Help with Autotools and Mixed Mode

[mathomp4]

I have recently been trying to build and test FMS 2021.03 with GEOS as a library. Now, in GEOS we run our FV3 as 32-bit and MOM6 as 64-bit. In our current old FMS, we build it twice inside GEOS as an "fms_r4" and "fms_r8". Now it looks like the CMake build of FMS might support something like that:

FMS/CMakeLists.txt

Lines 228 to 232 in a7b4e6d

	foreach(kind ${kinds})
	set(libTgt fms_${kind})
	set(includeDir "include_${kind}")
	set(moduleDir "${CMAKE_CURRENT_BINARY_DIR}/${includeDir}")

But because of issues I was having with the CMake build, I tried out the Autotools build. I did see there was a --enable-mixed-mode flag, but it looks like that doesn't do a include_r4 and include_r8? Right? Is there something else I might need to set in Autotools to have it do that?

[rem1776]

The --enable-mixed-mode flag is more analogous to building with just the 32-bit option in CMake. It'll set up the makefiles for one build with the OVERLOAD_R8 and OVERLOAD_R4 flags, but instead of those include_r* directories being created the module files will be in the build directory in .mods.

So if you did two builds, one with the mixed mode enabled and one without you would get the files from the include_r* directories in the respective .mods directories

[mathomp4]

The --enable-mixed-mode flag is more analogous to building with just the 32-bit option in CMake. It'll set up the makefiles for one build with the OVERLOAD_R8 and OVERLOAD_R4 flags, but instead of those include_r* directories being created the module files will be in the build directory in .mods.

So if you did two builds, one with the mixed mode enabled and one without you would get the files from the include_r* directories in the respective .mods directories

Ah I see. Okay. So I'd have to build it twice myself (which is I guess what CMake is doing). Well, I was able to get the CMake build to work for me, so I might stick with that. But if you can think of an autotools way, I could look at trying it out. (Though I suppose the more CMake I use the better, since I can read CMake. Autotools is...cryptic! 😄 )