Commit Graph

38 Commits

Author SHA1 Message Date
Mark de Wever b968c3452b [libc++] Removes _LIBCPP_AVAILABILITY_TO_CHARS.
After moving the std::to_chars base 10 implementation from the dylib to
the header the integral overloads of std::to_chars are available on all
platforms.

Remove the _LIBCPP_AVAILABILITY_TO_CHARS availability macro and update
the tests.

Depends on D125704

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D125745
2022-06-07 18:59:19 +02:00
Mark de Wever dea7a8e616 [libc++] Don't use static constexpr in headers.
This was noticed in the review of D125704. In that commit only the new
table has been adapted. This adapts the existing tables.

Note since libc++'s charconv is backported to C++11 it's not possible to
use inline constexpr variables. The were introduced in C++17.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D126887
2022-06-07 18:47:44 +02:00
Mark de Wever a15ae4139c [libc++] Make to_chars base 10 header only.
The functions to_chars and from_chars should offer 128-bit support. This
is the first step to implement 128-bit version of to_chars. Before
implementing 128-bit support the current code will be polished.

This moves the code from the dylib to the header in prepartion of

P2291 "Add Constexpr Modifiers to Functions to_chars and from_chars for
Integral Types in <charconv> Header"

Note some more cleanups will be done in follow-up commits
- Remove the _LIBCPP_AVAILABILITY_TO_CHARS from to_chars. With all code
  in the header the availablilty macro is no longer needed. This
  requires enabling the unit tests for additional platforms.
- The code in the dylib can switch to using the header implementation.
  This allows removing the code duplicated in the header and the dylib.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D125704
2022-06-02 08:00:31 +02:00
Mark de Wever 6c11aebd30 [libc++] Improve std::to_chars for base != 10.
This improves the speed of `to_chars` for bases 2, 8, and 16.
These bases are common and used in `<format>`. This change
uses a lookup table, like done in base 10 and causes an increase
in code size. The change has a small overhead for the other bases.

```
Benchmark                             Time             CPU      Time Old      Time New       CPU Old       CPU New
------------------------------------------------------------------------------------------------------------------
BM_to_chars_good/2                 -0.9476         -0.9476           252            13           252            13
BM_to_chars_good/3                 +0.0018         +0.0018           145           145           145           145
BM_to_chars_good/4                 +0.0108         +0.0108           104           105           104           105
BM_to_chars_good/5                 +0.0159         +0.0160            89            91            89            91
BM_to_chars_good/6                 +0.0162         +0.0162            80            81            80            81
BM_to_chars_good/7                 +0.0117         +0.0117            72            73            72            73
BM_to_chars_good/8                 -0.8643         -0.8643            64             9            64             9
BM_to_chars_good/9                 +0.0095         +0.0095            60            60            60            60
BM_to_chars_good/10                +0.0540         +0.0540             6             6             6             6
BM_to_chars_good/11                +0.0299         +0.0299            55            57            55            57
BM_to_chars_good/12                +0.0060         +0.0060            48            49            49            49
BM_to_chars_good/13                +0.0102         +0.0102            48            48            48            48
BM_to_chars_good/14                +0.0184         +0.0185            47            48            47            48
BM_to_chars_good/15                +0.0269         +0.0269            44            45            44            45
BM_to_chars_good/16                -0.8207         -0.8207            37             7            37             7
BM_to_chars_good/17                +0.0241         +0.0241            37            38            37            38
BM_to_chars_good/18                +0.0221         +0.0221            37            38            37            38
BM_to_chars_good/19                +0.0222         +0.0223            37            38            37            38
BM_to_chars_good/20                +0.0317         +0.0317            38            39            38            39
BM_to_chars_good/21                +0.0342         +0.0341            38            39            38            39
BM_to_chars_good/22                +0.0336         +0.0336            36            38            36            38
BM_to_chars_good/23                +0.0222         +0.0222            34            35            34            35
BM_to_chars_good/24                +0.0185         +0.0185            31            32            31            32
BM_to_chars_good/25                +0.0157         +0.0157            32            32            32            32
BM_to_chars_good/26                +0.0181         +0.0181            32            32            32            32
BM_to_chars_good/27                +0.0153         +0.0153            32            32            32            32
BM_to_chars_good/28                +0.0179         +0.0179            32            32            32            32
BM_to_chars_good/29                +0.0189         +0.0189            32            33            32            33
BM_to_chars_good/30                +0.0212         +0.0212            32            33            32            33
BM_to_chars_good/31                +0.0221         +0.0221            32            33            32            33
BM_to_chars_good/32                +0.0292         +0.0292            32            33            32            33
BM_to_chars_good/33                +0.0319         +0.0319            32            33            32            33
BM_to_chars_good/34                +0.0411         +0.0410            33            34            33            34
BM_to_chars_good/35                +0.0515         +0.0515            33            34            33            34
BM_to_chars_good/36                +0.0502         +0.0502            32            34            32            34
BM_to_chars_bad/2                  -0.8752         -0.8752            40             5            40             5
BM_to_chars_bad/3                  +0.1952         +0.1952            21            26            21            26
BM_to_chars_bad/4                  +0.3626         +0.3626            16            22            16            22
BM_to_chars_bad/5                  +0.2267         +0.2268            17            21            17            21
BM_to_chars_bad/6                  +0.3560         +0.3559            14            19            14            19
BM_to_chars_bad/7                  +0.4599         +0.4600            12            18            12            18
BM_to_chars_bad/8                  -0.5074         -0.5074            11             5            11             5
BM_to_chars_bad/9                  +0.4814         +0.4814            10            15            10            15
BM_to_chars_bad/10                 +0.7761         +0.7761             2             4             2             4
BM_to_chars_bad/11                 +0.3948         +0.3948            12            16            12            16
BM_to_chars_bad/12                 +0.3203         +0.3203            10            13            10            13
BM_to_chars_bad/13                 +0.3067         +0.3067            11            14            11            14
BM_to_chars_bad/14                 +0.2235         +0.2235            12            14            12            14
BM_to_chars_bad/15                 +0.2675         +0.2675            11            14            11            14
BM_to_chars_bad/16                 -0.1801         -0.1801             7             5             7             5
BM_to_chars_bad/17                 +0.5651         +0.5651             7            11             7            11
BM_to_chars_bad/18                 +0.5407         +0.5406             7            11             7            11
BM_to_chars_bad/19                 +0.5593         +0.5593             8            12             8            12
BM_to_chars_bad/20                 +0.5823         +0.5823             8            13             8            13
BM_to_chars_bad/21                 +0.6032         +0.6032             9            15             9            15
BM_to_chars_bad/22                 +0.6407         +0.6408             9            14             9            14
BM_to_chars_bad/23                 +0.6292         +0.6292             7            12             7            12
BM_to_chars_bad/24                 +0.5784         +0.5784             6            10             6            10
BM_to_chars_bad/25                 +0.5784         +0.5784             6            10             6            10
BM_to_chars_bad/26                 +0.5713         +0.5713             7            10             7            10
BM_to_chars_bad/27                 +0.5969         +0.5969             7            11             7            11
BM_to_chars_bad/28                 +0.6131         +0.6131             7            11             7            11
BM_to_chars_bad/29                 +0.6937         +0.6937             7            11             7            11
BM_to_chars_bad/30                 +0.7655         +0.7656             7            12             7            12
BM_to_chars_bad/31                 +0.8939         +0.8939             6            12             6            12
BM_to_chars_bad/32                 +1.0157         +1.0157             6            13             6            13
BM_to_chars_bad/33                 +1.0279         +1.0279             7            14             7            14
BM_to_chars_bad/34                 +1.0388         +1.0388             7            14             7            14
BM_to_chars_bad/35                 +1.0990         +1.0990             7            15             7            15
BM_to_chars_bad/36                 +1.1503         +1.1503             7            15             7            15
```

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D97705
2022-05-14 13:01:35 +02:00
Louis Dionne 385cc25a53 [libc++] Ensure that all public C++ headers include <__assert>
This patch changes the requirement for getting the declaration of the
assertion handler from including <__assert> to including any public
C++ header of the library. Note that C compatibility headers are
excluded because we don't implement all the C headers ourselves --
some of them are taken straight from the C library, like assert.h.

It also adds a generated test to check it. Furthermore, this new
generated test is designed in a way that will make it possible to
replace almost all the existing test-generation scripts with this
system in upcoming patches.

Differential Revision: https://reviews.llvm.org/D122506
2022-03-30 15:05:31 -04:00
Louis Dionne e39095a32e [libc++] Define _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER whenever we enable warnings in the test suite
This should make CI consistent on all the compilers we support. Most of
this patch is working around various warnings emitted by GCC in our code
base, which are now being shown when we compile the tests.

After this patch, the whole test suite should be warning free on all
compilers we support and test, except for a few warnings on GCC that
we silence explicitly until we figure out the proper fix for them.

Differential Revision: https://reviews.llvm.org/D120684
2022-03-15 17:17:54 -04:00
Mark de Wever 3925f98de4 [libc++][NFC] Cleanups in <charconv>.
Based on review comments in D97705 applied some code cleanups in
<charconv>. The header now uses a more recent libc++ style.

Reviewed By: Quuxplusone, #libc, philnik

Differential Revision: https://reviews.llvm.org/D121223
2022-03-09 17:52:02 +01:00
Louis Dionne f87aa19be6 [libc++] Move everything related solely to _LIBCPP_ASSERT to its own file
This is the first step towards disentangling the debug mode and assertions
in libc++. This patch doesn't make any functional change: it simply moves
_LIBCPP_ASSERT-related stuff to its own file so as to make it clear that
libc++ assertions and the debug mode are different things. Future patches
will make it possible to enable assertions without enabling the debug
mode.

Differential Revision: https://reviews.llvm.org/D119769
2022-02-16 12:49:50 -05:00
Nikolas Klauser 2a8f9a5e95 [libc++] Implement P0627R6 (Function to mark unreachable code)
Reviewed By: ldionne, Quuxplusone, #libc

Spies: arichardson, mstorsjo, libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D119152
2022-02-14 20:52:51 +01:00
Arthur O'Dwyer fa6b9e4010 [libc++] Normalize all our '#pragma GCC system_header', and regression-test.
Now we'll notice if a header forgets to include this magic phrase.

Differential Revision: https://reviews.llvm.org/D118800
2022-02-04 12:27:19 -05:00
Mark de Wever abb5dd6e99 Microsoft's floating-point to_chars powered by Ryu and Ryu Printf
Microsoft would like to contribute its implementation of floating-point to_chars to libc++. This uses the impossibly fast Ryu and Ryu Printf algorithms invented by Ulf Adams at Google. Upstream repos: https://github.com/microsoft/STL and https://github.com/ulfjack/ryu .

Licensing notes: MSVC's STL is available under the Apache License v2.0 with LLVM Exception, intentionally chosen to match libc++. We've used Ryu under the Boost Software License.

This patch contains minor changes from Jorg Brown at Google, to adapt the code to libc++. He verified that it works in Google's Linux-based environment, but then I applied more changes on top of his, so any compiler errors are my fault. (I haven't tried to build and test libc++ yet.) Please tell me if we need to do anything else in order to follow https://llvm.org/docs/DeveloperPolicy.html#attribution-of-changes .

Notes:

* libc++'s integer charconv is unchanged (except for a small refactoring). MSVC's integer charconv hasn't been tuned for performance yet, so you're not missing anything.
* Floating-point from_chars isn't part of this patch because Jorg found that MSVC's implementation (derived from our CRT's strtod) was slower than Abseil's. If you're unable to use Abseil or another implementation due to licensing or technical considerations, Microsoft would be delighted if you used MSVC's from_chars (and you can just take it, or ask us to provide a patch like this). Ulf is also working on a novel algorithm for from_chars.
* This assumes that float is IEEE 32-bit, double is IEEE 64-bit, and long double is also IEEE 64-bit.
* I have added MSVC's charconv tests (the whole thing: integer/floating from_chars/to_chars), but haven't adapted them to libcxx's harness at all. (These tests will be available in the microsoft/STL repo soon.)
* Jorg added int128 codepaths. These were originally present in upstream Ryu, and I removed them from microsoft/STL purely for performance reasons (MSVC doesn't support int128; Clang on Windows does, but I found that x64 intrinsics were slightly faster).
* The implementation is split into 3 headers. In MSVC's STL, charconv contains only Microsoft-written code. xcharconv_ryu.h contains code derived from Ryu (with significant modifications and additions). xcharconv_ryu_tables.h contains Ryu's large lookup tables (they were sufficiently large to make editing inconvenient, hence the separate file). The xmeow.h convention is MSVC's for internal headers; you may wish to rename them.
* You should consider separately compiling the lookup tables (see https://github.com/microsoft/STL/issues/172 ) for compiler throughput and reduced object file size.
* See https://github.com/StephanTLavavej/llvm-project/commits/charconv for fine-grained history. (If necessary, I can perform some rebase surgery to show you what Jorg changed relative to the microsoft/STL repo; currently that's all fused into the first commit.)

Differential Revision: https://reviews.llvm.org/D70631
2021-12-12 16:34:50 +01:00
Petr Hosek ae53d02f55 Revert "Microsoft's floating-point to_chars powered by Ryu and Ryu Printf"
This reverts commit a8025e06fc since
it triggers PR52584 with debug info enabled.
2021-12-07 00:10:14 -08:00
Mark de Wever a8025e06fc Microsoft's floating-point to_chars powered by Ryu and Ryu Printf
Microsoft would like to contribute its implementation of floating-point to_chars to libc++. This uses the impossibly fast Ryu and Ryu Printf algorithms invented by Ulf Adams at Google. Upstream repos: https://github.com/microsoft/STL and https://github.com/ulfjack/ryu .

Licensing notes: MSVC's STL is available under the Apache License v2.0 with LLVM Exception, intentionally chosen to match libc++. We've used Ryu under the Boost Software License.

This patch contains minor changes from Jorg Brown at Google, to adapt the code to libc++. He verified that it works in Google's Linux-based environment, but then I applied more changes on top of his, so any compiler errors are my fault. (I haven't tried to build and test libc++ yet.) Please tell me if we need to do anything else in order to follow https://llvm.org/docs/DeveloperPolicy.html#attribution-of-changes .

Notes:

* libc++'s integer charconv is unchanged (except for a small refactoring). MSVC's integer charconv hasn't been tuned for performance yet, so you're not missing anything.
* Floating-point from_chars isn't part of this patch because Jorg found that MSVC's implementation (derived from our CRT's strtod) was slower than Abseil's. If you're unable to use Abseil or another implementation due to licensing or technical considerations, Microsoft would be delighted if you used MSVC's from_chars (and you can just take it, or ask us to provide a patch like this). Ulf is also working on a novel algorithm for from_chars.
* This assumes that float is IEEE 32-bit, double is IEEE 64-bit, and long double is also IEEE 64-bit.
* I have added MSVC's charconv tests (the whole thing: integer/floating from_chars/to_chars), but haven't adapted them to libcxx's harness at all. (These tests will be available in the microsoft/STL repo soon.)
* Jorg added int128 codepaths. These were originally present in upstream Ryu, and I removed them from microsoft/STL purely for performance reasons (MSVC doesn't support int128; Clang on Windows does, but I found that x64 intrinsics were slightly faster).
* The implementation is split into 3 headers. In MSVC's STL, charconv contains only Microsoft-written code. xcharconv_ryu.h contains code derived from Ryu (with significant modifications and additions). xcharconv_ryu_tables.h contains Ryu's large lookup tables (they were sufficiently large to make editing inconvenient, hence the separate file). The xmeow.h convention is MSVC's for internal headers; you may wish to rename them.
* You should consider separately compiling the lookup tables (see https://github.com/microsoft/STL/issues/172 ) for compiler throughput and reduced object file size.
* See https://github.com/StephanTLavavej/llvm-project/commits/charconv for fine-grained history. (If necessary, I can perform some rebase surgery to show you what Jorg changed relative to the microsoft/STL repo; currently that's all fused into the first commit.)

Differential Revision: https://reviews.llvm.org/D70631
2021-12-05 13:25:33 +01:00
Nikolas Klauser d2b0df35af [libc++][NFC] Update namespace comments in include/
update the namspace comments in include/

Reviewed By: ldionne, #libc

Spies: smeenai, libcxx-commits

Differential Revision: https://reviews.llvm.org/D114947
2021-12-02 21:06:59 +01:00
Mark de Wever 3624c4d845 [libc++] Adds (to|from)_chars_result operator==.
Implements part of P1614 The Mothership has Landed.

Reviewed By: #libc, Quuxplusone, Mordante

Differential Revision: https://reviews.llvm.org/D112366
2021-11-19 16:29:33 +01:00
Louis Dionne eb8650a757 [runtimes][NFC] Remove filenames at the top of the license notice
We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste stuff.
This cleans up all the existing files so as to stop the spreading
as people copy-paste headers around.
2021-11-17 16:30:52 -05:00
Mark de Wever bfc253c000 [libc++][nfc] Improve standard conformance.
The return type of the deleted functions doesn't match the synopsis in
the standard.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D114000
2021-11-16 17:30:35 +01:00
Konstantin Varlamov a59c1a2138 [libc++] LWG3266: delete the to_chars(bool) overload.
This PR only updates the synopsis in `<charconv>` -- the current
implementation already [deletes](e9e6266c70/libcxx/include/charconv (L108))
the overload and has a [test](https://github.com/llvm/llvm-project/blob/main/libcxx/test/std/utilities/charconv/charconv.to.chars/integral.bool.fail.cpp)
for it (and this has been the case from the first [commit](https://reviews.llvm.org/D41458)
where `<charconv>` was added).

Reviewed By: #libc, Mordante

Differential Revision: https://reviews.llvm.org/D111845
2021-10-15 17:52:58 +02:00
Mark de Wever e983a659e5 [libc++][NFC] split <charconv>.
This move the helper types `chars_format`, `to_chars_result` and
`from_chars_result` to a separate header. The first two are needed for
D70631 the third for consistency.

The header `__charconv/ryu.h` uses these types and it can't depend on the
types in `<charconv>` in a modular build. Moving them to the ryu header
would be an odd place and doesn't work since the header is included in the
middle of `<charconv>`.

Reviewed By: #libc, ldionne, Quuxplusone

Differential Revision: https://reviews.llvm.org/D108927
2021-08-31 18:45:19 +02:00
Mark de Wever 96ed451f8d [libc++][NFC] Remove MSVC specific code.
Switching `__builtin_clzll`  to `__libcpp_clz` should work on all
platforms and no longer require MSVC specific code.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D107709
2021-08-09 18:13:49 +02:00
Louis Dionne 2e4755ff60 [libc++] Fix a few warnings in system headers with GCC
This isn't fixing all of them, but at least it's making some progress.

Differential Revision: https://reviews.llvm.org/D106283
2021-07-27 20:09:01 -04:00
Arthur O'Dwyer bfbd73f87d [libc++] Alphabetize and include-what-you-use. NFCI.
Differential Revision: https://reviews.llvm.org/D102781
2021-05-29 19:54:48 -04:00
Mark de Wever c273f5ef7d [libc++][nfc] remove duplicated __to_unsigned.
Both `<type_traits>` and `<charconv>` implemented this function with
different names and a slightly different behavior. This removes the
version in `<charconv>` and improves the version in `<typetraits>`.

- The code can be used again in C++11.
-  The original claimed C++14 support, but `[[nodiscard]]` is not
   available in  C++14.
- Adds `_LIBCPP_INLINE_VISIBILITY`.

Reviewed By: zoecarver, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D102332
2021-05-12 21:09:49 +02:00
Mark de Wever 9393060f90 [libc++] Fixes std::to_chars for bases != 10.
While working on D70631, Microsoft's unit tests discovered an issue.
Our `std::to_chars` implementation for bases != 10 uses the range
`[first,last)` as temporary buffer. This violates the contract for
to_chars:
[charconv.to.chars]/1 http://eel.is/c++draft/charconv#to.chars-1
`to_chars_result to_chars(char* first, char* last, see below value, int base = 10);`
"If the member ec of the return value is such that the value is equal to
the value of a value-initialized errc, the conversion was successful and
the member ptr is the one-past-the-end pointer of the characters
written."

Our implementation modifies the range `[member ptr, last)`, which causes
Microsoft's test to fail. Their test verifies the buffer
`[member ptr, last)` is unchanged. (The test is only done when the
conversion is successful.)

While looking at the code I noticed the performance for bases != 10 also
is suboptimal. This is tracked in D97705.

This patch fixes the issue and adds a benchmark. This benchmark will be
used as baseline for D97705.

Reviewed By: #libc, Quuxplusone, zoecarver

Differential Revision: https://reviews.llvm.org/D100722
2021-04-29 19:56:28 +02:00
Mark de Wever a354fd56c5 [libc++] Adds __utility/to_underlying.h.
During the review of D97115 it was mentioned adding the `<utility>`
header for `__to_underlying` was a bit unfortunate. Nowadays we tend to
implement smaller headers, so a good reason to move `std::to_underlying`
to its own header and adjust `<charconv>` to use the new header.

Differential Revision: https://reviews.llvm.org/D101233
2021-04-25 13:27:19 +02:00
Louis Dionne 4cd6ca102a [libc++] NFC: Normalize `#endif //` comment indentation 2021-04-20 12:03:32 -04:00
Mark de Wever ac08e2bb98 [libc++] Make chars_format a bitmask type.
Some of Microsoft's unit tests in D70631 fail because libc++'s
implementation of std::chars_format isn't a proper bitmask type. Adding
the required functions to make std::chars_format a proper bitmask type.

Implements parts of P0067: Elementary string conversions

Differential Revision: https://reviews.llvm.org/D97115
2021-04-14 18:17:38 +02:00
Arthur O'Dwyer b12ea06521 [libc++] Include C++ headers, not C headers, in <charconv>.
This matches how libc++ does it in all other C++ headers
(that is, headers not ending in ".h").
We need to include <cstring> if we want to use `_VSTD::memmove`
instead of unqualified ADL `memmove`. Even though ADL doesn't
physically matter in <charconv>'s specific case, I'm trying
to migrate libc++ to using `_VSTD::memmove` for all cases
(because some of them do matter, and this way it's easier to
grep for outliers).

Differential Revision: https://reviews.llvm.org/D92875
2020-12-10 22:03:12 -05:00
Arthur O'Dwyer 03ee461276 [libc++] Consistently unparenthesize `numeric_limits<T>::max`. NFCI.
I think people were sometimes parenthesizing `(foo::max)()` out of
misplaced concern that an unparenthesized `foo::max()` would trip up
Windows' `max(a,b)` macro. However, this is not the case: `max(a,b)`
should be tripped up only by an unparenthesized call to `foo::max(a,b)`,
and in fact we already do `_VSTD::max(a,b)` all over the place anyway
without any guards.

However, in order to do it without guards, we must also
wrap the header in _LIBCPP_PUSH_MACROS, which <span> was not.

Differential Revision: https://reviews.llvm.org/D92240
2020-11-27 17:27:36 -05:00
Louis Dionne 2eadbc8614 [libc++] Rework the whole availability markup implementation
Currently, vendor-specific availability markup is enabled by default.
This means that even when building against trunk libc++, the headers
will by default prevent you from using some features that were not
released in the dylib on your target platform. This is a source of
frustration since people building libc++ from sources are usually not
trying to use some vendor's released dylib.

For that reason, I've been thinking for a long time that availability
annotations should be off by default, which is the primary change that
this commit enables.

In addition, it reworks the implementation to make it easier for new
vendors to add availability annotations for their platform, and it
refreshes the documentation to reflect the current state of the codebase.

Finally, a CMake configuration option is added to control whether
availability annotations should be turned on for the flavor of libc++
being created. The intent is for vendors like Apple to turn it on, and
for the upstream libc++ to leave it off (the default).

Differential Revision: https://reviews.llvm.org/D90843
2020-11-05 12:28:52 -05:00
Louis Dionne 485b9083fe [libc++] Mark __u64toa and __u32toa as noexcept
The two functions don't throw, and the generated code is better when
we explicitly tell the compiler that the functions are noexcept. This
isn't an ABI break because the signatures of the functions stay the
same with or without noexcept.

Fixes https://llvm.org/PR46016

Differential Revision: https://reviews.llvm.org/D80379
2020-05-22 16:11:44 -04:00
Louis Dionne 8b60ba73af [libc++] Add availability markup for std::to_chars on Apple platforms
Summary:
Otherwise, one gets link errors when trying to back-deploy to older platforms.

rdar://problem/57854364

Reviewers: lichray, EricWF

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D74626
2020-02-17 09:32:46 -05:00
Thomas Anderson 2ce370c957 [libc++] Fix build with gcc 4.8
gcc 4.8.4 (but not 5.4.0 or 7.3.0) has trouble initializing errc with {}, giving
the error in [1]. This CL switches to explicitly using errc(0), which gcc 4.8
accepts.

[1] https://bugs.chromium.org/p/chromium/issues/detail?id=973723

Differential Revision: https://reviews.llvm.org/D63296

llvm-svn: 363333
2019-06-13 22:27:24 +00:00
Marshall Clow 769c2459d5 Make to_chars/from_chars work back to C++11. This means that we can use them to implement to_string as well. Reviewed as https://reviews.llvm.org/D59598.
llvm-svn: 356585
2019-03-20 18:13:23 +00:00
Chandler Carruth 57b08b0944 Update more file headers across all of the LLVM projects in the monorepo
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351648
2019-01-19 10:56:40 +00:00
Marshall Clow 27e9fdb2ff Run the min/max tests agaist the header <charconv>. Fix that header so it passes. NFC.
llvm-svn: 345352
2018-10-26 01:00:56 +00:00
Louis Dionne 9b3222f613 [libc++] Make sure we can build libc++ with -fvisibility=hidden
Summary:
When building with -fvisibility=hidden, some symbols do not get exported from
libc++.dylib. This means that some entities are not explicitly given default
visibility in the source code, and that we rely on the fact -fvisibility=default
is the default. This commit explicitly gives default visibility to those
symbols to avoid being dependent on the command line flags used.

The commit also remove symbols from the dylib -- those symbols do not
actually need to be exported from the dylib and this should not be an
ABI break.

Finally, in the future, we may want to mark the whole std:: namespace as
having hidden visibility (to switch from opt-out to opt-in), in which
case the changes done in this commit will be required.

Reviewers: EricWF

Subscribers: mgorny, christof, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D52662

llvm-svn: 345260
2018-10-25 12:13:43 +00:00
Zhihao Yuan d27489645b [libc++][C++17] Elementary string conversions for integral types
Summary:
Major QoI considerations:

- The facility is backported to C++14, same as libstdc++.
- Efforts have been made to minimize the header dependencies.
- The design is friendly to the uses of MSVC intrinsics (`__emulu`, `_umul128`, `_BitScanForward`, `_BitScanForward64`) but not implemented; future contributions are welcome.

Thanks to Milo Yip for contributing the implementation of `__u64toa` and `__u32toa`.

References:
 https://wg21.link/p0067r5
 https://wg21.link/p0682r1

Reviewers: mclow.lists, EricWF

Reviewed By: mclow.lists

Subscribers: ldionne, Quuxplusone, christof, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D41458

llvm-svn: 338479
2018-08-01 02:38:30 +00:00