[libc++][modules] Fix missing and incorrect includes (#108850)

This patch adds a large number of missing includes in the libc++ headers
and the test suite. Those were found as part of the effort to

[libc++][modules] Fix missing and incorrect includes (#108850)

This patch adds a large number of missing includes in the libc++ headers
and the test suite. Those were found as part of the effort to move
towards a mostly monolithic top-level std module.

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[libc++][math] Fix acceptance of convertible types in `std::isnan()` and `std::isinf()` (#98952)

Following up on https://github.com/llvm/llvm-project/pull/98841.

Changes:
- Properly test convert

[libc++][math] Fix acceptance of convertible types in `std::isnan()` and `std::isinf()` (#98952)

Following up on https://github.com/llvm/llvm-project/pull/98841.

Changes:
- Properly test convertible types for `std::isnan()` and `std::inf()`
- Tighten conditional in `cmath.pass.cpp` (Find insights on `_LIBCPP_PREFERRED_OVERLOAD` below)
- Tighten preprocessor guard in `traits.h`

Insights into why `_LIBCPP_PREFERRED_OVERLOAD` is needed:

(i) When libc++ is layered on top of glibc on Linux, glibc's `math.h` is
included. When compiling with `-std=c++03`, this header brings the
function declaration of `isinf(double)` [1] and `isnan(double)` [2]
into scope. This differs from the C99 Standard as only the macros
`#define isnan(arg)` and `#define isinf(arg)` are expected.

Therefore, libc++ needs to respect the presense of the `double` overload
and cannot redefine it as it will conflict with the declaration already
in scope. For `-std=c++11` and beyond this issue is fixed, as glibc
guards both the `isinf` and `isnan` by preprocessor macros.

(ii) When libc++ is layered on top of Bionic's libc, `math.h` exposes a
function prototype for `isinf(double)` with return type `int`. This
function prototype in Bionic's libc is not guarded by any preprocessor
macros [3].

`_LIBCPP_PREFERRED_OVERLOAD` specifies that a given overload is a better match
than an otherwise equally good function declaration. This is implemented in
modern versions of Clang via `__attribute__((__enable_if__))`, and not elsewhere.
See [4] for details. We use `_LIBCPP_PREFERRED_OVERLOAD` to define overloads in
the global namespace that displace the overloads provided by the C
libraries mentioned above.

[1]: https://github.com/bminor/glibc/blob/fe9408087583fd7a6f61bb0dbcf2fd4e83186afa/math/bits/mathcalls.h#L185-L194
[2]: https://github.com/bminor/glibc/blob/fe9408087583fd7a6f61bb0dbcf2fd4e83186afa/math/bits/mathcalls.h#L222-L231
[3]: https://cs.android.com/android/platform/superproject/+/master:bionic/libc/include/math.h;l=322-323;drc=master?hl=fr-BE%22https:%2F%2Fsupport.google.com%2Fmerchants%2Fanswer%2F188494%5C%22%22https:%2F%2Fsupport.google.com%2Fmerchants%2Fanswer%2F188494%5C%22
[4]: https://github.com/llvm/llvm-project/commit/5fd17ab1b093f6b59aabb27f6c2c2278e65c2707

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[libc++][math] Fix undue overflowing of `std::hypot(x,y,z)` (#100820)

This is in relation to mr #93350. It was merged to main, but reverted
because of failing sanitizer builds on PowerPC.

The fi

[libc++][math] Fix undue overflowing of `std::hypot(x,y,z)` (#100820)

This is in relation to mr #93350. It was merged to main, but reverted
because of failing sanitizer builds on PowerPC.

The fix includes replacing the hard-coded threshold constants (e.g.
`__overflow_threshold`) for different floating-point sizes by a general
computation using `std::ldexp`. Thus, it should now work for all architectures.
This has the drawback of not being `constexpr` anymore as `std::ldexp`
is not implemented as `constexpr` (even though the standard mandates it
for C++23).

Closes #92782

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Revert "[libc++][math] Fix undue overflowing of `std::hypot(x,y,z)` (#93350)"

This reverts commit 9628777479a970db5d0c2d0b456dac6633864760.

More details in https://github.com/llvm/llvm-project/pull

Revert "[libc++][math] Fix undue overflowing of `std::hypot(x,y,z)` (#93350)"

This reverts commit 9628777479a970db5d0c2d0b456dac6633864760.

More details in https://github.com/llvm/llvm-project/pull/93350, but
this broke the PowerPC sanitizer bots.

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[libc++] Add clang-20 to failing tests on Windows (#100119)

After we switched to LLVM version 20, some libc++ tests started failing
on Windows. This patch adds the clang-20 condition to XFAIL to fi

[libc++] Add clang-20 to failing tests on Windows (#100119)

After we switched to LLVM version 20, some libc++ tests started failing
on Windows. This patch adds the clang-20 condition to XFAIL to fix the
issue. The way that these tests are excluded from Windows are fragile
and need to be updated every time we bump the LLVM version.

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[libc++][math] Fix undue overflowing of `std::hypot(x,y,z)` (#93350)

The 3-dimentionsional `std::hypot(x,y,z)` was sub-optimally implemented.
This lead to possible over-/underflows in (intermediate

[libc++][math] Fix undue overflowing of `std::hypot(x,y,z)` (#93350)

The 3-dimentionsional `std::hypot(x,y,z)` was sub-optimally implemented.
This lead to possible over-/underflows in (intermediate) results which
can be circumvented by this proposed change.

The idea is to to scale the arguments (see linked issue for full
discussion).

Tests have been added for problematic over- and underflows.

Closes #92782

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[libc++] Add clang-19 to failing tests on Windows (#79619)

After trunk is bumped to version 19, some libc++ tests started failing
on Windows. This patch adds clang-19 condition to XFAIL to fix the

[libc++] Add clang-19 to failing tests on Windows (#79619)

After trunk is bumped to version 19, some libc++ tests started failing
on Windows. This patch adds clang-19 condition to XFAIL to fix the
issue.

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[libcxx] Amend XFAIL for failing tests on Windows (#70422)

Some tests starting passing/failing after #69431 because Clang no longer
enables -fdelayed-template-parsing by default on Windows with C++

[libcxx] Amend XFAIL for failing tests on Windows (#70422)

Some tests starting passing/failing after #69431 because Clang no longer
enables -fdelayed-template-parsing by default on Windows with C++20.

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[libc++] Add std::fpclassify overloads for floating-point. (#67913)

Standard says that implementation of math functions that have
floating-point-type parameter should provide an "overload for each

[libc++] Add std::fpclassify overloads for floating-point. (#67913)

Standard says that implementation of math functions that have
floating-point-type parameter should provide an "overload for each
cv-unqualified floating-point type".

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[libc++] Qualifies size_t.

This has been done using the following command

find libcxx/test -type f -exec perl -pi -e 's|^([^/]+?)((?<!::)size_t)|\1std::\2|' \{} \;

And manually removed some fals

[libc++] Qualifies size_t.

This has been done using the following command

find libcxx/test -type f -exec perl -pi -e 's|^([^/]+?)((?<!::)size_t)|\1std::\2|' \{} \;

And manually removed some false positives in std/depr/depr.c.headers.

The `std` module doesn't export `::size_t`, this is a preparation for that module.

Reviewed By: ldionne, #libc, EricWF, philnik

Differential Revision: https://reviews.llvm.org/D146088

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[libc++] Add warning pragma macros in the test suite

Reviewed By: ldionne, #libc, EricWF

Spies: EricWF, libcxx-commits

Differential Revision: https://reviews.llvm.org/D121552

[libc++][AIX] Use C++ overloads from libc++'s math.h

AIX's system header provides these C++ overloads for compatibility with
older XL C++ implementations, but they can be disabled by defining
__LIBC

[libc++][AIX] Use C++ overloads from libc++'s math.h

AIX's system header provides these C++ overloads for compatibility with
older XL C++ implementations, but they can be disabled by defining
__LIBC_NO_CPP_MATH_OVERLOADS__ since AIX 7.2 TL 5 SP 3.

Since D109078 landed clang will define this macro when using libc++ on
AIX and we already run the lit tests with it too. This change will
enable the overloads in libc++'s math.h and we'll continue to require
the compiler to define the macro going forward.

Reviewed By: ldionne, jsji, EricWF

Differential Revision: https://reviews.llvm.org/D102172

co-authored-by: Jason Liu <jasonliu.development@gmail.com>

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[libc++] Add missing templated version of `std::lerp`.

Fixes #50806.

Differential Revision: https://reviews.llvm.org/D116295

[libc++] [test] Remove an erroneously copy-paste in the hypot() tests. NFC.

Line 1140 is a duplicate of line 1119; it tests the two-argument version
of std::hypot, whereas all the lines in this sect

[libc++] [test] Remove an erroneously copy-paste in the hypot() tests. NFC.

Line 1140 is a duplicate of line 1119; it tests the two-argument version
of std::hypot, whereas all the lines in this section are supposed to be
testing the C++17 three-argument version. Remove the erroneous duplicated line.

Split out of D116295.

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[libc++][CI] Add AIX pipeline config

This changes adds the pipeline config for both 32-bit and 64-bit AIX targets. As well, we add a lit feature `LIBCXX-AIX-FIXME` which is used to mark the failing

[libc++][CI] Add AIX pipeline config

This changes adds the pipeline config for both 32-bit and 64-bit AIX targets. As well, we add a lit feature `LIBCXX-AIX-FIXME` which is used to mark the failing tests which remain to be investigated on AIX, so that the CI produces a clean build.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D111359

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Fix implementation of ::abs and std::abs LWG 2192.

Summary:
All overloads of `::abs` and `std::abs` must be present in both `<cmath>` and `<cstdlib>`. This is problematic to implement because C defi

Fix implementation of ::abs and std::abs LWG 2192.

Summary:
All overloads of `::abs` and `std::abs` must be present in both `<cmath>` and `<cstdlib>`. This is problematic to implement because C defines `fabs` in `math.h` and `labs` in `stdlib.h`. This introduces a circular dependency between the two headers.

This patch implements that requirement by moving `abs` into `math.h` and making `stdlib.h` include `math.h`. In order to get the underlying C declarations from the "real" `stdlib.h` inside our `math.h` we need some trickery. Specifically we need to make `stdlib.h` include next itself.

Suggestions for a cleaner implementation are welcome.

Reviewers: mclow.lists, ldionne

Reviewed By: ldionne

Subscribers: krytarowski, fedor.sergeev, dexonsmith, jdoerfert, jsji, libcxx-commits

Differential Revision: https://reviews.llvm.org/D60097

llvm-svn: 359020

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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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Fix FP comparisons when SSE isn't available

llvm-svn: 349387

Fix return type of isinf(double) and isnan(double) where possible.

When using an old version of glibc, a ::isinf(double) and ::isnan(double)
function is provided, rather than just the macro required

Fix return type of isinf(double) and isnan(double) where possible.

When using an old version of glibc, a ::isinf(double) and ::isnan(double)
function is provided, rather than just the macro required by C and C++.
Displace this function using _LIBCPP_PREFERRED_OVERLOAD where possible.

The only remaining case where we should get the wrong return type is now
glibc + libc++ + a non-clang compiler.

llvm-svn: 331241

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cmath: Skip Libc for integral types in isinf, etc.

For std::isinf, the standard requires effectively calling isinf as
double from Libc for integral types. But integral types are never
infinite; we d

cmath: Skip Libc for integral types in isinf, etc.

For std::isinf, the standard requires effectively calling isinf as
double from Libc for integral types. But integral types are never
infinite; we don't need to call Libc to return false.

Also short-circuit other functions where Libc won't have interesting
answers: signbit, fpclassify, isfinite, isnan, and isnormal.

I added correctness tests for integral types since we're no longer
deferring to Libc.

In review it was pointed out that in future revisions of the C++
standard we may add more types to std::is_arithmetic (e.g.,
std::is_fixed_point). I'll leave it to a future commit to hack this to
allow using math functions on those. We'll need to change things like
__libcpp_fpclassify anyway, so I'm not sure anything here would really
be future-proof.

https://reviews.llvm.org/D31561
rdar://problem/31361223

llvm-svn: 301060

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Replace __cplusplus comparisons and dialect __has_feature checks with TEST_STD_VER.

This is a huge cleanup that helps make the libc++ test suite more portable.
Patch from STL@microsoft.com. Thanks S

Replace __cplusplus comparisons and dialect __has_feature checks with TEST_STD_VER.

This is a huge cleanup that helps make the libc++ test suite more portable.
Patch from STL@microsoft.com. Thanks STL!

llvm-svn: 272716

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Remove trailing whitespace in test suite. Approved by Marshall Clow.

llvm-svn: 271435

Tolerate incorrect return type for 'isinf' and 'isnan' in tests.

Summary:
GLIBC recently removed the incorrect `int isinf(double)` and `int isnan(double)` overloads in C++11 and greater. This causes

Tolerate incorrect return type for 'isinf' and 'isnan' in tests.

Summary:
GLIBC recently removed the incorrect `int isinf(double)` and `int isnan(double)` overloads in C++11 and greater. This causes previously `XFAIL: linux` tests to start passing.

Since there is no longer a way to 'XFAIL' the tests I choose to simply tolerate this bug.

See https://sourceware.org/bugzilla/show_bug.cgi?id=19439


Reviewers: rsmith, mclow.lists, EricWF

Subscribers: jroelofs, cfe-commits

Differential Revision: http://reviews.llvm.org/D19835

llvm-svn: 271060

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Implement P0030R1: Introduce a 3-Argument Overload to std::hypot

llvm-svn: 269772