::from_target_usize(v, &bx.tcx());
749+
bx.scalar_to_backend(v, abi, bx.cx().type_isize())
750+
};
751+
752+
let align = pointee_layout.align.abi.bytes();
753+
let mask = mk_usize(align - 1);
754+
let zero = mk_usize(0);
755+
let required = mk_usize(align);
756+
757+
let ptr_imm = match pointer.val {
758+
crate::mir::OperandValue::Immediate(imm) => imm,
759+
crate::mir::OperandValue::Pair(ptr, _) => ptr,
760+
_ => {
761+
unreachable!("{pointer:?}");
762+
}
763+
};
764+
let int_imm = bx.ptrtoint(ptr_imm, bx.cx().type_isize());
765+
766+
let masked = bx.and(int_imm, mask);
767+
768+
let is_zero = bx.icmp(
769+
crate::base::bin_op_to_icmp_predicate(mir::BinOp::Eq.to_hir_binop(), false),
770+
masked,
771+
zero,
772+
);
773+
774+
let lltarget = helper.llbb_with_cleanup(self, target);
775+
let panic_block = bx.append_sibling_block("panic");
776+
777+
bx.cond_br(is_zero, lltarget, panic_block);
778+
779+
bx.switch_to_block(panic_block);
780+
self.set_debug_loc(bx, source_info);
781+
782+
let location = self.get_caller_location(bx, source_info).immediate();
783+
784+
let found = int_imm;
785+
786+
let (lang_item, args) =
787+
(LangItem::PanicMisalignedPointerDereference, vec![required, found, location]);
788+
789+
let (fn_abi, llfn) = common::build_langcall(bx, Some(span), lang_item);
790+
let merging_succ = helper.do_call(
791+
self,
792+
bx,
793+
fn_abi,
794+
llfn,
795+
&args,
796+
None,
797+
mir::UnwindAction::Unreachable,
798+
&[],
799+
false,
800+
);
801+
assert_eq!(merging_succ, MergingSucc::False);
802+
MergingSucc::False
803+
}
804+
739805
fn codegen_call_terminator(
740806
&mut self,
741807
helper: TerminatorCodegenHelper<'tcx>,
@@ -1291,6 +1357,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
12911357
self.instance,
12921358
mergeable_succ(),
12931359
),
1360+
1361+
mir::TerminatorKind::UbCheck {
1362+
target,
1363+
kind: UbCheckKind::PointerAlignment { ref pointer },
1364+
} => self.codegen_alignment_check(&helper, bx, pointer, terminator.source_info, target),
12941365
}
12951366
}
12961367

‎compiler/rustc_const_eval/src/const_eval/machine.rs

-6
Original file line numberDiff line numberDiff line change
@@ -555,12 +555,6 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
555555
RemainderByZero(op) => RemainderByZero(eval_to_int(op)?),
556556
ResumedAfterReturn(coroutine_kind) => ResumedAfterReturn(*coroutine_kind),
557557
ResumedAfterPanic(coroutine_kind) => ResumedAfterPanic(*coroutine_kind),
558-
MisalignedPointerDereference { ref required, ref found } => {
559-
MisalignedPointerDereference {
560-
required: eval_to_int(required)?,
561-
found: eval_to_int(found)?,
562-
}
563-
}
564558
};
565559
Err(ConstEvalErrKind::AssertFailure(err).into())
566560
}

‎compiler/rustc_const_eval/src/interpret/terminator.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -85,7 +85,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
8585
self.pop_stack_frame(/* unwinding */ false)?
8686
}
8787

88-
Goto { target } => self.go_to_block(target),
88+
Goto { target } | UbCheck { target, .. } => self.go_to_block(target),
8989

9090
SwitchInt { ref discr, ref targets } => {
9191
let discr = self.read_immediate(&self.eval_operand(discr, None)?)?;

‎compiler/rustc_const_eval/src/transform/check_consts/check.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -1058,7 +1058,8 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
10581058
| TerminatorKind::UnwindResume
10591059
| TerminatorKind::Return
10601060
| TerminatorKind::SwitchInt { .. }
1061-
| TerminatorKind::Unreachable => {}
1061+
| TerminatorKind::Unreachable
1062+
| TerminatorKind::UbCheck { .. } => {}
10621063
}
10631064
}
10641065
}

‎compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -118,7 +118,8 @@ impl<'tcx> Visitor<'tcx> for CheckLiveDrops<'_, 'tcx> {
118118
| mir::TerminatorKind::Return
119119
| mir::TerminatorKind::SwitchInt { .. }
120120
| mir::TerminatorKind::Unreachable
121-
| mir::TerminatorKind::Yield { .. } => {}
121+
| mir::TerminatorKind::Yield { .. }
122+
| mir::TerminatorKind::UbCheck { .. } => {}
122123
}
123124
}
124125
}

‎compiler/rustc_const_eval/src/transform/validate.rs

+3-2
Original file line numberDiff line numberDiff line change
@@ -393,7 +393,7 @@ impl<'a, 'tcx> Visitor<'tcx> for CfgChecker<'a, 'tcx> {
393393

394394
fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
395395
match &terminator.kind {
396-
TerminatorKind::Goto { target } => {
396+
TerminatorKind::Goto { target } | TerminatorKind::UbCheck { target, .. } => {
397397
self.check_edge(location, *target, EdgeKind::Normal);
398398
}
399399
TerminatorKind::SwitchInt { targets, discr: _ } => {
@@ -1298,7 +1298,8 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
12981298
| TerminatorKind::UnwindResume
12991299
| TerminatorKind::UnwindTerminate(_)
13001300
| TerminatorKind::Return
1301-
| TerminatorKind::Unreachable => {}
1301+
| TerminatorKind::Unreachable
1302+
| TerminatorKind::UbCheck { .. } => {}
13021303
}
13031304

13041305
self.super_terminator(terminator, location);

‎compiler/rustc_middle/messages.ftl

-3
Original file line numberDiff line numberDiff line change
@@ -14,9 +14,6 @@ middle_assert_divide_by_zero =
1414
1515
middle_assert_gen_resume_after_panic = `gen` fn or block cannot be further iterated on after it panicked
1616
17-
middle_assert_misaligned_ptr_deref =
18-
misaligned pointer dereference: address must be a multiple of {$required} but is {$found}
19-
2017
middle_assert_op_overflow =
2118
attempt to compute `{$left} {$op} {$right}`, which would overflow
2219

‎compiler/rustc_middle/src/mir/pretty.rs

+4-1
Original file line numberDiff line numberDiff line change
@@ -858,6 +858,9 @@ impl<'tcx> TerminatorKind<'tcx> {
858858
}
859859
write!(fmt, ", options({options:?}))")
860860
}
861+
UbCheck { target: _, kind: UbCheckKind::PointerAlignment { pointer } } => {
862+
write!(fmt, "pointer_alignment_check({pointer:?})")
863+
}
861864
}
862865
}
863866

@@ -866,7 +869,7 @@ impl<'tcx> TerminatorKind<'tcx> {
866869
use self::TerminatorKind::*;
867870
match *self {
868871
Return | UnwindResume | UnwindTerminate(_) | Unreachable | CoroutineDrop => vec![],
869-
Goto { .. } => vec!["".into()],
872+
Goto { .. } | UbCheck { .. } => vec!["".into()],
870873
SwitchInt { ref targets, .. } => targets
871874
.values
872875
.iter()

‎compiler/rustc_middle/src/mir/syntax.rs

+21-3
Original file line numberDiff line numberDiff line change
@@ -588,7 +588,9 @@ impl CallSource {
588588
#[derive(Clone, TyEncodable, TyDecodable, Hash, HashStable, PartialEq, TypeFoldable, TypeVisitable)]
589589
pub enum TerminatorKind<'tcx> {
590590
/// Block has one successor; we continue execution there.
591-
Goto { target: BasicBlock },
591+
Goto {
592+
target: BasicBlock,
593+
},
592594

593595
/// Switches based on the computed value.
594596
///
@@ -655,7 +657,12 @@ pub enum TerminatorKind<'tcx> {
655657
/// The `replace` flag indicates whether this terminator was created as part of an assignment.
656658
/// This should only be used for diagnostic purposes, and does not have any operational
657659
/// meaning.
658-
Drop { place: Place<'tcx>, target: BasicBlock, unwind: UnwindAction, replace: bool },
660+
Drop {
661+
place: Place<'tcx>,
662+
target: BasicBlock,
663+
unwind: UnwindAction,
664+
replace: bool,
665+
},
659666

660667
/// Roughly speaking, evaluates the `func` operand and the arguments, and starts execution of
661668
/// the referred to function. The operand types must match the argument types of the function.
@@ -798,6 +805,17 @@ pub enum TerminatorKind<'tcx> {
798805
/// if and only if InlineAsmOptions::MAY_UNWIND is set.
799806
unwind: UnwindAction,
800807
},
808+
809+
UbCheck {
810+
target: BasicBlock,
811+
kind: UbCheckKind<'tcx>,
812+
},
813+
}
814+
815+
#[derive(Clone, TyEncodable, TyDecodable, Hash, HashStable, PartialEq, TypeFoldable, TypeVisitable)]
816+
#[derive(Debug)]
817+
pub enum UbCheckKind<'tcx> {
818+
PointerAlignment { pointer: Operand<'tcx> },
801819
}
802820

803821
impl TerminatorKind<'_> {
@@ -819,6 +837,7 @@ impl TerminatorKind<'_> {
819837
TerminatorKind::FalseEdge { .. } => "FalseEdge",
820838
TerminatorKind::FalseUnwind { .. } => "FalseUnwind",
821839
TerminatorKind::InlineAsm { .. } => "InlineAsm",
840+
TerminatorKind::UbCheck { .. } => "UbCheck",
822841
}
823842
}
824843
}
@@ -885,7 +904,6 @@ pub enum AssertKind<O> {
885904
RemainderByZero(O),
886905
ResumedAfterReturn(CoroutineKind),
887906
ResumedAfterPanic(CoroutineKind),
888-
MisalignedPointerDereference { required: O, found: O },
889907
}
890908

891909
#[derive(Clone, Debug, PartialEq, TyEncodable, TyDecodable, Hash, HashStable)]

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