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

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

* Default-initialized `basic_string` iterators are not portably in the domain of `==`.
* Avoid comparing iterators from non-equal string_views which MSVCSTL considers not to be in the domain of equality.
* Don't test invalid range `[in, out + N)`.

Also silence some truncation warnings by testing with a non-narrowing conversion.

Differential Revision: https://reviews.llvm.org/D118049

Fixes https://github.com/llvm/llvm-project/issues/52902

In debug mode during constant evaluation the iterator was never assigend. There seem to be no other instances of this bug.

Reviewed By: Quuxplusone, Mordante, #libc, ldionne

Spies: ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D116346

Some embedded platforms do not wish to support the C library functionality
for handling wchar_t because they have no use for it. It makes sense for
libc++ to work properly on those platforms, so this commit adds a carve-out
of functionality for wchar_t.

Unfortunately, unlike some other carve-outs (e.g. random device), this
patch touches several parts of the library. However, despite the wide
impact of this patch, I still think it is important to support this
configuration since it makes it much simpler to port libc++ to some
embedded platforms.

Differential Revision: https://reviews.llvm.org/D111265

This functionality is tested in std/containers/sequences/vector/iterators.pass.cpp
(and similarly for all containers, but vector is the only one to be tested that
uses debug iterators).

Differential Revision: https://reviews.llvm.org/D100881

C++98 and C++03 are effectively aliases as far as Clang is concerned.
As such, allowing both std=c++98 and std=c++03 as Lit parameters is
just slightly confusing, but provides no value. It's similar to allowing
both std=c++17 and std=c++1z, which we don't do.

This was discovered because we had an internal bot that ran the test
suite under both c++98 AND c++03 -- one of which is redundant.

Differential Revision: https://reviews.llvm.org/D80926

llvm-svn: 362252

Summary:
Freestanding is *weird*. The standard allows it to differ in a bunch of odd
manners from regular C++, and the committee would like to improve that
situation. I'd like to make libc++ behave better with what freestanding should
be, so that it can be a tool we use in improving the standard. To do that we
need to try stuff out, both with "freestanding the language mode" and
"freestanding the library subset".

Let's start with the super basic: run the libc++ tests in freestanding, using
clang as the compiler, and see what works. The easiest hack to do this:

In utils/libcxx/test/config.py add:

  self.cxx.compile_flags += ['-ffreestanding']

Run the tests and they all fail.

Why? Because in freestanding `main` isn't special. This "not special" property
has two effects: main doesn't get mangled, and main isn't allowed to omit its
`return` statement. The first means main gets mangled and the linker can't
create a valid executable for us to test. The second means we spew out warnings
(ew) and the compiler doesn't insert the `return` we omitted, and main just
falls of the end and does whatever undefined behavior (if you're luck, ud2
leading to non-zero return code).

Let's start my work with the basics. This patch changes all libc++ tests to
declare `main` as `int main(int, char**` so it mangles consistently (enabling us
to declare another `extern "C"` main for freestanding which calls the mangled
one), and adds `return 0;` to all places where it was missing. This touches 6124
files, and I apologize.

The former was done with The Magic Of Sed.

The later was done with a (not quite correct but decent) clang tool:

  https://gist.github.com/jfbastien/793819ff360baa845483dde81170feed

This works for most tests, though I did have to adjust a few places when e.g.
the test runs with `-x c`, macros are used for main (such as for the filesystem
tests), etc.

Once this is in we can create a freestanding bot which will prevent further
regressions. After that, we can start the real work of supporting C++
freestanding fairly well in libc++.

<rdar://problem/47754795>

Reviewers: ldionne, mclow.lists, EricWF

Subscribers: christof, jkorous, dexonsmith, arphaman, miyuki, libcxx-commits

Differential Revision: https://reviews.llvm.org/D57624

llvm-svn: 353086

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