terraform/vendor/github.com/golang/mock/mockgen/parse.go

524 lines
14 KiB
Go

// Copyright 2012 Google Inc.
//
// 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
// This file contains the model construction by parsing source files.
import (
"errors"
"flag"
"fmt"
"go/ast"
"go/build"
"go/parser"
"go/token"
"log"
"path"
"path/filepath"
"strconv"
"strings"
"github.com/golang/mock/mockgen/model"
"golang.org/x/tools/go/packages"
)
var (
imports = flag.String("imports", "", "(source mode) Comma-separated name=path pairs of explicit imports to use.")
auxFiles = flag.String("aux_files", "", "(source mode) Comma-separated pkg=path pairs of auxiliary Go source files.")
)
// TODO: simplify error reporting
func parseFile(source string) (*model.Package, error) {
srcDir, err := filepath.Abs(filepath.Dir(source))
if err != nil {
return nil, fmt.Errorf("failed getting source directory: %v", err)
}
cfg := &packages.Config{Mode: packages.LoadSyntax, Tests: true}
pkgs, err := packages.Load(cfg, "file="+source)
if err != nil {
return nil, err
}
if packages.PrintErrors(pkgs) > 0 || len(pkgs) == 0 {
return nil, errors.New("loading package failed")
}
packageImport := pkgs[0].PkgPath
// It is illegal to import a _test package.
packageImport = strings.TrimSuffix(packageImport, "_test")
fs := token.NewFileSet()
file, err := parser.ParseFile(fs, source, nil, 0)
if err != nil {
return nil, fmt.Errorf("failed parsing source file %v: %v", source, err)
}
p := &fileParser{
fileSet: fs,
imports: make(map[string]string),
importedInterfaces: make(map[string]map[string]*ast.InterfaceType),
auxInterfaces: make(map[string]map[string]*ast.InterfaceType),
srcDir: srcDir,
}
// Handle -imports.
dotImports := make(map[string]bool)
if *imports != "" {
for _, kv := range strings.Split(*imports, ",") {
eq := strings.Index(kv, "=")
k, v := kv[:eq], kv[eq+1:]
if k == "." {
// TODO: Catch dupes?
dotImports[v] = true
} else {
// TODO: Catch dupes?
p.imports[k] = v
}
}
}
// Handle -aux_files.
if err := p.parseAuxFiles(*auxFiles); err != nil {
return nil, err
}
p.addAuxInterfacesFromFile(packageImport, file) // this file
pkg, err := p.parseFile(packageImport, file)
if err != nil {
return nil, err
}
for path := range dotImports {
pkg.DotImports = append(pkg.DotImports, path)
}
return pkg, nil
}
type fileParser struct {
fileSet *token.FileSet
imports map[string]string // package name => import path
importedInterfaces map[string]map[string]*ast.InterfaceType // package (or "") => name => interface
auxFiles []*ast.File
auxInterfaces map[string]map[string]*ast.InterfaceType // package (or "") => name => interface
srcDir string
}
func (p *fileParser) errorf(pos token.Pos, format string, args ...interface{}) error {
ps := p.fileSet.Position(pos)
format = "%s:%d:%d: " + format
args = append([]interface{}{ps.Filename, ps.Line, ps.Column}, args...)
return fmt.Errorf(format, args...)
}
func (p *fileParser) parseAuxFiles(auxFiles string) error {
auxFiles = strings.TrimSpace(auxFiles)
if auxFiles == "" {
return nil
}
for _, kv := range strings.Split(auxFiles, ",") {
parts := strings.SplitN(kv, "=", 2)
if len(parts) != 2 {
return fmt.Errorf("bad aux file spec: %v", kv)
}
pkg, fpath := parts[0], parts[1]
file, err := parser.ParseFile(p.fileSet, fpath, nil, 0)
if err != nil {
return err
}
p.auxFiles = append(p.auxFiles, file)
p.addAuxInterfacesFromFile(pkg, file)
}
return nil
}
func (p *fileParser) addAuxInterfacesFromFile(pkg string, file *ast.File) {
if _, ok := p.auxInterfaces[pkg]; !ok {
p.auxInterfaces[pkg] = make(map[string]*ast.InterfaceType)
}
for ni := range iterInterfaces(file) {
p.auxInterfaces[pkg][ni.name.Name] = ni.it
}
}
// parseFile loads all file imports and auxiliary files import into the
// fileParser, parses all file interfaces and returns package model.
func (p *fileParser) parseFile(importPath string, file *ast.File) (*model.Package, error) {
allImports, dotImports := importsOfFile(file)
// Don't stomp imports provided by -imports. Those should take precedence.
for pkg, path := range allImports {
if _, ok := p.imports[pkg]; !ok {
p.imports[pkg] = path
}
}
// Add imports from auxiliary files, which might be needed for embedded interfaces.
// Don't stomp any other imports.
for _, f := range p.auxFiles {
auxImports, _ := importsOfFile(f)
for pkg, path := range auxImports {
if _, ok := p.imports[pkg]; !ok {
p.imports[pkg] = path
}
}
}
var is []*model.Interface
for ni := range iterInterfaces(file) {
i, err := p.parseInterface(ni.name.String(), importPath, ni.it)
if err != nil {
return nil, err
}
is = append(is, i)
}
return &model.Package{
Name: file.Name.String(),
Interfaces: is,
DotImports: dotImports,
}, nil
}
// parsePackage loads package specified by path, parses it and populates
// corresponding imports and importedInterfaces into the fileParser.
func (p *fileParser) parsePackage(path string) error {
var pkgs map[string]*ast.Package
if imp, err := build.Import(path, p.srcDir, build.FindOnly); err != nil {
return err
} else if pkgs, err = parser.ParseDir(p.fileSet, imp.Dir, nil, 0); err != nil {
return err
}
for _, pkg := range pkgs {
file := ast.MergePackageFiles(pkg, ast.FilterFuncDuplicates|ast.FilterUnassociatedComments|ast.FilterImportDuplicates)
if _, ok := p.importedInterfaces[path]; !ok {
p.importedInterfaces[path] = make(map[string]*ast.InterfaceType)
}
for ni := range iterInterfaces(file) {
p.importedInterfaces[path][ni.name.Name] = ni.it
}
imports, _ := importsOfFile(file)
for pkgName, pkgPath := range imports {
if _, ok := p.imports[pkgName]; !ok {
p.imports[pkgName] = pkgPath
}
}
}
return nil
}
func (p *fileParser) parseInterface(name, pkg string, it *ast.InterfaceType) (*model.Interface, error) {
intf := &model.Interface{Name: name}
for _, field := range it.Methods.List {
switch v := field.Type.(type) {
case *ast.FuncType:
if nn := len(field.Names); nn != 1 {
return nil, fmt.Errorf("expected one name for interface %v, got %d", intf.Name, nn)
}
m := &model.Method{
Name: field.Names[0].String(),
}
var err error
m.In, m.Variadic, m.Out, err = p.parseFunc(pkg, v)
if err != nil {
return nil, err
}
intf.Methods = append(intf.Methods, m)
case *ast.Ident:
// Embedded interface in this package.
ei := p.auxInterfaces[pkg][v.String()]
if ei == nil {
if ei = p.importedInterfaces[pkg][v.String()]; ei == nil {
return nil, p.errorf(v.Pos(), "unknown embedded interface %s", v.String())
}
}
eintf, err := p.parseInterface(v.String(), pkg, ei)
if err != nil {
return nil, err
}
// Copy the methods.
// TODO: apply shadowing rules.
for _, m := range eintf.Methods {
intf.Methods = append(intf.Methods, m)
}
case *ast.SelectorExpr:
// Embedded interface in another package.
fpkg, sel := v.X.(*ast.Ident).String(), v.Sel.String()
epkg, ok := p.imports[fpkg]
if !ok {
return nil, p.errorf(v.X.Pos(), "unknown package %s", fpkg)
}
ei := p.auxInterfaces[fpkg][sel]
if ei == nil {
fpkg = epkg
if _, ok = p.importedInterfaces[epkg]; !ok {
if err := p.parsePackage(epkg); err != nil {
return nil, p.errorf(v.Pos(), "could not parse package %s: %v", fpkg, err)
}
}
if ei = p.importedInterfaces[epkg][sel]; ei == nil {
return nil, p.errorf(v.Pos(), "unknown embedded interface %s.%s", fpkg, sel)
}
}
eintf, err := p.parseInterface(sel, fpkg, ei)
if err != nil {
return nil, err
}
// Copy the methods.
// TODO: apply shadowing rules.
for _, m := range eintf.Methods {
intf.Methods = append(intf.Methods, m)
}
default:
return nil, fmt.Errorf("don't know how to mock method of type %T", field.Type)
}
}
return intf, nil
}
func (p *fileParser) parseFunc(pkg string, f *ast.FuncType) (in []*model.Parameter, variadic *model.Parameter, out []*model.Parameter, err error) {
if f.Params != nil {
regParams := f.Params.List
if isVariadic(f) {
n := len(regParams)
varParams := regParams[n-1:]
regParams = regParams[:n-1]
vp, err := p.parseFieldList(pkg, varParams)
if err != nil {
return nil, nil, nil, p.errorf(varParams[0].Pos(), "failed parsing variadic argument: %v", err)
}
variadic = vp[0]
}
in, err = p.parseFieldList(pkg, regParams)
if err != nil {
return nil, nil, nil, p.errorf(f.Pos(), "failed parsing arguments: %v", err)
}
}
if f.Results != nil {
out, err = p.parseFieldList(pkg, f.Results.List)
if err != nil {
return nil, nil, nil, p.errorf(f.Pos(), "failed parsing returns: %v", err)
}
}
return
}
func (p *fileParser) parseFieldList(pkg string, fields []*ast.Field) ([]*model.Parameter, error) {
nf := 0
for _, f := range fields {
nn := len(f.Names)
if nn == 0 {
nn = 1 // anonymous parameter
}
nf += nn
}
if nf == 0 {
return nil, nil
}
ps := make([]*model.Parameter, nf)
i := 0 // destination index
for _, f := range fields {
t, err := p.parseType(pkg, f.Type)
if err != nil {
return nil, err
}
if len(f.Names) == 0 {
// anonymous arg
ps[i] = &model.Parameter{Type: t}
i++
continue
}
for _, name := range f.Names {
ps[i] = &model.Parameter{Name: name.Name, Type: t}
i++
}
}
return ps, nil
}
func (p *fileParser) parseType(pkg string, typ ast.Expr) (model.Type, error) {
switch v := typ.(type) {
case *ast.ArrayType:
ln := -1
if v.Len != nil {
x, err := strconv.Atoi(v.Len.(*ast.BasicLit).Value)
if err != nil {
return nil, p.errorf(v.Len.Pos(), "bad array size: %v", err)
}
ln = x
}
t, err := p.parseType(pkg, v.Elt)
if err != nil {
return nil, err
}
return &model.ArrayType{Len: ln, Type: t}, nil
case *ast.ChanType:
t, err := p.parseType(pkg, v.Value)
if err != nil {
return nil, err
}
var dir model.ChanDir
if v.Dir == ast.SEND {
dir = model.SendDir
}
if v.Dir == ast.RECV {
dir = model.RecvDir
}
return &model.ChanType{Dir: dir, Type: t}, nil
case *ast.Ellipsis:
// assume we're parsing a variadic argument
return p.parseType(pkg, v.Elt)
case *ast.FuncType:
in, variadic, out, err := p.parseFunc(pkg, v)
if err != nil {
return nil, err
}
return &model.FuncType{In: in, Out: out, Variadic: variadic}, nil
case *ast.Ident:
if v.IsExported() {
// `pkg` may be an aliased imported pkg
// if so, patch the import w/ the fully qualified import
maybeImportedPkg, ok := p.imports[pkg]
if ok {
pkg = maybeImportedPkg
}
// assume type in this package
return &model.NamedType{Package: pkg, Type: v.Name}, nil
}
// assume predeclared type
return model.PredeclaredType(v.Name), nil
case *ast.InterfaceType:
if v.Methods != nil && len(v.Methods.List) > 0 {
return nil, p.errorf(v.Pos(), "can't handle non-empty unnamed interface types")
}
return model.PredeclaredType("interface{}"), nil
case *ast.MapType:
key, err := p.parseType(pkg, v.Key)
if err != nil {
return nil, err
}
value, err := p.parseType(pkg, v.Value)
if err != nil {
return nil, err
}
return &model.MapType{Key: key, Value: value}, nil
case *ast.SelectorExpr:
pkgName := v.X.(*ast.Ident).String()
pkg, ok := p.imports[pkgName]
if !ok {
return nil, p.errorf(v.Pos(), "unknown package %q", pkgName)
}
return &model.NamedType{Package: pkg, Type: v.Sel.String()}, nil
case *ast.StarExpr:
t, err := p.parseType(pkg, v.X)
if err != nil {
return nil, err
}
return &model.PointerType{Type: t}, nil
case *ast.StructType:
if v.Fields != nil && len(v.Fields.List) > 0 {
return nil, p.errorf(v.Pos(), "can't handle non-empty unnamed struct types")
}
return model.PredeclaredType("struct{}"), nil
}
return nil, fmt.Errorf("don't know how to parse type %T", typ)
}
// importsOfFile returns a map of package name to import path
// of the imports in file.
func importsOfFile(file *ast.File) (normalImports map[string]string, dotImports []string) {
normalImports = make(map[string]string)
dotImports = make([]string, 0)
for _, is := range file.Imports {
var pkgName string
importPath := is.Path.Value[1 : len(is.Path.Value)-1] // remove quotes
if is.Name != nil {
// Named imports are always certain.
if is.Name.Name == "_" {
continue
}
pkgName = is.Name.Name
} else {
pkg, err := build.Import(importPath, "", 0)
if err != nil {
// Fallback to import path suffix. Note that this is uncertain.
_, last := path.Split(importPath)
// If the last path component has dots, the first dot-delimited
// field is used as the name.
pkgName = strings.SplitN(last, ".", 2)[0]
} else {
pkgName = pkg.Name
}
}
if pkgName == "." {
dotImports = append(dotImports, importPath)
} else {
if _, ok := normalImports[pkgName]; ok {
log.Fatalf("imported package collision: %q imported twice", pkgName)
}
normalImports[pkgName] = importPath
}
}
return
}
type namedInterface struct {
name *ast.Ident
it *ast.InterfaceType
}
// Create an iterator over all interfaces in file.
func iterInterfaces(file *ast.File) <-chan namedInterface {
ch := make(chan namedInterface)
go func() {
for _, decl := range file.Decls {
gd, ok := decl.(*ast.GenDecl)
if !ok || gd.Tok != token.TYPE {
continue
}
for _, spec := range gd.Specs {
ts, ok := spec.(*ast.TypeSpec)
if !ok {
continue
}
it, ok := ts.Type.(*ast.InterfaceType)
if !ok {
continue
}
ch <- namedInterface{ts.Name, it}
}
}
close(ch)
}()
return ch
}
// isVariadic returns whether the function is variadic.
func isVariadic(f *ast.FuncType) bool {
nargs := len(f.Params.List)
if nargs == 0 {
return false
}
_, ok := f.Params.List[nargs-1].Type.(*ast.Ellipsis)
return ok
}