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