bindata/main.go

187 lines
4.5 KiB
Go

// This work is subject to the CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
// license. Its contents can be found at:
// http://creativecommons.org/publicdomain/zero/1.0/
package main
import (
"flag"
"fmt"
"os"
"path"
"path/filepath"
"regexp"
"strings"
"unicode"
)
var (
pipe = false
in = ""
out = flag.String("out", "", "Optional path to the output directory.")
pkgname = flag.String("pkg", "main", "Name of the package to generate.")
funcname = flag.String("func", "", "Optional name of the function to generate.")
prefix = flag.String("prefix", "", "Optional path prefix to strip off map keys and function names.")
uncompressed = flag.Bool("uncompressed", false, "The specified resource will /not/ be GZIP compressed when this flag is specified. This alters the generated output code.")
nomemcopy = flag.Bool("nomemcopy", false, "Use a .rodata hack to get rid of unnecessary memcopies. Refer to the documentation to see what implications this carries.")
toc = flag.Bool("toc", false, "Generate a table of contents for this and other files. The input filepath becomes the map key. This option is only useable in non-pipe mode.")
version = flag.Bool("version", false, "Display version information.")
regFuncName = regexp.MustCompile(`[^a-zA-Z0-9_]`)
)
func main() {
parseArgs()
if pipe {
translate(os.Stdin, os.Stdout, *pkgname, *funcname, *uncompressed, *nomemcopy)
return
}
fs, err := os.Open(in)
if err != nil {
fmt.Fprintf(os.Stderr, "[e] %s\n", err)
return
}
defer fs.Close()
fd, err := os.Create(*out)
if err != nil {
fmt.Fprintf(os.Stderr, "[e] %s\n", err)
return
}
defer fd.Close()
// Translate binary to Go code.
translate(fs, fd, *pkgname, *funcname, *uncompressed, *nomemcopy)
// Append the TOC init function to the end of the output file and
// write the `bindata-toc.go` file, if applicable.
if *toc {
err := createTOC(*out, *pkgname)
if err != nil {
fmt.Fprintf(os.Stderr, "[e] %s\n", err)
return
}
writeTOCInit(fd, in, *prefix, *funcname)
}
}
// parseArgs processes and verifies commandline arguments.
func parseArgs() {
flag.Usage = func() {
fmt.Printf("Usage: %s [options] <filename>\n\n", os.Args[0])
flag.PrintDefaults()
}
flag.Parse()
if *version {
fmt.Printf("%s\n", Version())
os.Exit(0)
}
pipe = flag.NArg() == 0
if !pipe {
*prefix, _ = filepath.Abs(filepath.Clean(*prefix))
in, _ = filepath.Abs(filepath.Clean(flag.Args()[0]))
*out = safeFilename(*out, in)
}
if len(*pkgname) == 0 {
fmt.Fprintln(os.Stderr, "[w] No package name specified. Using 'main'.")
*pkgname = "main"
} else {
if unicode.IsDigit(rune((*pkgname)[0])) {
// Identifier can't start with a digit.
*pkgname = "_" + *pkgname
}
}
if len(*funcname) == 0 {
if pipe {
// Can't infer from input file name in this mode.
fmt.Fprintln(os.Stderr, "[e] No function name specified.")
os.Exit(1)
}
*funcname = safeFuncname(in, *prefix)
fmt.Fprintf(os.Stderr, "[w] No function name specified. Using %s.\n", *funcname)
}
}
// safeFilename creates a safe output filename from the given
// output base directory and input filename.
func safeFilename(out, in string) string {
dir, in := filepath.Split(in)
if len(out) == 0 {
out = dir
} else {
out, _ = filepath.Abs(filepath.Clean(out))
}
// Ensure output directory exists while we're here.
stat, err := os.Lstat(out)
if err != nil {
os.MkdirAll(out, 0755)
} else if !stat.IsDir() {
fmt.Fprintf(os.Stderr, "Output path is an existing file.\n")
os.Exit(1)
}
filename := path.Join(out, in+".go")
_, err = os.Lstat(filename)
if err == nil {
// File already exists. Pad name with a sequential number until we
// find a name that is available.
count := 0
for {
filename = path.Join(out, fmt.Sprintf("%s.%d.go", in, count))
_, err = os.Lstat(filename)
if err != nil {
break
}
count++
}
}
return filename
}
// safeFuncname creates a safe function name from the input path.
func safeFuncname(in, prefix string) string {
name := strings.Replace(in, prefix, "", 1)
if len(name) == 0 {
name = in
}
name = strings.ToLower(name)
name = regFuncName.ReplaceAllString(name, "_")
if unicode.IsDigit(rune(name[0])) {
// Identifier can't start with a digit.
name = "_" + name
}
// Get rid of "__" instances for niceness.
for strings.Index(name, "__") > -1 {
name = strings.Replace(name, "__", "_", -1)
}
// Leading underscore is silly.
if name[0] == '_' {
name = name[1:]
}
return name
}