src/go/build/deps_test.go

   1 // Copyright 2022 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // This file exercises the import parser but also checks that
   6 // some low-level packages do not have new dependencies added.
   7
   8 package build
   9
  10 import (
  11         "bytes"
  12         "fmt"
  13         "go/token"
  14         "internal/dag"
  15         "internal/testenv"
  16         "io/fs"
  17         "os"
  18         "path/filepath"
  19         "runtime"
  20         "sort"
  21         "strings"
  22         "testing"
  23 )
  24
  25 // depsRules defines the expected dependencies between packages in
  26 // the Go source tree. It is a statement of policy.
  27 //
  28 // DO NOT CHANGE THIS DATA TO FIX BUILDS.
  29 // Existing packages should not have their constraints relaxed
  30 // without prior discussion.
  31 // Negative assertions should almost never be removed.
  32 //
  33 // "a < b" means package b can import package a.
  34 //
  35 // See `go doc internal/dag' for the full syntax.
  36 //
  37 // All-caps names are pseudo-names for specific points
  38 // in the dependency lattice.
  39 var depsRules = `
  40         # No dependencies allowed for any of these packages.
  41         NONE
  42         < constraints, container/list, container/ring,
  43           internal/cfg, internal/coverage, internal/coverage/rtcov,
  44           internal/coverage/uleb128, internal/coverage/calloc,
  45       internal/cpu, internal/goarch,
  46           internal/goexperiment, internal/goos,
  47           internal/goversion, internal/nettrace,
  48           unicode/utf8, unicode/utf16, unicode,
  49           unsafe;
  50
  51         # These packages depend only on internal/goarch and unsafe.
  52         internal/goarch, unsafe
  53         < internal/abi;
  54
  55         # RUNTIME is the core runtime group of packages, all of them very light-weight.
  56         internal/abi, internal/cpu, internal/goarch,
  57     internal/coverage/rtcov, internal/goexperiment, internal/goos, unsafe
  58         < internal/bytealg
  59         < internal/itoa
  60         < internal/unsafeheader
  61         < runtime/internal/sys
  62         < runtime/internal/syscall
  63         < runtime/internal/atomic
  64         < runtime/internal/math
  65         < runtime
  66         < sync/atomic
  67         < internal/race
  68         < sync
  69         < internal/reflectlite
  70         < errors
  71         < internal/oserror, math/bits
  72         < RUNTIME;
  73
  74         RUNTIME
  75         < sort
  76         < container/heap;
  77
  78         RUNTIME
  79         < io;
  80
  81         syscall !< io;
  82         reflect !< sort;
  83
  84         RUNTIME, unicode/utf8
  85         < path;
  86
  87         unicode !< path;
  88
  89         # SYSCALL is RUNTIME plus the packages necessary for basic system calls.
  90         RUNTIME, unicode/utf8, unicode/utf16
  91         < internal/syscall/windows/sysdll, syscall/js
  92         < syscall
  93         < internal/syscall/unix, internal/syscall/windows, internal/syscall/windows/registry
  94         < internal/syscall/execenv
  95         < SYSCALL;
  96
  97         # TIME is SYSCALL plus the core packages about time, including context.
  98         SYSCALL
  99         < time/tzdata
 100         < time
 101         < context
 102         < TIME;
 103
 104         TIME, io, path, sort
 105         < io/fs;
 106
 107         # MATH is RUNTIME plus the basic math packages.
 108         RUNTIME
 109         < math
 110         < MATH;
 111
 112         unicode !< math;
 113
 114         MATH
 115         < math/cmplx;
 116
 117         MATH
 118         < math/rand;
 119
 120         MATH
 121         < runtime/metrics;
 122
 123         MATH, unicode/utf8
 124         < strconv;
 125
 126         unicode !< strconv;
 127
 128         # STR is basic string and buffer manipulation.
 129         RUNTIME, io, unicode/utf8, unicode/utf16, unicode
 130         < bytes, strings
 131         < bufio;
 132
 133         bufio, path, strconv
 134         < STR;
 135
 136         # OS is basic OS access, including helpers (path/filepath, os/exec, etc).
 137         # OS includes string routines, but those must be layered above package os.
 138         # OS does not include reflection.
 139         io/fs
 140         < internal/testlog
 141         < internal/poll
 142         < os
 143         < os/signal;
 144
 145         io/fs
 146         < embed;
 147
 148         unicode, fmt !< net, os, os/signal;
 149
 150         os/signal, STR
 151         < path/filepath
 152         < io/ioutil;
 153
 154         os < internal/godebug;
 155
 156         path/filepath, internal/godebug < os/exec;
 157
 158         io/ioutil, os/exec, os/signal
 159         < OS;
 160
 161         reflect !< OS;
 162
 163         OS
 164         < golang.org/x/sys/cpu;
 165
 166         # FMT is OS (which includes string routines) plus reflect and fmt.
 167         # It does not include package log, which should be avoided in core packages.
 168         strconv, unicode
 169         < reflect;
 170
 171         os, reflect
 172         < internal/fmtsort
 173         < fmt;
 174
 175         OS, fmt
 176         < FMT;
 177
 178         log !< FMT;
 179
 180         # Misc packages needing only FMT.
 181         FMT
 182         < html,
 183           internal/dag,
 184           internal/goroot,
 185           mime/quotedprintable,
 186           net/internal/socktest,
 187           net/url,
 188           runtime/trace,
 189           text/scanner,
 190           text/tabwriter;
 191
 192         io, reflect
 193         < internal/saferio;
 194
 195         # encodings
 196         # core ones do not use fmt.
 197         io, strconv
 198         < encoding;
 199
 200         encoding, reflect
 201         < encoding/binary
 202         < encoding/base32, encoding/base64;
 203
 204         FMT, encoding < flag;
 205
 206         fmt !< encoding/base32, encoding/base64;
 207
 208         FMT, encoding/base32, encoding/base64, internal/saferio
 209         < encoding/ascii85, encoding/csv, encoding/gob, encoding/hex,
 210           encoding/json, encoding/pem, encoding/xml, mime;
 211
 212         # hashes
 213         io
 214         < hash
 215         < hash/adler32, hash/crc32, hash/crc64, hash/fnv, hash/maphash;
 216
 217         # math/big
 218         FMT, encoding/binary, math/rand
 219         < math/big;
 220
 221         # compression
 222         FMT, encoding/binary, hash/adler32, hash/crc32
 223         < compress/bzip2, compress/flate, compress/lzw
 224         < archive/zip, compress/gzip, compress/zlib;
 225
 226         # templates
 227         FMT
 228         < text/template/parse;
 229
 230         net/url, text/template/parse
 231         < text/template
 232         < internal/lazytemplate;
 233
 234         encoding/json, html, text/template
 235         < html/template;
 236
 237         # regexp
 238         FMT
 239         < regexp/syntax
 240         < regexp
 241         < internal/lazyregexp;
 242
 243         # suffix array
 244         encoding/binary, regexp
 245         < index/suffixarray;
 246
 247         # executable parsing
 248         FMT, encoding/binary, compress/zlib, internal/saferio
 249         < runtime/debug
 250         < debug/dwarf
 251         < debug/elf, debug/gosym, debug/macho, debug/pe, debug/plan9obj, internal/xcoff
 252         < debug/buildinfo
 253         < DEBUG;
 254
 255         # go parser and friends.
 256         FMT
 257         < go/token
 258         < go/scanner
 259         < go/ast
 260         < go/internal/typeparams
 261         < go/parser;
 262
 263         FMT
 264         < go/build/constraint, go/doc/comment;
 265
 266         go/build/constraint, go/doc/comment, go/parser, text/tabwriter
 267         < go/printer
 268         < go/format;
 269
 270         go/doc/comment, go/parser, internal/lazyregexp, text/template
 271         < go/doc;
 272
 273         math/big, go/token
 274         < go/constant;
 275
 276         container/heap, go/constant, go/parser, regexp
 277         < go/types;
 278
 279         FMT, internal/goexperiment
 280         < internal/buildcfg;
 281
 282         go/build/constraint, go/doc, go/parser, internal/buildcfg, internal/goroot, internal/goversion
 283         < go/build;
 284
 285         # databases
 286         FMT
 287         < database/sql/internal
 288         < database/sql/driver
 289         < database/sql;
 290
 291         # images
 292         FMT, compress/lzw, compress/zlib
 293         < image/color
 294         < image, image/color/palette
 295         < image/internal/imageutil
 296         < image/draw
 297         < image/gif, image/jpeg, image/png;
 298
 299         # cgo, delayed as long as possible.
 300         # If you add a dependency on CGO, you must add the package
 301         # to cgoPackages in cmd/dist/test.go as well.
 302         RUNTIME
 303         < C
 304         < runtime/cgo
 305         < CGO
 306         < runtime/msan, runtime/asan;
 307
 308         # runtime/race
 309         NONE < runtime/race/internal/amd64v1;
 310         NONE < runtime/race/internal/amd64v3;
 311         CGO, runtime/race/internal/amd64v1, runtime/race/internal/amd64v3 < runtime/race;
 312
 313         # Bulk of the standard library must not use cgo.
 314         # The prohibition stops at net and os/user.
 315         C !< fmt, go/types, CRYPTO-MATH;
 316
 317         CGO, OS
 318         < plugin;
 319
 320         CGO, FMT
 321         < os/user
 322         < archive/tar;
 323
 324         sync
 325         < internal/singleflight;
 326
 327         os
 328         < golang.org/x/net/dns/dnsmessage,
 329           golang.org/x/net/lif,
 330           golang.org/x/net/route;
 331
 332         os, runtime, strconv, sync, unsafe,
 333         internal/godebug
 334         < internal/intern;
 335
 336         internal/bytealg, internal/intern, internal/itoa, math/bits, sort, strconv
 337         < net/netip;
 338
 339         # net is unavoidable when doing any networking,
 340         # so large dependencies must be kept out.
 341         # This is a long-looking list but most of these
 342         # are small with few dependencies.
 343         CGO,
 344         golang.org/x/net/dns/dnsmessage,
 345         golang.org/x/net/lif,
 346         golang.org/x/net/route,
 347         internal/godebug,
 348         internal/nettrace,
 349         internal/poll,
 350         internal/singleflight,
 351         internal/race,
 352         net/netip,
 353         os
 354         < net;
 355
 356         fmt, unicode !< net;
 357         math/rand !< net; # net uses runtime instead
 358
 359         # NET is net plus net-helper packages.
 360         FMT, net
 361         < net/textproto;
 362
 363         mime, net/textproto, net/url
 364         < NET;
 365
 366         # logging - most packages should not import; http and up is allowed
 367         FMT
 368         < log;
 369
 370         log !< crypto/tls, database/sql, go/importer, testing;
 371
 372         FMT, log, net
 373         < log/syslog;
 374
 375         NET, log
 376         < net/mail;
 377
 378         NONE < crypto/internal/boring/sig, crypto/internal/boring/syso;
 379         sync/atomic < crypto/internal/boring/bcache, crypto/internal/boring/fipstls;
 380         crypto/internal/boring/sig, crypto/internal/boring/fipstls < crypto/tls/fipsonly;
 381
 382         # CRYPTO is core crypto algorithms - no cgo, fmt, net.
 383         # Unfortunately, stuck with reflect via encoding/binary.
 384         crypto/internal/boring/sig,
 385         crypto/internal/boring/syso,
 386         encoding/binary,
 387         golang.org/x/sys/cpu,
 388         hash, embed
 389         < crypto
 390         < crypto/subtle
 391         < crypto/internal/alias
 392         < crypto/internal/randutil
 393         < crypto/internal/nistec/fiat
 394         < crypto/internal/nistec
 395         < crypto/internal/edwards25519/field
 396         < crypto/internal/edwards25519, crypto/ecdh
 397         < crypto/cipher;
 398
 399         crypto/cipher,
 400         crypto/internal/boring/bcache
 401         < crypto/internal/boring
 402         < crypto/boring
 403         < crypto/aes, crypto/des, crypto/hmac, crypto/md5, crypto/rc4,
 404           crypto/sha1, crypto/sha256, crypto/sha512
 405         < CRYPTO;
 406
 407         CGO, fmt, net !< CRYPTO;
 408
 409         # CRYPTO-MATH is core bignum-based crypto - no cgo, net; fmt now ok.
 410         CRYPTO, FMT, math/big
 411         < crypto/internal/boring/bbig
 412         < crypto/rand
 413         < crypto/ed25519
 414         < encoding/asn1
 415         < golang.org/x/crypto/cryptobyte/asn1
 416         < golang.org/x/crypto/cryptobyte
 417         < crypto/dsa, crypto/elliptic, crypto/rsa
 418         < crypto/ecdsa
 419         < CRYPTO-MATH;
 420
 421         CGO, net !< CRYPTO-MATH;
 422
 423         # TLS, Prince of Dependencies.
 424         CRYPTO-MATH, NET, container/list, encoding/hex, encoding/pem
 425         < golang.org/x/crypto/internal/alias
 426         < golang.org/x/crypto/internal/subtle
 427         < golang.org/x/crypto/chacha20
 428         < golang.org/x/crypto/internal/poly1305
 429         < golang.org/x/crypto/chacha20poly1305
 430         < golang.org/x/crypto/hkdf
 431         < crypto/x509/internal/macos
 432         < crypto/x509/pkix;
 433
 434         crypto/internal/boring/fipstls, crypto/x509/pkix
 435         < crypto/x509
 436         < crypto/tls;
 437
 438         # crypto-aware packages
 439
 440         DEBUG, go/build, go/types, text/scanner, crypto/md5
 441         < internal/pkgbits
 442         < go/internal/gcimporter, go/internal/gccgoimporter, go/internal/srcimporter
 443         < go/importer;
 444
 445         NET, crypto/rand, mime/quotedprintable
 446         < mime/multipart;
 447
 448         crypto/tls
 449         < net/smtp;
 450
 451         # HTTP, King of Dependencies.
 452
 453         FMT
 454         < golang.org/x/net/http2/hpack
 455         < net/http/internal, net/http/internal/ascii, net/http/internal/testcert;
 456
 457         FMT, NET, container/list, encoding/binary, log
 458         < golang.org/x/text/transform
 459         < golang.org/x/text/unicode/norm
 460         < golang.org/x/text/unicode/bidi
 461         < golang.org/x/text/secure/bidirule
 462         < golang.org/x/net/idna
 463         < golang.org/x/net/http/httpguts, golang.org/x/net/http/httpproxy;
 464
 465         NET, crypto/tls
 466         < net/http/httptrace;
 467
 468         compress/gzip,
 469         golang.org/x/net/http/httpguts,
 470         golang.org/x/net/http/httpproxy,
 471         golang.org/x/net/http2/hpack,
 472         net/http/internal,
 473         net/http/internal/ascii,
 474         net/http/internal/testcert,
 475         net/http/httptrace,
 476         mime/multipart,
 477         log
 478         < net/http;
 479
 480         # HTTP-aware packages
 481
 482         encoding/json, net/http
 483         < expvar;
 484
 485         net/http, net/http/internal/ascii
 486         < net/http/cookiejar, net/http/httputil;
 487
 488         net/http, flag
 489         < net/http/httptest;
 490
 491         net/http, regexp
 492         < net/http/cgi
 493         < net/http/fcgi;
 494
 495         # Profiling
 496         FMT, compress/gzip, encoding/binary, text/tabwriter
 497         < runtime/pprof;
 498
 499         OS, compress/gzip, regexp
 500         < internal/profile;
 501
 502         html, internal/profile, net/http, runtime/pprof, runtime/trace
 503         < net/http/pprof;
 504
 505         # RPC
 506         encoding/gob, encoding/json, go/token, html/template, net/http
 507         < net/rpc
 508         < net/rpc/jsonrpc;
 509
 510         # System Information
 511         internal/cpu, sync
 512         < internal/sysinfo;
 513
 514         # Test-only
 515         log
 516         < testing/iotest
 517         < testing/fstest;
 518
 519         FMT, flag, math/rand
 520         < testing/quick;
 521
 522         FMT, DEBUG, flag, runtime/trace, internal/sysinfo, math/rand
 523         < testing;
 524
 525         FMT, crypto/sha256, encoding/json, go/ast, go/parser, go/token,
 526         internal/godebug, math/rand, encoding/hex, crypto/sha256
 527         < internal/fuzz;
 528
 529         internal/fuzz, internal/testlog, runtime/pprof, regexp
 530         < testing/internal/testdeps;
 531
 532         OS, flag, testing, internal/cfg
 533         < internal/testenv;
 534
 535         OS, encoding/base64
 536         < internal/obscuretestdata;
 537
 538         CGO, OS, fmt
 539         < os/signal/internal/pty;
 540
 541         NET, testing, math/rand
 542         < golang.org/x/net/nettest;
 543
 544         syscall
 545         < os/exec/internal/fdtest;
 546
 547         FMT, container/heap, math/rand
 548         < internal/trace;
 549
 550         FMT
 551         < internal/diff, internal/txtar;
 552
 553     FMT, os
 554     < internal/coverage/slicewriter;
 555
 556     encoding/binary, internal/unsafeheader, unsafe
 557     < internal/coverage/slicereader;
 558
 559     FMT, math, internal/coverage
 560     < internal/coverage/cmerge;
 561
 562     FMT, math, internal/coverage, internal/coverage/cmerge, text/tabwriter
 563     < internal/coverage/cformat;
 564
 565     FMT, io, internal/coverage/slicereader, internal/coverage/uleb128
 566     < internal/coverage/stringtab;
 567
 568     FMT, encoding/binary, internal/coverage, internal/coverage/stringtab,
 569     io, os, bufio, crypto/md5
 570     < internal/coverage/encodemeta;
 571
 572     FMT, bufio, encoding/binary, internal/coverage,
 573     internal/coverage/stringtab, internal/coverage/slicewriter, os, unsafe
 574     < internal/coverage/encodecounter;
 575
 576     FMT, encoding/binary, internal/coverage, io, os,
 577     internal/coverage/slicereader, internal/coverage/stringtab
 578     < internal/coverage/decodecounter;
 579
 580     FMT, encoding/binary, internal/coverage, io, os,
 581     crypto/md5, internal/coverage/stringtab
 582     < internal/coverage/decodemeta;
 583
 584     FMT, internal/coverage, os,
 585     path/filepath, regexp, sort, strconv
 586     < internal/coverage/pods;
 587
 588     FMT, bufio, crypto/md5, encoding/binary, runtime/debug,
 589     internal/coverage, internal/coverage/cmerge,
 590     internal/coverage/cformat, internal/coverage/calloc,
 591     internal/coverage/decodecounter, internal/coverage/decodemeta,
 592     internal/coverage/encodecounter, internal/coverage/encodemeta,
 593     internal/coverage/pods, os, path/filepath, reflect, time, unsafe
 594     < runtime/coverage;
 595 `
 596
 597 // listStdPkgs returns the same list of packages as "go list std".
 598 func listStdPkgs(goroot string) ([]string, error) {
 599         // Based on cmd/go's matchPackages function.
 600         var pkgs []string
 601
 602         src := filepath.Join(goroot, "src") + string(filepath.Separator)
 603         walkFn := func(path string, d fs.DirEntry, err error) error {
 604                 if err != nil || !d.IsDir() || path == src {
 605                         return nil
 606                 }
 607
 608                 base := filepath.Base(path)
 609                 if strings.HasPrefix(base, ".") || strings.HasPrefix(base, "_") || base == "testdata" {
 610                         return filepath.SkipDir
 611                 }
 612
 613                 name := filepath.ToSlash(path[len(src):])
 614                 if name == "builtin" || name == "cmd" {
 615                         return filepath.SkipDir
 616                 }
 617
 618                 pkgs = append(pkgs, strings.TrimPrefix(name, "vendor/"))
 619                 return nil
 620         }
 621         if err := filepath.WalkDir(src, walkFn); err != nil {
 622                 return nil, err
 623         }
 624         return pkgs, nil
 625 }
 626
 627 func TestDependencies(t *testing.T) {
 628         if !testenv.HasSrc() {
 629                 // Tests run in a limited file system and we do not
 630                 // provide access to every source file.
 631                 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
 632         }
 633
 634         ctxt := Default
 635         all, err := listStdPkgs(ctxt.GOROOT)
 636         if err != nil {
 637                 t.Fatal(err)
 638         }
 639         sort.Strings(all)
 640
 641         sawImport := map[string]map[string]bool{} // from package => to package => true
 642         policy := depsPolicy(t)
 643
 644         for _, pkg := range all {
 645                 imports, err := findImports(pkg)
 646                 if err != nil {
 647                         t.Error(err)
 648                         continue
 649                 }
 650                 if sawImport[pkg] == nil {
 651                         sawImport[pkg] = map[string]bool{}
 652                 }
 653                 var bad []string
 654                 for _, imp := range imports {
 655                         sawImport[pkg][imp] = true
 656                         if !policy.HasEdge(pkg, imp) {
 657                                 bad = append(bad, imp)
 658                         }
 659                 }
 660                 if bad != nil {
 661                         t.Errorf("unexpected dependency: %s imports %v", pkg, bad)
 662                 }
 663         }
 664 }
 665
 666 var buildIgnore = []byte("\n//go:build ignore")
 667
 668 func findImports(pkg string) ([]string, error) {
 669         vpkg := pkg
 670         if strings.HasPrefix(pkg, "golang.org") {
 671                 vpkg = "vendor/" + pkg
 672         }
 673         dir := filepath.Join(Default.GOROOT, "src", vpkg)
 674         files, err := os.ReadDir(dir)
 675         if err != nil {
 676                 return nil, err
 677         }
 678         var imports []string
 679         var haveImport = map[string]bool{}
 680         if pkg == "crypto/internal/boring" {
 681                 haveImport["C"] = true // kludge: prevent C from appearing in crypto/internal/boring imports
 682         }
 683         fset := token.NewFileSet()
 684         for _, file := range files {
 685                 name := file.Name()
 686                 if name == "slice_go14.go" || name == "slice_go18.go" {
 687                         // These files are for compiler bootstrap with older versions of Go and not built in the standard build.
 688                         continue
 689                 }
 690                 if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
 691                         continue
 692                 }
 693                 info := fileInfo{
 694                         name: filepath.Join(dir, name),
 695                         fset: fset,
 696                 }
 697                 f, err := os.Open(info.name)
 698                 if err != nil {
 699                         return nil, err
 700                 }
 701                 err = readGoInfo(f, &info)
 702                 f.Close()
 703                 if err != nil {
 704                         return nil, fmt.Errorf("reading %v: %v", name, err)
 705                 }
 706                 if info.parsed.Name.Name == "main" {
 707                         continue
 708                 }
 709                 if bytes.Contains(info.header, buildIgnore) {
 710                         continue
 711                 }
 712                 for _, imp := range info.imports {
 713                         path := imp.path
 714                         if !haveImport[path] {
 715                                 haveImport[path] = true
 716                                 imports = append(imports, path)
 717                         }
 718                 }
 719         }
 720         sort.Strings(imports)
 721         return imports, nil
 722 }
 723
 724 // depsPolicy returns a map m such that m[p][d] == true when p can import d.
 725 func depsPolicy(t *testing.T) *dag.Graph {
 726         g, err := dag.Parse(depsRules)
 727         if err != nil {
 728                 t.Fatal(err)
 729         }
 730         return g
 731 }
 732
 733 // TestStdlibLowercase tests that all standard library package names are
 734 // lowercase. See Issue 40065.
 735 func TestStdlibLowercase(t *testing.T) {
 736         if !testenv.HasSrc() {
 737                 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
 738         }
 739
 740         ctxt := Default
 741         all, err := listStdPkgs(ctxt.GOROOT)
 742         if err != nil {
 743                 t.Fatal(err)
 744         }
 745
 746         for _, pkgname := range all {
 747                 if strings.ToLower(pkgname) != pkgname {
 748                         t.Errorf("package %q should not use upper-case path", pkgname)
 749                 }
 750         }
 751 }
 752
 753 // TestFindImports tests that findImports works.  See #43249.
 754 func TestFindImports(t *testing.T) {
 755         imports, err := findImports("go/build")
 756         if err != nil {
 757                 t.Fatal(err)
 758         }
 759         t.Logf("go/build imports %q", imports)
 760         want := []string{"bytes", "os", "path/filepath", "strings"}
 761 wantLoop:
 762         for _, w := range want {
 763                 for _, imp := range imports {
 764                         if imp == w {
 765                                 continue wantLoop
 766                         }
 767                 }
 768                 t.Errorf("expected to find %q in import list", w)
 769         }
 770 }