// fastQueryPos parses the position string and returns a queryPos.
// It parses only a single file and does not run the type checker.
func fastQueryPos(ctxt *build.Context, pos string) (*queryPos, error) {
filename, startOffset, endOffset, err := parsePos(pos)
if err != nil {
return nil, err
}
// Parse the file, opening it the file via the build.Context
// so that we observe the effects of the -modified flag.
fset := token.NewFileSet()
cwd, _ := os.Getwd()
f, err := buildutil.ParseFile(fset, ctxt, nil, cwd, filename, parser.Mode(0))
// ParseFile usually returns a partial file along with an error.
// Only fail if there is no file.
if f == nil {
return nil, err
}
if !f.Pos().IsValid() {
return nil, fmt.Errorf("%s is not a Go source file", filename)
}
start, end, err := fileOffsetToPos(fset.File(f.Pos()), startOffset, endOffset)
if err != nil {
return nil, err
}
path, exact := astutil.PathEnclosingInterval(f, start, end)
if path == nil {
return nil, fmt.Errorf("no syntax here")
}
return &queryPos{fset, start, end, path, exact, nil}, nil
}
// findPackageMember returns the type and position of the declaration of
// pkg.member by loading and parsing the files of that package.
// srcdir is the directory in which the import appears.
func findPackageMember(ctxt *build.Context, fset *token.FileSet, srcdir, pkg, member string) (token.Token, token.Pos, error) {
bp, err := ctxt.Import(pkg, srcdir, 0)
if err != nil {
return 0, token.NoPos, err // no files for package
}
// TODO(adonovan): opt: parallelize.
for _, fname := range bp.GoFiles {
filename := filepath.Join(bp.Dir, fname)
// Parse the file, opening it the file via the build.Context
// so that we observe the effects of the -modified flag.
f, _ := buildutil.ParseFile(fset, ctxt, nil, ".", filename, parser.Mode(0))
if f == nil {
continue
}
// Find a package-level decl called 'member'.
for _, decl := range f.Decls {
switch decl := decl.(type) {
case *ast.GenDecl:
for _, spec := range decl.Specs {
switch spec := spec.(type) {
case *ast.ValueSpec:
// const or var
for _, id := range spec.Names {
if id.Name == member {
return decl.Tok, id.Pos(), nil
}
}
case *ast.TypeSpec:
if spec.Name.Name == member {
return token.TYPE, spec.Name.Pos(), nil
}
case *ast.AliasSpec:
if spec.Name.Name == member {
return decl.Tok, spec.Name.Pos(), nil
}
}
}
case *ast.FuncDecl:
if decl.Recv == nil && decl.Name.Name == member {
return token.FUNC, decl.Name.Pos(), nil
}
}
}
}
return 0, token.NoPos, fmt.Errorf("couldn't find declaration of %s in %q", member, pkg)
}
// 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
}