what is the best practice to put all cpp source files in one single file and load it into meson.build

[newcfd]

Need to put all header files and include dir names into a single file as well

[eli-schwartz]

Do you mean you want to do a Unity build? Meson has builtin support for this, see https://mesonbuild.com/Unity-builds.html

Just run meson setup with the additional option --unity on. List all your sources and include directories as normal.

Need to put all header files and include dir names into a single file as well

Header files are by definition handled (transitively) by putting all cpp source files into one file.

Compiler technologies do not include the concept of putting include dir names into a file, but meson will collect them for you and pass them all at the same time to the unity file.

[newcfd]

Thank for your reply. Simply want to put all cpp source and header files into single files under meson_config dir and load them into meson.build.

[dcbaker]

Do you mean "I have multiple build systems, and I want to list the files once in a plain text file and read them in all of my build systems instead of copying the list between them"?

[newcfd]

Switching to meson from cmake since meson build is way faster. Plan to put a source, header and include path list files under meson_config dir. source list file has all source files, same for header and include list files. Import or load these three files into meson.build. This can be done with include in cmake easily. How to do this in meson?

[dcbaker]

meson has the fs module, which would make reading a text file with a character delimited list straightfoward (assuming newline separated):

fs = import('fs')
srcs = files(fs.read('files.list').split())
includes = include_directories(fs.read('includes.list').split())

fs.read returns a string of the contents, so you can use normal string opertions like .split on it