Summary:
D44883 extends -Wself-assign to also work on C++ classes.
In it's current state (as suggested by @rjmccall), it is not under it's own sub-group.
Since that diag is enabled by `-Wall`, stage2 testing showed that:
* It does not fire on any llvm code
* It does fire for these 3 unittests
* It does fire for libc++ tests
This diff simply silences those new warnings in llvm's unittests.
A similar diff will be needed for libcxx. (`libcxx/test/std/language.support/support.types/byteops/`, maybe something else)
Since i don't think we want to repeat rL322901, let's talk about it.
I've subscribed everyone who i think might be interested...
There are several ways forward:
* Not extend -Wself-assign, close D44883. Not very productive outcome i'd say.
* Keep D44883 in it's current state.
Unless your custom overloaded operators do something unusual for when self-assigning,
the warning is no less of a false-positive than the current -Wself-assign.
Except for tests of course, there you'd want to silence it. The current suggestion is:
```
S a;
a = (S &)a;
```
* Split the diagnostic in two - `-Wself-assign-builtin` (i.e. what is `-Wself-assign` in trunk),
and `-Wself-assign-overloaded` - the new part in D44883.
Since, as i said, i'm not really sure why it would be less of a error than the current `-Wself-assign`,
both would still be in `-Wall`. That way one could simply pass `-Wno-self-assign-overloaded` for all the tests.
Pretty simple to do, and will surely work.
* Split the diagnostic in two - `-Wself-assign-trivial`, and `-Wself-assign-nontrivial`.
The choice of which diag to emit would depend on trivial-ness of that particular operator.
The current `-Wself-assign` would be `-Wself-assign-trivial`.
https://godbolt.org/g/gwDASe - `A`, `B` and `C` case would be treated as trivial, and `D`, `E` and `F` as non-trivial.
Will be the most complicated to implement.
Thoughts?
Reviewers: aaron.ballman, rsmith, rtrieu, rjmccall, dblaikie, atrick, gottesmm
Reviewed By: dblaikie
Subscribers: lebedev.ri, phosek, vsk, rnk, thakis, sammccall, mclow.lists, llvm-commits, rjmccall
Differential Revision: https://reviews.llvm.org/D45082
llvm-svn: 329491
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:
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
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
A DenseMap doesn't store the hashes, so it needs to recompute them when
the table is resized.
In some applications the hashing cost is noticeable. That is the case
for example in lld for symbol names (StringRef).
This patch adds a templated structure that can wraps any value that can
go in a DenseMap and caches the hash.
llvm-svn: 266981
This makes us no longer relying on move-construction elision by the compiler.
Suggested by D. Blaikie.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 264475
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
This complements CopyConstructorNotSmallTest. If we are testing the copy
constructor in such a way, we should also probably test assignment in the same
way.
llvm-svn: 251736
While often you want to use something specialized like StringMap, when
the strings already have persistent storage a normal densemap over them
can be more efficient.
This can't go into StringRef.h because of really obnoxious header chains
from the hashing code to the endian detection code to CPU feature
detection code to StringMap.
llvm-svn: 240528
Accidentally committed a few more of these cleanup changes than
intended. Still breaking these out & tidying them up.
This reverts commit r231135.
llvm-svn: 231136
There doesn't seem to be any need to assert that iterator assignment is
between iterators over the same node - if you want to reuse an iterator
variable to iterate another node, that's perfectly acceptable. Just
don't mix comparisons between iterators into disjoint sequences, as
usual.
llvm-svn: 231135
In theory, Clang should figure out how to parse this correctly without
typename, but since this is the last TU that Clang falls back on in the
self-host, I'm going to compromise and check for __clang__.
And now Clang can self-host on -win32 without fallback! The 'check' and
'check-clang' targets both pass.
llvm-svn: 201358
SmallDenseMap::swap.
First, make it parse cleanly. Yay for uninstantiated methods.
Second, make the inline-buckets case work correctly. This is way
trickier than it should be due to the uninitialized values in empty and
tombstone buckets.
Finally fix a few typos that caused construction/destruction mismatches
in the counting unittest.
llvm-svn: 158641
destruction and fix a bug in SmallDenseMap they caught.
This is kind of a poor-man's version of the testing that just adds the
addresses to a set on construction and removes them on destruction. We
check that double construction and double destruction don't occur.
Amusingly enough, this is enough to catch a lot of SmallDenseMap issues
because we spend a lot of time with fixed stable addresses in the inline
buffer.
The SmallDenseMap bug fix included makes grow() not double-destroy in
some cases. It also fixes a FIXME there, the code was pretty crappy. We
now don't have any wasted initialization, but we do move the entries in
inline bucket array an extra time. It's probably a better tradeoff, and
is much easier to get correct.
llvm-svn: 158639
implementation.
This type includes an inline bucket array which is used initially. Once
it is exceeded, an array of 64 buckets is allocated on the heap. The
bucket count grows from there as needed. Some highlights of this
implementation:
- The inline buffer is very carefully aligned, and so supports types
with alignment constraints.
- It works hard to avoid aliasing issues.
- Supports types with non-trivial constructors, destructors, copy
constructions, etc. It works reasonably hard to minimize copies and
unnecessary initialization. The most common initialization is to set
keys to the empty key, and so that should be fast if at all possible.
This class has a performance / space trade-off. It tries to optimize for
relatively small maps, and so packs the inline bucket array densely into
the object. It will be marginally slower than a normal DenseMap in a few
use patterns, so it isn't appropriate everywhere.
The unit tests for DenseMap have been generalized a bit to support
running over different map implementations in addition to different
key/value types. They've then been automatically extended to cover the
new container through the magic of GoogleTest's typed tests.
All of this is still a bit rough though. I'm going to be cleaning up
some aspects of the implementation, documenting things better, and
adding tests which include non-trivial types. As soon as I'm comfortable
with the correctness, I plan to switch existing users of SmallMap over
to this class as it is already more correct w.r.t. construction and
destruction of objects iin the map.
Thanks to Benjamin Kramer for all the reviews of this and the lead-up
patches. That said, more review on this would really be appreciated. As
I've noted a few times, I'm quite surprised how hard it is to get the
semantics for a hashtable-based map container with a small buffer
optimization correct. =]
llvm-svn: 158638
of typename. GCC and Clang were fine with this, but MSVC won't accept
it. Fortunately, it also doesn't need it. Yuck.
Thanks to Nakamura for pointing this out in IRC.
llvm-svn: 158593
These were already trying to be type parameterized over different
key/value pairs. I've realized this goal using GoogleTest's typed test
functionality. This allows us to easily replicate the tests across
different key/value combinations and soon different mapping templates.
I've fixed a few bugs in the tests and extended them a bit in the
process as many tests were only applying to the int->int mapping.
llvm-svn: 158589
This patch forbids implicit conversion of DenseMap::const_iterator to
DenseMap::iterator which was possible because DenseMapIterator inherited
(publicly) from DenseMapConstIterator. Conversion the other way around is now
allowed as one may expect.
The template DenseMapConstIterator is removed and the template parameter
IsConst which specifies whether the iterator is constant is added to
DenseMapIterator.
Actually IsConst parameter is not necessary since the constness can be
determined from KeyT but this is not relevant to the fix and can be addressed
later.
Patch by Victor Zverovich!
llvm-svn: 86636
* Added the first LLVM unittest -- DenseMap.
* Updated mkpatch utility to include llvm/unittests dir
* Added top-level target "unittests" to run all unittests
llvm-svn: 61541
Roman Lebedev