syncthing/vendor/github.com/klauspost/cpuid/private-gen.go

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// +build ignore
package main
import (
"bytes"
"fmt"
"go/ast"
"go/parser"
"go/printer"
"go/token"
"io"
"io/ioutil"
"log"
"os"
"reflect"
"strings"
"unicode"
"unicode/utf8"
)
var inFiles = []string{"cpuid.go", "cpuid_test.go"}
var copyFiles = []string{"cpuid_amd64.s", "cpuid_386.s", "detect_ref.go", "detect_intel.go"}
var fileSet = token.NewFileSet()
var reWrites = []rewrite{
initRewrite("CPUInfo -> cpuInfo"),
initRewrite("Vendor -> vendor"),
initRewrite("Flags -> flags"),
initRewrite("Detect -> detect"),
initRewrite("CPU -> cpu"),
}
var excludeNames = map[string]bool{"string": true, "join": true, "trim": true,
// cpuid_test.go
"t": true, "println": true, "logf": true, "log": true, "fatalf": true, "fatal": true,
}
var excludePrefixes = []string{"test", "benchmark"}
func main() {
Package := "private"
parserMode := parser.ParseComments
exported := make(map[string]rewrite)
for _, file := range inFiles {
in, err := os.Open(file)
if err != nil {
log.Fatalf("opening input", err)
}
src, err := ioutil.ReadAll(in)
if err != nil {
log.Fatalf("reading input", err)
}
astfile, err := parser.ParseFile(fileSet, file, src, parserMode)
if err != nil {
log.Fatalf("parsing input", err)
}
for _, rw := range reWrites {
astfile = rw(astfile)
}
// Inspect the AST and print all identifiers and literals.
var startDecl token.Pos
var endDecl token.Pos
ast.Inspect(astfile, func(n ast.Node) bool {
var s string
switch x := n.(type) {
case *ast.Ident:
if x.IsExported() {
t := strings.ToLower(x.Name)
for _, pre := range excludePrefixes {
if strings.HasPrefix(t, pre) {
return true
}
}
if excludeNames[t] != true {
//if x.Pos() > startDecl && x.Pos() < endDecl {
exported[x.Name] = initRewrite(x.Name + " -> " + t)
}
}
case *ast.GenDecl:
if x.Tok == token.CONST && x.Lparen > 0 {
startDecl = x.Lparen
endDecl = x.Rparen
// fmt.Printf("Decl:%s -> %s\n", fileSet.Position(startDecl), fileSet.Position(endDecl))
}
}
if s != "" {
fmt.Printf("%s:\t%s\n", fileSet.Position(n.Pos()), s)
}
return true
})
for _, rw := range exported {
astfile = rw(astfile)
}
var buf bytes.Buffer
printer.Fprint(&buf, fileSet, astfile)
// Remove package documentation and insert information
s := buf.String()
ind := strings.Index(buf.String(), "\npackage cpuid")
s = s[ind:]
s = "// Generated, DO NOT EDIT,\n" +
"// but copy it to your own project and rename the package.\n" +
"// See more at http://github.com/klauspost/cpuid\n" +
s
outputName := Package + string(os.PathSeparator) + file
err = ioutil.WriteFile(outputName, []byte(s), 0644)
if err != nil {
log.Fatalf("writing output: %s", err)
}
log.Println("Generated", outputName)
}
for _, file := range copyFiles {
dst := ""
if strings.HasPrefix(file, "cpuid") {
dst = Package + string(os.PathSeparator) + file
} else {
dst = Package + string(os.PathSeparator) + "cpuid_" + file
}
err := copyFile(file, dst)
if err != nil {
log.Fatalf("copying file: %s", err)
}
log.Println("Copied", dst)
}
}
// CopyFile copies a file from src to dst. If src and dst files exist, and are
// the same, then return success. Copy the file contents from src to dst.
func copyFile(src, dst string) (err error) {
sfi, err := os.Stat(src)
if err != nil {
return
}
if !sfi.Mode().IsRegular() {
// cannot copy non-regular files (e.g., directories,
// symlinks, devices, etc.)
return fmt.Errorf("CopyFile: non-regular source file %s (%q)", sfi.Name(), sfi.Mode().String())
}
dfi, err := os.Stat(dst)
if err != nil {
if !os.IsNotExist(err) {
return
}
} else {
if !(dfi.Mode().IsRegular()) {
return fmt.Errorf("CopyFile: non-regular destination file %s (%q)", dfi.Name(), dfi.Mode().String())
}
if os.SameFile(sfi, dfi) {
return
}
}
err = copyFileContents(src, dst)
return
}
// copyFileContents copies the contents of the file named src to the file named
// by dst. The file will be created if it does not already exist. If the
// destination file exists, all it's contents will be replaced by the contents
// of the source file.
func copyFileContents(src, dst string) (err error) {
in, err := os.Open(src)
if err != nil {
return
}
defer in.Close()
out, err := os.Create(dst)
if err != nil {
return
}
defer func() {
cerr := out.Close()
if err == nil {
err = cerr
}
}()
if _, err = io.Copy(out, in); err != nil {
return
}
err = out.Sync()
return
}
type rewrite func(*ast.File) *ast.File
// Mostly copied from gofmt
func initRewrite(rewriteRule string) rewrite {
f := strings.Split(rewriteRule, "->")
if len(f) != 2 {
fmt.Fprintf(os.Stderr, "rewrite rule must be of the form 'pattern -> replacement'\n")
os.Exit(2)
}
pattern := parseExpr(f[0], "pattern")
replace := parseExpr(f[1], "replacement")
return func(p *ast.File) *ast.File { return rewriteFile(pattern, replace, p) }
}
// parseExpr parses s as an expression.
// It might make sense to expand this to allow statement patterns,
// but there are problems with preserving formatting and also
// with what a wildcard for a statement looks like.
func parseExpr(s, what string) ast.Expr {
x, err := parser.ParseExpr(s)
if err != nil {
fmt.Fprintf(os.Stderr, "parsing %s %s at %s\n", what, s, err)
os.Exit(2)
}
return x
}
// Keep this function for debugging.
/*
func dump(msg string, val reflect.Value) {
fmt.Printf("%s:\n", msg)
ast.Print(fileSet, val.Interface())
fmt.Println()
}
*/
// rewriteFile applies the rewrite rule 'pattern -> replace' to an entire file.
func rewriteFile(pattern, replace ast.Expr, p *ast.File) *ast.File {
cmap := ast.NewCommentMap(fileSet, p, p.Comments)
m := make(map[string]reflect.Value)
pat := reflect.ValueOf(pattern)
repl := reflect.ValueOf(replace)
var rewriteVal func(val reflect.Value) reflect.Value
rewriteVal = func(val reflect.Value) reflect.Value {
// don't bother if val is invalid to start with
if !val.IsValid() {
return reflect.Value{}
}
for k := range m {
delete(m, k)
}
val = apply(rewriteVal, val)
if match(m, pat, val) {
val = subst(m, repl, reflect.ValueOf(val.Interface().(ast.Node).Pos()))
}
return val
}
r := apply(rewriteVal, reflect.ValueOf(p)).Interface().(*ast.File)
r.Comments = cmap.Filter(r).Comments() // recreate comments list
return r
}
// set is a wrapper for x.Set(y); it protects the caller from panics if x cannot be changed to y.
func set(x, y reflect.Value) {
// don't bother if x cannot be set or y is invalid
if !x.CanSet() || !y.IsValid() {
return
}
defer func() {
if x := recover(); x != nil {
if s, ok := x.(string); ok &&
(strings.Contains(s, "type mismatch") || strings.Contains(s, "not assignable")) {
// x cannot be set to y - ignore this rewrite
return
}
panic(x)
}
}()
x.Set(y)
}
// Values/types for special cases.
var (
objectPtrNil = reflect.ValueOf((*ast.Object)(nil))
scopePtrNil = reflect.ValueOf((*ast.Scope)(nil))
identType = reflect.TypeOf((*ast.Ident)(nil))
objectPtrType = reflect.TypeOf((*ast.Object)(nil))
positionType = reflect.TypeOf(token.NoPos)
callExprType = reflect.TypeOf((*ast.CallExpr)(nil))
scopePtrType = reflect.TypeOf((*ast.Scope)(nil))
)
// apply replaces each AST field x in val with f(x), returning val.
// To avoid extra conversions, f operates on the reflect.Value form.
func apply(f func(reflect.Value) reflect.Value, val reflect.Value) reflect.Value {
if !val.IsValid() {
return reflect.Value{}
}
// *ast.Objects introduce cycles and are likely incorrect after
// rewrite; don't follow them but replace with nil instead
if val.Type() == objectPtrType {
return objectPtrNil
}
// similarly for scopes: they are likely incorrect after a rewrite;
// replace them with nil
if val.Type() == scopePtrType {
return scopePtrNil
}
switch v := reflect.Indirect(val); v.Kind() {
case reflect.Slice:
for i := 0; i < v.Len(); i++ {
e := v.Index(i)
set(e, f(e))
}
case reflect.Struct:
for i := 0; i < v.NumField(); i++ {
e := v.Field(i)
set(e, f(e))
}
case reflect.Interface:
e := v.Elem()
set(v, f(e))
}
return val
}
func isWildcard(s string) bool {
rune, size := utf8.DecodeRuneInString(s)
return size == len(s) && unicode.IsLower(rune)
}
// match returns true if pattern matches val,
// recording wildcard submatches in m.
// If m == nil, match checks whether pattern == val.
func match(m map[string]reflect.Value, pattern, val reflect.Value) bool {
// Wildcard matches any expression. If it appears multiple
// times in the pattern, it must match the same expression
// each time.
if m != nil && pattern.IsValid() && pattern.Type() == identType {
name := pattern.Interface().(*ast.Ident).Name
if isWildcard(name) && val.IsValid() {
// wildcards only match valid (non-nil) expressions.
if _, ok := val.Interface().(ast.Expr); ok && !val.IsNil() {
if old, ok := m[name]; ok {
return match(nil, old, val)
}
m[name] = val
return true
}
}
}
// Otherwise, pattern and val must match recursively.
if !pattern.IsValid() || !val.IsValid() {
return !pattern.IsValid() && !val.IsValid()
}
if pattern.Type() != val.Type() {
return false
}
// Special cases.
switch pattern.Type() {
case identType:
// For identifiers, only the names need to match
// (and none of the other *ast.Object information).
// This is a common case, handle it all here instead
// of recursing down any further via reflection.
p := pattern.Interface().(*ast.Ident)
v := val.Interface().(*ast.Ident)
return p == nil && v == nil || p != nil && v != nil && p.Name == v.Name
case objectPtrType, positionType:
// object pointers and token positions always match
return true
case callExprType:
// For calls, the Ellipsis fields (token.Position) must
// match since that is how f(x) and f(x...) are different.
// Check them here but fall through for the remaining fields.
p := pattern.Interface().(*ast.CallExpr)
v := val.Interface().(*ast.CallExpr)
if p.Ellipsis.IsValid() != v.Ellipsis.IsValid() {
return false
}
}
p := reflect.Indirect(pattern)
v := reflect.Indirect(val)
if !p.IsValid() || !v.IsValid() {
return !p.IsValid() && !v.IsValid()
}
switch p.Kind() {
case reflect.Slice:
if p.Len() != v.Len() {
return false
}
for i := 0; i < p.Len(); i++ {
if !match(m, p.Index(i), v.Index(i)) {
return false
}
}
return true
case reflect.Struct:
for i := 0; i < p.NumField(); i++ {
if !match(m, p.Field(i), v.Field(i)) {
return false
}
}
return true
case reflect.Interface:
return match(m, p.Elem(), v.Elem())
}
// Handle token integers, etc.
return p.Interface() == v.Interface()
}
// subst returns a copy of pattern with values from m substituted in place
// of wildcards and pos used as the position of tokens from the pattern.
// if m == nil, subst returns a copy of pattern and doesn't change the line
// number information.
func subst(m map[string]reflect.Value, pattern reflect.Value, pos reflect.Value) reflect.Value {
if !pattern.IsValid() {
return reflect.Value{}
}
// Wildcard gets replaced with map value.
if m != nil && pattern.Type() == identType {
name := pattern.Interface().(*ast.Ident).Name
if isWildcard(name) {
if old, ok := m[name]; ok {
return subst(nil, old, reflect.Value{})
}
}
}
if pos.IsValid() && pattern.Type() == positionType {
// use new position only if old position was valid in the first place
if old := pattern.Interface().(token.Pos); !old.IsValid() {
return pattern
}
return pos
}
// Otherwise copy.
switch p := pattern; p.Kind() {
case reflect.Slice:
v := reflect.MakeSlice(p.Type(), p.Len(), p.Len())
for i := 0; i < p.Len(); i++ {
v.Index(i).Set(subst(m, p.Index(i), pos))
}
return v
case reflect.Struct:
v := reflect.New(p.Type()).Elem()
for i := 0; i < p.NumField(); i++ {
v.Field(i).Set(subst(m, p.Field(i), pos))
}
return v
case reflect.Ptr:
v := reflect.New(p.Type()).Elem()
if elem := p.Elem(); elem.IsValid() {
v.Set(subst(m, elem, pos).Addr())
}
return v
case reflect.Interface:
v := reflect.New(p.Type()).Elem()
if elem := p.Elem(); elem.IsValid() {
v.Set(subst(m, elem, pos))
}
return v
}
return pattern
}