Revert "Revert "Revert "Add path interposer"""

This reverts commit c59a92cb1a.

Reason for revert: tests are broken with long OUT_DIRs
They're directly calling net.Listen, and not using the fallback
for long socket names.

Change-Id: Id14cbd499fd9b36c6926b7552d3554340cb0916c

cmd/path_interposer/main_test.go

@@ -1,196 +0,0 @@
-// Copyright 2018 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.
-
-package main
-
-import (
-	"fmt"
-	"io/ioutil"
-	"os"
-	"path/filepath"
-	"testing"
-
-	"android/soong/ui/build/paths"
-)
-
-var tmpDir string
-var origPATH string
-
-func TestMain(m *testing.M) {
-	os.Exit(func() int {
-		var err error
-		tmpDir, err = ioutil.TempDir("", "interposer_test")
-		if err != nil {
-			panic(err)
-		}
-		defer os.RemoveAll(tmpDir)
-
-		origPATH = os.Getenv("PATH")
-		err = os.Setenv("PATH", "")
-		if err != nil {
-			panic(err)
-		}
-
-		return m.Run()
-	}())
-}
-
-func setup(t *testing.T) string {
-	f, err := ioutil.TempFile(tmpDir, "interposer")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer f.Close()
-
-	err = ioutil.WriteFile(f.Name()+"_origpath", []byte(origPATH), 0666)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return f.Name()
-}
-
-func TestInterposer(t *testing.T) {
-	interposer := setup(t)
-
-	logConfig := func(name string) paths.PathConfig {
-		if name == "true" {
-			return paths.PathConfig{
-				Log:   false,
-				Error: false,
-			}
-		} else if name == "path_interposer_test_not_allowed" {
-			return paths.PathConfig{
-				Log:   false,
-				Error: true,
-			}
-		}
-		return paths.PathConfig{
-			Log:   true,
-			Error: false,
-		}
-	}
-
-	testCases := []struct {
-		name string
-		args []string
-
-		exitCode int
-		err      error
-		logEntry string
-	}{
-		{
-			name: "direct call",
-			args: []string{interposer},
-
-			exitCode: 1,
-			err:      usage,
-		},
-		{
-			name: "relative call",
-			args: []string{filepath.Base(interposer)},
-
-			exitCode: 1,
-			err:      usage,
-		},
-		{
-			name: "true",
-			args: []string{"/my/path/true"},
-		},
-		{
-			name: "relative true",
-			args: []string{"true"},
-		},
-		{
-			name: "exit code",
-			args: []string{"bash", "-c", "exit 42"},
-
-			exitCode: 42,
-			logEntry: "bash",
-		},
-		{
-			name: "signal",
-			args: []string{"bash", "-c", "kill -9 $$"},
-
-			exitCode: 137,
-			logEntry: "bash",
-		},
-		{
-			name: "does not exist",
-			args: []string{"path_interposer_test_does_not_exist"},
-
-			exitCode: 1,
-			err:      fmt.Errorf(`exec: "path_interposer_test_does_not_exist": executable file not found in $PATH`),
-			logEntry: "path_interposer_test_does_not_exist",
-		},
-		{
-			name: "not allowed",
-			args: []string{"path_interposer_test_not_allowed"},
-
-			exitCode: 1,
-			err:      fmt.Errorf(`"path_interposer_test_not_allowed" is not allowed to be used. See https://android.googlesource.com/platform/build/+/master/Changes.md#PATH_Tools for more information.`),
-			logEntry: "path_interposer_test_not_allowed",
-		},
-	}
-
-	for _, testCase := range testCases {
-		t.Run(testCase.name, func(t *testing.T) {
-			logged := false
-			logFunc := func(logSocket string, entry *paths.LogEntry, done chan interface{}) {
-				defer close(done)
-
-				logged = true
-				if entry.Basename != testCase.logEntry {
-					t.Errorf("unexpected log entry:\nwant: %q\n got: %q", testCase.logEntry, entry.Basename)
-				}
-			}
-
-			exitCode, err := Main(ioutil.Discard, ioutil.Discard, interposer, testCase.args, mainOpts{
-				sendLog: logFunc,
-				config:  logConfig,
-			})
-
-			errstr := func(err error) string {
-				if err == nil {
-					return ""
-				}
-				return err.Error()
-			}
-			if errstr(testCase.err) != errstr(err) {
-				t.Errorf("unexpected error:\nwant: %v\n got: %v", testCase.err, err)
-			}
-			if testCase.exitCode != exitCode {
-				t.Errorf("expected exit code %d, got %d", testCase.exitCode, exitCode)
-			}
-			if !logged && testCase.logEntry != "" {
-				t.Errorf("no log entry, but expected %q", testCase.logEntry)
-			}
-		})
-	}
-}
-
-func TestMissingPath(t *testing.T) {
-	interposer := setup(t)
-	err := os.Remove(interposer + "_origpath")
-	if err != nil {
-		t.Fatalf("Failed to remove:", err)
-	}
-
-	exitCode, err := Main(ioutil.Discard, ioutil.Discard, interposer, []string{"true"}, mainOpts{})
-	if err != usage {
-		t.Errorf("Unexpected error:\n got: %v\nwant: %v", err, usage)
-	}
-	if exitCode != 1 {
-		t.Errorf("expected exit code %d, got %d", 1, exitCode)
-	}
-}