There are a handful of standard library types that are intended
to support CTAD but don't need any explicit deduction guides to
do so.
This patch adds a dummy deduction guide to those types to suppress
-Wctad-maybe-unsupported (which gets emitted in user code).
This is a re-application of the original patch by Eric Fiselier in
fcd549a7d8 which had been reverted due to reasons lost at this point.
I also added the macro to a few more types. Reviving this patch was
prompted by the discussion on https://llvm.org/D133425.
Differential Revision: https://reviews.llvm.org/D133535
Noticed this while working on D133326. Let's see whehter all compilers
now support this feature.
Reviewed By: #libc, philnik, ldionne
Differential Revision: https://reviews.llvm.org/D134818
While testing a test failure of C++17 with Clang ToT it was noticed the
paper
P0602R4 variant and optional should propagate copy/move triviality
was not applied as a DR in libc++.
This was discovered while investigating the issue "caused by" D131479.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D133326
... it's easier to suppress warnings internally, where we can detect the compiler.
* Rename `TEST_COMPILER_C1XX` to `TEST_COMPILER_MSVC`
* Rename all `TEST_WORKAROUND_C1XX_<meow>` to `TEST_WORKAROUND_MSVC_<meow>`
Differential Revision: https://reviews.llvm.org/D117422
Even if these comments have a benefit in .h files (for editors that
care about language but can't be configured to treat .h as C++ code),
they certainly have no benefit for files with the .cpp extension.
Discussed in D110794.
Now that Lit supports regular expressions inside XFAIL & friends, it is
much easier to write Lit annotations based on the triple.
Differential Revision: https://reviews.llvm.org/D104747
This fixes a long standing issue where the triple is not always set
consistently in all configurations. This change also moves the
back-deployment Lit features to using the proper target triple
instead of using something ad-hoc.
This will be necessary for using from scratch Lit configuration files
in both normal testing and back-deployment testing.
Differential Revision: https://reviews.llvm.org/D102012
Some time ago, I introduced shortcut features like dylib-has-no-shared_mutex
to encode whether the deployment target supported shared_mutex (say). This
made the test suite annotations cleaner.
However, the problem with building Lit features on top of other Lit
features is that it's easier for them to become stale, especially when
they are generated programmatically. Furthermore, it makes the bar for
defining configurations from scratch higher, since more features have
to be defined. Instead, I think it's better to put the XFAILs in the
tests directly, which allows cleaning them up with a simple grep.
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
Instead of having different names for the same Lit feature accross code
bases, use the same name everywhere. This NFC commit is in preparation
for a refactor where all three projects will be using the same Lit
feature detection logic, and hence it won't be convenient to use
different names for the feature.
Differential Revision: https://reviews.llvm.org/D78370
* Add the conventional `return 0` to `main` in `variant.assign/conv.pass.cpp` and `variant.ctor/conv.pass.cpp`
* Fix some MSVC signed-to-unsigned conversion warnings by replacing `int` literarls with `unsigned int` literals
llvm-svn: 374723
The standard disallows narrowing conversions when constructing a variant.
This is checked by attempting to perform braced initialization of the
destination type from the argument type. However, braced initialization
can force the compiler (mostly clang) to eagerly instantiate the
constructors of the destintation type -- which can lead to errors in
a non-immediate context.
However, as variant is currently specified, the narrowing checks only
observably apply when the destination type is arithmetic. Meaning we can
skip the check for class types. Hense avoiding the hard errors.
In order to cause fewer build breakages, this patch avoids the narrowing
check except when the destination type is arithmetic.
llvm-svn: 366022
The paper P0608R3 - "A sane variant converting constructor" disallows
narrowing conversions in variant. It was meant to address this
surprising problem:
std::variant<std::string, bool> v = "abc";
assert(v.index() == 1); // constructs a bool.
However, it also disables every potentially narrowing conversion. For
example:
variant<unsigned> v = 0; // ill-formed
variant<string, double> v2 = 42; // ill-formed (int -> double narrows)
These latter changes break code. A lot of code. Within Google it broke
on the order of a hundred thousand target with thousands of root causes
responsible for the breakages.
Of the breakages related to the narrowing restrictions, none of them
exposed outstanding bugs. However, the breakages caused by boolean
conversions (~13 root causes), all but one of them were bugs.
For this reasons, I am adding a flag to disable the narrowing conversion
changes but not the boolean conversions one.
One purpose of this flag is to allow users to opt-out of breaking changes
in variant until the offending code can be cleaned up. For non-trivial
variant usages the amount of cleanup may be significant.
This flag is also required to support automated tooling, such as
clang-tidy, that can automatically fix code broken by this change.
In order for clang-tidy to know the correct alternative to construct,
it must know what alternative was being constructed previously, which
means running it over the old version of std::variant.
Because this change breaks so much code, I will be implementing the
aforementioned clang-tidy check in the very near future.
Additionally I'm plan present this new information to the committee so they can
re-consider if this is a breaking change we want to make.
I think libc++ should very seriously consider pulling this change
before the 9.0 release branch is cut. But that's a separate discussion
that I will start on the lists.
For now this is the minimal first step.
llvm-svn: 365960
Some tests are marked as failing on platforms where the dylib does not
provide the required exception classes. However, when testing with
exceptions disabled, those tests shouldn't be marked as failing.
llvm-svn: 353210
This patch removes some vendor-specific availability XFAILs from the
test suite. In the future, when a new feature is introduced in the
dylib, an availability macro should be created and a matching lit
feature should be created. That way, the test suite can XFAIL whenever
the implementation lacks the necessary feature instead of being
cluttered by vendor-specific annotations.
Right now, those vendor-specific annotations are still somewhat cluttering
the test suite by being in `config.py`, but at least they are localized.
In the future, we could design a way to define those less intrusively or
even automatically based on the availability macros that already exist
in <__config>.
llvm-svn: 353201
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
Summary:
P0602R4 makes the special member functions of optional and variant
conditionally trivial based on the types in the optional/variant.
We already implemented that, but the tests were organized as if this
were a non-standard extension. This patch reorganizes the tests in a
way that makes more sense since this is not an extension anymore.
Reviewers: EricWF, mpark, mclow.lists
Subscribers: christof, jkorous, dexonsmith, libcxx-commits
Differential Revision: https://reviews.llvm.org/D54772
llvm-svn: 350884
Summary:
In PR39232, we noticed that some variant tests started failing in C++2a mode
with recent Clangs, because the rules for literal types changed in C++2a. As
a result, a temporary fix was checked in (enabling the test only in C++17).
This commit is what I believe should be the long term fix: I removed the
tests that checked constexpr default-constructibility with a weird type
from the tests for index() and valueless_by_exception(), and instead I
added tests for those using an obviously literal type in the test for the
default constructor.
Reviewers: EricWF, mclow.lists
Subscribers: christof, jkorous, dexonsmith, arphaman, libcxx-commits, rsmith
Differential Revision: https://reviews.llvm.org/D54767
llvm-svn: 347568
This patch works around variant test failures which are new to
GCC 8. GCC 8 either doesn't perform SFINAE in lexical order, or
it doesn't halt after encountering the first failure. This
causes hard error to occur instead of substitution failure.
See gcc.gnu.org/PR78489
llvm-svn: 328261
Remarks: This function shall not participate in overload resolution unless
`is_same_v<decay_t<T>, variant>` is false, unless `decay_t<T>` is
neither a specialization of `in_place_type_t` nor a specialization of
`in_place_index_t`, unless `is_constructible_v<Tj, T>` is true, and
unless the expression `FUN(std::forward<T>(t))` (with `FUN` being the
above-mentioned set of imaginary functions) is well formed.
Depends on D34111.
Reviewers: EricWF, K-ballo
Reviewed By: EricWF
Subscribers: fhahn
Differential Revision: https://reviews.llvm.org/D34112
llvm-svn: 305668
Also: Move constexpr / triviality extension tests into the std tree and make them conditional on _LIBCPP_VERSION / _MSVC_STL_VERSION.
https://reviews.llvm.org/D32671
llvm-svn: 304847
The tests were previously guarded by #if defined(_LIBCPP_VER) || defined(_MSVC_STL_VER),
which is both incorrect (e.g. _LIBCPP_VERSION) and unneeded. Although the tests are
technically non-standard (yet) they are supported by both libc++ and MSVC's STL.
libstdc++ doesn't regularly use the test suite so I'm not concerned about guarding these
tests for them.
llvm-svn: 303953
Libc++ is used as a system library on macOS and iOS (amongst others). In order
for users to be able to compile a binary that is intended to be deployed to an
older version of the platform, clang provides the
availability attribute <https://clang.llvm.org/docs/AttributeReference.html#availability>_
that can be placed on declarations to describe the lifecycle of a symbol in the
library.
See docs/DesignDocs/AvailabilityMarkup.rst for more information.
Differential Revision: https://reviews.llvm.org/D31739
llvm-svn: 302172
Louis Dionne