Auto merge of #133474 - RalfJung:gvn-miscompile, r=compiler-errors

Do not unify dereferences of shared borrows in GVN Repost of #132461, the last commit applies my suggestions. Fixes #130853
rust-lang · Nov 27, 2024 · 6b6a867 · 6b6a867
2 parents c322cd5 + 906f66f
commit 6b6a867
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Showing 33 changed files with 614 additions and 482 deletions.
diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs
@@ -638,7 +638,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
         let proj = match proj {
             ProjectionElem::Deref => {
                 let ty = place.ty(self.local_decls, self.tcx).ty;
-                if let Some(Mutability::Not) = ty.ref_mutability()
+                // unsound: https://github.com/rust-lang/rust/issues/130853
+                if self.tcx.sess.opts.unstable_opts.unsound_mir_opts
+                    && let Some(Mutability::Not) = ty.ref_mutability()
                     && let Some(pointee_ty) = ty.builtin_deref(true)
                     && pointee_ty.is_freeze(self.tcx, self.typing_env())
                 {

diff --git a/tests/coverage/closure.cov-map b/tests/coverage/closure.cov-map
@@ -140,17 +140,19 @@ Number of file 0 mappings: 6
 - Code(Counter(0)) at (prev + 2, 9) to (start + 0, 10)
 Highest counter ID seen: c1
 
-Function name: closure::main::{closure#18} (unused)
-Raw bytes (24): 0x[01, 01, 00, 04, 00, 19, 0d, 02, 1c, 00, 02, 1d, 02, 12, 00, 02, 11, 00, 12, 00, 01, 11, 01, 0e]
+Function name: closure::main::{closure#18}
+Raw bytes (26): 0x[01, 01, 01, 01, 05, 04, 01, 19, 0d, 02, 1c, 05, 02, 1d, 02, 12, 02, 02, 11, 00, 12, 01, 01, 11, 01, 0e]
 Number of files: 1
 - file 0 => global file 1
-Number of expressions: 0
+Number of expressions: 1
+- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
 Number of file 0 mappings: 4
-- Code(Zero) at (prev + 25, 13) to (start + 2, 28)
-- Code(Zero) at (prev + 2, 29) to (start + 2, 18)
-- Code(Zero) at (prev + 2, 17) to (start + 0, 18)
-- Code(Zero) at (prev + 1, 17) to (start + 1, 14)
-Highest counter ID seen: (none)
+- Code(Counter(0)) at (prev + 25, 13) to (start + 2, 28)
+- Code(Counter(1)) at (prev + 2, 29) to (start + 2, 18)
+- Code(Expression(0, Sub)) at (prev + 2, 17) to (start + 0, 18)
+    = (c0 - c1)
+- Code(Counter(0)) at (prev + 1, 17) to (start + 1, 14)
+Highest counter ID seen: c1
 
 Function name: closure::main::{closure#19}
 Raw bytes (26): 0x[01, 01, 01, 01, 05, 04, 01, 43, 0d, 02, 1c, 05, 02, 1d, 02, 12, 02, 02, 11, 00, 12, 01, 01, 11, 01, 0e]

diff --git a/tests/coverage/issue-84561.cov-map b/tests/coverage/issue-84561.cov-map
diff --git a/tests/mir-opt/const_prop/read_immutable_static.main.GVN.diff b/tests/mir-opt/const_prop/read_immutable_static.main.GVN.diff
@@ -14,23 +14,19 @@
 
       bb0: {
           StorageLive(_1);
--         StorageLive(_2);
+          StorageLive(_2);
 -         StorageLive(_3);
-+         nop;
 +         nop;
           _3 = const {ALLOC0: &u8};
--         _2 = copy (*_3);
-+         _2 = const 2_u8;
+          _2 = copy (*_3);
           StorageLive(_4);
           StorageLive(_5);
           _5 = const {ALLOC0: &u8};
 -         _4 = copy (*_5);
--         _1 = Add(move _2, move _4);
-+         _4 = const 2_u8;
-+         _1 = const 4_u8;
++         _4 = copy (*_3);
+          _1 = Add(move _2, move _4);
           StorageDead(_4);
--         StorageDead(_2);
-+         nop;
+          StorageDead(_2);
           StorageDead(_5);
 -         StorageDead(_3);
 +         nop;

diff --git a/tests/mir-opt/const_prop/read_immutable_static.rs b/tests/mir-opt/const_prop/read_immutable_static.rs
@@ -6,6 +6,7 @@ static FOO: u8 = 2;
 fn main() {
     // CHECK-LABEL: fn main(
     // CHECK: debug x => [[x:_.*]];
-    // CHECK: [[x]] = const 4_u8;
+    // Disabled due to <https://github.com/rust-lang/rust/issues/130853>
+    // COM: CHECK: [[x]] = const 4_u8;
     let x = FOO + FOO;
 }
diff --git a/tests/mir-opt/const_prop/ref_deref.main.GVN.diff b/tests/mir-opt/const_prop/ref_deref.main.GVN.diff
@@ -16,8 +16,7 @@
           StorageLive(_2);
           _4 = const main::promoted[0];
           _2 = &(*_4);
--         _1 = copy (*_2);
-+         _1 = const 4_i32;
+          _1 = copy (*_2);
           StorageDead(_2);
           _0 = const ();
           StorageDead(_1);

diff --git a/tests/mir-opt/const_prop/ref_deref_project.main.GVN.diff b/tests/mir-opt/const_prop/ref_deref_project.main.GVN.diff
@@ -16,8 +16,7 @@
           StorageLive(_2);
           _4 = const main::promoted[0];
           _2 = &((*_4).1: i32);
--         _1 = copy (*_2);
-+         _1 = const 5_i32;
+          _1 = copy (*_2);
           StorageDead(_2);
           _0 = const ();
           StorageDead(_1);

diff --git a/tests/mir-opt/const_prop/ref_deref_project.rs b/tests/mir-opt/const_prop/ref_deref_project.rs
@@ -5,6 +5,7 @@
 fn main() {
     // CHECK-LABEL: fn main(
     // CHECK: debug a => [[a:_.*]];
-    // CHECK: [[a]] = const 5_i32;
+    // Disabled due to <https://github.com/rust-lang/rust/issues/130853>
+    // COM: CHECK: [[a]] = const 5_i32;
     let a = *(&(4, 5).1);
 }
diff --git a/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-abort.diff b/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-abort.diff
@@ -30,17 +30,16 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
--         _7 = Len((*_2));
+          _7 = Len((*_2));
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _7 = const 3_usize;
-+         _8 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind unreachable];
++         _8 = Lt(const 1_usize, copy _7);
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind unreachable];
       }
 
       bb1: {
 -         _1 = copy (*_2)[_6];
-+         _1 = const 2_u32;
++         _1 = copy (*_2)[1 of 2];
           StorageDead(_6);
           StorageDead(_4);
           StorageDead(_2);

diff --git a/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-unwind.diff b/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-unwind.diff
@@ -30,17 +30,16 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
--         _7 = Len((*_2));
+          _7 = Len((*_2));
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _7 = const 3_usize;
-+         _8 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind continue];
++         _8 = Lt(const 1_usize, copy _7);
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind continue];
       }
 
       bb1: {
 -         _1 = copy (*_2)[_6];
-+         _1 = const 2_u32;
++         _1 = copy (*_2)[1 of 2];
           StorageDead(_6);
           StorageDead(_4);
           StorageDead(_2);

diff --git a/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-abort.diff b/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-abort.diff
@@ -30,17 +30,16 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
--         _7 = Len((*_2));
+          _7 = Len((*_2));
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _7 = const 3_usize;
-+         _8 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind unreachable];
++         _8 = Lt(const 1_usize, copy _7);
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind unreachable];
       }
 
       bb1: {
 -         _1 = copy (*_2)[_6];
-+         _1 = const 2_u32;
++         _1 = copy (*_2)[1 of 2];
           StorageDead(_6);
           StorageDead(_4);
           StorageDead(_2);

diff --git a/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-unwind.diff b/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-unwind.diff
@@ -30,17 +30,16 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
--         _7 = Len((*_2));
+          _7 = Len((*_2));
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _7 = const 3_usize;
-+         _8 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind continue];
++         _8 = Lt(const 1_usize, copy _7);
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind continue];
       }
 
       bb1: {
 -         _1 = copy (*_2)[_6];
-+         _1 = const 2_u32;
++         _1 = copy (*_2)[1 of 2];
           StorageDead(_6);
           StorageDead(_4);
           StorageDead(_2);

diff --git a/tests/mir-opt/const_prop/slice_len.rs b/tests/mir-opt/const_prop/slice_len.rs
@@ -8,7 +8,8 @@ fn main() {
     // CHECK-LABEL: fn main(
     // CHECK: debug a => [[a:_.*]];
     // CHECK: [[slice:_.*]] = copy {{.*}} as &[u32] (PointerCoercion(Unsize, AsCast));
-    // CHECK: assert(const true,
-    // CHECK: [[a]] = const 2_u32;
+    // Disabled due to <https://github.com/rust-lang/rust/issues/130853>
+    // COM: CHECK: assert(const true,
+    // COM: CHECK: [[a]] = const 2_u32;
     let a = (&[1u32, 2, 3] as &[u32])[1];
 }
diff --git a/tests/mir-opt/gvn.borrowed.GVN.panic-abort.diff b/tests/mir-opt/gvn.borrowed.GVN.panic-abort.diff
@@ -18,8 +18,7 @@
       }
 
       bb2: {
--         _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind unreachable];
-+         _0 = opaque::<T>(copy _1) -> [return: bb3, unwind unreachable];
+          _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind unreachable];
       }
 
       bb3: {

diff --git a/tests/mir-opt/gvn.borrowed.GVN.panic-unwind.diff b/tests/mir-opt/gvn.borrowed.GVN.panic-unwind.diff
@@ -18,8 +18,7 @@
       }
 
       bb2: {
--         _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind continue];
-+         _0 = opaque::<T>(copy _1) -> [return: bb3, unwind continue];
+          _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind continue];
       }
 
       bb3: {

diff --git a/tests/mir-opt/gvn.dereferences.GVN.panic-abort.diff b/tests/mir-opt/gvn.dereferences.GVN.panic-abort.diff
@@ -107,23 +107,18 @@
           StorageLive(_18);
           _18 = &(*_1);
           StorageLive(_19);
--         StorageLive(_20);
-+         nop;
+          StorageLive(_20);
           _20 = copy (*_18);
--         _19 = opaque::<u32>(move _20) -> [return: bb7, unwind unreachable];
-+         _19 = opaque::<u32>(copy _20) -> [return: bb7, unwind unreachable];
+          _19 = opaque::<u32>(move _20) -> [return: bb7, unwind unreachable];
       }
 
       bb7: {
--         StorageDead(_20);
-+         nop;
+          StorageDead(_20);
           StorageDead(_19);
           StorageLive(_21);
           StorageLive(_22);
--         _22 = copy (*_18);
--         _21 = opaque::<u32>(move _22) -> [return: bb8, unwind unreachable];
-+         _22 = copy _20;
-+         _21 = opaque::<u32>(copy _20) -> [return: bb8, unwind unreachable];
+          _22 = copy (*_18);
+          _21 = opaque::<u32>(move _22) -> [return: bb8, unwind unreachable];
       }
 
       bb8: {
@@ -157,23 +152,18 @@
           StorageDead(_28);
           StorageDead(_27);
           StorageLive(_29);
--         StorageLive(_30);
-+         nop;
+          StorageLive(_30);
           _30 = copy ((*_3).0: u32);
--         _29 = opaque::<u32>(move _30) -> [return: bb12, unwind unreachable];
-+         _29 = opaque::<u32>(copy _30) -> [return: bb12, unwind unreachable];
+          _29 = opaque::<u32>(move _30) -> [return: bb12, unwind unreachable];
       }
 
       bb12: {
--         StorageDead(_30);
-+         nop;
+          StorageDead(_30);
           StorageDead(_29);
           StorageLive(_31);
           StorageLive(_32);
--         _32 = copy ((*_3).0: u32);
--         _31 = opaque::<u32>(move _32) -> [return: bb13, unwind unreachable];
-+         _32 = copy _30;
-+         _31 = opaque::<u32>(copy _30) -> [return: bb13, unwind unreachable];
+          _32 = copy ((*_3).0: u32);
+          _31 = opaque::<u32>(move _32) -> [return: bb13, unwind unreachable];
       }
 
       bb13: {

diff --git a/tests/mir-opt/gvn.dereferences.GVN.panic-unwind.diff b/tests/mir-opt/gvn.dereferences.GVN.panic-unwind.diff
@@ -107,23 +107,18 @@
           StorageLive(_18);
           _18 = &(*_1);
           StorageLive(_19);
--         StorageLive(_20);
-+         nop;
+          StorageLive(_20);
           _20 = copy (*_18);
--         _19 = opaque::<u32>(move _20) -> [return: bb7, unwind continue];
-+         _19 = opaque::<u32>(copy _20) -> [return: bb7, unwind continue];
+          _19 = opaque::<u32>(move _20) -> [return: bb7, unwind continue];
       }
 
       bb7: {
--         StorageDead(_20);
-+         nop;
+          StorageDead(_20);
           StorageDead(_19);
           StorageLive(_21);
           StorageLive(_22);
--         _22 = copy (*_18);
--         _21 = opaque::<u32>(move _22) -> [return: bb8, unwind continue];
-+         _22 = copy _20;
-+         _21 = opaque::<u32>(copy _20) -> [return: bb8, unwind continue];
+          _22 = copy (*_18);
+          _21 = opaque::<u32>(move _22) -> [return: bb8, unwind continue];
       }
 
       bb8: {
@@ -157,23 +152,18 @@
           StorageDead(_28);
           StorageDead(_27);
           StorageLive(_29);
--         StorageLive(_30);
-+         nop;
+          StorageLive(_30);
           _30 = copy ((*_3).0: u32);
--         _29 = opaque::<u32>(move _30) -> [return: bb12, unwind continue];
-+         _29 = opaque::<u32>(copy _30) -> [return: bb12, unwind continue];
+          _29 = opaque::<u32>(move _30) -> [return: bb12, unwind continue];
       }
 
       bb12: {
--         StorageDead(_30);
-+         nop;
+          StorageDead(_30);
           StorageDead(_29);
           StorageLive(_31);
           StorageLive(_32);
--         _32 = copy ((*_3).0: u32);
--         _31 = opaque::<u32>(move _32) -> [return: bb13, unwind continue];
-+         _32 = copy _30;
-+         _31 = opaque::<u32>(copy _30) -> [return: bb13, unwind continue];
+          _32 = copy ((*_3).0: u32);
+          _31 = opaque::<u32>(move _32) -> [return: bb13, unwind continue];
       }
 
       bb13: {

diff --git a/tests/mir-opt/gvn.fn_pointers.GVN.panic-abort.diff b/tests/mir-opt/gvn.fn_pointers.GVN.panic-abort.diff
@@ -8,18 +8,18 @@
       let mut _3: fn(u8) -> u8;
       let _5: ();
       let mut _6: fn(u8) -> u8;
-      let mut _9: {closure@$DIR/gvn.rs:614:19: 614:21};
+      let mut _9: {closure@$DIR/gvn.rs:615:19: 615:21};
       let _10: ();
       let mut _11: fn();
-      let mut _13: {closure@$DIR/gvn.rs:614:19: 614:21};
+      let mut _13: {closure@$DIR/gvn.rs:615:19: 615:21};
       let _14: ();
       let mut _15: fn();
       scope 1 {
           debug f => _1;
           let _4: fn(u8) -> u8;
           scope 2 {
               debug g => _4;
-              let _7: {closure@$DIR/gvn.rs:614:19: 614:21};
+              let _7: {closure@$DIR/gvn.rs:615:19: 615:21};
               scope 3 {
                   debug closure => _7;
                   let _8: fn();
@@ -62,16 +62,16 @@
           StorageDead(_6);
           StorageDead(_5);
 -         StorageLive(_7);
--         _7 = {closure@$DIR/gvn.rs:614:19: 614:21};
+-         _7 = {closure@$DIR/gvn.rs:615:19: 615:21};
 -         StorageLive(_8);
 +         nop;
-+         _7 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
++         _7 = const ZeroSized: {closure@$DIR/gvn.rs:615:19: 615:21};
 +         nop;
           StorageLive(_9);
 -         _9 = copy _7;
 -         _8 = move _9 as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
-+         _9 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
-+         _8 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
++         _9 = const ZeroSized: {closure@$DIR/gvn.rs:615:19: 615:21};
++         _8 = const ZeroSized: {closure@$DIR/gvn.rs:615:19: 615:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
           StorageDead(_9);
           StorageLive(_10);
           StorageLive(_11);
@@ -88,8 +88,8 @@
           StorageLive(_13);
 -         _13 = copy _7;
 -         _12 = move _13 as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
-+         _13 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
-+         _12 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
++         _13 = const ZeroSized: {closure@$DIR/gvn.rs:615:19: 615:21};
++         _12 = const ZeroSized: {closure@$DIR/gvn.rs:615:19: 615:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
           StorageDead(_13);
           StorageLive(_14);
           StorageLive(_15);
-Original file line number
+Diff line change
@@ Expand Up / @@ -18,8 +18,7 @@ @@
           }
           bb2: {
-    -         _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind unreachable];
-    +         _0 = opaque::<T>(copy _1) -> [return: bb3, unwind unreachable];
+              _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind unreachable];
           }
           bb3: {
@@ Expand Down @@