Reverts llvm/llvm-project#148266
I'm reverting this temporarily, since the release branch is today and
this is ABI sensitive. Let's wait until after the branch so that we have
plenty time to discuss the patch.
Unlike `verbose_abort`, this function merely logs the error but does not
terminate execution. It is intended to make it possible to implement the
`observe` semantic for Hardening.
The `_LIBCPP_DISABLE_AVAILABILITY` macro was removed in afae1a5f32bb as an
intended no-op. It turns out that some projects are making use of that
macro to work around a Clang bug with availability annotations that
still exists: https://github.com/llvm/llvm-project/issues/134151.
Since that Clang bug still hasn't been fixed, I feel that we must sill
honor that unfortunate macro until we've figured out how to get rid of
it without breaking code.
We're currently adding `bad_function_call::what()` behind an ABI flag,
even though adding it is not an ABI break and can be handled through
availability.
When I introduced the various `_LIBCPP_INTRODUCED_IN_LLVM_XY_ATTRIBUTE`
macros in 182f5e9b2f03, I tried to correlate them to the right OS
versions, but it seems that I made a few mistakes. This wasn't caught in
the CI because we don't test back-deployment that far.
rdar://148405946
This has multiple benefits:
- There is a single instance of our hash function, reducing object file
size
- The hash implementation isn't instantiated in every TU anymore,
reducing compile times
- Behind an ABI configuration macro it would be possible to salt the
hash
Implements std::from_chars for float and double.
The implementation uses LLVM-libc to do the real parsing. Since this is
the first time libc++
uses LLVM-libc there is a bit of additional infrastructure code. The
patch is based on the
[RFC] Project Hand In Hand (LLVM-libc/libc++ code sharing)
https://discourse.llvm.org/t/rfc-project-hand-in-hand-llvm-libc-libc-code-sharing/77701
Currently, the library-internal feature test macros are only defined if
the feature is not available, and always have the prefix
`_LIBCPP_HAS_NO_`. This patch changes that, so that they are always
defined and have the prefix `_LIBCPP_HAS_` instead. This changes the
canonical use of these macros to `#if _LIBCPP_HAS_FEATURE`, which means
that using an undefined macro (e.g. due to a missing include) is
diagnosed now. While this is rather unlikely currently, a similar change
in `<__configuration/availability.h>` caught a few bugs. This also
improves readability, since it removes the double-negation of `#ifndef
_LIBCPP_HAS_NO_FEATURE`.
The current patch only touches the macros defined in `<__config>`. If
people are happy with this approach, I'll make a follow-up PR to also
change the macros defined in `<__config_site>`.
This patch removes many annotations that are not relevant anymore since
we don't support or test back-deploying to macOS < 10.13. It also cleans
up raw usage of target triples to identify versions of dylibs shipped on
prior versions of macOS, and uses the target-agnostic Lit features
instead. Finally, it reorders both the Lit backdeployment features and
the corresponding availability macros in the library in a way that makes
more sense, and reformulates the Lit backdeployment features in terms of
when a version of LLVM was introduced instead of encoding the system
versions on which it hasn't been introduced yet. Although one can be
derived from the other, encoding the negative form is extremely
error-prone.
Fixes#80901
We were not making any distinction between e.g. the "Apple-flavored"
libc++ built from trunk and the system-provided standard library on
Apple platforms. For example, any test that would be XFAILed on a
back-deployment target would unexpectedly pass when run on that
deployment target against the tip of trunk Apple-flavored libc++. In
reality, that test would be expected to pass because we're running
against the latest libc++, even if it is Apple-flavored.
To solve this issue, we introduce a new feature that describes whether
the Standard Library in use is the one provided by the system by
default, and that notion is different from the underlying standard
library flavor. We also refactor the existing Lit features to make a
distinction between availability markup and the library we're running
against at runtime, which otherwise limit the flexibility of what we can
express in the test suite. Finally, we refactor some of the
back-deployment versions that were incorrect (such as thinking that LLVM
10 was introduced in macOS 11, when in reality macOS 11 was synced with
LLVM 11).
Fixes#82107
In essence, this header has always been related to configuration of
the library but we didn't want to put it inside <__config> due to
complexity reasons. Now that we have sub-headers in <__config>, we
can move <__availability> to it and stop including it everywhere since
we already obtain the required macros via <__config>.
