Part of the <=> changes in C++20 make certain patterns of writing equality
operators ambiguous with themselves (sorry!).
This patch goes through and adjusts all the comparison operators such that
they should work in both C++17 and C++20 modes. It also makes two other small
C++20-specific changes (adding a constructor to a type that cases to be an
aggregate, and adding casts from u8 literals which no longer have type
const char*).
There were four categories of errors that this review fixes.
Here are canonical examples of them, ordered from most to least common:
// 1) Missing const
namespace missing_const {
struct A {
#ifndef FIXED
bool operator==(A const&);
#else
bool operator==(A const&) const;
#endif
};
bool a = A{} == A{}; // error
}
// 2) Type mismatch on CRTP
namespace crtp_mismatch {
template <typename Derived>
struct Base {
#ifndef FIXED
bool operator==(Derived const&) const;
#else
// in one case changed to taking Base const&
friend bool operator==(Derived const&, Derived const&);
#endif
};
struct D : Base<D> { };
bool b = D{} == D{}; // error
}
// 3) iterator/const_iterator with only mixed comparison
namespace iter_const_iter {
template <bool Const>
struct iterator {
using const_iterator = iterator<true>;
iterator();
template <bool B, std::enable_if_t<(Const && !B), int> = 0>
iterator(iterator<B> const&);
#ifndef FIXED
bool operator==(const_iterator const&) const;
#else
friend bool operator==(iterator const&, iterator const&);
#endif
};
bool c = iterator<false>{} == iterator<false>{} // error
|| iterator<false>{} == iterator<true>{}
|| iterator<true>{} == iterator<false>{}
|| iterator<true>{} == iterator<true>{};
}
// 4) Same-type comparison but only have mixed-type operator
namespace ambiguous_choice {
enum Color { Red };
struct C {
C();
C(Color);
operator Color() const;
bool operator==(Color) const;
friend bool operator==(C, C);
};
bool c = C{} == C{}; // error
bool d = C{} == Red;
}
Differential revision: https://reviews.llvm.org/D78938
We determined that the MSVC implementation of std::aligned* isn't suited
to our needs. It doesn't support 16 byte alignment or higher, and it
doesn't really guarantee 8 byte alignment. See
https://github.com/microsoft/STL/issues/1533
Also reverts "ADT: Change AlignedCharArrayUnion to an alias of std::aligned_union_t, NFC"
Also reverts "ADT: Remove AlignedCharArrayUnion, NFC" to bring back
AlignedCharArrayUnion.
This reverts commit 4d8bf870a82765eb0d4fe53c82f796b957c05954.
This reverts commit d10f9863a5ac1cb681af07719650c44b48f289ce.
This reverts commit 4b5dc150b9862271720b3d56a3e723a55dd81838.
clang was complaing about this code:
llvm/include/llvm/IR/PassManager.h:715:17: error: ISO C++20 considers use of overloaded operator '!=' to be ambiguous despite there being a unique best viable function with non-reversed arguments [-Werror,-Wambiguous-reversed-operator]
if (IMapI != IsResultInvalidated.end())
~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~
llvm/include/llvm/ADT/DenseMap.h:1253:8: note: candidate function with non-reversed arguments
bool operator!=(const ConstIterator &RHS) const {
^
llvm/include/llvm/ADT/DenseMap.h:1246:8: note: ambiguous candidate function with reversed arguments
bool operator==(const ConstIterator &RHS) const {
^
The warning is triggered when the DenseMapIterator (lhs) is not const and so
the == operator is applied to different types on lhs/rhs.
Using a template allows the function to be available for both const/non-const
iterator types and gets rid of the warning
Prepare to delete `AlignedCharArrayUnion` by migrating its users over to
`std::aligned_union_t`.
I will delete `AlignedCharArrayUnion` and its tests in a follow-up
commit so that it's easier to revert in isolation in case some
downstream wants to keep using it.
Differential Revision: https://reviews.llvm.org/D92516
Update all the users of `AlignedCharArrayUnion` to stop peeking inside
(to look at `buffer`) so that a follow-up patch can replace it with an
alias to `std::aligned_union_t`.
This was reviewed as part of https://reviews.llvm.org/D92512, but I'm
splitting this bit out to commit first to reduce churn in case the
change to `AlignedCharArrayUnion` needs to be reverted for some
unexpected reason.
Revert "Delete llvm::is_trivially_copyable and CMake variable HAVE_STD_IS_TRIVIALLY_COPYABLE"
This reverts commit 4d4bd40b578d77b8c5bc349ded405fb58c333c78.
This reverts commit 557b00e0afb2dc1776f50948094ca8cc62d97be4.
There's an ABI breakage here if LLVM is compiled in C++14 without
aligned allocation and a user tries to use the result with aligned
allocation. If DenseMap or unique_function is used across that ABI
boundary it will break (PR45413). Moving it out of line is a bit of
a band-aid and LLVM doesn't really give ABI guarantees at this level,
but given the number of complaints I've received over this it still
seems worth fixing.
This code was added in 887efa51c1e0e43ca684ed78b92dbc3a0720881b to
fix reverse iteration.
The call to InsertIntoBucket/InsertIntoBucketWithLookup can change
the number of buckets which will invalidate the BucketEnd. So
don't cache it and calculate it when creating the iterator.
This patch gets the asserts working correctly when LLVM_REVERSE_ITERATION=On by fixing the iterators returned by the DenseMap::find* methods so that they return well-formed iterators that work with reverse iteration, and satisfy the assertions.
A recent change (4e86e5eedc6), broke `LLVM_REVERSE_ITERATION` for DenseMaps by adding an assert. It is valid to de-reference and increment one step behind `End` when reverse iteration is enabled because `End` is actually the start of the pointer bucket.
We can use it when just the value doesn't require destruction. Empty
keys are safe to overwrite always. This gets the important case of
std::pair values.
This patch is replacements missed in my last change doing this across LLVM.
No functional change, although I think there was a missing typename
in struct conjunction that is now fixed.
Fixes issue encountered in D56362, where I tried to use a
SmallSetVector<Instruction*, 128> with an excessively large number
of inline elements. This triggers an "Must allocate more buckets
than are inline" assertion inside allocateBuckets() under certain
usage patterns.
The issue is as follows: The grow() method is used either to grow
the map, or to rehash it and remove tombstones. The latter is done
if the fraction of empty (non-used, non-tombstone) elements is
below 1/8. In this case grow() is invoked with the current number
of buckets.
This is currently incorrectly handled for dense maps using the small
rep. The current implementation will switch them over to the large
rep, which violates the invariant that the large rep is only used
if there are more than InlineBuckets buckets.
This patch fixes the issue by staying in the small rep and only
moving the buckets. An alternative, if we do want to switch to the
large rep in this case, would be to relax the assertion in
allocateBuckets().
Differential Revision: https://reviews.llvm.org/D56455
This unlocks some goodies like sized deletion and gets the alignment
right on platforms that chose to provide a lower default new alignment.
llvm-svn: 371846
Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]
This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.
This is the command I ran and I to fix and format the code base:
```
run-clang-tidy.py \
-header-filter='.*' \
-checks='-*,modernize-use-nullptr' \
-fix ~/dev/llvm-project/lldb/.* \
-format \
-style LLVM \
-p ~/llvm-builds/debug-ninja-gcc
```
NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.
NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.
Reviewers: martong, espindola, shafik, #lldb, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D61847
llvm-svn: 361484
As noted in https://bugs.llvm.org/show_bug.cgi?id=36651, the specialization for
isPodLike<std::pair<...>> did not match the expectation of
std::is_trivially_copyable which makes the memcpy optimization invalid.
This patch renames the llvm::isPodLike trait into llvm::is_trivially_copyable.
Unfortunately std::is_trivially_copyable is not portable across compiler / STL
versions. So a portable version is provided too.
Note that the following specialization were invalid:
std::pair<T0, T1>
llvm::Optional<T>
Tests have been added to assert that former specialization are respected by the
standard usage of llvm::is_trivially_copyable, and that when a decent version
of std::is_trivially_copyable is available, llvm::is_trivially_copyable is
compared to std::is_trivially_copyable.
As of this patch, llvm::Optional is no longer considered trivially copyable,
even if T is. This is to be fixed in a later patch, as it has impact on a
long-running bug (see r347004)
Note that GCC warns about this UB, but this got silented by https://reviews.llvm.org/D50296.
Differential Revision: https://reviews.llvm.org/D54472
llvm-svn: 351701
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
Inheriting constructors from std::pair caused clang-3.8 to treat some DenseMap
initializer_list constructor calls as ambiguous, which broke several bots. This
commit explicitly defines DenseMapPair's constructos to work around the issue.
https://reviews.llvm.org/D53726
llvm-svn: 345411
constructor for DenseMap (DenseSet already had an initializer_list constructor).
These changes make it easier to migrate existing code that uses std::map and
std::set (which support initializer_list construction and equality comparison)
to DenseMap and DenseSet.
llvm-svn: 344522
llvm::detail is not the only namespace named detail. So if
someone has done a `using namespace llvm::support`, for example,
this will fail with an ambiguous namespace name. Granted
people generally shouldn't be using large namespaces like that,
but it's common at local function scopes.
llvm-svn: 344216
This creates ODR violations if the function is called from another inline
function in a header and also creates binary bloat from duplicate definitions.
llvm-svn: 316471
POD-like and we can just splat the empty key across memory.
Sadly we can't optimize the normal loop well enough because we can't
turn the conditional store into an unconditional store according to the
memory model.
This loop actually showed up in a profile of code that was calling clear
as a serious source of time. =[
llvm-svn: 310189
Summary:
Similar to SmallPtrSet, this makes find and count work with both const
referneces and const pointers.
Reviewers: dblaikie
Subscribers: llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D30713
llvm-svn: 297424
into CRTP base classes.
This can sometimes happen and not cause an immediate failure when the
derived class is, itself, a template. You can end up essentially calling
methods on the wrong derived type but a type where many things will
appear to "work".
To fail fast and with a clear error message we can use a static_assert,
but we have to stash that static_assert inside a method body or nested
type that won't need to be completed while building the base class. I've
tried to pick a reasonably small number of places that seemed like
reliably places for this to be instantiated.
llvm-svn: 294271
Summary:
If you try to instantiate it with a non-power-of-two buckets, DenseMap
will assert at runtime (!) if we ever outgrow our inline storage.
I believe using a constexpr function inside of a static_assert is safe
now that we've unsupported MSVC 2013 and GCC < 4.8.
Reviewers: bkramer, qcolombet, escha
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25900
llvm-svn: 284985
This provides an elegant pattern to solve the "construct if not in map
already" problem we have many times in LLVM. Without try_emplace we
either have to rely on a sentinel value (nullptr) or do two lookups.
llvm-svn: 276277
Summary:
Just running the loop in the unittests for a few more iterations
(till 48) exhibit that the condition on the limit was not handled
properly in r263522.
Rewrite the test to use a class to count move/copies that happens
when inserting into the map.
Also take the opportunity to refactor the logic to compute the
number of buckets required for a given number of entries in the map.
Use this when constructing a DenseMap with a desired size given to
the constructor (and add a tests for this).
Reviewers: dblaikie
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D18345
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 264384
In some places, like InstCombine, we resize a DenseMap to fit the elements
we intend to put in it, then insert those elements (to avoid continual
reallocations as it grows). But .resize(foo) doesn't actually do what
people think; it resizes to foo buckets (which is really an
implementation detail the user of DenseMap probably shouldn't care about),
not the space required to fit foo elements. DenseMap grows if 3/4 of its
buckets are full, so this actually causes one forced reallocation every
time instead of avoiding a reallocation.
This patch makes .resize(foo) do the intuitive thing: it grows to the size
necessary to fit foo elements without new allocations.
Also include a test to verify that .resize() actually does what we think it
does.
llvm-svn: 263522
Just like the existing find_as() method, the new insert_as() accepts
an extra parameter which is used as a key to find the bucket in the
map.
When creating a Constant, we want to check the map before actually
creating the object. In this case we have to perform two queries to
the map, and this extra parameter can save recomputing the hash value
for the second query.
This is a reapply of r260458, that was reverted because it was
suspected to be the cause of instability of an internal bot, but
wasn't confirmed.
Differential Revision: http://reviews.llvm.org/D16268
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 262812
This reverts commit r260458.
It was backported on an internal branch and broke stage2 build. Since
this can lead to weird random crash I'm reverting upstream as well
while investigating.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 260605
Summary:
Just like the existing find_as() method, the new insert_as() accepts
an extra parameter which is used as a key to find the bucket in the
map.
When creating a Constant, we want to check the map before actually
creating the object. In this case we have to perform two queries to
the map, and this extra parameter can save recomputing the hash value
for the second query.
Reviewers: dexonsmith, chandlerc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16268
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 260458
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
