blob: bff298f78989c5ad3b09b98f9ca21316d3bb28d5 [file] [log] [blame]
// Copyright 2018 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.
// The gopackages command is a diagnostic tool that demonstrates
// how to use golang.org/x/tools/go/packages to load, parse,
// type-check, and print one or more Go packages.
// Its precise output is unspecified and may change.
package main
import (
"encoding/json"
"flag"
"fmt"
"go/types"
"log"
"os"
"runtime"
"runtime/pprof"
"runtime/trace"
"sort"
"strings"
"golang.org/x/tools/go/packages"
"golang.org/x/tools/go/types/typeutil"
)
// flags
var (
depsFlag = flag.Bool("deps", false, "show dependencies too")
testFlag = flag.Bool("test", false, "include any tests implied by the patterns")
mode = flag.String("mode", "imports", "mode (one of files, imports, types, syntax, allsyntax)")
private = flag.Bool("private", false, "show non-exported declarations too")
printJSON = flag.Bool("json", false, "print package in JSON form")
cpuprofile = flag.String("cpuprofile", "", "write CPU profile to this file")
memprofile = flag.String("memprofile", "", "write memory profile to this file")
traceFlag = flag.String("trace", "", "write trace log to this file")
buildFlags stringListValue
)
func init() {
flag.Var(&buildFlags, "buildflag", "pass argument to underlying build system (may be repeated)")
}
func usage() {
fmt.Fprintln(os.Stderr, `Usage: gopackages [-deps] [-cgo] [-mode=...] [-private] package...
The gopackages command loads, parses, type-checks,
and prints one or more Go packages.
Packages are specified using the notation of "go list",
or other underlying build system.
Flags:`)
flag.PrintDefaults()
}
func main() {
log.SetPrefix("gopackages: ")
log.SetFlags(0)
flag.Usage = usage
flag.Parse()
if len(flag.Args()) == 0 {
usage()
os.Exit(1)
}
if *cpuprofile != "" {
f, err := os.Create(*cpuprofile)
if err != nil {
log.Fatal(err)
}
if err := pprof.StartCPUProfile(f); err != nil {
log.Fatal(err)
}
// NB: profile won't be written in case of error.
defer pprof.StopCPUProfile()
}
if *traceFlag != "" {
f, err := os.Create(*traceFlag)
if err != nil {
log.Fatal(err)
}
if err := trace.Start(f); err != nil {
log.Fatal(err)
}
// NB: trace log won't be written in case of error.
defer func() {
trace.Stop()
log.Printf("To view the trace, run:\n$ go tool trace view %s", *traceFlag)
}()
}
if *memprofile != "" {
f, err := os.Create(*memprofile)
if err != nil {
log.Fatal(err)
}
// NB: memprofile won't be written in case of error.
defer func() {
runtime.GC() // get up-to-date statistics
if err := pprof.WriteHeapProfile(f); err != nil {
log.Fatalf("Writing memory profile: %v", err)
}
f.Close()
}()
}
// Load, parse, and type-check the packages named on the command line.
cfg := &packages.Config{
Mode: packages.LoadSyntax,
Tests: *testFlag,
BuildFlags: buildFlags,
}
// -mode flag
switch strings.ToLower(*mode) {
case "files":
cfg.Mode = packages.LoadFiles
case "imports":
cfg.Mode = packages.LoadImports
case "types":
cfg.Mode = packages.LoadTypes
case "syntax":
cfg.Mode = packages.LoadSyntax
case "allsyntax":
cfg.Mode = packages.LoadAllSyntax
default:
log.Fatalf("invalid mode: %s", *mode)
}
lpkgs, err := packages.Load(cfg, flag.Args()...)
if err != nil {
log.Fatal(err)
}
// -deps: print dependencies too.
if *depsFlag {
// We can't use packages.All because
// we need an ordered traversal.
var all []*packages.Package // postorder
seen := make(map[*packages.Package]bool)
var visit func(*packages.Package)
visit = func(lpkg *packages.Package) {
if !seen[lpkg] {
seen[lpkg] = true
// visit imports
var importPaths []string
for path := range lpkg.Imports {
importPaths = append(importPaths, path)
}
sort.Strings(importPaths) // for determinism
for _, path := range importPaths {
visit(lpkg.Imports[path])
}
all = append(all, lpkg)
}
}
for _, lpkg := range lpkgs {
visit(lpkg)
}
lpkgs = all
}
for _, lpkg := range lpkgs {
print(lpkg)
}
}
func print(lpkg *packages.Package) {
if *printJSON {
data, _ := json.MarshalIndent(lpkg, "", "\t")
os.Stdout.Write(data)
return
}
// title
var kind string
// TODO(matloob): If IsTest is added back print "test command" or
// "test package" for packages with IsTest == true.
if lpkg.Name == "main" {
kind += "command"
} else {
kind += "package"
}
fmt.Printf("Go %s %q:\n", kind, lpkg.ID) // unique ID
fmt.Printf("\tpackage %s\n", lpkg.Name)
// characterize type info
if lpkg.Types == nil {
fmt.Printf("\thas no exported type info\n")
} else if !lpkg.Types.Complete() {
fmt.Printf("\thas incomplete exported type info\n")
} else if len(lpkg.Syntax) == 0 {
fmt.Printf("\thas complete exported type info\n")
} else {
fmt.Printf("\thas complete exported type info and typed ASTs\n")
}
if lpkg.Types != nil && lpkg.IllTyped && len(lpkg.Errors) == 0 {
fmt.Printf("\thas an error among its dependencies\n")
}
// source files
for _, src := range lpkg.GoFiles {
fmt.Printf("\tfile %s\n", src)
}
// imports
var lines []string
for importPath, imp := range lpkg.Imports {
var line string
if imp.ID == importPath {
line = fmt.Sprintf("\timport %q", importPath)
} else {
line = fmt.Sprintf("\timport %q => %q", importPath, imp.ID)
}
lines = append(lines, line)
}
sort.Strings(lines)
for _, line := range lines {
fmt.Println(line)
}
// errors
for _, err := range lpkg.Errors {
fmt.Printf("\t%s\n", err)
}
// package members (TypeCheck or WholeProgram mode)
if lpkg.Types != nil {
qual := types.RelativeTo(lpkg.Types)
scope := lpkg.Types.Scope()
for _, name := range scope.Names() {
obj := scope.Lookup(name)
if !obj.Exported() && !*private {
continue // skip unexported names
}
fmt.Printf("\t%s\n", types.ObjectString(obj, qual))
if _, ok := obj.(*types.TypeName); ok {
for _, meth := range typeutil.IntuitiveMethodSet(obj.Type(), nil) {
if !meth.Obj().Exported() && !*private {
continue // skip unexported names
}
fmt.Printf("\t%s\n", types.SelectionString(meth, qual))
}
}
}
}
fmt.Println()
}
// stringListValue is a flag.Value that accumulates strings.
// e.g. --flag=one --flag=two would produce []string{"one", "two"}.
type stringListValue []string
func newStringListValue(val []string, p *[]string) *stringListValue {
*p = val
return (*stringListValue)(p)
}
func (ss *stringListValue) Get() interface{} { return []string(*ss) }
func (ss *stringListValue) String() string { return fmt.Sprintf("%q", *ss) }
func (ss *stringListValue) Set(s string) error { *ss = append(*ss, s); return nil }