Golang ast.File类代码示例

func (p *printer) file(src *ast.File) {
	p.setComment(src.Doc)
	p.print(src.Pos(), token.PACKAGE, blank)
	p.expr(src.Name)

	if len(src.Decls) > 0 {
		tok := token.ILLEGAL
		for _, d := range src.Decls {
			prev := tok
			tok = declToken(d)
			// if the declaration token changed (e.g., from CONST to TYPE)
			// or the next declaration has documentation associated with it,
			// print an empty line between top-level declarations
			// (because p.linebreak is called with the position of d, which
			// is past any documentation, the minimum requirement is satisfied
			// even w/o the extra getDoc(d) nil-check - leave it in case the
			// linebreak logic improves - there's already a TODO).
			min := 1
			if prev != tok || getDoc(d) != nil {
				min = 2
			}
			p.linebreak(p.lineFor(d.Pos()), min, ignore, false)
			p.decl(d)
		}
	}

	p.print(newline)
}

func (p *printer) file(src *ast.File) {
	p.setComment(src.Doc)
	p.print(src.Pos(), token.PACKAGE, blank)
	p.expr(src.Name)
	p.declList(src.Decls)
	p.print(newline)
}

func generateGodebugIdentifiers(f *ast.File) {
	// Variables that won't have suffixes.
	idents.ctx = createConflictFreeName("ctx", f, false)
	idents.ok = createConflictFreeName("ok", f, false)
	idents.scope = createConflictFreeName("scope", f, false)
	idents.receiver = createConflictFreeName("receiver", f, false)
	idents.recoverChan = createConflictFreeName("rr", f, false)
	idents.recoverChanChan = createConflictFreeName("r", f, false)
	idents.recovers = createConflictFreeName("recovers", f, false)
	idents.panicVal = createConflictFreeName("v", f, false)
	idents.panicChan = createConflictFreeName("panicChan", f, false)

	idents.godebug = generateGodebugPkgName(f)

	// Variables that will have suffixes.
	idents.result = createConflictFreeName("result", f, true)
	idents.input = createConflictFreeName("input", f, true)

	// Variables with names derived from the filename.
	base := strings.Map(func(r rune) rune {
		if !unicode.In(r, unicode.Digit, unicode.Letter) {
			return '_'
		}
		return r
	}, filepath.Base(fs.Position(f.Pos()).Filename))
	if !unicode.IsLetter(rune(base[0])) {
		// identifiers must start with letters
		base = "a" + base
	}
	idents.fileScope = createConflictFreeName(base+"_scope", f, false)
	idents.fileContents = createConflictFreeName(base+"_contents", f, false)
}

// addFile adds the AST for a source file to the docReader.
// Adding the same AST multiple times is a no-op.
//
func (doc *docReader) addFile(src *ast.File) {
	// add package documentation
	if src.Doc != nil {
		// TODO(gri) This won't do the right thing if there is more
		//           than one file with package comments. Consider
		//           using ast.MergePackageFiles which handles these
		//           comments correctly (but currently looses BUG(...)
		//           comments).
		doc.doc = src.Doc
		src.Doc = nil // doc consumed - remove from ast.File node
	}

	// add all declarations
	for _, decl := range src.Decls {
		doc.addDecl(decl)
	}

	// collect BUG(...) comments
	for c := src.Comments; c != nil; c = c.Next {
		text := c.List[0].Text
		cstr := string(text)
		if m := bug_markers.ExecuteString(cstr); len(m) > 0 {
			// found a BUG comment; maybe empty
			if bstr := cstr[m[1]:]; bug_content.MatchString(bstr) {
				// non-empty BUG comment; collect comment without BUG prefix
				list := copyCommentList(c.List)
				list[0].Text = text[m[1]:]
				doc.bugs.Push(&ast.CommentGroup{list, nil})
			}
		}
	}
	src.Comments = nil // consumed unassociated comments - remove from ast.File node
}

// addFile adds the AST for a source file to the docReader.
// Adding the same AST multiple times is a no-op.
//
func (doc *docReader) addFile(src *ast.File) {
	// add package documentation
	if src.Doc != nil {
		doc.addDoc(src.Doc)
		src.Doc = nil // doc consumed - remove from ast.File node
	}

	// add all declarations
	for _, decl := range src.Decls {
		doc.addDecl(decl)
	}

	// collect BUG(...) comments
	for _, c := range src.Comments {
		text := c.List[0].Text
		if m := bug_markers.FindStringIndex(text); m != nil {
			// found a BUG comment; maybe empty
			if btxt := text[m[1]:]; bug_content.MatchString(btxt) {
				// non-empty BUG comment; collect comment without BUG prefix
				list := copyCommentList(c.List)
				list[0].Text = text[m[1]:]
				doc.bugs = append(doc.bugs, &ast.CommentGroup{list})
			}
		}
	}
	src.Comments = nil // consumed unassociated comments - remove from ast.File node
}

func insertIntVar(file *ast.File, name string, value int) {
	var before, after []ast.Decl

	if len(file.Decls) > 0 {
		hasImport := false
		if genDecl, ok := file.Decls[0].(*ast.GenDecl); ok {
			hasImport = genDecl.Tok == token.IMPORT
		}

		if hasImport {
			before, after = []ast.Decl{file.Decls[0]}, file.Decls[1:]
		} else {
			after = file.Decls
		}
	}

	file.Decls = append(before,
		&ast.GenDecl{
			Tok: token.VAR,
			Specs: []ast.Spec{
				&ast.ValueSpec{
					Names: []*ast.Ident{ast.NewIdent(name)},
					Type:  ast.NewIdent("int"),
					Values: []ast.Expr{
						&ast.BasicLit{
							Kind:  token.INT,
							Value: fmt.Sprintf("%d", value),
						},
					},
				},
			},
		},
	)
	file.Decls = append(file.Decls, after...)
}

func offsetLine(fset *token.FileSet, af *ast.File, offset int) (line int) {
	defer func() {
		if err := recover(); err != nil {
			line = 0
		}
	}()
	return fset.File(af.Pos()).Position(token.Pos(offset)).Line
}

func parseFileset(wks filesystem.WorkspaceFS, f *ast.File, fs *token.FileSet) []TokenPosition {
	var res []TokenPosition

	if f.Name != nil {
		res = appendTokenPosition(wks, res, fs.Position(f.Pos()), f.Name.Name, "", PACKAGE)
	}
	for _, i := range f.Imports {
		if i.Path != nil {
			res = appendTokenPosition(wks, res, fs.Position(f.Pos()), i.Path.Value, "", IMPORT)
		}
	}
	for _, d := range f.Decls {
		switch x := d.(type) {
		case *ast.FuncDecl:
			pos := fs.Position(x.Pos())
			if x.Recv != nil && len(x.Recv.List) > 0 {
				var recv *string
				n := x.Recv.List[0].Type
				id, ok := n.(*ast.Ident)
				if !ok {
					sid, ok := n.(*ast.StarExpr)
					if ok {
						id, ok = sid.X.(*ast.Ident)
						if ok {
							r := fmt.Sprintf("*%s", id.Name)
							recv = &r
						}
					}
				} else {
					recv = &id.Name
				}
				res = appendTokenPosition(wks, res, pos, x.Name.Name, *recv, METH)
			} else {
				res = appendTokenPosition(wks, res, pos, x.Name.Name, "", FUNC)
			}

		case *ast.GenDecl:
			switch x.Tok {
			case token.CONST:
				for _, s := range x.Specs {
					vs := s.(*ast.ValueSpec)
					res = appendTokenPosition(wks, res, fs.Position(vs.Pos()), vs.Names[0].Name, "", CONST)
				}
			case token.VAR:
				for _, s := range x.Specs {
					vs := s.(*ast.ValueSpec)
					res = appendTokenPosition(wks, res, fs.Position(vs.Pos()), vs.Names[0].Name, "", VAR)
				}
			case token.TYPE:
				for _, s := range x.Specs {
					vs := s.(*ast.TypeSpec)
					res = appendTokenPosition(wks, res, fs.Position(vs.Pos()), vs.Name.Name, "", TYPE)
				}
			}
		}
	}
	return res
}

func (scp *schemaParser) packageForFile(gofile *ast.File) (*loader.PackageInfo, error) {
	for pkg, pkgInfo := range scp.program.AllPackages {
		if pkg.Name() == gofile.Name.Name {
			return pkgInfo, nil
		}
	}
	fn := scp.program.Fset.File(gofile.Pos()).Name()
	return nil, fmt.Errorf("unable to determine package for %s", fn)
}

// 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)
}

func mergeASTFile(dst, src *ast.File) *ast.File {
	if dst == nil {
		return src
	}
	if dst.Doc != nil {
		dst.Doc = src.Doc
	}
	dst.Decls = append(dst.Decls, src.Decls...)
	return dst
}

// Inline replaces each instance of identifier k with v.Ident in ast.File f,
// for k, v := range m.
// For all inlines that were triggeres it also adds imports from v.Imports to f.
// In addition, it removes top level type declarations of the form
// type k ...
// for all k in m.
//
// Every k in m should be a valid identifier.
// Every v.Ident should be a valid expression.
func Inline(fset *token.FileSet, f *ast.File, m map[string]Target) error {
	// Build the inline map.
	im := map[string]reflect.Value{}
	for k, v := range m {
		expr, err := parser.ParseExpr(k)
		if err != nil {
			return fmt.Errorf("failed to parse `%s`: %s", k, err)
		}
		if _, ok := expr.(*ast.Ident); !ok {
			return fmt.Errorf("expected identifier, got %s which is %T", k, expr)
		}
		expr, err = parser.ParseExpr(v.Ident)
		if err != nil {
			return fmt.Errorf("failed to parse `%s`: %s", v.Ident, err)
		}
		s := v.Ident
		if _, ok := expr.(*ast.StarExpr); ok {
			s = fmt.Sprintf("(%s)", s)
		}
		im[k] = reflect.ValueOf(ast.Ident{Name: s})
	}
	// Filter `type XXX ...` declarations out if we are inlining XXX.
	cmap := ast.NewCommentMap(fset, f, f.Comments)
	to := 0
	for _, d := range f.Decls {
		skip := false
		if t, ok := d.(*ast.GenDecl); ok {
			for _, s := range t.Specs {
				ts, ok := s.(*ast.TypeSpec)
				if !ok {
					continue
				}
				if _, ok = im[ts.Name.String()]; ok {
					skip = true
				}
			}
		}
		if !skip {
			f.Decls[to] = d
			to++
		}
	}
	if to != len(f.Decls) {
		f.Decls = f.Decls[:to]
		// Remove comments for the declarations that were filtered out.
		f.Comments = cmap.Filter(f).Comments()
	}
	// Add imports for the inlines that were triggered.
	for k := range inline(im, f) {
		for _, imp := range m[k].Imports {
			astutil.AddImport(fset, f, imp)
		}
	}
	return nil
}

func extractMultipleStatementsAsFunc(
	astFile *ast.File,
	fileSet *token.FileSet,
	stmtsToExtract []ast.Node,
	parentNode ast.Node,
	extractedFuncName string) {
	params := varIdentsUsedIn(stmtsToExtract)
	varsDeclaredWithinStmtsToExtract := varIdentsDeclaredWithin(stmtsToExtract)
	util.MapStringAstIdentRemoveKeys(params, namesOf(varsDeclaredWithinStmtsToExtract))
	util.MapStringAstIdentRemoveKeys(params, namesOf(globalVarIdents(astFile)))

	allStmts := stmtsFromBlockStmt(parentNode)
	indexOfExtractedStmt := indexOf(stmtsToExtract[0].(ast.Stmt), *allStmts)
	varsUsedAfterwards := overlappingVarsIdentsUsedIn((*allStmts)[indexOfExtractedStmt+len(stmtsToExtract):], varsDeclaredWithinStmtsToExtract)

	newStmt := funcCallStmt(varsUsedAfterwards, extractedFuncName, params, (*allStmts)[indexOfExtractedStmt].Pos())
	replaceStmtsWithFuncCallStmt(newStmt,
		allStmts,
		indexOfExtractedStmt, len(stmtsToExtract))

	areaRemoved := areaRemoved(fileSet, (stmtsToExtract)[0].Pos(), (stmtsToExtract)[len(stmtsToExtract)-1].End())
	lineLengths := lineLengthsFrom(fileSet)
	lineNum, numLinesToCut, newLineLength := replacementModifications(fileSet, (stmtsToExtract)[0].Pos(), (stmtsToExtract)[len(stmtsToExtract)-1].End(), newStmt.End(), lineLengths, areaRemoved)

	shiftPosesAfterPos(astFile, newStmt, (stmtsToExtract)[len(stmtsToExtract)-1].End(), newStmt.End()-stmtsToExtract[len(stmtsToExtract)-1].End())

	multipleStmtFuncDecl := CopyNode(multipleStmtFuncDeclWith(
		extractedFuncName,
		fieldsFrom(params),
		stmtsFromNodes(stmtsToExtract),
		exprsFrom(varsUsedAfterwards),
	)).(*ast.FuncDecl)
	var moveOffset token.Pos
	RecalcPoses(multipleStmtFuncDecl, astFile.End()+2, &moveOffset, 0)
	astFile.Decls = append(astFile.Decls, multipleStmtFuncDecl)

	areaToBeAppended := insertionModificationsForStmts(astFile, multipleStmtFuncDecl, areaRemoved, exprsFrom(varsUsedAfterwards))

	lineLengths = append(
		lineLengths[:lineNum+1],
		lineLengths[lineNum+1+numLinesToCut:]...)
	lineLengths[lineNum] = newLineLength
	lineLengths = append(lineLengths, areaToBeAppended...)

	newFileSet := token.NewFileSet()
	newFileSet.AddFile(fileSet.File(1).Name(), 1, int(astFile.End()))
	newFileSet.File(1).SetLines(ConvertLineLengthsToLineOffsets(lineLengths))
	*fileSet = *newFileSet

	moveComments(astFile, moveOffset /*, needs a range to restict which comments to move*/)

}

// 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 removeImport(file *ast.File, ipath string) {
	var j int
	for j < len(file.Decls) {
		gen, ok := file.Decls[j].(*ast.GenDecl)
		if !ok || gen.Tok != token.IMPORT {
			j++
			continue
		}
		var i int
		for i < len(gen.Specs) {
			impspec := gen.Specs[i].(*ast.ImportSpec)
			if importPath(impspec) != ipath {
				i++
				continue
			}
			// If we found a match, pop the spec from gen.Specs
			gen.Specs[i] = gen.Specs[len(gen.Specs)-1]
			gen.Specs = gen.Specs[:len(gen.Specs)-1]
		}
		if len(gen.Specs) > 0 {
			j++
			continue
		}
		// Remove entire import decl if no imports left in it
		file.Decls[j] = file.Decls[len(file.Decls)-1]
		file.Decls = file.Decls[:len(file.Decls)-1]
	}
}