_XcodeVersion: return CLT version as appropriate

pylib/gyp/xcode_emulation.py

Index: pylib/gyp/xcode_emulation.py
diff --git a/pylib/gyp/xcode_emulation.py b/pylib/gyp/xcode_emulation.py
index e2ad93246b8d3630ebabcb7b029445b9920d8ec9..30f27d5832d99bd02ede773af5e59ed7c513b127 100644
--- a/pylib/gyp/xcode_emulation.py
+++ b/pylib/gyp/xcode_emulation.py
@@ -876,6 +876,27 @@ class XcodeSettings(object):
   def _BuildMachineOSBuild(self):
     return self._GetStdout(['sw_vers', '-buildVersion'])
 
+  # This method ported from the logic in Homebrew's CLT version check
+  def _CLTVersion(self):
+    # pkgutil output looks like
+    #   package-id: com.apple.pkg.CLTools_Executables
+    #   version: 5.0.1.0.1.1382131676
+    #   volume: /
+    #   location: /
+    #   install-time: 1382544035
+    #   groups: com.apple.FindSystemFiles.pkg-group com.apple.DevToolsBoth.pkg-group com.apple.DevToolsNonRelocatableShared.pkg-group
+    STANDALONE_PKG_ID = "com.apple.pkg.DeveloperToolsCLILeo"
+    FROM_XCODE_PKG_ID = "com.apple.pkg.DeveloperToolsCLI"
+    MAVERICKS_PKG_ID = "com.apple.pkg.CLTools_Executables"
+
+    regex = re.compile('version: (?P<version>.+)')
+    for key in [MAVERICKS_PKG_ID, STANDALONE_PKG_ID, FROM_XCODE_PKG_ID]:
+      try:
+        output = self._GetStdout(['/usr/sbin/pkgutil', '--pkg-info', key])
+        return re.search(regex, output).groupdict()['version']
+      except:
+        continue
+
   def _XcodeVersion(self):
     # `xcodebuild -version` output looks like
     #    Xcode 4.6.3
@@ -886,13 +907,30 @@ class XcodeSettings(object):
     #    BuildVersion: 10M2518
     # Convert that to '0463', '4H1503'.
     if len(XcodeSettings._xcode_version_cache) == 0:
-      version_list = self._GetStdout(['xcodebuild', '-version']).splitlines()
+      try:
+        version_list = self._GetStdout(['xcodebuild', '-version']).splitlines()
+        # In some circumstances xcodebuild exits 0 but doesn't return
+        # the right results; for example, a user on 10.7 or 10.8 with
+        # a bogus path set via xcode-select
+        # In that case this may be a CLT-only install so fall back to
+        # checking that version.
+        if len(version_list) < 2:
+          raise GypError, "xcodebuild returned unexpected results"
+      except:
+        version = self._CLTVersion()
+        if version:
+          version = re.match('(\d\.\d\.?\d*)', version).groups()[0]
+        else:
+          raise GypError, "No Xcode or CLT version detected!"
+        # The CLT has no build information, so we return an empty string.
+        version_list = [version, '']
       version = version_list[0]
       build = version_list[-1]
       # Be careful to convert "4.2" to "0420":
       version = version.split()[-1].replace('.', '')
       version = (version + '0' * (3 - len(version))).zfill(4)
-      build = build.split()[-1]
+      if build:
+        build = build.split()[-1]
       XcodeSettings._xcode_version_cache = (version, build)
     return XcodeSettings._xcode_version_cache
 
@@ -950,7 +988,11 @@ class XcodeSettings(object):
     default_sdk_root = XcodeSettings._sdk_root_cache.get(default_sdk_path)
     if default_sdk_root:
       return default_sdk_root
-    all_sdks = self._GetStdout(['xcodebuild', '-showsdks'])
+    try:
+      all_sdks = self._GetStdout(['xcodebuild', '-showsdks'])
+    except:
+      # If xcodebuild fails, there will be no valid SDKs
+      return ''
     for line in all_sdks.splitlines():
       items = line.split()
       if len(items) >= 3 and items[-2] == '-sdk':