tests/hghave

revset: add helper to build balanced addsets from chained 'or' operations

This function will be used by revset.orset() and scmutil.revrange() to reduce
the stack depth from O(n) to O(log(n)).

We've bikeshed the interface of this function, but we couldn't come to an
agreement. So we decided to attempt to make it move forward.

 marmoute:
 - new factory function isn't necessary for balanced addsets
 - addset.__init__ can just recurse, should handle "len(subsets) == 2+"

 yuja:
 - want to write all "len(subsets) == 0, 1, 2, 3+" cases in the same function
 - no recursion in __init__ for cosmetic reason: can't return, can't call
   __init__ directly

I've changed it to a private function so that nobody would be tempted to
utilize it.

#!/usr/bin/env python
"""Test the running system for features availability. Exit with zero
if all features are there, non-zero otherwise. If a feature name is
prefixed with "no-", the absence of feature is tested.
"""
import optparse
import sys
import hghave

checks = hghave.checks

def list_features():
    for name, feature in sorted(checks.iteritems()):
        desc = feature[1]
        print name + ':', desc

def test_features():
    failed = 0
    for name, feature in checks.iteritems():
        check, _ = feature
        try:
            check()
        except Exception, e:
            print "feature %s failed:  %s" % (name, e)
            failed += 1
    return failed

parser = optparse.OptionParser("%prog [options] [features]")
parser.add_option("--test-features", action="store_true",
                  help="test available features")
parser.add_option("--list-features", action="store_true",
                  help="list available features")
parser.add_option("-q", "--quiet", action="store_true",
                  help="check features silently")

if __name__ == '__main__':
    options, args = parser.parse_args()
    if options.list_features:
        list_features()
        sys.exit(0)

    if options.test_features:
        sys.exit(test_features())

    quiet = options.quiet

    failures = 0

    def error(msg):
        global failures
        if not quiet:
            sys.stderr.write(msg + '\n')
        failures += 1

    for feature in args:
        negate = feature.startswith('no-')
        if negate:
            feature = feature[3:]

        if feature not in checks:
            error('skipped: unknown feature: ' + feature)
            sys.exit(2)

        check, desc = checks[feature]
        try:
            available = check()
        except Exception, e:
            error('hghave check failed: ' + feature)
            continue

        if not negate and not available:
            error('skipped: missing feature: ' + desc)
        elif negate and available:
            error('skipped: system supports %s' % desc)

    if failures != 0:
        sys.exit(1)