Add compatibility flags of POSIX make
Those were seen in the POSIX make documentation:
- -a, -b, -m - ignored for compatibility or free - for agmake they are free for use!
- -B, --always-make - make all unconditionally
- -C - cd to dir; MULTIPLE directories can be specified and they are glued together!
- --debug[=FLAGS] - debugging information: b:basic v:verbose i:implicit-rules j:invokation m:remaking
- -e: make environment variables take precedence over variables in makefile (may be impossible)
- -i: try-hard: ignore errors from executed commands, go on as if nothing wrong happened
- -I: module directory (probably requires adding an "include" command, which will be almost same as "source" except added module directory)
- -L: use latest mtime between symlinks and target - probably it's about taking mtime from whichever is fresher
- -n: dry-run
- -o : exclude file from checking dependencies and do not remake it
- -p: print database that is built from the makefiles (then continue normally)
- -q: only test given target if it's up to date or needs to be remade, return exit code 0 if the target is fresh
- -r: no builtin rules (builtin rules are not a feature anyway, probably needs to be added)
- -R: no builtin variables (make uses, for example, default rule to compile C file: $(CC) -c $(CFLAGS) $(CPPFLAGS) - this would have to be added as feature)
- -s: silent: do not echo executed commands
- -S: invert -k should it have been set through MAKEFLAGS or by earlier option
- -t: touch stale files instead of remaking them
- -v: version (NOT VERBOSE!)
- -w: print PWD before making
- -W : simulate the situation of having the file touched
- --eval=STRING - same as currently -x