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.
5 // This file exercises the import parser but also checks that
6 // some low-level packages do not have new dependencies added.
25 // depsRules defines the expected dependencies between packages in
26 // the Go source tree. It is a statement of policy.
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.
33 // "a < b" means package b can import package a.
35 // See `go doc internal/dag' for the full syntax.
37 // All-caps names are pseudo-names for specific points
38 // in the dependency lattice.
40 # No dependencies allowed for any of these packages.
42 < cmp, container/list, container/ring,
43 internal/cfg, internal/coverage, internal/coverage/rtcov,
44 internal/coverage/uleb128, internal/coverage/calloc,
45 internal/cpu, internal/goarch, internal/godebugs,
46 internal/goexperiment, internal/goos,
47 internal/goversion, internal/nettrace, internal/platform,
49 unicode/utf8, unicode/utf16, unicode,
52 # These packages depend only on internal/goarch and unsafe.
53 internal/goarch, unsafe
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/godebugs, internal/goexperiment,
64 < internal/unsafeheader
65 < runtime/internal/sys
66 < runtime/internal/syscall
67 < runtime/internal/atomic
68 < runtime/internal/math
75 < internal/reflectlite
77 < internal/oserror, math/bits
80 # slices depends on unsafe for overlapping check, cmp for comparison
81 # semantics, and math/bits for # calculating bitlength of numbers.
82 unsafe, cmp, math/bits
100 RUNTIME, unicode/utf8
105 # SYSCALL is RUNTIME plus the packages necessary for basic system calls.
106 RUNTIME, unicode/utf8, unicode/utf16
107 < internal/syscall/windows/sysdll, syscall/js
109 < internal/syscall/unix, internal/syscall/windows, internal/syscall/windows/registry
110 < internal/syscall/execenv
113 # TIME is SYSCALL plus the core packages about time, including context.
123 # MATH is RUNTIME plus the basic math packages.
134 < math/rand, math/rand/v2;
144 # STR is basic string and buffer manipulation.
145 RUNTIME, io, unicode/utf8, unicode/utf16, unicode
152 # OS is basic OS access, including helpers (path/filepath, os/exec, etc).
153 # OS includes string routines, but those must be layered above package os.
154 # OS does not include reflection.
158 < internal/safefilepath
165 unicode, fmt !< net, os, os/signal;
167 os/signal, internal/safefilepath, STR
171 path/filepath, internal/godebug < os/exec;
173 io/ioutil, os/exec, os/signal
179 < golang.org/x/sys/cpu;
181 # FMT is OS (which includes string routines) plus reflect and fmt.
182 # It does not include package log, which should be avoided in core packages.
183 arena, strconv, unicode
195 # Misc packages needing only FMT.
200 internal/types/errors,
201 mime/quotedprintable,
202 net/internal/socktest,
212 # core ones do not use fmt.
218 < encoding/base32, encoding/base64;
220 FMT, encoding < flag;
222 fmt !< encoding/base32, encoding/base64;
224 FMT, encoding/base32, encoding/base64, internal/saferio
225 < encoding/ascii85, encoding/csv, encoding/gob, encoding/hex,
226 encoding/json, encoding/pem, encoding/xml, mime;
231 < hash/adler32, hash/crc32, hash/crc64, hash/fnv;
234 FMT, encoding/binary, math/rand
238 FMT, encoding/binary, hash/adler32, hash/crc32
239 < compress/bzip2, compress/flate, compress/lzw, internal/zstd
240 < archive/zip, compress/gzip, compress/zlib;
244 < text/template/parse;
246 net/url, text/template/parse
248 < internal/lazytemplate;
254 < internal/lazyregexp;
256 encoding/json, html, text/template, regexp
260 encoding/binary, regexp
264 FMT, encoding/binary, compress/zlib, internal/saferio, internal/zstd
267 < debug/elf, debug/gosym, debug/macho, debug/pe, debug/plan9obj, internal/xcoff
271 # go parser and friends.
278 < go/internal/typeparams;
281 < go/build/constraint, go/doc/comment;
283 go/internal/typeparams, go/build/constraint
286 go/doc/comment, go/parser, text/tabwriter
293 FMT, internal/goexperiment
296 container/heap, go/constant, go/parser, internal/buildcfg, internal/goversion, internal/types/errors
299 # The vast majority of standard library packages should not be resorting to regexp.
300 # go/types is a good chokepoint. It shouldn't use regexp, nor should anything
301 # that is low-enough level to be used by go/types.
304 go/doc/comment, go/parser, internal/lazyregexp, text/template
307 go/build/constraint, go/doc, go/parser, internal/buildcfg, internal/goroot, internal/goversion, internal/platform
312 < database/sql/internal
313 < database/sql/driver
317 FMT, compress/lzw, compress/zlib
319 < image, image/color/palette
320 < image/internal/imageutil
322 < image/gif, image/jpeg, image/png;
324 # cgo, delayed as long as possible.
325 # If you add a dependency on CGO, you must add the package
326 # to cgoPackages in cmd/dist/test.go as well.
331 < runtime/msan, runtime/asan;
334 NONE < runtime/race/internal/amd64v1;
335 NONE < runtime/race/internal/amd64v3;
336 CGO, runtime/race/internal/amd64v1, runtime/race/internal/amd64v3 < runtime/race;
338 # Bulk of the standard library must not use cgo.
339 # The prohibition stops at net and os/user.
340 C !< fmt, go/types, CRYPTO-MATH, log/slog;
350 < internal/singleflight;
353 < golang.org/x/net/dns/dnsmessage,
354 golang.org/x/net/lif,
355 golang.org/x/net/route;
357 os, runtime, strconv, sync, unsafe,
361 internal/bytealg, internal/intern, internal/itoa, math/bits, sort, strconv
364 # net is unavoidable when doing any networking,
365 # so large dependencies must be kept out.
366 # This is a long-looking list but most of these
367 # are small with few dependencies.
369 golang.org/x/net/dns/dnsmessage,
370 golang.org/x/net/lif,
371 golang.org/x/net/route,
375 internal/singleflight,
382 math/rand !< net; # net uses runtime instead
384 # NET is net plus net-helper packages.
388 mime, net/textproto, net/url
391 # logging - most packages should not import; http and up is allowed
395 log, log/slog !< crypto/tls, database/sql, go/importer, testing;
401 < log/slog/internal, log/slog/internal/buffer;
404 encoding, encoding/json,
406 log/slog/internal, log/slog/internal/buffer,
409 < log/slog/internal/slogtest, log/slog/internal/benchmarks;
414 NONE < crypto/internal/boring/sig, crypto/internal/boring/syso;
415 sync/atomic < crypto/internal/boring/bcache, crypto/internal/boring/fipstls;
416 crypto/internal/boring/sig, crypto/internal/boring/fipstls < crypto/tls/fipsonly;
418 # CRYPTO is core crypto algorithms - no cgo, fmt, net.
419 # Unfortunately, stuck with reflect via encoding/binary.
420 crypto/internal/boring/sig,
421 crypto/internal/boring/syso,
423 golang.org/x/sys/cpu,
427 < crypto/internal/alias
431 crypto/internal/boring/bcache
432 < crypto/internal/boring
435 crypto/internal/alias
436 < crypto/internal/randutil
437 < crypto/internal/nistec/fiat
438 < crypto/internal/nistec
439 < crypto/internal/edwards25519/field
440 < crypto/internal/edwards25519;
443 < crypto/aes, crypto/des, crypto/hmac, crypto/md5, crypto/rc4,
444 crypto/sha1, crypto/sha256, crypto/sha512;
446 crypto/boring, crypto/internal/edwards25519/field
453 crypto/internal/edwards25519,
461 CGO, fmt, net !< CRYPTO;
463 # CRYPTO-MATH is core bignum-based crypto - no cgo, net; fmt now ok.
464 CRYPTO, FMT, math/big
465 < crypto/internal/boring/bbig
469 < golang.org/x/crypto/cryptobyte/asn1
470 < golang.org/x/crypto/cryptobyte
471 < crypto/internal/bigmod
472 < crypto/dsa, crypto/elliptic, crypto/rsa
476 CGO, net !< CRYPTO-MATH;
478 # TLS, Prince of Dependencies.
479 CRYPTO-MATH, NET, container/list, encoding/hex, encoding/pem
480 < golang.org/x/crypto/internal/alias
481 < golang.org/x/crypto/internal/subtle
482 < golang.org/x/crypto/chacha20
483 < golang.org/x/crypto/internal/poly1305
484 < golang.org/x/crypto/chacha20poly1305
485 < golang.org/x/crypto/hkdf
486 < crypto/x509/internal/macos
489 crypto/internal/boring/fipstls, crypto/x509/pkix
493 # crypto-aware packages
495 DEBUG, go/build, go/types, text/scanner, crypto/md5
497 < go/internal/gcimporter, go/internal/gccgoimporter, go/internal/srcimporter
500 NET, crypto/rand, mime/quotedprintable
507 < hash/maphash; # for purego implementation
509 # HTTP, King of Dependencies.
512 < golang.org/x/net/http2/hpack
513 < net/http/internal, net/http/internal/ascii, net/http/internal/testcert;
515 FMT, NET, container/list, encoding/binary, log
516 < golang.org/x/text/transform
517 < golang.org/x/text/unicode/norm
518 < golang.org/x/text/unicode/bidi
519 < golang.org/x/text/secure/bidirule
520 < golang.org/x/net/idna
521 < golang.org/x/net/http/httpguts, golang.org/x/net/http/httpproxy;
524 < net/http/httptrace;
527 golang.org/x/net/http/httpguts,
528 golang.org/x/net/http/httpproxy,
529 golang.org/x/net/http2/hpack,
531 net/http/internal/ascii,
532 net/http/internal/testcert,
538 # HTTP-aware packages
540 encoding/json, net/http
543 net/http, net/http/internal/ascii
544 < net/http/cookiejar, net/http/httputil;
554 FMT, compress/gzip, encoding/binary, text/tabwriter
557 OS, compress/gzip, internal/lazyregexp
560 html, internal/profile, net/http, runtime/pprof, runtime/trace
564 encoding/gob, encoding/json, go/token, html/template, net/http
569 bufio, bytes, internal/cpu, io, os, strings, sync
580 FMT, DEBUG, flag, runtime/trace, internal/sysinfo, math/rand
586 FMT, crypto/sha256, encoding/json, go/ast, go/parser, go/token,
587 internal/godebug, math/rand, encoding/hex, crypto/sha256
590 internal/fuzz, internal/testlog, runtime/pprof, regexp
591 < testing/internal/testdeps;
593 OS, flag, testing, internal/cfg, internal/platform, internal/goroot
597 < internal/obscuretestdata;
602 NET, testing, math/rand
603 < golang.org/x/net/nettest;
606 < os/exec/internal/fdtest;
609 < internal/diff, internal/txtar;
611 FMT, container/heap, math/rand
614 # v2 execution trace parser.
616 < internal/trace/v2/event;
618 internal/trace/v2/event
619 < internal/trace/v2/event/go122;
621 FMT, io, internal/trace/v2/event/go122
622 < internal/trace/v2/version;
624 FMT, encoding/binary, internal/trace/v2/version
625 < internal/trace/v2/raw;
627 FMT, encoding/binary, internal/trace/v2/version
630 regexp, internal/trace/v2, internal/trace/v2/raw, internal/txtar
631 < internal/trace/v2/testtrace;
633 regexp, internal/txtar, internal/trace/v2, internal/trace/v2/raw
634 < internal/trace/v2/internal/testgen/go122;
637 FMT, crypto/md5, encoding/binary, regexp, sort, text/tabwriter, unsafe,
638 internal/coverage, internal/coverage/uleb128
639 < internal/coverage/cmerge,
640 internal/coverage/pods,
641 internal/coverage/slicereader,
642 internal/coverage/slicewriter;
644 internal/coverage/slicereader, internal/coverage/slicewriter
645 < internal/coverage/stringtab
646 < internal/coverage/decodecounter, internal/coverage/decodemeta,
647 internal/coverage/encodecounter, internal/coverage/encodemeta;
649 internal/coverage/cmerge
650 < internal/coverage/cformat;
652 internal/coverage, crypto/sha256, FMT
653 < cmd/internal/cov/covcmd;
657 internal/coverage/calloc,
658 internal/coverage/cformat,
659 internal/coverage/decodecounter, internal/coverage/decodemeta,
660 internal/coverage/encodecounter, internal/coverage/encodemeta,
661 internal/coverage/pods
665 // listStdPkgs returns the same list of packages as "go list std".
666 func listStdPkgs(goroot string) ([]string, error) {
667 // Based on cmd/go's matchPackages function.
670 src := filepath.Join(goroot, "src") + string(filepath.Separator)
671 walkFn := func(path string, d fs.DirEntry, err error) error {
672 if err != nil || !d.IsDir() || path == src {
676 base := filepath.Base(path)
677 if strings.HasPrefix(base, ".") || strings.HasPrefix(base, "_") || base == "testdata" {
678 return filepath.SkipDir
681 name := filepath.ToSlash(path[len(src):])
682 if name == "builtin" || name == "cmd" {
683 return filepath.SkipDir
686 pkgs = append(pkgs, strings.TrimPrefix(name, "vendor/"))
689 if err := filepath.WalkDir(src, walkFn); err != nil {
695 func TestDependencies(t *testing.T) {
696 if !testenv.HasSrc() {
697 // Tests run in a limited file system and we do not
698 // provide access to every source file.
699 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
703 all, err := listStdPkgs(ctxt.GOROOT)
709 sawImport := map[string]map[string]bool{} // from package => to package => true
710 policy := depsPolicy(t)
712 for _, pkg := range all {
713 imports, err := findImports(pkg)
718 if sawImport[pkg] == nil {
719 sawImport[pkg] = map[string]bool{}
722 for _, imp := range imports {
723 sawImport[pkg][imp] = true
724 if !policy.HasEdge(pkg, imp) {
725 bad = append(bad, imp)
729 t.Errorf("unexpected dependency: %s imports %v", pkg, bad)
734 var buildIgnore = []byte("\n//go:build ignore")
736 func findImports(pkg string) ([]string, error) {
738 if strings.HasPrefix(pkg, "golang.org") {
739 vpkg = "vendor/" + pkg
741 dir := filepath.Join(Default.GOROOT, "src", vpkg)
742 files, err := os.ReadDir(dir)
747 var haveImport = map[string]bool{}
748 if pkg == "crypto/internal/boring" {
749 haveImport["C"] = true // kludge: prevent C from appearing in crypto/internal/boring imports
751 fset := token.NewFileSet()
752 for _, file := range files {
754 if name == "slice_go14.go" || name == "slice_go18.go" {
755 // These files are for compiler bootstrap with older versions of Go and not built in the standard build.
758 if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
762 name: filepath.Join(dir, name),
765 f, err := os.Open(info.name)
769 err = readGoInfo(f, &info)
772 return nil, fmt.Errorf("reading %v: %v", name, err)
774 if info.parsed.Name.Name == "main" {
777 if bytes.Contains(info.header, buildIgnore) {
780 for _, imp := range info.imports {
782 if !haveImport[path] {
783 haveImport[path] = true
784 imports = append(imports, path)
788 sort.Strings(imports)
792 // depsPolicy returns a map m such that m[p][d] == true when p can import d.
793 func depsPolicy(t *testing.T) *dag.Graph {
794 g, err := dag.Parse(depsRules)
801 // TestStdlibLowercase tests that all standard library package names are
802 // lowercase. See Issue 40065.
803 func TestStdlibLowercase(t *testing.T) {
804 if !testenv.HasSrc() {
805 t.Skipf("skipping on %s/%s, missing full GOROOT", runtime.GOOS, runtime.GOARCH)
809 all, err := listStdPkgs(ctxt.GOROOT)
814 for _, pkgname := range all {
815 if strings.ToLower(pkgname) != pkgname {
816 t.Errorf("package %q should not use upper-case path", pkgname)
821 // TestFindImports tests that findImports works. See #43249.
822 func TestFindImports(t *testing.T) {
823 imports, err := findImports("go/build")
827 t.Logf("go/build imports %q", imports)
828 want := []string{"bytes", "os", "path/filepath", "strings"}
830 for _, w := range want {
831 for _, imp := range imports {
836 t.Errorf("expected to find %q in import list", w)