xgboost 2.0 build fails on osx because of a `overridden virtual function` caused by `std::make_shared`

[tylerjthomas9]

I am trying to build xgboost 2.0 for Julia. However, I am struggling to get the osx builds to work. I have narrowed it down to this commit that is causing issues with the osx build. I see that there are previous conversations on std::make_shared, but I am struggling to find any solutions for building with libc.

[19:46:11] In file included from /workspace/srcdir/xgboost/src/common/io.cc:25:
--
  | [19:46:11] In file included from /opt/aarch64-apple-darwin20/aarch64-apple-darwin20/sys-root/usr/include/c++/v1/algorithm:644:
  | [19:46:11] /opt/aarch64-apple-darwin20/aarch64-apple-darwin20/sys-root/usr/include/c++/v1/memory:3658:7: error: exception specification of overriding function is more lax than base version
  | [19:46:11] class __shared_ptr_emplace
  | [19:46:11]       ^
  | [19:46:11] /opt/aarch64-apple-darwin20/aarch64-apple-darwin20/sys-root/usr/include/c++/v1/memory:4331:26: note: in instantiation of template class 'std::__shared_ptr_emplace<xgboost::common::MmapResource, std::allocator<xgboost::common::MmapResource>>' requested here
  | [19:46:11]     ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
  | [19:46:11]                          ^
  | [19:46:11] /opt/aarch64-apple-darwin20/aarch64-apple-darwin20/sys-root/usr/include/c++/v1/memory:4710:29: note: in instantiation of function template specialization 'std::shared_ptr<xgboost::common::MmapResource>::make_shared<std::basic_string<char> &, unsigned long &, unsigned long &>' requested here
  | [19:46:11]     return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...);
  | [19:46:11]                             ^
  | [19:46:11] /workspace/srcdir/xgboost/src/common/io.h:387:40: note: in instantiation of function template specialization 'std::make_shared<xgboost::common::MmapResource, std::basic_string<char> &, unsigned long &, unsigned long &>' requested here
  | [19:46:11]       : AlignedResourceReadStream{std::make_shared<MmapResource>(path, offset, length)} {}
  | [19:46:11]                                        ^
  | [19:46:11] /opt/aarch64-apple-darwin20/aarch64-apple-darwin20/sys-root/usr/include/c++/v1/memory:3567:13: note: overridden virtual function is here
  | [19:46:11]     virtual ~__shared_weak_count();
  | [19:46:11]             ^

The full build log is here: https://buildkite.com/julialang/yggdrasil/builds/5173#018a9a59-ab3d-4d6d-937b-6179b2f6ac71

[trivialfis]

It's a bug in some versions of Apple clang. We can remove the make share as a workaround

[tylerjthomas9]

Is there something I should replace it with, or should I just drop all the references to make_shared?

[trivialfis]

From std::make_shared to std::shared_ptr<Type>(new Type{...}). I don't know what triggers the bug in Apple clang, so you can replace those until clang is happy.

[tylerjthomas9]

Thank you for the help. I managed to get the build to work. Just one make_shared instance had to be replaced. Here is the patch that I added:

+++ xgboost/src/common/io.h
@@ -384,7 +384,7 @@
    * @param length    See the `length` parameter of `mmap` for details.
    */
   explicit PrivateMmapConstStream(std::string path, std::size_t offset, std::size_t length)
-      : AlignedResourceReadStream{std::make_shared<MmapResource>(path, offset, length)} {}
+      : AlignedResourceReadStream{std::shared_ptr<MmapResource>(new MmapResource(path, offset, length))} {}
   ~PrivateMmapConstStream() noexcept(false) override;
 };