// Copyright 2011 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Action graph execution. package work import ( "bytes" "context" "encoding/json" "errors" "fmt" "internal/buildcfg" exec "internal/execabs" "internal/lazyregexp" "io" "io/fs" "log" "math/rand" "os" "path/filepath" "regexp" "runtime" "strconv" "strings" "sync" "time" "cmd/go/internal/base" "cmd/go/internal/cache" "cmd/go/internal/cfg" "cmd/go/internal/fsys" "cmd/go/internal/load" "cmd/go/internal/modload" "cmd/go/internal/str" "cmd/go/internal/trace" ) // actionList returns the list of actions in the dag rooted at root // as visited in a depth-first post-order traversal. func actionList(root *Action) []*Action { seen := map[*Action]bool{} all := []*Action{} var walk func(*Action) walk = func(a *Action) { if seen[a] { return } seen[a] = true for _, a1 := range a.Deps { walk(a1) } all = append(all, a) } walk(root) return all } // do runs the action graph rooted at root. func (b *Builder) Do(ctx context.Context, root *Action) { ctx, span := trace.StartSpan(ctx, "exec.Builder.Do ("+root.Mode+" "+root.Target+")") defer span.Done() if !b.IsCmdList { // If we're doing real work, take time at the end to trim the cache. c := cache.Default() defer c.Trim() } // Build list of all actions, assigning depth-first post-order priority. // The original implementation here was a true queue // (using a channel) but it had the effect of getting // distracted by low-level leaf actions to the detriment // of completing higher-level actions. The order of // work does not matter much to overall execution time, // but when running "go test std" it is nice to see each test // results as soon as possible. The priorities assigned // ensure that, all else being equal, the execution prefers // to do what it would have done first in a simple depth-first // dependency order traversal. all := actionList(root) for i, a := range all { a.priority = i } // Write action graph, without timing information, in case we fail and exit early. writeActionGraph := func() { if file := cfg.DebugActiongraph; file != "" { if strings.HasSuffix(file, ".go") { // Do not overwrite Go source code in: // go build -debug-actiongraph x.go base.Fatalf("go: refusing to write action graph to %v\n", file) } js := actionGraphJSON(root) if err := os.WriteFile(file, []byte(js), 0666); err != nil { fmt.Fprintf(os.Stderr, "go: writing action graph: %v\n", err) base.SetExitStatus(1) } } } writeActionGraph() b.readySema = make(chan bool, len(all)) // Initialize per-action execution state. for _, a := range all { for _, a1 := range a.Deps { a1.triggers = append(a1.triggers, a) } a.pending = len(a.Deps) if a.pending == 0 { b.ready.push(a) b.readySema <- true } } // Handle runs a single action and takes care of triggering // any actions that are runnable as a result. handle := func(ctx context.Context, a *Action) { if a.json != nil { a.json.TimeStart = time.Now() } var err error if a.Func != nil && (!a.Failed || a.IgnoreFail) { // TODO(matloob): Better action descriptions desc := "Executing action " if a.Package != nil { desc += "(" + a.Mode + " " + a.Package.Desc() + ")" } ctx, span := trace.StartSpan(ctx, desc) a.traceSpan = span for _, d := range a.Deps { trace.Flow(ctx, d.traceSpan, a.traceSpan) } err = a.Func(b, ctx, a) span.Done() } if a.json != nil { a.json.TimeDone = time.Now() } // The actions run in parallel but all the updates to the // shared work state are serialized through b.exec. b.exec.Lock() defer b.exec.Unlock() if err != nil { if err == errPrintedOutput { base.SetExitStatus(2) } else { base.Errorf("%s", err) } a.Failed = true } for _, a0 := range a.triggers { if a.Failed { a0.Failed = true } if a0.pending--; a0.pending == 0 { b.ready.push(a0) b.readySema <- true } } if a == root { close(b.readySema) } } var wg sync.WaitGroup // Kick off goroutines according to parallelism. // If we are using the -n flag (just printing commands) // drop the parallelism to 1, both to make the output // deterministic and because there is no real work anyway. par := cfg.BuildP if cfg.BuildN { par = 1 } for i := 0; i < par; i++ { wg.Add(1) go func() { ctx := trace.StartGoroutine(ctx) defer wg.Done() for { select { case _, ok := <-b.readySema: if !ok { return } // Receiving a value from b.readySema entitles // us to take from the ready queue. b.exec.Lock() a := b.ready.pop() b.exec.Unlock() handle(ctx, a) case <-base.Interrupted: base.SetExitStatus(1) return } } }() } wg.Wait() // Write action graph again, this time with timing information. writeActionGraph() } // buildActionID computes the action ID for a build action. func (b *Builder) buildActionID(a *Action) cache.ActionID { p := a.Package h := cache.NewHash("build " + p.ImportPath) // Configuration independent of compiler toolchain. // Note: buildmode has already been accounted for in buildGcflags // and should not be inserted explicitly. Most buildmodes use the // same compiler settings and can reuse each other's results. // If not, the reason is already recorded in buildGcflags. fmt.Fprintf(h, "compile\n") // Only include the package directory if it may affect the output. // We trim workspace paths for all packages when -trimpath is set. // The compiler hides the exact value of $GOROOT // when building things in GOROOT. // Assume b.WorkDir is being trimmed properly. // When -trimpath is used with a package built from the module cache, // use the module path and version instead of the directory. if !p.Goroot && !cfg.BuildTrimpath && !strings.HasPrefix(p.Dir, b.WorkDir) { fmt.Fprintf(h, "dir %s\n", p.Dir) } else if cfg.BuildTrimpath && p.Module != nil { fmt.Fprintf(h, "module %s@%s\n", p.Module.Path, p.Module.Version) } if p.Module != nil { fmt.Fprintf(h, "go %s\n", p.Module.GoVersion) } fmt.Fprintf(h, "goos %s goarch %s\n", cfg.Goos, cfg.Goarch) fmt.Fprintf(h, "import %q\n", p.ImportPath) fmt.Fprintf(h, "omitdebug %v standard %v local %v prefix %q\n", p.Internal.OmitDebug, p.Standard, p.Internal.Local, p.Internal.LocalPrefix) if cfg.BuildTrimpath { fmt.Fprintln(h, "trimpath") } if p.Internal.ForceLibrary { fmt.Fprintf(h, "forcelibrary\n") } if len(p.CgoFiles)+len(p.SwigFiles)+len(p.SwigCXXFiles) > 0 { fmt.Fprintf(h, "cgo %q\n", b.toolID("cgo")) cppflags, cflags, cxxflags, fflags, ldflags, _ := b.CFlags(p) ccExe := b.ccExe() fmt.Fprintf(h, "CC=%q %q %q %q\n", ccExe, cppflags, cflags, ldflags) if ccID, err := b.gccToolID(ccExe[0], "c"); err == nil { fmt.Fprintf(h, "CC ID=%q\n", ccID) } if len(p.CXXFiles)+len(p.SwigCXXFiles) > 0 { cxxExe := b.cxxExe() fmt.Fprintf(h, "CXX=%q %q\n", cxxExe, cxxflags) if cxxID, err := b.gccToolID(cxxExe[0], "c++"); err == nil { fmt.Fprintf(h, "CXX ID=%q\n", cxxID) } } if len(p.FFiles) > 0 { fcExe := b.fcExe() fmt.Fprintf(h, "FC=%q %q\n", fcExe, fflags) if fcID, err := b.gccToolID(fcExe[0], "f95"); err == nil { fmt.Fprintf(h, "FC ID=%q\n", fcID) } } // TODO(rsc): Should we include the SWIG version? } if p.Internal.CoverMode != "" { fmt.Fprintf(h, "cover %q %q\n", p.Internal.CoverMode, b.toolID("cover")) } fmt.Fprintf(h, "modinfo %q\n", p.Internal.BuildInfo) // Configuration specific to compiler toolchain. switch cfg.BuildToolchainName { default: base.Fatalf("buildActionID: unknown build toolchain %q", cfg.BuildToolchainName) case "gc": fmt.Fprintf(h, "compile %s %q %q\n", b.toolID("compile"), forcedGcflags, p.Internal.Gcflags) if len(p.SFiles) > 0 { fmt.Fprintf(h, "asm %q %q %q\n", b.toolID("asm"), forcedAsmflags, p.Internal.Asmflags) } // GOARM, GOMIPS, etc. key, val := cfg.GetArchEnv() fmt.Fprintf(h, "%s=%s\n", key, val) if goexperiment := buildcfg.GOEXPERIMENT(); goexperiment != "" { fmt.Fprintf(h, "GOEXPERIMENT=%q\n", goexperiment) } // TODO(rsc): Convince compiler team not to add more magic environment variables, // or perhaps restrict the environment variables passed to subprocesses. // Because these are clumsy, undocumented special-case hacks // for debugging the compiler, they are not settable using 'go env -w', // and so here we use os.Getenv, not cfg.Getenv. magic := []string{ "GOCLOBBERDEADHASH", "GOSSAFUNC", "GOSSADIR", "GOSSAHASH", } for _, env := range magic { if x := os.Getenv(env); x != "" { fmt.Fprintf(h, "magic %s=%s\n", env, x) } } if os.Getenv("GOSSAHASH") != "" { for i := 0; ; i++ { env := fmt.Sprintf("GOSSAHASH%d", i) x := os.Getenv(env) if x == "" { break } fmt.Fprintf(h, "magic %s=%s\n", env, x) } } if os.Getenv("GSHS_LOGFILE") != "" { // Clumsy hack. Compiler writes to this log file, // so do not allow use of cache at all. // We will still write to the cache but it will be // essentially unfindable. fmt.Fprintf(h, "nocache %d\n", time.Now().UnixNano()) } case "gccgo": id, err := b.gccToolID(BuildToolchain.compiler(), "go") if err != nil { base.Fatalf("%v", err) } fmt.Fprintf(h, "compile %s %q %q\n", id, forcedGccgoflags, p.Internal.Gccgoflags) fmt.Fprintf(h, "pkgpath %s\n", gccgoPkgpath(p)) fmt.Fprintf(h, "ar %q\n", BuildToolchain.(gccgoToolchain).ar()) if len(p.SFiles) > 0 { id, _ = b.gccToolID(BuildToolchain.compiler(), "assembler-with-cpp") // Ignore error; different assembler versions // are unlikely to make any difference anyhow. fmt.Fprintf(h, "asm %q\n", id) } } // Input files. inputFiles := str.StringList( p.GoFiles, p.CgoFiles, p.CFiles, p.CXXFiles, p.FFiles, p.MFiles, p.HFiles, p.SFiles, p.SysoFiles, p.SwigFiles, p.SwigCXXFiles, p.EmbedFiles, ) for _, file := range inputFiles { fmt.Fprintf(h, "file %s %s\n", file, b.fileHash(filepath.Join(p.Dir, file))) } for _, a1 := range a.Deps { p1 := a1.Package if p1 != nil { fmt.Fprintf(h, "import %s %s\n", p1.ImportPath, contentID(a1.buildID)) } } return h.Sum() } // needCgoHdr reports whether the actions triggered by this one // expect to be able to access the cgo-generated header file. func (b *Builder) needCgoHdr(a *Action) bool { // If this build triggers a header install, run cgo to get the header. if !b.IsCmdList && (a.Package.UsesCgo() || a.Package.UsesSwig()) && (cfg.BuildBuildmode == "c-archive" || cfg.BuildBuildmode == "c-shared") { for _, t1 := range a.triggers { if t1.Mode == "install header" { return true } } for _, t1 := range a.triggers { for _, t2 := range t1.triggers { if t2.Mode == "install header" { return true } } } } return false } // allowedVersion reports whether the version v is an allowed version of go // (one that we can compile). // v is known to be of the form "1.23". func allowedVersion(v string) bool { // Special case: no requirement. if v == "" { return true } // Special case "1.0" means "go1", which is OK. if v == "1.0" { return true } // Otherwise look through release tags of form "go1.23" for one that matches. for _, tag := range cfg.BuildContext.ReleaseTags { if strings.HasPrefix(tag, "go") && tag[2:] == v { return true } } return false } const ( needBuild uint32 = 1 << iota needCgoHdr needVet needCompiledGoFiles needStale ) // build is the action for building a single package. // Note that any new influence on this logic must be reported in b.buildActionID above as well. func (b *Builder) build(ctx context.Context, a *Action) (err error) { p := a.Package bit := func(x uint32, b bool) uint32 { if b { return x } return 0 } cachedBuild := false need := bit(needBuild, !b.IsCmdList && a.needBuild || b.NeedExport) | bit(needCgoHdr, b.needCgoHdr(a)) | bit(needVet, a.needVet) | bit(needCompiledGoFiles, b.NeedCompiledGoFiles) if !p.BinaryOnly { if b.useCache(a, b.buildActionID(a), p.Target) { // We found the main output in the cache. // If we don't need any other outputs, we can stop. // Otherwise, we need to write files to a.Objdir (needVet, needCgoHdr). // Remember that we might have them in cache // and check again after we create a.Objdir. cachedBuild = true a.output = []byte{} // start saving output in case we miss any cache results need &^= needBuild if b.NeedExport { p.Export = a.built p.BuildID = a.buildID } if need&needCompiledGoFiles != 0 { if err := b.loadCachedSrcFiles(a); err == nil { need &^= needCompiledGoFiles } } } // Source files might be cached, even if the full action is not // (e.g., go list -compiled -find). if !cachedBuild && need&needCompiledGoFiles != 0 { if err := b.loadCachedSrcFiles(a); err == nil { need &^= needCompiledGoFiles } } if need == 0 { return nil } defer b.flushOutput(a) } defer func() { if err != nil && err != errPrintedOutput { err = fmt.Errorf("go build %s: %v", a.Package.ImportPath, err) } if err != nil && b.IsCmdList && b.NeedError && p.Error == nil { p.Error = &load.PackageError{Err: err} } }() if cfg.BuildN { // In -n mode, print a banner between packages. // The banner is five lines so that when changes to // different sections of the bootstrap script have to // be merged, the banners give patch something // to use to find its context. b.Print("\n#\n# " + a.Package.ImportPath + "\n#\n\n") } if cfg.BuildV { b.Print(a.Package.ImportPath + "\n") } if a.Package.BinaryOnly { p.Stale = true p.StaleReason = "binary-only packages are no longer supported" if b.IsCmdList { return nil } return errors.New("binary-only packages are no longer supported") } if err := b.Mkdir(a.Objdir); err != nil { return err } objdir := a.Objdir // Load cached cgo header, but only if we're skipping the main build (cachedBuild==true). if cachedBuild && need&needCgoHdr != 0 { if err := b.loadCachedCgoHdr(a); err == nil { need &^= needCgoHdr } } // Load cached vet config, but only if that's all we have left // (need == needVet, not testing just the one bit). // If we are going to do a full build anyway, // we're going to regenerate the files below anyway. if need == needVet { if err := b.loadCachedVet(a); err == nil { need &^= needVet } } if need == 0 { return nil } if err := allowInstall(a); err != nil { return err } // make target directory dir, _ := filepath.Split(a.Target) if dir != "" { if err := b.Mkdir(dir); err != nil { return err } } gofiles := str.StringList(a.Package.GoFiles) cgofiles := str.StringList(a.Package.CgoFiles) cfiles := str.StringList(a.Package.CFiles) sfiles := str.StringList(a.Package.SFiles) cxxfiles := str.StringList(a.Package.CXXFiles) var objects, cgoObjects, pcCFLAGS, pcLDFLAGS []string if a.Package.UsesCgo() || a.Package.UsesSwig() { if pcCFLAGS, pcLDFLAGS, err = b.getPkgConfigFlags(a.Package); err != nil { return } } // Compute overlays for .c/.cc/.h/etc. and if there are any overlays // put correct contents of all those files in the objdir, to ensure // the correct headers are included. nonGoOverlay is the overlay that // points from nongo files to the copied files in objdir. nonGoFileLists := [][]string{a.Package.CFiles, a.Package.SFiles, a.Package.CXXFiles, a.Package.HFiles, a.Package.FFiles} OverlayLoop: for _, fs := range nonGoFileLists { for _, f := range fs { if _, ok := fsys.OverlayPath(mkAbs(p.Dir, f)); ok { a.nonGoOverlay = make(map[string]string) break OverlayLoop } } } if a.nonGoOverlay != nil { for _, fs := range nonGoFileLists { for i := range fs { from := mkAbs(p.Dir, fs[i]) opath, _ := fsys.OverlayPath(from) dst := objdir + filepath.Base(fs[i]) if err := b.copyFile(dst, opath, 0666, false); err != nil { return err } a.nonGoOverlay[from] = dst } } } // Run SWIG on each .swig and .swigcxx file. // Each run will generate two files, a .go file and a .c or .cxx file. // The .go file will use import "C" and is to be processed by cgo. if a.Package.UsesSwig() { outGo, outC, outCXX, err := b.swig(a, a.Package, objdir, pcCFLAGS) if err != nil { return err } cgofiles = append(cgofiles, outGo...) cfiles = append(cfiles, outC...) cxxfiles = append(cxxfiles, outCXX...) } // If we're doing coverage, preprocess the .go files and put them in the work directory if a.Package.Internal.CoverMode != "" { for i, file := range str.StringList(gofiles, cgofiles) { var sourceFile string var coverFile string var key string if strings.HasSuffix(file, ".cgo1.go") { // cgo files have absolute paths base := filepath.Base(file) sourceFile = file coverFile = objdir + base key = strings.TrimSuffix(base, ".cgo1.go") + ".go" } else { sourceFile = filepath.Join(a.Package.Dir, file) coverFile = objdir + file key = file } coverFile = strings.TrimSuffix(coverFile, ".go") + ".cover.go" cover := a.Package.Internal.CoverVars[key] if cover == nil || base.IsTestFile(file) { // Not covering this file. continue } if err := b.cover(a, coverFile, sourceFile, cover.Var); err != nil { return err } if i < len(gofiles) { gofiles[i] = coverFile } else { cgofiles[i-len(gofiles)] = coverFile } } } // Run cgo. if a.Package.UsesCgo() || a.Package.UsesSwig() { // In a package using cgo, cgo compiles the C, C++ and assembly files with gcc. // There is one exception: runtime/cgo's job is to bridge the // cgo and non-cgo worlds, so it necessarily has files in both. // In that case gcc only gets the gcc_* files. var gccfiles []string gccfiles = append(gccfiles, cfiles...) cfiles = nil if a.Package.Standard && a.Package.ImportPath == "runtime/cgo" { filter := func(files, nongcc, gcc []string) ([]string, []string) { for _, f := range files { if strings.HasPrefix(f, "gcc_") { gcc = append(gcc, f) } else { nongcc = append(nongcc, f) } } return nongcc, gcc } sfiles, gccfiles = filter(sfiles, sfiles[:0], gccfiles) } else { for _, sfile := range sfiles { data, err := os.ReadFile(filepath.Join(a.Package.Dir, sfile)) if err == nil { if bytes.HasPrefix(data, []byte("TEXT")) || bytes.Contains(data, []byte("\nTEXT")) || bytes.HasPrefix(data, []byte("DATA")) || bytes.Contains(data, []byte("\nDATA")) || bytes.HasPrefix(data, []byte("GLOBL")) || bytes.Contains(data, []byte("\nGLOBL")) { return fmt.Errorf("package using cgo has Go assembly file %s", sfile) } } } gccfiles = append(gccfiles, sfiles...) sfiles = nil } outGo, outObj, err := b.cgo(a, base.Tool("cgo"), objdir, pcCFLAGS, pcLDFLAGS, mkAbsFiles(a.Package.Dir, cgofiles), gccfiles, cxxfiles, a.Package.MFiles, a.Package.FFiles) // The files in cxxfiles have now been handled by b.cgo. cxxfiles = nil if err != nil { return err } if cfg.BuildToolchainName == "gccgo" { cgoObjects = append(cgoObjects, a.Objdir+"_cgo_flags") } cgoObjects = append(cgoObjects, outObj...) gofiles = append(gofiles, outGo...) switch cfg.BuildBuildmode { case "c-archive", "c-shared": b.cacheCgoHdr(a) } } var srcfiles []string // .go and non-.go srcfiles = append(srcfiles, gofiles...) srcfiles = append(srcfiles, sfiles...) srcfiles = append(srcfiles, cfiles...) srcfiles = append(srcfiles, cxxfiles...) b.cacheSrcFiles(a, srcfiles) // Running cgo generated the cgo header. need &^= needCgoHdr // Sanity check only, since Package.load already checked as well. if len(gofiles) == 0 { return &load.NoGoError{Package: a.Package} } // Prepare Go vet config if needed. if need&needVet != 0 { buildVetConfig(a, srcfiles) need &^= needVet } if need&needCompiledGoFiles != 0 { if err := b.loadCachedSrcFiles(a); err != nil { return fmt.Errorf("loading compiled Go files from cache: %w", err) } need &^= needCompiledGoFiles } if need == 0 { // Nothing left to do. return nil } // Collect symbol ABI requirements from assembly. symabis, err := BuildToolchain.symabis(b, a, sfiles) if err != nil { return err } // Prepare Go import config. // We start it off with a comment so it can't be empty, so icfg.Bytes() below is never nil. // It should never be empty anyway, but there have been bugs in the past that resulted // in empty configs, which then unfortunately turn into "no config passed to compiler", // and the compiler falls back to looking in pkg itself, which mostly works, // except when it doesn't. var icfg bytes.Buffer fmt.Fprintf(&icfg, "# import config\n") for i, raw := range a.Package.Internal.RawImports { final := a.Package.Imports[i] if final != raw { fmt.Fprintf(&icfg, "importmap %s=%s\n", raw, final) } } for _, a1 := range a.Deps { p1 := a1.Package if p1 == nil || p1.ImportPath == "" || a1.built == "" { continue } fmt.Fprintf(&icfg, "packagefile %s=%s\n", p1.ImportPath, a1.built) } // Prepare Go embed config if needed. // Unlike the import config, it's okay for the embed config to be empty. var embedcfg []byte if len(p.Internal.Embed) > 0 { var embed struct { Patterns map[string][]string Files map[string]string } embed.Patterns = p.Internal.Embed embed.Files = make(map[string]string) for _, file := range p.EmbedFiles { embed.Files[file] = filepath.Join(p.Dir, file) } js, err := json.MarshalIndent(&embed, "", "\t") if err != nil { return fmt.Errorf("marshal embedcfg: %v", err) } embedcfg = js } if p.Internal.BuildInfo != "" && cfg.ModulesEnabled { if err := b.writeFile(objdir+"_gomod_.go", modload.ModInfoProg(p.Internal.BuildInfo, cfg.BuildToolchainName == "gccgo")); err != nil { return err } gofiles = append(gofiles, objdir+"_gomod_.go") } // Compile Go. objpkg := objdir + "_pkg_.a" ofile, out, err := BuildToolchain.gc(b, a, objpkg, icfg.Bytes(), embedcfg, symabis, len(sfiles) > 0, gofiles) if len(out) > 0 { output := b.processOutput(out) if p.Module != nil && !allowedVersion(p.Module.GoVersion) { output += "note: module requires Go " + p.Module.GoVersion + "\n" } b.showOutput(a, a.Package.Dir, a.Package.Desc(), output) if err != nil { return errPrintedOutput } } if err != nil { if p.Module != nil && !allowedVersion(p.Module.GoVersion) { b.showOutput(a, a.Package.Dir, a.Package.Desc(), "note: module requires Go "+p.Module.GoVersion+"\n") } return err } if ofile != objpkg { objects = append(objects, ofile) } // Copy .h files named for goos or goarch or goos_goarch // to names using GOOS and GOARCH. // For example, defs_linux_amd64.h becomes defs_GOOS_GOARCH.h. _goos_goarch := "_" + cfg.Goos + "_" + cfg.Goarch _goos := "_" + cfg.Goos _goarch := "_" + cfg.Goarch for _, file := range a.Package.HFiles { name, ext := fileExtSplit(file) switch { case strings.HasSuffix(name, _goos_goarch): targ := file[:len(name)-len(_goos_goarch)] + "_GOOS_GOARCH." + ext if err := b.copyFile(objdir+targ, filepath.Join(a.Package.Dir, file), 0666, true); err != nil { return err } case strings.HasSuffix(name, _goarch): targ := file[:len(name)-len(_goarch)] + "_GOARCH." + ext if err := b.copyFile(objdir+targ, filepath.Join(a.Package.Dir, file), 0666, true); err != nil { return err } case strings.HasSuffix(name, _goos): targ := file[:len(name)-len(_goos)] + "_GOOS." + ext if err := b.copyFile(objdir+targ, filepath.Join(a.Package.Dir, file), 0666, true); err != nil { return err } } } for _, file := range cfiles { out := file[:len(file)-len(".c")] + ".o" if err := BuildToolchain.cc(b, a, objdir+out, file); err != nil { return err } objects = append(objects, out) } // Assemble .s files. if len(sfiles) > 0 { ofiles, err := BuildToolchain.asm(b, a, sfiles) if err != nil { return err } objects = append(objects, ofiles...) } // For gccgo on ELF systems, we write the build ID as an assembler file. // This lets us set the SHF_EXCLUDE flag. // This is read by readGccgoArchive in cmd/internal/buildid/buildid.go. if a.buildID != "" && cfg.BuildToolchainName == "gccgo" { switch cfg.Goos { case "aix", "android", "dragonfly", "freebsd", "illumos", "linux", "netbsd", "openbsd", "solaris": asmfile, err := b.gccgoBuildIDFile(a) if err != nil { return err } ofiles, err := BuildToolchain.asm(b, a, []string{asmfile}) if err != nil { return err } objects = append(objects, ofiles...) } } // NOTE(rsc): On Windows, it is critically important that the // gcc-compiled objects (cgoObjects) be listed after the ordinary // objects in the archive. I do not know why this is. // https://golang.org/issue/2601 objects = append(objects, cgoObjects...) // Add system object files. for _, syso := range a.Package.SysoFiles { objects = append(objects, filepath.Join(a.Package.Dir, syso)) } // Pack into archive in objdir directory. // If the Go compiler wrote an archive, we only need to add the // object files for non-Go sources to the archive. // If the Go compiler wrote an archive and the package is entirely // Go sources, there is no pack to execute at all. if len(objects) > 0 { if err := BuildToolchain.pack(b, a, objpkg, objects); err != nil { return err } } if err := b.updateBuildID(a, objpkg, true); err != nil { return err } a.built = objpkg return nil } func (b *Builder) cacheObjdirFile(a *Action, c *cache.Cache, name string) error { f, err := os.Open(a.Objdir + name) if err != nil { return err } defer f.Close() _, _, err = c.Put(cache.Subkey(a.actionID, name), f) return err } func (b *Builder) findCachedObjdirFile(a *Action, c *cache.Cache, name string) (string, error) { file, _, err := c.GetFile(cache.Subkey(a.actionID, name)) if err != nil { return "", fmt.Errorf("loading cached file %s: %w", name, err) } return file, nil } func (b *Builder) loadCachedObjdirFile(a *Action, c *cache.Cache, name string) error { cached, err := b.findCachedObjdirFile(a, c, name) if err != nil { return err } return b.copyFile(a.Objdir+name, cached, 0666, true) } func (b *Builder) cacheCgoHdr(a *Action) { c := cache.Default() b.cacheObjdirFile(a, c, "_cgo_install.h") } func (b *Builder) loadCachedCgoHdr(a *Action) error { c := cache.Default() return b.loadCachedObjdirFile(a, c, "_cgo_install.h") } func (b *Builder) cacheSrcFiles(a *Action, srcfiles []string) { c := cache.Default() var buf bytes.Buffer for _, file := range srcfiles { if !strings.HasPrefix(file, a.Objdir) { // not generated buf.WriteString("./") buf.WriteString(file) buf.WriteString("\n") continue } name := file[len(a.Objdir):] buf.WriteString(name) buf.WriteString("\n") if err := b.cacheObjdirFile(a, c, name); err != nil { return } } c.PutBytes(cache.Subkey(a.actionID, "srcfiles"), buf.Bytes()) } func (b *Builder) loadCachedVet(a *Action) error { c := cache.Default() list, _, err := c.GetBytes(cache.Subkey(a.actionID, "srcfiles")) if err != nil { return fmt.Errorf("reading srcfiles list: %w", err) } var srcfiles []string for _, name := range strings.Split(string(list), "\n") { if name == "" { // end of list continue } if strings.HasPrefix(name, "./") { srcfiles = append(srcfiles, name[2:]) continue } if err := b.loadCachedObjdirFile(a, c, name); err != nil { return err } srcfiles = append(srcfiles, a.Objdir+name) } buildVetConfig(a, srcfiles) return nil } func (b *Builder) loadCachedSrcFiles(a *Action) error { c := cache.Default() list, _, err := c.GetBytes(cache.Subkey(a.actionID, "srcfiles")) if err != nil { return fmt.Errorf("reading srcfiles list: %w", err) } var files []string for _, name := range strings.Split(string(list), "\n") { if name == "" { // end of list continue } if strings.HasPrefix(name, "./") { files = append(files, name[len("./"):]) continue } file, err := b.findCachedObjdirFile(a, c, name) if err != nil { return fmt.Errorf("finding %s: %w", name, err) } files = append(files, file) } a.Package.CompiledGoFiles = files return nil } // vetConfig is the configuration passed to vet describing a single package. type vetConfig struct { ID string // package ID (example: "fmt [fmt.test]") Compiler string // compiler name (gc, gccgo) Dir string // directory containing package ImportPath string // canonical import path ("package path") GoFiles []string // absolute paths to package source files NonGoFiles []string // absolute paths to package non-Go files IgnoredFiles []string // absolute paths to ignored source files ImportMap map[string]string // map import path in source code to package path PackageFile map[string]string // map package path to .a file with export data Standard map[string]bool // map package path to whether it's in the standard library PackageVetx map[string]string // map package path to vetx data from earlier vet run VetxOnly bool // only compute vetx data; don't report detected problems VetxOutput string // write vetx data to this output file SucceedOnTypecheckFailure bool // awful hack; see #18395 and below } func buildVetConfig(a *Action, srcfiles []string) { // Classify files based on .go extension. // srcfiles does not include raw cgo files. var gofiles, nongofiles []string for _, name := range srcfiles { if strings.HasSuffix(name, ".go") { gofiles = append(gofiles, name) } else { nongofiles = append(nongofiles, name) } } ignored := str.StringList(a.Package.IgnoredGoFiles, a.Package.IgnoredOtherFiles) // Pass list of absolute paths to vet, // so that vet's error messages will use absolute paths, // so that we can reformat them relative to the directory // in which the go command is invoked. vcfg := &vetConfig{ ID: a.Package.ImportPath, Compiler: cfg.BuildToolchainName, Dir: a.Package.Dir, GoFiles: mkAbsFiles(a.Package.Dir, gofiles), NonGoFiles: mkAbsFiles(a.Package.Dir, nongofiles), IgnoredFiles: mkAbsFiles(a.Package.Dir, ignored), ImportPath: a.Package.ImportPath, ImportMap: make(map[string]string), PackageFile: make(map[string]string), Standard: make(map[string]bool), } a.vetCfg = vcfg for i, raw := range a.Package.Internal.RawImports { final := a.Package.Imports[i] vcfg.ImportMap[raw] = final } // Compute the list of mapped imports in the vet config // so that we can add any missing mappings below. vcfgMapped := make(map[string]bool) for _, p := range vcfg.ImportMap { vcfgMapped[p] = true } for _, a1 := range a.Deps { p1 := a1.Package if p1 == nil || p1.ImportPath == "" { continue } // Add import mapping if needed // (for imports like "runtime/cgo" that appear only in generated code). if !vcfgMapped[p1.ImportPath] { vcfg.ImportMap[p1.ImportPath] = p1.ImportPath } if a1.built != "" { vcfg.PackageFile[p1.ImportPath] = a1.built } if p1.Standard { vcfg.Standard[p1.ImportPath] = true } } } // VetTool is the path to an alternate vet tool binary. // The caller is expected to set it (if needed) before executing any vet actions. var VetTool string // VetFlags are the default flags to pass to vet. // The caller is expected to set them before executing any vet actions. var VetFlags []string // VetExplicit records whether the vet flags were set explicitly on the command line. var VetExplicit bool func (b *Builder) vet(ctx context.Context, a *Action) error { // a.Deps[0] is the build of the package being vetted. // a.Deps[1] is the build of the "fmt" package. a.Failed = false // vet of dependency may have failed but we can still succeed if a.Deps[0].Failed { // The build of the package has failed. Skip vet check. // Vet could return export data for non-typecheck errors, // but we ignore it because the package cannot be compiled. return nil } vcfg := a.Deps[0].vetCfg if vcfg == nil { // Vet config should only be missing if the build failed. return fmt.Errorf("vet config not found") } vcfg.VetxOnly = a.VetxOnly vcfg.VetxOutput = a.Objdir + "vet.out" vcfg.PackageVetx = make(map[string]string) h := cache.NewHash("vet " + a.Package.ImportPath) fmt.Fprintf(h, "vet %q\n", b.toolID("vet")) vetFlags := VetFlags // In GOROOT, we enable all the vet tests during 'go test', // not just the high-confidence subset. This gets us extra // checking for the standard library (at some compliance cost) // and helps us gain experience about how well the checks // work, to help decide which should be turned on by default. // The command-line still wins. // // Note that this flag change applies even when running vet as // a dependency of vetting a package outside std. // (Otherwise we'd have to introduce a whole separate // space of "vet fmt as a dependency of a std top-level vet" // versus "vet fmt as a dependency of a non-std top-level vet".) // This is OK as long as the packages that are farther down the // dependency tree turn on *more* analysis, as here. // (The unsafeptr check does not write any facts for use by // later vet runs, nor does unreachable.) if a.Package.Goroot && !VetExplicit && VetTool == "" { // Turn off -unsafeptr checks. // There's too much unsafe.Pointer code // that vet doesn't like in low-level packages // like runtime, sync, and reflect. // Note that $GOROOT/src/buildall.bash // does the same for the misc-compile trybots // and should be updated if these flags are // changed here. vetFlags = []string{"-unsafeptr=false"} // Also turn off -unreachable checks during go test. // During testing it is very common to make changes // like hard-coded forced returns or panics that make // code unreachable. It's unreasonable to insist on files // not having any unreachable code during "go test". // (buildall.bash still runs with -unreachable enabled // for the overall whole-tree scan.) if cfg.CmdName == "test" { vetFlags = append(vetFlags, "-unreachable=false") } } // Note: We could decide that vet should compute export data for // all analyses, in which case we don't need to include the flags here. // But that would mean that if an analysis causes problems like // unexpected crashes there would be no way to turn it off. // It seems better to let the flags disable export analysis too. fmt.Fprintf(h, "vetflags %q\n", vetFlags) fmt.Fprintf(h, "pkg %q\n", a.Deps[0].actionID) for _, a1 := range a.Deps { if a1.Mode == "vet" && a1.built != "" { fmt.Fprintf(h, "vetout %q %s\n", a1.Package.ImportPath, b.fileHash(a1.built)) vcfg.PackageVetx[a1.Package.ImportPath] = a1.built } } key := cache.ActionID(h.Sum()) if vcfg.VetxOnly && !cfg.BuildA { c := cache.Default() if file, _, err := c.GetFile(key); err == nil { a.built = file return nil } } js, err := json.MarshalIndent(vcfg, "", "\t") if err != nil { return fmt.Errorf("internal error marshaling vet config: %v", err) } js = append(js, '\n') if err := b.writeFile(a.Objdir+"vet.cfg", js); err != nil { return err } // TODO(rsc): Why do we pass $GCCGO to go vet? env := b.cCompilerEnv() if cfg.BuildToolchainName == "gccgo" { env = append(env, "GCCGO="+BuildToolchain.compiler()) } p := a.Package tool := VetTool if tool == "" { tool = base.Tool("vet") } runErr := b.run(a, p.Dir, p.ImportPath, env, cfg.BuildToolexec, tool, vetFlags, a.Objdir+"vet.cfg") // If vet wrote export data, save it for input to future vets. if f, err := os.Open(vcfg.VetxOutput); err == nil { a.built = vcfg.VetxOutput cache.Default().Put(key, f) f.Close() } return runErr } // linkActionID computes the action ID for a link action. func (b *Builder) linkActionID(a *Action) cache.ActionID { p := a.Package h := cache.NewHash("link " + p.ImportPath) // Toolchain-independent configuration. fmt.Fprintf(h, "link\n") fmt.Fprintf(h, "buildmode %s goos %s goarch %s\n", cfg.BuildBuildmode, cfg.Goos, cfg.Goarch) fmt.Fprintf(h, "import %q\n", p.ImportPath) fmt.Fprintf(h, "omitdebug %v standard %v local %v prefix %q\n", p.Internal.OmitDebug, p.Standard, p.Internal.Local, p.Internal.LocalPrefix) if cfg.BuildTrimpath { fmt.Fprintln(h, "trimpath") } // Toolchain-dependent configuration, shared with b.linkSharedActionID. b.printLinkerConfig(h, p) // Input files. for _, a1 := range a.Deps { p1 := a1.Package if p1 != nil { if a1.built != "" || a1.buildID != "" { buildID := a1.buildID if buildID == "" { buildID = b.buildID(a1.built) } fmt.Fprintf(h, "packagefile %s=%s\n", p1.ImportPath, contentID(buildID)) } // Because we put package main's full action ID into the binary's build ID, // we must also put the full action ID into the binary's action ID hash. if p1.Name == "main" { fmt.Fprintf(h, "packagemain %s\n", a1.buildID) } if p1.Shlib != "" { fmt.Fprintf(h, "packageshlib %s=%s\n", p1.ImportPath, contentID(b.buildID(p1.Shlib))) } } } return h.Sum() } // printLinkerConfig prints the linker config into the hash h, // as part of the computation of a linker-related action ID. func (b *Builder) printLinkerConfig(h io.Writer, p *load.Package) { switch cfg.BuildToolchainName { default: base.Fatalf("linkActionID: unknown toolchain %q", cfg.BuildToolchainName) case "gc": fmt.Fprintf(h, "link %s %q %s\n", b.toolID("link"), forcedLdflags, ldBuildmode) if p != nil { fmt.Fprintf(h, "linkflags %q\n", p.Internal.Ldflags) } // GOARM, GOMIPS, etc. key, val := cfg.GetArchEnv() fmt.Fprintf(h, "%s=%s\n", key, val) if goexperiment := buildcfg.GOEXPERIMENT(); goexperiment != "" { fmt.Fprintf(h, "GOEXPERIMENT=%q\n", goexperiment) } // The linker writes source file paths that say GOROOT_FINAL, but // only if -trimpath is not specified (see ld() in gc.go). gorootFinal := cfg.GOROOT_FINAL if cfg.BuildTrimpath { gorootFinal = trimPathGoRootFinal } fmt.Fprintf(h, "GOROOT=%s\n", gorootFinal) // GO_EXTLINK_ENABLED controls whether the external linker is used. fmt.Fprintf(h, "GO_EXTLINK_ENABLED=%s\n", cfg.Getenv("GO_EXTLINK_ENABLED")) // TODO(rsc): Do cgo settings and flags need to be included? // Or external linker settings and flags? case "gccgo": id, err := b.gccToolID(BuildToolchain.linker(), "go") if err != nil { base.Fatalf("%v", err) } fmt.Fprintf(h, "link %s %s\n", id, ldBuildmode) // TODO(iant): Should probably include cgo flags here. } } // link is the action for linking a single command. // Note that any new influence on this logic must be reported in b.linkActionID above as well. func (b *Builder) link(ctx context.Context, a *Action) (err error) { if b.useCache(a, b.linkActionID(a), a.Package.Target) || b.IsCmdList { return nil } defer b.flushOutput(a) if err := b.Mkdir(a.Objdir); err != nil { return err } importcfg := a.Objdir + "importcfg.link" if err := b.writeLinkImportcfg(a, importcfg); err != nil { return err } if err := allowInstall(a); err != nil { return err } // make target directory dir, _ := filepath.Split(a.Target) if dir != "" { if err := b.Mkdir(dir); err != nil { return err } } if err := BuildToolchain.ld(b, a, a.Target, importcfg, a.Deps[0].built); err != nil { return err } // Update the binary with the final build ID. // But if OmitDebug is set, don't rewrite the binary, because we set OmitDebug // on binaries that we are going to run and then delete. // There's no point in doing work on such a binary. // Worse, opening the binary for write here makes it // essentially impossible to safely fork+exec due to a fundamental // incompatibility between ETXTBSY and threads on modern Unix systems. // See golang.org/issue/22220. // We still call updateBuildID to update a.buildID, which is important // for test result caching, but passing rewrite=false (final arg) // means we don't actually rewrite the binary, nor store the // result into the cache. That's probably a net win: // less cache space wasted on large binaries we are not likely to // need again. (On the other hand it does make repeated go test slower.) // It also makes repeated go run slower, which is a win in itself: // we don't want people to treat go run like a scripting environment. if err := b.updateBuildID(a, a.Target, !a.Package.Internal.OmitDebug); err != nil { return err } a.built = a.Target return nil } func (b *Builder) writeLinkImportcfg(a *Action, file string) error { // Prepare Go import cfg. var icfg bytes.Buffer for _, a1 := range a.Deps { p1 := a1.Package if p1 == nil { continue } fmt.Fprintf(&icfg, "packagefile %s=%s\n", p1.ImportPath, a1.built) if p1.Shlib != "" { fmt.Fprintf(&icfg, "packageshlib %s=%s\n", p1.ImportPath, p1.Shlib) } } return b.writeFile(file, icfg.Bytes()) } // PkgconfigCmd returns a pkg-config binary name // defaultPkgConfig is defined in zdefaultcc.go, written by cmd/dist. func (b *Builder) PkgconfigCmd() string { return envList("PKG_CONFIG", cfg.DefaultPkgConfig)[0] } // splitPkgConfigOutput parses the pkg-config output into a slice of // flags. This implements the algorithm from pkgconf/libpkgconf/argvsplit.c. func splitPkgConfigOutput(out []byte) ([]string, error) { if len(out) == 0 { return nil, nil } var flags []string flag := make([]byte, 0, len(out)) escaped := false quote := byte(0) for _, c := range out { if escaped { if quote != 0 { switch c { case '$', '`', '"', '\\': default: flag = append(flag, '\\') } flag = append(flag, c) } else { flag = append(flag, c) } escaped = false } else if quote != 0 { if c == quote { quote = 0 } else { switch c { case '\\': escaped = true default: flag = append(flag, c) } } } else if strings.IndexByte(" \t\n\v\f\r", c) < 0 { switch c { case '\\': escaped = true case '\'', '"': quote = c default: flag = append(flag, c) } } else if len(flag) != 0 { flags = append(flags, string(flag)) flag = flag[:0] } } if escaped { return nil, errors.New("broken character escaping in pkgconf output ") } if quote != 0 { return nil, errors.New("unterminated quoted string in pkgconf output ") } else if len(flag) != 0 { flags = append(flags, string(flag)) } return flags, nil } // Calls pkg-config if needed and returns the cflags/ldflags needed to build the package. func (b *Builder) getPkgConfigFlags(p *load.Package) (cflags, ldflags []string, err error) { if pcargs := p.CgoPkgConfig; len(pcargs) > 0 { // pkg-config permits arguments to appear anywhere in // the command line. Move them all to the front, before --. var pcflags []string var pkgs []string for _, pcarg := range pcargs { if pcarg == "--" { // We're going to add our own "--" argument. } else if strings.HasPrefix(pcarg, "--") { pcflags = append(pcflags, pcarg) } else { pkgs = append(pkgs, pcarg) } } for _, pkg := range pkgs { if !load.SafeArg(pkg) { return nil, nil, fmt.Errorf("invalid pkg-config package name: %s", pkg) } } var out []byte out, err = b.runOut(nil, p.Dir, nil, b.PkgconfigCmd(), "--cflags", pcflags, "--", pkgs) if err != nil { b.showOutput(nil, p.Dir, b.PkgconfigCmd()+" --cflags "+strings.Join(pcflags, " ")+" -- "+strings.Join(pkgs, " "), string(out)) b.Print(err.Error() + "\n") return nil, nil, errPrintedOutput } if len(out) > 0 { cflags, err = splitPkgConfigOutput(out) if err != nil { return nil, nil, err } if err := checkCompilerFlags("CFLAGS", "pkg-config --cflags", cflags); err != nil { return nil, nil, err } } out, err = b.runOut(nil, p.Dir, nil, b.PkgconfigCmd(), "--libs", pcflags, "--", pkgs) if err != nil { b.showOutput(nil, p.Dir, b.PkgconfigCmd()+" --libs "+strings.Join(pcflags, " ")+" -- "+strings.Join(pkgs, " "), string(out)) b.Print(err.Error() + "\n") return nil, nil, errPrintedOutput } if len(out) > 0 { ldflags = strings.Fields(string(out)) if err := checkLinkerFlags("LDFLAGS", "pkg-config --libs", ldflags); err != nil { return nil, nil, err } } } return } func (b *Builder) installShlibname(ctx context.Context, a *Action) error { if err := allowInstall(a); err != nil { return err } // TODO: BuildN a1 := a.Deps[0] err := os.WriteFile(a.Target, []byte(filepath.Base(a1.Target)+"\n"), 0666) if err != nil { return err } if cfg.BuildX { b.Showcmd("", "echo '%s' > %s # internal", filepath.Base(a1.Target), a.Target) } return nil } func (b *Builder) linkSharedActionID(a *Action) cache.ActionID { h := cache.NewHash("linkShared") // Toolchain-independent configuration. fmt.Fprintf(h, "linkShared\n") fmt.Fprintf(h, "goos %s goarch %s\n", cfg.Goos, cfg.Goarch) // Toolchain-dependent configuration, shared with b.linkActionID. b.printLinkerConfig(h, nil) // Input files. for _, a1 := range a.Deps { p1 := a1.Package if a1.built == "" { continue } if p1 != nil { fmt.Fprintf(h, "packagefile %s=%s\n", p1.ImportPath, contentID(b.buildID(a1.built))) if p1.Shlib != "" { fmt.Fprintf(h, "packageshlib %s=%s\n", p1.ImportPath, contentID(b.buildID(p1.Shlib))) } } } // Files named on command line are special. for _, a1 := range a.Deps[0].Deps { p1 := a1.Package fmt.Fprintf(h, "top %s=%s\n", p1.ImportPath, contentID(b.buildID(a1.built))) } return h.Sum() } func (b *Builder) linkShared(ctx context.Context, a *Action) (err error) { if b.useCache(a, b.linkSharedActionID(a), a.Target) || b.IsCmdList { return nil } defer b.flushOutput(a) if err := allowInstall(a); err != nil { return err } if err := b.Mkdir(a.Objdir); err != nil { return err } importcfg := a.Objdir + "importcfg.link" if err := b.writeLinkImportcfg(a, importcfg); err != nil { return err } // TODO(rsc): There is a missing updateBuildID here, // but we have to decide where to store the build ID in these files. a.built = a.Target return BuildToolchain.ldShared(b, a, a.Deps[0].Deps, a.Target, importcfg, a.Deps) } // BuildInstallFunc is the action for installing a single package or executable. func BuildInstallFunc(b *Builder, ctx context.Context, a *Action) (err error) { defer func() { if err != nil && err != errPrintedOutput { // a.Package == nil is possible for the go install -buildmode=shared // action that installs libmangledname.so, which corresponds to // a list of packages, not just one. sep, path := "", "" if a.Package != nil { sep, path = " ", a.Package.ImportPath } err = fmt.Errorf("go %s%s%s: %v", cfg.CmdName, sep, path, err) } }() a1 := a.Deps[0] a.buildID = a1.buildID if a.json != nil { a.json.BuildID = a.buildID } // If we are using the eventual install target as an up-to-date // cached copy of the thing we built, then there's no need to // copy it into itself (and that would probably fail anyway). // In this case a1.built == a.Target because a1.built == p.Target, // so the built target is not in the a1.Objdir tree that b.cleanup(a1) removes. if a1.built == a.Target { a.built = a.Target if !a.buggyInstall { b.cleanup(a1) } // Whether we're smart enough to avoid a complete rebuild // depends on exactly what the staleness and rebuild algorithms // are, as well as potentially the state of the Go build cache. // We don't really want users to be able to infer (or worse start depending on) // those details from whether the modification time changes during // "go install", so do a best-effort update of the file times to make it // look like we rewrote a.Target even if we did not. Updating the mtime // may also help other mtime-based systems that depend on our // previous mtime updates that happened more often. // This is still not perfect - we ignore the error result, and if the file was // unwritable for some reason then pretending to have written it is also // confusing - but it's probably better than not doing the mtime update. // // But don't do that for the special case where building an executable // with -linkshared implicitly installs all its dependent libraries. // We want to hide that awful detail as much as possible, so don't // advertise it by touching the mtimes (usually the libraries are up // to date). if !a.buggyInstall && !b.IsCmdList { if cfg.BuildN { b.Showcmd("", "touch %s", a.Target) } else if err := allowInstall(a); err == nil { now := time.Now() os.Chtimes(a.Target, now, now) } } return nil } // If we're building for go list -export, // never install anything; just keep the cache reference. if b.IsCmdList { a.built = a1.built return nil } if err := allowInstall(a); err != nil { return err } if err := b.Mkdir(a.Objdir); err != nil { return err } perm := fs.FileMode(0666) if a1.Mode == "link" { switch cfg.BuildBuildmode { case "c-archive", "c-shared", "plugin": default: perm = 0777 } } // make target directory dir, _ := filepath.Split(a.Target) if dir != "" { if err := b.Mkdir(dir); err != nil { return err } } if !a.buggyInstall { defer b.cleanup(a1) } return b.moveOrCopyFile(a.Target, a1.built, perm, false) } // allowInstall returns a non-nil error if this invocation of the go command is // allowed to install a.Target. // // (The build of cmd/go running under its own test is forbidden from installing // to its original GOROOT.) var allowInstall = func(*Action) error { return nil } // cleanup removes a's object dir to keep the amount of // on-disk garbage down in a large build. On an operating system // with aggressive buffering, cleaning incrementally like // this keeps the intermediate objects from hitting the disk. func (b *Builder) cleanup(a *Action) { if !cfg.BuildWork { if cfg.BuildX { // Don't say we are removing the directory if // we never created it. if _, err := os.Stat(a.Objdir); err == nil || cfg.BuildN { b.Showcmd("", "rm -r %s", a.Objdir) } } os.RemoveAll(a.Objdir) } } // moveOrCopyFile is like 'mv src dst' or 'cp src dst'. func (b *Builder) moveOrCopyFile(dst, src string, perm fs.FileMode, force bool) error { if cfg.BuildN { b.Showcmd("", "mv %s %s", src, dst) return nil } // If we can update the mode and rename to the dst, do it. // Otherwise fall back to standard copy. // If the source is in the build cache, we need to copy it. if strings.HasPrefix(src, cache.DefaultDir()) { return b.copyFile(dst, src, perm, force) } // On Windows, always copy the file, so that we respect the NTFS // permissions of the parent folder. https://golang.org/issue/22343. // What matters here is not cfg.Goos (the system we are building // for) but runtime.GOOS (the system we are building on). if runtime.GOOS == "windows" { return b.copyFile(dst, src, perm, force) } // If the destination directory has the group sticky bit set, // we have to copy the file to retain the correct permissions. // https://golang.org/issue/18878 if fi, err := os.Stat(filepath.Dir(dst)); err == nil { if fi.IsDir() && (fi.Mode()&fs.ModeSetgid) != 0 { return b.copyFile(dst, src, perm, force) } } // The perm argument is meant to be adjusted according to umask, // but we don't know what the umask is. // Create a dummy file to find out. // This avoids build tags and works even on systems like Plan 9 // where the file mask computation incorporates other information. mode := perm f, err := os.OpenFile(filepath.Clean(dst)+"-go-tmp-umask", os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm) if err == nil { fi, err := f.Stat() if err == nil { mode = fi.Mode() & 0777 } name := f.Name() f.Close() os.Remove(name) } if err := os.Chmod(src, mode); err == nil { if err := os.Rename(src, dst); err == nil { if cfg.BuildX { b.Showcmd("", "mv %s %s", src, dst) } return nil } } return b.copyFile(dst, src, perm, force) } // copyFile is like 'cp src dst'. func (b *Builder) copyFile(dst, src string, perm fs.FileMode, force bool) error { if cfg.BuildN || cfg.BuildX { b.Showcmd("", "cp %s %s", src, dst) if cfg.BuildN { return nil } } sf, err := os.Open(src) if err != nil { return err } defer sf.Close() // Be careful about removing/overwriting dst. // Do not remove/overwrite if dst exists and is a directory // or a non-empty non-object file. if fi, err := os.Stat(dst); err == nil { if fi.IsDir() { return fmt.Errorf("build output %q already exists and is a directory", dst) } if !force && fi.Mode().IsRegular() && fi.Size() != 0 && !isObject(dst) { return fmt.Errorf("build output %q already exists and is not an object file", dst) } } // On Windows, remove lingering ~ file from last attempt. if base.ToolIsWindows { if _, err := os.Stat(dst + "~"); err == nil { os.Remove(dst + "~") } } mayberemovefile(dst) df, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm) if err != nil && base.ToolIsWindows { // Windows does not allow deletion of a binary file // while it is executing. Try to move it out of the way. // If the move fails, which is likely, we'll try again the // next time we do an install of this binary. if err := os.Rename(dst, dst+"~"); err == nil { os.Remove(dst + "~") } df, err = os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm) } if err != nil { return fmt.Errorf("copying %s: %w", src, err) // err should already refer to dst } _, err = io.Copy(df, sf) df.Close() if err != nil { mayberemovefile(dst) return fmt.Errorf("copying %s to %s: %v", src, dst, err) } return nil } // writeFile writes the text to file. func (b *Builder) writeFile(file string, text []byte) error { if cfg.BuildN || cfg.BuildX { b.Showcmd("", "cat >%s << 'EOF' # internal\n%sEOF", file, text) } if cfg.BuildN { return nil } return os.WriteFile(file, text, 0666) } // Install the cgo export header file, if there is one. func (b *Builder) installHeader(ctx context.Context, a *Action) error { src := a.Objdir + "_cgo_install.h" if _, err := os.Stat(src); os.IsNotExist(err) { // If the file does not exist, there are no exported // functions, and we do not install anything. // TODO(rsc): Once we know that caching is rebuilding // at the right times (not missing rebuilds), here we should // probably delete the installed header, if any. if cfg.BuildX { b.Showcmd("", "# %s not created", src) } return nil } if err := allowInstall(a); err != nil { return err } dir, _ := filepath.Split(a.Target) if dir != "" { if err := b.Mkdir(dir); err != nil { return err } } return b.moveOrCopyFile(a.Target, src, 0666, true) } // cover runs, in effect, // go tool cover -mode=b.coverMode -var="varName" -o dst.go src.go func (b *Builder) cover(a *Action, dst, src string, varName string) error { return b.run(a, a.Objdir, "cover "+a.Package.ImportPath, nil, cfg.BuildToolexec, base.Tool("cover"), "-mode", a.Package.Internal.CoverMode, "-var", varName, "-o", dst, src) } var objectMagic = [][]byte{ {'!', '<', 'a', 'r', 'c', 'h', '>', '\n'}, // Package archive {'<', 'b', 'i', 'g', 'a', 'f', '>', '\n'}, // Package AIX big archive {'\x7F', 'E', 'L', 'F'}, // ELF {0xFE, 0xED, 0xFA, 0xCE}, // Mach-O big-endian 32-bit {0xFE, 0xED, 0xFA, 0xCF}, // Mach-O big-endian 64-bit {0xCE, 0xFA, 0xED, 0xFE}, // Mach-O little-endian 32-bit {0xCF, 0xFA, 0xED, 0xFE}, // Mach-O little-endian 64-bit {0x4d, 0x5a, 0x90, 0x00, 0x03, 0x00}, // PE (Windows) as generated by 6l/8l and gcc {0x4d, 0x5a, 0x78, 0x00, 0x01, 0x00}, // PE (Windows) as generated by llvm for dll {0x00, 0x00, 0x01, 0xEB}, // Plan 9 i386 {0x00, 0x00, 0x8a, 0x97}, // Plan 9 amd64 {0x00, 0x00, 0x06, 0x47}, // Plan 9 arm {0x00, 0x61, 0x73, 0x6D}, // WASM {0x01, 0xDF}, // XCOFF 32bit {0x01, 0xF7}, // XCOFF 64bit } func isObject(s string) bool { f, err := os.Open(s) if err != nil { return false } defer f.Close() buf := make([]byte, 64) io.ReadFull(f, buf) for _, magic := range objectMagic { if bytes.HasPrefix(buf, magic) { return true } } return false } // mayberemovefile removes a file only if it is a regular file // When running as a user with sufficient privileges, we may delete // even device files, for example, which is not intended. func mayberemovefile(s string) { if fi, err := os.Lstat(s); err == nil && !fi.Mode().IsRegular() { return } os.Remove(s) } // fmtcmd formats a command in the manner of fmt.Sprintf but also: // // If dir is non-empty and the script is not in dir right now, // fmtcmd inserts "cd dir\n" before the command. // // fmtcmd replaces the value of b.WorkDir with $WORK. // fmtcmd replaces the value of goroot with $GOROOT. // fmtcmd replaces the value of b.gobin with $GOBIN. // // fmtcmd replaces the name of the current directory with dot (.) // but only when it is at the beginning of a space-separated token. // func (b *Builder) fmtcmd(dir string, format string, args ...interface{}) string { cmd := fmt.Sprintf(format, args...) if dir != "" && dir != "/" { dot := " ." if dir[len(dir)-1] == filepath.Separator { dot += string(filepath.Separator) } cmd = strings.ReplaceAll(" "+cmd, " "+dir, dot)[1:] if b.scriptDir != dir { b.scriptDir = dir cmd = "cd " + dir + "\n" + cmd } } if b.WorkDir != "" { cmd = strings.ReplaceAll(cmd, b.WorkDir, "$WORK") escaped := strconv.Quote(b.WorkDir) escaped = escaped[1 : len(escaped)-1] // strip quote characters if escaped != b.WorkDir { cmd = strings.ReplaceAll(cmd, escaped, "$WORK") } } return cmd } // showcmd prints the given command to standard output // for the implementation of -n or -x. func (b *Builder) Showcmd(dir string, format string, args ...interface{}) { b.output.Lock() defer b.output.Unlock() b.Print(b.fmtcmd(dir, format, args...) + "\n") } // showOutput prints "# desc" followed by the given output. // The output is expected to contain references to 'dir', usually // the source directory for the package that has failed to build. // showOutput rewrites mentions of dir with a relative path to dir // when the relative path is shorter. This is usually more pleasant. // For example, if fmt doesn't compile and we are in src/html, // the output is // // $ go build // # fmt // ../fmt/print.go:1090: undefined: asdf // $ // // instead of // // $ go build // # fmt // /usr/gopher/go/src/fmt/print.go:1090: undefined: asdf // $ // // showOutput also replaces references to the work directory with $WORK. // // If a is not nil and a.output is not nil, showOutput appends to that slice instead of // printing to b.Print. // func (b *Builder) showOutput(a *Action, dir, desc, out string) { prefix := "# " + desc suffix := "\n" + out if reldir := base.ShortPath(dir); reldir != dir { suffix = strings.ReplaceAll(suffix, " "+dir, " "+reldir) suffix = strings.ReplaceAll(suffix, "\n"+dir, "\n"+reldir) } suffix = strings.ReplaceAll(suffix, " "+b.WorkDir, " $WORK") if a != nil && a.output != nil { a.output = append(a.output, prefix...) a.output = append(a.output, suffix...) return } b.output.Lock() defer b.output.Unlock() b.Print(prefix, suffix) } // errPrintedOutput is a special error indicating that a command failed // but that it generated output as well, and that output has already // been printed, so there's no point showing 'exit status 1' or whatever // the wait status was. The main executor, builder.do, knows not to // print this error. var errPrintedOutput = errors.New("already printed output - no need to show error") var cgoLine = lazyregexp.New(`\[[^\[\]]+\.(cgo1|cover)\.go:[0-9]+(:[0-9]+)?\]`) var cgoTypeSigRe = lazyregexp.New(`\b_C2?(type|func|var|macro)_\B`) // run runs the command given by cmdline in the directory dir. // If the command fails, run prints information about the failure // and returns a non-nil error. func (b *Builder) run(a *Action, dir string, desc string, env []string, cmdargs ...interface{}) error { out, err := b.runOut(a, dir, env, cmdargs...) if len(out) > 0 { if desc == "" { desc = b.fmtcmd(dir, "%s", strings.Join(str.StringList(cmdargs...), " ")) } b.showOutput(a, dir, desc, b.processOutput(out)) if err != nil { err = errPrintedOutput } } return err } // processOutput prepares the output of runOut to be output to the console. func (b *Builder) processOutput(out []byte) string { if out[len(out)-1] != '\n' { out = append(out, '\n') } messages := string(out) // Fix up output referring to cgo-generated code to be more readable. // Replace x.go:19[/tmp/.../x.cgo1.go:18] with x.go:19. // Replace *[100]_Ctype_foo with *[100]C.foo. // If we're using -x, assume we're debugging and want the full dump, so disable the rewrite. if !cfg.BuildX && cgoLine.MatchString(messages) { messages = cgoLine.ReplaceAllString(messages, "") messages = cgoTypeSigRe.ReplaceAllString(messages, "C.") } return messages } // runOut runs the command given by cmdline in the directory dir. // It returns the command output and any errors that occurred. // It accumulates execution time in a. func (b *Builder) runOut(a *Action, dir string, env []string, cmdargs ...interface{}) ([]byte, error) { cmdline := str.StringList(cmdargs...) for _, arg := range cmdline { // GNU binutils commands, including gcc and gccgo, interpret an argument // @foo anywhere in the command line (even following --) as meaning // "read and insert arguments from the file named foo." // Don't say anything that might be misinterpreted that way. if strings.HasPrefix(arg, "@") { return nil, fmt.Errorf("invalid command-line argument %s in command: %s", arg, joinUnambiguously(cmdline)) } } if cfg.BuildN || cfg.BuildX { var envcmdline string for _, e := range env { if j := strings.IndexByte(e, '='); j != -1 { if strings.ContainsRune(e[j+1:], '\'') { envcmdline += fmt.Sprintf("%s=%q", e[:j], e[j+1:]) } else { envcmdline += fmt.Sprintf("%s='%s'", e[:j], e[j+1:]) } envcmdline += " " } } envcmdline += joinUnambiguously(cmdline) b.Showcmd(dir, "%s", envcmdline) if cfg.BuildN { return nil, nil } } var buf bytes.Buffer cmd := exec.Command(cmdline[0], cmdline[1:]...) if cmd.Path != "" { cmd.Args[0] = cmd.Path } cmd.Stdout = &buf cmd.Stderr = &buf cleanup := passLongArgsInResponseFiles(cmd) defer cleanup() cmd.Dir = dir cmd.Env = base.AppendPWD(os.Environ(), cmd.Dir) // Add the TOOLEXEC_IMPORTPATH environment variable for -toolexec tools. // It doesn't really matter if -toolexec isn't being used. // Note that a.Package.Desc is not really an import path, // but this is consistent with 'go list -f {{.ImportPath}}'. // Plus, it is useful to uniquely identify packages in 'go list -json'. if a != nil && a.Package != nil { cmd.Env = append(cmd.Env, "TOOLEXEC_IMPORTPATH="+a.Package.Desc()) } cmd.Env = append(cmd.Env, env...) start := time.Now() err := cmd.Run() if a != nil && a.json != nil { aj := a.json aj.Cmd = append(aj.Cmd, joinUnambiguously(cmdline)) aj.CmdReal += time.Since(start) if ps := cmd.ProcessState; ps != nil { aj.CmdUser += ps.UserTime() aj.CmdSys += ps.SystemTime() } } // err can be something like 'exit status 1'. // Add information about what program was running. // Note that if buf.Bytes() is non-empty, the caller usually // shows buf.Bytes() and does not print err at all, so the // prefix here does not make most output any more verbose. if err != nil { err = errors.New(cmdline[0] + ": " + err.Error()) } return buf.Bytes(), err } // joinUnambiguously prints the slice, quoting where necessary to make the // output unambiguous. // TODO: See issue 5279. The printing of commands needs a complete redo. func joinUnambiguously(a []string) string { var buf bytes.Buffer for i, s := range a { if i > 0 { buf.WriteByte(' ') } q := strconv.Quote(s) // A gccgo command line can contain -( and -). // Make sure we quote them since they are special to the shell. // The trimpath argument can also contain > (part of =>) and ;. Quote those too. if s == "" || strings.ContainsAny(s, " ()>;") || len(q) > len(s)+2 { buf.WriteString(q) } else { buf.WriteString(s) } } return buf.String() } // cCompilerEnv returns environment variables to set when running the // C compiler. This is needed to disable escape codes in clang error // messages that confuse tools like cgo. func (b *Builder) cCompilerEnv() []string { return []string{"TERM=dumb"} } // mkdir makes the named directory. func (b *Builder) Mkdir(dir string) error { // Make Mkdir(a.Objdir) a no-op instead of an error when a.Objdir == "". if dir == "" { return nil } b.exec.Lock() defer b.exec.Unlock() // We can be a little aggressive about being // sure directories exist. Skip repeated calls. if b.mkdirCache[dir] { return nil } b.mkdirCache[dir] = true if cfg.BuildN || cfg.BuildX { b.Showcmd("", "mkdir -p %s", dir) if cfg.BuildN { return nil } } if err := os.MkdirAll(dir, 0777); err != nil { return err } return nil } // symlink creates a symlink newname -> oldname. func (b *Builder) Symlink(oldname, newname string) error { // It's not an error to try to recreate an existing symlink. if link, err := os.Readlink(newname); err == nil && link == oldname { return nil } if cfg.BuildN || cfg.BuildX { b.Showcmd("", "ln -s %s %s", oldname, newname) if cfg.BuildN { return nil } } return os.Symlink(oldname, newname) } // mkAbs returns an absolute path corresponding to // evaluating f in the directory dir. // We always pass absolute paths of source files so that // the error messages will include the full path to a file // in need of attention. func mkAbs(dir, f string) string { // Leave absolute paths alone. // Also, during -n mode we use the pseudo-directory $WORK // instead of creating an actual work directory that won't be used. // Leave paths beginning with $WORK alone too. if filepath.IsAbs(f) || strings.HasPrefix(f, "$WORK") { return f } return filepath.Join(dir, f) } type toolchain interface { // gc runs the compiler in a specific directory on a set of files // and returns the name of the generated output file. gc(b *Builder, a *Action, archive string, importcfg, embedcfg []byte, symabis string, asmhdr bool, gofiles []string) (ofile string, out []byte, err error) // cc runs the toolchain's C compiler in a directory on a C file // to produce an output file. cc(b *Builder, a *Action, ofile, cfile string) error // asm runs the assembler in a specific directory on specific files // and returns a list of named output files. asm(b *Builder, a *Action, sfiles []string) ([]string, error) // symabis scans the symbol ABIs from sfiles and returns the // path to the output symbol ABIs file, or "" if none. symabis(b *Builder, a *Action, sfiles []string) (string, error) // pack runs the archive packer in a specific directory to create // an archive from a set of object files. // typically it is run in the object directory. pack(b *Builder, a *Action, afile string, ofiles []string) error // ld runs the linker to create an executable starting at mainpkg. ld(b *Builder, root *Action, out, importcfg, mainpkg string) error // ldShared runs the linker to create a shared library containing the pkgs built by toplevelactions ldShared(b *Builder, root *Action, toplevelactions []*Action, out, importcfg string, allactions []*Action) error compiler() string linker() string } type noToolchain struct{} func noCompiler() error { log.Fatalf("unknown compiler %q", cfg.BuildContext.Compiler) return nil } func (noToolchain) compiler() string { noCompiler() return "" } func (noToolchain) linker() string { noCompiler() return "" } func (noToolchain) gc(b *Builder, a *Action, archive string, importcfg, embedcfg []byte, symabis string, asmhdr bool, gofiles []string) (ofile string, out []byte, err error) { return "", nil, noCompiler() } func (noToolchain) asm(b *Builder, a *Action, sfiles []string) ([]string, error) { return nil, noCompiler() } func (noToolchain) symabis(b *Builder, a *Action, sfiles []string) (string, error) { return "", noCompiler() } func (noToolchain) pack(b *Builder, a *Action, afile string, ofiles []string) error { return noCompiler() } func (noToolchain) ld(b *Builder, root *Action, out, importcfg, mainpkg string) error { return noCompiler() } func (noToolchain) ldShared(b *Builder, root *Action, toplevelactions []*Action, out, importcfg string, allactions []*Action) error { return noCompiler() } func (noToolchain) cc(b *Builder, a *Action, ofile, cfile string) error { return noCompiler() } // gcc runs the gcc C compiler to create an object from a single C file. func (b *Builder) gcc(a *Action, p *load.Package, workdir, out string, flags []string, cfile string) error { return b.ccompile(a, p, out, flags, cfile, b.GccCmd(p.Dir, workdir)) } // gxx runs the g++ C++ compiler to create an object from a single C++ file. func (b *Builder) gxx(a *Action, p *load.Package, workdir, out string, flags []string, cxxfile string) error { return b.ccompile(a, p, out, flags, cxxfile, b.GxxCmd(p.Dir, workdir)) } // gfortran runs the gfortran Fortran compiler to create an object from a single Fortran file. func (b *Builder) gfortran(a *Action, p *load.Package, workdir, out string, flags []string, ffile string) error { return b.ccompile(a, p, out, flags, ffile, b.gfortranCmd(p.Dir, workdir)) } // ccompile runs the given C or C++ compiler and creates an object from a single source file. func (b *Builder) ccompile(a *Action, p *load.Package, outfile string, flags []string, file string, compiler []string) error { file = mkAbs(p.Dir, file) desc := p.ImportPath outfile = mkAbs(p.Dir, outfile) // Elide source directory paths if -trimpath or GOROOT_FINAL is set. // This is needed for source files (e.g., a .c file in a package directory). // TODO(golang.org/issue/36072): cgo also generates files with #line // directives pointing to the source directory. It should not generate those // when -trimpath is enabled. if b.gccSupportsFlag(compiler, "-fdebug-prefix-map=a=b") { if cfg.BuildTrimpath { // Keep in sync with Action.trimpath. // The trimmed paths are a little different, but we need to trim in the // same situations. var from, toPath string if m := p.Module; m != nil { from = m.Dir toPath = m.Path + "@" + m.Version } else { from = p.Dir toPath = p.ImportPath } // -fdebug-prefix-map requires an absolute "to" path (or it joins the path // with the working directory). Pick something that makes sense for the // target platform. var to string if cfg.BuildContext.GOOS == "windows" { to = filepath.Join(`\\_\_`, toPath) } else { to = filepath.Join("/_", toPath) } flags = append(flags[:len(flags):len(flags)], "-fdebug-prefix-map="+from+"="+to) } else if p.Goroot && cfg.GOROOT_FINAL != cfg.GOROOT { flags = append(flags[:len(flags):len(flags)], "-fdebug-prefix-map="+cfg.GOROOT+"="+cfg.GOROOT_FINAL) } } overlayPath := file if p, ok := a.nonGoOverlay[overlayPath]; ok { overlayPath = p } output, err := b.runOut(a, filepath.Dir(overlayPath), b.cCompilerEnv(), compiler, flags, "-o", outfile, "-c", filepath.Base(overlayPath)) if len(output) > 0 { // On FreeBSD 11, when we pass -g to clang 3.8 it // invokes its internal assembler with -dwarf-version=2. // When it sees .section .note.GNU-stack, it warns // "DWARF2 only supports one section per compilation unit". // This warning makes no sense, since the section is empty, // but it confuses people. // We work around the problem by detecting the warning // and dropping -g and trying again. if bytes.Contains(output, []byte("DWARF2 only supports one section per compilation unit")) { newFlags := make([]string, 0, len(flags)) for _, f := range flags { if !strings.HasPrefix(f, "-g") { newFlags = append(newFlags, f) } } if len(newFlags) < len(flags) { return b.ccompile(a, p, outfile, newFlags, file, compiler) } } b.showOutput(a, p.Dir, desc, b.processOutput(output)) if err != nil { err = errPrintedOutput } else if os.Getenv("GO_BUILDER_NAME") != "" { return errors.New("C compiler warning promoted to error on Go builders") } } return err } // gccld runs the gcc linker to create an executable from a set of object files. func (b *Builder) gccld(a *Action, p *load.Package, objdir, outfile string, flags []string, objs []string) error { var cmd []string if len(p.CXXFiles) > 0 || len(p.SwigCXXFiles) > 0 { cmd = b.GxxCmd(p.Dir, objdir) } else { cmd = b.GccCmd(p.Dir, objdir) } cmdargs := []interface{}{cmd, "-o", outfile, objs, flags} dir := p.Dir out, err := b.runOut(a, base.Cwd(), b.cCompilerEnv(), cmdargs...) if len(out) > 0 { // Filter out useless linker warnings caused by bugs outside Go. // See also cmd/link/internal/ld's hostlink method. var save [][]byte var skipLines int for _, line := range bytes.SplitAfter(out, []byte("\n")) { // golang.org/issue/26073 - Apple Xcode bug if bytes.Contains(line, []byte("ld: warning: text-based stub file")) { continue } if skipLines > 0 { skipLines-- continue } // Remove duplicate main symbol with runtime/cgo on AIX. // With runtime/cgo, two main are available: // One is generated by cgo tool with {return 0;}. // The other one is the main calling runtime.rt0_go // in runtime/cgo. // The second can't be used by cgo programs because // runtime.rt0_go is unknown to them. // Therefore, we let ld remove this main version // and used the cgo generated one. if p.ImportPath == "runtime/cgo" && bytes.Contains(line, []byte("ld: 0711-224 WARNING: Duplicate symbol: .main")) { skipLines = 1 continue } save = append(save, line) } out = bytes.Join(save, nil) if len(out) > 0 { b.showOutput(nil, dir, p.ImportPath, b.processOutput(out)) if err != nil { err = errPrintedOutput } } } return err } // Grab these before main helpfully overwrites them. var ( origCC = cfg.Getenv("CC") origCXX = cfg.Getenv("CXX") ) // gccCmd returns a gcc command line prefix // defaultCC is defined in zdefaultcc.go, written by cmd/dist. func (b *Builder) GccCmd(incdir, workdir string) []string { return b.compilerCmd(b.ccExe(), incdir, workdir) } // gxxCmd returns a g++ command line prefix // defaultCXX is defined in zdefaultcc.go, written by cmd/dist. func (b *Builder) GxxCmd(incdir, workdir string) []string { return b.compilerCmd(b.cxxExe(), incdir, workdir) } // gfortranCmd returns a gfortran command line prefix. func (b *Builder) gfortranCmd(incdir, workdir string) []string { return b.compilerCmd(b.fcExe(), incdir, workdir) } // ccExe returns the CC compiler setting without all the extra flags we add implicitly. func (b *Builder) ccExe() []string { return b.compilerExe(origCC, cfg.DefaultCC(cfg.Goos, cfg.Goarch)) } // cxxExe returns the CXX compiler setting without all the extra flags we add implicitly. func (b *Builder) cxxExe() []string { return b.compilerExe(origCXX, cfg.DefaultCXX(cfg.Goos, cfg.Goarch)) } // fcExe returns the FC compiler setting without all the extra flags we add implicitly. func (b *Builder) fcExe() []string { return b.compilerExe(cfg.Getenv("FC"), "gfortran") } // compilerExe returns the compiler to use given an // environment variable setting (the value not the name) // and a default. The resulting slice is usually just the name // of the compiler but can have additional arguments if they // were present in the environment value. // For example if CC="gcc -DGOPHER" then the result is ["gcc", "-DGOPHER"]. func (b *Builder) compilerExe(envValue string, def string) []string { compiler := strings.Fields(envValue) if len(compiler) == 0 { compiler = strings.Fields(def) } return compiler } // compilerCmd returns a command line prefix for the given environment // variable and using the default command when the variable is empty. func (b *Builder) compilerCmd(compiler []string, incdir, workdir string) []string { // NOTE: env.go's mkEnv knows that the first three // strings returned are "gcc", "-I", incdir (and cuts them off). a := []string{compiler[0], "-I", incdir} a = append(a, compiler[1:]...) // Definitely want -fPIC but on Windows gcc complains // "-fPIC ignored for target (all code is position independent)" if cfg.Goos != "windows" { a = append(a, "-fPIC") } a = append(a, b.gccArchArgs()...) // gcc-4.5 and beyond require explicit "-pthread" flag // for multithreading with pthread library. if cfg.BuildContext.CgoEnabled { switch cfg.Goos { case "windows": a = append(a, "-mthreads") default: a = append(a, "-pthread") } } if cfg.Goos == "aix" { // mcmodel=large must always be enabled to allow large TOC. a = append(a, "-mcmodel=large") } // disable ASCII art in clang errors, if possible if b.gccSupportsFlag(compiler, "-fno-caret-diagnostics") { a = append(a, "-fno-caret-diagnostics") } // clang is too smart about command-line arguments if b.gccSupportsFlag(compiler, "-Qunused-arguments") { a = append(a, "-Qunused-arguments") } // disable word wrapping in error messages a = append(a, "-fmessage-length=0") // Tell gcc not to include the work directory in object files. if b.gccSupportsFlag(compiler, "-fdebug-prefix-map=a=b") { if workdir == "" { workdir = b.WorkDir } workdir = strings.TrimSuffix(workdir, string(filepath.Separator)) a = append(a, "-fdebug-prefix-map="+workdir+"=/tmp/go-build") } // Tell gcc not to include flags in object files, which defeats the // point of -fdebug-prefix-map above. if b.gccSupportsFlag(compiler, "-gno-record-gcc-switches") { a = append(a, "-gno-record-gcc-switches") } // On OS X, some of the compilers behave as if -fno-common // is always set, and the Mach-O linker in 6l/8l assumes this. // See https://golang.org/issue/3253. if cfg.Goos == "darwin" || cfg.Goos == "ios" { a = append(a, "-fno-common") } return a } // gccNoPie returns the flag to use to request non-PIE. On systems // with PIE (position independent executables) enabled by default, // -no-pie must be passed when doing a partial link with -Wl,-r. // But -no-pie is not supported by all compilers, and clang spells it -nopie. func (b *Builder) gccNoPie(linker []string) string { if b.gccSupportsFlag(linker, "-no-pie") { return "-no-pie" } if b.gccSupportsFlag(linker, "-nopie") { return "-nopie" } return "" } // gccSupportsFlag checks to see if the compiler supports a flag. func (b *Builder) gccSupportsFlag(compiler []string, flag string) bool { key := [2]string{compiler[0], flag} b.exec.Lock() defer b.exec.Unlock() if b, ok := b.flagCache[key]; ok { return b } if b.flagCache == nil { b.flagCache = make(map[[2]string]bool) } tmp := os.DevNull if runtime.GOOS == "windows" { f, err := os.CreateTemp(b.WorkDir, "") if err != nil { return false } f.Close() tmp = f.Name() defer os.Remove(tmp) } // We used to write an empty C file, but that gets complicated with // go build -n. We tried using a file that does not exist, but that // fails on systems with GCC version 4.2.1; that is the last GPLv2 // version of GCC, so some systems have frozen on it. // Now we pass an empty file on stdin, which should work at least for // GCC and clang. cmdArgs := str.StringList(compiler, flag, "-c", "-x", "c", "-", "-o", tmp) if cfg.BuildN || cfg.BuildX { b.Showcmd(b.WorkDir, "%s || true", joinUnambiguously(cmdArgs)) if cfg.BuildN { return false } } cmd := exec.Command(cmdArgs[0], cmdArgs[1:]...) cmd.Dir = b.WorkDir cmd.Env = base.AppendPWD(os.Environ(), cmd.Dir) cmd.Env = append(cmd.Env, "LC_ALL=C") out, _ := cmd.CombinedOutput() // GCC says "unrecognized command line option". // clang says "unknown argument". // Older versions of GCC say "unrecognised debug output level". // For -fsplit-stack GCC says "'-fsplit-stack' is not supported". supported := !bytes.Contains(out, []byte("unrecognized")) && !bytes.Contains(out, []byte("unknown")) && !bytes.Contains(out, []byte("unrecognised")) && !bytes.Contains(out, []byte("is not supported")) b.flagCache[key] = supported return supported } // gccArchArgs returns arguments to pass to gcc based on the architecture. func (b *Builder) gccArchArgs() []string { switch cfg.Goarch { case "386": return []string{"-m32"} case "amd64": if cfg.Goos == "darwin" { return []string{"-arch", "x86_64", "-m64"} } return []string{"-m64"} case "arm64": if cfg.Goos == "darwin" { return []string{"-arch", "arm64"} } case "arm": return []string{"-marm"} // not thumb case "s390x": return []string{"-m64", "-march=z196"} case "mips64", "mips64le": args := []string{"-mabi=64"} if cfg.GOMIPS64 == "hardfloat" { return append(args, "-mhard-float") } else if cfg.GOMIPS64 == "softfloat" { return append(args, "-msoft-float") } case "mips", "mipsle": args := []string{"-mabi=32", "-march=mips32"} if cfg.GOMIPS == "hardfloat" { return append(args, "-mhard-float", "-mfp32", "-mno-odd-spreg") } else if cfg.GOMIPS == "softfloat" { return append(args, "-msoft-float") } case "ppc64": if cfg.Goos == "aix" { return []string{"-maix64"} } } return nil } // envList returns the value of the given environment variable broken // into fields, using the default value when the variable is empty. func envList(key, def string) []string { v := cfg.Getenv(key) if v == "" { v = def } return strings.Fields(v) } // CFlags returns the flags to use when invoking the C, C++ or Fortran compilers, or cgo. func (b *Builder) CFlags(p *load.Package) (cppflags, cflags, cxxflags, fflags, ldflags []string, err error) { defaults := "-g -O2" if cppflags, err = buildFlags("CPPFLAGS", "", p.CgoCPPFLAGS, checkCompilerFlags); err != nil { return } if cflags, err = buildFlags("CFLAGS", defaults, p.CgoCFLAGS, checkCompilerFlags); err != nil { return } if cxxflags, err = buildFlags("CXXFLAGS", defaults, p.CgoCXXFLAGS, checkCompilerFlags); err != nil { return } if fflags, err = buildFlags("FFLAGS", defaults, p.CgoFFLAGS, checkCompilerFlags); err != nil { return } if ldflags, err = buildFlags("LDFLAGS", defaults, p.CgoLDFLAGS, checkLinkerFlags); err != nil { return } return } func buildFlags(name, defaults string, fromPackage []string, check func(string, string, []string) error) ([]string, error) { if err := check(name, "#cgo "+name, fromPackage); err != nil { return nil, err } return str.StringList(envList("CGO_"+name, defaults), fromPackage), nil } var cgoRe = lazyregexp.New(`[/\\:]`) func (b *Builder) cgo(a *Action, cgoExe, objdir string, pcCFLAGS, pcLDFLAGS, cgofiles, gccfiles, gxxfiles, mfiles, ffiles []string) (outGo, outObj []string, err error) { p := a.Package cgoCPPFLAGS, cgoCFLAGS, cgoCXXFLAGS, cgoFFLAGS, cgoLDFLAGS, err := b.CFlags(p) if err != nil { return nil, nil, err } cgoCPPFLAGS = append(cgoCPPFLAGS, pcCFLAGS...) cgoLDFLAGS = append(cgoLDFLAGS, pcLDFLAGS...) // If we are compiling Objective-C code, then we need to link against libobjc if len(mfiles) > 0 { cgoLDFLAGS = append(cgoLDFLAGS, "-lobjc") } // Likewise for Fortran, except there are many Fortran compilers. // Support gfortran out of the box and let others pass the correct link options // via CGO_LDFLAGS if len(ffiles) > 0 { fc := cfg.Getenv("FC") if fc == "" { fc = "gfortran" } if strings.Contains(fc, "gfortran") { cgoLDFLAGS = append(cgoLDFLAGS, "-lgfortran") } } if cfg.BuildMSan { cgoCFLAGS = append([]string{"-fsanitize=memory"}, cgoCFLAGS...) cgoLDFLAGS = append([]string{"-fsanitize=memory"}, cgoLDFLAGS...) } // Allows including _cgo_export.h, as well as the user's .h files, // from .[ch] files in the package. cgoCPPFLAGS = append(cgoCPPFLAGS, "-I", objdir) // cgo // TODO: CGO_FLAGS? gofiles := []string{objdir + "_cgo_gotypes.go"} cfiles := []string{"_cgo_export.c"} for _, fn := range cgofiles { f := strings.TrimSuffix(filepath.Base(fn), ".go") gofiles = append(gofiles, objdir+f+".cgo1.go") cfiles = append(cfiles, f+".cgo2.c") } // TODO: make cgo not depend on $GOARCH? cgoflags := []string{} if p.Standard && p.ImportPath == "runtime/cgo" { cgoflags = append(cgoflags, "-import_runtime_cgo=false") } if p.Standard && (p.ImportPath == "runtime/race" || p.ImportPath == "runtime/msan" || p.ImportPath == "runtime/cgo") { cgoflags = append(cgoflags, "-import_syscall=false") } // Update $CGO_LDFLAGS with p.CgoLDFLAGS. // These flags are recorded in the generated _cgo_gotypes.go file // using //go:cgo_ldflag directives, the compiler records them in the // object file for the package, and then the Go linker passes them // along to the host linker. At this point in the code, cgoLDFLAGS // consists of the original $CGO_LDFLAGS (unchecked) and all the // flags put together from source code (checked). cgoenv := b.cCompilerEnv() if len(cgoLDFLAGS) > 0 { flags := make([]string, len(cgoLDFLAGS)) for i, f := range cgoLDFLAGS { flags[i] = strconv.Quote(f) } cgoenv = append(cgoenv, "CGO_LDFLAGS="+strings.Join(flags, " ")) } if cfg.BuildToolchainName == "gccgo" { if b.gccSupportsFlag([]string{BuildToolchain.compiler()}, "-fsplit-stack") { cgoCFLAGS = append(cgoCFLAGS, "-fsplit-stack") } cgoflags = append(cgoflags, "-gccgo") if pkgpath := gccgoPkgpath(p); pkgpath != "" { cgoflags = append(cgoflags, "-gccgopkgpath="+pkgpath) } } switch cfg.BuildBuildmode { case "c-archive", "c-shared": // Tell cgo that if there are any exported functions // it should generate a header file that C code can // #include. cgoflags = append(cgoflags, "-exportheader="+objdir+"_cgo_install.h") } execdir := p.Dir // Rewrite overlaid paths in cgo files. // cgo adds //line and #line pragmas in generated files with these paths. var trimpath []string for i := range cgofiles { path := mkAbs(p.Dir, cgofiles[i]) if opath, ok := fsys.OverlayPath(path); ok { cgofiles[i] = opath trimpath = append(trimpath, opath+"=>"+path) } } if len(trimpath) > 0 { cgoflags = append(cgoflags, "-trimpath", strings.Join(trimpath, ";")) } if err := b.run(a, execdir, p.ImportPath, cgoenv, cfg.BuildToolexec, cgoExe, "-objdir", objdir, "-importpath", p.ImportPath, cgoflags, "--", cgoCPPFLAGS, cgoCFLAGS, cgofiles); err != nil { return nil, nil, err } outGo = append(outGo, gofiles...) // Use sequential object file names to keep them distinct // and short enough to fit in the .a header file name slots. // We no longer collect them all into _all.o, and we'd like // tools to see both the .o suffix and unique names, so // we need to make them short enough not to be truncated // in the final archive. oseq := 0 nextOfile := func() string { oseq++ return objdir + fmt.Sprintf("_x%03d.o", oseq) } // gcc cflags := str.StringList(cgoCPPFLAGS, cgoCFLAGS) for _, cfile := range cfiles { ofile := nextOfile() if err := b.gcc(a, p, a.Objdir, ofile, cflags, objdir+cfile); err != nil { return nil, nil, err } outObj = append(outObj, ofile) } for _, file := range gccfiles { ofile := nextOfile() if err := b.gcc(a, p, a.Objdir, ofile, cflags, file); err != nil { return nil, nil, err } outObj = append(outObj, ofile) } cxxflags := str.StringList(cgoCPPFLAGS, cgoCXXFLAGS) for _, file := range gxxfiles { ofile := nextOfile() if err := b.gxx(a, p, a.Objdir, ofile, cxxflags, file); err != nil { return nil, nil, err } outObj = append(outObj, ofile) } for _, file := range mfiles { ofile := nextOfile() if err := b.gcc(a, p, a.Objdir, ofile, cflags, file); err != nil { return nil, nil, err } outObj = append(outObj, ofile) } fflags := str.StringList(cgoCPPFLAGS, cgoFFLAGS) for _, file := range ffiles { ofile := nextOfile() if err := b.gfortran(a, p, a.Objdir, ofile, fflags, file); err != nil { return nil, nil, err } outObj = append(outObj, ofile) } switch cfg.BuildToolchainName { case "gc": importGo := objdir + "_cgo_import.go" if err := b.dynimport(a, p, objdir, importGo, cgoExe, cflags, cgoLDFLAGS, outObj); err != nil { return nil, nil, err } outGo = append(outGo, importGo) case "gccgo": defunC := objdir + "_cgo_defun.c" defunObj := objdir + "_cgo_defun.o" if err := BuildToolchain.cc(b, a, defunObj, defunC); err != nil { return nil, nil, err } outObj = append(outObj, defunObj) default: noCompiler() } // Double check the //go:cgo_ldflag comments in the generated files. // The compiler only permits such comments in files whose base name // starts with "_cgo_". Make sure that the comments in those files // are safe. This is a backstop against people somehow smuggling // such a comment into a file generated by cgo. if cfg.BuildToolchainName == "gc" && !cfg.BuildN { var flags []string for _, f := range outGo { if !strings.HasPrefix(filepath.Base(f), "_cgo_") { continue } src, err := os.ReadFile(f) if err != nil { return nil, nil, err } const cgoLdflag = "//go:cgo_ldflag" idx := bytes.Index(src, []byte(cgoLdflag)) for idx >= 0 { // We are looking at //go:cgo_ldflag. // Find start of line. start := bytes.LastIndex(src[:idx], []byte("\n")) if start == -1 { start = 0 } // Find end of line. end := bytes.Index(src[idx:], []byte("\n")) if end == -1 { end = len(src) } else { end += idx } // Check for first line comment in line. // We don't worry about /* */ comments, // which normally won't appear in files // generated by cgo. commentStart := bytes.Index(src[start:], []byte("//")) commentStart += start // If that line comment is //go:cgo_ldflag, // it's a match. if bytes.HasPrefix(src[commentStart:], []byte(cgoLdflag)) { // Pull out the flag, and unquote it. // This is what the compiler does. flag := string(src[idx+len(cgoLdflag) : end]) flag = strings.TrimSpace(flag) flag = strings.Trim(flag, `"`) flags = append(flags, flag) } src = src[end:] idx = bytes.Index(src, []byte(cgoLdflag)) } } // We expect to find the contents of cgoLDFLAGS in flags. if len(cgoLDFLAGS) > 0 { outer: for i := range flags { for j, f := range cgoLDFLAGS { if f != flags[i+j] { continue outer } } flags = append(flags[:i], flags[i+len(cgoLDFLAGS):]...) break } } if err := checkLinkerFlags("LDFLAGS", "go:cgo_ldflag", flags); err != nil { return nil, nil, err } } return outGo, outObj, nil } // dynimport creates a Go source file named importGo containing // //go:cgo_import_dynamic directives for each symbol or library // dynamically imported by the object files outObj. func (b *Builder) dynimport(a *Action, p *load.Package, objdir, importGo, cgoExe string, cflags, cgoLDFLAGS, outObj []string) error { cfile := objdir + "_cgo_main.c" ofile := objdir + "_cgo_main.o" if err := b.gcc(a, p, objdir, ofile, cflags, cfile); err != nil { return err } linkobj := str.StringList(ofile, outObj, mkAbsFiles(p.Dir, p.SysoFiles)) dynobj := objdir + "_cgo_.o" // we need to use -pie for Linux/ARM to get accurate imported sym ldflags := cgoLDFLAGS if (cfg.Goarch == "arm" && cfg.Goos == "linux") || cfg.Goos == "android" { // -static -pie doesn't make sense, and causes link errors. // Issue 26197. n := make([]string, 0, len(ldflags)) for _, flag := range ldflags { if flag != "-static" { n = append(n, flag) } } ldflags = append(n, "-pie") } if err := b.gccld(a, p, objdir, dynobj, ldflags, linkobj); err != nil { return err } // cgo -dynimport var cgoflags []string if p.Standard && p.ImportPath == "runtime/cgo" { cgoflags = []string{"-dynlinker"} // record path to dynamic linker } return b.run(a, base.Cwd(), p.ImportPath, b.cCompilerEnv(), cfg.BuildToolexec, cgoExe, "-dynpackage", p.Name, "-dynimport", dynobj, "-dynout", importGo, cgoflags) } // Run SWIG on all SWIG input files. // TODO: Don't build a shared library, once SWIG emits the necessary // pragmas for external linking. func (b *Builder) swig(a *Action, p *load.Package, objdir string, pcCFLAGS []string) (outGo, outC, outCXX []string, err error) { if err := b.swigVersionCheck(); err != nil { return nil, nil, nil, err } intgosize, err := b.swigIntSize(objdir) if err != nil { return nil, nil, nil, err } for _, f := range p.SwigFiles { goFile, cFile, err := b.swigOne(a, p, f, objdir, pcCFLAGS, false, intgosize) if err != nil { return nil, nil, nil, err } if goFile != "" { outGo = append(outGo, goFile) } if cFile != "" { outC = append(outC, cFile) } } for _, f := range p.SwigCXXFiles { goFile, cxxFile, err := b.swigOne(a, p, f, objdir, pcCFLAGS, true, intgosize) if err != nil { return nil, nil, nil, err } if goFile != "" { outGo = append(outGo, goFile) } if cxxFile != "" { outCXX = append(outCXX, cxxFile) } } return outGo, outC, outCXX, nil } // Make sure SWIG is new enough. var ( swigCheckOnce sync.Once swigCheck error ) func (b *Builder) swigDoVersionCheck() error { out, err := b.runOut(nil, "", nil, "swig", "-version") if err != nil { return err } re := regexp.MustCompile(`[vV]ersion +([\d]+)([.][\d]+)?([.][\d]+)?`) matches := re.FindSubmatch(out) if matches == nil { // Can't find version number; hope for the best. return nil } major, err := strconv.Atoi(string(matches[1])) if err != nil { // Can't find version number; hope for the best. return nil } const errmsg = "must have SWIG version >= 3.0.6" if major < 3 { return errors.New(errmsg) } if major > 3 { // 4.0 or later return nil } // We have SWIG version 3.x. if len(matches[2]) > 0 { minor, err := strconv.Atoi(string(matches[2][1:])) if err != nil { return nil } if minor > 0 { // 3.1 or later return nil } } // We have SWIG version 3.0.x. if len(matches[3]) > 0 { patch, err := strconv.Atoi(string(matches[3][1:])) if err != nil { return nil } if patch < 6 { // Before 3.0.6. return errors.New(errmsg) } } return nil } func (b *Builder) swigVersionCheck() error { swigCheckOnce.Do(func() { swigCheck = b.swigDoVersionCheck() }) return swigCheck } // Find the value to pass for the -intgosize option to swig. var ( swigIntSizeOnce sync.Once swigIntSize string swigIntSizeError error ) // This code fails to build if sizeof(int) <= 32 const swigIntSizeCode = ` package main const i int = 1 << 32 ` // Determine the size of int on the target system for the -intgosize option // of swig >= 2.0.9. Run only once. func (b *Builder) swigDoIntSize(objdir string) (intsize string, err error) { if cfg.BuildN { return "$INTBITS", nil } src := filepath.Join(b.WorkDir, "swig_intsize.go") if err = os.WriteFile(src, []byte(swigIntSizeCode), 0666); err != nil { return } srcs := []string{src} p := load.GoFilesPackage(context.TODO(), load.PackageOpts{}, srcs) if _, _, e := BuildToolchain.gc(b, &Action{Mode: "swigDoIntSize", Package: p, Objdir: objdir}, "", nil, nil, "", false, srcs); e != nil { return "32", nil } return "64", nil } // Determine the size of int on the target system for the -intgosize option // of swig >= 2.0.9. func (b *Builder) swigIntSize(objdir string) (intsize string, err error) { swigIntSizeOnce.Do(func() { swigIntSize, swigIntSizeError = b.swigDoIntSize(objdir) }) return swigIntSize, swigIntSizeError } // Run SWIG on one SWIG input file. func (b *Builder) swigOne(a *Action, p *load.Package, file, objdir string, pcCFLAGS []string, cxx bool, intgosize string) (outGo, outC string, err error) { cgoCPPFLAGS, cgoCFLAGS, cgoCXXFLAGS, _, _, err := b.CFlags(p) if err != nil { return "", "", err } var cflags []string if cxx { cflags = str.StringList(cgoCPPFLAGS, pcCFLAGS, cgoCXXFLAGS) } else { cflags = str.StringList(cgoCPPFLAGS, pcCFLAGS, cgoCFLAGS) } n := 5 // length of ".swig" if cxx { n = 8 // length of ".swigcxx" } base := file[:len(file)-n] goFile := base + ".go" gccBase := base + "_wrap." gccExt := "c" if cxx { gccExt = "cxx" } gccgo := cfg.BuildToolchainName == "gccgo" // swig args := []string{ "-go", "-cgo", "-intgosize", intgosize, "-module", base, "-o", objdir + gccBase + gccExt, "-outdir", objdir, } for _, f := range cflags { if len(f) > 3 && f[:2] == "-I" { args = append(args, f) } } if gccgo { args = append(args, "-gccgo") if pkgpath := gccgoPkgpath(p); pkgpath != "" { args = append(args, "-go-pkgpath", pkgpath) } } if cxx { args = append(args, "-c++") } out, err := b.runOut(a, p.Dir, nil, "swig", args, file) if err != nil { if len(out) > 0 { if bytes.Contains(out, []byte("-intgosize")) || bytes.Contains(out, []byte("-cgo")) { return "", "", errors.New("must have SWIG version >= 3.0.6") } b.showOutput(a, p.Dir, p.Desc(), b.processOutput(out)) // swig error return "", "", errPrintedOutput } return "", "", err } if len(out) > 0 { b.showOutput(a, p.Dir, p.Desc(), b.processOutput(out)) // swig warning } // If the input was x.swig, the output is x.go in the objdir. // But there might be an x.go in the original dir too, and if it // uses cgo as well, cgo will be processing both and will // translate both into x.cgo1.go in the objdir, overwriting one. // Rename x.go to _x_swig.go to avoid this problem. // We ignore files in the original dir that begin with underscore // so _x_swig.go cannot conflict with an original file we were // going to compile. goFile = objdir + goFile newGoFile := objdir + "_" + base + "_swig.go" if err := os.Rename(goFile, newGoFile); err != nil { return "", "", err } return newGoFile, objdir + gccBase + gccExt, nil } // disableBuildID adjusts a linker command line to avoid creating a // build ID when creating an object file rather than an executable or // shared library. Some systems, such as Ubuntu, always add // --build-id to every link, but we don't want a build ID when we are // producing an object file. On some of those system a plain -r (not // -Wl,-r) will turn off --build-id, but clang 3.0 doesn't support a // plain -r. I don't know how to turn off --build-id when using clang // other than passing a trailing --build-id=none. So that is what we // do, but only on systems likely to support it, which is to say, // systems that normally use gold or the GNU linker. func (b *Builder) disableBuildID(ldflags []string) []string { switch cfg.Goos { case "android", "dragonfly", "linux", "netbsd": ldflags = append(ldflags, "-Wl,--build-id=none") } return ldflags } // mkAbsFiles converts files into a list of absolute files, // assuming they were originally relative to dir, // and returns that new list. func mkAbsFiles(dir string, files []string) []string { abs := make([]string, len(files)) for i, f := range files { if !filepath.IsAbs(f) { f = filepath.Join(dir, f) } abs[i] = f } return abs } // passLongArgsInResponseFiles modifies cmd such that, for // certain programs, long arguments are passed in "response files", a // file on disk with the arguments, with one arg per line. An actual // argument starting with '@' means that the rest of the argument is // a filename of arguments to expand. // // See issues 18468 (Windows) and 37768 (Darwin). func passLongArgsInResponseFiles(cmd *exec.Cmd) (cleanup func()) { cleanup = func() {} // no cleanup by default var argLen int for _, arg := range cmd.Args { argLen += len(arg) } // If we're not approaching 32KB of args, just pass args normally. // (use 30KB instead to be conservative; not sure how accounting is done) if !useResponseFile(cmd.Path, argLen) { return } tf, err := os.CreateTemp("", "args") if err != nil { log.Fatalf("error writing long arguments to response file: %v", err) } cleanup = func() { os.Remove(tf.Name()) } var buf bytes.Buffer for _, arg := range cmd.Args[1:] { fmt.Fprintf(&buf, "%s\n", encodeArg(arg)) } if _, err := tf.Write(buf.Bytes()); err != nil { tf.Close() cleanup() log.Fatalf("error writing long arguments to response file: %v", err) } if err := tf.Close(); err != nil { cleanup() log.Fatalf("error writing long arguments to response file: %v", err) } cmd.Args = []string{cmd.Args[0], "@" + tf.Name()} return cleanup } // Windows has a limit of 32 KB arguments. To be conservative and not worry // about whether that includes spaces or not, just use 30 KB. Darwin's limit is // less clear. The OS claims 256KB, but we've seen failures with arglen as // small as 50KB. const ArgLengthForResponseFile = (30 << 10) func useResponseFile(path string, argLen int) bool { // Unless the program uses objabi.Flagparse, which understands // response files, don't use response files. // TODO: do we need more commands? asm? cgo? For now, no. prog := strings.TrimSuffix(filepath.Base(path), ".exe") switch prog { case "compile", "link": default: return false } if argLen > ArgLengthForResponseFile { return true } // On the Go build system, use response files about 10% of the // time, just to exercise this codepath. isBuilder := os.Getenv("GO_BUILDER_NAME") != "" if isBuilder && rand.Intn(10) == 0 { return true } return false } // encodeArg encodes an argument for response file writing. func encodeArg(arg string) string { // If there aren't any characters we need to reencode, fastpath out. if !strings.ContainsAny(arg, "\\\n") { return arg } var b strings.Builder for _, r := range arg { switch r { case '\\': b.WriteByte('\\') b.WriteByte('\\') case '\n': b.WriteByte('\\') b.WriteByte('n') default: b.WriteRune(r) } } return b.String() }