--- /dev/null
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate go run mkstdlib.go
+
+// Package imports implements a Go pretty-printer (like package "go/format")
+// that also adds or removes import statements as necessary.
+package imports
+
+import (
+ "bufio"
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/format"
+ "go/parser"
+ "go/printer"
+ "go/token"
+ "io"
+ "regexp"
+ "strconv"
+ "strings"
+
+ "golang.org/x/tools/go/ast/astutil"
+)
+
+// Options is golang.org/x/tools/imports.Options with extra internal-only options.
+type Options struct {
+ Env *ProcessEnv // The environment to use. Note: this contains the cached module and filesystem state.
+
+ // LocalPrefix is a comma-separated string of import path prefixes, which, if
+ // set, instructs Process to sort the import paths with the given prefixes
+ // into another group after 3rd-party packages.
+ LocalPrefix string
+
+ Fragment bool // Accept fragment of a source file (no package statement)
+ AllErrors bool // Report all errors (not just the first 10 on different lines)
+
+ Comments bool // Print comments (true if nil *Options provided)
+ TabIndent bool // Use tabs for indent (true if nil *Options provided)
+ TabWidth int // Tab width (8 if nil *Options provided)
+
+ FormatOnly bool // Disable the insertion and deletion of imports
+}
+
+// Process implements golang.org/x/tools/imports.Process with explicit context in opt.Env.
+func Process(filename string, src []byte, opt *Options) (formatted []byte, err error) {
+ fileSet := token.NewFileSet()
+ file, adjust, err := parse(fileSet, filename, src, opt)
+ if err != nil {
+ return nil, err
+ }
+
+ if !opt.FormatOnly {
+ if err := fixImports(fileSet, file, filename, opt.Env); err != nil {
+ return nil, err
+ }
+ }
+ return formatFile(fileSet, file, src, adjust, opt)
+}
+
+// FixImports returns a list of fixes to the imports that, when applied,
+// will leave the imports in the same state as Process. src and opt must
+// be specified.
+//
+// Note that filename's directory influences which imports can be chosen,
+// so it is important that filename be accurate.
+func FixImports(filename string, src []byte, opt *Options) (fixes []*ImportFix, err error) {
+ fileSet := token.NewFileSet()
+ file, _, err := parse(fileSet, filename, src, opt)
+ if err != nil {
+ return nil, err
+ }
+
+ return getFixes(fileSet, file, filename, opt.Env)
+}
+
+// ApplyFixes applies all of the fixes to the file and formats it. extraMode
+// is added in when parsing the file. src and opts must be specified, but no
+// env is needed.
+func ApplyFixes(fixes []*ImportFix, filename string, src []byte, opt *Options, extraMode parser.Mode) (formatted []byte, err error) {
+ // Don't use parse() -- we don't care about fragments or statement lists
+ // here, and we need to work with unparseable files.
+ fileSet := token.NewFileSet()
+ parserMode := parser.Mode(0)
+ if opt.Comments {
+ parserMode |= parser.ParseComments
+ }
+ if opt.AllErrors {
+ parserMode |= parser.AllErrors
+ }
+ parserMode |= extraMode
+
+ file, err := parser.ParseFile(fileSet, filename, src, parserMode)
+ if file == nil {
+ return nil, err
+ }
+
+ // Apply the fixes to the file.
+ apply(fileSet, file, fixes)
+
+ return formatFile(fileSet, file, src, nil, opt)
+}
+
+func formatFile(fileSet *token.FileSet, file *ast.File, src []byte, adjust func(orig []byte, src []byte) []byte, opt *Options) ([]byte, error) {
+ mergeImports(fileSet, file)
+ sortImports(opt.LocalPrefix, fileSet, file)
+ imps := astutil.Imports(fileSet, file)
+ var spacesBefore []string // import paths we need spaces before
+ for _, impSection := range imps {
+ // Within each block of contiguous imports, see if any
+ // import lines are in different group numbers. If so,
+ // we'll need to put a space between them so it's
+ // compatible with gofmt.
+ lastGroup := -1
+ for _, importSpec := range impSection {
+ importPath, _ := strconv.Unquote(importSpec.Path.Value)
+ groupNum := importGroup(opt.LocalPrefix, importPath)
+ if groupNum != lastGroup && lastGroup != -1 {
+ spacesBefore = append(spacesBefore, importPath)
+ }
+ lastGroup = groupNum
+ }
+
+ }
+
+ printerMode := printer.UseSpaces
+ if opt.TabIndent {
+ printerMode |= printer.TabIndent
+ }
+ printConfig := &printer.Config{Mode: printerMode, Tabwidth: opt.TabWidth}
+
+ var buf bytes.Buffer
+ err := printConfig.Fprint(&buf, fileSet, file)
+ if err != nil {
+ return nil, err
+ }
+ out := buf.Bytes()
+ if adjust != nil {
+ out = adjust(src, out)
+ }
+ if len(spacesBefore) > 0 {
+ out, err = addImportSpaces(bytes.NewReader(out), spacesBefore)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ out, err = format.Source(out)
+ if err != nil {
+ return nil, err
+ }
+ return out, nil
+}
+
+// parse parses src, which was read from filename,
+// as a Go source file or statement list.
+func parse(fset *token.FileSet, filename string, src []byte, opt *Options) (*ast.File, func(orig, src []byte) []byte, error) {
+ parserMode := parser.Mode(0)
+ if opt.Comments {
+ parserMode |= parser.ParseComments
+ }
+ if opt.AllErrors {
+ parserMode |= parser.AllErrors
+ }
+
+ // Try as whole source file.
+ file, err := parser.ParseFile(fset, filename, src, parserMode)
+ if err == nil {
+ return file, nil, nil
+ }
+ // If the error is that the source file didn't begin with a
+ // package line and we accept fragmented input, fall through to
+ // try as a source fragment. Stop and return on any other error.
+ if !opt.Fragment || !strings.Contains(err.Error(), "expected 'package'") {
+ return nil, nil, err
+ }
+
+ // If this is a declaration list, make it a source file
+ // by inserting a package clause.
+ // Insert using a ;, not a newline, so that parse errors are on
+ // the correct line.
+ const prefix = "package main;"
+ psrc := append([]byte(prefix), src...)
+ file, err = parser.ParseFile(fset, filename, psrc, parserMode)
+ if err == nil {
+ // Gofmt will turn the ; into a \n.
+ // Do that ourselves now and update the file contents,
+ // so that positions and line numbers are correct going forward.
+ psrc[len(prefix)-1] = '\n'
+ fset.File(file.Package).SetLinesForContent(psrc)
+
+ // If a main function exists, we will assume this is a main
+ // package and leave the file.
+ if containsMainFunc(file) {
+ return file, nil, nil
+ }
+
+ adjust := func(orig, src []byte) []byte {
+ // Remove the package clause.
+ src = src[len(prefix):]
+ return matchSpace(orig, src)
+ }
+ return file, adjust, nil
+ }
+ // If the error is that the source file didn't begin with a
+ // declaration, fall through to try as a statement list.
+ // Stop and return on any other error.
+ if !strings.Contains(err.Error(), "expected declaration") {
+ return nil, nil, err
+ }
+
+ // If this is a statement list, make it a source file
+ // by inserting a package clause and turning the list
+ // into a function body. This handles expressions too.
+ // Insert using a ;, not a newline, so that the line numbers
+ // in fsrc match the ones in src.
+ fsrc := append(append([]byte("package p; func _() {"), src...), '}')
+ file, err = parser.ParseFile(fset, filename, fsrc, parserMode)
+ if err == nil {
+ adjust := func(orig, src []byte) []byte {
+ // Remove the wrapping.
+ // Gofmt has turned the ; into a \n\n.
+ src = src[len("package p\n\nfunc _() {"):]
+ src = src[:len(src)-len("}\n")]
+ // Gofmt has also indented the function body one level.
+ // Remove that indent.
+ src = bytes.Replace(src, []byte("\n\t"), []byte("\n"), -1)
+ return matchSpace(orig, src)
+ }
+ return file, adjust, nil
+ }
+
+ // Failed, and out of options.
+ return nil, nil, err
+}
+
+// containsMainFunc checks if a file contains a function declaration with the
+// function signature 'func main()'
+func containsMainFunc(file *ast.File) bool {
+ for _, decl := range file.Decls {
+ if f, ok := decl.(*ast.FuncDecl); ok {
+ if f.Name.Name != "main" {
+ continue
+ }
+
+ if len(f.Type.Params.List) != 0 {
+ continue
+ }
+
+ if f.Type.Results != nil && len(f.Type.Results.List) != 0 {
+ continue
+ }
+
+ return true
+ }
+ }
+
+ return false
+}
+
+func cutSpace(b []byte) (before, middle, after []byte) {
+ i := 0
+ for i < len(b) && (b[i] == ' ' || b[i] == '\t' || b[i] == '\n') {
+ i++
+ }
+ j := len(b)
+ for j > 0 && (b[j-1] == ' ' || b[j-1] == '\t' || b[j-1] == '\n') {
+ j--
+ }
+ if i <= j {
+ return b[:i], b[i:j], b[j:]
+ }
+ return nil, nil, b[j:]
+}
+
+// matchSpace reformats src to use the same space context as orig.
+// 1) If orig begins with blank lines, matchSpace inserts them at the beginning of src.
+// 2) matchSpace copies the indentation of the first non-blank line in orig
+// to every non-blank line in src.
+// 3) matchSpace copies the trailing space from orig and uses it in place
+// of src's trailing space.
+func matchSpace(orig []byte, src []byte) []byte {
+ before, _, after := cutSpace(orig)
+ i := bytes.LastIndex(before, []byte{'\n'})
+ before, indent := before[:i+1], before[i+1:]
+
+ _, src, _ = cutSpace(src)
+
+ var b bytes.Buffer
+ b.Write(before)
+ for len(src) > 0 {
+ line := src
+ if i := bytes.IndexByte(line, '\n'); i >= 0 {
+ line, src = line[:i+1], line[i+1:]
+ } else {
+ src = nil
+ }
+ if len(line) > 0 && line[0] != '\n' { // not blank
+ b.Write(indent)
+ }
+ b.Write(line)
+ }
+ b.Write(after)
+ return b.Bytes()
+}
+
+var impLine = regexp.MustCompile(`^\s+(?:[\w\.]+\s+)?"(.+)"`)
+
+func addImportSpaces(r io.Reader, breaks []string) ([]byte, error) {
+ var out bytes.Buffer
+ in := bufio.NewReader(r)
+ inImports := false
+ done := false
+ for {
+ s, err := in.ReadString('\n')
+ if err == io.EOF {
+ break
+ } else if err != nil {
+ return nil, err
+ }
+
+ if !inImports && !done && strings.HasPrefix(s, "import") {
+ inImports = true
+ }
+ if inImports && (strings.HasPrefix(s, "var") ||
+ strings.HasPrefix(s, "func") ||
+ strings.HasPrefix(s, "const") ||
+ strings.HasPrefix(s, "type")) {
+ done = true
+ inImports = false
+ }
+ if inImports && len(breaks) > 0 {
+ if m := impLine.FindStringSubmatch(s); m != nil {
+ if m[1] == breaks[0] {
+ out.WriteByte('\n')
+ breaks = breaks[1:]
+ }
+ }
+ }
+
+ fmt.Fprint(&out, s)
+ }
+ return out.Bytes(), nil
+}
projects / dotfiles / .git / blobdiff