1// Copyright 2017 Google Inc. All rights reserved.
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
15// soong_javac_wrapper expects a javac command line and argments, executes
16// it, and produces an ANSI colorized version of the output on stdout.
17//
18// It also hides the unhelpful and unhideable "warning there is a warning"
19// messages.
20//
21// Each javac build statement has an order-only dependency on the
22// soong_javac_wrapper tool, which means the javac command will not be rerun
23// if soong_javac_wrapper changes.  That means that soong_javac_wrapper must
24// not do anything that will affect the results of the build.
25package main
26
27import (
28	"bufio"
29	"fmt"
30	"io"
31	"os"
32	"os/exec"
33	"regexp"
34	"strconv"
35	"syscall"
36)
37
38// Regular expressions are based on
39// https://chromium.googlesource.com/chromium/src/+/master/build/android/gyp/javac.py
40// Colors are based on clang's output
41var (
42	filelinePrefix = `^([-.\w/\\]+.java:[0-9]+: )`
43	warningRe      = regexp.MustCompile(filelinePrefix + `?(warning:) .*$`)
44	errorRe        = regexp.MustCompile(filelinePrefix + `(.*?:) .*$`)
45	markerRe       = regexp.MustCompile(`()\s*(\^)\s*$`)
46
47	escape  = "\x1b"
48	reset   = escape + "[0m"
49	bold    = escape + "[1m"
50	red     = escape + "[31m"
51	green   = escape + "[32m"
52	magenta = escape + "[35m"
53)
54
55func main() {
56	exitCode, err := Main(os.Stdout, os.Args[0], os.Args[1:])
57	if err != nil {
58		fmt.Fprintln(os.Stderr, err.Error())
59	}
60	os.Exit(exitCode)
61}
62
63func Main(out io.Writer, name string, args []string) (int, error) {
64	if len(args) < 1 {
65		return 1, fmt.Errorf("usage: %s javac ...", name)
66	}
67
68	pr, pw, err := os.Pipe()
69	if err != nil {
70		return 1, fmt.Errorf("creating output pipe: %s", err)
71	}
72
73	cmd := exec.Command(args[0], args[1:]...)
74	cmd.Stdin = os.Stdin
75	cmd.Stdout = pw
76	cmd.Stderr = pw
77	err = cmd.Start()
78	if err != nil {
79		return 1, fmt.Errorf("starting subprocess: %s", err)
80	}
81
82	pw.Close()
83
84	proc := processor{}
85	// Process subprocess stdout asynchronously
86	errCh := make(chan error)
87	go func() {
88		errCh <- proc.process(pr, out)
89	}()
90
91	// Wait for subprocess to finish
92	cmdErr := cmd.Wait()
93
94	// Wait for asynchronous stdout processing to finish
95	err = <-errCh
96
97	// Check for subprocess exit code
98	if cmdErr != nil {
99		if exitErr, ok := cmdErr.(*exec.ExitError); ok {
100			if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
101				if status.Exited() {
102					return status.ExitStatus(), nil
103				} else if status.Signaled() {
104					exitCode := 128 + int(status.Signal())
105					return exitCode, nil
106				} else {
107					return 1, exitErr
108				}
109			} else {
110				return 1, nil
111			}
112		}
113	}
114
115	if err != nil {
116		return 1, err
117	}
118
119	return 0, nil
120}
121
122type processor struct {
123	silencedWarnings int
124}
125
126func (proc *processor) process(r io.Reader, w io.Writer) error {
127	scanner := bufio.NewScanner(r)
128	// Some javac wrappers output the entire list of java files being
129	// compiled on a single line, which can be very large, set the maximum
130	// buffer size to 2MB.
131	scanner.Buffer(nil, 2*1024*1024)
132	for scanner.Scan() {
133		proc.processLine(w, scanner.Text())
134	}
135	err := scanner.Err()
136	if err != nil {
137		return fmt.Errorf("scanning input: %s", err)
138	}
139	return nil
140}
141
142func (proc *processor) processLine(w io.Writer, line string) {
143	for _, f := range warningFilters {
144		if f.MatchString(line) {
145			proc.silencedWarnings++
146			return
147		}
148	}
149	for _, f := range filters {
150		if f.MatchString(line) {
151			return
152		}
153	}
154	if match := warningCount.FindStringSubmatch(line); match != nil {
155		c, err := strconv.Atoi(match[1])
156		if err == nil {
157			c -= proc.silencedWarnings
158			if c == 0 {
159				return
160			} else {
161				line = fmt.Sprintf("%d warning", c)
162				if c > 1 {
163					line += "s"
164				}
165			}
166		}
167	}
168	for _, p := range colorPatterns {
169		var matched bool
170		if line, matched = applyColor(line, p.color, p.re); matched {
171			break
172		}
173	}
174	fmt.Fprintln(w, line)
175}
176
177// If line matches re, make it bold and apply color to the first submatch
178// Returns line, modified if it matched, and true if it matched.
179func applyColor(line, color string, re *regexp.Regexp) (string, bool) {
180	if m := re.FindStringSubmatchIndex(line); m != nil {
181		tagStart, tagEnd := m[4], m[5]
182		line = bold + line[:tagStart] +
183			color + line[tagStart:tagEnd] + reset + bold +
184			line[tagEnd:] + reset
185		return line, true
186	}
187	return line, false
188}
189
190var colorPatterns = []struct {
191	re    *regexp.Regexp
192	color string
193}{
194	{warningRe, magenta},
195	{errorRe, red},
196	{markerRe, green},
197}
198
199var warningCount = regexp.MustCompile(`^([0-9]+) warning(s)?$`)
200
201var warningFilters = []*regexp.Regexp{
202	regexp.MustCompile(`bootstrap class path not set in conjunction with -source`),
203}
204
205var filters = []*regexp.Regexp{
206	regexp.MustCompile(`Note: (Some input files|.*\.java) uses? or overrides? a deprecated API.`),
207	regexp.MustCompile(`Note: Recompile with -Xlint:deprecation for details.`),
208	regexp.MustCompile(`Note: (Some input files|.*\.java) uses? unchecked or unsafe operations.`),
209	regexp.MustCompile(`Note: Recompile with -Xlint:unchecked for details.`),
210
211	regexp.MustCompile(`javadoc: warning - The old Doclet and Taglet APIs in the packages`),
212	regexp.MustCompile(`com.sun.javadoc, com.sun.tools.doclets and their implementations`),
213	regexp.MustCompile(`are planned to be removed in a future JDK release. These`),
214	regexp.MustCompile(`components have been superseded by the new APIs in jdk.javadoc.doclet.`),
215	regexp.MustCompile(`Users are strongly recommended to migrate to the new APIs.`),
216
217	regexp.MustCompile(`javadoc: option --boot-class-path not allowed with target 1.9`),
218}
219