1// Copyright 2021 Google LLC
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package main
16
17import (
18	"bytes"
19	"flag"
20	"fmt"
21	"io"
22	"io/fs"
23	"os"
24	"path/filepath"
25	"strings"
26
27	"android/soong/response"
28	"android/soong/tools/compliance"
29)
30
31var (
32	failNoneRequested = fmt.Errorf("\nNo license metadata files requested")
33	failNoLicenses    = fmt.Errorf("No licenses found")
34)
35
36type context struct {
37	stdout io.Writer
38	stderr io.Writer
39	rootFS fs.FS
40}
41
42func main() {
43	var expandedArgs []string
44	for _, arg := range os.Args[1:] {
45		if strings.HasPrefix(arg, "@") {
46			f, err := os.Open(strings.TrimPrefix(arg, "@"))
47			if err != nil {
48				fmt.Fprintln(os.Stderr, err.Error())
49				os.Exit(1)
50			}
51
52			respArgs, err := response.ReadRspFile(f)
53			f.Close()
54			if err != nil {
55				fmt.Fprintln(os.Stderr, err.Error())
56				os.Exit(1)
57			}
58			expandedArgs = append(expandedArgs, respArgs...)
59		} else {
60			expandedArgs = append(expandedArgs, arg)
61		}
62	}
63
64	flags := flag.NewFlagSet("flags", flag.ExitOnError)
65
66	outputFile := flags.String("o", "-", "Where to write the library list. (default stdout)")
67
68	flags.Usage = func() {
69		fmt.Fprintf(os.Stderr, `Usage: %s {options} file.meta_lic {file.meta_lic...}
70
71Outputs a list of libraries used in the shipped images.
72
73Options:
74`, filepath.Base(os.Args[0]))
75		flags.PrintDefaults()
76	}
77
78	err := flags.Parse(expandedArgs)
79	if err != nil {
80		flags.Usage()
81		fmt.Fprintf(os.Stderr, "%v\n", err)
82	}
83
84	// Must specify at least one root target.
85	if flags.NArg() == 0 {
86		flags.Usage()
87		os.Exit(2)
88	}
89
90	if len(*outputFile) == 0 {
91		flags.Usage()
92		fmt.Fprintf(os.Stderr, "must specify file for -o; use - for stdout\n")
93		os.Exit(2)
94	} else {
95		dir, err := filepath.Abs(filepath.Dir(*outputFile))
96		if err != nil {
97			fmt.Fprintf(os.Stderr, "cannot determine path to %q: %s\n", *outputFile, err)
98			os.Exit(1)
99		}
100		fi, err := os.Stat(dir)
101		if err != nil {
102			fmt.Fprintf(os.Stderr, "cannot read directory %q of %q: %s\n", dir, *outputFile, err)
103			os.Exit(1)
104		}
105		if !fi.IsDir() {
106			fmt.Fprintf(os.Stderr, "parent %q of %q is not a directory\n", dir, *outputFile)
107			os.Exit(1)
108		}
109	}
110
111	var ofile io.Writer
112	ofile = os.Stdout
113	if *outputFile != "-" {
114		ofile = &bytes.Buffer{}
115	}
116
117	ctx := &context{ofile, os.Stderr, compliance.FS}
118
119	err = shippedLibs(ctx, flags.Args()...)
120	if err != nil {
121		if err == failNoneRequested {
122			flags.Usage()
123		}
124		fmt.Fprintf(os.Stderr, "%s\n", err.Error())
125		os.Exit(1)
126	}
127	if *outputFile != "-" {
128		err := os.WriteFile(*outputFile, ofile.(*bytes.Buffer).Bytes(), 0666)
129		if err != nil {
130			fmt.Fprintf(os.Stderr, "could not write output to %q: %s\n", *outputFile, err)
131			os.Exit(1)
132		}
133	}
134	os.Exit(0)
135}
136
137// shippedLibs implements the shippedlibs utility.
138func shippedLibs(ctx *context, files ...string) error {
139	// Must be at least one root file.
140	if len(files) < 1 {
141		return failNoneRequested
142	}
143
144	// Read the license graph from the license metadata files (*.meta_lic).
145	licenseGraph, err := compliance.ReadLicenseGraph(ctx.rootFS, ctx.stderr, files)
146	if err != nil {
147		return fmt.Errorf("Unable to read license metadata file(s) %q: %v\n", files, err)
148	}
149	if licenseGraph == nil {
150		return failNoLicenses
151	}
152
153	// rs contains all notice resolutions.
154	rs := compliance.ResolveNotices(licenseGraph)
155
156	ni, err := compliance.IndexLicenseTexts(ctx.rootFS, licenseGraph, rs)
157	if err != nil {
158		return fmt.Errorf("Unable to read license text file(s) for %q: %v\n", files, err)
159	}
160
161	for lib := range ni.Libraries() {
162		fmt.Fprintln(ctx.stdout, lib)
163	}
164	return nil
165}
166