// addImport adds the import path to the file f, if absent.
func addImport(f *ast.File, path string) {
if imports(f, path) {
return
}
newImport := &ast.ImportSpec{
Path: &ast.BasicLit{
Kind: token.STRING,
Value: strconv.Quote(path),
},
}
var impdecl *ast.GenDecl
// Find an import decl to add to.
for _, decl := range f.Decls {
gen, ok := decl.(*ast.GenDecl)
if ok && gen.Tok == token.IMPORT {
impdecl = gen
break
}
}
// No import decl found. Add one.
if impdecl == nil {
impdecl = &ast.GenDecl{
Tok: token.IMPORT,
}
f.Decls = append(f.Decls, nil)
copy(f.Decls[1:], f.Decls)
f.Decls[0] = impdecl
}
// Ensure the import decl has parentheses, if needed.
if len(impdecl.Specs) > 0 && !impdecl.Lparen.IsValid() {
impdecl.Lparen = impdecl.Pos()
}
// Assume the import paths are alphabetically ordered.
// If they are not, the result is ugly, but legal.
insertAt := len(impdecl.Specs) // default to end of specs
for i, spec := range impdecl.Specs {
impspec := spec.(*ast.ImportSpec)
if importPath(impspec) > path {
insertAt = i
break
}
}
impdecl.Specs = append(impdecl.Specs, nil)
copy(impdecl.Specs[insertAt+1:], impdecl.Specs[insertAt:])
impdecl.Specs[insertAt] = newImport
f.Imports = append(f.Imports, newImport)
}
// deleteImport deletes the import path from the file f, if present.
func deleteImport(f *ast.File, path string) (deleted bool) {
oldImport := importSpec(f, path)
// Find the import node that imports path, if any.
for i, decl := range f.Decls {
gen, ok := decl.(*ast.GenDecl)
if !ok || gen.Tok != token.IMPORT {
continue
}
for j, spec := range gen.Specs {
impspec := spec.(*ast.ImportSpec)
if oldImport != impspec {
continue
}
// We found an import spec that imports path.
// Delete it.
deleted = true
copy(gen.Specs[j:], gen.Specs[j+1:])
gen.Specs = gen.Specs[:len(gen.Specs)-1]
// If this was the last import spec in this decl,
// delete the decl, too.
if len(gen.Specs) == 0 {
copy(f.Decls[i:], f.Decls[i+1:])
f.Decls = f.Decls[:len(f.Decls)-1]
} else if len(gen.Specs) == 1 {
gen.Lparen = token.NoPos // drop parens
}
if j > 0 {
// We deleted an entry but now there will be
// a blank line-sized hole where the import was.
// Close the hole by making the previous
// import appear to "end" where this one did.
gen.Specs[j-1].(*ast.ImportSpec).EndPos = impspec.End()
}
break
}
}
// Delete it from f.Imports.
for i, imp := range f.Imports {
if imp == oldImport {
copy(f.Imports[i:], f.Imports[i+1:])
f.Imports = f.Imports[:len(f.Imports)-1]
break
}
}
return
}
func addImport(file *ast.File, pkg string) {
decl := &ast.GenDecl{
Tok: token.IMPORT,
}
file.Decls = append(file.Decls, nil)
copy(file.Decls[1:], file.Decls[:])
file.Decls[0] = decl
spec := &ast.ImportSpec{
Path: &ast.BasicLit{
Kind: token.STRING,
Value: pkg,
},
}
decl.Specs = append(decl.Specs, spec)
file.Imports = append(file.Imports, spec)
}
// deleteImport deletes the import path from the file f, if present.
func deleteImport(f *ast.File, path string) {
oldImport := importSpec(f, path)
// Find the import node that imports path, if any.
for i, decl := range f.Decls {
gen, ok := decl.(*ast.GenDecl)
if !ok || gen.Tok != token.IMPORT {
continue
}
for j, spec := range gen.Specs {
impspec := spec.(*ast.ImportSpec)
if oldImport != impspec {
continue
}
// We found an import spec that imports path.
// Delete it.
copy(gen.Specs[j:], gen.Specs[j+1:])
gen.Specs = gen.Specs[:len(gen.Specs)-1]
// If this was the last import spec in this decl,
// delete the decl, too.
if len(gen.Specs) == 0 {
copy(f.Decls[i:], f.Decls[i+1:])
f.Decls = f.Decls[:len(f.Decls)-1]
} else if len(gen.Specs) == 1 {
gen.Lparen = token.NoPos // drop parens
}
break
}
}
// Delete it from f.Imports.
for i, imp := range f.Imports {
if imp == oldImport {
copy(f.Imports[i:], f.Imports[i+1:])
f.Imports = f.Imports[:len(f.Imports)-1]
break
}
}
}
// AddNamedImport adds the import path to the file f, if absent.
// If name is not empty, it is used to rename the import.
//
// For example, calling
// AddNamedImport(fset, f, "pathpkg", "path")
// adds
// import pathpkg "path"
func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added bool) {
if imports(f, ipath) {
return false
}
newImport := &ast.ImportSpec{
Path: &ast.BasicLit{
Kind: token.STRING,
Value: strconv.Quote(ipath),
},
}
if name != "" {
newImport.Name = &ast.Ident{Name: name}
}
// Find an import decl to add to.
// The goal is to find an existing import
// whose import path has the longest shared
// prefix with ipath.
var (
bestMatch = -1 // length of longest shared prefix
lastImport = -1 // index in f.Decls of the file's final import decl
impDecl *ast.GenDecl // import decl containing the best match
impIndex = -1 // spec index in impDecl containing the best match
)
for i, decl := range f.Decls {
gen, ok := decl.(*ast.GenDecl)
if ok && gen.Tok == token.IMPORT {
lastImport = i
// Do not add to import "C", to avoid disrupting the
// association with its doc comment, breaking cgo.
if declImports(gen, "C") {
continue
}
// Match an empty import decl if that's all that is available.
if len(gen.Specs) == 0 && bestMatch == -1 {
impDecl = gen
}
// Compute longest shared prefix with imports in this group.
for j, spec := range gen.Specs {
impspec := spec.(*ast.ImportSpec)
n := matchLen(importPath(impspec), ipath)
if n > bestMatch {
bestMatch = n
impDecl = gen
impIndex = j
}
}
}
}
// If no import decl found, add one after the last import.
if impDecl == nil {
impDecl = &ast.GenDecl{
Tok: token.IMPORT,
}
if lastImport >= 0 {
impDecl.TokPos = f.Decls[lastImport].End()
} else {
// There are no existing imports.
// Our new import goes after the package declaration and after
// the comment, if any, that starts on the same line as the
// package declaration.
impDecl.TokPos = f.Package
file := fset.File(f.Package)
pkgLine := file.Line(f.Package)
for _, c := range f.Comments {
if file.Line(c.Pos()) > pkgLine {
break
}
impDecl.TokPos = c.End()
}
}
f.Decls = append(f.Decls, nil)
copy(f.Decls[lastImport+2:], f.Decls[lastImport+1:])
f.Decls[lastImport+1] = impDecl
}
// Insert new import at insertAt.
insertAt := 0
if impIndex >= 0 {
// insert after the found import
insertAt = impIndex + 1
}
impDecl.Specs = append(impDecl.Specs, nil)
copy(impDecl.Specs[insertAt+1:], impDecl.Specs[insertAt:])
impDecl.Specs[insertAt] = newImport
pos := impDecl.Pos()
if insertAt > 0 {
// If there is a comment after an existing import, preserve the comment
// position by adding the new import after the comment.
if spec, ok := impDecl.Specs[insertAt-1].(*ast.ImportSpec); ok && spec.Comment != nil {
pos = spec.Comment.End()
} else {
// Assign same position as the previous import,
// so that the sorter sees it as being in the same block.
pos = impDecl.Specs[insertAt-1].Pos()
}
}
if newImport.Name != nil {
newImport.Name.NamePos = pos
}
newImport.Path.ValuePos = pos
newImport.EndPos = pos
// Clean up parens. impDecl contains at least one spec.
if len(impDecl.Specs) == 1 {
// Remove unneeded parens.
impDecl.Lparen = token.NoPos
} else if !impDecl.Lparen.IsValid() {
// impDecl needs parens added.
impDecl.Lparen = impDecl.Specs[0].Pos()
}
f.Imports = append(f.Imports, newImport)
if len(f.Decls) <= 1 {
return true
}
// Merge all the import declarations into the first one.
var first *ast.GenDecl
for i := 0; i < len(f.Decls); i++ {
decl := f.Decls[i]
gen, ok := decl.(*ast.GenDecl)
if !ok || gen.Tok != token.IMPORT || declImports(gen, "C") {
continue
}
if first == nil {
first = gen
continue // Don't touch the first one.
}
// We now know there is more than one package in this import
// declaration. Ensure that it ends up parenthesized.
first.Lparen = first.Pos()
// Move the imports of the other import declaration to the first one.
for _, spec := range gen.Specs {
spec.(*ast.ImportSpec).Path.ValuePos = first.Pos()
first.Specs = append(first.Specs, spec)
}
f.Decls = append(f.Decls[:i], f.Decls[i+1:]...)
i--
}
return true
}
// DeleteNamedImport deletes the import with the given name and path from the file f, if present.
func DeleteNamedImport(fset *token.FileSet, f *ast.File, name, path string) (deleted bool) {
var delspecs []*ast.ImportSpec
var delcomments []*ast.CommentGroup
// Find the import nodes that import path, if any.
for i := 0; i < len(f.Decls); i++ {
decl := f.Decls[i]
gen, ok := decl.(*ast.GenDecl)
if !ok || gen.Tok != token.IMPORT {
continue
}
for j := 0; j < len(gen.Specs); j++ {
spec := gen.Specs[j]
impspec := spec.(*ast.ImportSpec)
if impspec.Name == nil && name != "" {
continue
}
if impspec.Name != nil && impspec.Name.Name != name {
continue
}
if importPath(impspec) != path {
continue
}
// We found an import spec that imports path.
// Delete it.
delspecs = append(delspecs, impspec)
deleted = true
copy(gen.Specs[j:], gen.Specs[j+1:])
gen.Specs = gen.Specs[:len(gen.Specs)-1]
// If this was the last import spec in this decl,
// delete the decl, too.
if len(gen.Specs) == 0 {
copy(f.Decls[i:], f.Decls[i+1:])
f.Decls = f.Decls[:len(f.Decls)-1]
i--
break
} else if len(gen.Specs) == 1 {
if impspec.Doc != nil {
delcomments = append(delcomments, impspec.Doc)
}
if impspec.Comment != nil {
delcomments = append(delcomments, impspec.Comment)
}
for _, cg := range f.Comments {
// Found comment on the same line as the import spec.
if cg.End() < impspec.Pos() && fset.Position(cg.End()).Line == fset.Position(impspec.Pos()).Line {
delcomments = append(delcomments, cg)
break
}
}
gen.Lparen = token.NoPos // drop parens
spec := gen.Specs[0].(*ast.ImportSpec)
if spec.Doc != nil {
// Move the documentation above the import statement.
gen.TokPos = spec.Doc.End() + 1
}
for _, cg := range f.Comments {
if cg.End() < spec.Pos() && fset.Position(cg.End()).Line == fset.Position(spec.Pos()).Line {
for fset.Position(gen.TokPos).Line != fset.Position(spec.Pos()).Line {
fset.File(gen.TokPos).MergeLine(fset.Position(gen.TokPos).Line)
}
break
}
}
}
if j > 0 {
lastImpspec := gen.Specs[j-1].(*ast.ImportSpec)
lastLine := fset.Position(lastImpspec.Path.ValuePos).Line
line := fset.Position(impspec.Path.ValuePos).Line
// We deleted an entry but now there may be
// a blank line-sized hole where the import was.
if line-lastLine > 1 {
// There was a blank line immediately preceding the deleted import,
// so there's no need to close the hole.
// Do nothing.
} else {
// There was no blank line. Close the hole.
fset.File(gen.Rparen).MergeLine(line)
}
}
j--
}
}
// Delete imports from f.Imports.
for i := 0; i < len(f.Imports); i++ {
imp := f.Imports[i]
for j, del := range delspecs {
if imp == del {
copy(f.Imports[i:], f.Imports[i+1:])
f.Imports = f.Imports[:len(f.Imports)-1]
copy(delspecs[j:], delspecs[j+1:])
delspecs = delspecs[:len(delspecs)-1]
i--
break
}
}
}
// Delete comments from f.Comments.
for i := 0; i < len(f.Comments); i++ {
cg := f.Comments[i]
for j, del := range delcomments {
if cg == del {
copy(f.Comments[i:], f.Comments[i+1:])
f.Comments = f.Comments[:len(f.Comments)-1]
copy(delcomments[j:], delcomments[j+1:])
delcomments = delcomments[:len(delcomments)-1]
i--
break
}
}
}
if len(delspecs) > 0 {
panic(fmt.Sprintf("deleted specs from Decls but not Imports: %v", delspecs))
}
return
}
// AddNamedImport adds the import path to the file f, if absent.
// If name is not empty, it is used to rename the import.
//
// For example, calling
// AddNamedImport(fset, f, "pathpkg", "path")
// adds
// import pathpkg "path"
func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added bool) {
if imports(f, ipath) {
return false
}
newImport := &ast.ImportSpec{
Path: &ast.BasicLit{
Kind: token.STRING,
Value: strconv.Quote(ipath),
},
}
if name != "" {
newImport.Name = &ast.Ident{Name: name}
}
// Find an import decl to add to.
var (
bestMatch = -1
lastImport = -1
impDecl *ast.GenDecl
impIndex = -1
hasImports = false
)
for i, decl := range f.Decls {
gen, ok := decl.(*ast.GenDecl)
if ok && gen.Tok == token.IMPORT {
hasImports = true
lastImport = i
// Do not add to import "C", to avoid disrupting the
// association with its doc comment, breaking cgo.
if declImports(gen, "C") {
continue
}
// Compute longest shared prefix with imports in this block.
for j, spec := range gen.Specs {
impspec := spec.(*ast.ImportSpec)
n := matchLen(importPath(impspec), ipath)
if n > bestMatch {
bestMatch = n
impDecl = gen
impIndex = j
}
}
}
}
// If no import decl found, add one after the last import.
if impDecl == nil {
// TODO(bradfitz): remove this hack. See comment below on
// addImportViaSourceModification.
if !hasImports {
f2, err := addImportViaSourceModification(fset, f, name, ipath)
if err == nil {
*f = *f2
return true
}
log.Printf("addImportViaSourceModification error: %v", err)
}
// TODO(bradfitz): fix above and resume using this old code:
impDecl = &ast.GenDecl{
Tok: token.IMPORT,
}
f.Decls = append(f.Decls, nil)
copy(f.Decls[lastImport+2:], f.Decls[lastImport+1:])
f.Decls[lastImport+1] = impDecl
}
// Ensure the import decl has parentheses, if needed.
if len(impDecl.Specs) > 0 && !impDecl.Lparen.IsValid() {
impDecl.Lparen = impDecl.Pos()
}
insertAt := impIndex + 1
if insertAt == 0 {
insertAt = len(impDecl.Specs)
}
impDecl.Specs = append(impDecl.Specs, nil)
copy(impDecl.Specs[insertAt+1:], impDecl.Specs[insertAt:])
impDecl.Specs[insertAt] = newImport
if insertAt > 0 {
// Assign same position as the previous import,
// so that the sorter sees it as being in the same block.
prev := impDecl.Specs[insertAt-1]
newImport.Path.ValuePos = prev.Pos()
newImport.EndPos = prev.Pos()
}
if len(impDecl.Specs) > 1 && impDecl.Lparen == 0 {
// set Lparen to something not zero, so the printer prints
// the full block rather just the first ImportSpec.
impDecl.Lparen = 1
}
f.Imports = append(f.Imports, newImport)
return true
}
// DeleteImport deletes the import path from the file f, if present.
func DeleteImport(fset *token.FileSet, f *ast.File, path string) (deleted bool) {
var delspecs []*ast.ImportSpec
// Find the import nodes that import path, if any.
for i := 0; i < len(f.Decls); i++ {
decl := f.Decls[i]
gen, ok := decl.(*ast.GenDecl)
if !ok || gen.Tok != token.IMPORT {
continue
}
for j := 0; j < len(gen.Specs); j++ {
spec := gen.Specs[j]
impspec := spec.(*ast.ImportSpec)
if importPath(impspec) != path {
continue
}
// We found an import spec that imports path.
// Delete it.
delspecs = append(delspecs, impspec)
deleted = true
copy(gen.Specs[j:], gen.Specs[j+1:])
gen.Specs = gen.Specs[:len(gen.Specs)-1]
// If this was the last import spec in this decl,
// delete the decl, too.
if len(gen.Specs) == 0 {
copy(f.Decls[i:], f.Decls[i+1:])
f.Decls = f.Decls[:len(f.Decls)-1]
i--
break
} else if len(gen.Specs) == 1 {
gen.Lparen = token.NoPos // drop parens
}
if j > 0 {
lastImpspec := gen.Specs[j-1].(*ast.ImportSpec)
lastLine := fset.Position(lastImpspec.Path.ValuePos).Line
line := fset.Position(impspec.Path.ValuePos).Line
// We deleted an entry but now there may be
// a blank line-sized hole where the import was.
if line-lastLine > 1 {
// There was a blank line immediately preceding the deleted import,
// so there's no need to close the hole.
// Do nothing.
} else {
// There was no blank line. Close the hole.
fset.File(gen.Rparen).MergeLine(line)
}
}
j--
}
}
// Delete them from f.Imports.
for i := 0; i < len(f.Imports); i++ {
imp := f.Imports[i]
for j, del := range delspecs {
if imp == del {
copy(f.Imports[i:], f.Imports[i+1:])
f.Imports = f.Imports[:len(f.Imports)-1]
copy(delspecs[j:], delspecs[j+1:])
delspecs = delspecs[:len(delspecs)-1]
i--
break
}
}
}
if len(delspecs) > 0 {
panic(fmt.Sprintf("deleted specs from Decls but not Imports: %v", delspecs))
}
return
}
// addImport adds the import path to the file f, if absent.
func addImport(f *ast.File, ipath string) (added bool) {
if imports(f, ipath) {
return false
}
// Determine name of import.
// Assume added imports follow convention of using last element.
_, name := path.Split(ipath)
// Rename any conflicting top-level references from name to name_.
renameTop(f, name, name+"_")
newImport := &ast.ImportSpec{
Path: &ast.BasicLit{
Kind: token.STRING,
Value: strconv.Quote(ipath),
},
}
// Find an import decl to add to.
var (
bestMatch = -1
lastImport = -1
impDecl *ast.GenDecl
impIndex = -1
)
for i, decl := range f.Decls {
gen, ok := decl.(*ast.GenDecl)
if ok && gen.Tok == token.IMPORT {
lastImport = i
// Do not add to import "C", to avoid disrupting the
// association with its doc comment, breaking cgo.
if declImports(gen, "C") {
continue
}
// Compute longest shared prefix with imports in this block.
for j, spec := range gen.Specs {
impspec := spec.(*ast.ImportSpec)
n := matchLen(importPath(impspec), ipath)
if n > bestMatch {
bestMatch = n
impDecl = gen
impIndex = j
}
}
}
}
// If no import decl found, add one after the last import.
if impDecl == nil {
impDecl = &ast.GenDecl{
Tok: token.IMPORT,
}
f.Decls = append(f.Decls, nil)
copy(f.Decls[lastImport+2:], f.Decls[lastImport+1:])
f.Decls[lastImport+1] = impDecl
}
// Ensure the import decl has parentheses, if needed.
if len(impDecl.Specs) > 0 && !impDecl.Lparen.IsValid() {
impDecl.Lparen = impDecl.Pos()
}
insertAt := impIndex + 1
if insertAt == 0 {
insertAt = len(impDecl.Specs)
}
impDecl.Specs = append(impDecl.Specs, nil)
copy(impDecl.Specs[insertAt+1:], impDecl.Specs[insertAt:])
impDecl.Specs[insertAt] = newImport
if insertAt > 0 {
// Assign same position as the previous import,
// so that the sorter sees it as being in the same block.
prev := impDecl.Specs[insertAt-1]
newImport.Path.ValuePos = prev.Pos()
newImport.EndPos = prev.Pos()
}
f.Imports = append(f.Imports, newImport)
return true
}
func fixImports(f *ast.File) {
declShort := map[string]*ast.ImportSpec{} // key: either base package "fmt", "http" or renamed package
usedShort := map[string]bool{} // Same key
var genDecls []*ast.GenDecl
addImport := func(ipath string) {
is := &ast.ImportSpec{
Path: &ast.BasicLit{
Kind: token.STRING,
Value: strconv.Quote(ipath),
},
}
declShort[path.Base(ipath)] = is
if len(genDecls) == 0 {
genDecls = append(genDecls, &ast.GenDecl{
Tok: token.IMPORT,
})
f.Decls = append([]ast.Decl{genDecls[0]}, f.Decls...)
f.Imports = append(f.Imports, is)
}
gd0 := genDecls[0]
// Prepend onto gd0.Specs:
// Make room for it (nil), slide everything down, then set [0].
gd0.Specs = append(gd0.Specs, nil)
copy(gd0.Specs[1:], gd0.Specs[:])
gd0.Specs[0] = is
if len(gd0.Specs) > 1 && gd0.Lparen == 0 {
gd0.Lparen = 1 // something not zero
}
}
var visitor visitFn
depth := 0
visitor = visitFn(func(node ast.Node) ast.Visitor {
if node == nil {
depth--
return visitor
}
depth++
switch v := node.(type) {
case *ast.GenDecl:
if v.Tok == token.IMPORT {
genDecls = append(genDecls, v)
}
case *ast.ImportSpec:
if v.Name != nil {
declShort[v.Name.Name] = v
} else {
local := path.Base(strings.Trim(v.Path.Value, `\"`))
declShort[local] = v
}
case *ast.SelectorExpr:
if xident, ok := v.X.(*ast.Ident); ok {
pkgName := xident.Name
usedShort[pkgName] = true
if declShort[pkgName] == nil {
key := pkgName + "." + v.Sel.Name
if fullImport, ok := common[key]; ok {
addImport(fullImport)
}
}
}
}
// fmt.Printf("%ssaw a %T\n", indent, node)
return visitor
})
ast.Walk(visitor, f)
// Nil out any unused ImportSpecs, to be removed in following passes
unusedImport := map[*ast.ImportSpec]bool{}
for pkg, is := range declShort {
if !usedShort[pkg] && pkg != "_" && pkg != "." {
unusedImport[is] = true
}
}
for _, gd := range genDecls {
gd.Specs = filterUnusedSpecs(unusedImport, gd.Specs)
if len(gd.Specs) == 1 {
gd.Lparen = 0
}
}
f.Decls = filterEmptyDecls(f.Decls)
f.Imports = filterUnusedImports(unusedImport, f.Imports)
}
// DeleteImport deletes the import path from the file f, if present.
func DeleteImport(fset *token.FileSet, f *ast.File, path string) (deleted bool) {
oldImport := importSpec(f, path)
// Find the import node that imports path, if any.
for i, decl := range f.Decls {
gen, ok := decl.(*ast.GenDecl)
if !ok || gen.Tok != token.IMPORT {
continue
}
for j, spec := range gen.Specs {
impspec := spec.(*ast.ImportSpec)
if oldImport != impspec {
continue
}
// We found an import spec that imports path.
// Delete it.
deleted = true
copy(gen.Specs[j:], gen.Specs[j+1:])
gen.Specs = gen.Specs[:len(gen.Specs)-1]
// If this was the last import spec in this decl,
// delete the decl, too.
if len(gen.Specs) == 0 {
copy(f.Decls[i:], f.Decls[i+1:])
f.Decls = f.Decls[:len(f.Decls)-1]
} else if len(gen.Specs) == 1 {
gen.Lparen = token.NoPos // drop parens
}
if j > 0 {
lastImpspec := gen.Specs[j-1].(*ast.ImportSpec)
lastLine := fset.Position(lastImpspec.Path.ValuePos).Line
line := fset.Position(impspec.Path.ValuePos).Line
// We deleted an entry but now there may be
// a blank line-sized hole where the import was.
if line-lastLine > 1 {
// There was a blank line immediately preceeing the deleted import,
// so there's no need to close the hole.
// Do nothing.
} else {
// There was no blank line.
// Close the hole by making the previous
// import appear to "end" where this one did.
lastImpspec.EndPos = impspec.End()
}
}
break
}
}
// Delete it from f.Imports.
for i, imp := range f.Imports {
if imp == oldImport {
copy(f.Imports[i:], f.Imports[i+1:])
f.Imports = f.Imports[:len(f.Imports)-1]
break
}
}
return
}