This is about how we handle static member of a template. Before this commit,
we use internal linkage for the IR thread-local variable, which is inefficient.
With this commit, we will start to follow Itanium C++ ABI.
rdar://problem/23415206
Reviewed by John McCall.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@252814 91177308-0d34-0410-b5e6-96231b3b80d8
OS X TLS has all accesses going through the thread-wrapper function and
gives the backing thread-local variable internal linkage. This means
that thread-wrappers must have WeakAnyLinkage so that references to the
internal thread-local variables do not get propagated to other code.
It also means that translation units which do not provide a definition
for the thread-local variable cannot attempt to emit a thread-wrapper
because the thread wrapper will attempt to reference the backing
variable.
Differential Revision: http://reviews.llvm.org/D4109
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212841 91177308-0d34-0410-b5e6-96231b3b80d8
The backing store of thread local variables is internal for OS X and all
accesses must go through the thread wrapper.
However, individual TUs may have inlined through the thread wrapper.
To fix this, give the thread wrapper functions WeakAnyLinkage. This
prevents them from getting inlined into call-sites.
This fixes PR19989.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210632 91177308-0d34-0410-b5e6-96231b3b80d8
After some discussion, it was decided to use the Itanium ABI for thread_local on
Darwin OS X platforms. This involved a couple of changes. First, we use
"_tlv_atexit" instead of "__cxa_thread_atexit". Secondly, the global variables
are marked with 'internal' linkage, because we want all access to be calls to
the Itanium-specific entry point, which has normal linkage.
<rdar://problem/13733006>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180941 91177308-0d34-0410-b5e6-96231b3b80d8
Original commit message:
Emit the TLS intialization functions into a list.
Add the TLS initialization functions to a list of initialization functions. The
back-end takes this list and places the function pointers into the correct
section. This way they're called before `main().'
<rdar://problem/13733006>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180809 91177308-0d34-0410-b5e6-96231b3b80d8
Add the TLS initialization functions to a list of initialization functions. The
back-end takes this list and places the function pointers into the correct
section. This way they're called before `main().'
<rdar://problem/13733006>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180739 91177308-0d34-0410-b5e6-96231b3b80d8
Manman Ren