unix/mksyscall_aix_ppc.go - sys - Git at Google

 // Copyright 2019 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 // +build ignore

 /*
 This program reads a file containing function prototypes
 (like syscall_aix.go) and generates system call bodies.
 The prototypes are marked by lines beginning with "//sys"
 and read like func declarations if //sys is replaced by func, but:
 	* The parameter lists must give a name for each argument.
 	  This includes return parameters.
 	* The parameter lists must give a type for each argument:
 	  the (x, y, z int) shorthand is not allowed.
 	* If the return parameter is an error number, it must be named err.
 	* If go func name needs to be different than its libc name,
 	* or the function is not in libc, name could be specified
 	* at the end, after "=" sign, like
 	  //sys getsockopt(s int, level int, name int, val uintptr, vallen *_Socklen) (err error) = libsocket.getsockopt
 */
 package main

 import (
 	"bufio"
 	"flag"
 	"fmt"
 	"os"
 	"regexp"
 	"strings"
 )

 var (
 	b32  = flag.Bool("b32", false, "32bit big-endian")
 	l32  = flag.Bool("l32", false, "32bit little-endian")
 	aix  = flag.Bool("aix", false, "aix")
 	tags = flag.String("tags", "", "build tags")
 )

 // cmdLine returns this programs's commandline arguments
 func cmdLine() string {
 	return "go run mksyscall_aix_ppc.go " + strings.Join(os.Args[1:], " ")
 }

 // buildTags returns build tags
 func buildTags() string {
 	return *tags
 }

 // Param is function parameter
 type Param struct {
 	Name string
 	Type string
 }

 // usage prints the program usage
 func usage() {
 	fmt.Fprintf(os.Stderr, "usage: go run mksyscall_aix_ppc.go [-b32 | -l32] [-tags x,y] [file ...]\n")
 	os.Exit(1)
 }

 // parseParamList parses parameter list and returns a slice of parameters
 func parseParamList(list string) []string {
 	list = strings.TrimSpace(list)
 	if list == "" {
 		return []string{}
 	}
 	return regexp.MustCompile(`\s*,\s*`).Split(list, -1)
 }

 // parseParam splits a parameter into name and type
 func parseParam(p string) Param {
 	ps := regexp.MustCompile(`^(\S*) (\S*)$`).FindStringSubmatch(p)
 	if ps == nil {
 		fmt.Fprintf(os.Stderr, "malformed parameter: %s\n", p)
 		os.Exit(1)
 	}
 	return Param{ps[1], ps[2]}
 }

 func main() {
 	flag.Usage = usage
 	flag.Parse()
 	if len(flag.Args()) <= 0 {
 		fmt.Fprintf(os.Stderr, "no files to parse provided\n")
 		usage()
 	}

 	endianness := ""
 	if *b32 {
 		endianness = "big-endian"
 	} else if *l32 {
 		endianness = "little-endian"
 	}

 	pack := ""
 	text := ""
 	cExtern := "/*\n#include <stdint.h>\n#include <stddef.h>\n"
 	for _, path := range flag.Args() {
 		file, err := os.Open(path)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, err.Error())
 			os.Exit(1)
 		}
 		s := bufio.NewScanner(file)
 		for s.Scan() {
 			t := s.Text()
 			t = strings.TrimSpace(t)
 			t = regexp.MustCompile(`\s+`).ReplaceAllString(t, ` `)
 			if p := regexp.MustCompile(`^package (\S+)$`).FindStringSubmatch(t); p != nil && pack == "" {
 				pack = p[1]
 			}
 			nonblock := regexp.MustCompile(`^\/\/sysnb `).FindStringSubmatch(t)
 			if regexp.MustCompile(`^\/\/sys `).FindStringSubmatch(t) == nil && nonblock == nil {
 				continue
 			}

 			// Line must be of the form
 			//	func Open(path string, mode int, perm int) (fd int, err error)
 			// Split into name, in params, out params.
 			f := regexp.MustCompile(`^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*(?:(\w*)\.)?(\w*))?$`).FindStringSubmatch(t)
 			if f == nil {
 				fmt.Fprintf(os.Stderr, "%s:%s\nmalformed //sys declaration\n", path, t)
 				os.Exit(1)
 			}
 			funct, inps, outps, modname, sysname := f[2], f[3], f[4], f[5], f[6]

 			// Split argument lists on comma.
 			in := parseParamList(inps)
 			out := parseParamList(outps)

 			inps = strings.Join(in, ", ")
 			outps = strings.Join(out, ", ")

 			// Try in vain to keep people from editing this file.
 			// The theory is that they jump into the middle of the file
 			// without reading the header.
 			text += "// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n\n"

 			// Check if value return, err return available
 			errvar := ""
 			retvar := ""
 			rettype := ""
 			for _, param := range out {
 				p := parseParam(param)
 				if p.Type == "error" {
 					errvar = p.Name
 				} else {
 					retvar = p.Name
 					rettype = p.Type
 				}
 			}

 			// System call name.
 			if sysname == "" {
 				sysname = funct
 			}
 			sysname = regexp.MustCompile(`([a-z])([A-Z])`).ReplaceAllString(sysname, `${1}_$2`)
 			sysname = strings.ToLower(sysname) // All libc functions are lowercase.

 			cRettype := ""
 			if rettype == "unsafe.Pointer" {
 				cRettype = "uintptr_t"
 			} else if rettype == "uintptr" {
 				cRettype = "uintptr_t"
 			} else if regexp.MustCompile(`^_`).FindStringSubmatch(rettype) != nil {
 				cRettype = "uintptr_t"
 			} else if rettype == "int" {
 				cRettype = "int"
 			} else if rettype == "int32" {
 				cRettype = "int"
 			} else if rettype == "int64" {
 				cRettype = "long long"
 			} else if rettype == "uint32" {
 				cRettype = "unsigned int"
 			} else if rettype == "uint64" {
 				cRettype = "unsigned long long"
 			} else {
 				cRettype = "int"
 			}
 			if sysname == "exit" {
 				cRettype = "void"
 			}

 			// Change p.Types to c
 			var cIn []string
 			for _, param := range in {
 				p := parseParam(param)
 				if regexp.MustCompile(`^\*`).FindStringSubmatch(p.Type) != nil {
 					cIn = append(cIn, "uintptr_t")
 				} else if p.Type == "string" {
 					cIn = append(cIn, "uintptr_t")
 				} else if regexp.MustCompile(`^\[\](.*)`).FindStringSubmatch(p.Type) != nil {
 					cIn = append(cIn, "uintptr_t", "size_t")
 				} else if p.Type == "unsafe.Pointer" {
 					cIn = append(cIn, "uintptr_t")
 				} else if p.Type == "uintptr" {
 					cIn = append(cIn, "uintptr_t")
 				} else if regexp.MustCompile(`^_`).FindStringSubmatch(p.Type) != nil {
 					cIn = append(cIn, "uintptr_t")
 				} else if p.Type == "int" {
 					cIn = append(cIn, "int")
 				} else if p.Type == "int32" {
 					cIn = append(cIn, "int")
 				} else if p.Type == "int64" {
 					cIn = append(cIn, "long long")
 				} else if p.Type == "uint32" {
 					cIn = append(cIn, "unsigned int")
 				} else if p.Type == "uint64" {
 					cIn = append(cIn, "unsigned long long")
 				} else {
 					cIn = append(cIn, "int")
 				}
 			}

 			if funct != "fcntl" && funct != "FcntlInt" && funct != "readlen" && funct != "writelen" {
 				if sysname == "select" {
 					// select is a keyword of Go. Its name is
 					// changed to c_select.
 					cExtern += "#define c_select select\n"
 				}
 				// Imports of system calls from libc
 				cExtern += fmt.Sprintf("%s %s", cRettype, sysname)
 				cIn := strings.Join(cIn, ", ")
 				cExtern += fmt.Sprintf("(%s);\n", cIn)
 			}

 			// So file name.
 			if *aix {
 				if modname == "" {
 					modname = "libc.a/shr_64.o"
 				} else {
 					fmt.Fprintf(os.Stderr, "%s: only syscall using libc are available\n", funct)
 					os.Exit(1)
 				}
 			}

 			strconvfunc := "C.CString"

 			// Go function header.
 			if outps != "" {
 				outps = fmt.Sprintf(" (%s)", outps)
 			}
 			if text != "" {
 				text += "\n"
 			}

 			text += fmt.Sprintf("func %s(%s)%s {\n", funct, strings.Join(in, ", "), outps)

 			// Prepare arguments to Syscall.
 			var args []string
 			n := 0
 			argN := 0
 			for _, param := range in {
 				p := parseParam(param)
 				if regexp.MustCompile(`^\*`).FindStringSubmatch(p.Type) != nil {
 					args = append(args, "C.uintptr_t(uintptr(unsafe.Pointer("+p.Name+")))")
 				} else if p.Type == "string" && errvar != "" {
 					text += fmt.Sprintf("\t_p%d := uintptr(unsafe.Pointer(%s(%s)))\n", n, strconvfunc, p.Name)
 					args = append(args, fmt.Sprintf("C.uintptr_t(_p%d)", n))
 					n++
 				} else if p.Type == "string" {
 					fmt.Fprintf(os.Stderr, path+":"+funct+" uses string arguments, but has no error return\n")
 					text += fmt.Sprintf("\t_p%d := uintptr(unsafe.Pointer(%s(%s)))\n", n, strconvfunc, p.Name)
 					args = append(args, fmt.Sprintf("C.uintptr_t(_p%d)", n))
 					n++
 				} else if m := regexp.MustCompile(`^\[\](.*)`).FindStringSubmatch(p.Type); m != nil {
 					// Convert slice into pointer, length.
 					// Have to be careful not to take address of &a[0] if len == 0:
 					// pass nil in that case.
 					text += fmt.Sprintf("\tvar _p%d *%s\n", n, m[1])
 					text += fmt.Sprintf("\tif len(%s) > 0 {\n\t\t_p%d = &%s[0]\n\t}\n", p.Name, n, p.Name)
 					args = append(args, fmt.Sprintf("C.uintptr_t(uintptr(unsafe.Pointer(_p%d)))", n))
 					n++
 					text += fmt.Sprintf("\tvar _p%d int\n", n)
 					text += fmt.Sprintf("\t_p%d = len(%s)\n", n, p.Name)
 					args = append(args, fmt.Sprintf("C.size_t(_p%d)", n))
 					n++
 				} else if p.Type == "int64" && endianness != "" {
 					if endianness == "big-endian" {
 						args = append(args, fmt.Sprintf("uintptr(%s>>32)", p.Name), fmt.Sprintf("uintptr(%s)", p.Name))
 					} else {
 						args = append(args, fmt.Sprintf("uintptr(%s)", p.Name), fmt.Sprintf("uintptr(%s>>32)", p.Name))
 					}
 					n++
 				} else if p.Type == "bool" {
 					text += fmt.Sprintf("\tvar _p%d uint32\n", n)
 					text += fmt.Sprintf("\tif %s {\n\t\t_p%d = 1\n\t} else {\n\t\t_p%d = 0\n\t}\n", p.Name, n, n)
 					args = append(args, fmt.Sprintf("_p%d", n))
 				} else if regexp.MustCompile(`^_`).FindStringSubmatch(p.Type) != nil {
 					args = append(args, fmt.Sprintf("C.uintptr_t(uintptr(%s))", p.Name))
 				} else if p.Type == "unsafe.Pointer" {
 					args = append(args, fmt.Sprintf("C.uintptr_t(uintptr(%s))", p.Name))
 				} else if p.Type == "int" {
 					if (argN == 2) && ((funct == "readlen") || (funct == "writelen")) {
 						args = append(args, fmt.Sprintf("C.size_t(%s)", p.Name))
 					} else if argN == 0 && funct == "fcntl" {
 						args = append(args, fmt.Sprintf("C.uintptr_t(%s)", p.Name))
 					} else if (argN == 2) && ((funct == "fcntl") || (funct == "FcntlInt")) {
 						args = append(args, fmt.Sprintf("C.uintptr_t(%s)", p.Name))
 					} else {
 						args = append(args, fmt.Sprintf("C.int(%s)", p.Name))
 					}
 				} else if p.Type == "int32" {
 					args = append(args, fmt.Sprintf("C.int(%s)", p.Name))
 				} else if p.Type == "int64" {
 					args = append(args, fmt.Sprintf("C.longlong(%s)", p.Name))
 				} else if p.Type == "uint32" {
 					args = append(args, fmt.Sprintf("C.uint(%s)", p.Name))
 				} else if p.Type == "uint64" {
 					args = append(args, fmt.Sprintf("C.ulonglong(%s)", p.Name))
 				} else if p.Type == "uintptr" {
 					args = append(args, fmt.Sprintf("C.uintptr_t(%s)", p.Name))
 				} else {
 					args = append(args, fmt.Sprintf("C.int(%s)", p.Name))
 				}
 				argN++
 			}

 			// Actual call.
 			arglist := strings.Join(args, ", ")
 			call := ""
 			if sysname == "exit" {
 				if errvar != "" {
 					call += "er :="
 				} else {
 					call += ""
 				}
 			} else if errvar != "" {
 				call += "r0,er :="
 			} else if retvar != "" {
 				call += "r0,_ :="
 			} else {
 				call += ""
 			}
 			if sysname == "select" {
 				// select is a keyword of Go. Its name is
 				// changed to c_select.
 				call += fmt.Sprintf("C.c_%s(%s)", sysname, arglist)
 			} else {
 				call += fmt.Sprintf("C.%s(%s)", sysname, arglist)
 			}

 			// Assign return values.
 			body := ""
 			for i := 0; i < len(out); i++ {
 				p := parseParam(out[i])
 				reg := ""
 				if p.Name == "err" {
 					reg = "e1"
 				} else {
 					reg = "r0"
 				}
 				if reg != "e1" {
 					body += fmt.Sprintf("\t%s = %s(%s)\n", p.Name, p.Type, reg)
 				}
 			}

 			// verify return
 			if sysname != "exit" && errvar != "" {
 				if regexp.MustCompile(`^uintptr`).FindStringSubmatch(cRettype) != nil {
 					body += "\tif (uintptr(r0) ==^uintptr(0) && er != nil) {\n"
 					body += fmt.Sprintf("\t\t%s = er\n", errvar)
 					body += "\t}\n"
 				} else {
 					body += "\tif (r0 ==-1 && er != nil) {\n"
 					body += fmt.Sprintf("\t\t%s = er\n", errvar)
 					body += "\t}\n"
 				}
 			} else if errvar != "" {
 				body += "\tif (er != nil) {\n"
 				body += fmt.Sprintf("\t\t%s = er\n", errvar)
 				body += "\t}\n"
 			}

 			text += fmt.Sprintf("\t%s\n", call)
 			text += body

 			text += "\treturn\n"
 			text += "}\n"
 		}
 		if err := s.Err(); err != nil {
 			fmt.Fprintf(os.Stderr, err.Error())
 			os.Exit(1)
 		}
 		file.Close()
 	}
 	imp := ""
 	if pack != "unix" {
 		imp = "import \"golang.org/x/sys/unix\"\n"

 	}
 	fmt.Printf(srcTemplate, cmdLine(), buildTags(), pack, cExtern, imp, text)
 }

 const srcTemplate = `// %s
 // Code generated by the command above; see README.md. DO NOT EDIT.

 // +build %s

 package %s


 %s
 */
 import "C"
 import (
 	"unsafe"
 )


 %s

 %s
 `
	// Copyright 2019 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	// +build ignore

	/*
	This program reads a file containing function prototypes
	(like syscall_aix.go) and generates system call bodies.
	The prototypes are marked by lines beginning with "//sys"
	and read like func declarations if //sys is replaced by func, but:
	* The parameter lists must give a name for each argument.
	This includes return parameters.
	* The parameter lists must give a type for each argument:
	the (x, y, z int) shorthand is not allowed.
	* If the return parameter is an error number, it must be named err.
	* If go func name needs to be different than its libc name,
	* or the function is not in libc, name could be specified
	* at the end, after "=" sign, like
	//sys getsockopt(s int, level int, name int, val uintptr, vallen *_Socklen) (err error) = libsocket.getsockopt
	*/
	package main

	import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"regexp"
	"strings"
	)

	var (
	b32 = flag.Bool("b32", false, "32bit big-endian")
	l32 = flag.Bool("l32", false, "32bit little-endian")
	aix = flag.Bool("aix", false, "aix")
	tags = flag.String("tags", "", "build tags")
	)

	// cmdLine returns this programs's commandline arguments
	func cmdLine() string {
	return "go run mksyscall_aix_ppc.go " + strings.Join(os.Args[1:], " ")
	}

	// buildTags returns build tags
	func buildTags() string {
	return *tags
	}

	// Param is function parameter
	type Param struct {
	Name string
	Type string
	}

	// usage prints the program usage
	func usage() {
	fmt.Fprintf(os.Stderr, "usage: go run mksyscall_aix_ppc.go [-b32 \| -l32] [-tags x,y] [file ...]\n")
	os.Exit(1)
	}

	// parseParamList parses parameter list and returns a slice of parameters
	func parseParamList(list string) []string {
	list = strings.TrimSpace(list)
	if list == "" {
	return []string{}
	}
	return regexp.MustCompile(`\s,\s`).Split(list, -1)
	}

	// parseParam splits a parameter into name and type
	func parseParam(p string) Param {
	ps := regexp.MustCompile(`^(\S) (\S)$`).FindStringSubmatch(p)
	if ps == nil {
	fmt.Fprintf(os.Stderr, "malformed parameter: %s\n", p)
	os.Exit(1)
	}
	return Param{ps[1], ps[2]}
	}

	func main() {
	flag.Usage = usage
	flag.Parse()
	if len(flag.Args()) <= 0 {
	fmt.Fprintf(os.Stderr, "no files to parse provided\n")
	usage()
	}

	endianness := ""
	if *b32 {
	endianness = "big-endian"
	} else if *l32 {
	endianness = "little-endian"
	}

	pack := ""
	text := ""
	cExtern := "/*\n#include <stdint.h>\n#include <stddef.h>\n"
	for _, path := range flag.Args() {
	file, err := os.Open(path)
	if err != nil {
	fmt.Fprintf(os.Stderr, err.Error())
	os.Exit(1)
	}
	s := bufio.NewScanner(file)
	for s.Scan() {
	t := s.Text()
	t = strings.TrimSpace(t)
	t = regexp.MustCompile(`\s+`).ReplaceAllString(t, ` `)
	if p := regexp.MustCompile(`^package (\S+)$`).FindStringSubmatch(t); p != nil && pack == "" {
	pack = p[1]
	}
	nonblock := regexp.MustCompile(`^\/\/sysnb `).FindStringSubmatch(t)
	if regexp.MustCompile(`^\/\/sys `).FindStringSubmatch(t) == nil && nonblock == nil {
	continue
	}

	// Line must be of the form
	// func Open(path string, mode int, perm int) (fd int, err error)
	// Split into name, in params, out params.
	f := regexp.MustCompile(`^\/\/sys(nb)? (\w+)\(([^()])\)\s(?:\(([^()]+)\))?\s(?:=\s(?:(\w)\.)?(\w))?$`).FindStringSubmatch(t)
	if f == nil {
	fmt.Fprintf(os.Stderr, "%s:%s\nmalformed //sys declaration\n", path, t)
	os.Exit(1)
	}
	funct, inps, outps, modname, sysname := f[2], f[3], f[4], f[5], f[6]

	// Split argument lists on comma.
	in := parseParamList(inps)
	out := parseParamList(outps)

	inps = strings.Join(in, ", ")
	outps = strings.Join(out, ", ")

	// Try in vain to keep people from editing this file.
	// The theory is that they jump into the middle of the file
	// without reading the header.
	text += "// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n\n"

	// Check if value return, err return available
	errvar := ""
	retvar := ""
	rettype := ""
	for _, param := range out {
	p := parseParam(param)
	if p.Type == "error" {
	errvar = p.Name
	} else {
	retvar = p.Name
	rettype = p.Type
	}
	}

	// System call name.
	if sysname == "" {
	sysname = funct
	}
	sysname = regexp.MustCompile(`([a-z])([A-Z])`).ReplaceAllString(sysname, `${1}_$2`)
	sysname = strings.ToLower(sysname) // All libc functions are lowercase.

	cRettype := ""
	if rettype == "unsafe.Pointer" {
	cRettype = "uintptr_t"
	} else if rettype == "uintptr" {
	cRettype = "uintptr_t"
	} else if regexp.MustCompile(`^_`).FindStringSubmatch(rettype) != nil {
	cRettype = "uintptr_t"
	} else if rettype == "int" {
	cRettype = "int"
	} else if rettype == "int32" {
	cRettype = "int"
	} else if rettype == "int64" {
	cRettype = "long long"
	} else if rettype == "uint32" {
	cRettype = "unsigned int"
	} else if rettype == "uint64" {
	cRettype = "unsigned long long"
	} else {
	cRettype = "int"
	}
	if sysname == "exit" {
	cRettype = "void"
	}

	// Change p.Types to c
	var cIn []string
	for _, param := range in {
	p := parseParam(param)
	if regexp.MustCompile(`^\*`).FindStringSubmatch(p.Type) != nil {
	cIn = append(cIn, "uintptr_t")
	} else if p.Type == "string" {
	cIn = append(cIn, "uintptr_t")
	} else if regexp.MustCompile(`^\[\](.*)`).FindStringSubmatch(p.Type) != nil {
	cIn = append(cIn, "uintptr_t", "size_t")
	} else if p.Type == "unsafe.Pointer" {
	cIn = append(cIn, "uintptr_t")
	} else if p.Type == "uintptr" {
	cIn = append(cIn, "uintptr_t")
	} else if regexp.MustCompile(`^_`).FindStringSubmatch(p.Type) != nil {
	cIn = append(cIn, "uintptr_t")
	} else if p.Type == "int" {
	cIn = append(cIn, "int")
	} else if p.Type == "int32" {
	cIn = append(cIn, "int")
	} else if p.Type == "int64" {
	cIn = append(cIn, "long long")
	} else if p.Type == "uint32" {
	cIn = append(cIn, "unsigned int")
	} else if p.Type == "uint64" {
	cIn = append(cIn, "unsigned long long")
	} else {
	cIn = append(cIn, "int")
	}
	}

	if funct != "fcntl" && funct != "FcntlInt" && funct != "readlen" && funct != "writelen" {
	if sysname == "select" {
	// select is a keyword of Go. Its name is
	// changed to c_select.
	cExtern += "#define c_select select\n"
	}
	// Imports of system calls from libc
	cExtern += fmt.Sprintf("%s %s", cRettype, sysname)
	cIn := strings.Join(cIn, ", ")
	cExtern += fmt.Sprintf("(%s);\n", cIn)
	}

	// So file name.
	if *aix {
	if modname == "" {
	modname = "libc.a/shr_64.o"
	} else {
	fmt.Fprintf(os.Stderr, "%s: only syscall using libc are available\n", funct)
	os.Exit(1)
	}
	}

	strconvfunc := "C.CString"

	// Go function header.
	if outps != "" {
	outps = fmt.Sprintf(" (%s)", outps)
	}
	if text != "" {
	text += "\n"
	}

	text += fmt.Sprintf("func %s(%s)%s {\n", funct, strings.Join(in, ", "), outps)

	// Prepare arguments to Syscall.
	var args []string
	n := 0
	argN := 0
	for _, param := range in {
	p := parseParam(param)
	if regexp.MustCompile(`^\*`).FindStringSubmatch(p.Type) != nil {
	args = append(args, "C.uintptr_t(uintptr(unsafe.Pointer("+p.Name+")))")
	} else if p.Type == "string" && errvar != "" {
	text += fmt.Sprintf("\t_p%d := uintptr(unsafe.Pointer(%s(%s)))\n", n, strconvfunc, p.Name)
	args = append(args, fmt.Sprintf("C.uintptr_t(_p%d)", n))
	n++
	} else if p.Type == "string" {
	fmt.Fprintf(os.Stderr, path+":"+funct+" uses string arguments, but has no error return\n")
	text += fmt.Sprintf("\t_p%d := uintptr(unsafe.Pointer(%s(%s)))\n", n, strconvfunc, p.Name)
	args = append(args, fmt.Sprintf("C.uintptr_t(_p%d)", n))
	n++
	} else if m := regexp.MustCompile(`^\[\](.*)`).FindStringSubmatch(p.Type); m != nil {
	// Convert slice into pointer, length.
	// Have to be careful not to take address of &a[0] if len == 0:
	// pass nil in that case.
	text += fmt.Sprintf("\tvar _p%d *%s\n", n, m[1])
	text += fmt.Sprintf("\tif len(%s) > 0 {\n\t\t_p%d = &%s[0]\n\t}\n", p.Name, n, p.Name)
	args = append(args, fmt.Sprintf("C.uintptr_t(uintptr(unsafe.Pointer(_p%d)))", n))
	n++
	text += fmt.Sprintf("\tvar _p%d int\n", n)
	text += fmt.Sprintf("\t_p%d = len(%s)\n", n, p.Name)
	args = append(args, fmt.Sprintf("C.size_t(_p%d)", n))
	n++
	} else if p.Type == "int64" && endianness != "" {
	if endianness == "big-endian" {
	args = append(args, fmt.Sprintf("uintptr(%s>>32)", p.Name), fmt.Sprintf("uintptr(%s)", p.Name))
	} else {
	args = append(args, fmt.Sprintf("uintptr(%s)", p.Name), fmt.Sprintf("uintptr(%s>>32)", p.Name))
	}
	n++
	} else if p.Type == "bool" {
	text += fmt.Sprintf("\tvar _p%d uint32\n", n)
	text += fmt.Sprintf("\tif %s {\n\t\t_p%d = 1\n\t} else {\n\t\t_p%d = 0\n\t}\n", p.Name, n, n)
	args = append(args, fmt.Sprintf("_p%d", n))
	} else if regexp.MustCompile(`^_`).FindStringSubmatch(p.Type) != nil {
	args = append(args, fmt.Sprintf("C.uintptr_t(uintptr(%s))", p.Name))
	} else if p.Type == "unsafe.Pointer" {
	args = append(args, fmt.Sprintf("C.uintptr_t(uintptr(%s))", p.Name))
	} else if p.Type == "int" {
	if (argN == 2) && ((funct == "readlen") \|\| (funct == "writelen")) {
	args = append(args, fmt.Sprintf("C.size_t(%s)", p.Name))
	} else if argN == 0 && funct == "fcntl" {
	args = append(args, fmt.Sprintf("C.uintptr_t(%s)", p.Name))
	} else if (argN == 2) && ((funct == "fcntl") \|\| (funct == "FcntlInt")) {
	args = append(args, fmt.Sprintf("C.uintptr_t(%s)", p.Name))
	} else {
	args = append(args, fmt.Sprintf("C.int(%s)", p.Name))
	}
	} else if p.Type == "int32" {
	args = append(args, fmt.Sprintf("C.int(%s)", p.Name))
	} else if p.Type == "int64" {
	args = append(args, fmt.Sprintf("C.longlong(%s)", p.Name))
	} else if p.Type == "uint32" {
	args = append(args, fmt.Sprintf("C.uint(%s)", p.Name))
	} else if p.Type == "uint64" {
	args = append(args, fmt.Sprintf("C.ulonglong(%s)", p.Name))
	} else if p.Type == "uintptr" {
	args = append(args, fmt.Sprintf("C.uintptr_t(%s)", p.Name))
	} else {
	args = append(args, fmt.Sprintf("C.int(%s)", p.Name))
	}
	argN++
	}

	// Actual call.
	arglist := strings.Join(args, ", ")
	call := ""
	if sysname == "exit" {
	if errvar != "" {
	call += "er :="
	} else {
	call += ""
	}
	} else if errvar != "" {
	call += "r0,er :="
	} else if retvar != "" {
	call += "r0,_ :="
	} else {
	call += ""
	}
	if sysname == "select" {
	// select is a keyword of Go. Its name is
	// changed to c_select.
	call += fmt.Sprintf("C.c_%s(%s)", sysname, arglist)
	} else {
	call += fmt.Sprintf("C.%s(%s)", sysname, arglist)
	}

	// Assign return values.
	body := ""
	for i := 0; i < len(out); i++ {
	p := parseParam(out[i])
	reg := ""
	if p.Name == "err" {
	reg = "e1"
	} else {
	reg = "r0"
	}
	if reg != "e1" {
	body += fmt.Sprintf("\t%s = %s(%s)\n", p.Name, p.Type, reg)
	}
	}

	// verify return
	if sysname != "exit" && errvar != "" {
	if regexp.MustCompile(`^uintptr`).FindStringSubmatch(cRettype) != nil {
	body += "\tif (uintptr(r0) ==^uintptr(0) && er != nil) {\n"
	body += fmt.Sprintf("\t\t%s = er\n", errvar)
	body += "\t}\n"
	} else {
	body += "\tif (r0 ==-1 && er != nil) {\n"
	body += fmt.Sprintf("\t\t%s = er\n", errvar)
	body += "\t}\n"
	}
	} else if errvar != "" {
	body += "\tif (er != nil) {\n"
	body += fmt.Sprintf("\t\t%s = er\n", errvar)
	body += "\t}\n"
	}

	text += fmt.Sprintf("\t%s\n", call)
	text += body

	text += "\treturn\n"
	text += "}\n"
	}
	if err := s.Err(); err != nil {
	fmt.Fprintf(os.Stderr, err.Error())
	os.Exit(1)
	}
	file.Close()
	}
	imp := ""
	if pack != "unix" {
	imp = "import \"golang.org/x/sys/unix\"\n"

	}
	fmt.Printf(srcTemplate, cmdLine(), buildTags(), pack, cExtern, imp, text)
	}

	const srcTemplate = `// %s
	// Code generated by the command above; see README.md. DO NOT EDIT.

	// +build %s

	package %s


	%s
	*/
	import "C"
	import (
	"unsafe"
	)


	%s

	%s
	`