Add recursion=n syntax to DEPS files.

gclient.py

Index: gclient.py
diff --git a/gclient.py b/gclient.py
index 9065952bdfd959d56b56dbdf1be77ebfc3dd1c61..7d282f2ca266e4d93c574cbef50e3e1cf3463889 100644
--- a/gclient.py
+++ b/gclient.py
@@ -168,6 +168,14 @@ class DependencySettings(GClientKeywords):
     # recursion limit and controls gclient's behavior so it does not misbehave.
     self._managed = managed
     self._should_process = should_process
+    # This is a mutable value that overrides the normal recursion limit for this
+    # dependency.  It is read from the actual DEPS file so cannot be set on
+    # class instantiation.
+    # This is currently only supported for top-level deps because gclient does

[M-A Ruel, 2012/10/17 11:08:25]

Interesting note. I would have said it's just fine; when the same exact
dependency is fetched twice, it's creating two independent Dependency instances.

[Isaac (away), 2012/10/17 16:24:02]

Here's an example of what I'm concerned about.  Maybe it will already work, not
sure!

.gclient{
dep1,
dep2,
}
dep1{deps={dep3}}
dep2{deps={dep3}, recursion=2}
dep3{deps={dep4}}

When we process .gclient -> dep1 -> dep3, we are at recursion limit, so do not
process dep4.  When we process .gclient -> dep2, we do not add dep3 a second
time.

dep4 should have be added but will not be.

[M-A Ruel, 2012/10/17 16:57:34]

I'm pretty sure it's handled correctly. "deps3" is loaded two times in the graph
as separate instances. Technically I'd like to see this tested but I won't
require it.

still lgtm.

+    # not have logic for conflict handling where the same dep is specified
+    # twice, one in a non-overriden subtree and one in an overriden subtree.
+    # TODO(ilevy) Add recursion override support for non-top-level deps.
+    self.recursion_override = None
 
     # These are only set in .gclient and not in DEPS files.
     self._custom_vars = custom_vars or {}
@@ -231,6 +239,8 @@ class DependencySettings(GClientKeywords):
   @property
   def recursion_limit(self):
     """Returns > 0 if this dependency is not too recursed to be processed."""
+    if self.recursion_override is not None:
+      return self.recursion_override
     return max(self.parent.recursion_limit - 1, 0)
 
   def get_custom_deps(self, name, url):
@@ -445,6 +455,10 @@ class Dependency(gclient_utils.WorkItem, DependencySettings):
       except SyntaxError, e:
         gclient_utils.SyntaxErrorToError(filepath, e)
     deps = local_scope.get('deps', {})
+    if 'recursion' in local_scope:

[M-A Ruel, 2012/10/17 11:08:25]

No need to "if" that. local_scope.get('recursion') returns None if the value
doesn't exist, and None means that the value is not overriden.

[Isaac (away), 2012/10/17 16:24:02]

I want the if for the logging line, though.

+      self.recursion_override = local_scope.get('recursion')
+      logging.warning(
+          'Setting %s recursion to %d.', self.name, self.recursion_limit)
     # load os specific dependencies if defined.  these dependencies may
     # override or extend the values defined by the 'deps' member.
     if 'deps_os' in local_scope: