Beispiel #1
0
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
}
Beispiel #2
0
// 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)
		}
	}
}
Beispiel #3
0
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)
	}
}
Beispiel #4
0
// 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
}
Beispiel #5
0
// 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
}