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         # STR is basic string and buffer manipulation.
 127         RUNTIME, io, unicode/utf8, unicode/utf16, unicode
 128         < bytes, strings
 129         < bufio;
 130
 131         bufio, path, strconv
 132         < STR;
 133
 134         # OS is basic OS access, including helpers (path/filepath, os/exec, etc).
 135         # OS includes string routines, but those must be layered above package os.
 136         # OS does not include reflection.
 137         io/fs
 138         < internal/testlog
 139         < internal/poll
 140         < os
 141         < os/signal;
 142
 143         io/fs
 144         < embed;
 145
 146         unicode, fmt !< net, os, os/signal;
 147
 148         os/signal, STR
 149         < path/filepath
 150         < io/ioutil;
 151
 152         os < internal/godebug;
 153
 154         path/filepath, internal/godebug < os/exec;
 155
 156         io/ioutil, os/exec, os/signal
 157         < OS;
 158
 159         reflect !< OS;
 160
 161         OS
 162         < golang.org/x/sys/cpu;
 163
 164         # FMT is OS (which includes string routines) plus reflect and fmt.
 165         # It does not include package log, which should be avoided in core packages.
 166         strconv, unicode
 167         < reflect;
 168
 169         os, reflect
 170         < internal/fmtsort
 171         < fmt;
 172
 173         OS, fmt
 174         < FMT;
 175
 176         log !< FMT;
 177
 178         # Misc packages needing only FMT.
 179         FMT
 180         < html,
 181           internal/dag,
 182           internal/goroot,
 183           mime/quotedprintable,
 184           net/internal/socktest,
 185           net/url,
 186           runtime/trace,
 187           text/scanner,
 188           text/tabwriter;
 189
 190         # encodings
 191         # core ones do not use fmt.
 192         io, strconv
 193         < encoding;
 194
 195         encoding, reflect
 196         < encoding/binary
 197         < encoding/base32, encoding/base64;
 198
 199         FMT, encoding < flag;
 200
 201         fmt !< encoding/base32, encoding/base64;
 202
 203         FMT, encoding/base32, encoding/base64
 204         < encoding/ascii85, encoding/csv, encoding/gob, encoding/hex,
 205           encoding/json, encoding/pem, encoding/xml, mime;
 206
 207         # hashes
 208         io
 209         < hash
 210         < hash/adler32, hash/crc32, hash/crc64, hash/fnv, hash/maphash;
 211
 212         # math/big
 213         FMT, encoding/binary, math/rand
 214         < math/big;
 215
 216         # compression
 217         FMT, encoding/binary, hash/adler32, hash/crc32
 218         < compress/bzip2, compress/flate, compress/lzw
 219         < archive/zip, compress/gzip, compress/zlib;
 220
 221         # templates
 222         FMT
 223         < text/template/parse;
 224
 225         net/url, text/template/parse
 226         < text/template
 227         < internal/lazytemplate;
 228
 229         encoding/json, html, text/template
 230         < html/template;
 231
 232         # regexp
 233         FMT
 234         < regexp/syntax
 235         < regexp
 236         < internal/lazyregexp;
 237
 238         # suffix array
 239         encoding/binary, regexp
 240         < index/suffixarray;
 241
 242         # executable parsing
 243         FMT, encoding/binary, compress/zlib
 244         < runtime/debug
 245         < debug/dwarf
 246         < debug/elf, debug/gosym, debug/macho, debug/pe, debug/plan9obj, internal/xcoff
 247         < debug/buildinfo
 248         < DEBUG;
 249
 250         # go parser and friends.
 251         FMT
 252         < go/token
 253         < go/scanner
 254         < go/ast
 255         < go/internal/typeparams
 256         < go/parser;
 257
 258         FMT
 259         < go/build/constraint, go/doc/comment;
 260
 261         go/build/constraint, go/doc/comment, go/parser, text/tabwriter
 262         < go/printer
 263         < go/format;
 264
 265         go/doc/comment, go/parser, internal/lazyregexp, text/template
 266         < go/doc;
 267
 268         math/big, go/token
 269         < go/constant;
 270
 271         container/heap, go/constant, go/parser, regexp
 272         < go/types;
 273
 274         FMT, internal/goexperiment
 275         < internal/buildcfg;
 276
 277         go/build/constraint, go/doc, go/parser, internal/buildcfg, internal/goroot, internal/goversion
 278         < go/build;
 279
 280         # databases
 281         FMT
 282         < database/sql/internal
 283         < database/sql/driver
 284         < database/sql;
 285
 286         # images
 287         FMT, compress/lzw, compress/zlib
 288         < image/color
 289         < image, image/color/palette
 290         < image/internal/imageutil
 291         < image/draw
 292         < image/gif, image/jpeg, image/png;
 293
 294         # cgo, delayed as long as possible.
 295         # If you add a dependency on CGO, you must add the package
 296         # to cgoPackages in cmd/dist/test.go as well.
 297         RUNTIME
 298         < C
 299         < runtime/cgo
 300         < CGO
 301         < runtime/race, runtime/msan, runtime/asan;
 302
 303         # Bulk of the standard library must not use cgo.
 304         # The prohibition stops at net and os/user.
 305         C !< fmt, go/types, CRYPTO-MATH;
 306
 307         CGO, OS
 308         < plugin;
 309
 310         CGO, FMT
 311         < os/user
 312         < archive/tar;
 313
 314         sync
 315         < internal/singleflight;
 316
 317         os
 318         < golang.org/x/net/dns/dnsmessage,
 319           golang.org/x/net/lif,
 320           golang.org/x/net/route;
 321
 322         os, runtime, strconv, sync, unsafe,
 323         internal/godebug
 324         < internal/intern;
 325
 326         internal/bytealg, internal/intern, internal/itoa, math/bits, sort, strconv
 327         < net/netip;
 328
 329         # net is unavoidable when doing any networking,
 330         # so large dependencies must be kept out.
 331         # This is a long-looking list but most of these
 332         # are small with few dependencies.
 333         CGO,
 334         golang.org/x/net/dns/dnsmessage,
 335         golang.org/x/net/lif,
 336         golang.org/x/net/route,
 337         internal/godebug,
 338         internal/nettrace,
 339         internal/poll,
 340         internal/singleflight,
 341         internal/race,
 342         net/netip,
 343         os
 344         < net;
 345
 346         fmt, unicode !< net;
 347         math/rand !< net; # net uses runtime instead
 348
 349         # NET is net plus net-helper packages.
 350         FMT, net
 351         < net/textproto;
 352
 353         mime, net/textproto, net/url
 354         < NET;
 355
 356         # logging - most packages should not import; http and up is allowed
 357         FMT
 358         < log;
 359
 360         log !< crypto/tls, database/sql, go/importer, testing;
 361
 362         FMT, log, net
 363         < log/syslog;
 364
 365         NET, log
 366         < net/mail;
 367
 368         NONE < crypto/internal/boring/sig, crypto/internal/boring/syso;
 369         sync/atomic < crypto/internal/boring/bcache, crypto/internal/boring/fipstls;
 370         crypto/internal/boring/sig, crypto/internal/boring/fipstls < crypto/tls/fipsonly;
 371
 372         # CRYPTO is core crypto algorithms - no cgo, fmt, net.
 373         # Unfortunately, stuck with reflect via encoding/binary.
 374         crypto/internal/boring/sig,
 375         crypto/internal/boring/syso,
 376         encoding/binary,
 377         golang.org/x/sys/cpu,
 378         hash, embed
 379         < crypto
 380         < crypto/subtle
 381         < crypto/internal/subtle
 382         < crypto/internal/nistec/fiat
 383         < crypto/internal/nistec
 384         < crypto/internal/edwards25519/field, golang.org/x/crypto/curve25519/internal/field
 385         < crypto/internal/edwards25519
 386         < crypto/cipher;
 387
 388         crypto/cipher,
 389         crypto/internal/boring/bcache
 390         < crypto/internal/boring
 391         < crypto/boring
 392         < crypto/aes, crypto/des, crypto/hmac, crypto/md5, crypto/rc4,
 393           crypto/sha1, crypto/sha256, crypto/sha512
 394         < CRYPTO;
 395
 396         CGO, fmt, net !< CRYPTO;
 397
 398         # CRYPTO-MATH is core bignum-based crypto - no cgo, net; fmt now ok.
 399         CRYPTO, FMT, math/big, embed
 400         < crypto/internal/boring/bbig
 401         < crypto/internal/randutil
 402         < crypto/rand
 403         < crypto/ed25519
 404         < encoding/asn1
 405         < golang.org/x/crypto/cryptobyte/asn1
 406         < golang.org/x/crypto/cryptobyte
 407         < golang.org/x/crypto/curve25519
 408         < crypto/dsa, crypto/elliptic, crypto/rsa
 409         < crypto/ecdsa
 410         < CRYPTO-MATH;
 411
 412         CGO, net !< CRYPTO-MATH;
 413
 414         # TLS, Prince of Dependencies.
 415         CRYPTO-MATH, NET, container/list, encoding/hex, encoding/pem
 416         < golang.org/x/crypto/internal/subtle
 417         < golang.org/x/crypto/chacha20
 418         < golang.org/x/crypto/internal/poly1305
 419         < golang.org/x/crypto/chacha20poly1305
 420         < golang.org/x/crypto/hkdf
 421         < crypto/x509/internal/macos
 422         < crypto/x509/pkix;
 423
 424         crypto/internal/boring/fipstls, crypto/x509/pkix
 425         < crypto/x509
 426         < crypto/tls;
 427
 428         # crypto-aware packages
 429
 430         DEBUG, go/build, go/types, text/scanner, crypto/md5
 431         < internal/pkgbits
 432         < go/internal/gcimporter, go/internal/gccgoimporter, go/internal/srcimporter
 433         < go/importer;
 434
 435         NET, crypto/rand, mime/quotedprintable
 436         < mime/multipart;
 437
 438         crypto/tls
 439         < net/smtp;
 440
 441         # HTTP, King of Dependencies.
 442
 443         FMT
 444         < golang.org/x/net/http2/hpack
 445         < net/http/internal, net/http/internal/ascii, net/http/internal/testcert;
 446
 447         FMT, NET, container/list, encoding/binary, log
 448         < golang.org/x/text/transform
 449         < golang.org/x/text/unicode/norm
 450         < golang.org/x/text/unicode/bidi
 451         < golang.org/x/text/secure/bidirule
 452         < golang.org/x/net/idna
 453         < golang.org/x/net/http/httpguts, golang.org/x/net/http/httpproxy;
 454
 455         NET, crypto/tls
 456         < net/http/httptrace;
 457
 458         compress/gzip,
 459         golang.org/x/net/http/httpguts,
 460         golang.org/x/net/http/httpproxy,
 461         golang.org/x/net/http2/hpack,
 462         net/http/internal,
 463         net/http/internal/ascii,
 464         net/http/internal/testcert,
 465         net/http/httptrace,
 466         mime/multipart,
 467         log
 468         < net/http;
 469
 470         # HTTP-aware packages
 471
 472         encoding/json, net/http
 473         < expvar;
 474
 475         net/http, net/http/internal/ascii
 476         < net/http/cookiejar, net/http/httputil;
 477
 478         net/http, flag
 479         < net/http/httptest;
 480
 481         net/http, regexp
 482         < net/http/cgi
 483         < net/http/fcgi;
 484
 485         # Profiling
 486         FMT, compress/gzip, encoding/binary, text/tabwriter
 487         < runtime/pprof;
 488
 489         OS, compress/gzip, regexp
 490         < internal/profile;
 491
 492         html, internal/profile, net/http, runtime/pprof, runtime/trace
 493         < net/http/pprof;
 494
 495         # RPC
 496         encoding/gob, encoding/json, go/token, html/template, net/http
 497         < net/rpc
 498         < net/rpc/jsonrpc;
 499
 500         # System Information
 501         internal/cpu, sync
 502         < internal/sysinfo;
 503
 504         # Test-only
 505         log
 506         < testing/iotest
 507         < testing/fstest;
 508
 509         FMT, flag, math/rand
 510         < testing/quick;
 511
 512         FMT, DEBUG, flag, runtime/trace, internal/sysinfo, math/rand
 513         < testing;
 514
 515         FMT, crypto/sha256, encoding/json, go/ast, go/parser, go/token,
 516         internal/godebug, math/rand, encoding/hex, crypto/sha256
 517         < internal/fuzz;
 518
 519         internal/fuzz, internal/testlog, runtime/pprof, regexp
 520         < testing/internal/testdeps;
 521
 522         OS, flag, testing, internal/cfg
 523         < internal/testenv;
 524
 525         OS, encoding/base64
 526         < internal/obscuretestdata;
 527
 528         CGO, OS, fmt
 529         < os/signal/internal/pty;
 530
 531         NET, testing, math/rand
 532         < golang.org/x/net/nettest;
 533
 534         syscall
 535         < os/exec/internal/fdtest;
 536
 537         FMT, container/heap, math/rand
 538         < internal/trace;
 539
 540         FMT
 541         < internal/diff, internal/txtar;
 542 `
 543
 544 // listStdPkgs returns the same list of packages as "go list std".
 545 func listStdPkgs(goroot string) ([]string, error) {
 546         // Based on cmd/go's matchPackages function.
 547         var pkgs []string
 548
 549         src := filepath.Join(goroot, "src") + string(filepath.Separator)
 550         walkFn := func(path string, d fs.DirEntry, err error) error {
 551                 if err != nil || !d.IsDir() || path == src {
 552                         return nil
 553                 }
 554
 555                 base := filepath.Base(path)
 556                 if strings.HasPrefix(base, ".") || strings.HasPrefix(base, "_") || base == "testdata" {
 557                         return filepath.SkipDir
 558                 }
 559
 560                 name := filepath.ToSlash(path[len(src):])
 561                 if name == "builtin" || name == "cmd" {
 562                         return filepath.SkipDir
 563                 }
 564
 565                 pkgs = append(pkgs, strings.TrimPrefix(name, "vendor/"))
 566                 return nil
 567         }
 568         if err := filepath.WalkDir(src, walkFn); err != nil {
 569                 return nil, err
 570         }
 571         return pkgs, nil
 572 }
 573
 574 func TestDependencies(t *testing.T) {
 575         if !testenv.HasSrc() {
 576                 // Tests run in a limited file system and we do not
 577                 // provide access to every source file.
 578                 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
 579         }
 580
 581         ctxt := Default
 582         all, err := listStdPkgs(ctxt.GOROOT)
 583         if err != nil {
 584                 t.Fatal(err)
 585         }
 586         sort.Strings(all)
 587
 588         sawImport := map[string]map[string]bool{} // from package => to package => true
 589         policy := depsPolicy(t)
 590
 591         for _, pkg := range all {
 592                 imports, err := findImports(pkg)
 593                 if err != nil {
 594                         t.Error(err)
 595                         continue
 596                 }
 597                 if sawImport[pkg] == nil {
 598                         sawImport[pkg] = map[string]bool{}
 599                 }
 600                 var bad []string
 601                 for _, imp := range imports {
 602                         sawImport[pkg][imp] = true
 603                         if !policy.HasEdge(pkg, imp) {
 604                                 bad = append(bad, imp)
 605                         }
 606                 }
 607                 if bad != nil {
 608                         t.Errorf("unexpected dependency: %s imports %v", pkg, bad)
 609                 }
 610         }
 611 }
 612
 613 var buildIgnore = []byte("\n//go:build ignore")
 614
 615 func findImports(pkg string) ([]string, error) {
 616         vpkg := pkg
 617         if strings.HasPrefix(pkg, "golang.org") {
 618                 vpkg = "vendor/" + pkg
 619         }
 620         dir := filepath.Join(Default.GOROOT, "src", vpkg)
 621         files, err := os.ReadDir(dir)
 622         if err != nil {
 623                 return nil, err
 624         }
 625         var imports []string
 626         var haveImport = map[string]bool{}
 627         if pkg == "crypto/internal/boring" {
 628                 haveImport["C"] = true // kludge: prevent C from appearing in crypto/internal/boring imports
 629         }
 630         fset := token.NewFileSet()
 631         for _, file := range files {
 632                 name := file.Name()
 633                 if name == "slice_go14.go" || name == "slice_go18.go" {
 634                         // These files are for compiler bootstrap with older versions of Go and not built in the standard build.
 635                         continue
 636                 }
 637                 if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
 638                         continue
 639                 }
 640                 info := fileInfo{
 641                         name: filepath.Join(dir, name),
 642                         fset: fset,
 643                 }
 644                 f, err := os.Open(info.name)
 645                 if err != nil {
 646                         return nil, err
 647                 }
 648                 err = readGoInfo(f, &info)
 649                 f.Close()
 650                 if err != nil {
 651                         return nil, fmt.Errorf("reading %v: %v", name, err)
 652                 }
 653                 if info.parsed.Name.Name == "main" {
 654                         continue
 655                 }
 656                 if bytes.Contains(info.header, buildIgnore) {
 657                         continue
 658                 }
 659                 for _, imp := range info.imports {
 660                         path := imp.path
 661                         if !haveImport[path] {
 662                                 haveImport[path] = true
 663                                 imports = append(imports, path)
 664                         }
 665                 }
 666         }
 667         sort.Strings(imports)
 668         return imports, nil
 669 }
 670
 671 // depsPolicy returns a map m such that m[p][d] == true when p can import d.
 672 func depsPolicy(t *testing.T) *dag.Graph {
 673         g, err := dag.Parse(depsRules)
 674         if err != nil {
 675                 t.Fatal(err)
 676         }
 677         return g
 678 }
 679
 680 // TestStdlibLowercase tests that all standard library package names are
 681 // lowercase. See Issue 40065.
 682 func TestStdlibLowercase(t *testing.T) {
 683         if !testenv.HasSrc() {
 684                 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
 685         }
 686
 687         ctxt := Default
 688         all, err := listStdPkgs(ctxt.GOROOT)
 689         if err != nil {
 690                 t.Fatal(err)
 691         }
 692
 693         for _, pkgname := range all {
 694                 if strings.ToLower(pkgname) != pkgname {
 695                         t.Errorf("package %q should not use upper-case path", pkgname)
 696                 }
 697         }
 698 }
 699
 700 // TestFindImports tests that findImports works.  See #43249.
 701 func TestFindImports(t *testing.T) {
 702         imports, err := findImports("go/build")
 703         if err != nil {
 704                 t.Fatal(err)
 705         }
 706         t.Logf("go/build imports %q", imports)
 707         want := []string{"bytes", "os", "path/filepath", "strings"}
 708 wantLoop:
 709         for _, w := range want {
 710                 for _, imp := range imports {
 711                         if imp == w {
 712                                 continue wantLoop
 713                         }
 714                 }
 715                 t.Errorf("expected to find %q in import list", w)
 716         }
 717 }