Create the SDK in a temporary directory and copy it as a final step.

tools/create_sdk.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2011, 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.
 #
-# A script which will be invoked from gyp to create an SDK. The SDK will be
-# used either from the command-line or from the editor. Top structure is
+# A script which will be invoked from gyp to create an SDK. 
+#
+# Usage: create_sdk.py sdk_directory
+#
+# The SDK will be used either from the command-line or from the editor. 
+# Top structure is
 # 
 # ..sdk/
 # ....bin/
 # ......dart or dart.exe (executable)
 # ......frogc.dart
 # ......frogsh (coming later)
 # ....lib/
 # ......builtin/
 # ........builtin_runtime.dart
 # ........runtime/
 # ......core/
 # ........core_{compiler, frog, runtime}.dart
 # ........{compiler, frog, runtime}/ 
 # ......coreimpl/
 # ........coreimpl_{compiler, frog, runtime}.dart
 # ........{compiler, frog, runtime}/ 
 # ......dom/
 # ........dom.dart
 # ......frog/
 # ......html/ 
 # ........html.dart
 # ......htmlimpl/ 
 # ........htmlimpl.dart
 # ......json/
 # ........json_{compiler, frog}.dart
 # ........{compiler, frog}/
 # ......(more will come here - io, etc)
-# ....tools/
+# ....util/
 # ......dartdoc/
 # ......(more will come here)
 
 
 
 import os
 import re
 import sys
+import tempfile
 import utils
 
 from os.path import dirname, join, realpath, exists, isdir
-from shutil import copyfile, copymode, copytree, ignore_patterns, rmtree
+from shutil import copyfile, copymode, copytree, ignore_patterns, rmtree, move
 
 def Main(argv):
   # Pull in all of the gpyi files which will be munged into the sdk.
   builtin_runtime_sources = \
     (eval(open("runtime/bin/builtin_sources.gypi").read()))['sources']
   corelib_sources = \
     (eval(open("corelib/src/corelib_sources.gypi").read()))['sources']
   corelib_frog_sources = \
     (eval(open("frog/lib/frog_corelib_sources.gypi").read()))['sources']
   corelib_runtime_sources = \
     (eval(open("runtime/lib/lib_sources.gypi").read()))['sources']
   corelib_compiler_sources =  \
     (eval(open("compiler/compiler_corelib_sources.gypi").read())) \
     ['variables']['compiler_corelib_resources']
   coreimpl_sources = \
     (eval(open("corelib/src/implementation/corelib_impl_sources.gypi").read()))\
     ['sources']
   coreimpl_frog_sources = \
     (eval(open("frog/lib/frog_coreimpl_sources.gypi").read()))['sources']
   coreimpl_runtime_sources = \
     (eval(open("runtime/lib/lib_impl_sources.gypi").read()))['sources']
   json_compiler_sources = \
     (eval(open("compiler/jsonlib_sources.gypi").read())) \
     ['variables']['jsonlib_resources']
   json_frog_sources = \
     (eval(open("frog/lib/frog_json_sources.gypi").read()))['sources']
 
   HOME = dirname(dirname(realpath(__file__)))
 
+  SDK_tmp = tempfile.mkdtemp()
   SDK = argv[1]
 
   # TODO(dgrove) - deal with architectures that are not ia32.
   if (os.path.basename(os.path.dirname(SDK)) != 
       utils.GetBuildConf('release', 'ia32')):
     print "SDK is not built in Debug mode."
     if not os.path.exists(SDK):
       # leave empty dir behind
       os.makedirs(SDK)
     exit(0)
 
   if exists(SDK):
     rmtree(SDK)
 
   # Create and populate sdk/bin.
-  BIN = join(SDK, 'bin')
+  BIN = join(SDK_tmp, 'bin')
   os.makedirs(BIN)
 
   # Copy the Dart VM binary into sdk/bin.
   # TODO(dgrove) - deal with architectures that are not ia32.
   build_dir = utils.GetBuildRoot(utils.GuessOS(), 'release', 'ia32')
   if utils.GuessOS() == 'win32':
     dart_src_binary = join(join(HOME, build_dir), 'dart.exe')
     dart_dest_binary = join(BIN, 'dart.exe')
   else:
     dart_src_binary = join(join(HOME, build_dir), 'dart')
@@ skipping 10 matching lines @@
   frogc_dest.write(
     re.sub("#import\('", "#import('../lib/frog/", frogc_contents))
   frogc_dest.close()
 
   # TODO(dgrove): copy and fix up frog.dart, minfrogc.dart.
 
   #
   # Create and populate sdk/lib.
   #
 
-  LIB = join(SDK, 'lib')
+  LIB = join(SDK_tmp, 'lib')
   os.makedirs(LIB)
   corelib_dest_dir = join(LIB, 'core')
   os.makedirs(corelib_dest_dir)
   os.makedirs(join(corelib_dest_dir, 'compiler'))
   os.makedirs(join(corelib_dest_dir, 'frog'))
   os.makedirs(join(corelib_dest_dir, 'runtime'))
 
   coreimpl_dest_dir = join(LIB, 'coreimpl')
   os.makedirs(coreimpl_dest_dir)
   os.makedirs(join(coreimpl_dest_dir, 'compiler'))
@@ skipping 209 matching lines @@
     dest_file.write('#source("runtime/' + filename + '");\n')
   for filename in coreimpl_runtime_sources:
     if filename.endswith('.dart'):
       dest_file.write('#source("runtime/' + filename + '");\n')
   dest_file.close()
 
   # TODO(dgrove) - create lib/coreimpl/coreimpl_compiler.dart .
 
   # Create and copy tools.
 
-  UTIL = join(SDK, 'tools')
+  UTIL = join(SDK_tmp, 'util')
   os.makedirs(UTIL)
 
   copytree(join(HOME, 'utils', 'dartdoc'), join(UTIL, 'dartdoc'), 
            ignore=ignore_patterns('.svn'))
 
+  copytree(SDK_tmp, SDK)

[ahe, 2011/12/07 11:23:29]

Have you considered this approach (in shell script pseudo code):

rm -rf $SDK
rm -rf ${SDK}.tmp
mkdir ${SDK}.tmp
put everything in ${SDK}.tmp
mv ${SDK}.tmp $SDK

The downside to the current approach is that it is twice as slow.

[ahe, 2011/12/07 11:25:11]

Actually, there is another downside to the current approach. You cannot
interrupt the build safely. If I hit Ctrl-C while copytree is running, I get a
broken build.

+  rmtree(SDK_tmp)
+
 if __name__ == '__main__':
   sys.exit(Main(sys.argv))