Convert soong_javac_filter to a wrapper
Piping the output of javac through a filter makes it hard to capture
the exit status. Convert it to a wrapper that executes javac and
propagates the exit status.
Bug: 36666657
Test: javac_wrapper_test
Change-Id: I9b56cc3794023aabc9328138a68830e26e980f97
diff --git a/cmd/javac_wrapper/javac_wrapper.go b/cmd/javac_wrapper/javac_wrapper.go
new file mode 100644
index 0000000..a323473
--- /dev/null
+++ b/cmd/javac_wrapper/javac_wrapper.go
@@ -0,0 +1,173 @@
+// Copyright 2017 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// soong_javac_wrapper expects a javac command line and argments, executes
+// it, and produces an ANSI colorized version of the output on stdout.
+//
+// It also hides the unhelpful and unhideable "warning there is a warning"
+// messages.
+package main
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+ "os"
+ "os/exec"
+ "regexp"
+ "syscall"
+)
+
+// Regular expressions are based on
+// https://chromium.googlesource.com/chromium/src/+/master/build/android/gyp/javac.py
+// Colors are based on clang's output
+var (
+ filelinePrefix = `^([-.\w/\\]+.java:[0-9]+: )`
+ warningRe = regexp.MustCompile(filelinePrefix + `?(warning:) .*$`)
+ errorRe = regexp.MustCompile(filelinePrefix + `(.*?:) .*$`)
+ markerRe = regexp.MustCompile(`()\s*(\^)\s*$`)
+
+ escape = "\x1b"
+ reset = escape + "[0m"
+ bold = escape + "[1m"
+ red = escape + "[31m"
+ green = escape + "[32m"
+ magenta = escape + "[35m"
+)
+
+func main() {
+ exitCode, err := Main(os.Args[0], os.Args[1:])
+ if err != nil {
+ fmt.Fprintln(os.Stderr, err.Error())
+ }
+ os.Exit(exitCode)
+}
+
+func Main(name string, args []string) (int, error) {
+ if len(args) < 1 {
+ return 1, fmt.Errorf("usage: %s javac ...", name)
+ }
+
+ pr, pw, err := os.Pipe()
+ if err != nil {
+ return 1, fmt.Errorf("creating output pipe: %s", err)
+ }
+
+ cmd := exec.Command(args[0], args[1:]...)
+ cmd.Stdin = os.Stdin
+ cmd.Stdout = pw
+ cmd.Stderr = pw
+ err = cmd.Start()
+ if err != nil {
+ return 1, fmt.Errorf("starting subprocess: %s", err)
+ }
+
+ pw.Close()
+
+ // Process subprocess stdout asynchronously
+ errCh := make(chan error)
+ go func() {
+ errCh <- process(pr, os.Stdout)
+ }()
+
+ // Wait for subprocess to finish
+ cmdErr := cmd.Wait()
+
+ // Wait for asynchronous stdout processing to finish
+ err = <-errCh
+
+ // Check for subprocess exit code
+ if cmdErr != nil {
+ if exitErr, ok := cmdErr.(*exec.ExitError); ok {
+ if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
+ if status.Exited() {
+ return status.ExitStatus(), nil
+ } else if status.Signaled() {
+ exitCode := 128 + int(status.Signal())
+ return exitCode, nil
+ } else {
+ return 1, exitErr
+ }
+ } else {
+ return 1, nil
+ }
+ }
+ }
+
+ if err != nil {
+ return 1, err
+ }
+
+ return 0, nil
+}
+
+func process(r io.Reader, w io.Writer) error {
+ scanner := bufio.NewScanner(r)
+ // Some javac wrappers output the entire list of java files being
+ // compiled on a single line, which can be very large, set the maximum
+ // buffer size to 2MB.
+ scanner.Buffer(nil, 2*1024*1024)
+ for scanner.Scan() {
+ processLine(w, scanner.Text())
+ }
+ err := scanner.Err()
+ if err != nil {
+ return fmt.Errorf("scanning input: %s", err)
+ }
+ return nil
+}
+
+func processLine(w io.Writer, line string) {
+ for _, f := range filters {
+ if f.MatchString(line) {
+ return
+ }
+ }
+ for _, p := range colorPatterns {
+ var matched bool
+ if line, matched = applyColor(line, p.color, p.re); matched {
+ break
+ }
+ }
+ fmt.Fprintln(w, line)
+}
+
+// If line matches re, make it bold and apply color to the first submatch
+// Returns line, modified if it matched, and true if it matched.
+func applyColor(line, color string, re *regexp.Regexp) (string, bool) {
+ if m := re.FindStringSubmatchIndex(line); m != nil {
+ tagStart, tagEnd := m[4], m[5]
+ line = bold + line[:tagStart] +
+ color + line[tagStart:tagEnd] + reset + bold +
+ line[tagEnd:] + reset
+ return line, true
+ }
+ return line, false
+}
+
+var colorPatterns = []struct {
+ re *regexp.Regexp
+ color string
+}{
+ {warningRe, magenta},
+ {errorRe, red},
+ {markerRe, green},
+}
+
+var filters = []*regexp.Regexp{
+ regexp.MustCompile(`Note: (Some input files|.*\.java) uses? or overrides? a deprecated API.`),
+ regexp.MustCompile(`Note: Recompile with -Xlint:deprecation for details.`),
+ regexp.MustCompile(`Note: (Some input files|.*\.java) uses? unchecked or unsafe operations.`),
+ regexp.MustCompile(`Note: Recompile with -Xlint:unchecked for details.`),
+}