* Fix non-null violation in strstream.cpp
Overflow was calling memcpy with a null parameter and a size of 0.
* Fix std/atomics/atomics.flag/ tests:
a.test_and_set() was reading from an uninitialized atomic, but wasn't
using the value. The tests now clear the flag before performing the
first test_and_set. This allows UBSAN to test that clear doesn't read
an invalid value.
* Fix std/experimental/algorithms/alg.random.sample/sample.pass.cpp
The tests were dereferencing a past-the-end pointer to an array so that
they could do pointer arithmetic with it. Instead of dereference the iterator
I changed the tests to use the special 'base()' test iterator method.
* Add -fno-sanitize=float-divide-by-zero to suppress division by zero UBSAN diagnostics.
The tests that cause float division by zero are explicitly aware that they
are doing that. Since this is well defined for IEEE floats suppress the warnings
for now.
llvm-svn: 273107
Summary:
Replace non-Standard "atomic_flag f(false);" with Standard "atomic_flag f;" in clear tests.
Although the value of 'f' is unspecified it shouldn't matter because these tests always call `f.test_and_set()` without checking the result, so the initial state shouldn't matter.
The test init03.pass.cpp is explicitly testing this non-Standard extension; It has been moved into the `test/libcxx` directory.
Reviewers: mclow.lists, STL_MSFT
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D19758
llvm-svn: 268355
Summary:
After putting this question up on cfe-dev I have decided that it would be best to allow the use of `<atomic>` in C++03. Although static initialization is a concern the syntax required to get it is C++11 only. Meaning that C++11 constant static initialization cannot silently break in C++03, it will always cause a syntax error. Furthermore `ATOMIC_VAR_INIT` and `ATOMIC_FLAG_INIT` remain defined in C++03 even though they cannot be used because C++03 usages will cause better error messages.
The main change in this patch is to replace `__has_feature(cxx_atomic)`, which only returns true when C++ >= 11, to `__has_extension(c_atomic)` which returns true whenever clang supports the required atomic builtins.
This patch adds the following macros:
* `_LIBCPP_HAS_C_ATOMIC_IMP` - Defined on clang versions which provide the C `_Atomic` keyword.
* `_LIBCPP_HAS_GCC_ATOMIC_IMP` - Defined on GCC > 4.7. We must use the fallback atomic implementation.
* `_LIBCPP_HAS_NO_ATOMIC_HEADER` - Defined when it is not safe to include `<atomic>`.
`_LIBCPP_HAS_C_ATOMIC_IMP` and `_LIBCPP_HAS_GCC_ATOMIC_IMP` are mutually exclusive, only one should be defined. If neither is defined then `<atomic>` is not implemented and including `<atomic>` will issue an error.
Reviewers: chandlerc, jroelofs, mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11555
llvm-svn: 245463
Eric Fiselier