[LLVMdev] RFC: Timeline for deprecating the autoconf build system?

[Steven Stewart-Gallus]

I am an actual end user of LLVM who builds it from source and not a
developer of it so I think I have an important perspective that is not
represented here. Also I am pretty sure the llvmdev mailing is heavily
biased and might not reach actual end users of LLVM. I use the
Autotools build system for a number of reasons. If compromises or
reasonable workarounds could be found I would be okay with the switch
to CMake.

- CMake is poorly documented and difficult to use as an end
  user. There are a number of arcane switches and settings that are
  hard to find and figure out what they do. Moreover, certain
  important functionality is just plain lacking.

- I already have an Autotools configuration file that sets default
  settings for the local installation prefix (to
  "$HOME/root/usr/local") and the LDFLAGS (to
  "-Wl,-rpath,${HOME}/root/usr/local/lib
  -Wl,-rpath,${HOME}/root/usr/local/lib64"). I don't if it's possible
  to set such defaults for CMake and even if it is the difficulty in
  finding how to do so is a bad sign.

- In Autotols the installation directory is overridable at install
  time so I can set the prefix variable to a different directory such
  as "$HOME/root/usr/local/stow/llvm" and using GNU Stow have easy
  package management and isolation between software. CMake does not
  offer such a capability or is so poorly documentated that it is
  impossible to find out how to do so.

Overall, CMake isn't a bad build system for actually building software
but simply lacks the appropriate polish and documentation that makes
it easy for end users to use.

Thank you,
Steven Stewart-Gallus