Support directories other than "web" in pub build.

sdk/lib/_internal/pub/lib/src/io.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Helper functionality to make working with IO easier.
 library pub.io;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
 import 'package:http/http.dart' show ByteStream;
 import 'package:stack_trace/stack_trace.dart';
 
+import 'exit_codes.dart' as exit_codes;
 import 'error_group.dart';
 import 'log.dart' as log;
 import 'pool.dart';
 import 'sdk.dart' as sdk;
 import 'utils.dart';
 
 export 'package:http/http.dart' show ByteStream;
 
 /// The pool used for restricting access to asynchronous operations that consume
 /// file descriptors.
@@ skipping 693 matching lines @@
     // process.exitCode, and we don't want them being top-levelled by
     // std{out,err}Sink.
     store(process.stdout.handleError((_) {}), stdout, closeSink: false);
     store(process.stderr.handleError((_) {}), stderr, closeSink: false);
     return Future.wait([
       store(stream, process.stdin),
       process.exitCode
     ]);
   }).then((results) {
     var exitCode = results[1];
-    if (exitCode != 0) {
+    if (exitCode != exit_codes.SUCCESS) {
       throw new Exception("Failed to extract .tar.gz stream to $destination "
           "(exit code $exitCode).");
     }
     log.fine("Extracted .tar.gz stream to $destination. Exit code $exitCode.");
   });
 }
 
 String get pathTo7zip {
   if (runningFromSdk) return resourcePath(path.join('7zip', '7za.exe'));
   return path.join(repoRoot, 'third_party', '7zip', '7za.exe');
@@ skipping 11 matching lines @@
   return withTempDir((tempDir) {
     // Write the archive to a temp file.
     var dataFile = path.join(tempDir, 'data.tar.gz');
     return createFileFromStream(stream, dataFile).then((_) {
       // 7zip can't unarchive from gzip -> tar -> destination all in one step
       // first we un-gzip it to a tar file.
       // Note: Setting the working directory instead of passing in a full file
       // path because 7zip says "A full path is not allowed here."
       return runProcess(pathTo7zip, ['e', 'data.tar.gz'], workingDir: tempDir);
     }).then((result) {
-      if (result.exitCode != 0) {
+      if (result.exitCode != exit_codes.SUCCESS) {
         throw new Exception('Could not un-gzip (exit code ${result.exitCode}). '
                 'Error:\n'
             '${result.stdout.join("\n")}\n'
             '${result.stderr.join("\n")}');
       }
 
       // Find the tar file we just created since we don't know its name.
       var tarFile = listDir(tempDir).firstWhere(
           (file) => path.extension(file) == '.tar',
           orElse: () {
         throw new FormatException('The gzip file did not contain a tar file.');
       });
 
       // Untar the archive into the destination directory.
       return runProcess(pathTo7zip, ['x', tarFile], workingDir: destination);
     }).then((result) {
-      if (result.exitCode != 0) {
+      if (result.exitCode != exit_codes.SUCCESS) {
         throw new Exception('Could not un-tar (exit code ${result.exitCode}). '
                 'Error:\n'
             '${result.stdout.join("\n")}\n'
             '${result.stderr.join("\n")}');
       }
       return true;
     });
   });
 }
 
@@ skipping 58 matching lines @@
 }
 
 /// Contains the results of invoking a [Process] and waiting for it to complete.
 class PubProcessResult {
   final List<String> stdout;
   final List<String> stderr;
   final int exitCode;
 
   const PubProcessResult(this.stdout, this.stderr, this.exitCode);
 
-  bool get success => exitCode == 0;
+  bool get success => exitCode == exit_codes.SUCCESS;
 }
 
 /// Gets a [Uri] for [uri], which can either already be one, or be a [String].
 Uri _getUri(uri) {
   if (uri is Uri) return uri;
   return Uri.parse(uri);
 }