use.go

Documentation: cmd/go/internal/workcmd

     1  // Copyright 2021 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // go work use
     6  
     7  package workcmd
     8  
     9  import (
    10  	"context"
    11  	"fmt"
    12  	"io/fs"
    13  	"os"
    14  	"path/filepath"
    15  
    16  	"cmd/go/internal/base"
    17  	"cmd/go/internal/fsys"
    18  	"cmd/go/internal/gover"
    19  	"cmd/go/internal/modload"
    20  	"cmd/go/internal/str"
    21  	"cmd/go/internal/toolchain"
    22  
    23  	"golang.org/x/mod/modfile"
    24  )
    25  
    26  var cmdUse = &base.Command{
    27  	UsageLine: "go work use [-r] [moddirs]",
    28  	Short:     "add modules to workspace file",
    29  	Long: `Use provides a command-line interface for adding
    30  directories, optionally recursively, to a go.work file.
    31  
    32  A use directive will be added to the go.work file for each argument
    33  directory listed on the command line go.work file, if it exists,
    34  or removed from the go.work file if it does not exist.
    35  Use fails if any remaining use directives refer to modules that
    36  do not exist.
    37  
    38  Use updates the go line in go.work to specify a version at least as
    39  new as all the go lines in the used modules, both preexisting ones
    40  and newly added ones. With no arguments, this update is the only
    41  thing that go work use does.
    42  
    43  The -r flag searches recursively for modules in the argument
    44  directories, and the use command operates as if each of the directories
    45  were specified as arguments.
    46  
    47  
    48  
    49  See the workspaces reference at https://go.dev/ref/mod#workspaces
    50  for more information.
    51  `,
    52  }
    53  
    54  var useR = cmdUse.Flag.Bool("r", false, "")
    55  
    56  func init() {
    57  	cmdUse.Run = runUse // break init cycle
    58  
    59  	base.AddChdirFlag(&cmdUse.Flag)
    60  	base.AddModCommonFlags(&cmdUse.Flag)
    61  }
    62  
    63  func runUse(ctx context.Context, cmd *base.Command, args []string) {
    64  	modload.ForceUseModules = true
    65  	modload.InitWorkfile()
    66  	gowork := modload.WorkFilePath()
    67  	if gowork == "" {
    68  		base.Fatalf("go: no go.work file found\n\t(run 'go work init' first or specify path using GOWORK environment variable)")
    69  	}
    70  	wf, err := modload.ReadWorkFile(gowork)
    71  	if err != nil {
    72  		base.Fatal(err)
    73  	}
    74  	workUse(ctx, gowork, wf, args)
    75  	modload.WriteWorkFile(gowork, wf)
    76  }
    77  
    78  func workUse(ctx context.Context, gowork string, wf *modfile.WorkFile, args []string) {
    79  	workDir := filepath.Dir(gowork) // absolute, since gowork itself is absolute
    80  
    81  	haveDirs := make(map[string][]string) // absolute → original(s)
    82  	for _, use := range wf.Use {
    83  		var abs string
    84  		if filepath.IsAbs(use.Path) {
    85  			abs = filepath.Clean(use.Path)
    86  		} else {
    87  			abs = filepath.Join(workDir, use.Path)
    88  		}
    89  		haveDirs[abs] = append(haveDirs[abs], use.Path)
    90  	}
    91  
    92  	// keepDirs maps each absolute path to keep to the literal string to use for
    93  	// that path (either an absolute or a relative path), or the empty string if
    94  	// all entries for the absolute path should be removed.
    95  	keepDirs := make(map[string]string)
    96  
    97  	var sw toolchain.Switcher
    98  
    99  	// lookDir updates the entry in keepDirs for the directory dir,
   100  	// which is either absolute or relative to the current working directory
   101  	// (not necessarily the directory containing the workfile).
   102  	lookDir := func(dir string) {
   103  		absDir, dir := pathRel(workDir, dir)
   104  
   105  		file := base.ShortPath(filepath.Join(absDir, "go.mod"))
   106  		fi, err := fsys.Stat(file)
   107  		if err != nil {
   108  			if os.IsNotExist(err) {
   109  				keepDirs[absDir] = ""
   110  			} else {
   111  				sw.Error(err)
   112  			}
   113  			return
   114  		}
   115  
   116  		if !fi.Mode().IsRegular() {
   117  			sw.Error(fmt.Errorf("%v is not a regular file", file))
   118  			return
   119  		}
   120  
   121  		if dup := keepDirs[absDir]; dup != "" && dup != dir {
   122  			base.Errorf(`go: already added "%s" as "%s"`, dir, dup)
   123  		}
   124  		keepDirs[absDir] = dir
   125  	}
   126  
   127  	for _, useDir := range args {
   128  		absArg, _ := pathRel(workDir, useDir)
   129  
   130  		info, err := fsys.Stat(base.ShortPath(absArg))
   131  		if err != nil {
   132  			// Errors raised from os.Stat are formatted to be more user-friendly.
   133  			if os.IsNotExist(err) {
   134  				err = fmt.Errorf("directory %v does not exist", base.ShortPath(absArg))
   135  			}
   136  			sw.Error(err)
   137  			continue
   138  		} else if !info.IsDir() {
   139  			sw.Error(fmt.Errorf("%s is not a directory", base.ShortPath(absArg)))
   140  			continue
   141  		}
   142  
   143  		if !*useR {
   144  			lookDir(useDir)
   145  			continue
   146  		}
   147  
   148  		// Add or remove entries for any subdirectories that still exist.
   149  		// If the root itself is a symlink to a directory,
   150  		// we want to follow it (see https://go.dev/issue/50807).
   151  		// Add a trailing separator to force that to happen.
   152  		fsys.Walk(str.WithFilePathSeparator(useDir), func(path string, info fs.FileInfo, err error) error {
   153  			if err != nil {
   154  				return err
   155  			}
   156  
   157  			if !info.IsDir() {
   158  				if info.Mode()&fs.ModeSymlink != 0 {
   159  					if target, err := fsys.Stat(path); err == nil && target.IsDir() {
   160  						fmt.Fprintf(os.Stderr, "warning: ignoring symlink %s\n", base.ShortPath(path))
   161  					}
   162  				}
   163  				return nil
   164  			}
   165  			lookDir(path)
   166  			return nil
   167  		})
   168  
   169  		// Remove entries for subdirectories that no longer exist.
   170  		// Because they don't exist, they will be skipped by Walk.
   171  		for absDir := range haveDirs {
   172  			if str.HasFilePathPrefix(absDir, absArg) {
   173  				if _, ok := keepDirs[absDir]; !ok {
   174  					keepDirs[absDir] = "" // Mark for deletion.
   175  				}
   176  			}
   177  		}
   178  	}
   179  
   180  	// Update the work file.
   181  	for absDir, keepDir := range keepDirs {
   182  		nKept := 0
   183  		for _, dir := range haveDirs[absDir] {
   184  			if dir == keepDir { // (note that dir is always non-empty)
   185  				nKept++
   186  			} else {
   187  				wf.DropUse(dir)
   188  			}
   189  		}
   190  		if keepDir != "" && nKept != 1 {
   191  			// If we kept more than one copy, delete them all.
   192  			// We'll recreate a unique copy with AddUse.
   193  			if nKept > 1 {
   194  				wf.DropUse(keepDir)
   195  			}
   196  			wf.AddUse(keepDir, "")
   197  		}
   198  	}
   199  
   200  	// Read the Go versions from all the use entries, old and new (but not dropped).
   201  	goV := gover.FromGoWork(wf)
   202  	for _, use := range wf.Use {
   203  		if use.Path == "" { // deleted
   204  			continue
   205  		}
   206  		var abs string
   207  		if filepath.IsAbs(use.Path) {
   208  			abs = filepath.Clean(use.Path)
   209  		} else {
   210  			abs = filepath.Join(workDir, use.Path)
   211  		}
   212  		_, mf, err := modload.ReadModFile(base.ShortPath(filepath.Join(abs, "go.mod")), nil)
   213  		if err != nil {
   214  			sw.Error(err)
   215  			continue
   216  		}
   217  		goV = gover.Max(goV, gover.FromGoMod(mf))
   218  	}
   219  	sw.Switch(ctx)
   220  	base.ExitIfErrors()
   221  
   222  	modload.UpdateWorkGoVersion(wf, goV)
   223  	modload.UpdateWorkFile(wf)
   224  }
   225  
   226  // pathRel returns the absolute and canonical forms of dir for use in a
   227  // go.work file located in directory workDir.
   228  //
   229  // If dir is relative, it is interpreted relative to base.Cwd()
   230  // and its canonical form is relative to workDir if possible.
   231  // If dir is absolute or cannot be made relative to workDir,
   232  // its canonical form is absolute.
   233  //
   234  // Canonical absolute paths are clean.
   235  // Canonical relative paths are clean and slash-separated.
   236  func pathRel(workDir, dir string) (abs, canonical string) {
   237  	if filepath.IsAbs(dir) {
   238  		abs = filepath.Clean(dir)
   239  		return abs, abs
   240  	}
   241  
   242  	abs = filepath.Join(base.Cwd(), dir)
   243  	rel, err := filepath.Rel(workDir, abs)
   244  	if err != nil {
   245  		// The path can't be made relative to the go.work file,
   246  		// so it must be kept absolute instead.
   247  		return abs, abs
   248  	}
   249  
   250  	// Normalize relative paths to use slashes, so that checked-in go.work
   251  	// files with relative paths within the repo are platform-independent.
   252  	return abs, modload.ToDirectoryPath(rel)
   253  }
   254
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