[libc++] Add regression test for #67449 (#67590)

Even though the underlying issue was fixed in #65177 when we made
std::pointer_traits SFINAE-friendly, it is worth adding a regression
test since i

[libc++] Add regression test for #67449 (#67590)

Even though the underlying issue was fixed in #65177 when we made
std::pointer_traits SFINAE-friendly, it is worth adding a regression
test since it's so easy to do.

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[libc++] Granularize the rest of memory

Reviewed By: ldionne, #libc

Spies: vitalybuka, paulkirth, libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D132790

Revert "[libc++] Granularize the rest of memory"

Breaks buildbots.

This reverts commit 30adaa730c4768b5eb06719c808b2884fcf53cf3.

[libc++] Granularize the rest of memory

Reviewed By: ldionne, #libc

Spies: libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D132790

[libc++] Fix std::to_address(array).

There were basically two bugs here:

When C++20 `to_address` is called on `int arr[10]`, then `const _Ptr&` becomes
a reference to a const array, and then we dis

[libc++] Fix std::to_address(array).

There were basically two bugs here:

When C++20 `to_address` is called on `int arr[10]`, then `const _Ptr&` becomes
a reference to a const array, and then we dispatch to `__to_address<const int(&)[10]>`,
which, oops, gives us a `const int*` result instead of an `int*` result.
Solution: We need to provide the two standard-specified overloads of
`std::to_address` in exactly the same way that we provide two overloads
of `__to_address`.

When `__to_address` is called on a pointer type, `__to_address(const _Ptr&)`
is disabled so we successfully avoid trying to instantiate pointer_traits of
that pointer type. But when it's called on an array type, it's not disabled
for array types, so we go ahead and instantiate pointer_traits<int[10]>,
which goes boom. Solution: We need to disable `__to_address(const _Ptr&)`
for both pointer and array types. Also disable it for function types,
so that they get the nice error message; and put a test on it.

Differential Revision: https://reviews.llvm.org/D109331

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[libc++] Rewrite std::to_address to avoid relying on element_type

This is a rough reapplication of the change that fixed std::to_address
to avoid relying on element_type (da456167). It is somewhat d

[libc++] Rewrite std::to_address to avoid relying on element_type

This is a rough reapplication of the change that fixed std::to_address
to avoid relying on element_type (da456167). It is somewhat different
because the fix to avoid breaking Clang (which caused it to be reverted
in 347f69c55) was a bit more involved.

Differential Revision: https://reviews.llvm.org/D101638

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[libc++] Revert the std::to_address change to avoid relying on element_type.

This reverts commit da456167, which broke the Clang build. I'm able to
reproduce it but I want to give myself a bit more

[libc++] Revert the std::to_address change to avoid relying on element_type.

This reverts commit da456167, which broke the Clang build. I'm able to
reproduce it but I want to give myself a bit more time to investigate.

Differential Revision: https://reviews.llvm.org/D101638

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[libc++] Make sure std::to_address doesn't depend on P::element_type.

Differential Revision: https://reviews.llvm.org/D101638

[libc++] [LWG3374] Mark `to_address(const Ptr& p)` overload `constexpr`.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D92659

[libc++] Remove the c++98 Lit feature from the test suite

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
ju

[libc++] Remove the c++98 Lit feature from the test suite

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

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Support tests in freestanding

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

Support tests in freestanding

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

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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

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

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[libcxx] Implement std::to_address for C++20

Summary: Now implements P0653R2 - Utility to convert to raw pointer.

Reviewers: mclow.lists, EricWF

Reviewed By: EricWF

Subscribers: cfe-commits

Diff

[libcxx] Implement std::to_address for C++20

Summary: Now implements P0653R2 - Utility to convert to raw pointer.

Reviewers: mclow.lists, EricWF

Reviewed By: EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D35470

llvm-svn: 318865

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