[libcxx-commits] [libcxx] [libc++][hardening] Finish documenting hardening. (PR #92021)

[Louis Dionne via libcxx-commits]

================
@@ -72,17 +75,340 @@ to control the level by passing **one** of the following options to the compiler
 Notes for vendors
 -----------------
 
-Vendors can set the default hardening mode by providing ``LIBCXX_HARDENING_MODE``
-as a configuration option, with the possible values of ``none``, ``fast``,
-``extensive`` and ``debug``. The default value is ``none`` which doesn't enable
-any hardening checks (this mode is sometimes called the ``unchecked`` mode).
+Vendors can set the default hardening mode by providing
+``LIBCXX_HARDENING_MODE`` as a configuration option, with the possible values of
+``none``, ``fast``, ``extensive`` and ``debug``. The default value is ``none``
+which doesn't enable any hardening checks (this mode is sometimes called the
+``unchecked`` mode).
 
 This option controls both the hardening mode that the precompiled library is
 built with and the default hardening mode that users will build with. If set to
 ``none``, the precompiled library will not contain any assertions, and user code
 will default to building without assertions.
 
-Iterator bounds checking
-------------------------
+Vendors can also override the termination handler by :ref:`providing a custom
+header <override-assertion-handler>`.
 
-TODO(hardening)
+Assertion categories
+====================
+
+Inside the library, individual assertions are grouped into different
+*categories*. Each hardening mode enables a different set of assertion
+categories; categories provide an additional layer of abstraction that makes it
+easier to reason about the high-level semantics of a hardening mode.
----------------
ldionne wrote:

Perhaps add:
> Users are not intended to interact with these categories directly -- the categories are considered internal to the library and subject to change.

https://github.com/llvm/llvm-project/pull/92021