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