1 files changed, 263 insertions, 0 deletions
diff --git a/tests/ui/consts/const-eval/raw-bytes.rs b/tests/ui/consts/const-eval/raw-bytes.rs
new file mode 100644
index 000000000..6c1238c0a
--- /dev/null
+++ b/tests/ui/consts/const-eval/raw-bytes.rs
@@ -0,0 +1,263 @@
+// stderr-per-bitwidth
+// ignore-endian-big
+// ignore-tidy-linelength
+// normalize-stderr-test "╾─*a(lloc)?[0-9]+(\+[a-z0-9]+)?─*╼" -> "╾ALLOC_ID$2╼"
+// normalize-stderr-test "alloc\d+" -> "allocN"
+#![feature(never_type, rustc_attrs, ptr_metadata, slice_from_ptr_range, const_slice_from_ptr_range)]
+#![allow(invalid_value)]
+
+use std::mem;
+use std::alloc::Layout;
+use std::ptr::NonNull;
+use std::num::{NonZeroU8, NonZeroUsize};
+use std::slice::{from_ptr_range, from_raw_parts};
+
+#[repr(usize)]
+#[derive(Copy, Clone)]
+enum Enum {
+    A = 0,
+}
+const BAD_ENUM: Enum = unsafe { mem::transmute(1usize) };
+//~^ ERROR is undefined behavior
+
+#[repr(usize)]
+#[derive(Copy, Clone)]
+enum Enum2 {
+    A = 2,
+}
+const BAD_ENUM2: Enum2 = unsafe { mem::transmute(0usize) };
+//~^ ERROR is undefined behavior
+
+#[derive(Copy, Clone)]
+enum Never {}
+
+// An enum with 3 variants of which some are uninhabited -- so the uninhabited variants *do*
+// have a discriminant.
+enum UninhDiscriminant {
+    A,
+    B(!),
+    C,
+    D(Never),
+}
+const BAD_UNINHABITED_VARIANT1: UninhDiscriminant = unsafe { mem::transmute(1u8) };
+//~^ ERROR is undefined behavior
+const BAD_UNINHABITED_VARIANT2: UninhDiscriminant = unsafe { mem::transmute(3u8) };
+//~^ ERROR is undefined behavior
+
+// Invalid enum field content (mostly to test printing of paths for enum tuple
+// variants and tuples).
+// Need to create something which does not clash with enum layout optimizations.
+const BAD_OPTION_CHAR: Option<(char, char)> = Some(('x', unsafe { mem::transmute(!0u32) }));
+//~^ ERROR is undefined behavior
+
+
+const NULL_PTR: NonNull<u8> = unsafe { mem::transmute(0usize) };
+//~^ ERROR it is undefined behavior to use this value
+
+const NULL_U8: NonZeroU8 = unsafe { mem::transmute(0u8) };
+//~^ ERROR it is undefined behavior to use this value
+const NULL_USIZE: NonZeroUsize = unsafe { mem::transmute(0usize) };
+//~^ ERROR it is undefined behavior to use this value
+
+#[rustc_layout_scalar_valid_range_start(10)]
+#[rustc_layout_scalar_valid_range_end(30)]
+struct RestrictedRange1(u32);
+const BAD_RANGE1: RestrictedRange1 = unsafe { RestrictedRange1(42) };
+//~^ ERROR it is undefined behavior to use this value
+
+#[rustc_layout_scalar_valid_range_start(30)]
+#[rustc_layout_scalar_valid_range_end(10)]
+struct RestrictedRange2(u32);
+const BAD_RANGE2: RestrictedRange2 = unsafe { RestrictedRange2(20) };
+//~^ ERROR it is undefined behavior to use this value
+
+const NULL_FAT_PTR: NonNull<dyn Send> = unsafe {
+//~^ ERROR it is undefined behavior to use this value
+    let x: &dyn Send = &42;
+    let meta = std::ptr::metadata(x);
+    mem::transmute((0_usize, meta))
+};
+
+
+const UNALIGNED: &u16 = unsafe { mem::transmute(&[0u8; 4]) };
+//~^ ERROR it is undefined behavior to use this value
+//~| constructing invalid value: encountered an unaligned reference (required 2 byte alignment but found 1)
+
+const UNALIGNED_BOX: Box<u16> = unsafe { mem::transmute(&[0u8; 4]) };
+//~^ ERROR it is undefined behavior to use this value
+//~| constructing invalid value: encountered an unaligned box (required 2 byte alignment but found 1)
+
+const NULL: &u16 = unsafe { mem::transmute(0usize) };
+//~^ ERROR it is undefined behavior to use this value
+
+const NULL_BOX: Box<u16> = unsafe { mem::transmute(0usize) };
+//~^ ERROR it is undefined behavior to use this value
+
+const USIZE_AS_REF: &'static u8 = unsafe { mem::transmute(1337usize) };
+//~^ ERROR it is undefined behavior to use this value
+
+const USIZE_AS_BOX: Box<u8> = unsafe { mem::transmute(1337usize) };
+//~^ ERROR it is undefined behavior to use this value
+
+const NULL_FN_PTR: fn() = unsafe { mem::transmute(0usize) };
+//~^ ERROR it is undefined behavior to use this value
+const DANGLING_FN_PTR: fn() = unsafe { mem::transmute(13usize) };
+//~^ ERROR it is undefined behavior to use this value
+const DATA_FN_PTR: fn() = unsafe { mem::transmute(&13) };
+//~^ ERROR it is undefined behavior to use this value
+
+#[derive(Copy, Clone)]
+enum Bar {}
+
+const BAD_BAD_REF: &Bar = unsafe { mem::transmute(1usize) };
+//~^ ERROR it is undefined behavior to use this value
+
+
+/// A newtype wrapper to prevent MIR generation from inserting reborrows that would affect the error
+/// message.
+#[repr(transparent)]
+struct W<T>(T);
+
+#[repr(C)]
+union MaybeUninit<T: Copy> {
+    uninit: (),
+    init: T,
+}
+
+trait Trait {}
+impl Trait for bool {}
+
+// custom unsized type
+struct MyStr(str);
+
+// custom unsized type with sized fields
+struct MySlice<T: ?Sized>(bool, T);
+type MySliceBool = MySlice<[bool]>;
+
+const STR_TOO_LONG: &str = unsafe { mem::transmute((&42u8, 999usize)) };
+//~^ ERROR it is undefined behavior to use this value
+const NESTED_STR_MUCH_TOO_LONG: (&str,) = (unsafe { mem::transmute((&42, usize::MAX)) },);
+//~^ ERROR it is undefined behavior to use this value
+const MY_STR_MUCH_TOO_LONG: &MyStr = unsafe { mem::transmute((&42u8, usize::MAX)) };
+//~^ ERROR it is undefined behavior to use this value
+
+const STR_NO_INIT: &str = unsafe { mem::transmute::<&[_], _>(&[MaybeUninit::<u8> { uninit: () }]) };
+//~^ ERROR it is undefined behavior to use this value
+const MYSTR_NO_INIT: &MyStr = unsafe { mem::transmute::<&[_], _>(&[MaybeUninit::<u8> { uninit: () }]) };
+//~^ ERROR it is undefined behavior to use this value
+const MYSTR_NO_INIT_ISSUE83182: &MyStr = unsafe { mem::transmute::<&[_], _>(&[&()]) };
+//~^ ERROR: it is undefined behavior to use this value
+
+// # slice
+const SLICE_TOO_LONG: &[u8] = unsafe { mem::transmute((&42u8, 999usize)) };
+//~^ ERROR it is undefined behavior to use this value
+const SLICE_TOO_LONG_OVERFLOW: &[u32] = unsafe { mem::transmute((&42u32, isize::MAX)) };
+//~^ ERROR it is undefined behavior to use this value
+// bad slice box: length too big
+const SLICE_TOO_LONG_BOX: Box<[u8]> = unsafe { mem::transmute((&42u8, 999usize)) };
+//~^ ERROR it is undefined behavior to use this value
+// bad data *inside* the slice
+const SLICE_CONTENT_INVALID: &[bool] = &[unsafe { mem::transmute(3u8) }];
+//~^ ERROR it is undefined behavior to use this value
+//~| constant
+
+
+// bad: sized field is not okay
+const MYSLICE_PREFIX_BAD: &MySliceBool = &MySlice(unsafe { mem::transmute(3u8) }, [false]);
+//~^ ERROR it is undefined behavior to use this value
+//~| constant
+// bad: unsized part is not okay
+const MYSLICE_SUFFIX_BAD: &MySliceBool = &MySlice(true, [unsafe { mem::transmute(3u8) }]);
+//~^ ERROR it is undefined behavior to use this value
+//~| constant
+
+// bad trait object
+const TRAIT_OBJ_SHORT_VTABLE_1: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &3u8))) };
+//~^ ERROR it is undefined behavior to use this value
+//~| expected a vtable
+// bad trait object
+const TRAIT_OBJ_SHORT_VTABLE_2: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &3u64))) };
+//~^ ERROR it is undefined behavior to use this value
+//~| expected a vtable
+// bad trait object
+const TRAIT_OBJ_INT_VTABLE: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, 4usize))) };
+//~^ ERROR it is undefined behavior to use this value
+//~| expected a vtable
+const TRAIT_OBJ_BAD_DROP_FN_NOT_FN_PTR: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &[&42u8; 8]))) };
+//~^ ERROR it is undefined behavior to use this value
+//~| expected a vtable
+// bad data *inside* the trait object
+const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = unsafe { mem::transmute::<_, &bool>(&3u8) };
+//~^ ERROR it is undefined behavior to use this value
+//~| expected a boolean
+
+const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92u8, 0usize)) };
+//~^ ERROR it is undefined behavior to use this value
+const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) };
+//~^ ERROR it is undefined behavior to use this value
+
+
+// not ok, since alignment needs to be non-zero.
+const LAYOUT_INVALID_ZERO: Layout = unsafe { Layout::from_size_align_unchecked(0x1000, 0x00) };
+//~^ ERROR it is undefined behavior to use this value
+
+// not ok, since alignment needs to be a power of two.
+const LAYOUT_INVALID_THREE: Layout = unsafe { Layout::from_size_align_unchecked(9, 3) };
+//~^ ERROR it is undefined behavior to use this value
+
+
+const _: &[!; 1] = unsafe { &*(1_usize as *const [!; 1]) }; //~ ERROR undefined behavior
+const _: &[!] = unsafe { &*(1_usize as *const [!; 1]) }; //~ ERROR undefined behavior
+const _: &[!] = unsafe { &*(1_usize as *const [!; 42]) }; //~ ERROR undefined behavior
+
+
+// Reading uninitialized  data
+pub static S4: &[u8] = unsafe { from_raw_parts((&D1) as *const _ as _, 1) };
+//~^ ERROR: it is undefined behavior to use this value
+// Reinterpret pointers as integers (UB in CTFE.)
+pub static S5: &[u8] = unsafe { from_raw_parts((&D3) as *const _ as _, mem::size_of::<&u32>()) };
+//~^ ERROR: it is undefined behavior to use this value
+// Layout mismatch
+pub static S6: &[bool] = unsafe { from_raw_parts((&D0) as *const _ as _, 4) };
+//~^ ERROR: it is undefined behavior to use this value
+
+// Reading padding is not ok
+pub static S7: &[u16] = unsafe {
+    //~^ ERROR: it is undefined behavior to use this value
+    let ptr = (&D2 as *const Struct as *const u16).add(1);
+
+    from_raw_parts(ptr, 4)
+};
+
+pub static R4: &[u8] = unsafe {
+    //~^ ERROR: it is undefined behavior to use this value
+    let ptr = (&D1) as *const mem::MaybeUninit<&u32> as *const u8;
+    from_ptr_range(ptr..ptr.add(1))
+};
+pub static R5: &[u8] = unsafe {
+    //~^ ERROR: it is undefined behavior to use this value
+    let ptr = &D3 as *const &u32;
+    from_ptr_range(ptr.cast()..ptr.add(1).cast())
+};
+pub static R6: &[bool] = unsafe {
+    //~^ ERROR: it is undefined behavior to use this value
+    let ptr = &D0 as *const u32 as *const bool;
+    from_ptr_range(ptr..ptr.add(4))
+};
+
+const D0: u32 = 0x11111111; // Constant chosen for endianness-independent behavior.
+const D1: mem::MaybeUninit<&u32> = mem::MaybeUninit::uninit();
+const D2: Struct = Struct { a: 1, b: 2, c: 3, d: 4 };
+const D3: &u32 = &42;
+
+#[repr(C)]
+struct Struct {
+    a: u8,
+    // _pad: [mem::MaybeUninit<u8>; 3]
+    b: u32,
+    c: u16,
+    d: u8,
+    // _pad: [mem::MaybeUninit<u8>; 1]
+}
+
+fn main() {}