buffer-auto-save-file-name

buffer-auto-save-file-name is a variable defined in `C source code'.
Its value is

nil

global value is the same.

• Automatically becomes permanently buffer-local when set.
• This variable may be risky if used as a file-local variable.

Documentation:
Name of file for auto-saving current buffer.
If it is nil, that means don't auto-save this buffer.