func isEmpty(f *ast.File, g *ast.GenDecl) bool {
if g.Doc != nil || g.Specs != nil {
return false
}
for _, c := range f.Comments {
// if there is a comment in the declaration, it is not considered empty
if g.Pos() <= c.Pos() && c.End() <= g.End() {
return false
}
}
return true
}
// readType processes a type declaration.
//
func (r *reader) readType(decl *ast.GenDecl, spec *ast.TypeSpec) {
typ := r.lookupType(spec.Name.Name)
if typ == nil {
return // no name or blank name - ignore the type
}
// A type should be added at most once, so typ.decl
// should be nil - if it is not, simply overwrite it.
typ.decl = decl
// compute documentation
doc := spec.Doc
spec.Doc = nil // doc consumed - remove from AST
if doc == nil {
// no doc associated with the spec, use the declaration doc, if any
doc = decl.Doc
}
decl.Doc = nil // doc consumed - remove from AST
typ.doc = doc.Text()
// record anonymous fields (they may contribute methods)
// (some fields may have been recorded already when filtering
// exports, but that's ok)
var list []*ast.Field
list, typ.isStruct = fields(spec.Type)
for _, field := range list {
if len(field.Names) == 0 {
r.recordAnonymousField(typ, field.Type)
}
}
}
func (p *printer) genDecl(d *ast.GenDecl) {
p.setComment(d.Doc)
p.print(d.Pos(), d.Tok, blank)
if d.Lparen.IsValid() {
// group of parenthesized declarations
p.print(d.Lparen, token.LPAREN)
if n := len(d.Specs); n > 0 {
p.print(indent, formfeed)
if n > 1 && (d.Tok == token.CONST || d.Tok == token.VAR) {
// two or more grouped const/var declarations:
// determine if the type column must be kept
keepType := keepTypeColumn(d.Specs)
var line int
for i, s := range d.Specs {
if i > 0 {
p.linebreak(p.lineFor(s.Pos()), 1, ignore, p.linesFrom(line) > 0)
}
p.recordLine(&line)
p.valueSpec(s.(*ast.ValueSpec), keepType[i])
}
} else {
var line int
for i, s := range d.Specs {
if i > 0 {
p.linebreak(p.lineFor(s.Pos()), 1, ignore, p.linesFrom(line) > 0)
}
p.recordLine(&line)
p.spec(s, n, false)
}
}
p.print(unindent, formfeed)
}
p.print(d.Rparen, token.RPAREN)
} else {
// single declaration
p.spec(d.Specs[0], 1, true)
}
}
// 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, decl := range f.Decls {
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.
}
// 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:]...)
}
return true
}
// readValue processes a const or var declaration.
//
func (r *reader) readValue(decl *ast.GenDecl) {
// determine if decl should be associated with a type
// Heuristic: For each typed entry, determine the type name, if any.
// If there is exactly one type name that is sufficiently
// frequent, associate the decl with the respective type.
domName := ""
domFreq := 0
prev := ""
n := 0
for _, spec := range decl.Specs {
s, ok := spec.(*ast.ValueSpec)
if !ok {
continue // should not happen, but be conservative
}
name := ""
switch {
case s.Type != nil:
// a type is present; determine its name
if n, imp := baseTypeName(s.Type); !imp {
name = n
}
case decl.Tok == token.CONST:
// no type is present but we have a constant declaration;
// use the previous type name (w/o more type information
// we cannot handle the case of unnamed variables with
// initializer expressions except for some trivial cases)
name = prev
}
if name != "" {
// entry has a named type
if domName != "" && domName != name {
// more than one type name - do not associate
// with any type
domName = ""
break
}
domName = name
domFreq++
}
prev = name
n++
}
// nothing to do w/o a legal declaration
if n == 0 {
return
}
// determine values list with which to associate the Value for this decl
values := &r.values
const threshold = 0.75
if domName != "" && r.isVisible(domName) && domFreq >= int(float64(len(decl.Specs))*threshold) {
// typed entries are sufficiently frequent
if typ := r.lookupType(domName); typ != nil {
values = &typ.values // associate with that type
}
}
*values = append(*values, &Value{
Doc: decl.Doc.Text(),
Names: specNames(decl.Specs),
Decl: decl,
order: len(*values),
})
decl.Doc = nil // doc consumed - remove from AST
}