Enables cross-compilation of the VM for ARM.

tools/build.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2012, 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.
 #
 
 import optparse
 import os
 import re
 import shutil
 import subprocess
 import sys
 import utils
 
 HOST_OS = utils.GuessOS()
 HOST_CPUS = utils.GuessCpus()
-armcompilerlocation = '/opt/codesourcery/arm-2009q1'
 SCRIPT_DIR = os.path.dirname(sys.argv[0])
 DART_ROOT = os.path.realpath(os.path.join(SCRIPT_DIR, '..'))
 THIRD_PARTY_ROOT = os.path.join(DART_ROOT, 'third_party')
 
+arm_cc_error = """
+Couldn't find the arm cross compiler.
+To make sure that you have the arm cross compilation tools installed, run:
+
+$ wget http://src.chromium.org/chrome/trunk/src/build/install-build-deps.sh
+OR
+$ svn co http://src.chromium.org/chrome/trunk/src/build; cd build
+Then,
+$ chmod u+x install-build-deps.sh
+$ ./install-build-deps.sh --arm --no-chromeos-fonts
+"""
+DEFAULT_ARM_CROSS_COMPILER_PATH = '/usr'
+
 def BuildOptions():
   result = optparse.OptionParser()
   result.add_option("-m", "--mode",
       help='Build variants (comma-separated).',
       metavar='[all,debug,release]',
       default='debug')
   result.add_option("-v", "--verbose",
       help='Verbose output.',
       default=False, action="store_true")
   result.add_option("-a", "--arch",
@@ skipping 67 matching lines @@
         return False
       if 'v8' in args:
         print "The v8 target is not supported for android builds."
         return False
   return True
 
 
 def SetTools(arch, toolchainprefix):
   toolsOverride = None
   if arch == 'arm' and toolchainprefix == None:
-    toolchainprefix = armcompilerlocation + "/bin/arm-none-linux-gnueabi"
+    toolchainprefix = DEFAULT_ARM_CROSS_COMPILER_PATH + "/bin/arm-linux-gnueabi"
   if toolchainprefix:
     toolsOverride = {
-      "CC"  :  toolchainprefix + "-gcc",
-      "CXX" :  toolchainprefix + "-g++",
-      "AR"  :  toolchainprefix + "-ar",
-      "LINK":  toolchainprefix + "-g++",
-      "NM"  :  toolchainprefix + "-nm",
+      "CC.target"  :  toolchainprefix + "-gcc",
+      "CXX.target" :  toolchainprefix + "-g++",
+      "AR.target"  :  toolchainprefix + "-ar",
+      "LINK.target":  toolchainprefix + "-g++",
+      "NM.target"  :  toolchainprefix + "-nm",
     }
   return toolsOverride
 
 
 def CheckDirExists(path, docstring):
   if not os.path.isdir(path):
     raise Exception('Could not find %s directory %s'
           % (docstring, path))
 
 
@@ skipping 276 matching lines @@
         if target_os == 'android':
           toolchainprefix = ('%s/i686-linux-android'
                               % os.environ['ANDROID_TOOLCHAIN'])
         toolsOverride = SetTools(arch, toolchainprefix)
         if toolsOverride:
           printToolOverrides = target_os != 'android'
           for k, v in toolsOverride.iteritems():
             args.append(  k + "=" + v)
             if printToolOverrides:
               print k + " = " + v
+          if not os.path.isfile(toolsOverride['CC.target']):
+            if arch == 'arm':
+              print arm_cc_error
+            else:
+              print "Couldn't find compiler: %s" % toolsOverride['CC.target']
+            return 1
+
 
         print ' '.join(args)
         process = None
         if filter_xcodebuild_output:
           process = subprocess.Popen(args,
                                      stdin=None,
                                      bufsize=1, # Line buffered.
                                      stdout=subprocess.PIPE,
                                      stderr=subprocess.STDOUT)
           FilterEmptyXcodebuildSections(process)
         else:
           process = subprocess.Popen(args, stdin=None)
         process.wait()
         if process.returncode != 0:
           print "BUILD FAILED"
           return 1
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(Main())