keys.gen

#!/bin/sh -ue
source=${1?Missing source file}
export LC_ALL=C

echo "/* Automatically generated by $0. Do not edit. */"
echo
echo '#pragma GCC diagnostic push'
echo '#pragma GCC diagnostic ignored "-Wmissing-field-initializers"'
echo '#pragma GCC diagnostic ignored "-Wunused-parameter"'

sed -n '/K_[a-zA-Z_.-]*_parse/{s/.*\(K_[a-zA-Z_.-]*\)_parse.*/\1/p}' "$source" |
sort |
uniq |
while read -r name
do
	table=$(
		sed -n '/_\(parse\|none\)/! {
			/'$name'_[a-zA-Z_.-]*/ {
				s:.*\('$name'_\([a-zA-Z_.-]*\)\).*:\2,\t\1:
				: subst_dashes
					s:^\([^,]*\)__:\1-:
				t subst_dashes
				p
			}
		}' "$source" |
		sort |
		uniq
	)
	gperf <<EOF
%language=ANSI-C
%7bit
%enum
%readonly-tables
%define hash-function-name ${name}_hash_
%define lookup-function-name ${name}_lookup_
%{
enum ${name}_e_ {
	${name}_none
$(printf '%s' "$table" | sed 's/.*\t\(.*\)/\t, \1/')
};
%}
%struct-type
struct ${name}_s_ { char const *const name; enum ${name}_e_ const idx; }
%%
$table
%%
static enum ${name}_e_
${name}_parse (register char const *str)
{
	register struct ${name}_s_ const *const h = ${name}_lookup_ (str, strlen(str));
	return NULL != h ? h->idx : ${name}_none;
}
EOF
done

echo '#pragma GCC diagnostic pop'
echo '/* vim'':set ft=c: */'