1.87 build fails with LLVM 19

[bbhtt]

1.87 build fails with LLVM 19. Does 1.87 require LLVM 20+ or it's a bug?

        /buildstream-build/src/llvm-project/lld/COFF/Chunks.h:879:12: error: 'llvm::COFF::Arm64XFixupType' has not been declared
          879 |   void add(llvm::COFF::Arm64XFixupType type, uint8_t size,
              |            ^~~~
        /buildstream-build/src/llvm-project/lld/COFF/InputFiles.cpp: In member function 'std::optional<lld::coff::Symbol*> lld::coff::ObjFile::createDefined(llvm::object::COFFSymbolRef, std::vector<const llvm::object::coff_aux_section_definition*>&, bool&)':
        /buildstream-build/src/llvm-project/lld/COFF/InputFiles.cpp:770:11: error: 'class llvm::object::COFFSymbolRef' has no member named 'isEmptySectionDeclaration'
          770 |   if (sym.isEmptySectionDeclaration()) {
              |           ^~~~~~~~~~~~~~~~~~~~~~~~~
        In file included from /usr/include/c++/14.2.0/i686-unknown-linux-gnu/bits/c++allocator.h:33,
                         from /usr/include/c++/14.2.0/bits/allocator.h:46,
                         from /usr/include/c++/14.2.0/string:43,
                         from /usr/include/llvm/ADT/Hashing.h:56,
                         from /buildstream-build/src/llvm-project/lld/include/lld/Common/LLVM.h:19,
                         from /buildstream-build/src/llvm-project/lld/include/lld/Common/ErrorHandler.h:71,
                         from /buildstream-build/src/llvm-project/lld/COFF/Config.h:12,
                         from /buildstream-build/src/llvm-project/lld/COFF/InputFiles.h:12,
                         from /buildstream-build/src/llvm-project/lld/COFF/InputFiles.cpp:9:
        /usr/include/c++/14.2.0/bits/new_allocator.h: In instantiation of 'void std::__new_allocator<_Tp>::construct(_Up*, _Args&& ...) [with _Up = lld::coff::Arm64XDynamicRelocEntry; _Args = {int&, unsigned char&, lld::coff::Arm64XRelocVal&, lld::coff::Arm64XRelocVal&}; _Tp = lld::coff::Arm64XDynamicRelocEntry]':
        /usr/include/c++/14.2.0/bits/alloc_traits.h:534:17:   required from 'static void std::allocator_traits<std::allocator<_CharT> >::construct(allocator_type&, _Up*, _Args&& ...) [with _Up = lld::coff::Arm64XDynamicRelocEntry; _Args = {int&, unsigned char&, lld::coff::Arm64XRelocVal&, lld::coff::Arm64XRelocVal&}; _Tp = lld::coff::Arm64XDynamicRelocEntry; allocator_type = std::allocator<lld::coff::Arm64XDynamicRelocEntry>]'
          534 |           __a.construct(__p, std::forward<_Args>(__args)...);
              |           ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        /usr/include/c++/14.2.0/bits/vector.tcc:117:30:   required from 'std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {int&, unsigned char&, lld::coff::Arm64XRelocVal&, lld::coff::Arm64XRelocVal&}; _Tp = lld::coff::Arm64XDynamicRelocEntry; _Alloc = std::allocator<lld::coff::Arm64XDynamicRelocEntry>; reference = lld::coff::Arm64XDynamicRelocEntry&]'
          117 |             _Alloc_traits::construct(this->_M_impl, this->_M_impl._M_finish,
              |             ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          118 |                                      std::forward<_Args>(__args)...);
              |                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        /buildstream-build/src/llvm-project/lld/COFF/Chunks.h:881:30:   required from here
          881 |     arm64xRelocs.emplace_back(type, size, offset, value);
              |     ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
        /usr/include/c++/14.2.0/bits/new_allocator.h:191:11: error: no matching function for call to 'lld::coff::Arm64XDynamicRelocEntry::Arm64XDynamicRelocEntry(int&, unsigned char&, lld::coff::Arm64XRelocVal&, lld::coff::Arm64XRelocVal&)'
          191 |         { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
              |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        /buildstream-build/src/llvm-project/lld/COFF/Chunks.h:854:7: note: candidate: 'lld::coff::Arm64XDynamicRelocEntry::Arm64XDynamicRelocEntry()'
          854 | class Arm64XDynamicRelocEntry {
              |       ^~~~~~~~~~~~~~~~~~~~~~~
        /buildstream-build/src/llvm-project/lld/COFF/Chunks.h:854:7: note:   candidate expects 0 arguments, 4 provided
        /buildstream-build/src/llvm-project/lld/COFF/Chunks.h:854:7: note: candidate: 'constexpr lld::coff::Arm64XDynamicRelocEntry::Arm64XDynamicRelocEntry(const lld::coff::Arm64XDynamicRelocEntry&)'
        /buildstream-build/src/llvm-project/lld/COFF/Chunks.h:854:7: note:   candidate expects 1 argument, 4 provided
        /buildstream-build/src/llvm-project/lld/COFF/Chunks.h:854:7: note: candidate: 'constexpr lld::coff::Arm64XDynamicRelocEntry::Arm64XDynamicRelocEntry(lld::coff::Arm64XDynamicRelocEntry&&)'
        /buildstream-build/src/llvm-project/lld/COFF/Chunks.h:854:7: note:   candidate expects 1 argument, 4 provided

[dianqk]

This looks like an internal LLVM build error.

[onur-ozkan]

We are using LLVM 20 since this, but LLVM 19 should work too, I guess... I haven't tested yet.

[bbhtt]

Building with LLVM 20 works for me too, but LLVM is frozen to 19 in one of our stable branches.

[nikic]

My best guess is that you're using some broken build configuration that tries to use an external LLVM 19 while also building an LLVM 20 LLD? Can you please share your config file?

[bbhtt]

The same configuration works for LLVM 20 in master https://gitlab.com/freedesktop-sdk/freedesktop-sdk/-/merge_requests/26419

These are with LLVM 19 on the release/24.08 branch:

https://gitlab.com/freedesktop-sdk/freedesktop-sdk/-/blob/8d3e68a3aa0619b9ddb85ae6ff582d603e24a5d4/elements/components/rust.bst#L89

Build log: rust.txt

[nikic]

The config looks reasonable to me. Maybe there's a bootstrap bug that makes this comment not true:

rust/bootstrap.example.toml

Lines 720 to 725 in e7f4317

	# Indicates whether LLD will be compiled and made available in the sysroot for rustc to execute, and
	# whether to set it as rustc's default linker on `x86_64-unknown-linux-gnu`. This will also only be
	# when *not* building an external LLVM (so only when using `download-ci-llvm` or building LLVM from
	# the in-tree source): setting `llvm-config` in the `[target.x86_64-unknown-linux-gnu]` section will
	# make this default to false.
	#lld = false in all cases, except on `x86_64-unknown-linux-gnu` as described above, where it is true

But explicitly setting lld = false should probably fix it?

[bbhtt]

But explicitly setting lld = false should probably fix it?

That seems to have worked

https://gitlab.com/freedesktop-sdk/freedesktop-sdk/-/merge_requests/26458

[onur-ozkan]

On master, since #139853, you won't be able to compile in-tree lld with external LLVM. So this error isn't reproducible on master today.

[bbhtt]

I see, feel free to close then if there is a check against this mixed behaviour. We also switched to our LLVM's lld in the master branch.