github.com/golangci/go-tools@v0.0.0-20190318060251-af6baa5dc196/cmd/rdeps/rdeps.go (about)

     1  // rdeps scans GOPATH for all reverse dependencies of a set of Go
     2  // packages.
     3  //
     4  // rdeps will not sort its output, and the order of the output is
     5  // undefined. Pipe its output through sort if you need stable output.
     6  package main
     7  
     8  import (
     9  	"bufio"
    10  	"flag"
    11  	"fmt"
    12  	"go/build"
    13  	"os"
    14  
    15  	"github.com/golangci/go-tools/version"
    16  
    17  	"github.com/kisielk/gotool"
    18  	"golang.org/x/tools/go/buildutil"
    19  	"golang.org/x/tools/refactor/importgraph"
    20  )
    21  
    22  func main() {
    23  	var tags buildutil.TagsFlag
    24  	flag.Var(&tags, "tags", "List of build tags")
    25  	stdin := flag.Bool("stdin", false, "Read packages from stdin instead of the command line")
    26  	recursive := flag.Bool("r", false, "Print reverse dependencies recursively")
    27  	printVersion := flag.Bool("version", false, "Print version and exit")
    28  	flag.Parse()
    29  
    30  	if *printVersion {
    31  		version.Print()
    32  		os.Exit(0)
    33  	}
    34  
    35  	ctx := build.Default
    36  	ctx.BuildTags = tags
    37  	var args []string
    38  	if *stdin {
    39  		s := bufio.NewScanner(os.Stdin)
    40  		for s.Scan() {
    41  			args = append(args, s.Text())
    42  		}
    43  	} else {
    44  		args = flag.Args()
    45  	}
    46  	if len(args) == 0 {
    47  		return
    48  	}
    49  	wd, err := os.Getwd()
    50  	if err != nil {
    51  		fmt.Fprintln(os.Stderr, err)
    52  		os.Exit(1)
    53  	}
    54  	pkgs := gotool.ImportPaths(args)
    55  	for i, pkg := range pkgs {
    56  		bpkg, err := ctx.Import(pkg, wd, build.FindOnly)
    57  		if err != nil {
    58  			continue
    59  		}
    60  		pkgs[i] = bpkg.ImportPath
    61  	}
    62  	_, reverse, errors := importgraph.Build(&ctx)
    63  	_ = errors
    64  
    65  	seen := map[string]bool{}
    66  	var printRDeps func(pkg string)
    67  	printRDeps = func(pkg string) {
    68  		for rdep := range reverse[pkg] {
    69  			if seen[rdep] {
    70  				continue
    71  			}
    72  			seen[rdep] = true
    73  			fmt.Println(rdep)
    74  			if *recursive {
    75  				printRDeps(rdep)
    76  			}
    77  		}
    78  	}
    79  
    80  	for _, pkg := range pkgs {
    81  		printRDeps(pkg)
    82  	}
    83  	for pkg, err := range errors {
    84  		fmt.Fprintf(os.Stderr, "error in package %s: %s\n", pkg, err)
    85  	}
    86  }