Move test_shrink_to_unwind to its own file. · model-checking/verify-rust-std@d0c07aa (original) (raw)
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#![feature(alloc_error_hook)]
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use crate::alloc::{AllocError, Layout};
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use core::{iter::TrustedLen, ptr::NonNull};
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use std::{
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alloc::{set_alloc_error_hook, take_alloc_error_hook, System},
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panic::{catch_unwind, AssertUnwindSafe},
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};
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use core::iter::TrustedLen;
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`use super::*;
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`@@ -797,52 +790,6 @@ fn test_shrink_to() {
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`}
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#[test]
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fn test_shrink_to_unwind() {
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// This tests that shrink_to leaves the deque in a consistent state when
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// the call to RawVec::shrink_to_fit unwinds. The code is adapted from #123369
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// but changed to hopefully not have any UB even if the test fails.
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struct BadAlloc;
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unsafe impl Allocator for BadAlloc {
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fn allocate(&self, l: Layout) -> Result<NonNull<[u8]>, AllocError> {
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// We allocate zeroed here so that the whole buffer of the deque
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// is always initialized. That way, even if the deque is left in
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// an inconsistent state, no uninitialized memory should be accessed.
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System.allocate_zeroed(l)
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}
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unsafe fn deallocate(&self, ptr: NonNull, layout: Layout) {
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unsafe { System.deallocate(ptr, layout) }
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}
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unsafe fn shrink(
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&self,
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_ptr: NonNull,
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_old_layout: Layout,
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_new_layout: Layout,
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) -> Result<NonNull<[u8]>, AllocError> {
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Err(AllocError)
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}
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}
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// preserve the old error hook just in case.
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let old_error_hook = take_alloc_error_hook();
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set_alloc_error_hook(|_| panic!("alloc error"));
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let mut v = VecDeque::with_capacity_in(15, BadAlloc);
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v.push_back(1);
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v.push_front(2);
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// This should unwind because it calls BadAlloc::shrink and then handle_alloc_error which unwinds.
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assert!(catch_unwind(AssertUnwindSafe(|| v.shrink_to_fit())).is_err());
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// This should only pass if the deque is left in a consistent state.
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assert_eq!(v, [2, 1]);
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// restore the old error hook.
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set_alloc_error_hook(old_error_hook);
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}
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`#[test]
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`fn test_shrink_to_fit() {
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`// This test checks that every single combination of head and tail position,
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