When we implemented array cookie support for hardening std::unique_ptr,
the implementation was only done for the Itanium ABI. I did not
initially realize that ARM was using a different ABI for array cookies,
so unique_ptr should not have been hardened on ARM.
However, we were also incorrectly setting the ABI-detection macro: we
were pretending to be using a vanilla Itanium ABI when in reality the
(similar but different) ARM ABI was in use. As a result, unique_ptr was
using the wrong representation for array cookies on ARM, which
fortunately only mattered in the case of overaligned types.
This patch fixes that.
rdar://160852193
It turns out that we can never do bounds-checking for unique_ptrs with
custom deleters, except when converting from a unique_ptr with a default
deleter to one with a custom deleter.
If we had an API like `std::make_unique` that allowed passing a custom
deleter, we could at least get bounds checking when the unique_ptr is
created through those APIs, but for now that is not possible.
Fixes#110683
This allows catching OOB accesses inside `unique_ptr<T[]>` when the size
of the allocation is known. The size of the allocation can be known when
the unique_ptr has been created with make_unique & friends or when the
type necessitates an array cookie before the allocation.
This is a re-aplpication of 45a09d181 which had been reverted in
f11abac6 due to unrelated CI failures.
This reverts 3 commits:
45a09d1811d5d6597385ef02ecf2d4b7320c37c5
24bc3244d4e221f4e6740f45e2bf15a1441a3076
bc6bd3bc1e99c7ec9e22dff23b4f4373fa02cae3
The GitHub pre-merge CI has been broken since this PR went in. This
change reverts it to see if I can get the pre-merge CI working again.
This allows catching OOB accesses inside `unique_ptr<T[]>` when the size
of the allocation is known. The size of the allocation can be known when
the unique_ptr has been created with make_unique & friends or when the
type necessitates an array cookie before the allocation.
