upd6

make.vsh

@@ -0,0 +1,95 @@
+#!/usr/bin/env -S v run
+
+import os
+import rand
+import strings
+
+/*
+	This is a C bindings generator for netio module.
+
+	This script uses the C preprocessor (`cc`) to extract macros using programs
+	from `cincludes` and generates a V module file with constants.
+
+	The C defines (`#define`) are parsed and used to generate a temporary
+	V program (`vprogram`), which generates the final V module file.
+
+	The goal is for the final V module file to contain only the values of C
+	constants, rather than calling C code directly.
+*/
+
+const cincludes = {
+	'Linux':   '
+		|#include <netinet/in.h>
+		|#include <sys/socket.h>
+		|#include <netdb.h>'
+	'FreeBSD': '
+		|#include <netinet/in.h>
+		|#include <sys/socket.h>
+		|#include <netdb.h>'
+}
+
+const typemap = {
+	'SocketType':   ['SOCK_']
+	'SocketLevel':  ['SOL_', 'IPPROTO_']
+	'SocketOption': ['SO_', 'IP_', 'IPV6_']
+	'AddrFamily':   ['AF_']
+	'AddrInfoFlag': ['AI_']
+	'NameInfoFlag': ['NI_']
+	'MsgFlag':      ['MSG_']
+}
+
+const vprogram = r'module main
+
+%includes
+
+fn main() {
+	// Generate the final .v file
+	println("module netio\n")
+	println("/*")
+	println("\tThis file is generated by make.vsh, DO NOT EDIT.")
+	println("*/\n")
+	for k, v in cdefs {
+		println("pub const ${k} = ${v.vtype}(${v.value})")
+	}
+}
+
+struct CDef {
+	vtype string
+	value isize
+}
+'
+
+const cc = 'cc'
+const cflags = os.getenv('CFLAGS')
+
+fn main() {
+	cprogram :=
+		cincludes[os.uname().sysname] or { panic('platform is not yet supported') }.strip_margin().trim_space()
+	cc_cmd := "echo '${cprogram}' | ${cc} -x c - -E -dM ${cflags} | sort -k 2 -V"
+	cc_out := os.execute_or_panic(cc_cmd)
+	mut buf := strings.new_builder(1024)
+	buf.writeln(vprogram.replace('%includes', cprogram))
+	buf.writeln('const cdefs = {')
+	for line in cc_out.output.split_into_lines() {
+		for vtype, cdef_prefixes in typemap {
+			for cdef_prefix in cdef_prefixes {
+				if line.starts_with('#define ${cdef_prefix}') {
+					cconst_name := line.fields()[1]
+					if cconst_name.contains('(') {
+						continue // skip non-constant macros
+					}
+					buf.writeln("'${cconst_name.to_lower_ascii()}': CDef{'${vtype}', C.${cconst_name}}")
+				}
+			}
+		}
+	}
+	buf.write_byte(`}`)
+	vfile_path := os.join_path_single(os.temp_dir(), rand.string(10) + '.c.v')
+	os.write_file(vfile_path, buf.str())!
+	os.execute_or_panic('v -Wfatal-errors -W -N ${vfile_path}')
+	os.execute_or_panic('v fmt -w ${vfile_path}')
+	v_out := os.execute_or_panic('${vfile_path.replace('.c.v', '')}')
+	print(v_out.output)
+	flush_stdout()
+	os.rm(vfile_path)!
+}