336 lines
		
	
	
		
			9.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
		
		
			
		
	
	
			336 lines
		
	
	
		
			9.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
|  | // 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_solaris.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") | ||
|  | 	tags = flag.String("tags", "", "build tags") | ||
|  | ) | ||
|  | 
 | ||
|  | // cmdLine returns this programs's commandline arguments | ||
|  | func cmdLine() string { | ||
|  | 	return "go run mksyscall_solaris.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_solaris.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*)$`).FindStringSubmatch(p) | ||
|  | 	if ps == nil { | ||
|  | 		fmt.Fprintf(os.Stderr, "malformed parameter: %s\n", p) | ||
|  | 		os.Exit(1) | ||
|  | 	} | ||
|  | 	return Param{ps[1], ps[2]} | ||
|  | } | ||
|  | 
 | ||
|  | func main() { | ||
|  | 	flag.Usage = usage | ||
|  | 	flag.Parse() | ||
|  | 	if len(flag.Args()) <= 0 { | ||
|  | 		fmt.Fprintf(os.Stderr, "no files to parse provided\n") | ||
|  | 		usage() | ||
|  | 	} | ||
|  | 
 | ||
|  | 	endianness := "" | ||
|  | 	if *b32 { | ||
|  | 		endianness = "big-endian" | ||
|  | 	} else if *l32 { | ||
|  | 		endianness = "little-endian" | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pack := "" | ||
|  | 	text := "" | ||
|  | 	dynimports := "" | ||
|  | 	linknames := "" | ||
|  | 	var vars []string | ||
|  | 	for _, path := range flag.Args() { | ||
|  | 		file, err := os.Open(path) | ||
|  | 		if err != nil { | ||
|  | 			fmt.Fprintf(os.Stderr, err.Error()) | ||
|  | 			os.Exit(1) | ||
|  | 		} | ||
|  | 		s := bufio.NewScanner(file) | ||
|  | 		for s.Scan() { | ||
|  | 			t := s.Text() | ||
|  | 			t = strings.TrimSpace(t) | ||
|  | 			t = regexp.MustCompile(`\s+`).ReplaceAllString(t, ` `) | ||
|  | 			if p := regexp.MustCompile(`^package (\S+)$`).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" | ||
|  | 
 | ||
|  | 			// So file name. | ||
|  | 			if modname == "" { | ||
|  | 				modname = "libc" | ||
|  | 			} | ||
|  | 
 | ||
|  | 			// System call name. | ||
|  | 			if sysname == "" { | ||
|  | 				sysname = funct | ||
|  | 			} | ||
|  | 
 | ||
|  | 			// System call pointer variable name. | ||
|  | 			sysvarname := fmt.Sprintf("proc%s", sysname) | ||
|  | 
 | ||
|  | 			strconvfunc := "BytePtrFromString" | ||
|  | 			strconvtype := "*byte" | ||
|  | 
 | ||
|  | 			sysname = strings.ToLower(sysname) // All libc functions are lowercase. | ||
|  | 
 | ||
|  | 			// Runtime import of function to allow cross-platform builds. | ||
|  | 			dynimports += fmt.Sprintf("//go:cgo_import_dynamic libc_%s %s \"%s.so\"\n", sysname, sysname, modname) | ||
|  | 			// Link symbol to proc address variable. | ||
|  | 			linknames += fmt.Sprintf("//go:linkname %s libc_%s\n", sysvarname, sysname) | ||
|  | 			// Library proc address variable. | ||
|  | 			vars = append(vars, sysvarname) | ||
|  | 
 | ||
|  | 			// Go function header. | ||
|  | 			outlist := strings.Join(out, ", ") | ||
|  | 			if outlist != "" { | ||
|  | 				outlist = fmt.Sprintf(" (%s)", outlist) | ||
|  | 			} | ||
|  | 			if text != "" { | ||
|  | 				text += "\n" | ||
|  | 			} | ||
|  | 			text += fmt.Sprintf("func %s(%s)%s {\n", funct, strings.Join(in, ", "), outlist) | ||
|  | 
 | ||
|  | 			// Check if err return available | ||
|  | 			errvar := "" | ||
|  | 			for _, param := range out { | ||
|  | 				p := parseParam(param) | ||
|  | 				if p.Type == "error" { | ||
|  | 					errvar = p.Name | ||
|  | 					continue | ||
|  | 				} | ||
|  | 			} | ||
|  | 
 | ||
|  | 			// 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 %s\n", n, strconvtype) | ||
|  | 					text += fmt.Sprintf("\t_p%d, %s = %s(%s)\n", n, errvar, strconvfunc, 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 %s\n", n, strconvtype) | ||
|  | 					text += fmt.Sprintf("\t_p%d, _ = %s(%s)\n", n, strconvfunc, p.Name) | ||
|  | 					args = append(args, fmt.Sprintf("uintptr(unsafe.Pointer(_p%d))", n)) | ||
|  | 					n++ | ||
|  | 				} else if s := regexp.MustCompile(`^\[\](.*)`).FindStringSubmatch(p.Type); s != 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, s[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("uintptr(unsafe.Pointer(_p%d))", n), fmt.Sprintf("uintptr(len(%s))", p.Name)) | ||
|  | 					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)) | ||
|  | 					} | ||
|  | 				} 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("uintptr(_p%d)", n)) | ||
|  | 					n++ | ||
|  | 				} else { | ||
|  | 					args = append(args, fmt.Sprintf("uintptr(%s)", p.Name)) | ||
|  | 				} | ||
|  | 			} | ||
|  | 			nargs := len(args) | ||
|  | 
 | ||
|  | 			// Determine which form to use; pad args with zeros. | ||
|  | 			asm := "sysvicall6" | ||
|  | 			if nonblock != nil { | ||
|  | 				asm = "rawSysvicall6" | ||
|  | 			} | ||
|  | 			if len(args) <= 6 { | ||
|  | 				for len(args) < 6 { | ||
|  | 					args = append(args, "0") | ||
|  | 				} | ||
|  | 			} else { | ||
|  | 				fmt.Fprintf(os.Stderr, "%s: too many arguments to system call\n", path) | ||
|  | 				os.Exit(1) | ||
|  | 			} | ||
|  | 
 | ||
|  | 			// Actual call. | ||
|  | 			arglist := strings.Join(args, ", ") | ||
|  | 			call := fmt.Sprintf("%s(uintptr(unsafe.Pointer(&%s)), %d, %s)", asm, sysvarname, nargs, 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" { | ||
|  | 					reg = "e1" | ||
|  | 					ret[2] = reg | ||
|  | 					doErrno = true | ||
|  | 				} else { | ||
|  | 					reg = fmt.Sprintf("r%d", i) | ||
|  | 					ret[i] = reg | ||
|  | 				} | ||
|  | 				if p.Type == "bool" { | ||
|  | 					reg = fmt.Sprintf("%d != 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: not enough registers for int64 return\n", path) | ||
|  | 						os.Exit(1) | ||
|  | 					} | ||
|  | 					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" { | ||
|  | 					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 { | ||
|  | 				text += fmt.Sprintf("\t%s, %s, %s := %s\n", ret[0], ret[1], ret[2], call) | ||
|  | 			} | ||
|  | 			text += body | ||
|  | 
 | ||
|  | 			if doErrno { | ||
|  | 				text += "\tif e1 != 0 {\n" | ||
|  | 				text += "\t\terr = e1\n" | ||
|  | 				text += "\t}\n" | ||
|  | 			} | ||
|  | 			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" | ||
|  | 
 | ||
|  | 	} | ||
|  | 	vardecls := "\t" + strings.Join(vars, ",\n\t") | ||
|  | 	vardecls += " syscallFunc" | ||
|  | 	fmt.Printf(srcTemplate, cmdLine(), buildTags(), pack, imp, dynimports, linknames, vardecls, text) | ||
|  | } | ||
|  | 
 | ||
|  | const srcTemplate = `// %s | ||
|  | // Code generated by the command above; see README.md. DO NOT EDIT. | ||
|  | 
 | ||
|  | // +build %s | ||
|  | 
 | ||
|  | package %s | ||
|  | 
 | ||
|  | import ( | ||
|  | 	"syscall" | ||
|  | 	"unsafe" | ||
|  | ) | ||
|  | %s | ||
|  | %s | ||
|  | %s | ||
|  | var ( | ||
|  | %s	 | ||
|  | ) | ||
|  | 
 | ||
|  | %s | ||
|  | ` |