section in libc++. This requires a recompiled dylib. Failure to rebuild
the dylib will result in a link-time error if and only if the functions from
[util.smartptr.shared.atomic] are used.
The implementation is not lock free. After considerable thought, I know of no
way to make the implementation lock free. Ideas welcome along that front. But
changing the ABI of shared_ptr is not on the table at this point.
The mutex used to lock these function is encapsulated by std::__sp_mut. The
only thing the client knows about std::__sp_mut is that it has a void* data
member, can't be constructed, and has lock and unlock members. Within the
binary __sp_mut is currently implemented as a pointer to a std::mutex. That can
change in the future without disturbing the ABI (as long as sizeof(__sp_mut)
remains constant.
I specifically did not make __sp_mut a spin lock as I have a pathological
distrust of spin locks. Testing on OS X reveals that the use of std::mutex in
this role is not a large performance penalty as long as the contention for the
mutex is low (more likely to get the lock than to have to wait). In the future
we can still make __sp_mut a spin lock if that is what is desired (without ABI
damage).
The dylib contains 16 __sp_mut's to be chosen based on the hash of the address
of the shared_ptr. The constant 16 is a ball-park reasonable space/time
tradeoff.
std::hash<T*> was changed to call __murmur2_or_cityhash, instead of the identity
function. I had thought we had already done this, but I was mistaken.
All of this is under #if __has_feature(cxx_atomic) even though the
implementation is not lock free, because the signatures require access to
std::memory_order, which is currently available only under
__has_feature(cxx_atomic).
llvm-svn: 160940
consistent application of visibility attributes, which causes some new
breakage in libcxxabi:
In file included from src/libcxxabi/src/cxa_default_handlers.cpp:19:
src/libcxxabi/src/private_typeinfo.h:123:23: error: visibility does
not match previous declaration
class __attribute__ ((__visibility__(default))) __class_type_info
^
src/libcxxabi/src/private_typeinfo.h:19:13: note: previous attribute is here
#pragma GCC visibility push(hidden)
^
1 error generated.
The forward declaration of __class_type_info is picking up hidden
visibility from the #pragma, which conflicts with the default
visibility applied when the class is later fully declared. I'm
assuming that the full declaration has it right (and that the
diagnostic is correct), so the attached patch applies the default
visibility attribute to the forward declaration.
llvm-svn: 160933
expressions to have complete return types (or accessible destructors). If the
return type is required to be complete for some other reason (for instance, if
it is needed by overload resolution), then it will still be required to be
complete. This is apparently required in order to parse a MSVC11 header.
llvm-svn: 160924
Machine CSE and other optimizations can remove instructions so folding
is possible at peephole while not possible at ISel.
rdar://10554090 and rdar://11873276
llvm-svn: 160919
It is possible that an instruction can use and update EFLAGS.
When checking the safety, we should check the usage of EFLAGS first before
declaring it is safe to optimize due to the update.
llvm-svn: 160912
Objective-C method names when looking for functions
in the top level or a namespace. Method names should
only be found via FindExternalLexicalDecls.
<rdar://problem/11711679>
llvm-svn: 160907
Convert from calling Halt in the lldb Driver.cpp's input reader's sigint handler to sending this AsyncInterrupt so it can be handled in the
event loop.
If you are attaching and get an async interrupt, abort the attach attempt.
Also remember to destroy the process if get interrupted while attaching.
Getting this to work also required handing the eBroadcastBitInterrupt in a few more places in Process WaitForEvent & friends.
<rdar://problem/10792425>
llvm-svn: 160903
A value number is a PHI def if and only if it begins at a block
boundary. This can be derived from the def slot, a separate flag is not
necessary.
llvm-svn: 160893
This option replaces the existing live interval computation with one
based on LiveRangeCalc.cpp. The new algorithm does not depend on
LiveVariables, and it can be run at any time, before or after leaving
SSA form.
llvm-svn: 160892
hex: ) during comment parsing.
Now internal representation of plain text in comment AST does not contain
character references, but the characters themselves.
llvm-svn: 160891
sel_getName() calls are generated for all Objective-C
selectors before static literals are moved to the
static allocation. This prevents errors of the form
Internal error [IRForTarget]: Couldn't change a static
reference to an Objective-C selector to a dynamic
reference
<rdar://problem/11331906>
llvm-svn: 160887
Clang's -Wformat fix-its currently suggest using "%zu" for values of
type size_t (in C99 or C++11 mode). However, for a type such as
std::vector<T>::size_type, it does not notice that type is actually
typedeffed to size_t, and instead suggests a format for the underlying
type, such as "%lu" or "%u".
This commit makes the format string fix mechanism walk the typedef chain
so that it notices if the type is size_t, even if that isn't "at the
top".
llvm-svn: 160886
Also, fix a subtle bug, which occurred due to lookupPrivateMethod
defined in DeclObjC.h not looking up the method inside parent's
categories.
Note, the code assumes that Class's parent object has the same methods
as what's in the Root class of a the hierarchy, which is a heuristic
that might not hold for hierarchies which do not descend from NSObject.
Would be great to fix this in the future.
llvm-svn: 160885
Craig Topper