diff options
15 files changed, 135 insertions, 128 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs index 88d25be6bd8..0604d5ee6fa 100644 --- a/compiler/rustc_const_eval/src/interpret/machine.rs +++ b/compiler/rustc_const_eval/src/interpret/machine.rs @@ -373,9 +373,21 @@ pub trait Machine<'mir, 'tcx>: Sized { Ok(()) } - /// Executes a retagging operation. + /// Executes a retagging operation for a single pointer. + /// Returns the possibly adjusted pointer. #[inline] - fn retag( + fn retag_ptr_value( + _ecx: &mut InterpCx<'mir, 'tcx, Self>, + _kind: mir::RetagKind, + val: &ImmTy<'tcx, Self::Provenance>, + ) -> InterpResult<'tcx, ImmTy<'tcx, Self::Provenance>> { + Ok(val.clone()) + } + + /// Executes a retagging operation on a compound value. + /// Replaces all pointers stored in the given place. + #[inline] + fn retag_place_contents( _ecx: &mut InterpCx<'mir, 'tcx, Self>, _kind: mir::RetagKind, _place: &PlaceTy<'tcx, Self::Provenance>, diff --git a/compiler/rustc_const_eval/src/interpret/step.rs b/compiler/rustc_const_eval/src/interpret/step.rs index 60578246eed..81b44a49484 100644 --- a/compiler/rustc_const_eval/src/interpret/step.rs +++ b/compiler/rustc_const_eval/src/interpret/step.rs @@ -8,7 +8,7 @@ use rustc_middle::mir; use rustc_middle::mir::interpret::{InterpResult, Scalar}; use rustc_middle::ty::layout::LayoutOf; -use super::{InterpCx, Machine}; +use super::{ImmTy, InterpCx, Machine}; /// Classify whether an operator is "left-homogeneous", i.e., the LHS has the /// same type as the result. @@ -108,7 +108,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { // Stacked Borrows. Retag(kind, place) => { let dest = self.eval_place(**place)?; - M::retag(self, *kind, &dest)?; + M::retag_place_contents(self, *kind, &dest)?; } Intrinsic(box ref intrinsic) => self.emulate_nondiverging_intrinsic(intrinsic)?, @@ -247,10 +247,41 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { self.write_scalar(Scalar::from_machine_usize(len, self), &dest)?; } - AddressOf(_, place) | Ref(_, _, place) => { + Ref(_, borrow_kind, place) => { let src = self.eval_place(place)?; let place = self.force_allocation(&src)?; - self.write_immediate(place.to_ref(self), &dest)?; + let val = ImmTy::from_immediate(place.to_ref(self), dest.layout); + // A fresh reference was created, make sure it gets retagged. + let val = M::retag_ptr_value( + self, + if borrow_kind.allows_two_phase_borrow() { + mir::RetagKind::TwoPhase + } else { + mir::RetagKind::Default + }, + &val, + )?; + self.write_immediate(*val, &dest)?; + } + + AddressOf(_, place) => { + // Figure out whether this is an addr_of of an already raw place. + let place_base_raw = if place.has_deref() { + let ty = self.frame().body.local_decls[place.local].ty; + ty.is_unsafe_ptr() + } else { + // Not a deref, and thus not raw. + false + }; + + let src = self.eval_place(place)?; + let place = self.force_allocation(&src)?; + let mut val = ImmTy::from_immediate(place.to_ref(self), dest.layout); + if !place_base_raw { + // If this was not already raw, it needs retagging. + val = M::retag_ptr_value(self, mir::RetagKind::Raw, &val)?; + } + self.write_immediate(*val, &dest)?; } NullaryOp(null_op, ty) => { diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs index 7d2a6bda569..614e0d012b3 100644 --- a/compiler/rustc_middle/src/mir/syntax.rs +++ b/compiler/rustc_middle/src/mir/syntax.rs @@ -400,7 +400,7 @@ impl std::fmt::Display for NonDivergingIntrinsic<'_> { #[derive(Copy, Clone, TyEncodable, TyDecodable, Debug, PartialEq, Eq, Hash, HashStable)] #[rustc_pass_by_value] pub enum RetagKind { - /// The initial retag when entering a function. + /// The initial retag of arguments when entering a function. FnEntry, /// Retag preparing for a two-phase borrow. TwoPhase, diff --git a/compiler/rustc_mir_transform/src/add_retag.rs b/compiler/rustc_mir_transform/src/add_retag.rs index 036b5589849..3d22035f078 100644 --- a/compiler/rustc_mir_transform/src/add_retag.rs +++ b/compiler/rustc_mir_transform/src/add_retag.rs @@ -10,16 +10,6 @@ use rustc_middle::ty::{self, Ty, TyCtxt}; pub struct AddRetag; -/// Determines whether this place is "stable": Whether, if we evaluate it again -/// after the assignment, we can be sure to obtain the same place value. -/// (Concurrent accesses by other threads are no problem as these are anyway non-atomic -/// copies. Data races are UB.) -fn is_stable(place: PlaceRef<'_>) -> bool { - // Which place this evaluates to can change with any memory write, - // so cannot assume deref to be stable. - !place.has_deref() -} - /// Determine whether this type may contain a reference (or box), and thus needs retagging. /// We will only recurse `depth` times into Tuples/ADTs to bound the cost of this. fn may_contain_reference<'tcx>(ty: Ty<'tcx>, depth: u32, tcx: TyCtxt<'tcx>) -> bool { @@ -69,22 +59,10 @@ impl<'tcx> MirPass<'tcx> for AddRetag { let basic_blocks = body.basic_blocks.as_mut(); let local_decls = &body.local_decls; let needs_retag = |place: &Place<'tcx>| { - // FIXME: Instead of giving up for unstable places, we should introduce - // a temporary and retag on that. - is_stable(place.as_ref()) + !place.has_deref() // we're not eally interested in stores to "outside" locations, they are hard to keep track of anyway && may_contain_reference(place.ty(&*local_decls, tcx).ty, /*depth*/ 3, tcx) && !local_decls[place.local].is_deref_temp() }; - let place_base_raw = |place: &Place<'tcx>| { - // If this is a `Deref`, get the type of what we are deref'ing. - if place.has_deref() { - let ty = &local_decls[place.local].ty; - ty.is_unsafe_ptr() - } else { - // Not a deref, and thus not raw. - false - } - }; // PART 1 // Retag arguments at the beginning of the start block. @@ -108,7 +86,7 @@ impl<'tcx> MirPass<'tcx> for AddRetag { } // PART 2 - // Retag return values of functions. Also escape-to-raw the argument of `drop`. + // Retag return values of functions. // We collect the return destinations because we cannot mutate while iterating. let returns = basic_blocks .iter_mut() @@ -140,30 +118,25 @@ impl<'tcx> MirPass<'tcx> for AddRetag { } // PART 3 - // Add retag after assignment. + // Add retag after assignments where data "enters" this function: the RHS is behind a deref and the LHS is not. for block_data in basic_blocks { // We want to insert statements as we iterate. To this end, we // iterate backwards using indices. for i in (0..block_data.statements.len()).rev() { let (retag_kind, place) = match block_data.statements[i].kind { - // Retag-as-raw after escaping to a raw pointer, if the referent - // is not already a raw pointer. - StatementKind::Assign(box (lplace, Rvalue::AddressOf(_, ref rplace))) - if !place_base_raw(rplace) => - { - (RetagKind::Raw, lplace) - } // Retag after assignments of reference type. StatementKind::Assign(box (ref place, ref rvalue)) if needs_retag(place) => { - let kind = match rvalue { - Rvalue::Ref(_, borrow_kind, _) - if borrow_kind.allows_two_phase_borrow() => - { - RetagKind::TwoPhase - } - _ => RetagKind::Default, + let add_retag = match rvalue { + // Ptr-creating operations already do their own internal retagging, no + // need to also add a retag statement. + Rvalue::Ref(..) | Rvalue::AddressOf(..) => false, + _ => true, }; - (kind, *place) + if add_retag { + (RetagKind::Default, *place) + } else { + continue; + } } // Do nothing for the rest _ => continue, diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs index 8922298ecaf..69f96fe48ea 100644 --- a/compiler/rustc_mir_transform/src/generator.rs +++ b/compiler/rustc_mir_transform/src/generator.rs @@ -985,16 +985,6 @@ fn create_generator_drop_shim<'tcx>( tcx.mk_ptr(ty::TypeAndMut { ty: gen_ty, mutbl: hir::Mutability::Mut }), source_info, ); - if tcx.sess.opts.unstable_opts.mir_emit_retag { - // Alias tracking must know we changed the type - body.basic_blocks_mut()[START_BLOCK].statements.insert( - 0, - Statement { - source_info, - kind: StatementKind::Retag(RetagKind::Raw, Box::new(Place::from(SELF_ARG))), - }, - ) - } // Make sure we remove dead blocks to remove // unrelated code from the resume part of the function diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs index a115bb2831a..16b7dcad17e 100644 --- a/compiler/rustc_mir_transform/src/shim.rs +++ b/compiler/rustc_mir_transform/src/shim.rs @@ -177,16 +177,6 @@ fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) if ty.is_some() { // The first argument (index 0), but add 1 for the return value. let dropee_ptr = Place::from(Local::new(1 + 0)); - if tcx.sess.opts.unstable_opts.mir_emit_retag { - // Function arguments should be retagged, and we make this one raw. - body.basic_blocks_mut()[START_BLOCK].statements.insert( - 0, - Statement { - source_info, - kind: StatementKind::Retag(RetagKind::Raw, Box::new(dropee_ptr)), - }, - ); - } let patch = { let param_env = tcx.param_env_reveal_all_normalized(def_id); let mut elaborator = diff --git a/src/test/mir-opt/inline/inline_retag.bar.Inline.after.mir b/src/test/mir-opt/inline/inline_retag.bar.Inline.after.mir index 75af20d482d..60149ff3606 100644 --- a/src/test/mir-opt/inline/inline_retag.bar.Inline.after.mir +++ b/src/test/mir-opt/inline/inline_retag.bar.Inline.after.mir @@ -38,9 +38,7 @@ fn bar() -> bool { // + literal: Const { ty: &i32, val: Unevaluated(bar, [], Some(promoted[1])) } Retag(_10); // scope 1 at $DIR/inline_retag.rs:+2:7: +2:9 _4 = &(*_10); // scope 1 at $DIR/inline_retag.rs:+2:7: +2:9 - Retag(_4); // scope 1 at $DIR/inline_retag.rs:+2:7: +2:9 _3 = &(*_4); // scope 1 at $DIR/inline_retag.rs:+2:7: +2:9 - Retag(_3); // scope 1 at $DIR/inline_retag.rs:+2:7: +2:9 StorageLive(_6); // scope 1 at $DIR/inline_retag.rs:+2:11: +2:14 StorageLive(_7); // scope 1 at $DIR/inline_retag.rs:+2:11: +2:14 _9 = const _; // scope 1 at $DIR/inline_retag.rs:+2:11: +2:14 @@ -49,9 +47,7 @@ fn bar() -> bool { // + literal: Const { ty: &i32, val: Unevaluated(bar, [], Some(promoted[0])) } Retag(_9); // scope 1 at $DIR/inline_retag.rs:+2:11: +2:14 _7 = &(*_9); // scope 1 at $DIR/inline_retag.rs:+2:11: +2:14 - Retag(_7); // scope 1 at $DIR/inline_retag.rs:+2:11: +2:14 _6 = &(*_7); // scope 1 at $DIR/inline_retag.rs:+2:11: +2:14 - Retag(_6); // scope 1 at $DIR/inline_retag.rs:+2:11: +2:14 Retag(_3); // scope 2 at $DIR/inline_retag.rs:16:8: 16:9 Retag(_6); // scope 2 at $DIR/inline_retag.rs:16:17: 16:18 StorageLive(_11); // scope 2 at $DIR/inline_retag.rs:17:5: 17:7 diff --git a/src/test/mir-opt/retag.array_casts.SimplifyCfg-elaborate-drops.after.mir b/src/test/mir-opt/retag.array_casts.SimplifyCfg-elaborate-drops.after.mir index fe57e32a7ac..7b69b3e07d6 100644 --- a/src/test/mir-opt/retag.array_casts.SimplifyCfg-elaborate-drops.after.mir +++ b/src/test/mir-opt/retag.array_casts.SimplifyCfg-elaborate-drops.after.mir @@ -68,9 +68,7 @@ fn array_casts() -> () { StorageLive(_3); // scope 1 at $DIR/retag.rs:+2:13: +2:19 StorageLive(_4); // scope 1 at $DIR/retag.rs:+2:13: +2:19 _4 = &mut _1; // scope 1 at $DIR/retag.rs:+2:13: +2:19 - Retag(_4); // scope 1 at $DIR/retag.rs:+2:13: +2:19 _3 = &raw mut (*_4); // scope 1 at $DIR/retag.rs:+2:13: +2:19 - Retag([raw] _3); // scope 1 at $DIR/retag.rs:+2:13: +2:19 _2 = move _3 as *mut usize (Pointer(ArrayToPointer)); // scope 1 at $DIR/retag.rs:+2:13: +2:33 StorageDead(_3); // scope 1 at $DIR/retag.rs:+2:32: +2:33 StorageDead(_4); // scope 1 at $DIR/retag.rs:+2:33: +2:34 @@ -96,9 +94,7 @@ fn array_casts() -> () { StorageLive(_10); // scope 4 at $DIR/retag.rs:+6:13: +6:15 StorageLive(_11); // scope 4 at $DIR/retag.rs:+6:13: +6:15 _11 = &_8; // scope 4 at $DIR/retag.rs:+6:13: +6:15 - Retag(_11); // scope 4 at $DIR/retag.rs:+6:13: +6:15 _10 = &raw const (*_11); // scope 4 at $DIR/retag.rs:+6:13: +6:15 - Retag([raw] _10); // scope 4 at $DIR/retag.rs:+6:13: +6:15 _9 = move _10 as *const usize (Pointer(ArrayToPointer)); // scope 4 at $DIR/retag.rs:+6:13: +6:31 StorageDead(_10); // scope 4 at $DIR/retag.rs:+6:30: +6:31 StorageDead(_11); // scope 4 at $DIR/retag.rs:+6:31: +6:32 @@ -119,7 +115,6 @@ fn array_casts() -> () { StorageDead(_17); // scope 6 at $DIR/retag.rs:+7:33: +7:34 _15 = (*_16); // scope 6 at $DIR/retag.rs:+7:25: +7:34 _14 = &_15; // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL - Retag(_14); // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL StorageLive(_18); // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL _35 = const _; // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL // mir::Constant @@ -127,7 +122,6 @@ fn array_casts() -> () { // + literal: Const { ty: &usize, val: Unevaluated(array_casts, [], Some(promoted[0])) } Retag(_35); // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL _18 = &(*_35); // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL - Retag(_18); // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL Deinit(_13); // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL (_13.0: &usize) = move _14; // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL (_13.1: &usize) = move _18; // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL @@ -164,15 +158,11 @@ fn array_casts() -> () { StorageLive(_30); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL StorageLive(_31); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL _31 = &(*_20); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL - Retag(_31); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL _30 = &(*_31); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL - Retag(_30); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL StorageLive(_32); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL StorageLive(_33); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL _33 = &(*_21); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL - Retag(_33); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL _32 = &(*_33); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL - Retag(_32); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL StorageLive(_34); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL Deinit(_34); // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL discriminant(_34) = 0; // scope 8 at $SRC_DIR/core/src/macros/mod.rs:LL:COL diff --git a/src/test/mir-opt/retag.core.ptr-drop_in_place.Test.SimplifyCfg-make_shim.after.mir b/src/test/mir-opt/retag.core.ptr-drop_in_place.Test.SimplifyCfg-make_shim.after.mir index cdc413c568f..14f297e948b 100644 --- a/src/test/mir-opt/retag.core.ptr-drop_in_place.Test.SimplifyCfg-make_shim.after.mir +++ b/src/test/mir-opt/retag.core.ptr-drop_in_place.Test.SimplifyCfg-make_shim.after.mir @@ -6,7 +6,6 @@ fn std::ptr::drop_in_place(_1: *mut Test) -> () { let mut _3: (); // in scope 0 at $SRC_DIR/core/src/ptr/mod.rs:+0:1: +0:56 bb0: { - Retag([raw] _1); // scope 0 at $SRC_DIR/core/src/ptr/mod.rs:+0:1: +0:56 _2 = &mut (*_1); // scope 0 at $SRC_DIR/core/src/ptr/mod.rs:+0:1: +0:56 _3 = <Test as Drop>::drop(move _2) -> bb1; // scope 0 at $SRC_DIR/core/src/ptr/mod.rs:+0:1: +0:56 // mir::Constant diff --git a/src/test/mir-opt/retag.main-{closure#0}.SimplifyCfg-elaborate-drops.after.mir b/src/test/mir-opt/retag.main-{closure#0}.SimplifyCfg-elaborate-drops.after.mir index 96fc7e6493a..9e5c119a2b2 100644 --- a/src/test/mir-opt/retag.main-{closure#0}.SimplifyCfg-elaborate-drops.after.mir +++ b/src/test/mir-opt/retag.main-{closure#0}.SimplifyCfg-elaborate-drops.after.mir @@ -15,7 +15,6 @@ fn main::{closure#0}(_1: &[closure@main::{closure#0}], _2: &i32) -> &i32 { _3 = _2; // scope 0 at $DIR/retag.rs:+1:18: +1:19 Retag(_3); // scope 0 at $DIR/retag.rs:+1:18: +1:19 _0 = &(*_2); // scope 1 at $DIR/retag.rs:+2:9: +2:10 - Retag(_0); // scope 1 at $DIR/retag.rs:+2:9: +2:10 StorageDead(_3); // scope 0 at $DIR/retag.rs:+3:5: +3:6 return; // scope 0 at $DIR/retag.rs:+3:6: +3:6 } diff --git a/src/test/mir-opt/retag.main.SimplifyCfg-elaborate-drops.after.mir b/src/test/mir-opt/retag.main.SimplifyCfg-elaborate-drops.after.mir index 81225b44ebf..b853e450541 100644 --- a/src/test/mir-opt/retag.main.SimplifyCfg-elaborate-drops.after.mir +++ b/src/test/mir-opt/retag.main.SimplifyCfg-elaborate-drops.after.mir @@ -65,13 +65,10 @@ fn main() -> () { Deinit(_5); // scope 1 at $DIR/retag.rs:+3:17: +3:24 (_5.0: i32) = const 0_i32; // scope 1 at $DIR/retag.rs:+3:17: +3:24 _4 = &_5; // scope 1 at $DIR/retag.rs:+3:17: +3:36 - Retag(_4); // scope 1 at $DIR/retag.rs:+3:17: +3:36 StorageLive(_6); // scope 1 at $DIR/retag.rs:+3:29: +3:35 StorageLive(_7); // scope 1 at $DIR/retag.rs:+3:29: +3:35 _7 = &mut _1; // scope 1 at $DIR/retag.rs:+3:29: +3:35 - Retag(_7); // scope 1 at $DIR/retag.rs:+3:29: +3:35 _6 = &mut (*_7); // scope 1 at $DIR/retag.rs:+3:29: +3:35 - Retag([2phase] _6); // scope 1 at $DIR/retag.rs:+3:29: +3:35 _3 = Test::foo(move _4, move _6) -> [return: bb1, unwind: bb8]; // scope 1 at $DIR/retag.rs:+3:17: +3:36 // mir::Constant // + span: $DIR/retag.rs:33:25: 33:28 @@ -93,7 +90,6 @@ fn main() -> () { _9 = move _3; // scope 2 at $DIR/retag.rs:+4:19: +4:20 Retag(_9); // scope 2 at $DIR/retag.rs:+4:19: +4:20 _8 = &mut (*_9); // scope 2 at $DIR/retag.rs:+4:19: +4:20 - Retag(_8); // scope 2 at $DIR/retag.rs:+4:19: +4:20 StorageDead(_9); // scope 2 at $DIR/retag.rs:+4:22: +4:23 StorageLive(_10); // scope 3 at $DIR/retag.rs:+5:13: +5:14 _10 = move _8; // scope 3 at $DIR/retag.rs:+5:17: +5:18 @@ -101,7 +97,6 @@ fn main() -> () { StorageLive(_11); // scope 4 at $DIR/retag.rs:+7:13: +7:15 StorageLive(_12); // scope 4 at $DIR/retag.rs:+7:18: +7:29 _12 = &raw mut (*_10); // scope 4 at $DIR/retag.rs:+7:18: +7:19 - Retag([raw] _12); // scope 4 at $DIR/retag.rs:+7:18: +7:19 _11 = _12; // scope 4 at $DIR/retag.rs:+7:18: +7:29 StorageDead(_12); // scope 4 at $DIR/retag.rs:+7:29: +7:30 _2 = const (); // scope 1 at $DIR/retag.rs:+2:5: +8:6 @@ -122,9 +117,7 @@ fn main() -> () { StorageLive(_17); // scope 6 at $DIR/retag.rs:+15:16: +15:18 StorageLive(_18); // scope 6 at $DIR/retag.rs:+15:16: +15:18 _18 = &_1; // scope 6 at $DIR/retag.rs:+15:16: +15:18 - Retag(_18); // scope 6 at $DIR/retag.rs:+15:16: +15:18 _17 = &(*_18); // scope 6 at $DIR/retag.rs:+15:16: +15:18 - Retag(_17); // scope 6 at $DIR/retag.rs:+15:16: +15:18 _15 = move _16(move _17) -> bb3; // scope 6 at $DIR/retag.rs:+15:14: +15:19 } @@ -139,7 +132,6 @@ fn main() -> () { Deinit(_21); // scope 7 at $DIR/retag.rs:+18:5: +18:12 (_21.0: i32) = const 0_i32; // scope 7 at $DIR/retag.rs:+18:5: +18:12 _20 = &_21; // scope 7 at $DIR/retag.rs:+18:5: +18:24 - Retag(_20); // scope 7 at $DIR/retag.rs:+18:5: +18:24 StorageLive(_22); // scope 7 at $DIR/retag.rs:+18:21: +18:23 StorageLive(_23); // scope 7 at $DIR/retag.rs:+18:21: +18:23 _28 = const _; // scope 7 at $DIR/retag.rs:+18:21: +18:23 @@ -148,9 +140,7 @@ fn main() -> () { // + literal: Const { ty: &i32, val: Unevaluated(main, [], Some(promoted[0])) } Retag(_28); // scope 7 at $DIR/retag.rs:+18:21: +18:23 _23 = &(*_28); // scope 7 at $DIR/retag.rs:+18:21: +18:23 - Retag(_23); // scope 7 at $DIR/retag.rs:+18:21: +18:23 _22 = &(*_23); // scope 7 at $DIR/retag.rs:+18:21: +18:23 - Retag(_22); // scope 7 at $DIR/retag.rs:+18:21: +18:23 _19 = Test::foo_shr(move _20, move _22) -> [return: bb4, unwind: bb7]; // scope 7 at $DIR/retag.rs:+18:5: +18:24 // mir::Constant // + span: $DIR/retag.rs:48:13: 48:20 @@ -171,7 +161,6 @@ fn main() -> () { StorageLive(_25); // scope 7 at $DIR/retag.rs:+21:9: +21:11 StorageLive(_26); // scope 7 at $DIR/retag.rs:+21:14: +21:28 _26 = &raw const (*_15); // scope 7 at $DIR/retag.rs:+21:14: +21:16 - Retag([raw] _26); // scope 7 at $DIR/retag.rs:+21:14: +21:16 _25 = _26; // scope 7 at $DIR/retag.rs:+21:14: +21:28 StorageDead(_26); // scope 7 at $DIR/retag.rs:+21:28: +21:29 StorageLive(_27); // scope 8 at $DIR/retag.rs:+23:5: +23:18 diff --git a/src/test/mir-opt/retag.{impl#0}-foo.SimplifyCfg-elaborate-drops.after.mir b/src/test/mir-opt/retag.{impl#0}-foo.SimplifyCfg-elaborate-drops.after.mir index 08fd655ae29..4b50205fa80 100644 --- a/src/test/mir-opt/retag.{impl#0}-foo.SimplifyCfg-elaborate-drops.after.mir +++ b/src/test/mir-opt/retag.{impl#0}-foo.SimplifyCfg-elaborate-drops.after.mir @@ -11,9 +11,7 @@ fn <impl at $DIR/retag.rs:12:1: 12:10>::foo(_1: &Test, _2: &mut i32) -> &mut i32 Retag([fn entry] _2); // scope 0 at $DIR/retag.rs:+0:23: +0:24 StorageLive(_3); // scope 0 at $DIR/retag.rs:+1:9: +1:10 _3 = &mut (*_2); // scope 0 at $DIR/retag.rs:+1:9: +1:10 - Retag(_3); // scope 0 at $DIR/retag.rs:+1:9: +1:10 _0 = &mut (*_3); // scope 0 at $DIR/retag.rs:+1:9: +1:10 - Retag(_0); // scope 0 at $DIR/retag.rs:+1:9: +1:10 StorageDead(_3); // scope 0 at $DIR/retag.rs:+2:5: +2:6 return; // scope 0 at $DIR/retag.rs:+2:6: +2:6 } diff --git a/src/tools/miri/src/borrow_tracker/mod.rs b/src/tools/miri/src/borrow_tracker/mod.rs index 10e6e252e94..f896a337f42 100644 --- a/src/tools/miri/src/borrow_tracker/mod.rs +++ b/src/tools/miri/src/borrow_tracker/mod.rs @@ -11,7 +11,6 @@ use rustc_target::abi::Size; use crate::*; pub mod stacked_borrows; -use stacked_borrows::diagnostics::RetagCause; pub type CallId = NonZeroU64; @@ -265,11 +264,19 @@ impl GlobalStateInner { impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {} pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { - fn retag(&mut self, kind: RetagKind, place: &PlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> { + fn retag_ptr_value(&mut self, kind: RetagKind, val: &ImmTy<'tcx, Provenance>) -> InterpResult<'tcx, ImmTy<'tcx, Provenance>> { let this = self.eval_context_mut(); let method = this.machine.borrow_tracker.as_ref().unwrap().borrow().borrow_tracker_method; match method { - BorrowTrackerMethod::StackedBorrows => this.sb_retag(kind, place), + BorrowTrackerMethod::StackedBorrows => this.sb_retag_ptr_value(kind, val), + } + } + + fn retag_place_contents(&mut self, kind: RetagKind, place: &PlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> { + let this = self.eval_context_mut(); + let method = this.machine.borrow_tracker.as_ref().unwrap().borrow().borrow_tracker_method; + match method { + BorrowTrackerMethod::StackedBorrows => this.sb_retag_place_contents(kind, place), } } diff --git a/src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs b/src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs index bcac873251f..04298d435b7 100644 --- a/src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs +++ b/src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs @@ -1,6 +1,10 @@ //! Implements "Stacked Borrows". See <https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md> //! for further information. +mod item; +mod stack; +pub mod diagnostics; + use log::trace; use std::cmp; use std::fmt::{self, Write}; @@ -15,15 +19,13 @@ use rustc_target::abi::{Abi, Size}; use crate::borrow_tracker::{ stacked_borrows::diagnostics::{AllocHistory, DiagnosticCx, DiagnosticCxBuilder, TagHistory}, - AccessKind, GlobalStateInner, ProtectorKind, RetagCause, RetagFields, + AccessKind, GlobalStateInner, ProtectorKind, RetagFields, }; use crate::*; -mod item; pub use item::{Item, Permission}; -mod stack; pub use stack::Stack; -pub mod diagnostics; +use diagnostics::RetagCause; pub type AllocState = Stacks; @@ -807,7 +809,34 @@ trait EvalContextPrivExt<'mir: 'ecx, 'tcx: 'mir, 'ecx>: crate::MiriInterpCxExt<' impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {} pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { - fn sb_retag( + fn sb_retag_ptr_value( + &mut self, + kind: RetagKind, + val: &ImmTy<'tcx, Provenance>, + ) -> InterpResult<'tcx, ImmTy<'tcx, Provenance>> { + let this = self.eval_context_mut(); + let ref_kind = match val.layout.ty.kind() { + ty::Ref(_, _, mutbl) => { + match mutbl { + Mutability::Mut => + RefKind::Unique { two_phase: kind == RetagKind::TwoPhase }, + Mutability::Not => RefKind::Shared, + } + } + ty::RawPtr(tym) => { + RefKind::Raw { mutable: tym.mutbl == Mutability::Mut } + } + _ => unreachable!(), + }; + let retag_cause = match kind { + RetagKind::TwoPhase { .. } => RetagCause::TwoPhase, + RetagKind::FnEntry => unreachable!(), + RetagKind::Raw | RetagKind::Default => RetagCause::Normal, + }; + this.sb_retag_reference(&val, ref_kind, retag_cause, None) + } + + fn sb_retag_place_contents( &mut self, kind: RetagKind, place: &PlaceTy<'tcx, Provenance>, @@ -815,9 +844,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { let this = self.eval_context_mut(); let retag_fields = this.machine.borrow_tracker.as_mut().unwrap().get_mut().retag_fields; let retag_cause = match kind { - RetagKind::TwoPhase { .. } => RetagCause::TwoPhase, + RetagKind::Raw | RetagKind::TwoPhase { .. } => unreachable!(), RetagKind::FnEntry => RetagCause::FnEntry, - RetagKind::Raw | RetagKind::Default => RetagCause::Normal, + RetagKind::Default => RetagCause::Normal, }; let mut visitor = RetagVisitor { ecx: this, kind, retag_cause, retag_fields }; return visitor.visit_value(place); @@ -831,7 +860,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { } impl<'ecx, 'mir, 'tcx> RetagVisitor<'ecx, 'mir, 'tcx> { #[inline(always)] // yes this helps in our benchmarks - fn retag_place( + fn retag_ptr_inplace( &mut self, place: &PlaceTy<'tcx, Provenance>, ref_kind: RefKind, @@ -856,7 +885,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { fn visit_box(&mut self, place: &PlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> { // Boxes get a weak protectors, since they may be deallocated. - self.retag_place( + self.retag_ptr_inplace( place, RefKind::Box, self.retag_cause, @@ -879,10 +908,10 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { ty::Ref(_, _, mutbl) => { let ref_kind = match mutbl { Mutability::Mut => - RefKind::Unique { two_phase: self.kind == RetagKind::TwoPhase }, + RefKind::Unique { two_phase: false }, Mutability::Not => RefKind::Shared, }; - self.retag_place( + self.retag_ptr_inplace( place, ref_kind, self.retag_cause, @@ -891,21 +920,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { .then_some(ProtectorKind::StrongProtector), )?; } - ty::RawPtr(tym) => { - // We definitely do *not* want to recurse into raw pointers -- wide raw - // pointers have fields, and for dyn Trait pointees those can have reference - // type! - if self.kind == RetagKind::Raw { - // Raw pointers need to be enabled. - self.retag_place( - place, - RefKind::Raw { mutable: tym.mutbl == Mutability::Mut }, - self.retag_cause, - /*protector*/ None, - )?; - } + ty::RawPtr(..) => { + // We do *not* want to recurse into raw pointers -- wide raw pointers have + // fields, and for dyn Trait pointees those can have reference type! } - _ if place.layout.ty.ty_adt_def().is_some_and(|adt| adt.is_box()) => { + ty::Adt(adt, _) if adt.is_box() => { // Recurse for boxes, they require some tricky handling and will end up in `visit_box` above. // (Yes this means we technically also recursively retag the allocator itself // even if field retagging is not enabled. *shrug*) diff --git a/src/tools/miri/src/machine.rs b/src/tools/miri/src/machine.rs index c110229c985..e5b1eb2e487 100644 --- a/src/tools/miri/src/machine.rs +++ b/src/tools/miri/src/machine.rs @@ -967,8 +967,9 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> { ptr: Pointer<Self::Provenance>, ) -> InterpResult<'tcx> { match ptr.provenance { - Provenance::Concrete { alloc_id, tag } => - intptrcast::GlobalStateInner::expose_ptr(ecx, alloc_id, tag), + Provenance::Concrete { alloc_id, tag } => { + intptrcast::GlobalStateInner::expose_ptr(ecx, alloc_id, tag) + } Provenance::Wildcard => { // No need to do anything for wildcard pointers as // their provenances have already been previously exposed. @@ -1055,13 +1056,26 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> { } #[inline(always)] - fn retag( + fn retag_ptr_value( + ecx: &mut InterpCx<'mir, 'tcx, Self>, + kind: mir::RetagKind, + val: &ImmTy<'tcx, Provenance>, + ) -> InterpResult<'tcx, ImmTy<'tcx, Provenance>> { + if ecx.machine.borrow_tracker.is_some() { + ecx.retag_ptr_value(kind, val) + } else { + Ok(val.clone()) + } + } + + #[inline(always)] + fn retag_place_contents( ecx: &mut InterpCx<'mir, 'tcx, Self>, kind: mir::RetagKind, place: &PlaceTy<'tcx, Provenance>, ) -> InterpResult<'tcx> { if ecx.machine.borrow_tracker.is_some() { - ecx.retag(kind, place)?; + ecx.retag_place_contents(kind, place)?; } Ok(()) } |