improve xcode_emulation.py

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 ef5b46046ed965868eb3a8f23c4e8ea6d0ca68a0..ed5e27fa686dd256e4e047b9bd27adbaf71dbb3e 100644
--- a/pylib/gyp/xcode_emulation.py
+++ b/pylib/gyp/xcode_emulation.py
@@ -11,13 +11,16 @@ import gyp.common
 import os.path
 import re
 import shlex
+import subprocess
+import sys
+from gyp.common import GypError
 
 class XcodeSettings(object):
   """A class that understands the gyp 'xcode_settings' object."""
 
-  # Computed lazily by _GetSdkBaseDir(). Shared by all XcodeSettings, so cached
+  # Populated lazily by _SdkPath(). Shared by all XcodeSettings, so cached
   # at class-level for efficiency.
-  _sdk_base_dir = None
+  _sdk_path_cache = {}
 
   def __init__(self, spec):
     self.spec = spec
@@ -219,34 +222,34 @@ class XcodeSettings(object):
     else:
       return self._GetStandaloneBinaryPath()
 
-  def _GetSdkBaseDir(self):
-    """Returns the root of the 'Developer' directory. On Xcode 4.2 and prior,
-    this is usually just /Developer. Xcode 4.3 moved that folder into the Xcode
-    bundle."""
-    if not XcodeSettings._sdk_base_dir:
-      import subprocess
-      job = subprocess.Popen(['xcode-select', '-print-path'],
-                             stdout=subprocess.PIPE,
-                             stderr=subprocess.STDOUT)
-      out, err = job.communicate()
-      if job.returncode != 0:
-        print out
-        raise Exception('Error %d running xcode-select' % job.returncode)
-      # The Developer folder moved in Xcode 4.3.
-      xcode43_sdk_path = os.path.join(
-          out.rstrip(), 'Platforms/MacOSX.platform/Developer/SDKs')
-      if os.path.isdir(xcode43_sdk_path):
-        XcodeSettings._sdk_base_dir = xcode43_sdk_path
-      else:
-        XcodeSettings._sdk_base_dir = os.path.join(out.rstrip(), 'SDKs')
-    return XcodeSettings._sdk_base_dir
+  def _GetSdkVersionInfoItem(self, sdk, infoitem):
+    job = subprocess.Popen(['xcodebuild', '-version', '-sdk', sdk, infoitem],

[Nico, 2013/03/18 15:17:05]

As it turns out, this doesn't work with Xcode 4.2:

$ xcodebuild -version
Xcode 4.2
Build version 4C199
$ xcodebuild -version -sdk 10.6 
xcodebuild: error: SDK "10.6" cannot be located.

Yet:
$ ls /Developer/SDKs/MacOSX10.6.sdk/
Developer		Library			SDKSettings.plist	System			usr

[Nico, 2013/03/18 15:32:31]

Durr, it works if you say "macosx10.6" instead of "10.6". Sorry, ignore me.

[kal, 2013/03/18 15:32:32]

The SDK name is "macosx10.6". "10.6" is not a valid SDK name with any version of
Xcode.

[Nico, 2013/04/12 20:28:39]

Zombie thread: Why do you redirect stderr at all?

We just had some confusion because xcodebuild would error out:

https://gist.github.com/5374843

"""xcodebuild[39147:f07] Error loading
/Users/alexisme/Library/Developer/Xcode/Third-Party
Plug-ins/CodePilot2.xcplugin/Contents/MacOS/CodePilot2: 
dlopen(/Users/alexisme/Library/Developer/Xcode/Third-Party
Plug-ins/CodePilot2.xcplugin/Contents/MacOS/CodePilot2, 265): Symbol not found:
_IDEEditorDocumentDidChangeNotification
  Referenced from: /Users/alexisme/Library/Developer/Xcode/Third-Party
Plug-ins/CodePilot2.xcplugin/Contents/MacOS/CodePilot2
  Expected in: flat namespace
 in /Users/alexisme/Library/Developer/Xcode/Third-Party
Plug-ins/CodePilot2.xcplugin/Contents/MacOS/CodePilot2
2013-04-12 17:18:59.804 xcodebuild[39147:f07] WARNING: Failed to load plugin at:
/Users/alexisme/Library/Developer/Xcode/Third-Party
Plug-ins/CodePilot2.xcplugin, skipping.  Could not load bundle.
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk"""

…which silently got copied into the sdk version output, which then later caused
an assertion about a newline being in some env var string. What's the downside
of not redirecting stderr?

(Weird that this didn't cause a nonzero exit code though.)

+                           stdout=subprocess.PIPE,
+                           stderr=subprocess.STDOUT)
+    out = job.communicate()[0]
+    if job.returncode != 0:
+      sys.stderr.write(out + '\n')
+      raise GypError('Error %d running xcodebuild' % job.returncode)
+    return out.rstrip('\n')
 
   def _SdkPath(self):
-    sdk_root = self.GetPerTargetSetting('SDKROOT', default='macosx10.5')
-    if sdk_root.startswith('macosx'):
-      return os.path.join(self._GetSdkBaseDir(),
-                          'MacOSX' + sdk_root[len('macosx'):] + '.sdk')
-    return sdk_root
+    sdk_root = self.GetPerTargetSetting('SDKROOT', default='macosx')
+    if sdk_root not in XcodeSettings._sdk_path_cache:
+      XcodeSettings._sdk_path_cache[sdk_root] = self._GetSdkVersionInfoItem(
+          sdk_root, 'Path')
+    return XcodeSettings._sdk_path_cache[sdk_root]
+
+  def _AppendPlatformVersionMinFlags(self, lst):
+    self._Appendf(lst, 'MACOSX_DEPLOYMENT_TARGET', '-mmacosx-version-min=%s')
+    if 'IPHONEOS_DEPLOYMENT_TARGET' in self._Settings():
+      # TODO: Implement this better?

[Nico, 2013/03/13 17:45:25]

nit: remove this TODO, it's not actionable and mysterious

+      sdk_path_basename = os.path.basename(self._SdkPath())
+      if sdk_path_basename.lower().startswith('iphonesimulator'):
+        self._Appendf(lst, 'IPHONEOS_DEPLOYMENT_TARGET',
+                      '-mios-simulator-version-min=%s')
+      else:
+        self._Appendf(lst, 'IPHONEOS_DEPLOYMENT_TARGET',
+                      '-miphoneos-version-min=%s')
 
   def GetCflags(self, configname):
     """Returns flags that need to be added to .c, .cc, .m, and .mm
@@ -261,6 +264,9 @@ class XcodeSettings(object):
     if 'SDKROOT' in self._Settings():
       cflags.append('-isysroot %s' % sdk_root)
 
+    if self._Test('CLANG_WARN_CONSTANT_CONVERSION', 'YES', default='NO'):
+      cflags.append('-Wconstant-conversion')
+
     if self._Test('GCC_CHAR_IS_UNSIGNED_CHAR', 'YES', default='NO'):
       cflags.append('-funsigned-char')
 
@@ -301,7 +307,7 @@ class XcodeSettings(object):
     if self._Test('GCC_WARN_ABOUT_MISSING_NEWLINE', 'YES', default='NO'):
       cflags.append('-Wnewline-eof')
 
-    self._Appendf(cflags, 'MACOSX_DEPLOYMENT_TARGET', '-mmacosx-version-min=%s')
+    self._AppendPlatformVersionMinFlags(cflags)
 
     # TODO:
     if self._Test('COPY_PHASE_STRIP', 'YES', default='NO'):
@@ -354,6 +360,18 @@ class XcodeSettings(object):
     """Returns flags that need to be added to .cc, and .mm compilations."""
     self.configname = configname
     cflags_cc = []
+
+    clang_cxx_language_standard = self._Settings().get(
+        'CLANG_CXX_LANGUAGE_STANDARD')
+    if clang_cxx_language_standard == 'c++0x':
+      cflags_cc.append('-std=c++11')
+    elif clang_cxx_language_standard == 'gnu++0x':
+      cflags_cc.append('-std=gnu++11')
+    elif clang_cxx_language_standard:
+      cflags_cc.append('-std=%s' % clang_cxx_language_standard)
+
+    self._Appendf(cflags_cc, 'CLANG_CXX_LIBRARY', '-stdlib=%s')
+
     if self._Test('GCC_ENABLE_CPP_RTTI', 'NO', default='YES'):
       cflags_cc.append('-fno-rtti')
     if self._Test('GCC_ENABLE_CPP_EXCEPTIONS', 'NO', default='YES'):
@@ -524,8 +542,9 @@ class XcodeSettings(object):
         ldflags, 'DYLIB_COMPATIBILITY_VERSION', '-compatibility_version %s')
     self._Appendf(
         ldflags, 'DYLIB_CURRENT_VERSION', '-current_version %s')
-    self._Appendf(
-        ldflags, 'MACOSX_DEPLOYMENT_TARGET', '-mmacosx-version-min=%s')
+
+    self._AppendPlatformVersionMinFlags(ldflags)
+
     if 'SDKROOT' in self._Settings():
       ldflags.append('-isysroot ' + self._SdkPath())
 
@@ -1042,7 +1061,7 @@ def _TopologicallySortedEnvVarKeys(env):
     order.reverse()
     return order
   except gyp.common.CycleError, e:
-    raise Exception(
+    raise GypError(
         'Xcode environment variables are cyclically dependent: ' + str(e.nodes))