func gofmt(fset *token.FileSet, filename string, src *bytes.Buffer) error {
f, _, _, err := parse(fset, filename, src.Bytes(), false)
if err != nil {
return err
}
ast.SortImports(fset, f)
src.Reset()
return (&printer.Config{Mode: printerMode, Tabwidth: tabWidth}).Fprint(src, fset, f)
}
// Source formats src in canonical gofmt style and returns the result
// or an (I/O or syntax) error. src is expected to be a syntactically
// correct Go source file, or a list of Go declarations or statements.
//
// If src is a partial source file, the leading and trailing space of src
// is applied to the result (such that it has the same leading and trailing
// space as src), and the result is indented by the same amount as the first
// line of src containing code. Imports are not sorted for partial source files.
//
func Source(src []byte) ([]byte, error) {
fset := token.NewFileSet()
file, sourceAdj, indentAdj, err := parse(fset, "", src, true)
if err != nil {
return nil, err
}
if sourceAdj == nil {
// Complete source file.
// TODO(gri) consider doing this always.
ast.SortImports(fset, file)
}
return format(fset, file, sourceAdj, indentAdj, src, config)
}
// Node formats node in canonical gofmt style and writes the result to dst.
//
// The node type must be *ast.File, *printer.CommentedNode, []ast.Decl,
// []ast.Stmt, or assignment-compatible to ast.Expr, ast.Decl, ast.Spec,
// or ast.Stmt. Node does not modify node. Imports are not sorted for
// nodes representing partial source files (i.e., if the node is not an
// *ast.File or a *printer.CommentedNode not wrapping an *ast.File).
//
// The function may return early (before the entire result is written)
// and return a formatting error, for instance due to an incorrect AST.
//
func Node(dst io.Writer, fset *token.FileSet, node interface{}) error {
// Determine if we have a complete source file (file != nil).
var file *ast.File
var cnode *printer.CommentedNode
switch n := node.(type) {
case *ast.File:
file = n
case *printer.CommentedNode:
if f, ok := n.Node.(*ast.File); ok {
file = f
cnode = n
}
}
// Sort imports if necessary.
if file != nil && hasUnsortedImports(file) {
// Make a copy of the AST because ast.SortImports is destructive.
// TODO(gri) Do this more efficiently.
var buf bytes.Buffer
err := config.Fprint(&buf, fset, file)
if err != nil {
return err
}
file, err = parser.ParseFile(fset, "", buf.Bytes(), parserMode)
if err != nil {
// We should never get here. If we do, provide good diagnostic.
return fmt.Errorf("format.Node internal error (%s)", err)
}
ast.SortImports(fset, file)
// Use new file with sorted imports.
node = file
if cnode != nil {
node = &printer.CommentedNode{Node: file, Comments: cnode.Comments}
}
}
return config.Fprint(dst, fset, node)
}
// If in == nil, the source is the contents of the file with the given filename.
func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error {
if in == nil {
f, err := os.Open(filename)
if err != nil {
return err
}
defer f.Close()
in = f
}
src, err := ioutil.ReadAll(in)
if err != nil {
return err
}
file, sourceAdj, indentAdj, err := parse(fileSet, filename, src, stdin)
if err != nil {
return err
}
if rewrite != nil {
if sourceAdj == nil {
file = rewrite(file)
} else {
fmt.Fprintf(os.Stderr, "warning: rewrite ignored for incomplete programs\n")
}
}
ast.SortImports(fileSet, file)
if *simplifyAST {
simplify(file)
}
res, err := format(fileSet, file, sourceAdj, indentAdj, src, printer.Config{Mode: printerMode, Tabwidth: tabWidth})
if err != nil {
return err
}
if !bytes.Equal(src, res) {
// formatting has changed
if *list {
fmt.Fprintln(out, filename)
}
if *write {
err = ioutil.WriteFile(filename, res, 0644)
if err != nil {
return err
}
}
if *doDiff {
data, err := diff(src, res)
if err != nil {
return fmt.Errorf("computing diff: %s", err)
}
fmt.Printf("diff %s gofmt/%s\n", filename, filename)
out.Write(data)
}
}
if !*list && !*write && !*doDiff {
_, err = out.Write(res)
}
return err
}