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Diffstat (limited to '')
-rw-r--r-- | dependencies/pkg/mod/golang.org/x/sys@v0.1.0/plan9/mksyscall.go | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/plan9/mksyscall.go b/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/plan9/mksyscall.go new file mode 100644 index 0000000..a5062c2 --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/plan9/mksyscall.go @@ -0,0 +1,400 @@ +// Copyright 2018 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. + +//go:build ignore +// +build ignore + +/* +This program reads a file containing function prototypes +(like syscall_plan9.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 errno. + +A line beginning with //sysnb is like //sys, except that the +goroutine will not be suspended during the execution of the system +call. This must only be used for system calls which can never +block, as otherwise the system call could cause all goroutines to +hang. +*/ +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") + plan9 = flag.Bool("plan9", false, "plan9") + openbsd = flag.Bool("openbsd", false, "openbsd") + netbsd = flag.Bool("netbsd", false, "netbsd") + dragonfly = flag.Bool("dragonfly", false, "dragonfly") + arm = flag.Bool("arm", false, "arm") // 64-bit value should use (even, odd)-pair + tags = flag.String("tags", "", "build tags") + filename = flag.String("output", "", "output file name (standard output if omitted)") +) + +// cmdLine returns this programs's commandline arguments +func cmdLine() string { + return "go run mksyscall.go " + strings.Join(os.Args[1:], " ") +} + +// goBuildTags returns build tags in the go:build format. +func goBuildTags() string { + return strings.ReplaceAll(*tags, ",", " && ") +} + +// plusBuildTags returns build tags in the +build format. +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.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() { + // Get the OS and architecture (using GOARCH_TARGET if it exists) + goos := os.Getenv("GOOS") + goarch := os.Getenv("GOARCH_TARGET") + if goarch == "" { + goarch = os.Getenv("GOARCH") + } + + // Check that we are using the Docker-based build system if we should + if goos == "linux" { + if os.Getenv("GOLANG_SYS_BUILD") != "docker" { + fmt.Fprintf(os.Stderr, "In the Docker-based build system, mksyscall should not be called directly.\n") + fmt.Fprintf(os.Stderr, "See README.md\n") + os.Exit(1) + } + } + + 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" + } + + libc := false + if goos == "darwin" && strings.Contains(buildTags(), ",go1.12") { + libc = true + } + trampolines := map[string]bool{} + + text := "" + 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, ` `) + 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, errno error) + // Split into name, in params, out params. + f := regexp.MustCompile(`^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*((?i)SYS_[A-Z0-9_]+))?$`).FindStringSubmatch(t) + if f == nil { + fmt.Fprintf(os.Stderr, "%s:%s\nmalformed //sys declaration\n", path, t) + os.Exit(1) + } + funct, inps, outps, sysname := f[2], f[3], f[4], f[5] + + // Split argument lists on comma. + in := parseParamList(inps) + out := parseParamList(outps) + + // 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" + + // Go function header. + outDecl := "" + if len(out) > 0 { + outDecl = fmt.Sprintf(" (%s)", strings.Join(out, ", ")) + } + text += fmt.Sprintf("func %s(%s)%s {\n", funct, strings.Join(in, ", "), outDecl) + + // Check if err return available + errvar := "" + for _, param := range out { + p := parseParam(param) + if p.Type == "error" { + errvar = p.Name + break + } + } + + // Prepare arguments to Syscall. + var args []string + n := 0 + for _, param := range in { + p := parseParam(param) + if regexp.MustCompile(`^\*`).FindStringSubmatch(p.Type) != nil { + args = append(args, "uintptr(unsafe.Pointer("+p.Name+"))") + } else if p.Type == "string" && errvar != "" { + text += fmt.Sprintf("\tvar _p%d *byte\n", n) + text += fmt.Sprintf("\t_p%d, %s = BytePtrFromString(%s)\n", n, errvar, p.Name) + text += fmt.Sprintf("\tif %s != nil {\n\t\treturn\n\t}\n", errvar) + args = append(args, fmt.Sprintf("uintptr(unsafe.Pointer(_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("\tvar _p%d *byte\n", n) + text += fmt.Sprintf("\t_p%d, _ = BytePtrFromString(%s)\n", n, p.Name) + args = append(args, fmt.Sprintf("uintptr(unsafe.Pointer(_p%d))", n)) + n++ + } else if regexp.MustCompile(`^\[\](.*)`).FindStringSubmatch(p.Type) != nil { + // Convert slice into pointer, length. + // Have to be careful not to take address of &a[0] if len == 0: + // pass dummy pointer in that case. + // Used to pass nil, but some OSes or simulators reject write(fd, nil, 0). + text += fmt.Sprintf("\tvar _p%d unsafe.Pointer\n", n) + text += fmt.Sprintf("\tif len(%s) > 0 {\n\t\t_p%d = unsafe.Pointer(&%s[0])\n\t}", p.Name, n, p.Name) + text += fmt.Sprintf(" else {\n\t\t_p%d = unsafe.Pointer(&_zero)\n\t}\n", n) + args = append(args, fmt.Sprintf("uintptr(_p%d)", n), fmt.Sprintf("uintptr(len(%s))", p.Name)) + n++ + } else if p.Type == "int64" && (*openbsd || *netbsd) { + args = append(args, "0") + if endianness == "big-endian" { + args = append(args, fmt.Sprintf("uintptr(%s>>32)", p.Name), fmt.Sprintf("uintptr(%s)", p.Name)) + } else if endianness == "little-endian" { + args = append(args, fmt.Sprintf("uintptr(%s)", p.Name), fmt.Sprintf("uintptr(%s>>32)", p.Name)) + } else { + args = append(args, fmt.Sprintf("uintptr(%s)", p.Name)) + } + } else if p.Type == "int64" && *dragonfly { + if regexp.MustCompile(`^(?i)extp(read|write)`).FindStringSubmatch(funct) == nil { + args = append(args, "0") + } + if endianness == "big-endian" { + args = append(args, fmt.Sprintf("uintptr(%s>>32)", p.Name), fmt.Sprintf("uintptr(%s)", p.Name)) + } else if endianness == "little-endian" { + args = append(args, fmt.Sprintf("uintptr(%s)", p.Name), fmt.Sprintf("uintptr(%s>>32)", p.Name)) + } else { + args = append(args, fmt.Sprintf("uintptr(%s)", p.Name)) + } + } else if p.Type == "int64" && endianness != "" { + if len(args)%2 == 1 && *arm { + // arm abi specifies 64-bit argument uses + // (even, odd) pair + args = append(args, "0") + } + 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)) + } + } else { + args = append(args, fmt.Sprintf("uintptr(%s)", p.Name)) + } + } + + // Determine which form to use; pad args with zeros. + asm := "Syscall" + if nonblock != nil { + if errvar == "" && goos == "linux" { + asm = "RawSyscallNoError" + } else { + asm = "RawSyscall" + } + } else { + if errvar == "" && goos == "linux" { + asm = "SyscallNoError" + } + } + if len(args) <= 3 { + for len(args) < 3 { + args = append(args, "0") + } + } else if len(args) <= 6 { + asm += "6" + for len(args) < 6 { + args = append(args, "0") + } + } else if len(args) <= 9 { + asm += "9" + for len(args) < 9 { + args = append(args, "0") + } + } else { + fmt.Fprintf(os.Stderr, "%s:%s too many arguments to system call\n", path, funct) + } + + // System call number. + if sysname == "" { + sysname = "SYS_" + funct + sysname = regexp.MustCompile(`([a-z])([A-Z])`).ReplaceAllString(sysname, `${1}_$2`) + sysname = strings.ToUpper(sysname) + } + + var libcFn string + if libc { + asm = "syscall_" + strings.ToLower(asm[:1]) + asm[1:] // internal syscall call + sysname = strings.TrimPrefix(sysname, "SYS_") // remove SYS_ + sysname = strings.ToLower(sysname) // lowercase + if sysname == "getdirentries64" { + // Special case - libSystem name and + // raw syscall name don't match. + sysname = "__getdirentries64" + } + libcFn = sysname + sysname = "funcPC(libc_" + sysname + "_trampoline)" + } + + // Actual call. + arglist := strings.Join(args, ", ") + call := fmt.Sprintf("%s(%s, %s)", asm, sysname, arglist) + + // Assign return values. + body := "" + ret := []string{"_", "_", "_"} + doErrno := false + for i := 0; i < len(out); i++ { + p := parseParam(out[i]) + reg := "" + if p.Name == "err" && !*plan9 { + reg = "e1" + ret[2] = reg + doErrno = true + } else if p.Name == "err" && *plan9 { + ret[0] = "r0" + ret[2] = "e1" + break + } else { + reg = fmt.Sprintf("r%d", i) + ret[i] = reg + } + if p.Type == "bool" { + reg = fmt.Sprintf("%s != 0", reg) + } + if p.Type == "int64" && endianness != "" { + // 64-bit number in r1:r0 or r0:r1. + if i+2 > len(out) { + fmt.Fprintf(os.Stderr, "%s:%s not enough registers for int64 return\n", path, funct) + } + if endianness == "big-endian" { + reg = fmt.Sprintf("int64(r%d)<<32 | int64(r%d)", i, i+1) + } else { + reg = fmt.Sprintf("int64(r%d)<<32 | int64(r%d)", i+1, i) + } + ret[i] = fmt.Sprintf("r%d", i) + ret[i+1] = fmt.Sprintf("r%d", i+1) + } + if reg != "e1" || *plan9 { + body += fmt.Sprintf("\t%s = %s(%s)\n", p.Name, p.Type, reg) + } + } + if ret[0] == "_" && ret[1] == "_" && ret[2] == "_" { + text += fmt.Sprintf("\t%s\n", call) + } else { + if errvar == "" && goos == "linux" { + // raw syscall without error on Linux, see golang.org/issue/22924 + text += fmt.Sprintf("\t%s, %s := %s\n", ret[0], ret[1], call) + } else { + text += fmt.Sprintf("\t%s, %s, %s := %s\n", ret[0], ret[1], ret[2], call) + } + } + text += body + + if *plan9 && ret[2] == "e1" { + text += "\tif int32(r0) == -1 {\n" + text += "\t\terr = e1\n" + text += "\t}\n" + } else if doErrno { + text += "\tif e1 != 0 {\n" + text += "\t\terr = errnoErr(e1)\n" + text += "\t}\n" + } + text += "\treturn\n" + text += "}\n\n" + + if libc && !trampolines[libcFn] { + // some system calls share a trampoline, like read and readlen. + trampolines[libcFn] = true + // Declare assembly trampoline. + text += fmt.Sprintf("func libc_%s_trampoline()\n", libcFn) + // Assembly trampoline calls the libc_* function, which this magic + // redirects to use the function from libSystem. + text += fmt.Sprintf("//go:linkname libc_%s libc_%s\n", libcFn, libcFn) + text += fmt.Sprintf("//go:cgo_import_dynamic libc_%s %s \"/usr/lib/libSystem.B.dylib\"\n", libcFn, libcFn) + text += "\n" + } + } + if err := s.Err(); err != nil { + fmt.Fprintf(os.Stderr, err.Error()) + os.Exit(1) + } + file.Close() + } + fmt.Printf(srcTemplate, cmdLine(), goBuildTags(), plusBuildTags(), text) +} + +const srcTemplate = `// %s +// Code generated by the command above; see README.md. DO NOT EDIT. + +//go:build %s +// +build %s + +package plan9 + +import "unsafe" + +%s +` |