// parseOffsetFlag interprets the "-offset" flag value as a renaming specification.
func parseOffsetFlag(ctxt *build.Context, offsetFlag string) (*spec, error) {
var spec spec
// Validate -offset, e.g. file.go:#123
parts := strings.Split(offsetFlag, ":#")
if len(parts) != 2 {
return nil, fmt.Errorf("-offset %q: invalid offset specification", offsetFlag)
}
spec.filename = parts[0]
if !buildutil.FileExists(ctxt, spec.filename) {
return nil, fmt.Errorf("no such file: %s", spec.filename)
}
bp, err := buildutil.ContainingPackage(ctxt, wd, spec.filename)
if err != nil {
return nil, err
}
spec.pkg = bp.ImportPath
for _, r := range parts[1] {
if !isDigit(r) {
return nil, fmt.Errorf("-offset %q: non-numeric offset", offsetFlag)
}
}
spec.offset, err = strconv.Atoi(parts[1])
if err != nil {
return nil, fmt.Errorf("-offset %q: non-numeric offset", offsetFlag)
}
// Parse the file and check there's an identifier at that offset.
fset := token.NewFileSet()
f, err := buildutil.ParseFile(fset, ctxt, nil, wd, spec.filename, parser.ParseComments)
if err != nil {
return nil, fmt.Errorf("-offset %q: cannot parse file: %s", offsetFlag, err)
}
id := identAtOffset(fset, f, spec.offset)
if id == nil {
return nil, fmt.Errorf("-offset %q: no identifier at this position", offsetFlag)
}
spec.fromName = id.Name
return &spec, nil
}
// parseFromFlag interprets the "-from" flag value as a renaming specification.
// See FromFlagUsage for valid formats.
func parseFromFlag(ctxt *build.Context, fromFlag string) (*spec, error) {
var spec spec
var main string // sans "::x" suffix
switch parts := strings.Split(fromFlag, "::"); len(parts) {
case 1:
main = parts[0]
case 2:
main = parts[0]
spec.searchFor = parts[1]
if parts[1] == "" {
// error
}
default:
return nil, fmt.Errorf("-from %q: invalid identifier specification (see -help for formats)", fromFlag)
}
// main is one of:
// filename.go
// importpath
// importpath.member
// (importpath.type).fieldormethod
if strings.HasSuffix(main, ".go") {
// filename.go
if spec.searchFor == "" {
return nil, fmt.Errorf("-from: filename %q must have a ::name suffix", main)
}
spec.filename = main
if !buildutil.FileExists(ctxt, spec.filename) {
return nil, fmt.Errorf("no such file: %s", spec.filename)
}
bp, err := buildutil.ContainingPackage(ctxt, wd, spec.filename)
if err != nil {
return nil, err
}
spec.pkg = bp.ImportPath
} else if a, b := splitAtLastDot(main); b == "" {
// importpath e.g. "encoding/json"
if spec.searchFor == "" {
return nil, fmt.Errorf("-from %q: package import path %q must have a ::name suffix",
main, a)
}
spec.pkg = a
} else if strings.HasPrefix(a, "(") && strings.HasSuffix(a, ")") {
// field/method of type e.g. (encoding/json.Decoder).Decode
c, d := splitAtLastDot(a[1 : len(a)-1])
if d == "" {
return nil, fmt.Errorf("-from %q: not a package-level named type: %q", a)
}
spec.pkg = c // e.g. "encoding/json"
spec.pkgMember = d // e.g. "Decoder"
spec.typeMember = b // e.g. "Decode"
spec.fromName = b
} else {
// package member e.g. "encoding/json.HTMLEscape"
spec.pkg = a // e.g. "encoding/json"
spec.pkgMember = b // e.g. "HTMLEscape"
spec.fromName = b
}
if spec.searchFor != "" {
spec.fromName = spec.searchFor
}
// Sanitize the package.
// TODO(adonovan): test with relative packages. May need loader changes.
bp, err := ctxt.Import(spec.pkg, ".", build.FindOnly)
if err != nil {
return nil, fmt.Errorf("can't find package %q", spec.pkg)
}
spec.pkg = bp.ImportPath
if !isValidIdentifier(spec.fromName) {
return nil, fmt.Errorf("-from: invalid identifier %q", spec.fromName)
}
if Verbose {
fmt.Fprintf(os.Stderr, "-from spec: %+v\n", spec)
}
return &spec, nil
}
// parseFromFlag interprets the "-from" flag value as a renaming specification.
// See FromFlagUsage for valid formats.
func parseFromFlag(ctxt *build.Context, fromFlag string) (*spec, error) {
var spec spec
var main string // sans "::x" suffix
switch parts := strings.Split(fromFlag, "::"); len(parts) {
case 1:
main = parts[0]
case 2:
main = parts[0]
spec.searchFor = parts[1]
if parts[1] == "" {
// error
}
default:
return nil, fmt.Errorf("-from %q: invalid identifier specification (see -help for formats)", fromFlag)
}
if strings.HasSuffix(main, ".go") {
// main is "filename.go"
if spec.searchFor == "" {
return nil, fmt.Errorf("-from: filename %q must have a ::name suffix", main)
}
spec.filename = main
if !buildutil.FileExists(ctxt, spec.filename) {
return nil, fmt.Errorf("no such file: %s", spec.filename)
}
bp, err := buildutil.ContainingPackage(ctxt, wd, spec.filename)
if err != nil {
return nil, err
}
spec.pkg = bp.ImportPath
} else {
// main is one of:
// "importpath"
// "importpath".member
// (*"importpath".type).fieldormethod (parens and star optional)
if err := parseObjectSpec(&spec, main); err != nil {
return nil, err
}
}
if spec.searchFor != "" {
spec.fromName = spec.searchFor
}
// Sanitize the package.
// TODO(adonovan): test with relative packages. May need loader changes.
bp, err := ctxt.Import(spec.pkg, ".", build.FindOnly)
if err != nil {
return nil, fmt.Errorf("can't find package %q", spec.pkg)
}
spec.pkg = bp.ImportPath
if !isValidIdentifier(spec.fromName) {
return nil, fmt.Errorf("-from: invalid identifier %q", spec.fromName)
}
if Verbose {
fmt.Fprintf(os.Stderr, "-from spec: %+v\n", spec)
}
return &spec, nil
}