github.com/Andyfoo/golang/x/sys@v0.0.0-20190901054642-57c1bf301704/unix/mksyscall_solaris.go (about) 1 // Copyright 2019 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build ignore 6 7 /* 8 This program reads a file containing function prototypes 9 (like syscall_solaris.go) and generates system call bodies. 10 The prototypes are marked by lines beginning with "//sys" 11 and read like func declarations if //sys is replaced by func, but: 12 * The parameter lists must give a name for each argument. 13 This includes return parameters. 14 * The parameter lists must give a type for each argument: 15 the (x, y, z int) shorthand is not allowed. 16 * If the return parameter is an error number, it must be named err. 17 * If go func name needs to be different than its libc name, 18 * or the function is not in libc, name could be specified 19 * at the end, after "=" sign, like 20 //sys getsockopt(s int, level int, name int, val uintptr, vallen *_Socklen) (err error) = libsocket.getsockopt 21 */ 22 23 package main 24 25 import ( 26 "bufio" 27 "flag" 28 "fmt" 29 "os" 30 "regexp" 31 "strings" 32 ) 33 34 var ( 35 b32 = flag.Bool("b32", false, "32bit big-endian") 36 l32 = flag.Bool("l32", false, "32bit little-endian") 37 tags = flag.String("tags", "", "build tags") 38 ) 39 40 // cmdLine returns this programs's commandline arguments 41 func cmdLine() string { 42 return "go run mksyscall_solaris.go " + strings.Join(os.Args[1:], " ") 43 } 44 45 // buildTags returns build tags 46 func buildTags() string { 47 return *tags 48 } 49 50 // Param is function parameter 51 type Param struct { 52 Name string 53 Type string 54 } 55 56 // usage prints the program usage 57 func usage() { 58 fmt.Fprintf(os.Stderr, "usage: go run mksyscall_solaris.go [-b32 | -l32] [-tags x,y] [file ...]\n") 59 os.Exit(1) 60 } 61 62 // parseParamList parses parameter list and returns a slice of parameters 63 func parseParamList(list string) []string { 64 list = strings.TrimSpace(list) 65 if list == "" { 66 return []string{} 67 } 68 return regexp.MustCompile(`\s*,\s*`).Split(list, -1) 69 } 70 71 // parseParam splits a parameter into name and type 72 func parseParam(p string) Param { 73 ps := regexp.MustCompile(`^(\S*) (\S*)$`).FindStringSubmatch(p) 74 if ps == nil { 75 fmt.Fprintf(os.Stderr, "malformed parameter: %s\n", p) 76 os.Exit(1) 77 } 78 return Param{ps[1], ps[2]} 79 } 80 81 func main() { 82 flag.Usage = usage 83 flag.Parse() 84 if len(flag.Args()) <= 0 { 85 fmt.Fprintf(os.Stderr, "no files to parse provided\n") 86 usage() 87 } 88 89 endianness := "" 90 if *b32 { 91 endianness = "big-endian" 92 } else if *l32 { 93 endianness = "little-endian" 94 } 95 96 pack := "" 97 text := "" 98 dynimports := "" 99 linknames := "" 100 var vars []string 101 for _, path := range flag.Args() { 102 file, err := os.Open(path) 103 if err != nil { 104 fmt.Fprintf(os.Stderr, err.Error()) 105 os.Exit(1) 106 } 107 s := bufio.NewScanner(file) 108 for s.Scan() { 109 t := s.Text() 110 t = strings.TrimSpace(t) 111 t = regexp.MustCompile(`\s+`).ReplaceAllString(t, ` `) 112 if p := regexp.MustCompile(`^package (\S+)$`).FindStringSubmatch(t); p != nil && pack == "" { 113 pack = p[1] 114 } 115 nonblock := regexp.MustCompile(`^\/\/sysnb `).FindStringSubmatch(t) 116 if regexp.MustCompile(`^\/\/sys `).FindStringSubmatch(t) == nil && nonblock == nil { 117 continue 118 } 119 120 // Line must be of the form 121 // func Open(path string, mode int, perm int) (fd int, err error) 122 // Split into name, in params, out params. 123 f := regexp.MustCompile(`^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*(?:(\w*)\.)?(\w*))?$`).FindStringSubmatch(t) 124 if f == nil { 125 fmt.Fprintf(os.Stderr, "%s:%s\nmalformed //sys declaration\n", path, t) 126 os.Exit(1) 127 } 128 funct, inps, outps, modname, sysname := f[2], f[3], f[4], f[5], f[6] 129 130 // Split argument lists on comma. 131 in := parseParamList(inps) 132 out := parseParamList(outps) 133 134 inps = strings.Join(in, ", ") 135 outps = strings.Join(out, ", ") 136 137 // Try in vain to keep people from editing this file. 138 // The theory is that they jump into the middle of the file 139 // without reading the header. 140 text += "// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n\n" 141 142 // So file name. 143 if modname == "" { 144 modname = "libc" 145 } 146 147 // System call name. 148 if sysname == "" { 149 sysname = funct 150 } 151 152 // System call pointer variable name. 153 sysvarname := fmt.Sprintf("proc%s", sysname) 154 155 strconvfunc := "BytePtrFromString" 156 strconvtype := "*byte" 157 158 sysname = strings.ToLower(sysname) // All libc functions are lowercase. 159 160 // Runtime import of function to allow cross-platform builds. 161 dynimports += fmt.Sprintf("//go:cgo_import_dynamic libc_%s %s \"%s.so\"\n", sysname, sysname, modname) 162 // Link symbol to proc address variable. 163 linknames += fmt.Sprintf("//go:linkname %s libc_%s\n", sysvarname, sysname) 164 // Library proc address variable. 165 vars = append(vars, sysvarname) 166 167 // Go function header. 168 outlist := strings.Join(out, ", ") 169 if outlist != "" { 170 outlist = fmt.Sprintf(" (%s)", outlist) 171 } 172 if text != "" { 173 text += "\n" 174 } 175 text += fmt.Sprintf("func %s(%s)%s {\n", funct, strings.Join(in, ", "), outlist) 176 177 // Check if err return available 178 errvar := "" 179 for _, param := range out { 180 p := parseParam(param) 181 if p.Type == "error" { 182 errvar = p.Name 183 continue 184 } 185 } 186 187 // Prepare arguments to Syscall. 188 var args []string 189 n := 0 190 for _, param := range in { 191 p := parseParam(param) 192 if regexp.MustCompile(`^\*`).FindStringSubmatch(p.Type) != nil { 193 args = append(args, "uintptr(unsafe.Pointer("+p.Name+"))") 194 } else if p.Type == "string" && errvar != "" { 195 text += fmt.Sprintf("\tvar _p%d %s\n", n, strconvtype) 196 text += fmt.Sprintf("\t_p%d, %s = %s(%s)\n", n, errvar, strconvfunc, p.Name) 197 text += fmt.Sprintf("\tif %s != nil {\n\t\treturn\n\t}\n", errvar) 198 args = append(args, fmt.Sprintf("uintptr(unsafe.Pointer(_p%d))", n)) 199 n++ 200 } else if p.Type == "string" { 201 fmt.Fprintf(os.Stderr, path+":"+funct+" uses string arguments, but has no error return\n") 202 text += fmt.Sprintf("\tvar _p%d %s\n", n, strconvtype) 203 text += fmt.Sprintf("\t_p%d, _ = %s(%s)\n", n, strconvfunc, p.Name) 204 args = append(args, fmt.Sprintf("uintptr(unsafe.Pointer(_p%d))", n)) 205 n++ 206 } else if s := regexp.MustCompile(`^\[\](.*)`).FindStringSubmatch(p.Type); s != nil { 207 // Convert slice into pointer, length. 208 // Have to be careful not to take address of &a[0] if len == 0: 209 // pass nil in that case. 210 text += fmt.Sprintf("\tvar _p%d *%s\n", n, s[1]) 211 text += fmt.Sprintf("\tif len(%s) > 0 {\n\t\t_p%d = &%s[0]\n\t}\n", p.Name, n, p.Name) 212 args = append(args, fmt.Sprintf("uintptr(unsafe.Pointer(_p%d))", n), fmt.Sprintf("uintptr(len(%s))", p.Name)) 213 n++ 214 } else if p.Type == "int64" && endianness != "" { 215 if endianness == "big-endian" { 216 args = append(args, fmt.Sprintf("uintptr(%s>>32)", p.Name), fmt.Sprintf("uintptr(%s)", p.Name)) 217 } else { 218 args = append(args, fmt.Sprintf("uintptr(%s)", p.Name), fmt.Sprintf("uintptr(%s>>32)", p.Name)) 219 } 220 } else if p.Type == "bool" { 221 text += fmt.Sprintf("\tvar _p%d uint32\n", n) 222 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) 223 args = append(args, fmt.Sprintf("uintptr(_p%d)", n)) 224 n++ 225 } else { 226 args = append(args, fmt.Sprintf("uintptr(%s)", p.Name)) 227 } 228 } 229 nargs := len(args) 230 231 // Determine which form to use; pad args with zeros. 232 asm := "sysvicall6" 233 if nonblock != nil { 234 asm = "rawSysvicall6" 235 } 236 if len(args) <= 6 { 237 for len(args) < 6 { 238 args = append(args, "0") 239 } 240 } else { 241 fmt.Fprintf(os.Stderr, "%s: too many arguments to system call\n", path) 242 os.Exit(1) 243 } 244 245 // Actual call. 246 arglist := strings.Join(args, ", ") 247 call := fmt.Sprintf("%s(uintptr(unsafe.Pointer(&%s)), %d, %s)", asm, sysvarname, nargs, arglist) 248 249 // Assign return values. 250 body := "" 251 ret := []string{"_", "_", "_"} 252 doErrno := false 253 for i := 0; i < len(out); i++ { 254 p := parseParam(out[i]) 255 reg := "" 256 if p.Name == "err" { 257 reg = "e1" 258 ret[2] = reg 259 doErrno = true 260 } else { 261 reg = fmt.Sprintf("r%d", i) 262 ret[i] = reg 263 } 264 if p.Type == "bool" { 265 reg = fmt.Sprintf("%d != 0", reg) 266 } 267 if p.Type == "int64" && endianness != "" { 268 // 64-bit number in r1:r0 or r0:r1. 269 if i+2 > len(out) { 270 fmt.Fprintf(os.Stderr, "%s: not enough registers for int64 return\n", path) 271 os.Exit(1) 272 } 273 if endianness == "big-endian" { 274 reg = fmt.Sprintf("int64(r%d)<<32 | int64(r%d)", i, i+1) 275 } else { 276 reg = fmt.Sprintf("int64(r%d)<<32 | int64(r%d)", i+1, i) 277 } 278 ret[i] = fmt.Sprintf("r%d", i) 279 ret[i+1] = fmt.Sprintf("r%d", i+1) 280 } 281 if reg != "e1" { 282 body += fmt.Sprintf("\t%s = %s(%s)\n", p.Name, p.Type, reg) 283 } 284 } 285 if ret[0] == "_" && ret[1] == "_" && ret[2] == "_" { 286 text += fmt.Sprintf("\t%s\n", call) 287 } else { 288 text += fmt.Sprintf("\t%s, %s, %s := %s\n", ret[0], ret[1], ret[2], call) 289 } 290 text += body 291 292 if doErrno { 293 text += "\tif e1 != 0 {\n" 294 text += "\t\terr = e1\n" 295 text += "\t}\n" 296 } 297 text += "\treturn\n" 298 text += "}\n" 299 } 300 if err := s.Err(); err != nil { 301 fmt.Fprintf(os.Stderr, err.Error()) 302 os.Exit(1) 303 } 304 file.Close() 305 } 306 imp := "" 307 if pack != "unix" { 308 imp = "import \"github.com/Andyfoo/golang/x/sys/unix\"\n" 309 310 } 311 vardecls := "\t" + strings.Join(vars, ",\n\t") 312 vardecls += " syscallFunc" 313 fmt.Printf(srcTemplate, cmdLine(), buildTags(), pack, imp, dynimports, linknames, vardecls, text) 314 } 315 316 const srcTemplate = `// %s 317 // Code generated by the command above; see README.md. DO NOT EDIT. 318 319 // +build %s 320 321 package %s 322 323 import ( 324 "syscall" 325 "unsafe" 326 ) 327 %s 328 %s 329 %s 330 var ( 331 %s 332 ) 333 334 %s 335 `