bee/code.go

262 lines
6.3 KiB
Go

// Copyright 2011 Gary Burd
// Copyright 2013 Unknown
//
// Licensed under the Apache License, Version 2.0 (the "License"): you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.
package main
import (
"go/ast"
"go/printer"
"go/scanner"
"go/token"
"math"
"strconv"
)
const (
notPredeclared = iota
predeclaredType
predeclaredConstant
predeclaredFunction
)
// predeclared represents the set of all predeclared identifiers.
var predeclared = map[string]int{
"bool": predeclaredType,
"byte": predeclaredType,
"complex128": predeclaredType,
"complex64": predeclaredType,
"error": predeclaredType,
"float32": predeclaredType,
"float64": predeclaredType,
"int16": predeclaredType,
"int32": predeclaredType,
"int64": predeclaredType,
"int8": predeclaredType,
"int": predeclaredType,
"rune": predeclaredType,
"string": predeclaredType,
"uint16": predeclaredType,
"uint32": predeclaredType,
"uint64": predeclaredType,
"uint8": predeclaredType,
"uint": predeclaredType,
"uintptr": predeclaredType,
"true": predeclaredConstant,
"false": predeclaredConstant,
"iota": predeclaredConstant,
"nil": predeclaredConstant,
"append": predeclaredFunction,
"cap": predeclaredFunction,
"close": predeclaredFunction,
"complex": predeclaredFunction,
"copy": predeclaredFunction,
"delete": predeclaredFunction,
"imag": predeclaredFunction,
"len": predeclaredFunction,
"make": predeclaredFunction,
"new": predeclaredFunction,
"panic": predeclaredFunction,
"print": predeclaredFunction,
"println": predeclaredFunction,
"real": predeclaredFunction,
"recover": predeclaredFunction,
}
const (
ExportLinkAnnotation AnnotationKind = iota
AnchorAnnotation
CommentAnnotation
PackageLinkAnnotation
BuiltinAnnotation
)
// annotationVisitor collects annotations.
type annotationVisitor struct {
annotations []Annotation
}
func (v *annotationVisitor) add(kind AnnotationKind, importPath string) {
v.annotations = append(v.annotations, Annotation{Kind: kind, ImportPath: importPath})
}
func (v *annotationVisitor) ignoreName() {
v.add(-1, "")
}
func (v *annotationVisitor) Visit(n ast.Node) ast.Visitor {
switch n := n.(type) {
case *ast.TypeSpec:
v.ignoreName()
ast.Walk(v, n.Type)
case *ast.FuncDecl:
if n.Recv != nil {
ast.Walk(v, n.Recv)
}
v.ignoreName()
ast.Walk(v, n.Type)
case *ast.Field:
for range n.Names {
v.ignoreName()
}
ast.Walk(v, n.Type)
case *ast.ValueSpec:
for range n.Names {
v.add(AnchorAnnotation, "")
}
if n.Type != nil {
ast.Walk(v, n.Type)
}
for _, x := range n.Values {
ast.Walk(v, x)
}
case *ast.Ident:
switch {
case n.Obj == nil && predeclared[n.Name] != notPredeclared:
v.add(BuiltinAnnotation, "")
case n.Obj != nil && ast.IsExported(n.Name):
v.add(ExportLinkAnnotation, "")
default:
v.ignoreName()
}
case *ast.SelectorExpr:
if x, _ := n.X.(*ast.Ident); x != nil {
if obj := x.Obj; obj != nil && obj.Kind == ast.Pkg {
if spec, _ := obj.Decl.(*ast.ImportSpec); spec != nil {
if path, err := strconv.Unquote(spec.Path.Value); err == nil {
v.add(PackageLinkAnnotation, path)
if path == "C" {
v.ignoreName()
} else {
v.add(ExportLinkAnnotation, path)
}
return nil
}
}
}
}
ast.Walk(v, n.X)
v.ignoreName()
default:
return v
}
return nil
}
func printDecl(decl ast.Node, fset *token.FileSet, buf []byte) (Code, []byte) {
v := &annotationVisitor{}
ast.Walk(v, decl)
buf = buf[:0]
err := (&printer.Config{Mode: printer.UseSpaces, Tabwidth: 4}).Fprint(sliceWriter{&buf}, fset, decl)
if err != nil {
return Code{Text: err.Error()}, buf
}
var annotations []Annotation
var s scanner.Scanner
fset = token.NewFileSet()
file := fset.AddFile("", fset.Base(), len(buf))
s.Init(file, buf, nil, scanner.ScanComments)
loop:
for {
pos, tok, lit := s.Scan()
switch tok {
case token.EOF:
break loop
case token.COMMENT:
p := file.Offset(pos)
e := p + len(lit)
if p > math.MaxInt16 || e > math.MaxInt16 {
break loop
}
annotations = append(annotations, Annotation{Kind: CommentAnnotation, Pos: int16(p), End: int16(e)})
case token.IDENT:
if len(v.annotations) == 0 {
// Oops!
break loop
}
annotation := v.annotations[0]
v.annotations = v.annotations[1:]
if annotation.Kind == -1 {
continue
}
p := file.Offset(pos)
e := p + len(lit)
if p > math.MaxInt16 || e > math.MaxInt16 {
break loop
}
annotation.Pos = int16(p)
annotation.End = int16(e)
if len(annotations) > 0 && annotation.Kind == ExportLinkAnnotation {
prev := annotations[len(annotations)-1]
if prev.Kind == PackageLinkAnnotation &&
prev.ImportPath == annotation.ImportPath &&
prev.End+1 == annotation.Pos {
// merge with previous
annotation.Pos = prev.Pos
annotations[len(annotations)-1] = annotation
continue loop
}
}
annotations = append(annotations, annotation)
}
}
return Code{Text: string(buf), Annotations: annotations}, buf
}
type AnnotationKind int16
type Annotation struct {
Pos, End int16
Kind AnnotationKind
ImportPath string
}
type Code struct {
Text string
Annotations []Annotation
}
func commentAnnotations(src string) []Annotation {
var annotations []Annotation
var s scanner.Scanner
fset := token.NewFileSet()
file := fset.AddFile("", fset.Base(), len(src))
s.Init(file, []byte(src), nil, scanner.ScanComments)
for {
pos, tok, lit := s.Scan()
switch tok {
case token.EOF:
return annotations
case token.COMMENT:
p := file.Offset(pos)
e := p + len(lit)
if p > math.MaxInt16 || e > math.MaxInt16 {
return annotations
}
annotations = append(annotations, Annotation{Kind: CommentAnnotation, Pos: int16(p), End: int16(e)})
}
}
}
type sliceWriter struct{ p *[]byte }
func (w sliceWriter) Write(p []byte) (int, error) {
*w.p = append(*w.p, p...)
return len(p), nil
}