Windows releases of LLDB should have libxml2 enabled if possible

[DavidSpickett]

A user reported in https://discourse.llvm.org/t/does-lldb-qemu-support-dumping-x64-control-registers-such-as-cr3/89031 that they weren't getting the expected registers from QEMU, and the cause is their LLDB not supporting target XML descriptions.

The release script does build libxml2 but it is not enabled for LLDB, are there known problems with using it? We at least know the user in that thread was able to rebuild with it enabled to solve their own issue.

This working out of the box would be great because a lot of debug servers now assume the client will rely on target XML.

https://github.com/llvm/llvm-project/blob/main/llvm/utils/release/build_llvm_release.bat

set common_lldb_flags=^
  -DLLDB_RELOCATABLE_PYTHON=1 ^
  -DLLDB_EMBED_PYTHON_HOME=OFF ^
  -DLLDB_ENABLE_LIBXML2=OFF

[llvmbot]

@llvm/issue-subscribers-lldb

Author: David Spickett (DavidSpickett)

A user reported in https://discourse.llvm.org/t/does-lldb-qemu-support-dumping-x64-control-registers-such-as-cr3/89031 that they weren't getting the expected registers from QEMU, and the cause is their LLDB not supporting target XML descriptions.

The release script does build libxml2 but it is not enabled for LLDB, are there known problems with using it? We at least know the user in that thread was able to rebuild with it enabled to solve their own issue.

This working out of the box would be great because a lot of debug servers now assume the client will rely on target XML.

https://github.com/llvm/llvm-project/blob/main/llvm/utils/release/build_llvm_release.bat

set common_lldb_flags=^
  -DLLDB_RELOCATABLE_PYTHON=1 ^
  -DLLDB_EMBED_PYTHON_HOME=OFF ^
  -DLLDB_ENABLE_LIBXML2=OFF

[DavidSpickett]

@zmodem , @omjavaid have either of you tried this in the past?

[zmodem]

Hmm, I did see the Discourse thread, but I didn't expect it to come down to libxml :-)

I'll give it a try later today, but I suspect there was some reason that I added -DLLDB_ENABLE_LIBXML2=OFF in that first commit (145835c).

Also + @tstellar who's working on switching the release packaging to github actions.

[omjavaid]

@zmodem , @omjavaid have either of you tried this in the past?

I do remember there was a problem with LLDB and libxml when we first started building it in the release but not entirely remember the whole context. I will give it a try in 21.1.7

[zmodem]

If I also enable LIBXML2_WITH_SAX1, it works for me (building trunk for x86_64 Windows): #170513