compiler: cache modules

compiler/cc.v

@@ -63,11 +63,12 @@ fn (v mut V) cc() {
 		v.out_name = v.out_name + '.so'
 	}
 	if v.pref.build_mode == .build_module {
-		// Create the modules directory if it's not there.
+		// Create the modules & out directory if it's not there.
-		if !os.file_exists(v_modules_path)  {
+		out_dir := v_modules_path + v.dir
-			os.mkdir(v_modules_path)
+		if !os.dir_exists(out_dir) {
+			os.mkdir(out_dir)
 		}
-		v.out_name = v_modules_path + v.dir + '.o' //v.out_name
+		v.out_name = '${out_dir}.o' //v.out_name
 		println('Building ${v.out_name}...')
 	}
 

compiler/comptime.v

@@ -117,7 +117,7 @@ fn (p mut Parser) comp_time() {
 		// Parse the function and embed resulting C code in current function so that
 		// all variables are available.
 		pos := p.cgen.lines.len - 1
-		mut pp := p.v.new_parser_file('.vwebtmpl.v')
+		mut pp := p.v.new_parser_from_file('.vwebtmpl.v')
 		if !p.pref.is_debug {
 			os.rm('.vwebtmpl.v')
 		}
@@ -279,7 +279,7 @@ fn (p mut Parser) gen_struct_str(typ Type) {
 	for field in typ.fields {
 		sb.writeln('\t$field.name: $' + 'a.${field.name}')
 	}
-	sb.writeln("\n}'")
+	sb.writeln("}'")
 	sb.writeln('}')
 	p.v.vgen_buf.writeln(sb.str())
 	// Need to manually add the definition to `fns` so that it stays

compiler/fn.v

@@ -144,6 +144,7 @@ fn (p mut Parser) is_sig() bool {
 fn (p mut Parser) fn_decl() {
 	p.clear_vars() // clear local vars every time a new fn is started
 	p.fgen('fn ')
+	
 	//defer { p.fgenln('\n') }
 	// If we are in the first pass, create a new function.
 	// In the second pass fetch the one we created.
@@ -426,10 +427,17 @@ fn (p mut Parser) fn_decl() {
 		if !is_c && p.first_pass() {
 			// TODO hack to make Volt compile without -embed_vlib
 			if f.name == 'darwin__nsstring' && p.pref.build_mode == .default_mode {
-				return
+				
-			}
+			} else {
 				p.cgen.fns << fn_decl + ';'
 			}
+		}
+		// Generate .vh header files when building a module
+		/*
+		if p.pref.build_mode == .build_module {
+			p.vh_genln(f.v_definition())
+		}
+		*/
 		return
 	}
 	if p.attr == 'live' && p.pref.is_so {
@@ -1092,11 +1100,6 @@ fn (f &Fn) typ_str() string {
 	return sb.str()
 }
 
-// "fn foo(a int) stirng", for .vh module headers
-fn (f &Fn) v_definition() string {
-	return 'fn '//$f.name(${f.str_args()})'
-}
-
 // f.args => "int a, string b"
 fn (f &Fn) str_args(table &Table) string {
 	mut s := ''

compiler/main.v

@@ -29,7 +29,6 @@ enum BuildMode {
 const (
 	supported_platforms = ['windows', 'mac', 'linux', 'freebsd', 'openbsd',
 		'netbsd', 'dragonfly', 'msvc', 'android', 'js', 'solaris']
-	v_modules_path            = os.home_dir() + '/.vmodules/'
 )
 
 enum OS {
@@ -105,11 +104,11 @@ mut:
 	building_v    bool
 	autofree      bool
 	compress      bool
-	// Skips re-compilation of the builtin module
+	skip_builtin  bool   // Skips re-compilation of the builtin module
 						 // to increase compilation time.
 						 // This is on by default, since a vast majority of users do not
 						 // work on the builtin module itself.
-	skip_builtin bool
+	
 }
 
 fn main() {
@@ -202,9 +201,7 @@ fn main() {
 		}	
 		v.table.fns.free()
 		free(v.table)
-		//for p in parsers {
+		//for p in parsers {}	
-			
-		//}	
 		println('done!')
 	}	
 }
@@ -218,13 +215,22 @@ fn (v mut V) add_parser(parser Parser) {
 	   v.parsers << parser
 }
 
+fn (v mut V) parse(file string, pass Pass) {
+	//println('parse($file, $pass)')
+	for i, p in v.parsers {
+		if p.file_path == file {
+			v.parsers[i].parse(pass)
+			return
+		}	
+	}	
+}
+
 
 fn (v mut V) compile() {
 	// Emily: Stop people on linux from being able to build with msvc
 	if os.user_os() != 'windows' && v.os == .msvc {
 		verror('Cannot build with msvc on ${os.user_os()}')
 	}
-	
 	mut cgen := v.cgen
 	cgen.genln('// Generated by V')
 	if v.pref.is_verbose {
@@ -250,12 +256,7 @@ fn (v mut V) compile() {
 	*/
 	// First pass (declarations)
 	for file in v.files {
-		for i, p in v.parsers {
+		v.parse(file, .decl)
-			if p.file_path == file {
-				v.parsers[i].parse(.decl)
-				break
-			}	
-		}	
 	}
 	// Main pass
 	cgen.pass = Pass.main
@@ -321,12 +322,7 @@ fn (v mut V) compile() {
 	cgen.genln('this line will be replaced with definitions')
 	defs_pos := cgen.lines.len - 1
 	for file in v.files {
-		for i, p in v.parsers {
+		v.parse(file, .main)
-			if p.file_path == file {
-				v.parsers[i].parse(.main)
-				break
-			}	
-		}	
 		//if p.pref.autofree {		p.scanner.text.free()		free(p.scanner)	}
 		// p.g.gen_x64()
 		// Format all files (don't format automatically generated vlib headers)
@@ -334,8 +330,12 @@ fn (v mut V) compile() {
 			// new vfmt is not ready yet
 		}
 	}
+	// Generate .vh if we are building a module
+	if v.pref.build_mode == .build_module {
+		v.generate_vh()
+	}
 	// parse generated V code (str() methods etc)
-	mut vgen_parser := v.new_parser_string(v.vgen_buf.str(), 'vgen')
+	mut vgen_parser := v.new_parser_from_string(v.vgen_buf.str(), 'vgen')
 	// free the string builder which held the generated methods
 	v.vgen_buf.free()
 	vgen_parser.parse(.main)
@@ -573,8 +573,63 @@ fn (v &V) v_files_from_dir(dir string) []string {
 
 // Parses imports, adds necessary libs, and then user files
 fn (v mut V) add_v_files_to_compile() {
+	// Parse builtin imports
+	for file in v.get_builtin_files() {
+		// add builtins first
+		v.files << file
+		mut p := v.new_parser_from_file(file)
+		p.parse(.imports)
+		//if p.pref.autofree {		p.scanner.text.free()		free(p.scanner)	}
+	}
+	// Parse user imports
+	for file in v.get_user_files() {
+		mut p := v.new_parser_from_file(file)
+		p.parse(.imports)
+		//if p.pref.autofree {		p.scanner.text.free()		free(p.scanner)	}
+	}
+	// Parse lib imports
+	v.parse_lib_imports()
+	if v.pref.is_verbose {
+		v.log('imports:')
+		println(v.table.imports)
+	}
+	// resolve deps & add imports in correct order
+	for mod in v.resolve_deps().imports() {
+		// if mod == v.mod { continue }  // Building this module? Skip. TODO it's a hack.
+		if mod == 'main' { continue } // main files will get added last
+		
+		// use cached built module if exists
+		vh_path := '$v_modules_path/${mod}.vh'
+		if os.file_exists(vh_path) {
+			println('using cached module `$mod`: $vh_path')
+			v.files << vh_path
+			continue
+		}
+		// standard module
+		vfiles := v.v_files_from_dir(v.find_module_path(mod))
+		for file in vfiles {
+			v.files << file
+		}
+	}
+	// add remaining main files last
+	for _, fit in v.table.file_imports {
+		if fit.module_name != 'main' { continue }
+		v.files << fit.file_path
+	}
+}
+
+// get builtin files
+fn (v &V) get_builtin_files() []string {
+	$if js {
+		return v.v_files_from_dir('$v.vroot/vlib/builtin/js/')
+	}
+	return v.v_files_from_dir('$v.vroot/vlib/builtin/')
+}
+
+// get user files
+fn (v &V)  get_user_files() []string {
 	mut dir := v.dir
-	v.log('add_v_files($dir)')
+	v.log('get_v_files($dir)')
 	// Need to store user files separately, because they have to be added after libs, but we dont know
 	// which libs need to be added yet
 	mut user_files := []string
@@ -607,46 +662,25 @@ fn (v mut V) add_v_files_to_compile() {
 		v.log('user_files:')
 		println(user_files)
 	}
-	// Parse builtin imports
+	return user_files
-	for file in v.files {
-		mut p := v.new_parser_file(file)
-		p.parse(.imports)
-		//if p.pref.autofree {		p.scanner.text.free()		free(p.scanner)	}
 }
-	// Parse user imports
-	for file in user_files {
-		mut p := v.new_parser_file(file)
-		p.parse(.imports)
-		//if p.pref.autofree {		p.scanner.text.free()		free(p.scanner)	}
-	}
-	// Parse lib imports
-/*
-	if v.pref.build_mode == .default_mode {
-		// strange ( for mod in v.table.imports ) dosent loop all items
-		// for mod in v.table.imports {
-		for i := 0; i < v.table.imports.len; i++ {
-			mod := v.table.imports[i]
-			mod_path := v.module_path(mod)
-			import_path := '$v_modules_path/vlib/$mod_path'
-			vfiles := v.v_files_from_dir(import_path)
-			if vfiles.len == 0 {
-				verror('cannot import module $mod (no .v files in "$import_path")')
-			}
-			// Add all imports referenced by these libs
-			for file in vfiles {
-				mut p := v.new_parser_file(file, Pass.imports)
-				p.parse()
 
-	if p.pref.autofree {		p.scanner.text.free()		free(p.scanner)	}
+// parse deps from already parsed builtin/user files
+fn (v mut V) parse_lib_imports() {
+	mut done_fits := []string
+	for {
+		for _, fit in v.table.file_imports {
+			if fit.file_path in done_fits { continue }
+			v.parse_file_imports(fit)
+			done_fits << fit.file_path
+		}
+		if v.table.file_imports.size == done_fits.len { break}
 	}
 }
-	}
+
-	else {
+// parse imports from file import table
-*/
+fn (v mut V) parse_file_imports(fit &FileImportTable) {
-	// strange ( for mod in v.table.imports ) dosent loop all items
+	for _, mod in fit.imports {
-	// for mod in v.table.imports {
-	for i := 0; i < v.table.imports.len; i++ {
-		mod := v.table.imports[i]
 		import_path := v.find_module_path(mod)
 		vfiles := v.v_files_from_dir(import_path)
 		if vfiles.len == 0 {
@@ -654,7 +688,7 @@ fn (v mut V) add_v_files_to_compile() {
 		}
 		// Add all imports referenced by these libs
 		for file in vfiles {
-			mut p := v.new_parser_file(file)
+			mut p := v.new_parser_from_file(file)
 			p.parse(.imports)
 			if p.import_table.module_name != mod {
 				verror('bad module name: $file was imported as `$mod` but it is defined as module `$p.import_table.module_name`')
@@ -662,65 +696,18 @@ fn (v mut V) add_v_files_to_compile() {
 			//if p.pref.autofree {		p.scanner.text.free()		free(p.scanner)	}
 		}
 	}
-	if v.pref.is_verbose {
-		v.log('imports:')
-		println(v.table.imports)
 }
-	// graph deps
+
+// return resolved dep graph (order deps)
+fn (v &V) resolve_deps() &DepGraph {
 	mut dep_graph := new_dep_graph()
 	dep_graph.from_import_tables(v.table.file_imports)
 	deps_resolved := dep_graph.resolve()
 	if !deps_resolved.acyclic {
 		deps_resolved.display()
-		verror('Import cycle detected')
+		verror('import cycle detected')
-	}
-	// add imports in correct order
-	for mod in deps_resolved.imports() {
-		// Building this module? Skip. TODO it's a hack.
-		if mod == v.mod {
-			continue
-		}
-		mod_path := v.find_module_path(mod)
-		// If we are in default mode, we don't parse vlib .v files, but
-		// header .vh files in
-		// TmpPath/vlib
-		// These were generated by vfmt
-/*
-		if v.pref.build_mode == .default_mode || v.pref.build_mode == .build_module {
-			module_path = '$v_modules_path/vlib/$mod_p'
-		}
-*/
-		if mod == 'builtin' { continue } // builtin files were already added
-		vfiles := v.v_files_from_dir(mod_path)
-		for file in vfiles {
-			if !(file in v.files) {
-				v.files << file
-			}
-		}
-	}
-	// Add remaining user files
-	mut i := 0
-	mut j := 0
-	mut len := -1
-	for _, fit in v.table.file_imports {
-		// Don't add a duplicate; builtin files are always there
-		if fit.file_path in v.files || fit.module_name == 'builtin' {
-			i++
-			continue
-		}
-		if len == -1 {
-			len = i
-		}
-		j++
-		// TODO remove this once imports work with .build
-		if v.pref.build_mode == .build_module && j >= len / 2{
-			break
-		}
-		//println(fit)
-		//println('fit $fit.file_path')
-		v.files << fit.file_path
-		i++
 	}
+	return deps_resolved
 }
 
 fn get_arg(joined_args, arg, def string) string {
@@ -743,15 +730,6 @@ fn get_all_after(joined_args, arg, def string) string {
 	return res
 }
 
-fn (v &V) module_path(mod string) string {
-	// submodule support
-	if mod.contains('.') {
-		//return mod.replace('.', os.PathSeparator)
-		return mod.replace('.', '/')
-	}
-	return mod
-}
-
 fn (v &V) log(s string) {
 	if !v.pref.is_verbose {
 		return
@@ -867,18 +845,7 @@ fn new_v(args[]string) &V {
 		}
 	}
 	//println('OS=$_os')
-	builtin := 'builtin.v'
+
-	builtins := [
-	'array.v',
-	'string.v',
-	'builtin.v',
-	'int.v',
-	'utf8.v',
-	'map.v',
-	'hashmap.v',
-	'option.v',
-	]
-	//println(builtins)
 	// Location of all vlib files
 	vroot := os.dir(os.executable())
 	//println('VROOT=$vroot')
@@ -898,21 +865,6 @@ fn new_v(args[]string) &V {
 	}
 	//println('out_name:$out_name')
 	mut out_name_c := os.realpath( out_name ) + '.tmp.c'
-	mut files := []string
-	// Add builtin files
-	//if !out_name.contains('builtin.o') {
-		for builtin in builtins {
-			mut f := '$vroot/vlib/builtin/$builtin'
-			__ := 1
-			$if js {
-				f = '$vroot/vlib/builtin/js/$builtin'
-			}
-			// In default mode we use precompiled vlib.o, point to .vh files with signatures
-			if build_mode == .default_mode || build_mode == .build_module {
-				//f = '$TmpPath/vlib/builtin/${builtin}h'
-			}
-			files << f
-		}
 
 	cflags := get_cmdline_cflags(args)
 
@@ -954,7 +906,6 @@ fn new_v(args[]string) &V {
 	return &V{
 		os: _os
 		out_name: out_name
-		files: files
 		dir: dir
 		lang_dir: vroot
 		table: new_table(obfuscate)

compiler/module_header.v

@@ -0,0 +1,201 @@
+// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module main
+
+import (
+	strings
+	os
+)
+
+/* .vh generation logic.
+ .vh files contains only function signatures, consts, and types.
+ They are used together with pre-compiled modules.
+*/
+
+// "fn foo(a int) string"
+fn (f &Fn) v_definition() string {
+	//t :=time.ticks()
+	mut sb := strings.new_builder(100)
+	if f.is_public {
+		sb.write('pub ')
+	}	
+	sb.write('fn ')
+	if f.is_c {
+		sb.write('C.')
+	}	
+	if f.is_method {
+		recv := f.args[0]
+		typ := v_type_str(recv.typ)
+		mut mu := if recv.is_mut { 'mut' } else { '' }
+		if recv.ref {
+			mu = '&'
+		}	
+		sb.write('($recv.name $mu $typ) ')
+	}	
+	if f.name.contains('__') {
+		sb.write(f.name.all_after('__') + '(')
+	} else {
+		sb.write('$f.name(')
+	}
+	for i, arg in f.args {
+		typ := v_type_str(arg.typ)
+		if arg.name == '' {
+			sb.write(typ)
+		}	 else {
+			sb.write('$arg.name $typ')
+		}
+		if i != f.args.len - 1 {
+			sb.write(', ')
+		}
+	}
+	sb.write(')')
+	if f.typ != 'void' {
+		typ := v_type_str(f.typ)
+		sb.write(' ')
+		sb.write(typ)
+		sb.writeln(' ')
+	}
+	//println('ms: ${time.ticks() - t}')
+	return sb.str()
+}
+
+fn v_type_str(typ_ string) string {
+	typ := if typ_.ends_with('*') {
+		'*' + typ_.left(typ_.len - 1)
+	} else {
+		typ_
+	}	
+	//println('"$typ"')
+	if typ == '*void' {
+		return 'voidptr'
+	}	
+	if typ == '*byte' {
+		return 'byteptr'
+	}	
+	if typ.starts_with('array_') {
+		return '[]' + typ.right(6)
+	}	
+	if typ.contains('__') {
+		return typ.all_after('__')
+	}	
+	return typ.replace('Option_', '?')
+}	
+
+fn (v &V) generate_vh() {
+	println('Generating a V header file for module `$v.mod`')
+	dir := v_modules_path + v.mod
+	path := dir + '.vh'
+	if !os.dir_exists(dir) {
+		os.mkdir(dir)
+	}
+	println(path)
+	
+	file := os.create(path) or { panic(err) }
+	// Consts
+	file.writeln('// $v.mod module header \n')
+	file.writeln('// Consts')
+	if v.table.consts.len > 0 {
+		file.writeln('const (')
+		for i, c in v.table.consts {
+			if c.mod != v.mod {
+				continue
+			}	
+			println('$i $c.name')
+			//if !c.name.contains('__') {
+				//continue
+			//}
+			name := c.name.all_after('__')
+			typ := v_type_str(c.typ)
+			file.writeln('\t$name $typ')
+		}	
+		file.writeln(')\n')
+		// Globals
+		for var in v.table.consts {
+			if var.mod != v.mod {
+				continue
+			}	
+			if !var.is_global {
+				continue
+			}	
+			name := var.name.all_after('__')
+			typ := v_type_str(var.typ)
+			file.writeln('__global $name $typ')
+		}
+		file.writeln('\n')
+	}
+	// Types
+	file.writeln('// Types')
+	for _, typ in v.table.typesmap {
+		if typ.mod != v.mod {
+			continue
+		}	
+		if typ.name.contains('__') {
+			continue
+		}	
+		if typ.cat == .struct_ {
+			file.writeln('struct $typ.name {')
+			// Private fields
+			for field in typ.fields {
+				if field.access_mod == .public {
+					continue
+				}	
+				field_type := v_type_str(field.typ)
+				file.writeln('\t$field.name $field_type')
+			}	
+			file.writeln('pub:')
+			for field in typ.fields {
+				if field.access_mod == .private {
+					continue
+				}	
+				field_type := v_type_str(field.typ)
+				file.writeln('\t$field.name $field_type')
+			}	
+			file.writeln('}\n')
+		}
+	}	
+	// Functions & methods
+	file.writeln('// Functions')
+	// Public first
+	mut fns := []Fn
+	// TODO fns := v.table.fns.filter(.mod == v.mod)
+	for _, f in v.table.fns {
+		if f.mod == v.mod {
+			fns << f
+		}	
+	}
+	for _, f in fns {
+		if !f.is_public {
+			continue
+		}	
+		file.writeln(f.v_definition())
+	}	
+	// Private
+	for _, f in fns {
+		if f.is_public {
+			continue
+		}	
+		file.writeln(f.v_definition())
+	}	
+	// Methods
+	file.writeln('\n// Methods //////////////////')
+	for _, typ in v.table.typesmap {
+		if typ.mod != v.mod {
+			continue
+		}	
+		for method in typ.methods {
+			file.writeln(method.v_definition())
+		}	
+	}	
+	file.close()
+	
+	/*
+	for i, p in v.parsers {
+		if v.parsers[i].vh_lines.len > 0 {
+			os.write_file(p.file_name +'.vh', v.parsers[i].vh_lines.join('\n'))
+		}
+	}	
+	*/
+}	
+

compiler/modules.v

@@ -6,6 +6,10 @@ module main
 
 import os
 
+const (
+	v_modules_path = os.home_dir() + '/.vmodules/'
+)
+
 // add a module and its deps (module speficic dag method)
 pub fn(graph mut DepGraph) from_import_tables(import_tables map[string]FileImportTable) {
 	for _, fit in import_tables {
@@ -21,14 +25,20 @@ pub fn(graph mut DepGraph) from_import_tables(import_tables map[string]FileImpor
 pub fn(graph &DepGraph) imports() []string {
 	mut mods := []string
 	for node in graph.nodes {
-		if node.name == 'main' {
-			continue
-		}
 		mods << node.name
 	}
 	return mods
 }
 
+fn (v &V) module_path(mod string) string {
+	// submodule support
+	if mod.contains('.') {
+		//return mod.replace('.', os.PathSeparator)
+		return mod.replace('.', '/')
+	}
+	return mod
+}
+
 // 'strings' => 'VROOT/vlib/strings'
 // 'installed_mod' => '~/.vmodules/installed_mod'
 // 'local_mod' => '/path/to/current/dir/local_mod'

compiler/parser.v

@@ -96,7 +96,7 @@ const (
 
 // new parser from string. unique id specified in `id`.
 // tip: use a hashing function to auto generate `id` from `text` eg. sha1.hexhash(text)
-fn (v mut V) new_parser_string(text string, id string) Parser {
+fn (v mut V) new_parser_from_string(text string, id string) Parser {
 	mut p := v.new_parser(new_scanner(text), id)
 	p.scan_tokens()
 	v.add_parser(p)
@@ -104,7 +104,7 @@ fn (v mut V) new_parser_string(text string, id string) Parser {
 }
 
 // new parser from file.
-fn (v mut V) new_parser_file(path string) Parser {
+fn (v mut V) new_parser_from_file(path string) Parser {
 	//println('new_parser("$path")')
 	mut path_pcguard := ''
 	mut path_platform := '.v'
@@ -505,7 +505,9 @@ fn (p mut Parser) const_decl() {
 		if p.first_pass()  && p.table.known_const(name) {
 			p.error('redefinition of `$name`')
 		}
+		if p.first_pass() {
 			p.table.register_const(name, typ, p.mod)
+		}
 		if p.pass == .main {
 			// TODO hack
 			// cur_line has const's value right now. if it's just a number, then optimize generation:
@@ -898,6 +900,7 @@ if p.scanner.line_comment != '' {
 }
 
 
+[inline]
 fn (p &Parser) first_pass() bool {
 	return p.pass == .decl
 }
@@ -1221,6 +1224,7 @@ fn (p mut Parser) gen(s string) {
 
 // Generate V header from V source
 fn (p mut Parser) vh_genln(s string) {
+	//println('vh $s')
 	p.vh_lines << s
 }
 

vlib/builtin/builtin.v

@@ -9,7 +9,6 @@ fn C.memmove(byteptr, byteptr, int)
 //fn C.malloc(int) byteptr
 fn C.realloc(byteptr, int) byteptr
 
-
 pub fn exit(code int) {
 	C.exit(code)
 }

vlib/builtin/string.v

@@ -69,7 +69,7 @@ fn todo() { }
 // String data is reused, not copied.
 pub fn tos(s byteptr, len int) string {
 	// This should never happen.
-	if isnil(s) {
+	if s == 0 {
 		panic('tos(): nil string')
 	}
 	return string {
@@ -79,7 +79,7 @@ pub fn tos(s byteptr, len int) string {
 }
 
 pub fn tos_clone(s byteptr) string {
-	if isnil(s) {
+	if s == 0 {
 		panic('tos: nil string')
 	}
 	return tos2(s).clone()
@@ -88,12 +88,23 @@ pub fn tos_clone(s byteptr) string {
 // Same as `tos`, but calculates the length. Called by `string(bytes)` casts.
 // Used only internally.
 fn tos2(s byteptr) string {
-	if isnil(s) {
+	if s == 0 {
 		panic('tos2: nil string')
 	}
-	len := vstrlen(s)
+	return string {
-	res := tos(s, len)
+		str: s
-	return res
+		len: vstrlen(s)
+	}
+}
+
+fn tos3(s *C.char) string {
+	if s == 0 {
+		panic('tos3: nil string')
+	}
+	return string {
+		str: byteptr(s)
+		len: C.strlen(s)
+	}
 }
 
 pub fn (a string) clone() string {