Commit Graph

108 Commits

Author SHA1 Message Date
Arthur O'Dwyer 16bf43398a [libc++] Comma-operator-proof a lot of algorithm/container code.
Detected by evil-izing the widely used `MoveOnly` testing type.
I had to patch some tests that were themselves using its comma operator,
but I think that's a worthwhile cost in order to catch more places
in our headers that needed comma-proofing.

The trick here is that even `++ptr, SomeClass()` can find a comma operator
by ADL, if `ptr` is of type `Evil*`. (A comma between two operands
of non-class-or-enum type is always treated as the built-in
comma, without ADL. But if either operand is class-or-enum, then
ADL happens for _both_ operands' types.)

Differential Revision: https://reviews.llvm.org/D109414
2021-09-08 13:34:01 -04:00
Louis Dionne 2e4755ff60 [libc++] Fix a few warnings in system headers with GCC
This isn't fixing all of them, but at least it's making some progress.

Differential Revision: https://reviews.llvm.org/D106283
2021-07-27 20:09:01 -04:00
Arthur O'Dwyer bfbd73f87d [libc++] Alphabetize and include-what-you-use. NFCI.
Differential Revision: https://reviews.llvm.org/D102781
2021-05-29 19:54:48 -04:00
Amy Huang 7c2f58278e Apply [[standalone_debug]] to some types in the STL.
Add this attribute to some types to ensure that they have
debug info.
The debug info for these classes are required for debuggers to display
some STL types. With constructor homing (a new debug info optimization)
their debug info isn't emitted because their constructors are never
called.

The list of types with the attribute added are __hash_value_type,
__value_type, __tree_node_base, __tree_node, __hash_node, __list_node,
and __forward_list_node.

Differential Revision: https://reviews.llvm.org/D98750
2021-05-18 17:01:07 -07:00
Kristina Bessonova 8a86787847 [libcxx] NFC. Fix misprint unodered -> unordered
Differential Revision: https://reviews.llvm.org/D102354
2021-05-13 09:57:29 +02:00
Kristina Bessonova 96100f1508 [libcxx] NFC. Correct wordings of _LIBCPP_ASSERT debug messages
Differential Revision: https://reviews.llvm.org/D102195
2021-05-12 13:49:57 +02:00
Louis Dionne 4cd6ca102a [libc++] NFC: Normalize `#endif //` comment indentation 2021-04-20 12:03:32 -04:00
Arthur O'Dwyer b6f1917415 [libc++] Fix some one-off typos in comments. NFCI. 2020-12-14 09:54:58 -05:00
Arthur O'Dwyer 3696227c10 [libc++] ADL-proof by adding _VSTD:: qualifications to memmove etc.
Generally these calls aren't vulnerable to ADL because they involve only
primitive types. The ones in <list> and <vector> drag in namespace std
but that's OK; the ones in <fstream> and <strstream> are vulnerable
iff `CharT` is an enum type, which seems far-fetched.
But absolutely zero of them *need* ADL to happen; so in my opinion
they should all be consistently qualified, just like calls to any
other (non-user-customizable) functions in namespace std.

Also: Include <cstring> and <cwchar> in <__string>.
We seemed to be getting lucky that <memory> included <iterator>
included <iosfwd> included <wchar.h>. That gave us the
global-namespace `wmemmove`, but not `_VSTD::wmemmove`.
This is now fixed.

I didn't touch these headers:
<ext/__hash> uses strlen, safely
<support/ibm/locale_mgmt_aix.h> uses memcpy, safely
<string.h> uses memchr and strchr, safely
<wchar.h> uses wcschr, safely
<__bsd_locale_fallbacks.h> uses wcsnrtombs, safely

Differential Revision: https://reviews.llvm.org/D93061
2020-12-10 22:03:12 -05:00
Arthur O'Dwyer d586f92c94 [libc++] Consistently replace `std::` qualification with `_VSTD::` or nothing. NFCI.
I used a lot of `git grep` to find places where `std::` was being used
outside of comments and assert-messages. There were three outcomes:

- Qualified function calls, e.g. `std::move` becomes `_VSTD::move`.
    This is the most common case.

- Typenames that don't need qualification, e.g. `std::allocator` becomes `allocator`.
    Leaving these as `_VSTD::allocator` would also be fine, but I decided
    that removing the qualification is more consistent with existing practice.

- Names that specifically need un-versioned `std::` qualification,
    or that I wasn't sure about. For example, I didn't touch any code in
    <atomic>, <math.h>, <new>, or any ext/ or experimental/ headers;
    and I didn't touch any instances of `std::type_info`.

In some deduction guides, we were accidentally using `class Alloc = typename std::allocator<T>`,
despite `std::allocator<T>`'s type-ness not being template-dependent.
Because `std::allocator` is a qualified name, this did parse as we intended;
but what we meant was simply `class Alloc = allocator<T>`.

Differential Revision: https://reviews.llvm.org/D92250
2020-12-01 22:13:39 -05:00
Arthur O'Dwyer 6e965df605 Revert "Revert "[libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls.""
This reverts commit 620adacf87.

Fix: unsupport C++03 for the new test, define helpers before __swap_allocator

(1) Add _VSTD:: qualification to __swap_allocator.

(2) Add _VSTD:: qualification consistently to __to_address.

(3) Add some more missing _VSTD:: to <vector>, with a regression test.
This part is cleanup after d9a4f936d0.

Note that a vector whose allocator actually runs afoul of any of these ADL calls will
likely also run afoul of simple things like `v1 == v2` (which is also an ADL call).
But, still, libc++ should be consistent in qualifying function calls wherever possible.

Relevant blog post: https://quuxplusone.github.io/blog/2019/09/26/uglification-doesnt-stop-adl/

Differential Revision: https://reviews.llvm.org/D91708
2020-11-20 20:59:18 -05:00
Mikhail Goncharov 620adacf87 Revert "[libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls."
This reverts commit 40267cc989.

Build fails, e.g. http://lab.llvm.org:8011/#/builders/23/builds/108
2020-11-19 15:36:49 +01:00
Arthur O'Dwyer 40267cc989 [libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls.
(1) Add _VSTD:: qualification to __swap_allocator.

(2) Add _VSTD:: qualification consistently to __to_address.

(3) Add some more missing _VSTD:: to <vector>, with a regression test.
This part is cleanup after d9a4f936d0.

Note that a vector whose allocator actually runs afoul of any of these ADL calls will
likely also run afoul of simple things like `v1 == v2` (which is also an ADL call).
But, still, libc++ should be consistent in qualifying function calls wherever possible.

Relevant blog post: https://quuxplusone.github.io/blog/2019/09/26/uglification-doesnt-stop-adl/

Differential Revision: https://reviews.llvm.org/D91708
2020-11-19 09:19:16 -05:00
Louis Dionne 12805513a6 [libc++] Remove some workarounds for C++03
We don't support any compiler that doesn't support variadics and rvalue
references in C++03 mode, so these workarounds can be dropped. There's
still *a lot* of cruft related to these workarounds, but I try to tackle
a bit of it here and there.
2020-10-09 12:35:13 -04:00
Louis Dionne 870827f652 [libc++] NFCI: Remove the _LIBCPP_DEBUG_MODE helper macro
It was used inconsistently and the name was pretty confusing, so we might
as well use `#if _LIBCPP_DEBUG_LEVEL == 2` consistently everywhere.
2020-10-02 15:11:23 -04:00
Louis Dionne 31e820378b [libc++] NFCI: Simplify macro definitions for the debug mode
The debug mode always had three possibilities:
- _LIBCPP_DEBUG is undefined => no assertions
- _LIBCPP_DEBUG == 0         => some assertions
- _LIBCPP_DEBUG == 1         => some assertions + iterator checks

This was documented that way, however the code did not make this clear
at all. The discrepancy between _LIBCPP_DEBUG and _LIBCPP_DEBUG_LEVEL
was especially confusing. I reworked how the various macros are defined
without changing anything else to make the code clearer.
2020-10-02 15:11:23 -04:00
Louis Dionne 8d4860aa9e [libc++] Remove workarounds for missing rvalue references
We don't support GCC in C++03 mode, and Clang provides rvalue references
even in C++03 mode. So there's effectively no supported compiler that
doesn't support rvalue references.

Differential Revision: https://reviews.llvm.org/D84943
2020-08-12 12:02:28 -04:00
Eric Fiselier 549545b64a [libc++] Rework compressed pair constructors.
This patch de-duplicates most compressed pair constructors
to use the same code in C++11 and C++03.

Part of doing that is deleting the "__second_tag()" and replacing
it with a "__value_init_tag()" which has the same effect, but
allows for the removal of the special "one-arg" first element
constructor.

This patch is intended to have no semantic change.
2019-12-16 18:38:58 -05:00
Eric Fiselier f97936fabd [libc++] Cleanup and enable multiple warnings.
Too many warnings are being disabled too quickly. Warnings are
important to keeping libc++ correct. This patch re-enables two
warnings: -Wconstant-evaluated and -Wdeprecated-copy.

In future, all warnings disabled for the test suite should require
an attached bug. The bug should state the plan for re-enabling that
warning, or a strong case why it should remain disabled.
2019-12-12 21:09:08 -05:00
Marshall Clow f3b851f0b8 Reorganize the 'bit' header to make most of the facilities available for internal use pre-C++20. NFC for external users
llvm-svn: 365854
2019-07-12 01:01:55 +00:00
Eric Fiselier 6886f1e39b Avoid name conflict with kernel headers
llvm-svn: 359080
2019-04-24 09:43:44 +00:00
Louis Dionne 7c142fcc06 [libc++] Make sure we don't eagerly diagnose non-const comparators for containers of incomplete types
Summary:
In r348529, I improved the library-defined diagnostic for using containers
with a non-const comparator/hasher. However, the check is now performed
too early, which leads to the diagnostic being emitted in cases where it
shouldn't. See PR41360 for details.

This patch moves the diagnostic to the destructor of the containers, which
means that the diagnostic will only be emitted when the container is instantiated
at a point where the comparator and the key/value are required to be complete.
We still retain better diagnostics than before r348529, because the diagnostics
are performed in the containers themselves instead of __tree and __hash_table.

As a drive-by fix, I improved the diagnostic to mention that we can't find
a _viable_ const call operator, as suggested by EricWF in PR41360.

Reviewers: EricWF, mclow.lists

Subscribers: christof, jkorous, dexonsmith, libcxx-commits, zoecarver

Tags: #libc

Differential Revision: https://reviews.llvm.org/D60540

llvm-svn: 358189
2019-04-11 16:14:56 +00:00
Eric Fiselier 61b302f94f Remove exception throwing debug mode handler support.
Summary:
The reason libc++ implemented a throwing debug mode handler was for ease of testing. Specifically,
I thought that if a debug violation aborted, we could only test one violation per file. This made
it impossible to test debug mode. Which throwing behavior we could test more!

However, the throwing approach didn't work either, since there are debug violations underneath noexcept
functions. This lead to the introduction of `_NOEXCEPT_DEBUG`, which was only noexcept when debug
mode was off.

Having thought more and having grown wiser, `_NOEXCEPT_DEBUG` was a horrible decision. It was
viral, it didn't cover all the cases it needed to, and it was observable to the user -- at worst
changing the behavior of their program.

  This patch removes the throwing debug handler, and rewrites the debug tests using 'fork-ing' style
  death tests.

Reviewers: mclow.lists, ldionne, thomasanderson

Reviewed By: ldionne

Subscribers: christof, arphaman, libcxx-commits, #libc

Differential Revision: https://reviews.llvm.org/D59166

llvm-svn: 356417
2019-03-18 21:50:12 +00:00
Marshall Clow 954966c1af Add UBSAN annotation to __hash_table::rehash; we don't do anything wrong, but UBSAN's checker flags it as suspicious. See PR38606. NFC
llvm-svn: 353448
2019-02-07 18:53:58 +00:00
Chandler Carruth 57b08b0944 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
2019-01-19 10:56:40 +00:00
Louis Dionne 3560fbf304 [libc++] Improve diagnostics for non-const comparators and hashers in associative containers
Summary:
When providing a non-const-callable comparator in a map or set, the
warning diagnostic does not include the point of instantiation of
the container that triggered the warning, which makes it difficult
to track down the problem. This commit improves the diagnostic by
placing it directly in the body of the associative container.

The same change is applied to unordered associative containers, which
had a similar problem.

Finally, this commit cleans up the forward declarations of several
map and unordered_map helpers, which are not needed anymore.

<rdar://problem/41370747>

Reviewers: EricWF, mclow.lists

Subscribers: christof, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D48955

llvm-svn: 348529
2018-12-06 21:46:17 +00:00
Erik Pilkington 5c4e07ae5c Second half of C++17's splicing maps and sets
This commit adds a merge member function to all the map and set containers,
which splices nodes from the source container. This completes support for
P0083r3.

Differential revision: https://reviews.llvm.org/D48896

llvm-svn: 345744
2018-10-31 17:31:35 +00:00
Erik Pilkington b0386a515b First half of C++17's splicing maps and sets
This commit adds a node handle type, (located in __node_handle), and adds
extract() and insert() members to all map and set types, as well as their
implementations in __tree and __hash_table.

The second half of this feature is adding merge() members, which splice nodes
in bulk from one container into another. This will be committed in a follow-up.

Differential revision: https://reviews.llvm.org/D46845

llvm-svn: 338472
2018-08-01 01:33:38 +00:00
Erik Pilkington f52318b47b Fix a strict aliasing violation in map and unordered_map.
These containers type-punned between pair<K, V> and pair<const K, V> as an
optimization. This commit instead provides access to the pair via a pair of
references that assign through to the underlying object. It's still undefined to
mutate a const object, but clang doesn't optimize on this for data members, so
this should be safe.

Differential revision: https://reviews.llvm.org/D47607

llvm-svn: 333948
2018-06-04 20:38:23 +00:00
Dan Albert 553b09b515 Revert "Make rehash(0) work with ubsan's unsigned-integer-overflow."
Seems to have broken some tests since I first wrote this a while
back. Will reland after checking what went wrong with the tests.

This reverts commit 7023194c8d11a081fd01ed25308b3d60193c6a06.

llvm-svn: 322039
2018-01-08 22:57:12 +00:00
Dan Albert 0802327a39 Make rehash(0) work with ubsan's unsigned-integer-overflow.
Reviewers: mclow.lists, EricWF

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D40743

llvm-svn: 322031
2018-01-08 21:49:12 +00:00
Marshall Clow 87af646034 Fix some undefined behavior in __hash_table. Thanks to vsk for the report and the patch. Reviewed as https://reviews.llvm.org/D33588.
llvm-svn: 304617
2017-06-03 00:08:32 +00:00
Eric Fiselier a016efb1dc [Libc++] Use #pragma push_macro/pop_macro to better handle min/max on Windows
Summary:
This patch improves how libc++ handles min/max macros within the headers. Previously libc++ would undef them and emit a warning.
This patch changes libc++ to use `#pragma push_macro`  to save the macro before undefining it, and `#pragma pop_macro` to restore the macros and the end of the header.

Reviewers: mclow.lists, bcraig, compnerd, EricWF

Reviewed By: EricWF

Subscribers: cfe-commits, krytarowski

Differential Revision: https://reviews.llvm.org/D33080

llvm-svn: 304357
2017-05-31 22:07:49 +00:00
Eric Fiselier afa7a957bd Cleanup remaining _LIBCPP_HAS_NO_<c++11-feature> usages in container headers
llvm-svn: 300643
2017-04-19 01:23:04 +00:00
Eric Fiselier c88580c400 [libcxx] Fix __compressed_pair so it doesn't copy the argument multiple times, and add constexpr.
Summary:
__compressed_pair takes and passes it's constructor arguments by value. This causes arguments to be moved 3 times instead of once. This patch addresses that issue and fixes `constexpr` on the constructors.

I would rather have this fix than D27564, and I'm fairly confident it's not ABI breaking but I'm not 100% sure.

I prefer this solution because it removes a lot of code and makes the implementation *much* smaller.

Reviewers: mclow.lists, K-ballo

Reviewed By: K-ballo

Subscribers: K-ballo, cfe-commits

Differential Revision: https://reviews.llvm.org/D27565

llvm-svn: 300140
2017-04-12 23:45:53 +00:00
Eric Fiselier bd6a2d8505 Fix hash requirements check in __hash_table.
r296565 attempted to add better diagnostics when an unordered container
is instantiated with a hash that doesn't meet the Hash requirements.

However I mistakenly checked the wrong set of requirements. Specifically
it checked if the hash met the requirements for specializations of
std::hash. However these requirements are stricter than the generic
Hash requirements.

This patch fixes the assertions to only check the Hash requirements.

llvm-svn: 296919
2017-03-03 22:35:58 +00:00
Eric Fiselier acb21581d7 Improve diagnostics when an invalid hash is used in an unordered container.
This patch adds a static assertion that the specified hash meets
the requirements of an enabled hash, and it ensures that the static
assertion is evaluated before __compressed_pair is instantiated.
That way the static assertion diagnostic is emitted first.

llvm-svn: 296565
2017-03-01 02:02:28 +00:00
Eric Fiselier 04333f9bda Diagnose non-const-callable hash functions and comparators
llvm-svn: 291969
2017-01-13 22:42:53 +00:00
Eric Fiselier cd71f447b7 [libc++] Tolerate presence of __deallocate macro
Summary:
On Windows the identifier `__deallocate` is defined as a macro by one of the Windows system headers. Previously libc++ worked around this by `#undef __deallocate` and generating a warning. However this causes the WIN32 version of `__threading_support` to always generate a warning on Windows. This is not OK.

This patch renames all usages of `__deallocate` internally as to not conflict with the macro.

Reviewers: mclow.lists, majnemer, rnk, rsmith, smeenai, compnerd

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D28426

llvm-svn: 291332
2017-01-07 03:01:24 +00:00
Eric Fiselier e2f2d1edef [NFC] Rename _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS
The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).

This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.

llvm-svn: 291035
2017-01-04 23:56:00 +00:00
Eric Fiselier 780b51df1d Add tests for unordered container tests and std::string
llvm-svn: 290655
2016-12-28 05:53:01 +00:00
Eric Fiselier 341c9dd9c4 Fix __hash_table::max_size() on 32 bit systems
llvm-svn: 287749
2016-11-23 09:16:12 +00:00
Eric Fiselier 55b31b4e69 [libcxx] Fix max_size() across all containers
Summary: The `max_size()` method of containers should respect both the allocator's reported `max_size` and the range of the `difference_type`. This patch makes all containers choose the smallest of those two values.

Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D26885

llvm-svn: 287729
2016-11-23 01:18:56 +00:00
Eric Fiselier 4271d0148a Fix missing _LIBCPP_INLINE_VISIBILITY macro on C++03 specific __hash_table function
llvm-svn: 282349
2016-09-25 04:05:46 +00:00
Eric Fiselier 1a06fe5f7e Skip chash computation in insert/emplace if the unconstrained hash matches.
llvm-svn: 276549
2016-07-24 06:22:25 +00:00
Eric Fiselier 40492ba417 Fix undefined behavior in __hash_table
Summary:
This patch attempts to fix the undefined behavior in __hash_table by changing the node pointer types used throughout. The pointer types are changed for raw pointers in the current ABI and for fancy pointers in ABI V2 (since the fancy pointer types may not be ABI compatible).

The UB in `__hash_table` arises because tree downcasts the embedded end node and then deferences that pointer. Currently there are 2 node types in __hash_table:

* `__hash_node_base` which contains the `__next_` pointer.
* `__hash_node` which contains `__hash_` and `__value_`.

Currently the bucket list, iterators, and `__next_` pointers store pointers to `__hash_node` even though they all need to store `__hash_node_base` pointers.
This patch makes that change by introducing a `__next_pointer` typedef which is a pointer to `__hash_node` in the current ABI and `__hash_node_base` afterwards.

One notable change is to the type of `__bucket_list` which used to be defined as `unique_ptr<__node_pointer[], ...>` and is now `unique_ptr<__next_pointer[], ...>` meaning that we now allocate and deallocate different types using a different allocator. I'm going to give this part of the change more thought since it may introduce compatibility issues.

This change is similar to D20786.



Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D20787

llvm-svn: 276533
2016-07-23 20:36:55 +00:00
Eric Fiselier 6a411472e3 Check for unconstrained hash equality before constrained hash equality.
This patch implements a simple optimization in __hash_table::find. When iterating
the found bucket we only constrain the bucket elements hash if it doesn't
already match the unconstrained hash of the specified key. This prevent
the performance of an expensive modulo operation.

Since the bucket element almost always matches the key, especially when the
load factor is low, this optimization has large performance impacts. For
a unordered_set<int> of random integers this patch improves the performance of
'find(...)' by 40%.

llvm-svn: 275734
2016-07-17 22:04:57 +00:00
Eric Fiselier 118cb4180f Don't compute modulus of hash if it is smaller than the bucket count.
This cleans up a previous optimization attempt in hash, and results in
additional performance improvements over that previous attempt. Additionally
this new optimization does not hinder the power of 2 bucket count optimization.

llvm-svn: 275114
2016-07-11 22:02:02 +00:00
Kwasi Mensah 318d35a7bc [libc++] Check hash before calling __hash_table key_eq function
Summary: The current implementations of __hash_table::find used by std::unordered_set/unordered_map call key_eq on each key that lands in the same bucket as the key you're looking for. However, since equal objects mush hash to the same value, you can short-circuit the possibly expensive call to key_eq by checking the hashes first.

Reviewers: EricWF

Subscribers: kmensah, cfe-commits

Differential Revision: http://reviews.llvm.org/D21510

llvm-svn: 274857
2016-07-08 15:34:28 +00:00
Eric Fiselier f977598bb6 Improve performance of unordered_set<uint32_t>::find by 45%. Add benchmarks.
This patch improves the performance of unordered_set's find by 45% when
the value exists within the set. __hash_tables find method
needs to check if it's reached the end of the bucket by constraining the
hash of the current node and checking it against the bucket index. However
constraining the hash is an expensive operations and it can be avoided if the
two unconstrained hashes are equal. This patch applies that optimization.

This patch also adds a top level directory called benchmarks. 'benchmarks/'
is intended to store any/all benchmarks written for the standard library.
Currently nothing is done with files under 'benchmarks/' but I would like
to move towards introducing a formal format and test runner.

llvm-svn: 274423
2016-07-02 05:19:59 +00:00