[libcxx-commits] [libcxx] 64a9c94 - Revert "[libc++] Build the dylib with C++17 to allow aligned new/delete"
Louis Dionne via libcxx-commits
libcxx-commits at lists.llvm.org
Tue Mar 24 19:54:27 PDT 2020
Author: Louis Dionne
Date: 2020-03-24T22:53:47-04:00
New Revision: 64a9c944fc459475b3eefed423e3b593353c0cca
URL: https://github.com/llvm/llvm-project/commit/64a9c944fc459475b3eefed423e3b593353c0cca
DIFF: https://github.com/llvm/llvm-project/commit/64a9c944fc459475b3eefed423e3b593353c0cca.diff
LOG: Revert "[libc++] Build the dylib with C++17 to allow aligned new/delete"
This reverts commit 1ac403bd145dadfa1004af29bd6c77f871caf42c, which
broke some non-libc++ build bots because they use an ancient CMake.
Added:
Modified:
libcxx/CMakeLists.txt
libcxx/src/barrier.cpp
Removed:
################################################################################
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
index fa194d4bffd9..8bdb24e5fd2a 100644
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -520,10 +520,10 @@ remove_flags(-Wno-pedantic -pedantic-errors -pedantic)
# Required flags ==============================================================
function(cxx_add_basic_build_flags target)
- # Require C++17 for all targets. C++17 is needed to use aligned allocation
- # in the dylib.
+ # Require C++14 for all targets. C++14 is needed to ensure constant
+ # initialization for certain globals (ex global memory resources).
set_target_properties(${target} PROPERTIES
- CXX_STANDARD 17
+ CXX_STANDARD 14
CXX_STANDARD_REQUIRED YES
CXX_EXTENSIONS NO)
diff --git a/libcxx/src/barrier.cpp b/libcxx/src/barrier.cpp
index 9ee476993b81..c5e33cbba3bd 100644
--- a/libcxx/src/barrier.cpp
+++ b/libcxx/src/barrier.cpp
@@ -26,15 +26,21 @@ class __barrier_algorithm_base {
} __tickets[64];
};
- ptr
diff _t& __expected;
- unique_ptr<__state_t[]> __state;
+ ptr
diff _t& __expected;
+ unique_ptr<char[]> __state_allocation;
+ __state_t* __state;
_LIBCPP_HIDDEN
__barrier_algorithm_base(ptr
diff _t& __expected)
: __expected(__expected)
{
size_t const __count = (__expected + 1) >> 1;
- __state = unique_ptr<__state_t[]>(new __state_t[__count]);
+ size_t const __size = sizeof(__state_t) * __count;
+ size_t __allocation_size = __size + alignof(__state_t);
+ __state_allocation = unique_ptr<char[]>(new char[__allocation_size]);
+ void* __allocation = __state_allocation.get();
+ void* const __state_ = align(alignof(__state_t), __size, __allocation, __allocation_size);
+ __state = new (__state_) __barrier_algorithm_base::__state_t[__count];
}
_LIBCPP_HIDDEN
bool __arrive(__barrier_phase_t __old_phase)
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