Golang Config.Load方法代碼示例

func main() {
	// Loader is a tool for opening Go files, it loads from a Config type
	conf := loader.Config{
		Build: &build.Default,
	}

	path, _ := filepath.Abs("looper")
	file, err := conf.ParseFile(path+"/"+"looper.go", nil)
	if err != nil {
		fmt.Println(err)
		return
	}

	// Creation of a single file main pacakge
	conf.CreateFromFiles("looper", file)
	conf.Import("runtime")

	p, err := conf.Load()
	if err != nil {
		fmt.Println(err)
		return
	}

	// Finally, create SSA representation from the package we've loaded
	program := ssautil.CreateProgram(p, ssa.SanityCheckFunctions)
	looperPkg := program.Package(p.Created[0].Pkg)

	fmt.Println("RIGHT IN THE SINGLE STATIC ASSIGNMENT FORM:")
	looperPkg.WriteTo(os.Stdout)

	fmt.Println("LOOK AT THIS HERE LOOPER FUNC:")
	looperFunc := looperPkg.Func("Looper")
	looperFunc.WriteTo(os.Stdout)
}

func loadProgram(args []string, tests bool) (*ssa.Program, error) {
	conf := loader.Config{}

	if len(args) == 0 {
		fmt.Fprintln(os.Stderr, Usage)
		os.Exit(1)
	}

	// Use the initial packages from the command line.
	args, err := conf.FromArgs(args, tests)
	if err != nil {
		return nil, err
	}

	// Load, parse and type-check the whole program.
	iprog, err := conf.Load()
	if err != nil {
		return nil, err
	}

	// Create and build SSA-form program representation.
	prog := ssautil.CreateProgram(iprog, 0)
	prog.BuildAll()
	return prog, nil
}

// Return count of unused vars
func myloader(args []string) (count int) {
	var conf loader.Config
	conf.FromArgs(args, false)
	prog, err := conf.Load()
	if err != nil {
		log.Fatal(err)
	}

	for _, pi := range prog.Created {
		fmt.Println(pi)
	}

	info := prog.Package(args[0]).Info
	fset := prog.Fset

	ssaprog := ssautil.CreateProgram(prog, ssa.GlobalDebug)
	ssaprog.Build()

	for expr, object := range info.Defs {
		unused := checkObj(expr, object, prog, ssaprog, fset)
		if unused {
			fmt.Fprintf(os.Stderr, "Unused assignment for '%v' %v\n", expr, fset.Position(expr.Pos()))
			count++
		}
	}
	for expr, object := range info.Uses {
		unused := checkObj(expr, object, prog, ssaprog, fset)
		if unused {
			fmt.Fprintf(os.Stderr, "Unused assignment for '%v' %v\n", expr, fset.Position(expr.Pos()))
			count++
		}
	}
	return count
}

func TestLoad_FromImports_Success(t *testing.T) {
	var conf loader.Config
	conf.ImportWithTests("fmt")
	conf.ImportWithTests("errors")

	prog, err := conf.Load()
	if err != nil {
		t.Errorf("Load failed unexpectedly: %v", err)
	}
	if prog == nil {
		t.Fatalf("Load returned a nil Program")
	}
	if got, want := created(prog), "errors_test fmt_test"; got != want {
		t.Errorf("Created = %q, want %s", got, want)
	}
	if got, want := imported(prog), "errors fmt"; got != want {
		t.Errorf("Imported = %s, want %s", got, want)
	}
	// Check set of transitive packages.
	// There are >30 and the set may grow over time, so only check a few.
	want := map[string]bool{
		"strings": true,
		"time":    true,
		"runtime": true,
		"testing": true,
		"unicode": true,
	}
	for _, path := range all(prog) {
		delete(want, path)
	}
	if len(want) > 0 {
		t.Errorf("AllPackages is missing these keys: %q", keys(want))
	}
}

func TestLoad_ParseError_AllowErrors(t *testing.T) {
	var conf loader.Config
	conf.AllowErrors = true
	conf.CreateFromFilenames("badpkg", "testdata/badpkgdecl.go")

	prog, err := conf.Load()
	if err != nil {
		t.Errorf("Load failed unexpectedly: %v", err)
	}
	if prog == nil {
		t.Fatalf("Load returned a nil Program")
	}
	if got, want := created(prog), "badpkg"; got != want {
		t.Errorf("Created = %s, want %s", got, want)
	}

	badpkg := prog.Created[0]
	if len(badpkg.Files) != 1 {
		t.Errorf("badpkg has %d files, want 1", len(badpkg.Files))
	}
	wantErr := filepath.Join("testdata", "badpkgdecl.go") + ":1:34: expected 'package', found 'EOF'"
	if !hasError(badpkg.Errors, wantErr) {
		t.Errorf("badpkg.Errors = %v, want %s", badpkg.Errors, wantErr)
	}
}

// loadWithSoftErrors calls lconf.Load, suppressing "soft" errors.  (See Go issue 16530.)
// TODO(adonovan): Once the loader has an option to allow soft errors,
// replace calls to loadWithSoftErrors with loader calls with that parameter.
func loadWithSoftErrors(lconf *loader.Config) (*loader.Program, error) {
	lconf.AllowErrors = true

	// Ideally we would just return conf.Load() here, but go/types
	// reports certain "soft" errors that gc does not (Go issue 14596).
	// As a workaround, we set AllowErrors=true and then duplicate
	// the loader's error checking but allow soft errors.
	// It would be nice if the loader API permitted "AllowErrors: soft".
	prog, err := lconf.Load()
	if err != nil {
		return nil, err
	}
	var errpkgs []string
	// Report hard errors in indirectly imported packages.
	for _, info := range prog.AllPackages {
		if containsHardErrors(info.Errors) {
			errpkgs = append(errpkgs, info.Pkg.Path())
		} else {
			// Enable SSA construction for packages containing only soft errors.
			info.TransitivelyErrorFree = true
		}
	}
	if errpkgs != nil {
		var more string
		if len(errpkgs) > 3 {
			more = fmt.Sprintf(" and %d more", len(errpkgs)-3)
			errpkgs = errpkgs[:3]
		}
		return nil, fmt.Errorf("couldn't load packages due to errors: %s%s",
			strings.Join(errpkgs, ", "), more)
	}
	return prog, err
}

func TestCwd(t *testing.T) {
	ctxt := fakeContext(map[string]string{"one/two/three": `package three`})
	for _, test := range []struct {
		cwd, arg, want string
	}{
		{cwd: "/go/src/one", arg: "./two/three", want: "one/two/three"},
		{cwd: "/go/src/one", arg: "../one/two/three", want: "one/two/three"},
		{cwd: "/go/src/one", arg: "one/two/three", want: "one/two/three"},
		{cwd: "/go/src/one/two/three", arg: ".", want: "one/two/three"},
		{cwd: "/go/src/one", arg: "two/three", want: ""},
	} {
		conf := loader.Config{
			Cwd:   test.cwd,
			Build: ctxt,
		}
		conf.Import(test.arg)

		var got string
		prog, err := conf.Load()
		if prog != nil {
			got = imported(prog)
		}
		if got != test.want {
			t.Errorf("Load(%s) from %s: Imported = %s, want %s",
				test.arg, test.cwd, got, test.want)
			if err != nil {
				t.Errorf("Load failed: %v", err)
			}
		}
	}
}

func TestStdlib(t *testing.T) {
	defer func(saved func(format string, args ...interface{})) {
		logf = saved
	}(logf)
	logf = t.Errorf

	ctxt := build.Default // copy

	// Enumerate $GOROOT packages.
	saved := ctxt.GOPATH
	ctxt.GOPATH = "" // disable GOPATH during AllPackages
	pkgs := buildutil.AllPackages(&ctxt)
	ctxt.GOPATH = saved

	// Throw in a number of go.tools packages too.
	pkgs = append(pkgs,
		"golang.org/x/tools/cmd/godoc",
		"golang.org/x/tools/refactor/lexical")

	// Load, parse and type-check the program.
	conf := loader.Config{Build: &ctxt}
	for _, path := range pkgs {
		conf.ImportWithTests(path)
	}
	iprog, err := conf.Load()
	if err != nil {
		t.Fatalf("Load failed: %v", err)
	}

	// This test ensures that Structure doesn't panic and that
	// its internal sanity-checks against go/types don't fail.
	for pkg, info := range iprog.AllPackages {
		_ = Structure(iprog.Fset, pkg, &info.Info, info.Files)
	}
}

// This example imports three packages, including the tests for one of
// them, and loads all their dependencies.
func ExampleConfig_Import() {
	// ImportWithTest("strconv") causes strconv to include
	// internal_test.go, and creates an external test package,
	// strconv_test.
	// (Compare with the example of CreateFromFiles.)

	var conf loader.Config
	conf.Import("unicode/utf8")
	conf.Import("errors")
	conf.ImportWithTests("strconv")
	prog, err := conf.Load()
	if err != nil {
		log.Fatal(err)
	}

	printProgram(prog)
	printFilenames(prog.Fset, prog.Package("strconv"))
	printFilenames(prog.Fset, prog.Package("strconv_test"))
	// Output:
	// created: [strconv_test]
	// imported: [errors strconv unicode/utf8]
	// initial: [errors strconv strconv_test unicode/utf8]
	// all: [bufio bytes errors flag fmt io log math math/rand os reflect runtime runtime/pprof runtime/trace sort strconv strconv_test strings sync sync/atomic syscall testing text/tabwriter time unicode unicode/utf8]
	// strconv.Files: [atob.go atof.go atoi.go decimal.go doc.go extfloat.go ftoa.go isprint.go itoa.go quote.go internal_test.go]
	// strconv_test.Files: [atob_test.go atof_test.go atoi_test.go decimal_test.go example_test.go fp_test.go ftoa_test.go itoa_test.go quote_test.go strconv_test.go]
}

// loadProgram loads the specified set of packages (plus their tests)
// and all their dependencies, from source, through the specified build
// context.  Only packages in pkgs will have their functions bodies typechecked.
func loadProgram(ctxt *build.Context, pkgs map[string]bool) (*loader.Program, error) {
	conf := loader.Config{
		Build:         ctxt,
		SourceImports: true,
		ParserMode:    parser.ParseComments,

		// TODO(adonovan): enable this.  Requires making a lot of code more robust!
		AllowErrors: false,
	}

	// Optimization: don't type-check the bodies of functions in our
	// dependencies, since we only need exported package members.
	conf.TypeCheckFuncBodies = func(p string) bool {
		return pkgs[p] || pkgs[strings.TrimSuffix(p, "_test")]
	}

	if Verbose {
		var list []string
		for pkg := range pkgs {
			list = append(list, pkg)
		}
		sort.Strings(list)
		for _, pkg := range list {
			fmt.Fprintf(os.Stderr, "Loading package: %s\n", pkg)
		}
	}

	for pkg := range pkgs {
		if err := conf.ImportWithTests(pkg); err != nil {
			return nil, err
		}
	}
	return conf.Load()
}

func main() {
	flag.Parse()

	importPaths := gotool.ImportPaths(flag.Args())
	if len(importPaths) == 0 {
		return
	}

	var conf loader.Config
	conf.Fset = fset
	for _, importPath := range importPaths {
		conf.Import(importPath)
	}
	prog, err := conf.Load()
	if err != nil {
		log.Fatal(err)
	}

	for _, pkg := range prog.InitialPackages() {
		for _, file := range pkg.Files {
			ast.Inspect(file, func(node ast.Node) bool {
				if s, ok := node.(*ast.StructType); ok {
					malign(node.Pos(), pkg.Types[s].Type.(*types.Struct))
				}
				return true
			})
		}
	}
}

// Create unexporter
func NewUnexporter(o *Config) (*unexporter, error) {

	var conf loader.Config
	for _, package_name := range buildutil.AllPackages(&build.Default) {
		conf.ImportWithTests(package_name)
	}
	program, err := conf.Load()
	if err != nil {
		return nil, err
	}

	if program.Package(o.Pkg) == nil {
		return nil, errors.New(fmt.Sprintf("'%s' is not a valid package", o.Pkg))
	}

	if o.Debug {
		pkg := program.Package(o.Pkg).Pkg
		fmt.Printf("finding unused identifiers for %s (%s)\n", pkg.Name(), pkg.Path())
	}

	unexporter := &unexporter{
		Program:     program,
		MainPackage: program.Package(o.Pkg),
		Verbose:     o.Debug,
	}

	unexporter.run()

	return unexporter, nil

}

func TestTransitivelyErrorFreeFlag(t *testing.T) {
	// Create an minimal custom build.Context
	// that fakes the following packages:
	//
	// a --> b --> c!   c has an error
	//   \              d and e are transitively error-free.
	//    e --> d
	//
	// Each package [a-e] consists of one file, x.go.
	pkgs := map[string]string{
		"a": `package a; import (_ "b"; _ "e")`,
		"b": `package b; import _ "c"`,
		"c": `package c; func f() { _ = int(false) }`, // type error within function body
		"d": `package d;`,
		"e": `package e; import _ "d"`,
	}
	conf := loader.Config{
		AllowErrors:   true,
		SourceImports: true,
		Build:         fakeContext(pkgs),
	}
	conf.Import("a")

	prog, err := conf.Load()
	if err != nil {
		t.Errorf("Load failed: %s", err)
	}
	if prog == nil {
		t.Fatalf("Load returned nil *Program")
	}

	for pkg, info := range prog.AllPackages {
		var wantErr, wantTEF bool
		switch pkg.Path() {
		case "a", "b":
		case "c":
			wantErr = true
		case "d", "e":
			wantTEF = true
		default:
			t.Errorf("unexpected package: %q", pkg.Path())
			continue
		}

		if (info.Errors != nil) != wantErr {
			if wantErr {
				t.Errorf("Package %q.Error = nil, want error", pkg.Path())
			} else {
				t.Errorf("Package %q has unexpected Errors: %v",
					pkg.Path(), info.Errors)
			}
		}

		if info.TransitivelyErrorFree != wantTEF {
			t.Errorf("Package %q.TransitivelyErrorFree=%t, want %t",
				pkg.Path(), info.TransitivelyErrorFree, wantTEF)
		}
	}
}

func (p *Parser) Parse(path string) error {
	dir := filepath.Dir(path)

	files, err := ioutil.ReadDir(dir)
	if err != nil {
		fmt.Printf("// [ERROR] Parse(%s) -> ioutil.ReadDir(%#v) -> err=<%#v>\n", path, dir, err)
		return err
	}

	var astFiles []*ast.File
	var conf loader.Config

	conf.TypeCheckFuncBodies = func(_ string) bool { return false }
	conf.TypeChecker.DisableUnusedImportCheck = true
	conf.TypeChecker.Importer = importer.Default()

	for _, fi := range files {
		if filepath.Ext(fi.Name()) != ".go" {
			continue
		}

		fpath := filepath.Join(dir, fi.Name())
		f, err := conf.ParseFile(fpath, nil)
		if err != nil {
			fmt.Printf("// [ERROR] Parse(%s) -> conf.ParseFile(%#v) -> err=<%#v>\n", path, fpath, err)
			return err
		}

		if fi.Name() == filepath.Base(path) {
			p.file = f
		}

		astFiles = append(astFiles, f)
	}

	abs, err := filepath.Abs(path)
	if err != nil {
		fmt.Printf("// [ERROR] Parse(%s) -> filepath.Abs(%#v) -> err=<%#v>\n", path, path, err)
		return err
	}

	// Type-check a package consisting of this file.
	// Type information for the imported packages
	// comes from $GOROOT/pkg/$GOOS_$GOOARCH/fmt.a.
	conf.CreateFromFiles(abs, astFiles...)

	prog, err := conf.Load()
	if err != nil {
		fmt.Printf("// [ERROR] Parse(%s) -> conf.Load() -> err=<%#v>\n", path, err)
		return err
	} else if len(prog.Created) != 1 {
		panic("expected only one Created package")
	}

	p.path = abs
	p.pkg = prog.Created[0].Pkg

	return nil
}

// createProgram returns a program containing packages specified.
func createProgram(packages ...string) (*loader.Program, error) {
	var conf loader.Config

	for _, name := range packages {
		conf.CreateFromFilenames(name, getFileNames(name)...)
	}
	return conf.Load()
}