shithub: rgbds

ref: b4dadd35b6ea22192b3b68b042f439caa0dd0566
dir: /contrib/bash_compl/_rgbasm.bash/

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#/usr/bin/env bash

# Known bugs:
# - Newlines in file/directory names break this script
#   This is because we rely on `compgen -A`, which is broken like this.
#   A fix would require implementing it ourselves, and no thanks!
# - `rgbasm --binary-digits=a` is treated the same as `rgbasm --binary-digits=` (for example)
#   This is not our fault, Bash passes both of these identically.
#   Maybe it could be worked around, but such a fix would likely be involved.
#   The user can work around it by typing `--binary-digits ''` instead, for example.
# - Directories are not completed as such in "coalesced" short-opt arguments. For example,
#   `rgbasm -M d<tab>` can autocomplete to `rgbasm -M dir/` (no space), but
#   `rgbasm -Md<tab>` would autocomplete to `rgbasm -Mdir ` (trailing space) instead.
#   This is because dircetory handling is performed by Readline, whom we can't tell about the short
#   opt kerfuffle. The user can work around by separating the argument, as shown above.
#   (Also, there might be more possible bugs if `-Mdir` is actually a directory. Ugh.)

# Something to note:
# `rgbasm --binary-digits=a` gets passed to us as ('rgbasm' '--binary-digits' '=' 'a')
# Thus, we don't need to do much to handle that form of argument passing: skip '=' after long opts.

_rgbasm_completions() {
	COMPREPLY=()

	# Format: "long_opt:state_after"
	# Empty long opt = it doesn't exit
	# See the `state` variable below for info about `state_after`
	declare -A opts=(
		[V]="version:normal"
		[E]="export-all:normal"
		[h]="halt-without-nop:normal"
		[L]="preserve-ld:normal"
		[v]="verbose:normal"
		[w]=":normal"
		[b]="binary-digits:unk"
		[D]="define:unk"
		[g]="gfx-chars:unk"
		[i]="include:dir"
		[M]="dependfile:glob-*.mk *.d"
		[o]="output:glob-*.o"
		[p]="pad-value:unk"
		[r]="recursion-depth:unk"
		[W]="warning:warning"
	)
	# Parse command-line up to current word
	local opt_ena=true
	# Possible states:
	# - normal  = Well, normal. Options are parsed normally.
	# - unk     = An argument that can't be completed, and should just be skipped.
	# - warning = A warning flag.
	# - dir     = A directory path
	# - glob-*  = A glob, after the dash is a whitespace-separated list of file globs to use
	local state=normal
	# The length of the option, used as a return value by the function below
	local optlen=0
	# $1: a short option word
	# `state` will be set to the parsing state after the last option character in the word. If
	# "normal" is not returned, `optlen` will be set to the length (dash included) of the "option"
	# part of the argument.
	parse_short_opt() {
		for (( i = 1; i < "${#1}"; i++ )); do
			# If the option is not known, assume it doesn't take an argument
			local opt="${opts["${1:$i:1}"]:-":normal"}"
			state="${opt#*:}"
			# If the option takes an argument, record the length and exit
			if [[ "$state" != 'normal' ]]; then
				let optlen="$i + 1"
				return
			fi
		done
		optlen=0
	}

	for (( i = 1; i < $COMP_CWORD; i++ )); do
		local word="${COMP_WORDS[$i]}"

		# If currently processing an argument, skip this word
		if [[ "$state" != 'normal' ]]; then
			state=normal
			continue
		fi

		if [[ "$word" = '--' ]]; then
			# Options stop being parsed after this
			opt_ena=false
			break
		fi

		# Check if it's a long option
		if [[ "${word:0:2}" = '--' ]]; then
			# If the option is unknown, assume it takes no arguments: keep the state at "normal"
			for long_opt in "${opts[@]}"; do
				if [[ "$word" = "--${long_opt%%:*}" ]]; then
					state="${long_opt#*:}"
					# Check if the next word is just '='; if so, skip it, the argument must follow
					# (See "known bugs" at the top of this script)
					let i++
					if [[ "${COMP_WORDS[$i]}" != '=' ]]; then
						let i--
					fi
					optlen=0
					break
				fi
			done
		# Check if it's a short option
		elif [[ "${word:0:1}" = '-' ]]; then
			# The `-M?` ones are a mix of short and long, augh
			# They must match the *full* word, but only take a single dash
			# So, handle them here
			if [[ "$1" = "-M"[GP] ]]; then
				state=normal
			elif [[ "$1" = "-M"[TQ] ]]; then
				state='glob-*.d *.mk *.o'
			else
				parse_short_opt "$word"
				# The last option takes an argument...
				if [[ "$state" != 'normal' ]]; then
					if [[ "$optlen" -ne "${#word}" ]]; then
						# If it's contained within the word, we won't complete it, revert to "normal"
						state=normal
					else
						# Otherwise, complete it, but start at the beginning of *that* word
						optlen=0
					fi
				fi
			fi
		fi
	done

	# Parse current word
	# Careful that it might look like an option, so use `--` aggressively!
	local cur_word="${COMP_WORDS[$COMP_CWORD]}"

	# Process options, as short ones may change the state
	if $opt_ena && [[ "$state" = 'normal' && "${cur_word:0:1}" = '-' ]]; then
		# We might want to complete to an option or an arg to that option
		# Parse the option word to check
		# There's no whitespace in the option names, so we can ride a little dirty...

		# Is this a long option?
		if [[ "${cur_word:1:1}" = '-' ]]; then
			# It is, try to complete one
			COMPREPLY+=( $(compgen -W "${opts[*]%%:*}" -P '--' -- "${cur_word#--}") )
			return 0
		else
			# Short options may be grouped, parse them to determine what to complete
			# The `-M?` ones may not be followed by anything
			if [[ "$1" != "-M"[GPTQ] ]]; then
				parse_short_opt "$cur_word"
				# We got some short options that behave like long ones
				COMPREPLY+=( $(compgen -W '-MG -MP -MT -MQ' -- "$cur_word") )

				if [[ "$state" = 'normal' ]]; then
					COMPREPLY+=( $(compgen -W "${!opts[*]}" -P "$cur_word" '') )
					return 0
				elif [[ "$optlen" = "${#cur_word}" && "$state" != "warning" ]]; then
					# This short option group only awaits its argument!
					# Post the option group as-is as a reply so that Readline inserts a space,
					# so that the next completion request switches to the argument
					# An exception is made for warnings, since it's idiomatic to stick them to the
					# `-W`, and it doesn't break anything.
					COMPREPLY+=( "$cur_word" )
					return 0
				fi
			fi
		fi
	fi

	case "$state" in
		unk) # Return with no replies: no idea what to complete!
			;;
		warning)
			COMPREPLY+=( $(compgen -W "
				assert
				backwards-for
				builtin-args
				charmap-redef
				div
				empty-data-directive
				empty-macro-arg
				empty-strrpl
				large-constant
				long-string
				macro-shift
				nested-comment
				numeric-string
				obsolete
				shift
				shift-amount
				truncation
				user
				all
				extra
				everything
				error" -P "${cur_word:0:$optlen}" -- "${cur_word:$optlen}") )
			;;
		normal) # Acts like a glob...
			state="glob-*.asm *.inc *.sm83"
			;&
		glob-*)
			while read -r word; do
				COMPREPLY+=("${cur_word:0:$optlen}$word")
			done < <(for glob in ${state#glob-}; do compgen -A file -X \!"$glob" -- "${cur_word:$optlen}"; done)
			# Also complete directories
			;&
		dir)
			while read -r word; do
				COMPREPLY+=("${cur_word:0:$optlen}$word")
			done < <(compgen -A directory -- "${cur_word:$optlen}")
			compopt -o filenames
			;;
	esac
}

complete -F _rgbasm_completions rgbasm