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/cipher;
 399
 400         crypto/cipher,
 401         crypto/internal/boring/bcache
 402         < crypto/internal/boring
 403         < crypto/boring;
 404
 405         crypto/internal/alias
 406         < crypto/internal/randutil
 407         < crypto/internal/nistec/fiat
 408         < crypto/internal/nistec
 409         < crypto/internal/edwards25519/field
 410         < crypto/internal/edwards25519;
 411
 412         crypto/boring
 413         < crypto/aes, crypto/des, crypto/hmac, crypto/md5, crypto/rc4,
 414           crypto/sha1, crypto/sha256, crypto/sha512;
 415
 416         crypto/boring, crypto/internal/edwards25519/field
 417         < crypto/ecdh;
 418
 419         crypto/aes,
 420         crypto/des,
 421         crypto/ecdh,
 422         crypto/hmac,
 423         crypto/internal/edwards25519,
 424         crypto/md5,
 425         crypto/rc4,
 426         crypto/sha1,
 427         crypto/sha256,
 428         crypto/sha512
 429         < CRYPTO;
 430
 431         CGO, fmt, net !< CRYPTO;
 432
 433         # CRYPTO-MATH is core bignum-based crypto - no cgo, net; fmt now ok.
 434         CRYPTO, FMT, math/big
 435         < crypto/internal/boring/bbig
 436         < crypto/rand
 437         < crypto/ed25519
 438         < encoding/asn1
 439         < golang.org/x/crypto/cryptobyte/asn1
 440         < golang.org/x/crypto/cryptobyte
 441         < crypto/dsa, crypto/elliptic, crypto/rsa
 442         < crypto/ecdsa
 443         < CRYPTO-MATH;
 444
 445         CGO, net !< CRYPTO-MATH;
 446
 447         # TLS, Prince of Dependencies.
 448         CRYPTO-MATH, NET, container/list, encoding/hex, encoding/pem
 449         < golang.org/x/crypto/internal/alias
 450         < golang.org/x/crypto/internal/subtle
 451         < golang.org/x/crypto/chacha20
 452         < golang.org/x/crypto/internal/poly1305
 453         < golang.org/x/crypto/chacha20poly1305
 454         < golang.org/x/crypto/hkdf
 455         < crypto/x509/internal/macos
 456         < crypto/x509/pkix;
 457
 458         crypto/internal/boring/fipstls, crypto/x509/pkix
 459         < crypto/x509
 460         < crypto/tls;
 461
 462         # crypto-aware packages
 463
 464         DEBUG, go/build, go/types, text/scanner, crypto/md5
 465         < internal/pkgbits
 466         < go/internal/gcimporter, go/internal/gccgoimporter, go/internal/srcimporter
 467         < go/importer;
 468
 469         NET, crypto/rand, mime/quotedprintable
 470         < mime/multipart;
 471
 472         crypto/tls
 473         < net/smtp;
 474
 475         # HTTP, King of Dependencies.
 476
 477         FMT
 478         < golang.org/x/net/http2/hpack
 479         < net/http/internal, net/http/internal/ascii, net/http/internal/testcert;
 480
 481         FMT, NET, container/list, encoding/binary, log
 482         < golang.org/x/text/transform
 483         < golang.org/x/text/unicode/norm
 484         < golang.org/x/text/unicode/bidi
 485         < golang.org/x/text/secure/bidirule
 486         < golang.org/x/net/idna
 487         < golang.org/x/net/http/httpguts, golang.org/x/net/http/httpproxy;
 488
 489         NET, crypto/tls
 490         < net/http/httptrace;
 491
 492         compress/gzip,
 493         golang.org/x/net/http/httpguts,
 494         golang.org/x/net/http/httpproxy,
 495         golang.org/x/net/http2/hpack,
 496         net/http/internal,
 497         net/http/internal/ascii,
 498         net/http/internal/testcert,
 499         net/http/httptrace,
 500         mime/multipart,
 501         log
 502         < net/http;
 503
 504         # HTTP-aware packages
 505
 506         encoding/json, net/http
 507         < expvar;
 508
 509         net/http, net/http/internal/ascii
 510         < net/http/cookiejar, net/http/httputil;
 511
 512         net/http, flag
 513         < net/http/httptest;
 514
 515         net/http, regexp
 516         < net/http/cgi
 517         < net/http/fcgi;
 518
 519         # Profiling
 520         FMT, compress/gzip, encoding/binary, text/tabwriter
 521         < runtime/pprof;
 522
 523         OS, compress/gzip, regexp
 524         < internal/profile;
 525
 526         html, internal/profile, net/http, runtime/pprof, runtime/trace
 527         < net/http/pprof;
 528
 529         # RPC
 530         encoding/gob, encoding/json, go/token, html/template, net/http
 531         < net/rpc
 532         < net/rpc/jsonrpc;
 533
 534         # System Information
 535         internal/cpu, sync
 536         < internal/sysinfo;
 537
 538         # Test-only
 539         log
 540         < testing/iotest
 541         < testing/fstest;
 542
 543         FMT, flag, math/rand
 544         < testing/quick;
 545
 546         FMT, DEBUG, flag, runtime/trace, internal/sysinfo, math/rand
 547         < testing;
 548
 549         FMT, crypto/sha256, encoding/json, go/ast, go/parser, go/token,
 550         internal/godebug, math/rand, encoding/hex, crypto/sha256
 551         < internal/fuzz;
 552
 553         internal/fuzz, internal/testlog, runtime/pprof, regexp
 554         < testing/internal/testdeps;
 555
 556         OS, flag, testing, internal/cfg, internal/platform, internal/goroot
 557         < internal/testenv;
 558
 559         OS, encoding/base64
 560         < internal/obscuretestdata;
 561
 562         CGO, OS, fmt
 563         < os/signal/internal/pty;
 564
 565         NET, testing, math/rand
 566         < golang.org/x/net/nettest;
 567
 568         syscall
 569         < os/exec/internal/fdtest;
 570
 571         FMT, container/heap, math/rand
 572         < internal/trace;
 573
 574         FMT
 575         < internal/diff, internal/txtar;
 576
 577         FMT, crypto/md5, encoding/binary, regexp, sort, text/tabwriter, unsafe,
 578         internal/coverage, internal/coverage/uleb128
 579         < internal/coverage/cmerge,
 580           internal/coverage/pods,
 581           internal/coverage/slicereader,
 582           internal/coverage/slicewriter;
 583
 584         internal/coverage/slicereader, internal/coverage/slicewriter
 585         < internal/coverage/stringtab
 586         < internal/coverage/decodecounter, internal/coverage/decodemeta,
 587           internal/coverage/encodecounter, internal/coverage/encodemeta;
 588
 589         internal/coverage/cmerge
 590         < internal/coverage/cformat;
 591
 592         runtime/debug,
 593         internal/coverage/calloc,
 594         internal/coverage/cformat,
 595         internal/coverage/decodecounter, internal/coverage/decodemeta,
 596         internal/coverage/encodecounter, internal/coverage/encodemeta,
 597         internal/coverage/pods
 598         < runtime/coverage;
 599 `
 600
 601 // listStdPkgs returns the same list of packages as "go list std".
 602 func listStdPkgs(goroot string) ([]string, error) {
 603         // Based on cmd/go's matchPackages function.
 604         var pkgs []string
 605
 606         src := filepath.Join(goroot, "src") + string(filepath.Separator)
 607         walkFn := func(path string, d fs.DirEntry, err error) error {
 608                 if err != nil || !d.IsDir() || path == src {
 609                         return nil
 610                 }
 611
 612                 base := filepath.Base(path)
 613                 if strings.HasPrefix(base, ".") || strings.HasPrefix(base, "_") || base == "testdata" {
 614                         return filepath.SkipDir
 615                 }
 616
 617                 name := filepath.ToSlash(path[len(src):])
 618                 if name == "builtin" || name == "cmd" {
 619                         return filepath.SkipDir
 620                 }
 621
 622                 pkgs = append(pkgs, strings.TrimPrefix(name, "vendor/"))
 623                 return nil
 624         }
 625         if err := filepath.WalkDir(src, walkFn); err != nil {
 626                 return nil, err
 627         }
 628         return pkgs, nil
 629 }
 630
 631 func TestDependencies(t *testing.T) {
 632         if !testenv.HasSrc() {
 633                 // Tests run in a limited file system and we do not
 634                 // provide access to every source file.
 635                 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
 636         }
 637
 638         ctxt := Default
 639         all, err := listStdPkgs(ctxt.GOROOT)
 640         if err != nil {
 641                 t.Fatal(err)
 642         }
 643         sort.Strings(all)
 644
 645         sawImport := map[string]map[string]bool{} // from package => to package => true
 646         policy := depsPolicy(t)
 647
 648         for _, pkg := range all {
 649                 imports, err := findImports(pkg)
 650                 if err != nil {
 651                         t.Error(err)
 652                         continue
 653                 }
 654                 if sawImport[pkg] == nil {
 655                         sawImport[pkg] = map[string]bool{}
 656                 }
 657                 var bad []string
 658                 for _, imp := range imports {
 659                         sawImport[pkg][imp] = true
 660                         if !policy.HasEdge(pkg, imp) {
 661                                 bad = append(bad, imp)
 662                         }
 663                 }
 664                 if bad != nil {
 665                         t.Errorf("unexpected dependency: %s imports %v", pkg, bad)
 666                 }
 667         }
 668 }
 669
 670 var buildIgnore = []byte("\n//go:build ignore")
 671
 672 func findImports(pkg string) ([]string, error) {
 673         vpkg := pkg
 674         if strings.HasPrefix(pkg, "golang.org") {
 675                 vpkg = "vendor/" + pkg
 676         }
 677         dir := filepath.Join(Default.GOROOT, "src", vpkg)
 678         files, err := os.ReadDir(dir)
 679         if err != nil {
 680                 return nil, err
 681         }
 682         var imports []string
 683         var haveImport = map[string]bool{}
 684         if pkg == "crypto/internal/boring" {
 685                 haveImport["C"] = true // kludge: prevent C from appearing in crypto/internal/boring imports
 686         }
 687         fset := token.NewFileSet()
 688         for _, file := range files {
 689                 name := file.Name()
 690                 if name == "slice_go14.go" || name == "slice_go18.go" {
 691                         // These files are for compiler bootstrap with older versions of Go and not built in the standard build.
 692                         continue
 693                 }
 694                 if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
 695                         continue
 696                 }
 697                 info := fileInfo{
 698                         name: filepath.Join(dir, name),
 699                         fset: fset,
 700                 }
 701                 f, err := os.Open(info.name)
 702                 if err != nil {
 703                         return nil, err
 704                 }
 705                 err = readGoInfo(f, &info)
 706                 f.Close()
 707                 if err != nil {
 708                         return nil, fmt.Errorf("reading %v: %v", name, err)
 709                 }
 710                 if info.parsed.Name.Name == "main" {
 711                         continue
 712                 }
 713                 if bytes.Contains(info.header, buildIgnore) {
 714                         continue
 715                 }
 716                 for _, imp := range info.imports {
 717                         path := imp.path
 718                         if !haveImport[path] {
 719                                 haveImport[path] = true
 720                                 imports = append(imports, path)
 721                         }
 722                 }
 723         }
 724         sort.Strings(imports)
 725         return imports, nil
 726 }
 727
 728 // depsPolicy returns a map m such that m[p][d] == true when p can import d.
 729 func depsPolicy(t *testing.T) *dag.Graph {
 730         g, err := dag.Parse(depsRules)
 731         if err != nil {
 732                 t.Fatal(err)
 733         }
 734         return g
 735 }
 736
 737 // TestStdlibLowercase tests that all standard library package names are
 738 // lowercase. See Issue 40065.
 739 func TestStdlibLowercase(t *testing.T) {
 740         if !testenv.HasSrc() {
 741                 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
 742         }
 743
 744         ctxt := Default
 745         all, err := listStdPkgs(ctxt.GOROOT)
 746         if err != nil {
 747                 t.Fatal(err)
 748         }
 749
 750         for _, pkgname := range all {
 751                 if strings.ToLower(pkgname) != pkgname {
 752                         t.Errorf("package %q should not use upper-case path", pkgname)
 753                 }
 754         }
 755 }
 756
 757 // TestFindImports tests that findImports works.  See #43249.
 758 func TestFindImports(t *testing.T) {
 759         imports, err := findImports("go/build")
 760         if err != nil {
 761                 t.Fatal(err)
 762         }
 763         t.Logf("go/build imports %q", imports)
 764         want := []string{"bytes", "os", "path/filepath", "strings"}
 765 wantLoop:
 766         for _, w := range want {
 767                 for _, imp := range imports {
 768                         if imp == w {
 769                                 continue wantLoop
 770                         }
 771                 }
 772                 t.Errorf("expected to find %q in import list", w)
 773         }
 774 }