We've accumulated a scary amount of local patches to this directory. I
tried to merge them all, but if your favorite change is missing please
reapply it manually (and send it upstream).
Current code breaks this version of MSVC due to a mismatch between `std::is_trivially_copyable` and `llvm::is_trivially_copyable` for `std::pair` instantiations. Hence I was attempting to use `std::is_trivially_copyable` to set `llvm::is_trivially_copyable<T>::value`.
I spent some time root causing an `llvm::Optional` build error on MSVC 16.8.3 related to the change described above:
```
62>C:\src\ocg_llvm\llvm-project\llvm\include\llvm/ADT/BreadthFirstIterator.h(96,12): error C2280: 'llvm::Optional<std::pair<std::pair<unsigned int,llvm::Graph<4>::NodeSubset> *,llvm::Optional<llvm::Graph<4>::ChildIterator>>> &llvm::Optional<std::pair<std::pair<unsigned int,llvm::Graph<4>::NodeSubset> *,llvm::Optional<llvm::Graph<4>::ChildIterator>>>::operator =(const llvm::Optional<std::pair<std::pair<unsigned int,llvm::Graph<4>::NodeSubset> *,llvm::Optional<llvm::Graph<4>::ChildIterator>>> &)': attempting to reference a deleted function (compiling source file C:\src\ocg_llvm\llvm-project\llvm\unittests\ADT\BreadthFirstIteratorTest.cpp)
...
```
The "trivial" specialization of `optional_detail::OptionalStorage` assumes that the value type is trivially copy constructible and trivially copy assignable. The specialization is invoked based on a check of `is_trivially_copyable` alone, which does not imply both `is_trivially_copy_assignable` and `is_trivially_copy_constructible` are true.
[[ https://en.cppreference.com/w/cpp/named_req/TriviallyCopyable | According to the spec ]], a deleted assignment operator does not make `is_trivially_copyable` false. So I think all these properties need to be checked explicitly in order to specialize `OptionalStorage` to the "trivial" version:
```
/// Storage for any type.
template <typename T, bool = std::is_trivially_copy_constructible<T>::value
&& std::is_trivially_copy_assignable<T>::value>
class OptionalStorage {
```
Above fixed my build break in MSVC, but I think we need to explicitly check `is_trivially_copy_constructible` too since it might be possible the copy constructor is deleted. Also would be ideal to move over to `std::is_trivially_copyable` instead of the `llvm` namespace verson.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D93510
Current code breaks this version of MSVC due to a mismatch between `std::is_trivially_copyable` and `llvm::is_trivially_copyable` for `std::pair` instantiations. Hence I was attempting to use `std::is_trivially_copyable` to set `llvm::is_trivially_copyable<T>::value`.
I spent some time root causing an `llvm::Optional` build error on MSVC 16.8.3 related to the change described above:
```
62>C:\src\ocg_llvm\llvm-project\llvm\include\llvm/ADT/BreadthFirstIterator.h(96,12): error C2280: 'llvm::Optional<std::pair<std::pair<unsigned int,llvm::Graph<4>::NodeSubset> *,llvm::Optional<llvm::Graph<4>::ChildIterator>>> &llvm::Optional<std::pair<std::pair<unsigned int,llvm::Graph<4>::NodeSubset> *,llvm::Optional<llvm::Graph<4>::ChildIterator>>>::operator =(const llvm::Optional<std::pair<std::pair<unsigned int,llvm::Graph<4>::NodeSubset> *,llvm::Optional<llvm::Graph<4>::ChildIterator>>> &)': attempting to reference a deleted function (compiling source file C:\src\ocg_llvm\llvm-project\llvm\unittests\ADT\BreadthFirstIteratorTest.cpp)
...
```
The "trivial" specialization of `optional_detail::OptionalStorage` assumes that the value type is trivially copy constructible and trivially copy assignable. The specialization is invoked based on a check of `is_trivially_copyable` alone, which does not imply both `is_trivially_copy_assignable` and `is_trivially_copy_constructible` are true.
[[ https://en.cppreference.com/w/cpp/named_req/TriviallyCopyable | According to the spec ]], a deleted assignment operator does not make `is_trivially_copyable` false. So I think all these properties need to be checked explicitly in order to specialize `OptionalStorage` to the "trivial" version:
```
/// Storage for any type.
template <typename T, bool = std::is_trivially_copy_constructible<T>::value
&& std::is_trivially_copy_assignable<T>::value>
class OptionalStorage {
```
Above fixed my build break in MSVC, but I think we need to explicitly check `is_trivially_copy_constructible` too since it might be possible the copy constructor is deleted. Also would be ideal to move over to `std::is_trivially_copyable` instead of the `llvm` namespace verson.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D93510
Add a `hash_value` for Optional so that other data structures with
optional fields can easily hash them. I have a use for this in an
upcoming patch.
Differential Revision: https://reviews.llvm.org/D92676
`OptionalTest` was empty; drop it and switch all the tests to use the
shorter `TEST` instead of `TEST_F`.
Differential Revision: https://reviews.llvm.org/D92675
Revert "Delete llvm::is_trivially_copyable and CMake variable HAVE_STD_IS_TRIVIALLY_COPYABLE"
This reverts commit 4d4bd40b578d77b8c5bc349ded405fb58c333c78.
This reverts commit 557b00e0afb2dc1776f50948094ca8cc62d97be4.
We previously had to guard against older MSVC and GCC versions which had rvalue
references but not support for marking functions with ref qualifiers. However,
having bumped our minimum required version to MSVC 2017 and GCC 5.1 mean we can
unconditionally enable this feature. Rather than keeping the macro around, this
replaces use of the macro with the actual ref qualifier.
This is a follow-up to r354246 and a reimplementation of https://reviews.llvm.org/D57097?id=186600
that should not trigger any UB thanks to the use of an union.
This may still be subject to the problem solved by std::launder, but I'm unsure how it interacts whith union.
/me plans to revert if this triggers any relevant bot failure. At least this validates in Release mode with
clang 6.0.1 and gcc 4.8.5.
llvm-svn: 354264
and
r354055 "Optional specialization for trivially copyable types, part2"
These are suspected to cause Clang to get miscompiled on Ubuntu 14.04
(Trusty) which uses GCC 4.8.4. Reverting for an hour to see if this
helps. See llvm-commits thread.
> Recommit Optional specialization for trivially copyable types
>
> Unfortunately the original code gets misscompiled by GCC (at least 8.1),
> this is a tentative workaround using std::memcpy instead of inplace new
> for trivially copyable types. I'll revert if it breaks.
>
> Original revision: https://reviews.llvm.org/D57097
llvm-svn: 354126
Unfortunately the original code gets misscompiled by GCC (at least 8.1),
this is a tentative workaround using std::memcpy instead of inplace new
for trivially copyable types. I'll revert if it breaks.
Original revision: https://reviews.llvm.org/D57097
llvm-svn: 354051
Specialization of Optional for trivially copyable types yields failure on the buildbots I fail to reproduce locally.
Better safe than sorry, reverting.
llvm-svn: 353982
Make llvm::Optional<T> trivially copyable when T is trivially copyable
This is an ever-recurring issue (see https://bugs.llvm.org/show_bug.cgi?id=39427 and https://bugs.llvm.org/show_bug.cgi?id=35978)
but I believe that thanks to https://reviews.llvm.org/D54472 we can now ship a decent implementation of this.
Basically the fact that llvm::is_trivially_copyable has a consistent behavior across compilers should prevent any ABI issue,
and using in-place new instead of memcpy should keep compiler bugs away.
This patch is slightly different from the original revision https://reviews.llvm.org/rL353927 but achieves the same goal. It just avoids
going through std::conditional which may the code more explicit.
llvm-svn: 353962
This version of gcc seems to be having issues with raw literals inside macro
arguments. I change the string to use regular string literals instead.
llvm-svn: 351756
to reflect the new license.
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: 351636
Summary:
The operators simply print the underlying value or "None".
The trickier part of this patch is making sure the streaming operators
work even in unit tests (which was my primary motivation, though I can
also see them being useful elsewhere). Since the stream operator was a
template, implicit conversions did not kick in, and our gtest glue code
was explicitly introducing an implicit conversion to make sure other
implicit conversions do not kick in :P. I resolve that by specializing
llvm_gtest::StreamSwitch for llvm:Optional<T>.
Reviewers: sammccall, dblaikie
Reviewed By: sammccall
Subscribers: mgorny, dexonsmith, kristina, llvm-commits
Differential Revision: https://reviews.llvm.org/D56795
llvm-svn: 351548
This brings it in line with std::optional. My recent changes to
make Optional of trivial types trivially copyable introduced
diverging behavior depending on the type, which is bad. Now all
types have the same moving behavior.
llvm-svn: 323445
While the memmove workaround fixed it for GCC 6.3. GCC 4.8 and GCC 7.1
are still broken. I have no clue what's going on, just blacklist GCC for
now.
Needless to say this code is ubsan, asan and msan-clean.
llvm-svn: 322862
This makes uses of Optional more transparent to the compiler (and
clang-tidy) and generates slightly smaller code.
This is a re-land of r317019, which had issues with GCC 4.8 back then.
Those issues don't reproduce anymore, but I'll watch the buildbots
closely in case anything goes wrong.
llvm-svn: 322838
clang-format (https://reviews.llvm.org/D33932) to keep primary headers
at the top and handle new utility headers like 'gmock' consistently with
other utility headers.
No other change was made. I did no manual edits, all of this is
clang-format.
This should allow other changes to have more clear and focused diffs,
and is especially motivated by moving some headers into more focused
libraries.
llvm-svn: 304786
Summary: Make Optional's behavior the same as the coming std::optional.
Reviewers: dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D23178
llvm-svn: 278397
This is something like nullopt in std::experimental::optional. Optional
could already be constructed from None, so this seems like an obvious
extension from there.
I have a use in a future patch for Clang, though it may not go that
way/end up used - so this seemed worth committing now regardless.
llvm-svn: 245518
This can be used for in-place initialization of non-moveable types.
For compilers that don't support variadic templates, only up to four
arguments are supported. We can always add more, of course, but this
should be good enough until we move to a later MSVC that has full
support for variadic templates.
Inspired by std::experimental::optional from the "Library Fundamentals" C++ TS.
Reviewed by David Blaikie.
llvm-svn: 218732
This takes a single argument convertible to T, and
- if the Optional has a value, returns the existing value,
- otherwise, constructs a T from the argument and returns that.
Inspired by std::experimental::optional from the "Library Fundamentals" C++ TS.
llvm-svn: 218618
This generalizes Optional to require less from the T type by using aligned
storage for backing & placement new/deleting the T into it when necessary.
Also includes unit tests.
llvm-svn: 175580
