| // 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. |
| |
| package work |
| |
| import ( |
| "bufio" |
| "bytes" |
| "fmt" |
| "io" |
| "io/ioutil" |
| "log" |
| "os" |
| "path/filepath" |
| "runtime" |
| "strings" |
| |
| "cmd/go/internal/base" |
| "cmd/go/internal/cfg" |
| "cmd/go/internal/load" |
| "cmd/go/internal/str" |
| "cmd/internal/objabi" |
| "cmd/internal/sys" |
| "crypto/sha1" |
| ) |
| |
| // The Go toolchain. |
| |
| type gcToolchain struct{} |
| |
| func (gcToolchain) compiler() string { |
| return base.Tool("compile") |
| } |
| |
| func (gcToolchain) linker() string { |
| return base.Tool("link") |
| } |
| |
| func pkgPath(a *Action) string { |
| p := a.Package |
| ppath := p.ImportPath |
| if cfg.BuildBuildmode == "plugin" { |
| ppath = pluginPath(a) |
| } else if p.Name == "main" && !p.Internal.ForceLibrary { |
| ppath = "main" |
| } |
| return ppath |
| } |
| |
| func (gcToolchain) gc(b *Builder, a *Action, archive string, importcfg []byte, symabis string, asmhdr bool, gofiles []string) (ofile string, output []byte, err error) { |
| p := a.Package |
| objdir := a.Objdir |
| if archive != "" { |
| ofile = archive |
| } else { |
| out := "_go_.o" |
| ofile = objdir + out |
| } |
| |
| pkgpath := pkgPath(a) |
| gcargs := []string{"-p", pkgpath} |
| if p.Module != nil && p.Module.GoVersion != "" && allowedVersion(p.Module.GoVersion) { |
| gcargs = append(gcargs, "-lang=go"+p.Module.GoVersion) |
| } |
| if p.Standard { |
| gcargs = append(gcargs, "-std") |
| } |
| compilingRuntime := p.Standard && (p.ImportPath == "runtime" || strings.HasPrefix(p.ImportPath, "runtime/internal")) |
| // The runtime package imports a couple of general internal packages. |
| if p.Standard && (p.ImportPath == "internal/cpu" || p.ImportPath == "internal/bytealg") { |
| compilingRuntime = true |
| } |
| if compilingRuntime { |
| // runtime compiles with a special gc flag to check for |
| // memory allocations that are invalid in the runtime package, |
| // and to implement some special compiler pragmas. |
| gcargs = append(gcargs, "-+") |
| } |
| |
| // If we're giving the compiler the entire package (no C etc files), tell it that, |
| // so that it can give good error messages about forward declarations. |
| // Exceptions: a few standard packages have forward declarations for |
| // pieces supplied behind-the-scenes by package runtime. |
| extFiles := len(p.CgoFiles) + len(p.CFiles) + len(p.CXXFiles) + len(p.MFiles) + len(p.FFiles) + len(p.SFiles) + len(p.SysoFiles) + len(p.SwigFiles) + len(p.SwigCXXFiles) |
| if p.Standard { |
| switch p.ImportPath { |
| case "bytes", "internal/poll", "net", "os", "runtime/pprof", "runtime/trace", "sync", "syscall", "time": |
| extFiles++ |
| } |
| } |
| if extFiles == 0 { |
| gcargs = append(gcargs, "-complete") |
| } |
| if cfg.BuildContext.InstallSuffix != "" { |
| gcargs = append(gcargs, "-installsuffix", cfg.BuildContext.InstallSuffix) |
| } |
| if a.buildID != "" { |
| gcargs = append(gcargs, "-buildid", a.buildID) |
| } |
| if p.Internal.OmitDebug || cfg.Goos == "plan9" || cfg.Goarch == "wasm" { |
| gcargs = append(gcargs, "-dwarf=false") |
| } |
| if strings.HasPrefix(runtimeVersion, "go1") && !strings.Contains(os.Args[0], "go_bootstrap") { |
| gcargs = append(gcargs, "-goversion", runtimeVersion) |
| } |
| if symabis != "" { |
| gcargs = append(gcargs, "-symabis", symabis) |
| } |
| |
| gcflags := str.StringList(forcedGcflags, p.Internal.Gcflags) |
| if compilingRuntime { |
| // Remove -N, if present. |
| // It is not possible to build the runtime with no optimizations, |
| // because the compiler cannot eliminate enough write barriers. |
| for i := 0; i < len(gcflags); i++ { |
| if gcflags[i] == "-N" { |
| copy(gcflags[i:], gcflags[i+1:]) |
| gcflags = gcflags[:len(gcflags)-1] |
| i-- |
| } |
| } |
| } |
| |
| args := []interface{}{cfg.BuildToolexec, base.Tool("compile"), "-o", ofile, "-trimpath", a.trimpath(), gcflags, gcargs, "-D", p.Internal.LocalPrefix} |
| if importcfg != nil { |
| if err := b.writeFile(objdir+"importcfg", importcfg); err != nil { |
| return "", nil, err |
| } |
| args = append(args, "-importcfg", objdir+"importcfg") |
| } |
| if ofile == archive { |
| args = append(args, "-pack") |
| } |
| if asmhdr { |
| args = append(args, "-asmhdr", objdir+"go_asm.h") |
| } |
| |
| // Add -c=N to use concurrent backend compilation, if possible. |
| if c := gcBackendConcurrency(gcflags); c > 1 { |
| args = append(args, fmt.Sprintf("-c=%d", c)) |
| } |
| |
| for _, f := range gofiles { |
| args = append(args, mkAbs(p.Dir, f)) |
| } |
| |
| output, err = b.runOut(a, p.Dir, nil, args...) |
| return ofile, output, err |
| } |
| |
| // gcBackendConcurrency returns the backend compiler concurrency level for a package compilation. |
| func gcBackendConcurrency(gcflags []string) int { |
| // First, check whether we can use -c at all for this compilation. |
| canDashC := concurrentGCBackendCompilationEnabledByDefault |
| |
| switch e := os.Getenv("GO19CONCURRENTCOMPILATION"); e { |
| case "0": |
| canDashC = false |
| case "1": |
| canDashC = true |
| case "": |
| // Not set. Use default. |
| default: |
| log.Fatalf("GO19CONCURRENTCOMPILATION must be 0, 1, or unset, got %q", e) |
| } |
| |
| CheckFlags: |
| for _, flag := range gcflags { |
| // Concurrent compilation is presumed incompatible with any gcflags, |
| // except for known commonly used flags. |
| // If the user knows better, they can manually add their own -c to the gcflags. |
| switch flag { |
| case "-N", "-l", "-S", "-B", "-C", "-I": |
| // OK |
| default: |
| canDashC = false |
| break CheckFlags |
| } |
| } |
| |
| // TODO: Test and delete these conditions. |
| if objabi.Fieldtrack_enabled != 0 || objabi.Preemptibleloops_enabled != 0 { |
| canDashC = false |
| } |
| |
| if !canDashC { |
| return 1 |
| } |
| |
| // Decide how many concurrent backend compilations to allow. |
| // |
| // If we allow too many, in theory we might end up with p concurrent processes, |
| // each with c concurrent backend compiles, all fighting over the same resources. |
| // However, in practice, that seems not to happen too much. |
| // Most build graphs are surprisingly serial, so p==1 for much of the build. |
| // Furthermore, concurrent backend compilation is only enabled for a part |
| // of the overall compiler execution, so c==1 for much of the build. |
| // So don't worry too much about that interaction for now. |
| // |
| // However, in practice, setting c above 4 tends not to help very much. |
| // See the analysis in CL 41192. |
| // |
| // TODO(josharian): attempt to detect whether this particular compilation |
| // is likely to be a bottleneck, e.g. when: |
| // - it has no successor packages to compile (usually package main) |
| // - all paths through the build graph pass through it |
| // - critical path scheduling says it is high priority |
| // and in such a case, set c to runtime.NumCPU. |
| // We do this now when p==1. |
| if cfg.BuildP == 1 { |
| // No process parallelism. Max out c. |
| return runtime.NumCPU() |
| } |
| // Some process parallelism. Set c to min(4, numcpu). |
| c := 4 |
| if ncpu := runtime.NumCPU(); ncpu < c { |
| c = ncpu |
| } |
| return c |
| } |
| |
| // trimpath returns the -trimpath argument to use |
| // when compiling the action. |
| func (a *Action) trimpath() string { |
| // Keep in sync with Builder.ccompile |
| // The trimmed paths are a little different, but we need to trim in the |
| // same situations. |
| |
| // Strip the object directory entirely. |
| objdir := a.Objdir |
| if len(objdir) > 1 && objdir[len(objdir)-1] == filepath.Separator { |
| objdir = objdir[:len(objdir)-1] |
| } |
| rewrite := objdir + "=>" |
| |
| // For "go build -trimpath", rewrite package source directory |
| // to a file system-independent path (just the import path). |
| if cfg.BuildTrimpath { |
| if m := a.Package.Module; m != nil && m.Version != "" { |
| rewrite += ";" + a.Package.Dir + "=>" + m.Path + "@" + m.Version + strings.TrimPrefix(a.Package.ImportPath, m.Path) |
| } else { |
| rewrite += ";" + a.Package.Dir + "=>" + a.Package.ImportPath |
| } |
| } |
| |
| return rewrite |
| } |
| |
| func asmArgs(a *Action, p *load.Package) []interface{} { |
| // Add -I pkg/GOOS_GOARCH so #include "textflag.h" works in .s files. |
| inc := filepath.Join(cfg.GOROOT, "pkg", "include") |
| pkgpath := pkgPath(a) |
| args := []interface{}{cfg.BuildToolexec, base.Tool("asm"), "-p", pkgpath, "-trimpath", a.trimpath(), "-I", a.Objdir, "-I", inc, "-D", "GOOS_" + cfg.Goos, "-D", "GOARCH_" + cfg.Goarch, forcedAsmflags, p.Internal.Asmflags} |
| if p.ImportPath == "runtime" && cfg.Goarch == "386" { |
| for _, arg := range forcedAsmflags { |
| if arg == "-dynlink" { |
| args = append(args, "-D=GOBUILDMODE_shared=1") |
| } |
| } |
| } |
| |
| if cfg.Goarch == "mips" || cfg.Goarch == "mipsle" { |
| // Define GOMIPS_value from cfg.GOMIPS. |
| args = append(args, "-D", "GOMIPS_"+cfg.GOMIPS) |
| } |
| |
| if cfg.Goarch == "mips64" || cfg.Goarch == "mips64le" { |
| // Define GOMIPS64_value from cfg.GOMIPS64. |
| args = append(args, "-D", "GOMIPS64_"+cfg.GOMIPS64) |
| } |
| |
| return args |
| } |
| |
| func (gcToolchain) asm(b *Builder, a *Action, sfiles []string) ([]string, error) { |
| p := a.Package |
| args := asmArgs(a, p) |
| |
| var ofiles []string |
| for _, sfile := range sfiles { |
| ofile := a.Objdir + sfile[:len(sfile)-len(".s")] + ".o" |
| ofiles = append(ofiles, ofile) |
| args1 := append(args, "-o", ofile, mkAbs(p.Dir, sfile)) |
| if err := b.run(a, p.Dir, p.ImportPath, nil, args1...); err != nil { |
| return nil, err |
| } |
| } |
| return ofiles, nil |
| } |
| |
| func (gcToolchain) symabis(b *Builder, a *Action, sfiles []string) (string, error) { |
| mkSymabis := func(p *load.Package, sfiles []string, path string) error { |
| args := asmArgs(a, p) |
| args = append(args, "-gensymabis", "-o", path) |
| for _, sfile := range sfiles { |
| if p.ImportPath == "runtime/cgo" && strings.HasPrefix(sfile, "gcc_") { |
| continue |
| } |
| args = append(args, mkAbs(p.Dir, sfile)) |
| } |
| |
| // Supply an empty go_asm.h as if the compiler had been run. |
| // -gensymabis parsing is lax enough that we don't need the |
| // actual definitions that would appear in go_asm.h. |
| if err := b.writeFile(a.Objdir+"go_asm.h", nil); err != nil { |
| return err |
| } |
| |
| return b.run(a, p.Dir, p.ImportPath, nil, args...) |
| } |
| |
| var symabis string // Only set if we actually create the file |
| p := a.Package |
| if len(sfiles) != 0 { |
| symabis = a.Objdir + "symabis" |
| if err := mkSymabis(p, sfiles, symabis); err != nil { |
| return "", err |
| } |
| } |
| |
| return symabis, nil |
| } |
| |
| // toolVerify checks that the command line args writes the same output file |
| // if run using newTool instead. |
| // Unused now but kept around for future use. |
| func toolVerify(a *Action, b *Builder, p *load.Package, newTool string, ofile string, args []interface{}) error { |
| newArgs := make([]interface{}, len(args)) |
| copy(newArgs, args) |
| newArgs[1] = base.Tool(newTool) |
| newArgs[3] = ofile + ".new" // x.6 becomes x.6.new |
| if err := b.run(a, p.Dir, p.ImportPath, nil, newArgs...); err != nil { |
| return err |
| } |
| data1, err := ioutil.ReadFile(ofile) |
| if err != nil { |
| return err |
| } |
| data2, err := ioutil.ReadFile(ofile + ".new") |
| if err != nil { |
| return err |
| } |
| if !bytes.Equal(data1, data2) { |
| return fmt.Errorf("%s and %s produced different output files:\n%s\n%s", filepath.Base(args[1].(string)), newTool, strings.Join(str.StringList(args...), " "), strings.Join(str.StringList(newArgs...), " ")) |
| } |
| os.Remove(ofile + ".new") |
| return nil |
| } |
| |
| func (gcToolchain) pack(b *Builder, a *Action, afile string, ofiles []string) error { |
| var absOfiles []string |
| for _, f := range ofiles { |
| absOfiles = append(absOfiles, mkAbs(a.Objdir, f)) |
| } |
| absAfile := mkAbs(a.Objdir, afile) |
| |
| // The archive file should have been created by the compiler. |
| // Since it used to not work that way, verify. |
| if !cfg.BuildN { |
| if _, err := os.Stat(absAfile); err != nil { |
| base.Fatalf("os.Stat of archive file failed: %v", err) |
| } |
| } |
| |
| p := a.Package |
| if cfg.BuildN || cfg.BuildX { |
| cmdline := str.StringList(base.Tool("pack"), "r", absAfile, absOfiles) |
| b.Showcmd(p.Dir, "%s # internal", joinUnambiguously(cmdline)) |
| } |
| if cfg.BuildN { |
| return nil |
| } |
| if err := packInternal(absAfile, absOfiles); err != nil { |
| b.showOutput(a, p.Dir, p.Desc(), err.Error()+"\n") |
| return errPrintedOutput |
| } |
| return nil |
| } |
| |
| func packInternal(afile string, ofiles []string) error { |
| dst, err := os.OpenFile(afile, os.O_WRONLY|os.O_APPEND, 0) |
| if err != nil { |
| return err |
| } |
| defer dst.Close() // only for error returns or panics |
| w := bufio.NewWriter(dst) |
| |
| for _, ofile := range ofiles { |
| src, err := os.Open(ofile) |
| if err != nil { |
| return err |
| } |
| fi, err := src.Stat() |
| if err != nil { |
| src.Close() |
| return err |
| } |
| // Note: Not using %-16.16s format because we care |
| // about bytes, not runes. |
| name := fi.Name() |
| if len(name) > 16 { |
| name = name[:16] |
| } else { |
| name += strings.Repeat(" ", 16-len(name)) |
| } |
| size := fi.Size() |
| fmt.Fprintf(w, "%s%-12d%-6d%-6d%-8o%-10d`\n", |
| name, 0, 0, 0, 0644, size) |
| n, err := io.Copy(w, src) |
| src.Close() |
| if err == nil && n < size { |
| err = io.ErrUnexpectedEOF |
| } else if err == nil && n > size { |
| err = fmt.Errorf("file larger than size reported by stat") |
| } |
| if err != nil { |
| return fmt.Errorf("copying %s to %s: %v", ofile, afile, err) |
| } |
| if size&1 != 0 { |
| w.WriteByte(0) |
| } |
| } |
| |
| if err := w.Flush(); err != nil { |
| return err |
| } |
| return dst.Close() |
| } |
| |
| // setextld sets the appropriate linker flags for the specified compiler. |
| func setextld(ldflags []string, compiler []string) []string { |
| for _, f := range ldflags { |
| if f == "-extld" || strings.HasPrefix(f, "-extld=") { |
| // don't override -extld if supplied |
| return ldflags |
| } |
| } |
| ldflags = append(ldflags, "-extld="+compiler[0]) |
| if len(compiler) > 1 { |
| extldflags := false |
| add := strings.Join(compiler[1:], " ") |
| for i, f := range ldflags { |
| if f == "-extldflags" && i+1 < len(ldflags) { |
| ldflags[i+1] = add + " " + ldflags[i+1] |
| extldflags = true |
| break |
| } else if strings.HasPrefix(f, "-extldflags=") { |
| ldflags[i] = "-extldflags=" + add + " " + ldflags[i][len("-extldflags="):] |
| extldflags = true |
| break |
| } |
| } |
| if !extldflags { |
| ldflags = append(ldflags, "-extldflags="+add) |
| } |
| } |
| return ldflags |
| } |
| |
| // pluginPath computes the package path for a plugin main package. |
| // |
| // This is typically the import path of the main package p, unless the |
| // plugin is being built directly from source files. In that case we |
| // combine the package build ID with the contents of the main package |
| // source files. This allows us to identify two different plugins |
| // built from two source files with the same name. |
| func pluginPath(a *Action) string { |
| p := a.Package |
| if p.ImportPath != "command-line-arguments" { |
| return p.ImportPath |
| } |
| h := sha1.New() |
| buildID := a.buildID |
| if a.Mode == "link" { |
| // For linking, use the main package's build ID instead of |
| // the binary's build ID, so it is the same hash used in |
| // compiling and linking. |
| // When compiling, we use actionID/actionID (instead of |
| // actionID/contentID) as a temporary build ID to compute |
| // the hash. Do the same here. (See buildid.go:useCache) |
| // The build ID matters because it affects the overall hash |
| // in the plugin's pseudo-import path returned below. |
| // We need to use the same import path when compiling and linking. |
| id := strings.Split(buildID, buildIDSeparator) |
| buildID = id[1] + buildIDSeparator + id[1] |
| } |
| fmt.Fprintf(h, "build ID: %s\n", buildID) |
| for _, file := range str.StringList(p.GoFiles, p.CgoFiles, p.SFiles) { |
| data, err := ioutil.ReadFile(filepath.Join(p.Dir, file)) |
| if err != nil { |
| base.Fatalf("go: %s", err) |
| } |
| h.Write(data) |
| } |
| return fmt.Sprintf("plugin/unnamed-%x", h.Sum(nil)) |
| } |
| |
| func (gcToolchain) ld(b *Builder, root *Action, out, importcfg, mainpkg string) error { |
| cxx := len(root.Package.CXXFiles) > 0 || len(root.Package.SwigCXXFiles) > 0 |
| for _, a := range root.Deps { |
| if a.Package != nil && (len(a.Package.CXXFiles) > 0 || len(a.Package.SwigCXXFiles) > 0) { |
| cxx = true |
| } |
| } |
| var ldflags []string |
| if cfg.BuildContext.InstallSuffix != "" { |
| ldflags = append(ldflags, "-installsuffix", cfg.BuildContext.InstallSuffix) |
| } |
| if root.Package.Internal.OmitDebug { |
| ldflags = append(ldflags, "-s", "-w") |
| } |
| if cfg.BuildBuildmode == "plugin" { |
| ldflags = append(ldflags, "-pluginpath", pluginPath(root)) |
| } |
| |
| // Store BuildID inside toolchain binaries as a unique identifier of the |
| // tool being run, for use by content-based staleness determination. |
| if root.Package.Goroot && strings.HasPrefix(root.Package.ImportPath, "cmd/") { |
| // External linking will include our build id in the external |
| // linker's build id, which will cause our build id to not |
| // match the next time the tool is built. |
| // Rely on the external build id instead. |
| if !sys.MustLinkExternal(cfg.Goos, cfg.Goarch) { |
| ldflags = append(ldflags, "-X=cmd/internal/objabi.buildID="+root.buildID) |
| } |
| } |
| |
| // If the user has not specified the -extld option, then specify the |
| // appropriate linker. In case of C++ code, use the compiler named |
| // by the CXX environment variable or defaultCXX if CXX is not set. |
| // Else, use the CC environment variable and defaultCC as fallback. |
| var compiler []string |
| if cxx { |
| compiler = envList("CXX", cfg.DefaultCXX(cfg.Goos, cfg.Goarch)) |
| } else { |
| compiler = envList("CC", cfg.DefaultCC(cfg.Goos, cfg.Goarch)) |
| } |
| ldflags = append(ldflags, "-buildmode="+ldBuildmode) |
| if root.buildID != "" { |
| ldflags = append(ldflags, "-buildid="+root.buildID) |
| } |
| ldflags = append(ldflags, forcedLdflags...) |
| ldflags = append(ldflags, root.Package.Internal.Ldflags...) |
| ldflags = setextld(ldflags, compiler) |
| |
| // On OS X when using external linking to build a shared library, |
| // the argument passed here to -o ends up recorded in the final |
| // shared library in the LC_ID_DYLIB load command. |
| // To avoid putting the temporary output directory name there |
| // (and making the resulting shared library useless), |
| // run the link in the output directory so that -o can name |
| // just the final path element. |
| // On Windows, DLL file name is recorded in PE file |
| // export section, so do like on OS X. |
| dir := "." |
| if (cfg.Goos == "darwin" || cfg.Goos == "windows") && cfg.BuildBuildmode == "c-shared" { |
| dir, out = filepath.Split(out) |
| } |
| |
| env := []string{} |
| if cfg.BuildTrimpath { |
| env = append(env, "GOROOT_FINAL=go") |
| } |
| return b.run(root, dir, root.Package.ImportPath, env, cfg.BuildToolexec, base.Tool("link"), "-o", out, "-importcfg", importcfg, ldflags, mainpkg) |
| } |
| |
| func (gcToolchain) ldShared(b *Builder, root *Action, toplevelactions []*Action, out, importcfg string, allactions []*Action) error { |
| ldflags := []string{"-installsuffix", cfg.BuildContext.InstallSuffix} |
| ldflags = append(ldflags, "-buildmode=shared") |
| ldflags = append(ldflags, forcedLdflags...) |
| ldflags = append(ldflags, root.Package.Internal.Ldflags...) |
| cxx := false |
| for _, a := range allactions { |
| if a.Package != nil && (len(a.Package.CXXFiles) > 0 || len(a.Package.SwigCXXFiles) > 0) { |
| cxx = true |
| } |
| } |
| // If the user has not specified the -extld option, then specify the |
| // appropriate linker. In case of C++ code, use the compiler named |
| // by the CXX environment variable or defaultCXX if CXX is not set. |
| // Else, use the CC environment variable and defaultCC as fallback. |
| var compiler []string |
| if cxx { |
| compiler = envList("CXX", cfg.DefaultCXX(cfg.Goos, cfg.Goarch)) |
| } else { |
| compiler = envList("CC", cfg.DefaultCC(cfg.Goos, cfg.Goarch)) |
| } |
| ldflags = setextld(ldflags, compiler) |
| for _, d := range toplevelactions { |
| if !strings.HasSuffix(d.Target, ".a") { // omit unsafe etc and actions for other shared libraries |
| continue |
| } |
| ldflags = append(ldflags, d.Package.ImportPath+"="+d.Target) |
| } |
| return b.run(root, ".", out, nil, cfg.BuildToolexec, base.Tool("link"), "-o", out, "-importcfg", importcfg, ldflags) |
| } |
| |
| func (gcToolchain) cc(b *Builder, a *Action, ofile, cfile string) error { |
| return fmt.Errorf("%s: C source files not supported without cgo", mkAbs(a.Package.Dir, cfile)) |
| } |