diff options
| -rw-r--r-- | compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs | 9 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/intrinsic.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/const_eval/machine.rs | 49 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/const_eval/valtrees.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_span/src/symbol.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_typeck/src/check/intrinsic.rs | 7 | ||||
| -rw-r--r-- | library/core/src/intrinsics.rs | 25 | ||||
| -rw-r--r-- | library/core/src/ptr/const_ptr.rs | 55 | ||||
| -rw-r--r-- | library/core/src/ptr/mut_ptr.rs | 49 | ||||
| -rw-r--r-- | src/test/ui/consts/miri_unleashed/slice_eq.rs | 12 | ||||
| -rw-r--r-- | src/test/ui/consts/ptr_comparisons.rs | 24 | ||||
| -rw-r--r-- | src/test/ui/consts/ptr_comparisons.stderr | 14 |
12 files changed, 119 insertions, 138 deletions
diff --git a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs index 0cd9332a58b..2e4ca594f91 100644 --- a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs +++ b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs @@ -816,20 +816,13 @@ fn codegen_regular_intrinsic_call<'tcx>( ret.write_cvalue(fx, val); } - sym::ptr_guaranteed_eq => { + sym::ptr_guaranteed_cmp => { intrinsic_args!(fx, args => (a, b); intrinsic); let val = crate::num::codegen_ptr_binop(fx, BinOp::Eq, a, b); ret.write_cvalue(fx, val); } - sym::ptr_guaranteed_ne => { - intrinsic_args!(fx, args => (a, b); intrinsic); - - let val = crate::num::codegen_ptr_binop(fx, BinOp::Ne, a, b); - ret.write_cvalue(fx, val); - } - sym::caller_location => { intrinsic_args!(fx, args => (); intrinsic); diff --git a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs index 6393dd9d634..215edbe02c0 100644 --- a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs +++ b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs @@ -551,14 +551,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { return; } - sym::ptr_guaranteed_eq | sym::ptr_guaranteed_ne => { + sym::ptr_guaranteed_cmp => { let a = args[0].immediate(); let b = args[1].immediate(); - if name == sym::ptr_guaranteed_eq { - bx.icmp(IntPredicate::IntEQ, a, b) - } else { - bx.icmp(IntPredicate::IntNE, a, b) - } + bx.icmp(IntPredicate::IntEQ, a, b) } sym::ptr_offset_from | sym::ptr_offset_from_unsigned => { diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs index 6e5c840bdfd..e5acacd9188 100644 --- a/compiler/rustc_const_eval/src/const_eval/machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/machine.rs @@ -191,34 +191,35 @@ impl interpret::MayLeak for ! { } impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> { - fn guaranteed_eq(&mut self, a: Scalar, b: Scalar) -> InterpResult<'tcx, bool> { + /// See documentation on the `ptr_guaranteed_cmp` intrinsic. + fn guaranteed_cmp(&mut self, a: Scalar, b: Scalar) -> InterpResult<'tcx, u8> { Ok(match (a, b) { // Comparisons between integers are always known. - (Scalar::Int { .. }, Scalar::Int { .. }) => a == b, - // Equality with integers can never be known for sure. - (Scalar::Int { .. }, Scalar::Ptr(..)) | (Scalar::Ptr(..), Scalar::Int { .. }) => false, - // FIXME: return `true` for when both sides are the same pointer, *except* that - // some things (like functions and vtables) do not have stable addresses - // so we need to be careful around them (see e.g. #73722). - (Scalar::Ptr(..), Scalar::Ptr(..)) => false, - }) - } - - fn guaranteed_ne(&mut self, a: Scalar, b: Scalar) -> InterpResult<'tcx, bool> { - Ok(match (a, b) { - // Comparisons between integers are always known. - (Scalar::Int(_), Scalar::Int(_)) => a != b, + (Scalar::Int { .. }, Scalar::Int { .. }) => { + if a == b { + 1 + } else { + 0 + } + } // Comparisons of abstract pointers with null pointers are known if the pointer // is in bounds, because if they are in bounds, the pointer can't be null. // Inequality with integers other than null can never be known for sure. (Scalar::Int(int), ptr @ Scalar::Ptr(..)) - | (ptr @ Scalar::Ptr(..), Scalar::Int(int)) => { - int.is_null() && !self.scalar_may_be_null(ptr)? + | (ptr @ Scalar::Ptr(..), Scalar::Int(int)) + if int.is_null() && !self.scalar_may_be_null(ptr)? => + { + 0 } - // FIXME: return `true` for at least some comparisons where we can reliably + // Equality with integers can never be known for sure. + (Scalar::Int { .. }, Scalar::Ptr(..)) | (Scalar::Ptr(..), Scalar::Int { .. }) => 2, + // FIXME: return a `1` for when both sides are the same pointer, *except* that + // some things (like functions and vtables) do not have stable addresses + // so we need to be careful around them (see e.g. #73722). + // FIXME: return `0` for at least some comparisons where we can reliably // determine the result of runtime inequality tests at compile-time. // Examples include comparison of addresses in different static items. - (Scalar::Ptr(..), Scalar::Ptr(..)) => false, + (Scalar::Ptr(..), Scalar::Ptr(..)) => 2, }) } } @@ -329,15 +330,11 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir, throw_unsup_format!("intrinsic `{intrinsic_name}` is not supported at compile-time"); }; match intrinsic_name { - sym::ptr_guaranteed_eq | sym::ptr_guaranteed_ne => { + sym::ptr_guaranteed_cmp => { let a = ecx.read_scalar(&args[0])?; let b = ecx.read_scalar(&args[1])?; - let cmp = if intrinsic_name == sym::ptr_guaranteed_eq { - ecx.guaranteed_eq(a, b)? - } else { - ecx.guaranteed_ne(a, b)? - }; - ecx.write_scalar(Scalar::from_bool(cmp), dest)?; + let cmp = ecx.guaranteed_cmp(a, b)?; + ecx.write_scalar(Scalar::from_u8(cmp), dest)?; } sym::const_allocate => { let size = ecx.read_scalar(&args[0])?.to_machine_usize(ecx)?; diff --git a/compiler/rustc_const_eval/src/const_eval/valtrees.rs b/compiler/rustc_const_eval/src/const_eval/valtrees.rs index 8b7c3cf3377..a964fe8465e 100644 --- a/compiler/rustc_const_eval/src/const_eval/valtrees.rs +++ b/compiler/rustc_const_eval/src/const_eval/valtrees.rs @@ -97,7 +97,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>( } // Raw pointers are not allowed in type level constants, as we cannot properly test them for - // equality at compile-time (see `ptr_guaranteed_eq`/`_ne`). + // equality at compile-time (see `ptr_guaranteed_cmp`). // Technically we could allow function pointers (represented as `ty::Instance`), but this is not guaranteed to // agree with runtime equality tests. ty::FnPtr(_) | ty::RawPtr(_) => Err(ValTreeCreationError::NonSupportedType), diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index f2876344c65..9c3d99deae0 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -1117,8 +1117,7 @@ symbols! { profiler_builtins, profiler_runtime, ptr, - ptr_guaranteed_eq, - ptr_guaranteed_ne, + ptr_guaranteed_cmp, ptr_mask, ptr_null, ptr_null_mut, diff --git a/compiler/rustc_typeck/src/check/intrinsic.rs b/compiler/rustc_typeck/src/check/intrinsic.rs index 73dd7122e26..4fa33da50c9 100644 --- a/compiler/rustc_typeck/src/check/intrinsic.rs +++ b/compiler/rustc_typeck/src/check/intrinsic.rs @@ -95,8 +95,7 @@ pub fn intrinsic_operation_unsafety(intrinsic: Symbol) -> hir::Unsafety { | sym::type_id | sym::likely | sym::unlikely - | sym::ptr_guaranteed_eq - | sym::ptr_guaranteed_ne + | sym::ptr_guaranteed_cmp | sym::minnumf32 | sym::minnumf64 | sym::maxnumf32 @@ -302,8 +301,8 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) { (1, vec![param(0), param(0)], tcx.intern_tup(&[param(0), tcx.types.bool])) } - sym::ptr_guaranteed_eq | sym::ptr_guaranteed_ne => { - (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.bool) + sym::ptr_guaranteed_cmp => { + (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.u8) } sym::const_allocate => { diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs index 56f5824efd4..11c75e2c912 100644 --- a/library/core/src/intrinsics.rs +++ b/library/core/src/intrinsics.rs @@ -2013,21 +2013,24 @@ extern "rust-intrinsic" { pub fn ptr_offset_from_unsigned<T>(ptr: *const T, base: *const T) -> usize; /// See documentation of `<*const T>::guaranteed_eq` for details. + /// Returns `2` if the result is unknown. + /// Returns `1` if the pointers are guaranteed equal + /// Returns `0` if the pointers are guaranteed inequal /// /// Note that, unlike most intrinsics, this is safe to call; /// it does not require an `unsafe` block. /// Therefore, implementations must not require the user to uphold /// any safety invariants. #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] + #[cfg(not(bootstrap))] + pub fn ptr_guaranteed_cmp<T>(ptr: *const T, other: *const T) -> u8; + + #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] + #[cfg(bootstrap)] pub fn ptr_guaranteed_eq<T>(ptr: *const T, other: *const T) -> bool; - /// See documentation of `<*const T>::guaranteed_ne` for details. - /// - /// Note that, unlike most intrinsics, this is safe to call; - /// it does not require an `unsafe` block. - /// Therefore, implementations must not require the user to uphold - /// any safety invariants. #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] + #[cfg(bootstrap)] pub fn ptr_guaranteed_ne<T>(ptr: *const T, other: *const T) -> bool; /// Allocates a block of memory at compile time. @@ -2213,6 +2216,16 @@ pub(crate) fn is_nonoverlapping<T>(src: *const T, dst: *const T, count: usize) - diff >= size } +#[cfg(bootstrap)] +pub const fn ptr_guaranteed_cmp(a: *const (), b: *const ()) -> u8 { + match (ptr_guaranteed_eq(a, b), ptr_guaranteed_ne(a, b)) { + (false, false) => 2, + (true, false) => 1, + (false, true) => 0, + (true, true) => unreachable!(), + } +} + /// Copies `count * size_of::<T>()` bytes from `src` to `dst`. The source /// and destination must *not* overlap. /// diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs index 80bff74f3e9..fcdf69a7aaa 100644 --- a/library/core/src/ptr/const_ptr.rs +++ b/library/core/src/ptr/const_ptr.rs @@ -36,7 +36,10 @@ impl<T: ?Sized> *const T { pub const fn is_null(self) -> bool { // Compare via a cast to a thin pointer, so fat pointers are only // considering their "data" part for null-ness. - (self as *const u8).guaranteed_eq(null()) + match (self as *const u8).guaranteed_eq(null()) { + None => false, + Some(res) => res, + } } /// Casts to a pointer of another type. @@ -770,20 +773,16 @@ impl<T: ?Sized> *const T { /// Returns whether two pointers are guaranteed to be equal. /// - /// At runtime this function behaves like `self == other`. + /// At runtime this function behaves like `Some(self == other)`. /// However, in some contexts (e.g., compile-time evaluation), /// it is not always possible to determine equality of two pointers, so this function may - /// spuriously return `false` for pointers that later actually turn out to be equal. - /// But when it returns `true`, the pointers are guaranteed to be equal. - /// - /// This function is the mirror of [`guaranteed_ne`], but not its inverse. There are pointer - /// comparisons for which both functions return `false`. + /// spuriously return `None` for pointers that later actually turn out to have its equality known. + /// But when it returns `Some`, the pointers' equality is guaranteed to be known. /// - /// [`guaranteed_ne`]: #method.guaranteed_ne - /// - /// The return value may change depending on the compiler version and unsafe code must not + /// The return value may change from `Some` to `None` and vice versa depending on the compiler + /// version and unsafe code must not /// rely on the result of this function for soundness. It is suggested to only use this function - /// for performance optimizations where spurious `false` return values by this function do not + /// for performance optimizations where spurious `None` return values by this function do not /// affect the outcome, but just the performance. /// The consequences of using this method to make runtime and compile-time code behave /// differently have not been explored. This method should not be used to introduce such @@ -792,29 +791,28 @@ impl<T: ?Sized> *const T { #[unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[inline] - pub const fn guaranteed_eq(self, other: *const T) -> bool + pub const fn guaranteed_eq(self, other: *const T) -> Option<bool> where T: Sized, { - intrinsics::ptr_guaranteed_eq(self, other) + match intrinsics::ptr_guaranteed_cmp(self as _, other as _) { + 2 => None, + other => Some(other == 1), + } } - /// Returns whether two pointers are guaranteed to be unequal. + /// Returns whether two pointers are guaranteed to be inequal. /// - /// At runtime this function behaves like `self != other`. + /// At runtime this function behaves like `Some(self == other)`. /// However, in some contexts (e.g., compile-time evaluation), - /// it is not always possible to determine the inequality of two pointers, so this function may - /// spuriously return `false` for pointers that later actually turn out to be unequal. - /// But when it returns `true`, the pointers are guaranteed to be unequal. + /// it is not always possible to determine inequality of two pointers, so this function may + /// spuriously return `None` for pointers that later actually turn out to have its inequality known. + /// But when it returns `Some`, the pointers' inequality is guaranteed to be known. /// - /// This function is the mirror of [`guaranteed_eq`], but not its inverse. There are pointer - /// comparisons for which both functions return `false`. - /// - /// [`guaranteed_eq`]: #method.guaranteed_eq - /// - /// The return value may change depending on the compiler version and unsafe code must not + /// The return value may change from `Some` to `None` and vice versa depending on the compiler + /// version and unsafe code must not /// rely on the result of this function for soundness. It is suggested to only use this function - /// for performance optimizations where spurious `false` return values by this function do not + /// for performance optimizations where spurious `None` return values by this function do not /// affect the outcome, but just the performance. /// The consequences of using this method to make runtime and compile-time code behave /// differently have not been explored. This method should not be used to introduce such @@ -823,11 +821,14 @@ impl<T: ?Sized> *const T { #[unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[inline] - pub const fn guaranteed_ne(self, other: *const T) -> bool + pub const fn guaranteed_ne(self, other: *const T) -> Option<bool> where T: Sized, { - intrinsics::ptr_guaranteed_ne(self, other) + match self.guaranteed_eq(other) { + None => None, + Some(eq) => Some(!eq), + } } /// Calculates the offset from a pointer (convenience for `.offset(count as isize)`). diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs index 3e4c3ae0756..460f3df5fee 100644 --- a/library/core/src/ptr/mut_ptr.rs +++ b/library/core/src/ptr/mut_ptr.rs @@ -35,7 +35,10 @@ impl<T: ?Sized> *mut T { pub const fn is_null(self) -> bool { // Compare via a cast to a thin pointer, so fat pointers are only // considering their "data" part for null-ness. - (self as *mut u8).guaranteed_eq(null_mut()) + match (self as *mut u8).guaranteed_eq(null_mut()) { + None => false, + Some(res) => res, + } } /// Casts to a pointer of another type. @@ -697,20 +700,16 @@ impl<T: ?Sized> *mut T { /// Returns whether two pointers are guaranteed to be equal. /// - /// At runtime this function behaves like `self == other`. + /// At runtime this function behaves like `Some(self == other)`. /// However, in some contexts (e.g., compile-time evaluation), /// it is not always possible to determine equality of two pointers, so this function may - /// spuriously return `false` for pointers that later actually turn out to be equal. - /// But when it returns `true`, the pointers are guaranteed to be equal. - /// - /// This function is the mirror of [`guaranteed_ne`], but not its inverse. There are pointer - /// comparisons for which both functions return `false`. - /// - /// [`guaranteed_ne`]: #method.guaranteed_ne + /// spuriously return `None` for pointers that later actually turn out to have its equality known. + /// But when it returns `Some`, the pointers' equality is guaranteed to be known. /// - /// The return value may change depending on the compiler version and unsafe code might not + /// The return value may change from `Some` to `None` and vice versa depending on the compiler + /// version and unsafe code must not /// rely on the result of this function for soundness. It is suggested to only use this function - /// for performance optimizations where spurious `false` return values by this function do not + /// for performance optimizations where spurious `None` return values by this function do not /// affect the outcome, but just the performance. /// The consequences of using this method to make runtime and compile-time code behave /// differently have not been explored. This method should not be used to introduce such @@ -719,29 +718,25 @@ impl<T: ?Sized> *mut T { #[unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[inline] - pub const fn guaranteed_eq(self, other: *mut T) -> bool + pub const fn guaranteed_eq(self, other: *mut T) -> Option<bool> where T: Sized, { - intrinsics::ptr_guaranteed_eq(self as *const _, other as *const _) + (self as *const T).guaranteed_eq(other as _) } - /// Returns whether two pointers are guaranteed to be unequal. + /// Returns whether two pointers are guaranteed to be inequal. /// - /// At runtime this function behaves like `self != other`. + /// At runtime this function behaves like `Some(self == other)`. /// However, in some contexts (e.g., compile-time evaluation), - /// it is not always possible to determine the inequality of two pointers, so this function may - /// spuriously return `false` for pointers that later actually turn out to be unequal. - /// But when it returns `true`, the pointers are guaranteed to be unequal. - /// - /// This function is the mirror of [`guaranteed_eq`], but not its inverse. There are pointer - /// comparisons for which both functions return `false`. - /// - /// [`guaranteed_eq`]: #method.guaranteed_eq + /// it is not always possible to determine inequality of two pointers, so this function may + /// spuriously return `None` for pointers that later actually turn out to have its inequality known. + /// But when it returns `Some`, the pointers' inequality is guaranteed to be known. /// - /// The return value may change depending on the compiler version and unsafe code might not + /// The return value may change from `Some` to `None` and vice versa depending on the compiler + /// version and unsafe code must not /// rely on the result of this function for soundness. It is suggested to only use this function - /// for performance optimizations where spurious `false` return values by this function do not + /// for performance optimizations where spurious `None` return values by this function do not /// affect the outcome, but just the performance. /// The consequences of using this method to make runtime and compile-time code behave /// differently have not been explored. This method should not be used to introduce such @@ -750,11 +745,11 @@ impl<T: ?Sized> *mut T { #[unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[inline] - pub const unsafe fn guaranteed_ne(self, other: *mut T) -> bool + pub const fn guaranteed_ne(self, other: *mut T) -> Option<bool> where T: Sized, { - intrinsics::ptr_guaranteed_ne(self as *const _, other as *const _) + (self as *const T).guaranteed_ne(other as _) } /// Calculates the distance between two pointers. The returned value is in diff --git a/src/test/ui/consts/miri_unleashed/slice_eq.rs b/src/test/ui/consts/miri_unleashed/slice_eq.rs index fd843105daf..83e10bf1213 100644 --- a/src/test/ui/consts/miri_unleashed/slice_eq.rs +++ b/src/test/ui/consts/miri_unleashed/slice_eq.rs @@ -4,14 +4,10 @@ #![feature(const_raw_ptr_comparison)] const EMPTY_SLICE: &[i32] = &[]; -const EMPTY_EQ: bool = EMPTY_SLICE.as_ptr().guaranteed_eq(&[] as *const _); -const EMPTY_EQ2: bool = EMPTY_SLICE.as_ptr().guaranteed_ne(&[] as *const _); -const EMPTY_NE: bool = EMPTY_SLICE.as_ptr().guaranteed_ne(&[1] as *const _); -const EMPTY_NE2: bool = EMPTY_SLICE.as_ptr().guaranteed_eq(&[1] as *const _); +const EMPTY_EQ: Option<bool> = EMPTY_SLICE.as_ptr().guaranteed_eq(&[] as *const _); +const EMPTY_EQ2: Option<bool> = EMPTY_SLICE.as_ptr().guaranteed_eq(&[1] as *const _); fn main() { - assert!(!EMPTY_EQ); - assert!(!EMPTY_EQ2); - assert!(!EMPTY_NE); - assert!(!EMPTY_NE2); + assert!(EMPTY_EQ.is_none()); + assert!(EMPTY_EQ2.is_none()); } diff --git a/src/test/ui/consts/ptr_comparisons.rs b/src/test/ui/consts/ptr_comparisons.rs index 20233db09c9..0a3c2d4bedc 100644 --- a/src/test/ui/consts/ptr_comparisons.rs +++ b/src/test/ui/consts/ptr_comparisons.rs @@ -14,38 +14,30 @@ const FOO: &usize = &42; macro_rules! check { (eq, $a:expr, $b:expr) => { pub const _: () = - assert!(std::intrinsics::ptr_guaranteed_eq($a as *const u8, $b as *const u8)); + assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 1); }; (ne, $a:expr, $b:expr) => { pub const _: () = - assert!(std::intrinsics::ptr_guaranteed_ne($a as *const u8, $b as *const u8)); + assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 0); }; - (!eq, $a:expr, $b:expr) => { + (!, $a:expr, $b:expr) => { pub const _: () = - assert!(!std::intrinsics::ptr_guaranteed_eq($a as *const u8, $b as *const u8)); - }; - (!ne, $a:expr, $b:expr) => { - pub const _: () = - assert!(!std::intrinsics::ptr_guaranteed_ne($a as *const u8, $b as *const u8)); + assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 2); }; } check!(eq, 0, 0); check!(ne, 0, 1); -check!(!eq, 0, 1); -check!(!ne, 0, 0); check!(ne, FOO as *const _, 0); -check!(!eq, FOO as *const _, 0); +check!(ne, unsafe { (FOO as *const usize).offset(1) }, 0); +check!(ne, unsafe { (FOO as *const usize as *const u8).offset(3) }, 0); + // We want pointers to be equal to themselves, but aren't checking this yet because // there are some open questions (e.g. whether function pointers to the same function // compare equal, they don't necessarily at runtime). // The case tested here should work eventually, but does not work yet. -check!(!eq, FOO as *const _, FOO as *const _); -check!(ne, unsafe { (FOO as *const usize).offset(1) }, 0); -check!(!eq, unsafe { (FOO as *const usize).offset(1) }, 0); +check!(!, FOO as *const _, FOO as *const _); -check!(ne, unsafe { (FOO as *const usize as *const u8).offset(3) }, 0); -check!(!eq, unsafe { (FOO as *const usize as *const u8).offset(3) }, 0); /////////////////////////////////////////////////////////////////////////////// // If any of the below start compiling, make sure to add a `check` test for it. diff --git a/src/test/ui/consts/ptr_comparisons.stderr b/src/test/ui/consts/ptr_comparisons.stderr index 1d47f243f01..3de2aba5b05 100644 --- a/src/test/ui/consts/ptr_comparisons.stderr +++ b/src/test/ui/consts/ptr_comparisons.stderr @@ -7,19 +7,19 @@ LL | unsafe { intrinsics::offset(self, count) } | out-of-bounds pointer arithmetic: alloc3 has size $WORD, so pointer to $TWO_WORDS bytes starting at offset 0 is out-of-bounds | inside `ptr::const_ptr::<impl *const usize>::offset` at $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL | - ::: $DIR/ptr_comparisons.rs:58:34 + ::: $DIR/ptr_comparisons.rs:50:34 | LL | const _: *const usize = unsafe { (FOO as *const usize).offset(2) }; - | ------------------------------- inside `_` at $DIR/ptr_comparisons.rs:58:34 + | ------------------------------- inside `_` at $DIR/ptr_comparisons.rs:50:34 error[E0080]: evaluation of constant value failed - --> $DIR/ptr_comparisons.rs:61:33 + --> $DIR/ptr_comparisons.rs:53:33 | LL | unsafe { std::ptr::addr_of!((*(FOO as *const usize as *const [u8; 1000]))[999]) }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ dereferencing pointer failed: alloc3 has size $WORD, so pointer to 1000 bytes starting at offset 0 is out-of-bounds error: any use of this value will cause an error - --> $DIR/ptr_comparisons.rs:65:27 + --> $DIR/ptr_comparisons.rs:57:27 | LL | const _: usize = unsafe { std::mem::transmute::<*const usize, usize>(FOO) + 4 }; | -------------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unable to turn pointer into raw bytes @@ -31,7 +31,7 @@ LL | const _: usize = unsafe { std::mem::transmute::<*const usize, usize>(FOO) + = help: the absolute address of a pointer is not known at compile-time, so such operations are not supported error: any use of this value will cause an error - --> $DIR/ptr_comparisons.rs:70:27 + --> $DIR/ptr_comparisons.rs:62:27 | LL | const _: usize = unsafe { *std::mem::transmute::<&&usize, &usize>(&FOO) + 4 }; | -------------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unable to turn pointer into raw bytes @@ -46,7 +46,7 @@ error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0080`. Future incompatibility report: Future breakage diagnostic: error: any use of this value will cause an error - --> $DIR/ptr_comparisons.rs:65:27 + --> $DIR/ptr_comparisons.rs:57:27 | LL | const _: usize = unsafe { std::mem::transmute::<*const usize, usize>(FOO) + 4 }; | -------------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unable to turn pointer into raw bytes @@ -59,7 +59,7 @@ LL | const _: usize = unsafe { std::mem::transmute::<*const usize, usize>(FOO) + Future breakage diagnostic: error: any use of this value will cause an error - --> $DIR/ptr_comparisons.rs:70:27 + --> $DIR/ptr_comparisons.rs:62:27 | LL | const _: usize = unsafe { *std::mem::transmute::<&&usize, &usize>(&FOO) + 4 }; | -------------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unable to turn pointer into raw bytes |