src/go/build/deps_test.go

   1 // Copyright 2012 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/cpu, internal/goarch,
  44           internal/goexperiment, internal/goos,
  45           internal/goversion, internal/nettrace,
  46           unicode/utf8, unicode/utf16, unicode,
  47           unsafe;
  48
  49         # These packages depend only on internal/goarch and unsafe.
  50         internal/goarch, unsafe
  51         < internal/abi;
  52
  53         # RUNTIME is the core runtime group of packages, all of them very light-weight.
  54         internal/abi, internal/cpu, internal/goarch,
  55         internal/goexperiment, internal/goos, unsafe
  56         < internal/bytealg
  57         < internal/itoa
  58         < internal/unsafeheader
  59         < runtime/internal/sys
  60         < runtime/internal/syscall
  61         < runtime/internal/atomic
  62         < runtime/internal/math
  63         < runtime
  64         < sync/atomic
  65         < internal/race
  66         < sync
  67         < internal/reflectlite
  68         < errors
  69         < internal/oserror, math/bits
  70         < RUNTIME;
  71
  72         RUNTIME
  73         < sort
  74         < container/heap;
  75
  76         RUNTIME
  77         < io;
  78
  79         syscall !< io;
  80         reflect !< sort;
  81
  82         RUNTIME, unicode/utf8
  83         < path;
  84
  85         unicode !< path;
  86
  87         # SYSCALL is RUNTIME plus the packages necessary for basic system calls.
  88         RUNTIME, unicode/utf8, unicode/utf16
  89         < internal/syscall/windows/sysdll, syscall/js
  90         < syscall
  91         < internal/syscall/unix, internal/syscall/windows, internal/syscall/windows/registry
  92         < internal/syscall/execenv
  93         < SYSCALL;
  94
  95         # TIME is SYSCALL plus the core packages about time, including context.
  96         SYSCALL
  97         < time/tzdata
  98         < time
  99         < context
 100         < TIME;
 101
 102         TIME, io, path, sort
 103         < io/fs;
 104
 105         # MATH is RUNTIME plus the basic math packages.
 106         RUNTIME
 107         < math
 108         < MATH;
 109
 110         unicode !< math;
 111
 112         MATH
 113         < math/cmplx;
 114
 115         MATH
 116         < math/rand;
 117
 118         MATH
 119         < runtime/metrics;
 120
 121         MATH, unicode/utf8
 122         < strconv;
 123
 124         unicode !< strconv;
 125
 126         io
 127         < internal/saferio;
 128
 129         # STR is basic string and buffer manipulation.
 130         RUNTIME, io, unicode/utf8, unicode/utf16, unicode
 131         < bytes, strings
 132         < bufio;
 133
 134         bufio, path, strconv
 135         < STR;
 136
 137         # OS is basic OS access, including helpers (path/filepath, os/exec, etc).
 138         # OS includes string routines, but those must be layered above package os.
 139         # OS does not include reflection.
 140         io/fs
 141         < internal/testlog
 142         < internal/poll
 143         < os
 144         < os/signal;
 145
 146         io/fs
 147         < embed;
 148
 149         unicode, fmt !< net, os, os/signal;
 150
 151         os/signal, STR
 152         < path/filepath
 153         < io/ioutil;
 154
 155         os < internal/godebug;
 156
 157         path/filepath, internal/godebug < os/exec;
 158
 159         io/ioutil, os/exec, os/signal
 160         < OS;
 161
 162         reflect !< OS;
 163
 164         OS
 165         < golang.org/x/sys/cpu;
 166
 167         # FMT is OS (which includes string routines) plus reflect and fmt.
 168         # It does not include package log, which should be avoided in core packages.
 169         strconv, unicode
 170         < reflect;
 171
 172         os, reflect
 173         < internal/fmtsort
 174         < fmt;
 175
 176         OS, fmt
 177         < FMT;
 178
 179         log !< FMT;
 180
 181         # Misc packages needing only FMT.
 182         FMT
 183         < html,
 184           internal/dag,
 185           internal/goroot,
 186           mime/quotedprintable,
 187           net/internal/socktest,
 188           net/url,
 189           runtime/trace,
 190           text/scanner,
 191           text/tabwriter;
 192
 193         # encodings
 194         # core ones do not use fmt.
 195         io, strconv
 196         < encoding;
 197
 198         encoding, reflect
 199         < encoding/binary
 200         < encoding/base32, encoding/base64;
 201
 202         FMT, encoding < flag;
 203
 204         fmt !< encoding/base32, encoding/base64;
 205
 206         FMT, encoding/base32, encoding/base64
 207         < encoding/ascii85, encoding/csv, encoding/gob, encoding/hex,
 208           encoding/json, encoding/pem, encoding/xml, mime;
 209
 210         # hashes
 211         io
 212         < hash
 213         < hash/adler32, hash/crc32, hash/crc64, hash/fnv, hash/maphash;
 214
 215         # math/big
 216         FMT, encoding/binary, math/rand
 217         < math/big;
 218
 219         # compression
 220         FMT, encoding/binary, hash/adler32, hash/crc32
 221         < compress/bzip2, compress/flate, compress/lzw
 222         < archive/zip, compress/gzip, compress/zlib;
 223
 224         # templates
 225         FMT
 226         < text/template/parse;
 227
 228         net/url, text/template/parse
 229         < text/template
 230         < internal/lazytemplate;
 231
 232         encoding/json, html, text/template
 233         < html/template;
 234
 235         # regexp
 236         FMT
 237         < regexp/syntax
 238         < regexp
 239         < internal/lazyregexp;
 240
 241         # suffix array
 242         encoding/binary, regexp
 243         < index/suffixarray;
 244
 245         # executable parsing
 246         FMT, encoding/binary, compress/zlib, internal/saferio
 247         < runtime/debug
 248         < debug/dwarf
 249         < debug/elf, debug/gosym, debug/macho, debug/pe, debug/plan9obj, internal/xcoff
 250         < debug/buildinfo
 251         < DEBUG;
 252
 253         # go parser and friends.
 254         FMT
 255         < go/token
 256         < go/scanner
 257         < go/ast
 258         < go/internal/typeparams
 259         < go/parser;
 260
 261         FMT
 262         < go/build/constraint, go/doc/comment;
 263
 264         go/build/constraint, go/doc/comment, go/parser, text/tabwriter
 265         < go/printer
 266         < go/format;
 267
 268         go/doc/comment, go/parser, internal/lazyregexp, text/template
 269         < go/doc;
 270
 271         math/big, go/token
 272         < go/constant;
 273
 274         container/heap, go/constant, go/parser, regexp
 275         < go/types;
 276
 277         FMT, internal/goexperiment
 278         < internal/buildcfg;
 279
 280         go/build/constraint, go/doc, go/parser, internal/buildcfg, internal/goroot, internal/goversion
 281         < go/build;
 282
 283         # databases
 284         FMT
 285         < database/sql/internal
 286         < database/sql/driver
 287         < database/sql;
 288
 289         # images
 290         FMT, compress/lzw, compress/zlib
 291         < image/color
 292         < image, image/color/palette
 293         < image/internal/imageutil
 294         < image/draw
 295         < image/gif, image/jpeg, image/png;
 296
 297         # cgo, delayed as long as possible.
 298         # If you add a dependency on CGO, you must add the package
 299         # to cgoPackages in cmd/dist/test.go as well.
 300         RUNTIME
 301         < C
 302         < runtime/cgo
 303         < CGO
 304         < runtime/race, runtime/msan, runtime/asan;
 305
 306         # Bulk of the standard library must not use cgo.
 307         # The prohibition stops at net and os/user.
 308         C !< fmt, go/types, CRYPTO-MATH;
 309
 310         CGO, OS
 311         < plugin;
 312
 313         CGO, FMT
 314         < os/user
 315         < archive/tar;
 316
 317         sync
 318         < internal/singleflight;
 319
 320         os
 321         < golang.org/x/net/dns/dnsmessage,
 322           golang.org/x/net/lif,
 323           golang.org/x/net/route;
 324
 325         os, runtime, strconv, sync, unsafe,
 326         internal/godebug
 327         < internal/intern;
 328
 329         internal/bytealg, internal/intern, internal/itoa, math/bits, sort, strconv
 330         < net/netip;
 331
 332         # net is unavoidable when doing any networking,
 333         # so large dependencies must be kept out.
 334         # This is a long-looking list but most of these
 335         # are small with few dependencies.
 336         CGO,
 337         golang.org/x/net/dns/dnsmessage,
 338         golang.org/x/net/lif,
 339         golang.org/x/net/route,
 340         internal/godebug,
 341         internal/nettrace,
 342         internal/poll,
 343         internal/singleflight,
 344         internal/race,
 345         net/netip,
 346         os
 347         < net;
 348
 349         fmt, unicode !< net;
 350         math/rand !< net; # net uses runtime instead
 351
 352         # NET is net plus net-helper packages.
 353         FMT, net
 354         < net/textproto;
 355
 356         mime, net/textproto, net/url
 357         < NET;
 358
 359         # logging - most packages should not import; http and up is allowed
 360         FMT
 361         < log;
 362
 363         log !< crypto/tls, database/sql, go/importer, testing;
 364
 365         FMT, log, net
 366         < log/syslog;
 367
 368         NET, log
 369         < net/mail;
 370
 371         NONE < crypto/internal/boring/sig, crypto/internal/boring/syso;
 372         sync/atomic < crypto/internal/boring/bcache, crypto/internal/boring/fipstls;
 373         crypto/internal/boring/sig, crypto/internal/boring/fipstls < crypto/tls/fipsonly;
 374
 375         # CRYPTO is core crypto algorithms - no cgo, fmt, net.
 376         # Unfortunately, stuck with reflect via encoding/binary.
 377         crypto/internal/boring/sig,
 378         crypto/internal/boring/syso,
 379         encoding/binary,
 380         golang.org/x/sys/cpu,
 381         hash, embed
 382         < crypto
 383         < crypto/subtle
 384         < crypto/internal/subtle
 385         < crypto/internal/randutil
 386         < crypto/internal/nistec/fiat
 387         < crypto/internal/nistec
 388         < crypto/internal/edwards25519/field
 389         < crypto/internal/edwards25519, crypto/ecdh
 390         < crypto/cipher;
 391
 392         crypto/cipher,
 393         crypto/internal/boring/bcache
 394         < crypto/internal/boring
 395         < crypto/boring
 396         < crypto/aes, crypto/des, crypto/hmac, crypto/md5, crypto/rc4,
 397           crypto/sha1, crypto/sha256, crypto/sha512
 398         < CRYPTO;
 399
 400         CGO, fmt, net !< CRYPTO;
 401
 402         # CRYPTO-MATH is core bignum-based crypto - no cgo, net; fmt now ok.
 403         CRYPTO, FMT, math/big
 404         < crypto/internal/boring/bbig
 405         < crypto/rand
 406         < crypto/ed25519
 407         < encoding/asn1
 408         < golang.org/x/crypto/cryptobyte/asn1
 409         < golang.org/x/crypto/cryptobyte
 410         < crypto/dsa, crypto/elliptic, crypto/rsa
 411         < crypto/ecdsa
 412         < CRYPTO-MATH;
 413
 414         CGO, net !< CRYPTO-MATH;
 415
 416         # TLS, Prince of Dependencies.
 417         CRYPTO-MATH, NET, container/list, encoding/hex, encoding/pem
 418         < golang.org/x/crypto/internal/subtle
 419         < golang.org/x/crypto/chacha20
 420         < golang.org/x/crypto/internal/poly1305
 421         < golang.org/x/crypto/chacha20poly1305
 422         < golang.org/x/crypto/hkdf
 423         < crypto/x509/internal/macos
 424         < crypto/x509/pkix;
 425
 426         crypto/internal/boring/fipstls, crypto/x509/pkix
 427         < crypto/x509
 428         < crypto/tls;
 429
 430         # crypto-aware packages
 431
 432         DEBUG, go/build, go/types, text/scanner, crypto/md5
 433         < internal/pkgbits
 434         < go/internal/gcimporter, go/internal/gccgoimporter, go/internal/srcimporter
 435         < go/importer;
 436
 437         NET, crypto/rand, mime/quotedprintable
 438         < mime/multipart;
 439
 440         crypto/tls
 441         < net/smtp;
 442
 443         # HTTP, King of Dependencies.
 444
 445         FMT
 446         < golang.org/x/net/http2/hpack
 447         < net/http/internal, net/http/internal/ascii, net/http/internal/testcert;
 448
 449         FMT, NET, container/list, encoding/binary, log
 450         < golang.org/x/text/transform
 451         < golang.org/x/text/unicode/norm
 452         < golang.org/x/text/unicode/bidi
 453         < golang.org/x/text/secure/bidirule
 454         < golang.org/x/net/idna
 455         < golang.org/x/net/http/httpguts, golang.org/x/net/http/httpproxy;
 456
 457         NET, crypto/tls
 458         < net/http/httptrace;
 459
 460         compress/gzip,
 461         golang.org/x/net/http/httpguts,
 462         golang.org/x/net/http/httpproxy,
 463         golang.org/x/net/http2/hpack,
 464         net/http/internal,
 465         net/http/internal/ascii,
 466         net/http/internal/testcert,
 467         net/http/httptrace,
 468         mime/multipart,
 469         log
 470         < net/http;
 471
 472         # HTTP-aware packages
 473
 474         encoding/json, net/http
 475         < expvar;
 476
 477         net/http, net/http/internal/ascii
 478         < net/http/cookiejar, net/http/httputil;
 479
 480         net/http, flag
 481         < net/http/httptest;
 482
 483         net/http, regexp
 484         < net/http/cgi
 485         < net/http/fcgi;
 486
 487         # Profiling
 488         FMT, compress/gzip, encoding/binary, text/tabwriter
 489         < runtime/pprof;
 490
 491         OS, compress/gzip, regexp
 492         < internal/profile;
 493
 494         html, internal/profile, net/http, runtime/pprof, runtime/trace
 495         < net/http/pprof;
 496
 497         # RPC
 498         encoding/gob, encoding/json, go/token, html/template, net/http
 499         < net/rpc
 500         < net/rpc/jsonrpc;
 501
 502         # System Information
 503         internal/cpu, sync
 504         < internal/sysinfo;
 505
 506         # Test-only
 507         log
 508         < testing/iotest
 509         < testing/fstest;
 510
 511         FMT, flag, math/rand
 512         < testing/quick;
 513
 514         FMT, DEBUG, flag, runtime/trace, internal/sysinfo, math/rand
 515         < testing;
 516
 517         FMT, crypto/sha256, encoding/json, go/ast, go/parser, go/token,
 518         internal/godebug, math/rand, encoding/hex, crypto/sha256
 519         < internal/fuzz;
 520
 521         internal/fuzz, internal/testlog, runtime/pprof, regexp
 522         < testing/internal/testdeps;
 523
 524         OS, flag, testing, internal/cfg
 525         < internal/testenv;
 526
 527         OS, encoding/base64
 528         < internal/obscuretestdata;
 529
 530         CGO, OS, fmt
 531         < os/signal/internal/pty;
 532
 533         NET, testing, math/rand
 534         < golang.org/x/net/nettest;
 535
 536         syscall
 537         < os/exec/internal/fdtest;
 538
 539         FMT, container/heap, math/rand
 540         < internal/trace;
 541
 542         FMT
 543         < internal/diff, internal/txtar;
 544 `
 545
 546 // listStdPkgs returns the same list of packages as "go list std".
 547 func listStdPkgs(goroot string) ([]string, error) {
 548         // Based on cmd/go's matchPackages function.
 549         var pkgs []string
 550
 551         src := filepath.Join(goroot, "src") + string(filepath.Separator)
 552         walkFn := func(path string, d fs.DirEntry, err error) error {
 553                 if err != nil || !d.IsDir() || path == src {
 554                         return nil
 555                 }
 556
 557                 base := filepath.Base(path)
 558                 if strings.HasPrefix(base, ".") || strings.HasPrefix(base, "_") || base == "testdata" {
 559                         return filepath.SkipDir
 560                 }
 561
 562                 name := filepath.ToSlash(path[len(src):])
 563                 if name == "builtin" || name == "cmd" {
 564                         return filepath.SkipDir
 565                 }
 566
 567                 pkgs = append(pkgs, strings.TrimPrefix(name, "vendor/"))
 568                 return nil
 569         }
 570         if err := filepath.WalkDir(src, walkFn); err != nil {
 571                 return nil, err
 572         }
 573         return pkgs, nil
 574 }
 575
 576 func TestDependencies(t *testing.T) {
 577         if !testenv.HasSrc() {
 578                 // Tests run in a limited file system and we do not
 579                 // provide access to every source file.
 580                 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
 581         }
 582
 583         ctxt := Default
 584         all, err := listStdPkgs(ctxt.GOROOT)
 585         if err != nil {
 586                 t.Fatal(err)
 587         }
 588         sort.Strings(all)
 589
 590         sawImport := map[string]map[string]bool{} // from package => to package => true
 591         policy := depsPolicy(t)
 592
 593         for _, pkg := range all {
 594                 imports, err := findImports(pkg)
 595                 if err != nil {
 596                         t.Error(err)
 597                         continue
 598                 }
 599                 if sawImport[pkg] == nil {
 600                         sawImport[pkg] = map[string]bool{}
 601                 }
 602                 var bad []string
 603                 for _, imp := range imports {
 604                         sawImport[pkg][imp] = true
 605                         if !policy.HasEdge(pkg, imp) {
 606                                 bad = append(bad, imp)
 607                         }
 608                 }
 609                 if bad != nil {
 610                         t.Errorf("unexpected dependency: %s imports %v", pkg, bad)
 611                 }
 612         }
 613 }
 614
 615 var buildIgnore = []byte("\n//go:build ignore")
 616
 617 func findImports(pkg string) ([]string, error) {
 618         vpkg := pkg
 619         if strings.HasPrefix(pkg, "golang.org") {
 620                 vpkg = "vendor/" + pkg
 621         }
 622         dir := filepath.Join(Default.GOROOT, "src", vpkg)
 623         files, err := os.ReadDir(dir)
 624         if err != nil {
 625                 return nil, err
 626         }
 627         var imports []string
 628         var haveImport = map[string]bool{}
 629         if pkg == "crypto/internal/boring" {
 630                 haveImport["C"] = true // kludge: prevent C from appearing in crypto/internal/boring imports
 631         }
 632         fset := token.NewFileSet()
 633         for _, file := range files {
 634                 name := file.Name()
 635                 if name == "slice_go14.go" || name == "slice_go18.go" {
 636                         // These files are for compiler bootstrap with older versions of Go and not built in the standard build.
 637                         continue
 638                 }
 639                 if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
 640                         continue
 641                 }
 642                 info := fileInfo{
 643                         name: filepath.Join(dir, name),
 644                         fset: fset,
 645                 }
 646                 f, err := os.Open(info.name)
 647                 if err != nil {
 648                         return nil, err
 649                 }
 650                 err = readGoInfo(f, &info)
 651                 f.Close()
 652                 if err != nil {
 653                         return nil, fmt.Errorf("reading %v: %v", name, err)
 654                 }
 655                 if info.parsed.Name.Name == "main" {
 656                         continue
 657                 }
 658                 if bytes.Contains(info.header, buildIgnore) {
 659                         continue
 660                 }
 661                 for _, imp := range info.imports {
 662                         path := imp.path
 663                         if !haveImport[path] {
 664                                 haveImport[path] = true
 665                                 imports = append(imports, path)
 666                         }
 667                 }
 668         }
 669         sort.Strings(imports)
 670         return imports, nil
 671 }
 672
 673 // depsPolicy returns a map m such that m[p][d] == true when p can import d.
 674 func depsPolicy(t *testing.T) *dag.Graph {
 675         g, err := dag.Parse(depsRules)
 676         if err != nil {
 677                 t.Fatal(err)
 678         }
 679         return g
 680 }
 681
 682 // TestStdlibLowercase tests that all standard library package names are
 683 // lowercase. See Issue 40065.
 684 func TestStdlibLowercase(t *testing.T) {
 685         if !testenv.HasSrc() {
 686                 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
 687         }
 688
 689         ctxt := Default
 690         all, err := listStdPkgs(ctxt.GOROOT)
 691         if err != nil {
 692                 t.Fatal(err)
 693         }
 694
 695         for _, pkgname := range all {
 696                 if strings.ToLower(pkgname) != pkgname {
 697                         t.Errorf("package %q should not use upper-case path", pkgname)
 698                 }
 699         }
 700 }
 701
 702 // TestFindImports tests that findImports works.  See #43249.
 703 func TestFindImports(t *testing.T) {
 704         imports, err := findImports("go/build")
 705         if err != nil {
 706                 t.Fatal(err)
 707         }
 708         t.Logf("go/build imports %q", imports)
 709         want := []string{"bytes", "os", "path/filepath", "strings"}
 710 wantLoop:
 711         for _, w := range want {
 712                 for _, imp := range imports {
 713                         if imp == w {
 714                                 continue wantLoop
 715                         }
 716                 }
 717                 t.Errorf("expected to find %q in import list", w)
 718         }
 719 }