6 Commits

Author SHA1 Message Date
Louis Dionne
6e1dcc9335 [libc++] Refactor string unit tests to ease addition of new allocators
While doing this, I also found a few tests that were either clearly
incorrect (e.g. testing the wrong function) or that lacked basic test
coverage like testing std::string itself (e.g. the test was only checking
std::basic_string with a custom allocator). In these cases, I did a few
conservative drive-by changes.

Differential Revision: https://reviews.llvm.org/D140550
Co-authored-by: Brendan Emery <brendan.emery@esrlabs.com>
2023-09-27 09:01:58 -04:00
Brendan Emery
a40bada91a [libc++] Apply clang formatting to all string unit tests
This applies clang-format to the std::string unit tests in preparation
for landing https://reviews.llvm.org/D140550.

Differential Revision: https://reviews.llvm.org/D140612
2023-09-01 13:35:18 -04:00
Nikolas Klauser
425620ccdd [libc++] Implement P0980R1 (constexpr std::string)
Reviewed By: #libc, ldionne

Spies: daltenty, sdasgup3, ldionne, arichardson, MTC, ChuanqiXu, mehdi_amini, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, stephenneuendorffer, Joonsoo, grosul1, Kayjukh, jurahul, msifontes, tatianashp, rdzhabarov, teijeong, cota, dcaballe, Chia-hungDuan, wrengr, wenzhicui, arphaman, Mordante, miscco, Quuxplusone, smeenai, libcxx-commits

Differential Revision: https://reviews.llvm.org/D110598
2022-04-27 12:25:34 +02:00
Nikolas Klauser
85e9b2687a [libc++] Prepare string tests for constexpr
These are the last™ changes to the tests for constexpr preparation.

Reviewed By: Quuxplusone, #libc, Mordante

Spies: Mordante, EricWF, libcxx-commits

Differential Revision: https://reviews.llvm.org/D120951
2022-03-19 18:48:14 +01:00
Nikolas Klauser
dcffa7d3e1 [libc++] Prepare string.modifiers tests for constexpr
Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D119329
2022-02-10 21:43:18 +01:00
Arthur O'Dwyer
e87479b00f [libc++] Remove the special logic for "noexcept iterators" in basic_string.
This reverts a large chunk of http://reviews.llvm.org/D15862 ,
and also fixes bugs in `insert`, `append`, and `assign`, which are now regression-tested.
(Thanks to Tim Song for pointing out the bug in `append`!)

Before this patch, we did a special dance in `append`, `assign`, and `insert`
(but not `replace`). All of these require the strong exception guarantee,
even when the user-provided InputIterator might have throwing operations.

The naive way to accomplish this is to construct a temporary string and
then append/assign/insert from the temporary; i.e., finish all the potentially
throwing and self-inspecting InputIterator operations *before* starting to
modify self. But this is slow, so we'd like to skip it when possible.

The old code (D15682) attempted to check that specific iterator operations
were nothrow: it assumed that if the iterator operations didn't throw, then
it was safe to iterate the input range multiple times and therefore it was
safe to use the fast-path non-naive version. This was wrong for two reasons:
(1) the old code checked the wrong operations (e.g. checked noexceptness of `==`,
but the code that ran used `!=`), and (2) the conversion of value_type to char
could still throw, or inspect the contents of self.

The new code is much simpler, although still much more complicated than it
really could be. We'll likely revisit this codepath at some point, but for now
this patch suffices to get it passing all the new regression tests.

The added tests all fail before this patch, and succeed afterward.
See https://quuxplusone.github.io/blog/2021/04/17/pathological-string-appends/

Differential Revision: https://reviews.llvm.org/D98573
2021-04-26 16:22:43 -04:00