#!/usr/bin/env python2
-# Copyright (c) 2012-2013,2015 ARM Limited
+# Copyright (c) 2012-2013,2015-2016 ARM Limited
# All rights reserved
#
# The license below extends only to copyright in the software and shall
# be isa specific the method can verify the isa and use regexes to find the
# correct sections that need to be updated.
+# It is also possible to use this mechanism to revert prior tags. In this
+# case, implement a downgrade() method instead. Dependencies should still
+# work naturally - a tag depending on a tag with a downgrader means that it
+# insists on the other tag being removed and its downgrader executed before
+# its upgrader (or downgrader) can run. It is still the case that a tag
+# can only be used once.
+
+# Dependencies between tags are expressed by two variables at the top-level
+# of the upgrader script: "depends" can be either a string naming another
+# tag that it depends upon or a list of such strings; and "fwd_depends"
+# accepts the same datatypes but it reverses the sense of the dependency
+# arrow(s) -- it expresses that that tag depends upon the tag of the current
+# upgrader. This can be especially valuable when maintaining private
+# upgraders in private branches.
+
import ConfigParser
import glob, types, sys, os
class Upgrader:
tag_set = set()
+ untag_set = set() # tags to remove by downgrading
by_tag = {}
legacy = {}
def __init__(self, filename):
elif isinstance(self.depends, str):
self.depends = [self.depends]
- if not hasattr(self, 'upgrader'):
- print "Error: no upgrader method for", self.tag
+ if not isinstance(self.depends, list):
+ print "Error: 'depends' for %s is the wrong type" % self.tag
+ sys.exit(1)
+
+ if hasattr(self, 'fwd_depends'):
+ if isinstance(self.fwd_depends, str):
+ self.fwd_depends = [self.fwd_depends]
+ else:
+ self.fwd_depends = []
+
+ if not isinstance(self.fwd_depends, list):
+ print "Error: 'fwd_depends' for %s is the wrong type" % self.tag
sys.exit(1)
- elif not isinstance(self.upgrader, types.FunctionType):
- print "Error: 'upgrader' for %s is %s, not function", \
- self.tag, type(self)
+
+ if hasattr(self, 'upgrader'):
+ if not isinstance(self.upgrader, types.FunctionType):
+ print "Error: 'upgrader' for %s is %s, not function" \
+ % (self.tag, type(self))
+ sys.exit(1)
+ Upgrader.tag_set.add(self.tag)
+ elif hasattr(self, 'downgrader'):
+ if not isinstance(self.downgrader, types.FunctionType):
+ print "Error: 'downgrader' for %s is %s, not function" \
+ % (self.tag, type(self))
+ sys.exit(1)
+ Upgrader.untag_set.add(self.tag)
+ else:
+ print "Error: no upgrader or downgrader method for", self.tag
sys.exit(1)
if hasattr(self, 'legacy_version'):
Upgrader.legacy[self.legacy_version] = self
Upgrader.by_tag[self.tag] = self
- Upgrader.tag_set.add(self.tag)
def ready(self, tags):
for dep in self.depends:
return False
return True
- def upgrade(self, cpt):
- (self.upgrader)(cpt)
- verboseprint("applied upgrade for", self.tag)
+ def update(self, cpt, tags):
+ if hasattr(self, 'upgrader'):
+ self.upgrader(cpt)
+ tags.add(self.tag)
+ verboseprint("applied upgrade for", self.tag)
+ else:
+ self.downgrader(cpt)
+ tags.remove(self.tag)
+ verboseprint("applied downgrade for", self.tag)
@staticmethod
def get(tag):
Upgrader.legacy[i].depends = [Upgrader.legacy[i-1].tag]
i = i + 1
+ # resolve forward dependencies and audit normal dependencies
+ for tag, upg in Upgrader.by_tag.items():
+ for fd in upg.fwd_depends:
+ if fd not in Upgrader.by_tag:
+ print "Error: '%s' cannot (forward) depend on "\
+ "nonexistent tag '%s'" % (fd, tag)
+ sys.exit(1)
+ Upgrader.by_tag[fd].depends.append(tag)
+ for dep in upg.depends:
+ if dep not in Upgrader.by_tag:
+ print "Error: '%s' cannot depend on "\
+ "nonexistent tag '%s'" % (tag, dep)
+ sys.exit(1)
+
def process_file(path, **kwargs):
if not osp.isfile(path):
import errno
# If the current checkpoint has a tag we don't know about, we have
# a divergence that (in general) must be addressed by (e.g.) merging
# simulator support for its changes.
- unknown_tags = tags - Upgrader.tag_set
+ unknown_tags = tags - (Upgrader.tag_set | Upgrader.untag_set)
if unknown_tags:
print "warning: upgrade script does not recognize the following "\
"tags in this checkpoint:", ' '.join(unknown_tags)
- # Apply migrations for tags not in checkpoint, respecting dependences
- to_apply = Upgrader.tag_set - tags
+ # Apply migrations for tags not in checkpoint and tags present for which
+ # downgraders are present, respecting dependences
+ to_apply = (Upgrader.tag_set - tags) | (Upgrader.untag_set & tags)
while to_apply:
ready = set([ t for t in to_apply if Upgrader.get(t).ready(tags) ])
if not ready:
print "could not apply these upgrades:", ' '.join(to_apply)
- print "upgrade dependences impossible to resolve; aborting"
+ print "update dependences impossible to resolve; aborting"
exit(1)
for tag in ready:
- Upgrader.get(tag).upgrade(cpt)
- tags.add(tag)
+ Upgrader.get(tag).update(cpt, tags)
change = True
to_apply -= ready
projects / gem5.git / blobdiff