Only log to a file without logging to stderr

[jian-lin]

Is your feature request related to a problem? Please describe.

If Emacs runs inside a terminal emulator, using emacs-rime destroys the current screen of Emacs because librime logs to stderr.

Describe the solution you'd like
I want to be able to not log to stderr when logging is enabled.

Additional context

Removing this single line is a possible implementation. However, in that case, you have to set log_dir to an empty string to log to stderr, which is not very intuitive. In addition, this seems to be a breaking change.

librime/src/rime/setup.cc

Line 81 in 72f833d

FLAGS_alsologtostderr = true;

Maybe a new option should be added to rime api for this new feature.

[lotem]

I guess a compile-time flag should work for emacs-rime?
How about creating a new CMake option LOG_TO_STDERR, and use it to fill the value with a C macro

FLAGS_alsologtostderr = RIME_LOG_TO_STDERR;

[jian-lin]

I guess a compile-time flag should work for emacs-rime?

If possible, I want to use librime from my Linux distribution instead of changing cmake options and compiling it myself. So both a cmake option defaulting to off (the linked PR) and a rime api option work well for me.

[lotem]

OK. I think it's appropriate to only enable logging to stderr in debug build.