[BUG] Cannot be built in an environment where fmt and spdlog are installed independently.

[gdaisukesuzuki]

File bug happens
arena.hpp
arena_memory_resource.hpp

Issues to be fixed
Both header files are assumed to be built on spdlog, where fmt is bundled, and not in an environment where fmt and spglog are installed separately.

Suggested patch

*** rmm/include/rmm/mr/device/detail/arena.hpp-dist     2021-11-03 23:02:58.084936643 +0900
--- rmm/include/rmm/mr/device/detail/arena.hpp  2021-11-03 23:04:31.726165374 +0900
***************
*** 24,30 ****
  #include <cuda_runtime_api.h>
  
  #include <spdlog/common.h>
! #include <spdlog/fmt/bundled/ostream.h>
  
  #include <algorithm>
  #include <cstddef>
--- 24,35 ----
  #include <cuda_runtime_api.h>
  
  #include <spdlog/common.h>
! #if !defined(SPDLOG_FMT_EXTERNAL)
! #      include <spdlog/fmt/bundled/ostream.h>
! #else
! #      include <fmt/ostream.h>
! #endif
! 
  
  #include <algorithm>
  #include <cstddef>
*** rmm/include/rmm/mr/device/arena_memory_resource.hpp-dist    2021-11-03 23:53:12.040547640 +0900
--- rmm/include/rmm/mr/device/arena_memory_resource.hpp 2021-11-03 23:54:49.082345112 +0900
***************
*** 23,29 ****
  #include <cuda_runtime_api.h>
  
  #include <spdlog/common.h>
! #include <spdlog/fmt/bundled/ostream.h>
  
  #include <cstddef>
  #include <map>
--- 23,34 ----
  #include <cuda_runtime_api.h>
  
  #include <spdlog/common.h>
! #if !defined(SPDLOG_FMT_EXTERNAL)
! #      include <spdlog/fmt/bundled/ostream.h>
! #else
! #      include <fmt/ostream.h>
! #endif
! 
  
  #include <cstddef>
  #include <map>

---

[harrism]

I think it would be nice to just be able to use the #include <fmt/ostream.h> always. So we should either depend on fmt directly, or add a -I compiler option pointing to the location of spdlog.

[harrism]

@robertmaynard given we get spdlog with cpm, is there a simple way in cmake to add -I<spdlog_install_dir>/fmt to the command line?

[harrism]

Just realized spdlog puts its bundled fmt in spdlog/fmt/bundled, not just in spdlog/fmt. So maybe that won't work.

[gdaisukesuzuki]

I think the way the 2 files should be modified as the following file (which calls fmt) is written.

/usr/include/spdlog/fmt/fmt.h

[robertmaynard]

It looks like spdlog provides wrapper headers that should be used instead of directly including anything in the bundled directory.

For example for ostream we should be using spdlog/fmt/osr.h which computes the correct header based on SPDLOG_FMT_EXTERNAL

[robertmaynard]

#907 Should resolve this issue