Create a new `__capacity_aware_iterator` iterator type which wraps an
existing iterator, takes its container as a template parameter, and
encodes the maximum amount of elements the container can hold. The main
objective is to prevent iterator mixups between different containers
(e.g. `vector`).
This patch moves all macros which expand to attributes into a detail
header, including the relatively complex visibility and ABI-hiding
attributes. This also adds sections for attributes that are important to
not be ignored. At the bottom there is a catch-all section for
attributes which can safely be ignored and are only important for the
quality of implementation.
The existence of <float.h> in libc++ leads to difficulties with modules,
especially when it comes to supporting the various __need macros
supported by the Clang builtin headers.
Fortunately, libc++'s <float.h> only defines FLT_EVAL_METHOD and
DECIMAL_DIG, which are already defined by the Clang builtin headers in
C++11 mode. Hence, removing the header entirely should have no impact,
apart from not defining FLT_EVAL_METHOD and DECIMAL_DIG in C++03 mode.
However, that is arguably something that libc++ shouldn't be doing: if
the underlying C library doesn't want to provide these definitions, then
libc++ shouldn't force it to.
#175913 removed that `__builtin_assume_dereferenceable(ptr, 0)` implies
`ptr != nullptr`, which should allow us to use the builtin with LLVM 23.
This reverts commit 776c09c212e945fdceeae240b42c38df3dd34727.
`__builtin_assume_dereferenceable` currently implies that the pointer
given to it is non-null, even if the size is zero. This causes
miscompilations, since we consider [nullptr, nullptr) to be a valid
range.
Reverts llvm/llvm-project#167697
It makes sense to decouple traits from the things they describe, since
that's the purpose of traits. Furthermore, this will make it possible to
reuse these traits from other places in the library (e.g. <semaphore>)
outside of the synchronization library.
Pre-C++20 support is removed as a drive-by since the synchronization
library does not support pre-C++20 anymore. This makes it possible to
simplify a few constructs by using concepts.
Requested in https://github.com/llvm/llvm-project/pull/172214#discussion_r2635968291
This implements all of [P2404R3](https://wg21.link/p2404r3)'s concept
changes.
---------
Co-authored-by: A. Jiang <de34@live.cn>
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
## Introduction
This patch implements `ranges::elements_of` from
[P2502R2](https://wg21.link/P2502R2). Specializations of `elements_of`
encapsulate a range and act as a tag in overload sets to disambiguate
when a range should be treated as a sequence rather than a single value.
```cpp
template <bool YieldElements>
std::generator<std::any> f(std::ranges::input_range auto &&r) {
if constexpr (YieldElements) {
co_yield std::ranges::elements_of(r);
} else {
co_yield r;
}
}
```
## Reference
- [P2502R2: `std::generator`: Synchronous Coroutine Generator for
Ranges](https://wg21.link/P2502R2)
- [[range.elementsof]](https://eel.is/c++draft/range.elementsof)
Partially addresses #105226
---------
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
Co-authored-by: A. Jiang <de34@live.cn>
`[[nodiscard]]` should be applied to functions where discarding the
return value is most likely a correctness issue.
- https://libcxx.llvm.org/CodingGuidelines.html
1. `hash<shared_ptr>`, `hash<unique_ptr>`, `std::integer_sequence<>`
etc.
2. Also implements fixes to
https://github.com/llvm/llvm-project/issues/169634 on the go (issues
discovered during current implementation)
---------
Co-authored-by: A. Jiang <de34@live.cn>
Co-authored-by: Hristo Hristov <zingam@outlook.com>
Tested on Newlib v4.5.0. The newlib.h was mostly copied from linux.h
within the same directory.
Newlib locale support was initially added in http://llvm.org/D5385,
but removed in #113721 , because of revision http://llvm.org/D49927.
```
---------------------------------------------------
Benchmark old new
---------------------------------------------------
BM_num_get<bool> 86.5 ns 32.3 ns
BM_num_get<long> 82.1 ns 30.3 ns
BM_num_get<long long> 85.2 ns 33.4 ns
BM_num_get<unsigned short> 85.3 ns 31.2 ns
BM_num_get<unsigned int> 84.2 ns 31.1 ns
BM_num_get<unsigned long> 83.6 ns 31.9 ns
BM_num_get<unsigned long long> 87.7 ns 31.5 ns
BM_num_get<float> 116 ns 114 ns
BM_num_get<double> 114 ns 114 ns
BM_num_get<long double> 113 ns 114 ns
BM_num_get<void*> 151 ns 144 ns
```
This patch applies multiple optimizations:
- Stages two and three of do_get are merged and a custom integer parser
has been implemented
This avoids allocations, removes the need for strto{,u}ll and avoids
__stage2_int_loop (avoiding extra writes to memory)
- std::find has been replaced with __atoms_offset, which uses vector
instructions to look for a character
Fixes#158100Fixes#158102
This should improve the time it takes to run the test suite a bit. Right
now there are only a handful of headers in the modulemap because we're
missing a lot of includes in the tests. New headers should be added
there from the start, and we should fill up the modulemap over time
until it contains all the test support headers.
`<stdbool.h>` is provided by the compiler and both Clang and GCC provide
C++-aware versions of these headers, making our own wrapper header
entirely unnecessary.
The Trivial Relocation feature has been removed from the C++26 working
draft. Based on discussions in Kona, it is unlikely that the
"replaceable" type concept will come back in the C++29 time frame.
Since we don't have a use for the type trait in the library at the
moment, remove the code associated to it. If we end up needing something
like it in the future, we can always add it back.
<https://wg21.link/P2641R4>
Implements the C++26 function in `<type_traits>` [meta.const.eval] (and
the corresponding feature test macro `__cpp_lib_is_within_lifetime`)
```c++
template<class T>
consteval bool is_within_lifetime(const T*) noexcept;
```
This is done with the `__builtin_is_within_lifetime` builtin added to
Clang 20 by #91895 / 2a07509c8d3c8b5b2c88e4f73dde0071bf506870. This is
not (currently) available with GCC.
This implementation has provisions for LWG4138
<https://cplusplus.github.io/LWG/issue4138> where it is ill-formed to
instantiate `is_within_lifetime<T>` with a function type `T`.
Closes#105381
Co-authored-by: Mital Ashok <mital@mitalashok.co.uk>
To my knowledge, NetBSD is mostly like other BSDs, but doesn't have
`xlocale.h`. I think c664a7f may have inadvertently broken this.
With this change, I was able to run
[zig-bootstrap](https://github.com/ziglang/zig-bootstrap) to completion
for `x86_64-netbsd10.1-none`.
This patch adds additional overloads to `map::at` in case its known that
the argument is transparently comparable to the key type. This avoids
actually constructing the key type in some cases, potentially removing
allocations.
```
--------------------------------------------------------
Benchmark old new
--------------------------------------------------------
BM_map_find_string_literal 12.8 ns 2.68 ns
```
We've built up quite a few links directly to github within the code
base. We should instead use `llvm.org/PR<issue-number>` to link to bugs,
since that is resilient to the bug tracker changing in the future. This
is especially relevant for tests linking to bugs, since they will
probably be there for decades to come. A nice side effect is that these
links are significantly shorter than the GH links, making them much less
of an eyesore.
This patch also replaces a few links that linked to the old bugzilla
instance on llvm.org.
This essentially inlines `__make_tuple_types` and simplifies the support
code. This significantly simplifies the implementation, since
`__make_tuple_types` has multiple features, but the different places
that use it only make use of a subset of the features. Inlining it
separates concerns better and leads to less code in total.
The original PR has been reverted because of an LLDB test failure. This
patch now works around the test failure by simply allowing the new
symbols to show up in a stack trace.
This reverts commit 72c04bb882ad70230bce309c3013d9cc2c99e9a7.
Original commit message:
This patch replaces `__can_extract_key` with an overload set to try to
extract the key. This simplifies the code, since we don't need to have
separate overload sets for the unordered and associative containers. It
also allows extending the set of extraction cases more easily, since we
have a single place to define how the key is extracted.
This patch replaces `__can_extract_key` with an overload set to try to
extract the key. This simplifies the code, since we don't need to have
separate overload sets for the unordered and associative containers. It
also allows extending the set of extraction cases more easily, since we
have a single place to define how the key is extracted.
Removing the unnecessary friend declarations from `<__tree>` also
removes the need for forward declaration headers for `map` and `set`,
which this patch also removes.
The SFINAE isn't required, since the primary `tuple` class already does
the SFINAE checks. This removes a bit of code that was only used for
these constraints.
This also moves the `tuple_element` specialization for `tuple` to
`__fwd/tuple.h` to avoid a dependency on `__tuple/sfinae_helpers.h`
(which should be moved in a follow-up).
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 internal API is a lot more complicated than it actually needs to be.
This refactors the internal API to match the features and names of the
public one.
