Add support for building the Dart VM for Android OS.

tools/build.py

Index: tools/build.py
diff --git a/tools/build.py b/tools/build.py
index 1d1b8c805eb612d53389e92c512eeb5369442e54..480a4740c54835fd08738a866034503d7c36a75b 100755
--- a/tools/build.py
+++ b/tools/build.py
@@ -15,6 +15,9 @@ 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')
 
 def BuildOptions():
   result = optparse.OptionParser()
@@ -29,6 +32,9 @@ def BuildOptions():
       help='Target architectures (comma-separated).',
       metavar='[all,ia32,x64,simarm,arm]',
       default=utils.GuessArchitecture())
+  result.add_option("--os",
+      help='Target OS',
+      default=utils.GuessOS()),
   result.add_option("-j",
       help='The number of parallel jobs to run.',
       metavar=HOST_CPUS,
@@ -39,7 +45,7 @@ def BuildOptions():
   return result
 
 
-def ProcessOptions(options):
+def ProcessOptions(options, args):
   if options.arch == 'all':
     options.arch = 'ia32,x64'
   if options.mode == 'all':
@@ -54,19 +60,110 @@ def ProcessOptions(options):
     if not arch in ['ia32', 'x64', 'simarm', 'arm']:
       print "Unknown arch %s" % arch
       return False
+  if options.os != HOST_OS:
+    if options.os != 'android':
+      print "Unsupported target os %s" % options.os
+      return False
+    if not HOST_OS in ['linux']:
+      print ("Cross-compilation to %s is not supported on host os %s."
+             % (options.os, HOST_OS))
+      return False
+    if not arch in ['ia32']:
+      print ("Cross-compilation to %s is not supported for architecture %s."
+             % (options.os, arch))
+      return False
+    # We have not yet tweaked the v8 dart build to work with the Android
+    # NDK/SDK, so don't try to build it.
+    if args == []:
+      print "For android builds you must specify a target, such as 'dart'."
+      return False
+    if 'v8' in args:
+      print "The v8 target is not supported for android builds."
+      return False
   return True
 
 
-def setTools(arch):
-  if arch == 'arm':
+def SetTools(arch, toolchainprefix):
+  toolsOverride = None
+  if arch == 'arm' and toolchainprefix == None:
+    toolchainprefix = armcompilerlocation + "/bin/arm-none-linux-gnueabi"
+  if toolchainprefix:
     toolsOverride = {
-      "CC"  :  armcompilerlocation + "/bin/arm-none-linux-gnueabi-gcc",
-      "CXX" :  armcompilerlocation + "/bin/arm-none-linux-gnueabi-g++",
-      "AR"  :  armcompilerlocation + "/bin/arm-none-linux-gnueabi-ar",
-      "LINK":  armcompilerlocation + "/bin/arm-none-linux-gnueabi-g++",
-      "NM"  :  armcompilerlocation + "/bin/arm-none-linux-gnueabi-nm",
+      "CC"  :  toolchainprefix + "-gcc",
+      "CXX" :  toolchainprefix + "-g++",
+      "AR"  :  toolchainprefix + "-ar",
+      "LINK":  toolchainprefix + "-g++",
+      "NM"  :  toolchainprefix + "-nm",
     }
-    return toolsOverride
+  return toolsOverride
+
+
+def CheckDirExists(path, docstring):
+  if not os.path.isdir(path):
+    raise Exception('Could not find %s directory %s'
+          % (docstring, path))
+
+
+def SetCrossCompilationEnvironment(host_os, target_os, target_arch, old_path):
+  global THIRD_PARTY_ROOT
+  if host_os not in ['linux']:
+    raise Exception('Unsupported host os %s' % host_os)
+  if target_os not in ['android']:
+    raise Exception('Unsupported target os %s' % target_os)
+  if target_arch not in ['ia32']:
+    raise Exception('Unsupported target architecture %s' % target_arch)
+
+  CheckDirExists(THIRD_PARTY_ROOT, 'third party tools');
+  android_tools = os.path.join(THIRD_PARTY_ROOT, 'android_tools')
+  CheckDirExists(android_tools, 'Android tools')
+  android_ndk_root = os.path.join(android_tools, 'ndk')
+  CheckDirExists(android_ndk_root, 'Android NDK')
+  android_sdk_root = os.path.join(android_tools, 'sdk')
+  CheckDirExists(android_sdk_root, 'Android SDK')
+
+  os.environ['ANDROID_NDK_ROOT'] = android_ndk_root
+  os.environ['ANDROID_SDK_ROOT'] = android_sdk_root
+
+  toolchain_arch = 'x86-4.4.3'
+  toolchain_dir = 'linux-x86'
+  android_toolchain = os.path.join(android_ndk_root,
+      'toolchains', toolchain_arch,
+      'prebuilt', toolchain_dir, 'bin')
+  CheckDirExists(android_toolchain, 'Android toolchain')
+
+  os.environ['ANDROID_TOOLCHAIN'] = android_toolchain
+
+  android_sdk_version = 9
+
+  android_sdk_tools = os.path.join(android_sdk_root, 'tools')
+  CheckDirExists(android_sdk_tools, 'Android SDK tools')
+
+  android_sdk_platform_tools = os.path.join(android_sdk_root, 'platform-tools')
+  CheckDirExists(android_sdk_platform_tools, 'Android SDK platform tools')
+
+  pathList = [old_path,
+              android_ndk_root,
+              android_sdk_tools,
+              android_sdk_platform_tools,
+              # for Ninja - maybe don't need?
+              android_toolchain
+              ]
+  os.environ['PATH'] = ':'.join(pathList)
+
+  gypDefinesList = [
+    'target_arch=ia32',
+    'OS=%s' % target_os,
+    'android_build_type=0',
+    'host_os=%s' % host_os,
+    'linux_fpic=1',
+    'release_optimize=s',
+    'linux_use_tcmalloc=0',
+    'android_sdk=%s', os.path.join(android_sdk_root, 'platforms',
+        'android-%d' % android_sdk_version),
+    'android_sdk_tools=%s' % android_sdk_platform_tools
+    ]
+
+  os.environ['GYP_DEFINES'] = ' '.join(gypDefinesList)
 
 
 def Execute(args):
@@ -77,16 +174,41 @@ def Execute(args):
     raise Error(args[0] + " failed")
 
 
+def GClientRunHooks():
+  Execute(['gclient', 'runhooks'])
+
+
+def RunhooksIfNeeded(host_os, mode, arch, target_os):
+  build_root = utils.GetBuildRoot(host_os)
+  build_cookie_path = os.path.join(build_root, 'lastHooksTargetOS.txt')
+
+  old_target_os = None
+  try:
+    with open(build_cookie_path) as f:
+      old_target_os = f.read(1024)
+  except IOError as e:
+    pass
+  if target_os != old_target_os:
+    try:
+      os.mkdir(build_root)
+    except OSError as e:
+      pass
+    with open(build_cookie_path, 'w') as f:
+      f.write(target_os)
+    GClientRunHooks()
+
+
 def CurrentDirectoryBaseName():
   """Returns the name of the current directory"""
   return os.path.relpath(os.curdir, start=os.pardir)
 
+
 def Main():
   utils.ConfigureJava()
   # Parse the options.
   parser = BuildOptions()
   (options, args) = parser.parse_args()
-  if not ProcessOptions(options):
+  if not ProcessOptions(options, args):
     parser.print_help()
     return 1
   # Determine which targets to build. By default we build the "all" target.
@@ -97,6 +219,11 @@ def Main():
       target = 'all'
   else:
     target = args[0]
+
+  target_os = options.os
+
+  # Remember path
+  old_path = os.environ['PATH']
   # Build the targets for each requested configuration.
   for mode in options.mode:
     for arch in options.arch:
@@ -149,11 +276,23 @@ def Main():
 
         args += [target]
 
-      toolsOverride = setTools(arch)
+      if target_os != HOST_OS:
+        SetCrossCompilationEnvironment(
+            HOST_OS, target_os, arch, old_path)
+
+      RunhooksIfNeeded(HOST_OS, mode, arch, target_os)
+
+      toolchainprefix = None
+      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)
-          print k + " = " + v
+          if printToolOverrides:
+            print k + " = " + v
 
       print ' '.join(args)
       process = subprocess.Popen(args)