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// run-pass
// alloc::heap::reallocate test.
//
// Ideally this would be revised to use no_std, but for now it serves
// well enough to reproduce (and illustrate) the bug from #16687.
#![feature(allocator_api)]
#![feature(slice_ptr_get)]
use std::alloc::{handle_alloc_error, Allocator, Global, Layout};
use std::ptr::{self, NonNull};
fn main() {
unsafe {
assert!(test_triangle());
}
}
unsafe fn test_triangle() -> bool {
static COUNT: usize = 16;
let mut ascend = vec![ptr::null_mut(); COUNT];
let ascend = &mut *ascend;
static ALIGN: usize = 1;
// Checks that `ascend` forms triangle of ascending size formed
// from pairs of rows (where each pair of rows is equally sized),
// and the elements of the triangle match their row-pair index.
unsafe fn sanity_check(ascend: &[*mut u8]) {
for i in 0..COUNT / 2 {
let (p0, p1, size) = (ascend[2 * i], ascend[2 * i + 1], idx_to_size(i));
for j in 0..size {
assert_eq!(*p0.add(j), i as u8);
assert_eq!(*p1.add(j), i as u8);
}
}
}
static PRINT: bool = false;
unsafe fn allocate(layout: Layout) -> *mut u8 {
if PRINT {
println!("allocate({:?})", layout);
}
let ptr = Global.allocate(layout).unwrap_or_else(|_| handle_alloc_error(layout));
if PRINT {
println!("allocate({:?}) = {:?}", layout, ptr);
}
ptr.as_mut_ptr()
}
unsafe fn deallocate(ptr: *mut u8, layout: Layout) {
if PRINT {
println!("deallocate({:?}, {:?}", ptr, layout);
}
Global.deallocate(NonNull::new_unchecked(ptr), layout);
}
unsafe fn reallocate(ptr: *mut u8, old: Layout, new: Layout) -> *mut u8 {
if PRINT {
println!("reallocate({:?}, old={:?}, new={:?})", ptr, old, new);
}
let memory = if new.size() > old.size() {
Global.grow(NonNull::new_unchecked(ptr), old, new)
} else {
Global.shrink(NonNull::new_unchecked(ptr), old, new)
};
let ptr = memory.unwrap_or_else(|_| handle_alloc_error(new));
if PRINT {
println!("reallocate({:?}, old={:?}, new={:?}) = {:?}", ptr, old, new, ptr);
}
ptr.as_mut_ptr()
}
fn idx_to_size(i: usize) -> usize {
(i + 1) * 10
}
// Allocate pairs of rows that form a triangle shape. (Hope is
// that at least two rows will be allocated near each other, so
// that we trigger the bug (a buffer overrun) in an observable
// way.)
for i in 0..COUNT / 2 {
let size = idx_to_size(i);
ascend[2 * i] = allocate(Layout::from_size_align(size, ALIGN).unwrap());
ascend[2 * i + 1] = allocate(Layout::from_size_align(size, ALIGN).unwrap());
}
// Initialize each pair of rows to distinct value.
for i in 0..COUNT / 2 {
let (p0, p1, size) = (ascend[2 * i], ascend[2 * i + 1], idx_to_size(i));
for j in 0..size {
*p0.add(j) = i as u8;
*p1.add(j) = i as u8;
}
}
sanity_check(&*ascend);
test_1(ascend); // triangle -> square
test_2(ascend); // square -> triangle
test_3(ascend); // triangle -> square
test_4(ascend); // square -> triangle
for i in 0..COUNT / 2 {
let size = idx_to_size(i);
deallocate(ascend[2 * i], Layout::from_size_align(size, ALIGN).unwrap());
deallocate(ascend[2 * i + 1], Layout::from_size_align(size, ALIGN).unwrap());
}
return true;
// Test 1: turn the triangle into a square (in terms of
// allocation; initialized portion remains a triangle) by
// realloc'ing each row from top to bottom, and checking all the
// rows as we go.
unsafe fn test_1(ascend: &mut [*mut u8]) {
let new_size = idx_to_size(COUNT - 1);
let new = Layout::from_size_align(new_size, ALIGN).unwrap();
for i in 0..COUNT / 2 {
let (p0, p1, old_size) = (ascend[2 * i], ascend[2 * i + 1], idx_to_size(i));
assert!(old_size < new_size);
let old = Layout::from_size_align(old_size, ALIGN).unwrap();
ascend[2 * i] = reallocate(p0, old.clone(), new.clone());
sanity_check(&*ascend);
ascend[2 * i + 1] = reallocate(p1, old.clone(), new.clone());
sanity_check(&*ascend);
}
}
// Test 2: turn the square back into a triangle, top to bottom.
unsafe fn test_2(ascend: &mut [*mut u8]) {
let old_size = idx_to_size(COUNT - 1);
let old = Layout::from_size_align(old_size, ALIGN).unwrap();
for i in 0..COUNT / 2 {
let (p0, p1, new_size) = (ascend[2 * i], ascend[2 * i + 1], idx_to_size(i));
assert!(new_size < old_size);
let new = Layout::from_size_align(new_size, ALIGN).unwrap();
ascend[2 * i] = reallocate(p0, old.clone(), new.clone());
sanity_check(&*ascend);
ascend[2 * i + 1] = reallocate(p1, old.clone(), new.clone());
sanity_check(&*ascend);
}
}
// Test 3: turn triangle into a square, bottom to top.
unsafe fn test_3(ascend: &mut [*mut u8]) {
let new_size = idx_to_size(COUNT - 1);
let new = Layout::from_size_align(new_size, ALIGN).unwrap();
for i in (0..COUNT / 2).rev() {
let (p0, p1, old_size) = (ascend[2 * i], ascend[2 * i + 1], idx_to_size(i));
assert!(old_size < new_size);
let old = Layout::from_size_align(old_size, ALIGN).unwrap();
ascend[2 * i + 1] = reallocate(p1, old.clone(), new.clone());
sanity_check(&*ascend);
ascend[2 * i] = reallocate(p0, old.clone(), new.clone());
sanity_check(&*ascend);
}
}
// Test 4: turn the square back into a triangle, bottom to top.
unsafe fn test_4(ascend: &mut [*mut u8]) {
let old_size = idx_to_size(COUNT - 1);
let old = Layout::from_size_align(old_size, ALIGN).unwrap();
for i in (0..COUNT / 2).rev() {
let (p0, p1, new_size) = (ascend[2 * i], ascend[2 * i + 1], idx_to_size(i));
assert!(new_size < old_size);
let new = Layout::from_size_align(new_size, ALIGN).unwrap();
ascend[2 * i + 1] = reallocate(p1, old.clone(), new.clone());
sanity_check(&*ascend);
ascend[2 * i] = reallocate(p0, old.clone(), new.clone());
sanity_check(&*ascend);
}
}
}
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