12 Commits

Author SHA1 Message Date
Louis Dionne
348e74139a [libc++][NFC] Run clang-format on libcxx/include
This re-formats a few headers that had become out-of-sync with respect
to formatting since we ran clang-format on the whole codebase. There's
surprisingly few instances of it.
2024-08-30 12:09:36 -04:00
Mark de Wever
402eb2ef09 [libc++][format] Improves diagnostics.
Improves both the compile-time and run-time errors.
At compile-time it does a bit more work to get more specific errors.
This could be done at run-time too, but that has a performance penalty.
Since it's expected most use-cases use format* instead of vformat* the
compile-time errors are more common.

For example when using

  std::format_to("{:-c}", 42);

Before compile output would contain

  std::__throw_format_error("The format-spec should consume the input or end with a '}'");

Now it contains

  std::__throw_format_error("The format specifier does not allow the sign option");

Given a better indication the sign option is not allowed. Note the
output is still not user-friendly; C++ doesn't have good facilities to
generate nice messages from the library.

In general all messages have been reviewed and improved, using a more
consistent style and using less terms used in the standard. For example

  format-spec -> format specifier
  arg-id -> argument index

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D152624
2023-07-18 21:11:12 +02:00
Mark de Wever
eb70334114 [NFC][libc++][format] Generalizes bracket parsing.
Both the tuple formatter and range formatter parse a bracket. Instead of
implementing this twice do it in the generic parser. This is preparation
to improve the diagnostics in the format library.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D155264
2023-07-18 20:32:58 +02:00
Mark de Wever
285e1e2a00 [libc++][format] Removes unneeded includes.
I did a manual review after the post-review comments in D149543

Reviewed By: #libc, philnik, ldionne

Differential Revision: https://reviews.llvm.org/D154122
2023-07-08 12:39:33 +02:00
Mark de Wever
b51e8acd82 [NFC][libc++][format] Uses uniform member signatures.
The newer formatters for (tuple, vector<bool>::reference) specify the
formatter's parse and format member function. This signature is slightly
different from the signature for existing formatters. Adapt the existing
formatters to the new style.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D150034
2023-05-12 17:48:23 +02:00
Mark de Wever
9b43aedeb3 [libc++][format] Implements LWG3892.
This LWG issue is based on the discussion regarding

  P2733R3 Fix handling of empty specifiers in std::format

This paper was disussed and changed a few times in LEWG during the
Issaquah meeting. The paper was not voted in, instead LEWG asked for
a DR against C++26.

This LWG issue contains the direction voted by LEWG. This issue has not
been voted in yet. However it fixes some of the defencies on the
container based formatting. Without this fix the range-default-formatter
for strings looks bad when used in containers.

The changes of this issue match the intended changes of P27333.

type                      fmt     before     after (if changed)
---------------------------------------------------------------
char                      {}      a
char                      {:?}    'a'
array<char, 1>            {}      ['a']
array<char, 1>            {::}    [a]
array<char, 1>            {::c}   [a]
array<char, 1>            {::?}   ['a']
map<char, char>           {}      {a: a}     -> {'a': 'a'}
map<char, char>           {::}    {'a': 'a'}
set<char>                 {}      {'a'}
set<char>                 {::}    {a}
set<char>                 {::c}   {a}
set<char>                 {::?}   {'a'}
tuple<char>               {}      ('a')
stack<char>               {}      ['a']
stack<char>               {::}    [a]
stack<char>               {::c}   [a]
stack<char>               {::?}   ['a']
array<array<char, 1>, 1>  {}      [[a]]      -> {'a': 'a'}
array<array<char, 1>, 1>  {::}    [['a']]
array<array<char, 1>, 1>  {:::}   [[a]]
array<array<char, 1>, 1>  {:::c}  [[a]]
array<array<char, 1>, 1>  {:::?}  [['a']]
array<tuple<char>, 1>     {}      [(a)]      -> [('a')]
tuple<tuple<char>>        {}      ((a))      -> (('a'))
tuple<array<char, 1>>     {}      ([a])      -> (['a'])

Note the optimization text as mentioned in the tuple formatter can't be
done. The call to parse may affect the formatter so its state needs to
be preserved.

Reviewed By: ldionne, #libc, EricWF

Differential Revision: https://reviews.llvm.org/D145847
2023-04-08 14:12:04 +02:00
Louis Dionne
3d334df587 [libc++] Remove availability markup for std::format
std::format is currently experimental, so there is technically no
deployment target requirement for it (since the only symbols required
for it are in `libc++experimental.a`).

However, some parts of std::format depend indirectly on the floating
point std::to_chars implementation, which does have deployment target
requirements.

This patch removes all the availability format for std::format and
updates the XFAILs in the tests to properly explain why they fail
on old deployment targets, when they do. It also changes a couple
of tests to avoid depending on floating-point std::to_chars when
it isn't fundamental to the test.

Finally, some tests are marked as XFAIL but I added a comment saying

   TODO FMT This test should not require std::to_chars(floating-point)

These tests do not fundamentally depend on floating-point std::to_chars,
however they end up failing because calling std::format even without a
floating-point argument to format will end up requiring floating-point
std::to_chars. I believe this is an implementation artifact that could
be avoided in all cases where we know the format string at compile-time.
In the tests, I added the TODO comment only to the places where we could
do better and actually avoid relying on floating-point std::to_chars
because we know the format string at compile-time.

Differential Revision: https://reviews.llvm.org/D134598
2023-03-22 16:32:26 -04:00
Mark de Wever
f68a536a67 [libc++][format] Addresses LWG3839.
LWG3839 range_formatter's set_separator, set_brackets, and
  underlying functions should be noexcept

Adds tests for:

  template<ranges::input_range R, class charT>
     struct range-default-formatter<range_format::sequence, R, charT>

These were missing, the format functions tests for the sequences
are already present.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D144286
2023-03-07 19:20:19 +01:00
Nikolas Klauser
4f15267d3d [libc++][NFC] Replace _LIBCPP_STD_VER > x with _LIBCPP_STD_VER >= x
This change is almost fully mechanical. The only interesting change is in `generate_feature_test_macro_components.py` to generate `_LIBCPP_STD_VER >=` instead. To avoid churn in the git-blame this commit should be added to the `.git-blame-ignore-revs` once committed.

Reviewed By: ldionne, var-const, #libc

Spies: jloser, libcxx-commits, arichardson, arphaman, wenlei

Differential Revision: https://reviews.llvm.org/D143962
2023-02-15 16:52:25 +01:00
Louis Dionne
a845b5b4fb [libc++] Use bounded iterators in std::string_view when the debug mode is enabled
Differential Revision: https://reviews.llvm.org/D142903
2023-01-31 18:23:46 -05:00
Mark de Wever
0729010488 [NFC][libc++][format] Uses retarget buffer.
Lets the tuple formatter use the retarget buffer added for the range
formatter.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D142838
2023-01-31 19:54:53 +01:00
Mark de Wever
eb6e13cb32 [libc++][format] Adds formatter for tuple and pair
Implements parts of
- P2286R8 Formatting Ranges

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D136775
2022-12-22 19:36:28 +01:00