// 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
`