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-rwxr-xr-xutil/cpt_upgrader.py55
1 files changed, 38 insertions, 17 deletions
diff --git a/util/cpt_upgrader.py b/util/cpt_upgrader.py
index 5102fd5a2..b4e4beab2 100755
--- a/util/cpt_upgrader.py
+++ b/util/cpt_upgrader.py
@@ -1,6 +1,6 @@
#!/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
@@ -57,6 +57,13 @@
# 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.
+
import ConfigParser
import glob, types, sys, os
@@ -73,6 +80,7 @@ def verboseprint(*args):
class Upgrader:
tag_set = set()
+ untag_set = set() # tags to remove by downgrading
by_tag = {}
legacy = {}
def __init__(self, filename):
@@ -86,19 +94,26 @@ class Upgrader:
elif isinstance(self.depends, str):
self.depends = [self.depends]
- if not hasattr(self, 'upgrader'):
- print "Error: no upgrader method for", 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:
@@ -106,9 +121,15 @@ class Upgrader:
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):
@@ -173,23 +194,23 @@ def process_file(path, **kwargs):
# 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