[libcxx-commits] [PATCH] D66177: Update shared_ptr's constructor

[Louis Dionne via Phabricator via libcxx-commits]

ldionne requested changes to this revision.
ldionne added inline comments.
This revision now requires changes to proceed.


================
Comment at: libcxx/include/memory:3979
+    : __ptr_(__p),
+      __cntrl_(__allocate_shared(__p))
 {
----------------
Before, we would create the control block with `new`, and with this patch we're using the allocator. Is this correct? Why?

Also, we're now unconditionally using a try-catch block -- I'd be curious to see what the impact on code generation is.


================
Comment at: libcxx/include/memory:3991
 {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
-        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
-        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
-        __enable_weak_this(__p, __p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
+    __enable_weak_this(__p, __p);
 }
----------------
Note to reviewers: It's okay to move this outside of the try-catch block, since `__enable_weak_this` is `noexcept` anyway.


Repository:
  rCXX libc++

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D66177/new/

https://reviews.llvm.org/D66177