I have upcoming changes that modify how deque handles spare blocks.
This cleanup is intended to make those changes easier to review
and understand. This patch should have NFC.
llvm-svn: 367631
Previously these types rehashed to a table of 193 elements
upon construction. But this is non-ideal, first because default
constructors should not allocate unless necessary, and second
because 193 is big and can waste a bunch of memory.
This number had previously been chosen to match GCC's implementation.
llvm-svn: 367605
[cpp.predefined]p2:
__STDCPP_THREADS__
Defined, and has the value integer literal 1, if and only if a program
can have more than one thread of execution .
Also define it only if it's not defined already, since it's supposed
to be defined by the compiler.
Also move it from thread to __config (which requires setting it only
if _LIBCPP_HAS_NO_THREADS is not defined).
Part of PR33230. The intent is to eventually make the compiler define
this instead.
llvm-svn: 367316
The test configuration contained a bug where we only raised
the __config_site commands to the command line if modules were
enabled for all of the libc++ tests. However there are special
modules-only tests, and these tests weren't getting the correct
defines.
This patch corrects that issue.
llvm-svn: 367267
The optimizer is petulant and temperamental. In this case LLVM failed to lower
the the "insert at end" loop used by`vector<unsigned char>` to a `memset` despite
`memset` being substantially faster over a range of bytes.
LLVM has the ability to lower loops to `memset` whet appropriate, but the
odd nature of libc++'s loops prevented the optimization from taking places.
This patch addresses the issue by rewriting the loops from the form
`do [ ... --__n; } while (__n > 0);` to instead use a for loop over a pointer
range (For example: `for (auto *__i = ...; __i < __e; ++__i)`).
This patch also rewrites the asan annotations to unposion all additional memory
at the start of the loop instead of once per iterations. This could potentially
permit false negatives where the constructor of element N attempts to access
element N + 1 during its construction.
The before and after results for the `BM_ConstructSize/vector_byte/5140480_mean`
benchmark (run 5 times) are:
--------------------------------------------------------------------------------------------
Benchmark Time CPU Iterations
--------------------------------------------------------------------------------------------
Before
------
BM_ConstructSize/vector_byte/5140480_mean 12530140 ns 12469693 ns N/A
BM_ConstructSize/vector_byte/5140480_median 12512818 ns 12445571 ns N/A
BM_ConstructSize/vector_byte/5140480_stddev 106224 ns 107907 ns 5
-----
After
-----
BM_ConstructSize/vector_byte/5140480_mean 167285 ns 166500 ns N/A
BM_ConstructSize/vector_byte/5140480_median 166749 ns 166069 ns N/A
BM_ConstructSize/vector_byte/5140480_stddev 3242 ns 3184 ns 5
llvm-svn: 367183
Summary:
On AIX psutil can run into problems with permissions to read the process
tree, which causes problems for python timeout tests which need to kill off
a test and it's children.
This patch adds a workaround by invoking shell via subprocess and using a
platform specific option to ps to list all the descendant processes so we can
kill them. We add some checks so lit can tell whether timeout tests are
supported with out exposing whether we are utilizing the psutil
implementation or the alternative.
Reviewers: hubert.reinterpretcast, andusy, davide, delcypher
Reviewed By: delcypher
Subscribers: davide, delcypher, christof, lldb-commits, libcxx-commits, llvm-commits
Tags: #lldb, #libc, #llvm
Differential Revision: https://reviews.llvm.org/D64251
llvm-svn: 366912
This is a cherrypick of D64237 onto llvm/utils/benchmark and
libcxx/utils/google-benchmark.
Differential Revision: https://reviews.llvm.org/D65142
llvm-svn: 366868
The constructors for std::pair and std::tuple have been made conditionally
explicit, however the synopsis in the headers do not reflect that.
llvm-svn: 366735
r362048 added support for ELF dependent libraries, but broke Android
build since Android does not have libpthread. Remove the dependency on
the Android build.
Differential Revision: https://reviews.llvm.org/D65098
llvm-svn: 366734
This issue was detected by ASan in one of our tests. This test manually
invokes basic_filebuf::cloe(). fclose(__h.release() returned a non-zero
exit status, so __file_ wasn't set to 0. Later when basic_filebuf
destructor ran, we would enter the if (__file_) block again leading to
heap-use-after-free error.
The POSIX specification for fclose says that independently of the return
value, fclose closes the underlying file descriptor and any further
access (including another call to fclose()) to the stream results in
undefined behavior. This is exactly what happened in our test case.
To avoid this issue, we have to always set __file_ to 0 independently of
the fclose return value.
Differential Revision: https://reviews.llvm.org/D64979
llvm-svn: 366730
libc++'s lit configuration infers the C++ language dialect when it is
not provided by checking which -std= flags that a compiler supports.
GCC 5 and GCC 6 have a -std=c++17 flag, however, they do not have full
C++17 support. The lit configuration has hardcoded logic that removes
-std=c++1z as an option to test for GCC < 7, but not -std=c++17.
This leads to a bunch of failures when running libc++ tests with GCC 5
or GCC 6. This patch adds -std=c++17 to the list of flags that are
discarded for GCC < 7 by lit's language dialect inference.
Thanks to Bryce Adelstein Lelbach for the patch.
Differential Revision: https://reviews.llvm.org/D62874
llvm-svn: 366700
Some minor versions of AppleClang 9 appear not to fail the test. It's
such a mess that the only sane thing to do is to mark the test as
UNSUPPORTED.
llvm-svn: 366606
This reverts r366593, which caused unforeseen breakage on the build bots.
I'm reverting until the problems have been figured out and fixed.
llvm-svn: 366603
Summary:
This commit allows specifying LIBCXX_ENABLE_PARALLEL_ALGORITHMS when
configuring libc++ in CMake. When that option is enabled, libc++ will
assume that the PSTL can be found somewhere on the CMake module path,
and it will provide the C++17 parallel algorithms based on the PSTL
(that is assumed to be available).
The commit also adds support for running the PSTL tests as part of
the libc++ test suite.
Reviewers: rodgert, EricWF
Subscribers: mgorny, christof, jkorous, dexonsmith, libcxx-commits, mclow.lists, EricWF
Tags: #libc
Differential Revision: https://reviews.llvm.org/D60480
llvm-svn: 366593
Without the link flags, the test always fails on Linux. For some reason,
however, it works on Darwin -- which is why it wasn't caught at first.
llvm-svn: 366579
Summary:
This is effectively a revert of r344616, which was a partial fix for
PR38964 (compilation of <string> with GCC in C++03 mode). However, that
configuration is explicitly not supported anymore and that partial fix
breaks compilation with Clang when per-TU insulation is provided.
PR42676
rdar://52899715
Reviewers: mclow.lists, EricWF
Subscribers: christof, jkorous, dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D64941
llvm-svn: 366567
In r361572, we introduced library support for C++20 destroying delete
and decided to only define the library feature-test macro when the
compiler supports the underlying language feature. This patch reworks
the tests to mirror that.
llvm-svn: 366263
The tests for unordered_set and unordered_multiset were missing UNSUPPORTED
markup for Apple Clang 9.1, which is still being used on some CI bots.
llvm-svn: 366259
In particular, improve the compile time of the overload set builder
that variant uses to determine which alternative to construct.
Instead of having the __overload type construct itself recursively,
this patch uses a flat construction for the overload set.
llvm-svn: 366033
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
Previously we implemented all one trillion tuple-like constructors using
a single generic overload. This worked fairly well, except that it
differed in behavior from the standard version because it didn't
consider both T&& and T const&. This was observable for certain
types.
This patch addresses that issue by splitting the generic constructor
in two. We now provide both T&& and T const& versions of the
tuple-like constructors (sort of).
llvm-svn: 365973
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
The buildbots were changed to pass -DLIBCXX_CXX_ABI=libcxxabi, but
they don't provide an include path for the library, so cxxabi.h is
never found while building libc++.
This is a temporary change until the buildbots are updated or until
D63883 lands in a form that unbreaks the bots
llvm-svn: 365847
When assigning an initializer list into set/map, libc++ would
leak memory if the initializer list contained equivalent keys
because we failed to check if the insertion was successful.
llvm-svn: 365840
Eric Fiselier