1 files changed, 125 insertions, 0 deletions
diff --git a/src/test/ui/consts/offset_from_ub.rs b/src/test/ui/consts/offset_from_ub.rs
new file mode 100644
index 000000000..1f29a6905
--- /dev/null
+++ b/src/test/ui/consts/offset_from_ub.rs
@@ -0,0 +1,125 @@
+#![feature(const_ptr_offset_from)]
+#![feature(core_intrinsics)]
+
+use std::intrinsics::{ptr_offset_from, ptr_offset_from_unsigned};
+use std::ptr;
+
+#[repr(C)]
+struct Struct {
+    data: u8,
+    field: u8,
+}
+
+pub const DIFFERENT_ALLOC: usize = {
+    let uninit = std::mem::MaybeUninit::<Struct>::uninit();
+    let base_ptr: *const Struct = &uninit as *const _ as *const Struct;
+    let uninit2 = std::mem::MaybeUninit::<Struct>::uninit();
+    let field_ptr: *const Struct = &uninit2 as *const _ as *const Struct;
+    let offset = unsafe { ptr_offset_from(field_ptr, base_ptr) }; //~ERROR evaluation of constant value failed
+    //~| pointers into different allocations
+    offset as usize
+};
+
+pub const NOT_PTR: usize = {
+    unsafe { (42 as *const u8).offset_from(&5u8) as usize }
+};
+
+pub const NOT_MULTIPLE_OF_SIZE: isize = {
+    let data = [5u8, 6, 7];
+    let base_ptr = data.as_ptr();
+    let field_ptr = &data[1] as *const u8 as *const u16;
+    unsafe { ptr_offset_from(field_ptr, base_ptr as *const u16) } //~ERROR evaluation of constant value failed
+    //~| 1_isize cannot be divided by 2_isize without remainder
+};
+
+pub const OFFSET_FROM_NULL: isize = {
+    let ptr = 0 as *const u8;
+    unsafe { ptr_offset_from(ptr, ptr) } //~ERROR evaluation of constant value failed
+    //~| null pointer is a dangling pointer
+};
+
+pub const DIFFERENT_INT: isize = { // offset_from with two different integers: like DIFFERENT_ALLOC
+    let ptr1 = 8 as *const u8;
+    let ptr2 = 16 as *const u8;
+    unsafe { ptr_offset_from(ptr2, ptr1) } //~ERROR evaluation of constant value failed
+    //~| 0x8[noalloc] is a dangling pointer
+};
+
+const OUT_OF_BOUNDS_1: isize = {
+    let start_ptr = &4 as *const _ as *const u8;
+    let length = 10;
+    let end_ptr = (start_ptr).wrapping_add(length);
+    // First ptr is out of bounds
+    unsafe { ptr_offset_from(end_ptr, start_ptr) } //~ERROR evaluation of constant value failed
+    //~| pointer to 10 bytes starting at offset 0 is out-of-bounds
+};
+
+const OUT_OF_BOUNDS_2: isize = {
+    let start_ptr = &4 as *const _ as *const u8;
+    let length = 10;
+    let end_ptr = (start_ptr).wrapping_add(length);
+    // Second ptr is out of bounds
+    unsafe { ptr_offset_from(start_ptr, end_ptr) } //~ERROR evaluation of constant value failed
+    //~| pointer to 10 bytes starting at offset 0 is out-of-bounds
+};
+
+const OUT_OF_BOUNDS_SAME: isize = {
+    let start_ptr = &4 as *const _ as *const u8;
+    let length = 10;
+    let end_ptr = (start_ptr).wrapping_add(length);
+    unsafe { ptr_offset_from(end_ptr, end_ptr) } //~ERROR evaluation of constant value failed
+    //~| pointer at offset 10 is out-of-bounds
+};
+
+pub const DIFFERENT_ALLOC_UNSIGNED: usize = {
+    let uninit = std::mem::MaybeUninit::<Struct>::uninit();
+    let base_ptr: *const Struct = &uninit as *const _ as *const Struct;
+    let uninit2 = std::mem::MaybeUninit::<Struct>::uninit();
+    let field_ptr: *const Struct = &uninit2 as *const _ as *const Struct;
+    unsafe { ptr_offset_from_unsigned(field_ptr, base_ptr) } //~ERROR evaluation of constant value failed
+    //~| pointers into different allocations
+};
+
+pub const TOO_FAR_APART1: isize = {
+    let ptr1 = ptr::null::<u8>();
+    let ptr2 = ptr1.wrapping_add(isize::MAX as usize + 42);
+    unsafe { ptr_offset_from(ptr2, ptr1) } //~ERROR evaluation of constant value failed
+    //~| too far ahead
+};
+pub const TOO_FAR_APART2: isize = {
+    let ptr1 = ptr::null::<u8>();
+    let ptr2 = ptr1.wrapping_add(isize::MAX as usize + 42);
+    unsafe { ptr_offset_from(ptr1, ptr2) } //~ERROR evaluation of constant value failed
+    //~| too far before
+};
+
+const WRONG_ORDER_UNSIGNED: usize = {
+    let a = ['a', 'b', 'c'];
+    let p = a.as_ptr();
+    unsafe { ptr_offset_from_unsigned(p, p.add(2) ) } //~ERROR evaluation of constant value failed
+    //~| first pointer has smaller offset than second: 0 < 8
+};
+pub const TOO_FAR_APART_UNSIGNED: usize = {
+    let ptr1 = ptr::null::<u8>();
+    let ptr2 = ptr1.wrapping_add(isize::MAX as usize + 42);
+    // This would fit into a `usize` but we still don't allow it.
+    unsafe { ptr_offset_from_unsigned(ptr2, ptr1) } //~ERROR evaluation of constant value failed
+    //~| too far ahead
+};
+
+// These do NOT complain that pointers are too far apart; they pass that check (to then fail the
+// next one).
+pub const OFFSET_VERY_FAR1: isize = {
+    let ptr1 = ptr::null::<u8>();
+    let ptr2 = ptr1.wrapping_offset(isize::MAX);
+    unsafe { ptr2.offset_from(ptr1) }
+    //~^ inside
+};
+pub const OFFSET_VERY_FAR2: isize = {
+    let ptr1 = ptr::null::<u8>();
+    let ptr2 = ptr1.wrapping_offset(isize::MAX);
+    unsafe { ptr1.offset_from(ptr2.wrapping_offset(1)) }
+    //~^ inside
+};
+
+fn main() {}