1 // Copyright 2015 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 package shared_test 6 7 import ( 8 "bufio" 9 "bytes" 10 "debug/elf" 11 "encoding/binary" 12 "errors" 13 "flag" 14 "fmt" 15 "go/build" 16 "io" 17 "io/ioutil" 18 "log" 19 "math/rand" 20 "os" 21 "os/exec" 22 "path/filepath" 23 "regexp" 24 "runtime" 25 "strings" 26 "testing" 27 "time" 28 ) 29 30 var gopathInstallDir, gorootInstallDir, suffix string 31 32 // This is the smallest set of packages we can link into a shared 33 // library (runtime/cgo is built implicitly). 34 var minpkgs = []string{"runtime", "sync/atomic"} 35 var soname = "libruntime,sync-atomic.so" 36 37 // run runs a command and calls t.Errorf if it fails. 38 func run(t *testing.T, msg string, args ...string) { 39 c := exec.Command(args[0], args[1:]...) 40 if output, err := c.CombinedOutput(); err != nil { 41 t.Errorf("executing %s (%s) failed %s:\n%s", strings.Join(args, " "), msg, err, output) 42 } 43 } 44 45 // goCmd invokes the go tool with the installsuffix set up by TestMain. It calls 46 // t.Fatalf if the command fails. 47 func goCmd(t *testing.T, args ...string) { 48 newargs := []string{args[0], "-installsuffix=" + suffix} 49 if testing.Verbose() { 50 newargs = append(newargs, "-v") 51 } 52 newargs = append(newargs, args[1:]...) 53 c := exec.Command("go", newargs...) 54 var output []byte 55 var err error 56 if testing.Verbose() { 57 fmt.Printf("+ go %s\n", strings.Join(newargs, " ")) 58 c.Stdout = os.Stdout 59 c.Stderr = os.Stderr 60 err = c.Run() 61 } else { 62 output, err = c.CombinedOutput() 63 } 64 if err != nil { 65 if t != nil { 66 t.Fatalf("executing %s failed %v:\n%s", strings.Join(c.Args, " "), err, output) 67 } else { 68 log.Fatalf("executing %s failed %v:\n%s", strings.Join(c.Args, " "), err, output) 69 } 70 } 71 } 72 73 // TestMain calls testMain so that the latter can use defer (TestMain exits with os.Exit). 74 func testMain(m *testing.M) (int, error) { 75 // Because go install -buildmode=shared $standard_library_package always 76 // installs into $GOROOT, here are some gymnastics to come up with a unique 77 // installsuffix to use in this test that we can clean up afterwards. 78 myContext := build.Default 79 runtimeP, err := myContext.Import("runtime", ".", build.ImportComment) 80 if err != nil { 81 return 0, fmt.Errorf("import failed: %v", err) 82 } 83 for i := 0; i < 10000; i++ { 84 try := fmt.Sprintf("%s_%d_dynlink", runtimeP.PkgTargetRoot, rand.Int63()) 85 err = os.Mkdir(try, 0700) 86 if os.IsExist(err) { 87 continue 88 } 89 if err == nil { 90 gorootInstallDir = try 91 } 92 break 93 } 94 if err != nil { 95 return 0, fmt.Errorf("can't create temporary directory: %v", err) 96 } 97 if gorootInstallDir == "" { 98 return 0, errors.New("could not create temporary directory after 10000 tries") 99 } 100 if testing.Verbose() { 101 fmt.Printf("+ mkdir -p %s\n", gorootInstallDir) 102 } 103 defer os.RemoveAll(gorootInstallDir) 104 105 // Some tests need to edit the source in GOPATH, so copy this directory to a 106 // temporary directory and chdir to that. 107 scratchDir, err := ioutil.TempDir("", "testshared") 108 if err != nil { 109 return 0, fmt.Errorf("TempDir failed: %v", err) 110 } 111 if testing.Verbose() { 112 fmt.Printf("+ mkdir -p %s\n", scratchDir) 113 } 114 defer os.RemoveAll(scratchDir) 115 err = filepath.Walk(".", func(path string, info os.FileInfo, err error) error { 116 scratchPath := filepath.Join(scratchDir, path) 117 if info.IsDir() { 118 if path == "." { 119 return nil 120 } 121 if testing.Verbose() { 122 fmt.Printf("+ mkdir -p %s\n", scratchPath) 123 } 124 return os.Mkdir(scratchPath, info.Mode()) 125 } else { 126 fromBytes, err := ioutil.ReadFile(path) 127 if err != nil { 128 return err 129 } 130 if testing.Verbose() { 131 fmt.Printf("+ cp %s %s\n", path, scratchPath) 132 } 133 return ioutil.WriteFile(scratchPath, fromBytes, info.Mode()) 134 } 135 }) 136 if err != nil { 137 return 0, fmt.Errorf("walk failed: %v", err) 138 } 139 os.Setenv("GOPATH", scratchDir) 140 if testing.Verbose() { 141 fmt.Printf("+ export GOPATH=%s\n", scratchDir) 142 } 143 myContext.GOPATH = scratchDir 144 if testing.Verbose() { 145 fmt.Printf("+ cd %s\n", scratchDir) 146 } 147 os.Chdir(scratchDir) 148 149 // All tests depend on runtime being built into a shared library. Because 150 // that takes a few seconds, do it here and have all tests use the version 151 // built here. 152 suffix = strings.Split(filepath.Base(gorootInstallDir), "_")[2] 153 goCmd(nil, append([]string{"install", "-buildmode=shared"}, minpkgs...)...) 154 155 myContext.InstallSuffix = suffix + "_dynlink" 156 depP, err := myContext.Import("depBase", ".", build.ImportComment) 157 if err != nil { 158 return 0, fmt.Errorf("import failed: %v", err) 159 } 160 gopathInstallDir = depP.PkgTargetRoot 161 return m.Run(), nil 162 } 163 164 func TestMain(m *testing.M) { 165 // Some of the tests install binaries into a custom GOPATH. 166 // That won't work if GOBIN is set. 167 os.Unsetenv("GOBIN") 168 169 flag.Parse() 170 exitCode, err := testMain(m) 171 if err != nil { 172 log.Fatal(err) 173 } 174 os.Exit(exitCode) 175 } 176 177 // The shared library was built at the expected location. 178 func TestSOBuilt(t *testing.T) { 179 _, err := os.Stat(filepath.Join(gorootInstallDir, soname)) 180 if err != nil { 181 t.Error(err) 182 } 183 } 184 185 func hasDynTag(f *elf.File, tag elf.DynTag) bool { 186 ds := f.SectionByType(elf.SHT_DYNAMIC) 187 if ds == nil { 188 return false 189 } 190 d, err := ds.Data() 191 if err != nil { 192 return false 193 } 194 for len(d) > 0 { 195 var t elf.DynTag 196 switch f.Class { 197 case elf.ELFCLASS32: 198 t = elf.DynTag(f.ByteOrder.Uint32(d[0:4])) 199 d = d[8:] 200 case elf.ELFCLASS64: 201 t = elf.DynTag(f.ByteOrder.Uint64(d[0:8])) 202 d = d[16:] 203 } 204 if t == tag { 205 return true 206 } 207 } 208 return false 209 } 210 211 // The shared library does not have relocations against the text segment. 212 func TestNoTextrel(t *testing.T) { 213 sopath := filepath.Join(gorootInstallDir, soname) 214 f, err := elf.Open(sopath) 215 if err != nil { 216 t.Fatal("elf.Open failed: ", err) 217 } 218 defer f.Close() 219 if hasDynTag(f, elf.DT_TEXTREL) { 220 t.Errorf("%s has DT_TEXTREL set", soname) 221 } 222 } 223 224 // The shared library does not contain symbols called ".dup" 225 func TestNoDupSymbols(t *testing.T) { 226 sopath := filepath.Join(gorootInstallDir, soname) 227 f, err := elf.Open(sopath) 228 if err != nil { 229 t.Fatal("elf.Open failed: ", err) 230 } 231 defer f.Close() 232 syms, err := f.Symbols() 233 if err != nil { 234 t.Errorf("error reading symbols %v", err) 235 return 236 } 237 for _, s := range syms { 238 if s.Name == ".dup" { 239 t.Fatalf("%s contains symbol called .dup", sopath) 240 } 241 } 242 } 243 244 // The install command should have created a "shlibname" file for the 245 // listed packages (and runtime/cgo, and math on arm) indicating the 246 // name of the shared library containing it. 247 func TestShlibnameFiles(t *testing.T) { 248 pkgs := append([]string{}, minpkgs...) 249 pkgs = append(pkgs, "runtime/cgo") 250 if runtime.GOARCH == "arm" { 251 pkgs = append(pkgs, "math") 252 } 253 for _, pkg := range pkgs { 254 shlibnamefile := filepath.Join(gorootInstallDir, pkg+".shlibname") 255 contentsb, err := ioutil.ReadFile(shlibnamefile) 256 if err != nil { 257 t.Errorf("error reading shlibnamefile for %s: %v", pkg, err) 258 continue 259 } 260 contents := strings.TrimSpace(string(contentsb)) 261 if contents != soname { 262 t.Errorf("shlibnamefile for %s has wrong contents: %q", pkg, contents) 263 } 264 } 265 } 266 267 // Is a given offset into the file contained in a loaded segment? 268 func isOffsetLoaded(f *elf.File, offset uint64) bool { 269 for _, prog := range f.Progs { 270 if prog.Type == elf.PT_LOAD { 271 if prog.Off <= offset && offset < prog.Off+prog.Filesz { 272 return true 273 } 274 } 275 } 276 return false 277 } 278 279 func rnd(v int32, r int32) int32 { 280 if r <= 0 { 281 return v 282 } 283 v += r - 1 284 c := v % r 285 if c < 0 { 286 c += r 287 } 288 v -= c 289 return v 290 } 291 292 func readwithpad(r io.Reader, sz int32) ([]byte, error) { 293 data := make([]byte, rnd(sz, 4)) 294 _, err := io.ReadFull(r, data) 295 if err != nil { 296 return nil, err 297 } 298 data = data[:sz] 299 return data, nil 300 } 301 302 type note struct { 303 name string 304 tag int32 305 desc string 306 section *elf.Section 307 } 308 309 // Read all notes from f. As ELF section names are not supposed to be special, one 310 // looks for a particular note by scanning all SHT_NOTE sections looking for a note 311 // with a particular "name" and "tag". 312 func readNotes(f *elf.File) ([]*note, error) { 313 var notes []*note 314 for _, sect := range f.Sections { 315 if sect.Type != elf.SHT_NOTE { 316 continue 317 } 318 r := sect.Open() 319 for { 320 var namesize, descsize, tag int32 321 err := binary.Read(r, f.ByteOrder, &namesize) 322 if err != nil { 323 if err == io.EOF { 324 break 325 } 326 return nil, fmt.Errorf("read namesize failed: %v", err) 327 } 328 err = binary.Read(r, f.ByteOrder, &descsize) 329 if err != nil { 330 return nil, fmt.Errorf("read descsize failed: %v", err) 331 } 332 err = binary.Read(r, f.ByteOrder, &tag) 333 if err != nil { 334 return nil, fmt.Errorf("read type failed: %v", err) 335 } 336 name, err := readwithpad(r, namesize) 337 if err != nil { 338 return nil, fmt.Errorf("read name failed: %v", err) 339 } 340 desc, err := readwithpad(r, descsize) 341 if err != nil { 342 return nil, fmt.Errorf("read desc failed: %v", err) 343 } 344 notes = append(notes, ¬e{name: string(name), tag: tag, desc: string(desc), section: sect}) 345 } 346 } 347 return notes, nil 348 } 349 350 func dynStrings(t *testing.T, path string, flag elf.DynTag) []string { 351 f, err := elf.Open(path) 352 defer f.Close() 353 if err != nil { 354 t.Fatalf("elf.Open(%q) failed: %v", path, err) 355 } 356 dynstrings, err := f.DynString(flag) 357 if err != nil { 358 t.Fatalf("DynString(%s) failed on %s: %v", flag, path, err) 359 } 360 return dynstrings 361 } 362 363 func AssertIsLinkedToRegexp(t *testing.T, path string, re *regexp.Regexp) { 364 for _, dynstring := range dynStrings(t, path, elf.DT_NEEDED) { 365 if re.MatchString(dynstring) { 366 return 367 } 368 } 369 t.Errorf("%s is not linked to anything matching %v", path, re) 370 } 371 372 func AssertIsLinkedTo(t *testing.T, path, lib string) { 373 AssertIsLinkedToRegexp(t, path, regexp.MustCompile(regexp.QuoteMeta(lib))) 374 } 375 376 func AssertHasRPath(t *testing.T, path, dir string) { 377 for _, tag := range []elf.DynTag{elf.DT_RPATH, elf.DT_RUNPATH} { 378 for _, dynstring := range dynStrings(t, path, tag) { 379 for _, rpath := range strings.Split(dynstring, ":") { 380 if filepath.Clean(rpath) == filepath.Clean(dir) { 381 return 382 } 383 } 384 } 385 } 386 t.Errorf("%s does not have rpath %s", path, dir) 387 } 388 389 // Build a trivial program that links against the shared runtime and check it runs. 390 func TestTrivialExecutable(t *testing.T) { 391 goCmd(t, "install", "-linkshared", "trivial") 392 run(t, "trivial executable", "./bin/trivial") 393 AssertIsLinkedTo(t, "./bin/trivial", soname) 394 AssertHasRPath(t, "./bin/trivial", gorootInstallDir) 395 } 396 397 // Build a trivial program in PIE mode that links against the shared runtime and check it runs. 398 func TestTrivialExecutablePIE(t *testing.T) { 399 goCmd(t, "build", "-buildmode=pie", "-o", "trivial.pie", "-linkshared", "trivial") 400 run(t, "trivial executable", "./trivial.pie") 401 AssertIsLinkedTo(t, "./trivial.pie", soname) 402 AssertHasRPath(t, "./trivial.pie", gorootInstallDir) 403 } 404 405 // Build an executable that uses cgo linked against the shared runtime and check it 406 // runs. 407 func TestCgoExecutable(t *testing.T) { 408 goCmd(t, "install", "-linkshared", "execgo") 409 run(t, "cgo executable", "./bin/execgo") 410 } 411 412 func checkPIE(t *testing.T, name string) { 413 f, err := elf.Open(name) 414 if err != nil { 415 t.Fatal("elf.Open failed: ", err) 416 } 417 defer f.Close() 418 if f.Type != elf.ET_DYN { 419 t.Errorf("%s has type %v, want ET_DYN", name, f.Type) 420 } 421 if hasDynTag(f, elf.DT_TEXTREL) { 422 t.Errorf("%s has DT_TEXTREL set", name) 423 } 424 } 425 426 func TestTrivialPIE(t *testing.T) { 427 name := "trivial_pie" 428 goCmd(t, "build", "-buildmode=pie", "-o="+name, "trivial") 429 defer os.Remove(name) 430 run(t, name, "./"+name) 431 checkPIE(t, name) 432 } 433 434 func TestCgoPIE(t *testing.T) { 435 name := "cgo_pie" 436 goCmd(t, "build", "-buildmode=pie", "-o="+name, "execgo") 437 defer os.Remove(name) 438 run(t, name, "./"+name) 439 checkPIE(t, name) 440 } 441 442 // Build a GOPATH package into a shared library that links against the goroot runtime 443 // and an executable that links against both. 444 func TestGopathShlib(t *testing.T) { 445 goCmd(t, "install", "-buildmode=shared", "-linkshared", "depBase") 446 AssertIsLinkedTo(t, filepath.Join(gopathInstallDir, "libdepBase.so"), soname) 447 goCmd(t, "install", "-linkshared", "exe") 448 AssertIsLinkedTo(t, "./bin/exe", soname) 449 AssertIsLinkedTo(t, "./bin/exe", "libdepBase.so") 450 AssertHasRPath(t, "./bin/exe", gorootInstallDir) 451 AssertHasRPath(t, "./bin/exe", gopathInstallDir) 452 // And check it runs. 453 run(t, "executable linked to GOPATH library", "./bin/exe") 454 } 455 456 // The shared library contains a note listing the packages it contains in a section 457 // that is not mapped into memory. 458 func testPkgListNote(t *testing.T, f *elf.File, note *note) { 459 if note.section.Flags != 0 { 460 t.Errorf("package list section has flags %v", note.section.Flags) 461 } 462 if isOffsetLoaded(f, note.section.Offset) { 463 t.Errorf("package list section contained in PT_LOAD segment") 464 } 465 if note.desc != "depBase\n" { 466 t.Errorf("incorrect package list %q", note.desc) 467 } 468 } 469 470 // The shared library contains a note containing the ABI hash that is mapped into 471 // memory and there is a local symbol called go.link.abihashbytes that points 16 472 // bytes into it. 473 func testABIHashNote(t *testing.T, f *elf.File, note *note) { 474 if note.section.Flags != elf.SHF_ALLOC { 475 t.Errorf("abi hash section has flags %v", note.section.Flags) 476 } 477 if !isOffsetLoaded(f, note.section.Offset) { 478 t.Errorf("abihash section not contained in PT_LOAD segment") 479 } 480 var hashbytes elf.Symbol 481 symbols, err := f.Symbols() 482 if err != nil { 483 t.Errorf("error reading symbols %v", err) 484 return 485 } 486 for _, sym := range symbols { 487 if sym.Name == "go.link.abihashbytes" { 488 hashbytes = sym 489 } 490 } 491 if hashbytes.Name == "" { 492 t.Errorf("no symbol called go.link.abihashbytes") 493 return 494 } 495 if elf.ST_BIND(hashbytes.Info) != elf.STB_LOCAL { 496 t.Errorf("%s has incorrect binding %v", hashbytes.Name, elf.ST_BIND(hashbytes.Info)) 497 } 498 if f.Sections[hashbytes.Section] != note.section { 499 t.Errorf("%s has incorrect section %v", hashbytes.Name, f.Sections[hashbytes.Section].Name) 500 } 501 if hashbytes.Value-note.section.Addr != 16 { 502 t.Errorf("%s has incorrect offset into section %d", hashbytes.Name, hashbytes.Value-note.section.Addr) 503 } 504 } 505 506 // A Go shared library contains a note indicating which other Go shared libraries it 507 // was linked against in an unmapped section. 508 func testDepsNote(t *testing.T, f *elf.File, note *note) { 509 if note.section.Flags != 0 { 510 t.Errorf("package list section has flags %v", note.section.Flags) 511 } 512 if isOffsetLoaded(f, note.section.Offset) { 513 t.Errorf("package list section contained in PT_LOAD segment") 514 } 515 // libdepBase.so just links against the lib containing the runtime. 516 if note.desc != soname { 517 t.Errorf("incorrect dependency list %q", note.desc) 518 } 519 } 520 521 // The shared library contains notes with defined contents; see above. 522 func TestNotes(t *testing.T) { 523 goCmd(t, "install", "-buildmode=shared", "-linkshared", "depBase") 524 f, err := elf.Open(filepath.Join(gopathInstallDir, "libdepBase.so")) 525 if err != nil { 526 t.Fatal(err) 527 } 528 defer f.Close() 529 notes, err := readNotes(f) 530 if err != nil { 531 t.Fatal(err) 532 } 533 pkgListNoteFound := false 534 abiHashNoteFound := false 535 depsNoteFound := false 536 for _, note := range notes { 537 if note.name != "Go\x00\x00" { 538 continue 539 } 540 switch note.tag { 541 case 1: // ELF_NOTE_GOPKGLIST_TAG 542 if pkgListNoteFound { 543 t.Error("multiple package list notes") 544 } 545 testPkgListNote(t, f, note) 546 pkgListNoteFound = true 547 case 2: // ELF_NOTE_GOABIHASH_TAG 548 if abiHashNoteFound { 549 t.Error("multiple abi hash notes") 550 } 551 testABIHashNote(t, f, note) 552 abiHashNoteFound = true 553 case 3: // ELF_NOTE_GODEPS_TAG 554 if depsNoteFound { 555 t.Error("multiple abi hash notes") 556 } 557 testDepsNote(t, f, note) 558 depsNoteFound = true 559 } 560 } 561 if !pkgListNoteFound { 562 t.Error("package list note not found") 563 } 564 if !abiHashNoteFound { 565 t.Error("abi hash note not found") 566 } 567 if !depsNoteFound { 568 t.Error("deps note not found") 569 } 570 } 571 572 // Build a GOPATH package (depBase) into a shared library that links against the goroot 573 // runtime, another package (dep2) that links against the first, and and an 574 // executable that links against dep2. 575 func TestTwoGopathShlibs(t *testing.T) { 576 goCmd(t, "install", "-buildmode=shared", "-linkshared", "depBase") 577 goCmd(t, "install", "-buildmode=shared", "-linkshared", "dep2") 578 goCmd(t, "install", "-linkshared", "exe2") 579 run(t, "executable linked to GOPATH library", "./bin/exe2") 580 } 581 582 func TestThreeGopathShlibs(t *testing.T) { 583 goCmd(t, "install", "-buildmode=shared", "-linkshared", "depBase") 584 goCmd(t, "install", "-buildmode=shared", "-linkshared", "dep2") 585 goCmd(t, "install", "-buildmode=shared", "-linkshared", "dep3") 586 goCmd(t, "install", "-linkshared", "exe3") 587 run(t, "executable linked to GOPATH library", "./bin/exe3") 588 } 589 590 // If gccgo is not available or not new enough call t.Skip. Otherwise, 591 // return a build.Context that is set up for gccgo. 592 func prepGccgo(t *testing.T) build.Context { 593 gccgoName := os.Getenv("GCCGO") 594 if gccgoName == "" { 595 gccgoName = "gccgo" 596 } 597 gccgoPath, err := exec.LookPath(gccgoName) 598 if err != nil { 599 t.Skip("gccgo not found") 600 } 601 cmd := exec.Command(gccgoPath, "-dumpversion") 602 output, err := cmd.CombinedOutput() 603 if err != nil { 604 t.Fatalf("%s -dumpversion failed: %v\n%s", gccgoPath, err, output) 605 } 606 if string(output) < "5" { 607 t.Skipf("gccgo too old (%s)", strings.TrimSpace(string(output))) 608 } 609 gccgoContext := build.Default 610 gccgoContext.InstallSuffix = suffix + "_fPIC" 611 gccgoContext.Compiler = "gccgo" 612 gccgoContext.GOPATH = os.Getenv("GOPATH") 613 return gccgoContext 614 } 615 616 // Build a GOPATH package into a shared library with gccgo and an executable that 617 // links against it. 618 func TestGoPathShlibGccgo(t *testing.T) { 619 gccgoContext := prepGccgo(t) 620 621 libgoRE := regexp.MustCompile("libgo.so.[0-9]+") 622 623 depP, err := gccgoContext.Import("depBase", ".", build.ImportComment) 624 if err != nil { 625 t.Fatalf("import failed: %v", err) 626 } 627 gccgoInstallDir := filepath.Join(depP.PkgTargetRoot, "shlibs") 628 goCmd(t, "install", "-compiler=gccgo", "-buildmode=shared", "-linkshared", "depBase") 629 AssertIsLinkedToRegexp(t, filepath.Join(gccgoInstallDir, "libdepBase.so"), libgoRE) 630 goCmd(t, "install", "-compiler=gccgo", "-linkshared", "exe") 631 AssertIsLinkedToRegexp(t, "./bin/exe", libgoRE) 632 AssertIsLinkedTo(t, "./bin/exe", "libdepBase.so") 633 AssertHasRPath(t, "./bin/exe", gccgoInstallDir) 634 // And check it runs. 635 run(t, "gccgo-built", "./bin/exe") 636 } 637 638 // The gccgo version of TestTwoGopathShlibs: build a GOPATH package into a shared 639 // library with gccgo, another GOPATH package that depends on the first and an 640 // executable that links the second library. 641 func TestTwoGopathShlibsGccgo(t *testing.T) { 642 gccgoContext := prepGccgo(t) 643 644 libgoRE := regexp.MustCompile("libgo.so.[0-9]+") 645 646 depP, err := gccgoContext.Import("depBase", ".", build.ImportComment) 647 if err != nil { 648 t.Fatalf("import failed: %v", err) 649 } 650 gccgoInstallDir := filepath.Join(depP.PkgTargetRoot, "shlibs") 651 goCmd(t, "install", "-compiler=gccgo", "-buildmode=shared", "-linkshared", "depBase") 652 goCmd(t, "install", "-compiler=gccgo", "-buildmode=shared", "-linkshared", "dep2") 653 goCmd(t, "install", "-compiler=gccgo", "-linkshared", "exe2") 654 655 AssertIsLinkedToRegexp(t, filepath.Join(gccgoInstallDir, "libdepBase.so"), libgoRE) 656 AssertIsLinkedToRegexp(t, filepath.Join(gccgoInstallDir, "libdep2.so"), libgoRE) 657 AssertIsLinkedTo(t, filepath.Join(gccgoInstallDir, "libdep2.so"), "libdepBase.so") 658 AssertIsLinkedToRegexp(t, "./bin/exe2", libgoRE) 659 AssertIsLinkedTo(t, "./bin/exe2", "libdep2") 660 AssertIsLinkedTo(t, "./bin/exe2", "libdepBase.so") 661 662 // And check it runs. 663 run(t, "gccgo-built", "./bin/exe2") 664 } 665 666 // Testing rebuilding of shared libraries when they are stale is a bit more 667 // complicated that it seems like it should be. First, we make everything "old": but 668 // only a few seconds old, or it might be older than gc (or the runtime source) and 669 // everything will get rebuilt. Then define a timestamp slightly newer than this 670 // time, which is what we set the mtime to of a file to cause it to be seen as new, 671 // and finally another slightly even newer one that we can compare files against to 672 // see if they have been rebuilt. 673 var oldTime = time.Now().Add(-9 * time.Second) 674 var nearlyNew = time.Now().Add(-6 * time.Second) 675 var stampTime = time.Now().Add(-3 * time.Second) 676 677 // resetFileStamps makes "everything" (bin, src, pkg from GOPATH and the 678 // test-specific parts of GOROOT) appear old. 679 func resetFileStamps() { 680 chtime := func(path string, info os.FileInfo, err error) error { 681 return os.Chtimes(path, oldTime, oldTime) 682 } 683 reset := func(path string) { 684 if err := filepath.Walk(path, chtime); err != nil { 685 log.Fatalf("resetFileStamps failed: %v", err) 686 } 687 688 } 689 reset("bin") 690 reset("pkg") 691 reset("src") 692 reset(gorootInstallDir) 693 } 694 695 // touch makes path newer than the "old" time stamp used by resetFileStamps. 696 func touch(path string) { 697 if err := os.Chtimes(path, nearlyNew, nearlyNew); err != nil { 698 log.Fatalf("os.Chtimes failed: %v", err) 699 } 700 } 701 702 // isNew returns if the path is newer than the time stamp used by touch. 703 func isNew(path string) bool { 704 fi, err := os.Stat(path) 705 if err != nil { 706 log.Fatalf("os.Stat failed: %v", err) 707 } 708 return fi.ModTime().After(stampTime) 709 } 710 711 // Fail unless path has been rebuilt (i.e. is newer than the time stamp used by 712 // isNew) 713 func AssertRebuilt(t *testing.T, msg, path string) { 714 if !isNew(path) { 715 t.Errorf("%s was not rebuilt (%s)", msg, path) 716 } 717 } 718 719 // Fail if path has been rebuilt (i.e. is newer than the time stamp used by isNew) 720 func AssertNotRebuilt(t *testing.T, msg, path string) { 721 if isNew(path) { 722 t.Errorf("%s was rebuilt (%s)", msg, path) 723 } 724 } 725 726 func TestRebuilding(t *testing.T) { 727 goCmd(t, "install", "-buildmode=shared", "-linkshared", "depBase") 728 goCmd(t, "install", "-linkshared", "exe") 729 730 // If the source is newer than both the .a file and the .so, both are rebuilt. 731 resetFileStamps() 732 touch("src/depBase/dep.go") 733 goCmd(t, "install", "-linkshared", "exe") 734 AssertRebuilt(t, "new source", filepath.Join(gopathInstallDir, "depBase.a")) 735 AssertRebuilt(t, "new source", filepath.Join(gopathInstallDir, "libdepBase.so")) 736 737 // If the .a file is newer than the .so, the .so is rebuilt (but not the .a) 738 resetFileStamps() 739 touch(filepath.Join(gopathInstallDir, "depBase.a")) 740 goCmd(t, "install", "-linkshared", "exe") 741 AssertNotRebuilt(t, "new .a file", filepath.Join(gopathInstallDir, "depBase.a")) 742 AssertRebuilt(t, "new .a file", filepath.Join(gopathInstallDir, "libdepBase.so")) 743 } 744 745 func appendFile(path, content string) { 746 f, err := os.OpenFile(path, os.O_WRONLY|os.O_APPEND, 0660) 747 if err != nil { 748 log.Fatalf("os.OpenFile failed: %v", err) 749 } 750 defer func() { 751 err := f.Close() 752 if err != nil { 753 log.Fatalf("f.Close failed: %v", err) 754 } 755 }() 756 _, err = f.WriteString(content) 757 if err != nil { 758 log.Fatalf("f.WriteString failed: %v", err) 759 } 760 } 761 762 func TestABIChecking(t *testing.T) { 763 goCmd(t, "install", "-buildmode=shared", "-linkshared", "depBase") 764 goCmd(t, "install", "-linkshared", "exe") 765 766 // If we make an ABI-breaking change to depBase and rebuild libp.so but not exe, 767 // exe will abort with a complaint on startup. 768 // This assumes adding an exported function breaks ABI, which is not true in 769 // some senses but suffices for the narrow definition of ABI compatibility the 770 // toolchain uses today. 771 resetFileStamps() 772 appendFile("src/depBase/dep.go", "func ABIBreak() {}\n") 773 goCmd(t, "install", "-buildmode=shared", "-linkshared", "depBase") 774 c := exec.Command("./bin/exe") 775 output, err := c.CombinedOutput() 776 if err == nil { 777 t.Fatal("executing exe did not fail after ABI break") 778 } 779 scanner := bufio.NewScanner(bytes.NewReader(output)) 780 foundMsg := false 781 const wantLine = "abi mismatch detected between the executable and libdepBase.so" 782 for scanner.Scan() { 783 if scanner.Text() == wantLine { 784 foundMsg = true 785 break 786 } 787 } 788 if err = scanner.Err(); err != nil { 789 t.Errorf("scanner encountered error: %v", err) 790 } 791 if !foundMsg { 792 t.Fatalf("exe failed, but without line %q; got output:\n%s", wantLine, output) 793 } 794 795 // Rebuilding exe makes it work again. 796 goCmd(t, "install", "-linkshared", "exe") 797 run(t, "rebuilt exe", "./bin/exe") 798 799 // If we make a change which does not break ABI (such as adding an unexported 800 // function) and rebuild libdepBase.so, exe still works. 801 resetFileStamps() 802 appendFile("src/depBase/dep.go", "func noABIBreak() {}\n") 803 goCmd(t, "install", "-buildmode=shared", "-linkshared", "depBase") 804 run(t, "after non-ABI breaking change", "./bin/exe") 805 } 806 807 // If a package 'explicit' imports a package 'implicit', building 808 // 'explicit' into a shared library implicitly includes implicit in 809 // the shared library. Building an executable that imports both 810 // explicit and implicit builds the code from implicit into the 811 // executable rather than fetching it from the shared library. The 812 // link still succeeds and the executable still runs though. 813 func TestImplicitInclusion(t *testing.T) { 814 goCmd(t, "install", "-buildmode=shared", "-linkshared", "explicit") 815 goCmd(t, "install", "-linkshared", "implicitcmd") 816 run(t, "running executable linked against library that contains same package as it", "./bin/implicitcmd") 817 } 818 819 // Tests to make sure that the type fields of empty interfaces and itab 820 // fields of nonempty interfaces are unique even across modules, 821 // so that interface equality works correctly. 822 func TestInterface(t *testing.T) { 823 goCmd(t, "install", "-buildmode=shared", "-linkshared", "iface_a") 824 // Note: iface_i gets installed implicitly as a dependency of iface_a. 825 goCmd(t, "install", "-buildmode=shared", "-linkshared", "iface_b") 826 goCmd(t, "install", "-linkshared", "iface") 827 run(t, "running type/itab uniqueness tester", "./bin/iface") 828 } 829