diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs index ac01d436bdc..054b65f0e1a 100644 --- a/src/librustc_mir/interpret/eval_context.rs +++ b/src/librustc_mir/interpret/eval_context.rs @@ -442,27 +442,30 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { // Issue #27023: must add any necessary padding to `size` // (to make it a multiple of `align`) before returning it. - // - // Namely, the returned size should be, in C notation: - // - // `size + ((size & (align-1)) ? align : 0)` - // - // emulated via the semi-standard fast bit trick: - // - // `(size + (align-1)) & -align` + let size = size.align_to(align); - Ok(Some((size.align_to(align), align))) + // Check if this brought us over the size limit. + if size.bytes() >= self.tcx.data_layout().obj_size_bound() { + throw_ub_format!("wide pointer metadata contains invalid information: \ + total size is bigger than largest supported object"); + } + Ok(Some((size, align))) } ty::Dynamic(..) => { let vtable = metadata.expect("dyn trait fat ptr must have vtable"); - // the second entry in the vtable is the dynamic size of the object. + // Read size and align from vtable (already checks size). Ok(Some(self.read_size_and_align_from_vtable(vtable)?)) } ty::Slice(_) | ty::Str => { let len = metadata.expect("slice fat ptr must have vtable").to_usize(self)?; let elem = layout.field(self, 0)?; - Ok(Some((elem.size * len, elem.align.abi))) + + // Make sure the slice is not too big. + let size = elem.size.checked_mul(len, &*self.tcx) + .ok_or_else(|| err_ub_format!("invalid slice: \ + total size is bigger than largest supported object"))?; + Ok(Some((size, elem.align.abi))) } ty::Foreign(_) => { diff --git a/src/librustc_mir/interpret/traits.rs b/src/librustc_mir/interpret/traits.rs index 34a10de7de7..10b767ebba1 100644 --- a/src/librustc_mir/interpret/traits.rs +++ b/src/librustc_mir/interpret/traits.rs @@ -1,5 +1,5 @@ use rustc::ty::{self, Ty, Instance, TypeFoldable}; -use rustc::ty::layout::{Size, Align, LayoutOf}; +use rustc::ty::layout::{Size, Align, LayoutOf, HasDataLayout}; use rustc::mir::interpret::{Scalar, Pointer, InterpResult, PointerArithmetic,}; use super::{InterpCx, Machine, MemoryKind, FnVal}; @@ -151,6 +151,11 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { vtable.offset(pointer_size * 2, self)?, )?.not_undef()?; let align = self.force_bits(align, pointer_size)? as u64; + + if size >= self.tcx.data_layout().obj_size_bound() { + throw_ub_format!("invalid vtable: \ + size is bigger than largest supported object"); + } Ok((Size::from_bytes(size), Align::from_bytes(align).unwrap())) } } diff --git a/src/librustc_mir/interpret/validity.rs b/src/librustc_mir/interpret/validity.rs index c2505547c5b..3e14ba3efcc 100644 --- a/src/librustc_mir/interpret/validity.rs +++ b/src/librustc_mir/interpret/validity.rs @@ -1,3 +1,9 @@ +//! Check the validity invariant of a given value, and tell the user +//! where in the value it got violated. +//! In const context, this goes even further and tries to approximate const safety. +//! That's useful because it means other passes (e.g. promotion) can rely on `const`s +//! to be const-safe. + use std::fmt::Write; use std::ops::RangeInclusive; diff --git a/src/test/ui/consts/const-eval/dangling.rs b/src/test/ui/consts/const-eval/dangling.rs new file mode 100644 index 00000000000..b5d72d46f28 --- /dev/null +++ b/src/test/ui/consts/const-eval/dangling.rs @@ -0,0 +1,13 @@ +#![feature(const_transmute, const_raw_ptr_deref)] + +use std::{mem, usize}; + +// Make sure we error with the right kind of error on a too large slice. +const TEST: () = { unsafe { //~ NOTE + let slice: *const [u8] = mem::transmute((1usize, usize::MAX)); + let _val = &*slice; //~ ERROR: any use of this value will cause an error + //~^ NOTE: total size is bigger than largest supported object + //~^^ on by default +} }; + +fn main() {} diff --git a/src/test/ui/consts/const-eval/dangling.stderr b/src/test/ui/consts/const-eval/dangling.stderr new file mode 100644 index 00000000000..286de080097 --- /dev/null +++ b/src/test/ui/consts/const-eval/dangling.stderr @@ -0,0 +1,16 @@ +error: any use of this value will cause an error + --> $DIR/dangling.rs:8:16 + | +LL | / const TEST: () = { unsafe { +LL | | let slice: *const [u8] = mem::transmute((1usize, usize::MAX)); +LL | | let _val = &*slice; + | | ^^^^^^^ invalid slice: total size is bigger than largest supported object +LL | | +LL | | +LL | | } }; + | |____- + | + = note: `#[deny(const_err)]` on by default + +error: aborting due to previous error + diff --git a/src/test/ui/consts/const-eval/ub-wide-ptr.rs b/src/test/ui/consts/const-eval/ub-wide-ptr.rs index 765ed60ee97..1f810c40572 100644 --- a/src/test/ui/consts/const-eval/ub-wide-ptr.rs +++ b/src/test/ui/consts/const-eval/ub-wide-ptr.rs @@ -7,6 +7,7 @@ // normalize-stderr-test "allocation \d+" -> "allocation N" // normalize-stderr-test "size \d+" -> "size N" +#[repr(C)] union BoolTransmute { val: u8, bl: bool, @@ -26,6 +27,7 @@ struct BadSliceRepr { len: &'static u8, } +#[repr(C)] union SliceTransmute { repr: SliceRepr, bad: BadSliceRepr, @@ -58,6 +60,7 @@ struct BadDynRepr { vtable: usize, } +#[repr(C)] union DynTransmute { repr: DynRepr, repr2: DynRepr2, @@ -91,10 +94,10 @@ const MY_STR_LENGTH_PTR: &MyStr = unsafe { SliceTransmute { bad: BadSliceRepr { //~^ ERROR it is undefined behavior to use this value // invalid UTF-8 -const J1: &str = unsafe { SliceTransmute { slice: &[0xFF] }.str }; +const STR_NO_UTF8: &str = unsafe { SliceTransmute { slice: &[0xFF] }.str }; //~^ ERROR it is undefined behavior to use this value // invalid UTF-8 in user-defined str-like -const J2: &MyStr = unsafe { SliceTransmute { slice: &[0xFF] }.my_str }; +const MYSTR_NO_UTF8: &MyStr = unsafe { SliceTransmute { slice: &[0xFF] }.my_str }; //~^ ERROR it is undefined behavior to use this value // # slice @@ -111,16 +114,16 @@ const SLICE_LENGTH_PTR: &[u8] = unsafe { SliceTransmute { bad: BadSliceRepr { pt //~^ ERROR it is undefined behavior to use this value // bad data *inside* the slice -const H: &[bool] = &[unsafe { BoolTransmute { val: 3 }.bl }]; +const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { BoolTransmute { val: 3 }.bl }]; //~^ ERROR it is undefined behavior to use this value // good MySliceBool -const I1: &MySliceBool = &MySlice(true, [false]); +const MYSLICE_GOOD: &MySliceBool = &MySlice(true, [false]); // bad: sized field is not okay -const I2: &MySliceBool = &MySlice(unsafe { BoolTransmute { val: 3 }.bl }, [false]); +const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { BoolTransmute { val: 3 }.bl }, [false]); //~^ ERROR it is undefined behavior to use this value // bad: unsized part is not okay -const I3: &MySliceBool = &MySlice(true, [unsafe { BoolTransmute { val: 3 }.bl }]); +const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { BoolTransmute { val: 3 }.bl }]); //~^ ERROR it is undefined behavior to use this value // # raw slice @@ -132,17 +135,17 @@ const RAW_SLICE_LENGTH_UNINIT: *const [u8] = unsafe { SliceTransmute { addr: 42 // # trait object // bad trait object -const D: &dyn Trait = unsafe { DynTransmute { repr: DynRepr { ptr: &92, vtable: &3 } }.rust}; +const TRAIT_OBJ_SHORT_VTABLE_1: &dyn Trait = unsafe { DynTransmute { repr: DynRepr { ptr: &92, vtable: &3 } }.rust}; //~^ ERROR it is undefined behavior to use this value // bad trait object -const E: &dyn Trait = unsafe { DynTransmute { repr2: DynRepr2 { ptr: &92, vtable: &3 } }.rust}; +const TRAIT_OBJ_SHORT_VTABLE_2: &dyn Trait = unsafe { DynTransmute { repr2: DynRepr2 { ptr: &92, vtable: &3 } }.rust}; //~^ ERROR it is undefined behavior to use this value // bad trait object -const F: &dyn Trait = unsafe { DynTransmute { bad: BadDynRepr { ptr: &92, vtable: 3 } }.rust}; +const TRAIT_OBJ_INT_VTABLE: &dyn Trait = unsafe { DynTransmute { bad: BadDynRepr { ptr: &92, vtable: 3 } }.rust}; //~^ ERROR it is undefined behavior to use this value // bad data *inside* the trait object -const G: &dyn Trait = &unsafe { BoolTransmute { val: 3 }.bl }; +const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = &unsafe { BoolTransmute { val: 3 }.bl }; //~^ ERROR it is undefined behavior to use this value // # raw trait object diff --git a/src/test/ui/consts/const-eval/ub-wide-ptr.stderr b/src/test/ui/consts/const-eval/ub-wide-ptr.stderr index 88d8af80261..aadabc323fb 100644 --- a/src/test/ui/consts/const-eval/ub-wide-ptr.stderr +++ b/src/test/ui/consts/const-eval/ub-wide-ptr.stderr @@ -1,5 +1,5 @@ error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:84:1 + --> $DIR/ub-wide-ptr.rs:87:1 | LL | const STR_TOO_LONG: &str = unsafe { SliceTransmute { repr: SliceRepr { ptr: &42, len: 999 } }.str}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling reference (not entirely in bounds) @@ -7,7 +7,7 @@ LL | const STR_TOO_LONG: &str = unsafe { SliceTransmute { repr: SliceRepr { ptr: = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:87:1 + --> $DIR/ub-wide-ptr.rs:90:1 | LL | const STR_LENGTH_PTR: &str = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.str}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-integer slice length in wide pointer @@ -15,31 +15,31 @@ LL | const STR_LENGTH_PTR: &str = unsafe { SliceTransmute { bad: BadSliceRepr { = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:90:1 + --> $DIR/ub-wide-ptr.rs:93:1 | LL | const MY_STR_LENGTH_PTR: &MyStr = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.my_str}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-integer slice length in wide pointer | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior -error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:94:1 - | -LL | const J1: &str = unsafe { SliceTransmute { slice: &[0xFF] }.str }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized or non-UTF-8 data in str at . - | - = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior - error[E0080]: it is undefined behavior to use this value --> $DIR/ub-wide-ptr.rs:97:1 | -LL | const J2: &MyStr = unsafe { SliceTransmute { slice: &[0xFF] }.my_str }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized or non-UTF-8 data in str at ..0 +LL | const STR_NO_UTF8: &str = unsafe { SliceTransmute { slice: &[0xFF] }.str }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized or non-UTF-8 data in str at . | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:104:1 + --> $DIR/ub-wide-ptr.rs:100:1 + | +LL | const MYSTR_NO_UTF8: &MyStr = unsafe { SliceTransmute { slice: &[0xFF] }.my_str }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized or non-UTF-8 data in str at ..0 + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior + +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:107:1 | LL | const SLICE_LENGTH_UNINIT: &[u8] = unsafe { SliceTransmute { addr: 42 }.slice}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized data in wide pointer metadata @@ -47,7 +47,7 @@ LL | const SLICE_LENGTH_UNINIT: &[u8] = unsafe { SliceTransmute { addr: 42 }.sli = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:107:1 + --> $DIR/ub-wide-ptr.rs:110:1 | LL | const SLICE_TOO_LONG: &[u8] = unsafe { SliceTransmute { repr: SliceRepr { ptr: &42, len: 999 } }.slice}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling reference (not entirely in bounds) @@ -55,7 +55,7 @@ LL | const SLICE_TOO_LONG: &[u8] = unsafe { SliceTransmute { repr: SliceRepr { p = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:110:1 + --> $DIR/ub-wide-ptr.rs:113:1 | LL | const SLICE_LENGTH_PTR: &[u8] = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.slice}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-integer slice length in wide pointer @@ -63,71 +63,71 @@ LL | const SLICE_LENGTH_PTR: &[u8] = unsafe { SliceTransmute { bad: BadSliceRepr = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:114:1 + --> $DIR/ub-wide-ptr.rs:117:1 | -LL | const H: &[bool] = &[unsafe { BoolTransmute { val: 3 }.bl }]; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at .[0], but expected something less or equal to 1 - | - = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior - -error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:120:1 - | -LL | const I2: &MySliceBool = &MySlice(unsafe { BoolTransmute { val: 3 }.bl }, [false]); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at ..0, but expected something less or equal to 1 +LL | const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { BoolTransmute { val: 3 }.bl }]; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at .[0], but expected something less or equal to 1 | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value --> $DIR/ub-wide-ptr.rs:123:1 | -LL | const I3: &MySliceBool = &MySlice(true, [unsafe { BoolTransmute { val: 3 }.bl }]); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at ..1[0], but expected something less or equal to 1 +LL | const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { BoolTransmute { val: 3 }.bl }, [false]); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at ..0, but expected something less or equal to 1 | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:130:1 + --> $DIR/ub-wide-ptr.rs:126:1 + | +LL | const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { BoolTransmute { val: 3 }.bl }]); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at ..1[0], but expected something less or equal to 1 + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior + +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:133:1 | LL | const RAW_SLICE_LENGTH_UNINIT: *const [u8] = unsafe { SliceTransmute { addr: 42 }.raw_slice}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized data in wide pointer metadata | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior -error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:135:1 - | -LL | const D: &dyn Trait = unsafe { DynTransmute { repr: DynRepr { ptr: &92, vtable: &3 } }.rust}; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling or unaligned vtable pointer in wide pointer or too small vtable - | - = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior - error[E0080]: it is undefined behavior to use this value --> $DIR/ub-wide-ptr.rs:138:1 | -LL | const E: &dyn Trait = unsafe { DynTransmute { repr2: DynRepr2 { ptr: &92, vtable: &3 } }.rust}; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling or unaligned vtable pointer in wide pointer or too small vtable +LL | const TRAIT_OBJ_SHORT_VTABLE_1: &dyn Trait = unsafe { DynTransmute { repr: DynRepr { ptr: &92, vtable: &3 } }.rust}; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling or unaligned vtable pointer in wide pointer or too small vtable | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value --> $DIR/ub-wide-ptr.rs:141:1 | -LL | const F: &dyn Trait = unsafe { DynTransmute { bad: BadDynRepr { ptr: &92, vtable: 3 } }.rust}; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling or unaligned vtable pointer in wide pointer or too small vtable +LL | const TRAIT_OBJ_SHORT_VTABLE_2: &dyn Trait = unsafe { DynTransmute { repr2: DynRepr2 { ptr: &92, vtable: &3 } }.rust}; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling or unaligned vtable pointer in wide pointer or too small vtable | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:145:1 + --> $DIR/ub-wide-ptr.rs:144:1 | -LL | const G: &dyn Trait = &unsafe { BoolTransmute { val: 3 }.bl }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at .., but expected something less or equal to 1 +LL | const TRAIT_OBJ_INT_VTABLE: &dyn Trait = unsafe { DynTransmute { bad: BadDynRepr { ptr: &92, vtable: 3 } }.rust}; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling or unaligned vtable pointer in wide pointer or too small vtable | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:149:1 + --> $DIR/ub-wide-ptr.rs:148:1 + | +LL | const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = &unsafe { BoolTransmute { val: 3 }.bl }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at .., but expected something less or equal to 1 + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior + +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:152:1 | LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { DynTransmute { bad: BadDynRepr { ptr: &92, vtable: 0 } }.rust}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling or unaligned vtable pointer in wide pointer or too small vtable @@ -135,7 +135,7 @@ LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { DynTransmute { = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-wide-ptr.rs:151:1 + --> $DIR/ub-wide-ptr.rs:154:1 | LL | const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { DynTransmute { repr2: DynRepr2 { ptr: &92, vtable: &3 } }.raw_rust}; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered dangling or unaligned vtable pointer in wide pointer or too small vtable