Libc++ is used as a system library on macOS and iOS (amongst others). In order
for users to be able to compile a binary that is intended to be deployed to an
older version of the platform, clang provides the
availability attribute <https://clang.llvm.org/docs/AttributeReference.html#availability>_
that can be placed on declarations to describe the lifecycle of a symbol in the
library.
See docs/DesignDocs/AvailabilityMarkup.rst for more information.
Differential Revision: https://reviews.llvm.org/D31739
llvm-svn: 302172
This patch overhalls the libc++ test format/configuration in order to fully support modules. By "fully support" I mean get almost all of the tests passing. The main hurdle for doing this is handling tests that `#define _LIBCPP_FOO` macros to test a different configuration. This patch deals with these tests in the following ways:
1. For tests that define single `_LIBCPP_ABI_FOO` macros have been annotated with `// MODULES_DEFINES: _LIBCPP_ABI_FOO`. This allows the test suite to define the macro on the command line so it uses a different set of modules.
2. Tests for libc++'s debug mode (which define custom `_LIBCPP_ASSERT`) are automatically detected by the test suite and are compiled and run with modules disabled.
This patch also cleans up how the `CXXCompiler` helper class handles enabling/disabling language features.
NOTE: This patch uses `LIT` features which were only committed to LLVM today. If this patch breaks running the libc++ tests you probably need to update LLVM.
llvm-svn: 288728
Some of the mutex tests fail on machines with high load. This patch implements
the test directive "// FLAKY_TEST" which allows a test to be run 3 times
before it's considered a failure.
llvm-svn: 280050
Quite a few libcxx tests seem to follow the format:
#if _LIBCPP_STD_VER > X
// Do test.
#else
// Empty test.
#endif
We should instead use the UNSUPPORTED lit directive to exclude the test on
earlier C++ standards. This gives us a more accurate number of test passes
for those standards and avoids unnecessary conflicts with other lit
directives on the same tests.
Reviewers: bcraig, ericwf, mclow.lists
Differential revision: http://reviews.llvm.org/D20730
llvm-svn: 271108
Summary:
The summary of the bug, provided by Stephan T. Lavavej:
In shared_timed_mutex::try_lock_until() (line 195 in 3.6.0), you need to deliver a notification. The scenario is:
* There are N threads holding the shared lock.
* One thread calls try_lock_until() to attempt to acquire the exclusive lock. It sets the "I want to write" bool/bit, then waits for the N readers to drain away.
* K more threads attempt to acquire the shared lock, but they notice that someone said "I want to write", so they block on a condition_variable.
* At least one of the N readers is stubborn and doesn't release the shared lock.
* The wannabe-writer times out, gives up, and unsets the "I want to write" bool/bit.
At this point, a notification (it needs to be notify_all) must be delivered to the condition_variable that the K wannabe-readers are waiting on. Otherwise, they can block forever without waking up.
Reviewers: mclow.lists, jyasskin
Reviewed By: jyasskin
Subscribers: jyasskin, cfe-commits
Differential Revision: http://reviews.llvm.org/D8796
llvm-svn: 233944
Stephan T. Lavavej