From cc57656969554bd0dcbf95641bebadc076fac61f Mon Sep 17 00:00:00 2001 From: ouz-a Date: Sat, 9 Apr 2022 20:38:06 +0300 Subject: [PATCH 1/2] support multiple derefs --- .../src/deref_separator.rs | 39 ++++--- .../derefer_test_multiple.main.Derefer.diff | 100 ++++++++++++++++++ src/test/mir-opt/derefer_test_multiple.rs | 9 ++ 3 files changed, 135 insertions(+), 13 deletions(-) create mode 100644 src/test/mir-opt/derefer_test_multiple.main.Derefer.diff create mode 100644 src/test/mir-opt/derefer_test_multiple.rs diff --git a/compiler/rustc_mir_transform/src/deref_separator.rs b/compiler/rustc_mir_transform/src/deref_separator.rs index 79aac16355061..d8660d4f2fd86 100644 --- a/compiler/rustc_mir_transform/src/deref_separator.rs +++ b/compiler/rustc_mir_transform/src/deref_separator.rs @@ -11,6 +11,8 @@ pub fn deref_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { for (i, stmt) in data.statements.iter_mut().enumerate() { match stmt.kind { StatementKind::Assign(box (og_place, Rvalue::Ref(region, borrow_knd, place))) => { + let mut place_local = place.local; + let mut last_len = 0; for (idx, (p_ref, p_elem)) in place.iter_projections().enumerate() { if p_elem == ProjectionElem::Deref && !p_ref.projection.is_empty() { // The type that we are derefing. @@ -23,14 +25,30 @@ pub fn deref_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { patch.add_statement(loc, StatementKind::StorageLive(temp)); // We are adding current p_ref's projections to our - // temp value. - let deref_place = - Place::from(p_ref.local).project_deeper(p_ref.projection, tcx); - patch.add_assign( - loc, - Place::from(temp), - Rvalue::Use(Operand::Move(deref_place)), - ); + // temp value, excluding projections we already covered. + if idx == 1 { + let deref_place = Place::from(place_local) + .project_deeper(&p_ref.projection[last_len..], tcx); + patch.add_assign( + loc, + Place::from(temp), + Rvalue::Use(Operand::Move(deref_place)), + ); + + place_local = temp; + last_len = p_ref.projection.len(); + } else { + let deref_place = Place::from(place_local) + .project_deeper(&p_ref.projection[last_len..], tcx); + patch.add_assign( + loc, + Place::from(temp), + Rvalue::Use(Operand::Move(deref_place)), + ); + + place_local = temp; + last_len = p_ref.projection.len(); + } // We are creating a place by using our temp value's location // and copying derefed values which we need to create new statement. @@ -50,11 +68,6 @@ pub fn deref_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { // Since our job with the temp is done it should be gone let loc = Location { block: block, statement_index: i + 1 }; patch.add_statement(loc, StatementKind::StorageDead(temp)); - - // As all projections are off the base projection, if there are - // multiple derefs in the middle of projection, it might cause - // unsoundness, to not let that happen we break the loop. - break; } } } diff --git a/src/test/mir-opt/derefer_test_multiple.main.Derefer.diff b/src/test/mir-opt/derefer_test_multiple.main.Derefer.diff new file mode 100644 index 0000000000000..d465724326e46 --- /dev/null +++ b/src/test/mir-opt/derefer_test_multiple.main.Derefer.diff @@ -0,0 +1,100 @@ +- // MIR for `main` before Derefer ++ // MIR for `main` after Derefer + + fn main() -> () { + let mut _0: (); // return place in scope 0 at $DIR/derefer_test_multiple.rs:2:12: 2:12 + let mut _1: (i32, i32); // in scope 0 at $DIR/derefer_test_multiple.rs:3:9: 3:14 + let mut _3: &mut (i32, i32); // in scope 0 at $DIR/derefer_test_multiple.rs:4:22: 4:28 + let mut _5: &mut (i32, &mut (i32, i32)); // in scope 0 at $DIR/derefer_test_multiple.rs:5:22: 5:28 + let mut _7: &mut (i32, &mut (i32, &mut (i32, i32))); // in scope 0 at $DIR/derefer_test_multiple.rs:6:22: 6:28 ++ let mut _10: &mut (i32, &mut (i32, &mut (i32, i32))); // in scope 0 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ let mut _11: &mut (i32, &mut (i32, i32)); // in scope 0 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ let mut _12: &mut (i32, i32); // in scope 0 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ let mut _13: &mut (i32, &mut (i32, &mut (i32, i32))); // in scope 0 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ let mut _14: &mut (i32, &mut (i32, i32)); // in scope 0 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ let mut _15: &mut (i32, i32); // in scope 0 at $DIR/derefer_test_multiple.rs:8:13: 8:30 + scope 1 { + debug a => _1; // in scope 1 at $DIR/derefer_test_multiple.rs:3:9: 3:14 + let mut _2: (i32, &mut (i32, i32)); // in scope 1 at $DIR/derefer_test_multiple.rs:4:9: 4:14 + scope 2 { + debug b => _2; // in scope 2 at $DIR/derefer_test_multiple.rs:4:9: 4:14 + let mut _4: (i32, &mut (i32, &mut (i32, i32))); // in scope 2 at $DIR/derefer_test_multiple.rs:5:9: 5:14 + scope 3 { + debug c => _4; // in scope 3 at $DIR/derefer_test_multiple.rs:5:9: 5:14 + let mut _6: (i32, &mut (i32, &mut (i32, &mut (i32, i32)))); // in scope 3 at $DIR/derefer_test_multiple.rs:6:9: 6:14 + scope 4 { + debug d => _6; // in scope 4 at $DIR/derefer_test_multiple.rs:6:9: 6:14 + let _8: &mut i32; // in scope 4 at $DIR/derefer_test_multiple.rs:7:9: 7:10 + scope 5 { + debug x => _8; // in scope 5 at $DIR/derefer_test_multiple.rs:7:9: 7:10 + let _9: &mut i32; // in scope 5 at $DIR/derefer_test_multiple.rs:8:9: 8:10 + scope 6 { + debug y => _9; // in scope 6 at $DIR/derefer_test_multiple.rs:8:9: 8:10 + } + } + } + } + } + } + + bb0: { + StorageLive(_1); // scope 0 at $DIR/derefer_test_multiple.rs:3:9: 3:14 + (_1.0: i32) = const 42_i32; // scope 0 at $DIR/derefer_test_multiple.rs:3:17: 3:25 + (_1.1: i32) = const 43_i32; // scope 0 at $DIR/derefer_test_multiple.rs:3:17: 3:25 + StorageLive(_2); // scope 1 at $DIR/derefer_test_multiple.rs:4:9: 4:14 + StorageLive(_3); // scope 1 at $DIR/derefer_test_multiple.rs:4:22: 4:28 + _3 = &mut _1; // scope 1 at $DIR/derefer_test_multiple.rs:4:22: 4:28 + (_2.0: i32) = const 99_i32; // scope 1 at $DIR/derefer_test_multiple.rs:4:17: 4:29 + (_2.1: &mut (i32, i32)) = move _3; // scope 1 at $DIR/derefer_test_multiple.rs:4:17: 4:29 + StorageDead(_3); // scope 1 at $DIR/derefer_test_multiple.rs:4:28: 4:29 + StorageLive(_4); // scope 2 at $DIR/derefer_test_multiple.rs:5:9: 5:14 + StorageLive(_5); // scope 2 at $DIR/derefer_test_multiple.rs:5:22: 5:28 + _5 = &mut _2; // scope 2 at $DIR/derefer_test_multiple.rs:5:22: 5:28 + (_4.0: i32) = const 11_i32; // scope 2 at $DIR/derefer_test_multiple.rs:5:17: 5:29 + (_4.1: &mut (i32, &mut (i32, i32))) = move _5; // scope 2 at $DIR/derefer_test_multiple.rs:5:17: 5:29 + StorageDead(_5); // scope 2 at $DIR/derefer_test_multiple.rs:5:28: 5:29 + StorageLive(_6); // scope 3 at $DIR/derefer_test_multiple.rs:6:9: 6:14 + StorageLive(_7); // scope 3 at $DIR/derefer_test_multiple.rs:6:22: 6:28 + _7 = &mut _4; // scope 3 at $DIR/derefer_test_multiple.rs:6:22: 6:28 + (_6.0: i32) = const 13_i32; // scope 3 at $DIR/derefer_test_multiple.rs:6:17: 6:29 + (_6.1: &mut (i32, &mut (i32, &mut (i32, i32)))) = move _7; // scope 3 at $DIR/derefer_test_multiple.rs:6:17: 6:29 + StorageDead(_7); // scope 3 at $DIR/derefer_test_multiple.rs:6:28: 6:29 + StorageLive(_8); // scope 4 at $DIR/derefer_test_multiple.rs:7:9: 7:10 +- _8 = &mut ((*((*((*(_6.1: &mut (i32, &mut (i32, &mut (i32, i32))))).1: &mut (i32, &mut (i32, i32)))).1: &mut (i32, i32))).1: i32); // scope 4 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ StorageLive(_10); // scope 4 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ _10 = move (_6.1: &mut (i32, &mut (i32, &mut (i32, i32)))); // scope 4 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ StorageLive(_11); // scope 4 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ _11 = move ((*_10).1: &mut (i32, &mut (i32, i32))); // scope 4 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ StorageLive(_12); // scope 4 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ _12 = move ((*_11).1: &mut (i32, i32)); // scope 4 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ _8 = &mut ((*_12).1: i32); // scope 4 at $DIR/derefer_test_multiple.rs:7:13: 7:30 ++ StorageDead(_10); // scope 5 at $DIR/derefer_test_multiple.rs:8:9: 8:10 ++ StorageDead(_11); // scope 5 at $DIR/derefer_test_multiple.rs:8:9: 8:10 ++ StorageDead(_12); // scope 5 at $DIR/derefer_test_multiple.rs:8:9: 8:10 + StorageLive(_9); // scope 5 at $DIR/derefer_test_multiple.rs:8:9: 8:10 +- _9 = &mut ((*((*((*(_6.1: &mut (i32, &mut (i32, &mut (i32, i32))))).1: &mut (i32, &mut (i32, i32)))).1: &mut (i32, i32))).1: i32); // scope 5 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ StorageLive(_13); // scope 5 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ _13 = move (_6.1: &mut (i32, &mut (i32, &mut (i32, i32)))); // scope 5 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ StorageLive(_14); // scope 5 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ _14 = move ((*_13).1: &mut (i32, &mut (i32, i32))); // scope 5 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ StorageLive(_15); // scope 5 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ _15 = move ((*_14).1: &mut (i32, i32)); // scope 5 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ _9 = &mut ((*_15).1: i32); // scope 5 at $DIR/derefer_test_multiple.rs:8:13: 8:30 ++ StorageDead(_13); // scope 0 at $DIR/derefer_test_multiple.rs:2:12: 9:2 ++ StorageDead(_14); // scope 0 at $DIR/derefer_test_multiple.rs:2:12: 9:2 ++ StorageDead(_15); // scope 0 at $DIR/derefer_test_multiple.rs:2:12: 9:2 + _0 = const (); // scope 0 at $DIR/derefer_test_multiple.rs:2:12: 9:2 + StorageDead(_9); // scope 5 at $DIR/derefer_test_multiple.rs:9:1: 9:2 + StorageDead(_8); // scope 4 at $DIR/derefer_test_multiple.rs:9:1: 9:2 + StorageDead(_6); // scope 3 at $DIR/derefer_test_multiple.rs:9:1: 9:2 + StorageDead(_4); // scope 2 at $DIR/derefer_test_multiple.rs:9:1: 9:2 + StorageDead(_2); // scope 1 at $DIR/derefer_test_multiple.rs:9:1: 9:2 + StorageDead(_1); // scope 0 at $DIR/derefer_test_multiple.rs:9:1: 9:2 + return; // scope 0 at $DIR/derefer_test_multiple.rs:9:2: 9:2 ++ } ++ ++ bb1 (cleanup): { ++ resume; // scope 0 at $DIR/derefer_test_multiple.rs:2:1: 9:2 + } + } + diff --git a/src/test/mir-opt/derefer_test_multiple.rs b/src/test/mir-opt/derefer_test_multiple.rs new file mode 100644 index 0000000000000..a27363447fee5 --- /dev/null +++ b/src/test/mir-opt/derefer_test_multiple.rs @@ -0,0 +1,9 @@ +// EMIT_MIR derefer_test_multiple.main.Derefer.diff +fn main () { + let mut a = (42, 43); + let mut b = (99, &mut a); + let mut c = (11, &mut b); + let mut d = (13, &mut c); + let x = &mut (*d.1).1.1.1; + let y = &mut (*d.1).1.1.1; +} From 80afd9db2e3871387ecab9c2bdeffc0f970d32d3 Mon Sep 17 00:00:00 2001 From: ouz-a Date: Sat, 9 Apr 2022 22:23:49 +0300 Subject: [PATCH 2/2] remove the if block --- .../src/deref_separator.rs | 31 ++++++------------- 1 file changed, 9 insertions(+), 22 deletions(-) diff --git a/compiler/rustc_mir_transform/src/deref_separator.rs b/compiler/rustc_mir_transform/src/deref_separator.rs index d8660d4f2fd86..24b626ad96658 100644 --- a/compiler/rustc_mir_transform/src/deref_separator.rs +++ b/compiler/rustc_mir_transform/src/deref_separator.rs @@ -26,29 +26,16 @@ pub fn deref_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { // We are adding current p_ref's projections to our // temp value, excluding projections we already covered. - if idx == 1 { - let deref_place = Place::from(place_local) - .project_deeper(&p_ref.projection[last_len..], tcx); - patch.add_assign( - loc, - Place::from(temp), - Rvalue::Use(Operand::Move(deref_place)), - ); + let deref_place = Place::from(place_local) + .project_deeper(&p_ref.projection[last_len..], tcx); + patch.add_assign( + loc, + Place::from(temp), + Rvalue::Use(Operand::Move(deref_place)), + ); - place_local = temp; - last_len = p_ref.projection.len(); - } else { - let deref_place = Place::from(place_local) - .project_deeper(&p_ref.projection[last_len..], tcx); - patch.add_assign( - loc, - Place::from(temp), - Rvalue::Use(Operand::Move(deref_place)), - ); - - place_local = temp; - last_len = p_ref.projection.len(); - } + place_local = temp; + last_len = p_ref.projection.len(); // We are creating a place by using our temp value's location // and copying derefed values which we need to create new statement.