mac ninja/make: Do topological sort only once instead of at each access.

pylib/gyp/xcode_emulation.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 This module contains classes that help to emulate xcodebuild behavior on top of
 other build systems, such as make and ninja.
 """
 
 import gyp.common
@@ skipping 865 matching lines @@
         'INFOPLIST_PREPROCESSOR_DEFINITIONS', default=''))
   else:
     defines = []
 
   dest_plist = os.path.join(product_dir, xcode_settings.GetBundlePlistPath())
   extra_env = xcode_settings.GetPerTargetSettings()
 
   return info_plist, dest_plist, defines, extra_env
 
 
-def GetXcodeEnv(xcode_settings, built_products_dir, srcroot, configuration,
+def _GetXcodeEnv(xcode_settings, built_products_dir, srcroot, configuration,
                 additional_settings=None):
   """Return the environment variables that Xcode would set. See
   http://developer.apple.com/library/mac/#documentation/DeveloperTools/Reference/XcodeBuildSettingRef/1-Build_Setting_Reference/build_setting_ref.html#//apple_ref/doc/uid/TP40003931-CH3-SW153
   for a full list.
 
   Args:
       xcode_settings: An XcodeSettings object. If this is None, this function
           returns an empty dict.
       built_products_dir: Absolute path to the built products dir.
       srcroot: Absolute path to the source root.
@@ skipping 71 matching lines @@
   for match in matches:
     to_replace, variable = match
     assert '$(' not in match, '$($(FOO)) variables not supported: ' + match
     str = str.replace(to_replace, '${' + variable + '}')
 
   return str
 
 
 def ExpandEnvVars(string, expansions):
   """Expands ${VARIABLES}, $(VARIABLES), and $VARIABLES in string per the
-  expansions dict. If the variable expands to something that references
+  expansions list. If the variable expands to something that references
   another variable, this variable is expanded as well if it's in env --
   until no variables present in env are left."""
-  for k in reversed(TopologicallySortedEnvVarKeys(expansions)):
-    string = string.replace('${' + k + '}', expansions[k])
-    string = string.replace('$(' + k + ')', expansions[k])
-    string = string.replace('$' + k, expansions[k])
+  for k, v in reversed(expansions):
+    string = string.replace('${' + k + '}', v)
+    string = string.replace('$(' + k + ')', v)
+    string = string.replace('$' + k, v)
   return string
 
 
-def TopologicallySortedEnvVarKeys(env):
+def _TopologicallySortedEnvVarKeys(env):
   """Takes a dict |env| whose values are strings that can refer to other keys,
   for example env['foo'] = '$(bar) and $(baz)'. Returns a list L of all keys of
   env such that key2 is after key1 in L if env[key2] refers to env[key1].
 
   Throws an Exception in case of dependency cycles.
   """
   # Since environment variables can refer to other variables, the evaluation
   # order is important. Below is the logic to compute the dependency graph
   # and sort it.
   regex = re.compile(r'\$\{([a-zA-Z0-9\-_]+)\}')
   def GetEdges(node):
     # Use a definition of edges such that user_of_variable -> used_varible.
     # This happens to be easier in this case, since a variable's
     # definition contains all variables it references in a single string.
     # We can then reverse the result of the topological sort at the end.
     # Since: reverse(topsort(DAG)) = topsort(reverse_edges(DAG))
     matches = set([v for v in regex.findall(env[node]) if v in env])
     for dependee in matches:
       assert '${' not in dependee, 'Nested variables not supported: ' + dependee
     return matches
 
   try:
     # Topologically sort, and then reverse, because we used an edge definition
     # that's inverted from the expected result of this function (see comment
     # above).
     order = gyp.common.TopologicallySorted(env.keys(), GetEdges)
     order.reverse()
     return order
-  except CycleError, e:
+  except gyp.common.CycleError, e:

[scottmg, 2012/05/28 20:53:29]

did this just not work before?

[Nico, 2012/05/28 20:57:18]

Apparently.

Maybe the function had no callers in this file and in other modules CycleError
was already imported *handwave* No idea really, but python said "Don't know
CycleError" and I complied.

     raise Exception(
         'Xcode environment variables are cyclically dependent: ' + str(e.nodes))
 
 
+def GetSortedXcodeEnv(xcode_settings, built_products_dir, srcroot,
+                      configuration, additional_settings=None):
+  env = _GetXcodeEnv(xcode_settings, built_products_dir, srcroot, configuration,
+                    additional_settings)
+  return [(key, env[key]) for key in _TopologicallySortedEnvVarKeys(env)]
+
+
 def GetSpecPostbuildCommands(spec, quiet=False):
   """Returns the list of postbuilds explicitly defined on |spec|, in a form
   executable by a shell."""
   postbuilds = []
   for postbuild in spec.get('postbuilds', []):
     if not quiet:
       postbuilds.append('echo POSTBUILD\\(%s\\) %s' % (
             spec['target_name'], postbuild['postbuild_name']))
     postbuilds.append(gyp.common.EncodePOSIXShellList(postbuild['action']))
   return postbuilds