#! /usr/bin/awk -f
#	$NetBSD: gendevcalls.awk,v 1.1 2021/09/15 17:25:14 thorpej Exp $
#
# Copyright (c) 2021 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Jason R. Thorpe.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#

#
# Parses a device call definition file and produces argument and
# binding structures.
#

function emit_binding(field) {
	printf("union %s_binding {\n", call_name_ub)
	printf("\tstruct device_call_generic generic;\n")
	if (field != "") {
		printf("\tstruct {\n")
		printf("\t\tconst char *name;\n")
		printf("\t\tstruct %s_args *args;\n", call_name_ub)
		printf("\t} %s;\n", field);
	}
	printf("};\n")
}

function emit_name_macro() {
	printf("\n")
	printf("#define %s_STR \"%s\"\n", call_name_ub_uc, call_name)
}

function emit_invoke_macro(field, marg, carg) {
	printf("\n")
	printf("#define %s%s \\\n", call_name_ub_uc, marg)
	printf("\t&((const union %s_binding){ \\\n", call_name_ub)
	printf("\t\t.%s.name = \"%s\", \\\n", field, call_name)
	printf("\t\t.%s.args = %s, \\\n", field, carg)
	printf("\t})\n")
}

function start_decl(arg) {
	if (state == "expecting-subsystem") {
		print "must declare a subsystem before declaring a call " \
		    "at line " NR \
		    > "/dev/stderr"
		exit 1
	}

	if (state != "expecting-decl-start") {
		print "unexpected start of declaration at line " NR \
		    > "/dev/stderr"
		exit 1
	}

	call_name = arg

	if (index(call_name, call_name_prefix) != 1) {
		printf("method name '%s' at line %d must begin with '%s'\n", \
		    call_name, NR, call_name_prefix) \
		    > "/dev/stderr"
		exit 1
	}

	call_name_ub = arg
	gsub("\-", "_", call_name_ub)
	call_name_ub_uc = toupper(call_name_ub)
}

NR == 1 {
	VERSION = $0
	gsub("\\$", "", VERSION)
	gsub(/ $/, "", VERSION)

	printf("/*\t$NetBSD" "$\t*/\n\n")
	printf("/*\n")
	printf(" * THIS FILE IS AUTOMATICALLY GENERATED.  DO NOT EDIT.\n")
	printf(" *\n")
	printf(" * generated from:\n")
	printf(" *\t%s\n", VERSION)
	printf(" */\n")

	subsystem = ""
	state = "expecting-subsystem"

	next
}
#
# Subystem declaration.  We use this to generate header file guards,
# as well as to sanity-check the method names when they are declared.
#
state == "expecting-subsystem" && \
/^subsystem[ \t]+[a-zA-Z]+[a-zA-Z0-9\-]*[ \t]*;[ \t]*$/ {
	subsystem = $2

	# strip the trailing ;
	gsub(";$", "", subsystem)

	subsystem_ub = subsystem
	gsub("\-", "_", subsystem_ub)
	subsystem_ub_uc = toupper(subsystem_ub)

	# now tack on a trailing - for sanity checking method
	# names later.
	call_name_prefix = subsystem "-"

	# Emit the leading header guard.
	printf("#ifndef _%s_CALLS_H_\n", subsystem_ub_uc)
	printf("#define _%s_CALLS_H_\n", subsystem_ub_uc)

	# Pull in <sys/device.h> for 'struct device_call_generic'.
	printf("\n#include <sys/device.h>\n")

	state = "expecting-decl-start"

	next
}
#
# Beginning of a call-with-arguments declaration.  Gather up the various
# forms of the method name and emit the beginning of the structure declaration.
#
/^[a-zA-Z]+[a-zA-Z0-9\-]*[ \t]+{[ \t]*$/ {
	start_decl($1)

	# Emit the args structure declaration.
	printf("struct %s_args {\n", call_name_ub)

	state = "expecting-decl-end"

	next
}
#
# A call-without-arguments declaration.
#
/^[a-zA-Z]+[a-zA-Z0-9\-]*[ \t]*;[ \t]*$/ {
	# strip the trailing ;
	call_name = $1
	gsub(";$", "", call_name)

	start_decl(call_name)

	emit_binding("")
	emit_name_macro()
	emit_invoke_macro("generic", "", "NULL")

	next
}
#
# End of a declaration.  Wrap up the structure declaration and emit
# the binding information.
#
/^}[ \t]*;[ \t]*$/ {
	if (state != "expecting-decl-end") {
		print "unexpected end of declaration at line " NR \
		    > "/dev/stderr"
		exit 1
	}

	# Terminate the args structure declaration.
	printf("};\n")

	printf("\n")
	emit_binding("binding")
	emit_name_macro()
	emit_invoke_macro("binding", "(_args_)", "(_args_)")

	state = "expecting-decl-start"

	next
}
#
# Default action is to simply emit the line as it exists in the source
# file.
#
{
	print $0
}
END {
	if (state != "expecting-decl-start") {
		print "unexpected end of file at line " NR \
		    > "/dev/stderr"
		exit 1
	}

	# Emit the trailing header guard.
	printf("\n#endif /* _%s_CALLS_H_ */\n", subsystem_ub_uc)
}