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#!/usr/bin/python
import sys, math, random, os, re, signal, tempfile, stat, errno, traceback
from heapq import heappush, heappop
from sets import Set
sys.path.append('@@GIT_PYTHON_PATH@@')
from gitMergeCommon import *
alwaysWriteTree = False
# The actual merge code
# ---------------------
def merge(h1, h2, branch1Name, branch2Name, graph, callDepth=0):
'''Merge the commits h1 and h2, return the resulting virtual
commit object and a flag indicating the cleaness of the merge.'''
assert(isinstance(h1, Commit) and isinstance(h2, Commit))
assert(isinstance(graph, Graph))
def infoMsg(*args):
sys.stdout.write(' '*callDepth)
printList(args)
infoMsg('Merging:')
infoMsg(h1)
infoMsg(h2)
sys.stdout.flush()
ca = getCommonAncestors(graph, h1, h2)
infoMsg('found', len(ca), 'common ancestor(s):')
for x in ca:
infoMsg(x)
sys.stdout.flush()
Ms = ca[0]
for h in ca[1:]:
[Ms, ignore] = merge(Ms, h,
'Temporary shared merge branch 1',
'Temporary shared merge branch 2',
graph, callDepth+1)
assert(isinstance(Ms, Commit))
if callDepth == 0:
if len(ca) > 1:
runProgram(['git-read-tree', h1.tree()])
runProgram(['git-update-cache', '-q', '--refresh'])
# Use the original index if we only have one common ancestor
updateWd = True
if alwaysWriteTree:
cleanCache = True
else:
cleanCache = False
else:
runProgram(['git-read-tree', h1.tree()])
updateWd = False
cleanCache = True
[shaRes, clean] = mergeTrees(h1.tree(), h2.tree(), Ms.tree(),
branch1Name, branch2Name,
cleanCache, updateWd)
if clean or cleanCache:
res = Commit(None, [h1, h2], tree=shaRes)
graph.addNode(res)
else:
res = None
return [res, clean]
getFilesRE = re.compile('([0-9]+) ([a-z0-9]+) ([0-9a-f]{40})\t(.*)')
def getFilesAndDirs(tree):
files = Set()
dirs = Set()
out = runProgram(['git-ls-tree', '-r', '-z', tree])
for l in out.split('\0'):
m = getFilesRE.match(l)
if m:
if m.group(2) == 'tree':
dirs.add(m.group(4))
elif m.group(2) == 'blob':
files.add(m.group(4))
return [files, dirs]
class CacheEntry:
def __init__(self, path):
class Stage:
def __init__(self):
self.sha1 = None
self.mode = None
self.stages = [Stage(), Stage(), Stage()]
self.path = path
unmergedRE = re.compile('^([0-9]+) ([0-9a-f]{40}) ([1-3])\t(.*)$')
def unmergedCacheEntries():
'''Create a dictionary mapping file names to CacheEntry
objects. The dictionary contains one entry for every path with a
non-zero stage entry.'''
lines = runProgram(['git-ls-files', '-z', '--unmerged']).split('\0')
lines.pop()
res = {}
for l in lines:
m = unmergedRE.match(l)
if m:
mode = int(m.group(1), 8)
sha1 = m.group(2)
stage = int(m.group(3)) - 1
path = m.group(4)
if res.has_key(path):
e = res[path]
else:
e = CacheEntry(path)
res[path] = e
e.stages[stage].mode = mode
e.stages[stage].sha1 = sha1
else:
print 'Error: Merge program failed: Unexpected output from', \
'git-ls-files:', l
sys.exit(2)
return res
def mergeTrees(head, merge, common, branch1Name, branch2Name,
cleanCache, updateWd):
'''Merge the trees 'head' and 'merge' with the common ancestor
'common'. The name of the head branch is 'branch1Name' and the name of
the merge branch is 'branch2Name'. Return a tuple (tree, cleanMerge)
where tree is the resulting tree and cleanMerge is True iff the
merge was clean.'''
assert(isSha(head) and isSha(merge) and isSha(common))
if common == merge:
print 'Already uptodate!'
return [head, True]
if updateWd:
updateArg = '-u'
else:
updateArg = '-i'
runProgram(['git-read-tree', updateArg, '-m', common, head, merge])
cleanMerge = True
[tree, code] = runProgram('git-write-tree', returnCode=True)
tree = tree.rstrip()
if code != 0:
[files, dirs] = getFilesAndDirs(head)
[filesM, dirsM] = getFilesAndDirs(merge)
files.union_update(filesM)
dirs.union_update(dirsM)
cleanMerge = True
entries = unmergedCacheEntries()
for name in entries:
if not processEntry(entries[name], branch1Name, branch2Name,
files, dirs, cleanCache, updateWd):
cleanMerge = False
if cleanMerge or cleanCache:
tree = runProgram('git-write-tree').rstrip()
else:
tree = None
else:
cleanMerge = True
return [tree, cleanMerge]
def processEntry(entry, branch1Name, branch2Name, files, dirs,
cleanCache, updateWd):
'''Merge one cache entry. 'files' is a Set with the files in both of
the heads that we are going to merge. 'dirs' contains the
corresponding data for directories. If 'cleanCache' is True no
non-zero stages will be left in the cache for the path
corresponding to the entry 'entry'.'''
# cleanCache == True => Don't leave any non-stage 0 entries in the cache.
# False => Leave unmerged entries
# updateWd == True => Update the working directory to correspond to the cache
# False => Leave the working directory unchanged
# clean == True => non-conflict case
# False => conflict case
# If cleanCache == False then the cache shouldn't be updated if clean == False
def updateFile(clean, sha, mode, path):
if cleanCache or (not cleanCache and clean):
runProgram(['git-update-cache', '--add', '--cacheinfo',
'0%o' % mode, sha, path])
if updateWd:
prog = ['git-cat-file', 'blob', sha]
if stat.S_ISREG(mode):
try:
os.unlink(path)
except OSError:
pass
if mode & 0100:
mode = 0777
else:
mode = 0666
fd = os.open(path, os.O_WRONLY | os.O_TRUNC | os.O_CREAT, mode)
proc = subprocess.Popen(prog, stdout=fd)
proc.wait()
os.close(fd)
elif stat.S_ISLNK(mode):
linkTarget = runProgram(prog)
os.symlink(linkTarget, path)
else:
assert(False)
runProgram(['git-update-cache', '--', path])
def removeFile(clean, path):
if cleanCache or (not cleanCache and clean):
runProgram(['git-update-cache', '--force-remove', '--', path])
if updateWd:
try:
os.unlink(path)
except OSError, e:
if e.errno != errno.ENOENT and e.errno != errno.EISDIR:
raise
def uniquePath(path, branch):
newPath = path + '_' + branch
suffix = 0
while newPath in files or newPath in dirs:
suffix += 1
newPath = path + '_' + branch + '_' + str(suffix)
files.add(newPath)
return newPath
debug('processing', entry.path, 'clean cache:', cleanCache,
'wd:', updateWd)
cleanMerge = True
path = entry.path
oSha = entry.stages[0].sha1
oMode = entry.stages[0].mode
aSha = entry.stages[1].sha1
aMode = entry.stages[1].mode
bSha = entry.stages[2].sha1
bMode = entry.stages[2].mode
assert(oSha == None or isSha(oSha))
assert(aSha == None or isSha(aSha))
assert(bSha == None or isSha(bSha))
assert(oMode == None or type(oMode) is int)
assert(aMode == None or type(aMode) is int)
assert(bMode == None or type(bMode) is int)
if (oSha and (not aSha or not bSha)):
#
# Case A: Deleted in one
#
if (not aSha and not bSha) or \
(aSha == oSha and not bSha) or \
(not aSha and bSha == oSha):
# Deleted in both or deleted in one and unchanged in the other
if aSha:
print 'Removing ' + path
removeFile(True, path)
else:
# Deleted in one and changed in the other
cleanMerge = False
if not aSha:
print 'CONFLICT (del/mod): "' + path + '" deleted in', \
branch1Name, 'and modified in', branch2Name, \
'. Version', branch2Name, ' of "' + path + \
'" left in tree'
mode = bMode
sha = bSha
else:
print 'CONFLICT (mod/del): "' + path + '" deleted in', \
branch2Name, 'and modified in', branch1Name + \
'. Version', branch1Name, 'of "' + path + \
'" left in tree'
mode = aMode
sha = aSha
updateFile(False, sha, mode, path)
elif (not oSha and aSha and not bSha) or \
(not oSha and not aSha and bSha):
#
# Case B: Added in one.
#
if aSha:
addBranch = branch1Name
otherBranch = branch2Name
mode = aMode
sha = aSha
conf = 'file/dir'
else:
addBranch = branch2Name
otherBranch = branch1Name
mode = bMode
sha = bSha
conf = 'dir/file'
if path in dirs:
cleanMerge = False
newPath = uniquePath(path, addBranch)
print 'CONFLICT (' + conf + \
'): There is a directory with name "' + path + '" in', \
otherBranch + '. Adding "' + path + '" as "' + newPath + '"'
removeFile(False, path)
path = newPath
else:
print 'Adding "' + path + '"'
updateFile(True, sha, mode, path)
elif not oSha and aSha and bSha:
#
# Case C: Added in both (check for same permissions).
#
if aSha == bSha:
if aMode != bMode:
cleanMerge = False
print 'CONFLICT: File "' + path + \
'" added identically in both branches,'
print 'CONFLICT: but permissions conflict', '0%o' % aMode, \
'->', '0%o' % bMode
print 'CONFLICT: adding with permission:', '0%o' % aMode
updateFile(False, aSha, aMode, path)
else:
# This case is handled by git-read-tree
assert(False)
else:
cleanMerge = False
newPath1 = uniquePath(path, branch1Name)
newPath2 = uniquePath(path, branch2Name)
print 'CONFLICT (add/add): File "' + path + \
'" added non-identically in both branches.', \
'Adding "' + newPath1 + '" and "' + newPath2 + '" instead.'
removeFile(False, path)
updateFile(False, aSha, aMode, newPath1)
updateFile(False, bSha, bMode, newPath2)
elif oSha and aSha and bSha:
#
# case D: Modified in both, but differently.
#
print 'Auto-merging', path
orig = runProgram(['git-unpack-file', oSha]).rstrip()
src1 = runProgram(['git-unpack-file', aSha]).rstrip()
src2 = runProgram(['git-unpack-file', bSha]).rstrip()
[out, ret] = runProgram(['merge',
'-L', branch1Name + '/' + path,
'-L', 'orig/' + path,
'-L', branch2Name + '/' + path,
src1, orig, src2], returnCode=True)
if aMode == oMode:
mode = bMode
else:
mode = aMode
sha = runProgram(['git-hash-object', '-t', 'blob', '-w',
src1]).rstrip()
if ret != 0:
cleanMerge = False
print 'CONFLICT (content): Merge conflict in "' + path + '".'
updateFile(False, sha, mode, path)
else:
updateFile(True, sha, mode, path)
os.unlink(orig)
os.unlink(src1)
os.unlink(src2)
else:
print 'ERROR: Fatal merge failure.'
print "ERROR: Shouldn't happen"
sys.exit(2)
return cleanMerge
def usage():
print 'Usage:', sys.argv[0], ' <base>... -- <head> <remote>..'
sys.exit(2)
# main entry point as merge strategy module
# The first parameters up to -- are merge bases, and the rest are heads.
# This strategy module figures out merge bases itself, so we only
# get heads.
for nextArg in xrange(1, len(sys.argv)):
if sys.argv[nextArg] == '--':
if len(sys.argv) != nextArg + 3:
print 'Not handling anything other than two heads merge.'
sys.exit(2)
try:
h1 = firstBranch = sys.argv[nextArg + 1]
h2 = secondBranch = sys.argv[nextArg + 2]
except IndexError:
usage()
break
print 'Merging', h1, 'with', h2
try:
h1 = runProgram(['git-rev-parse', '--verify', h1 + '^0']).rstrip()
h2 = runProgram(['git-rev-parse', '--verify', h2 + '^0']).rstrip()
graph = buildGraph([h1, h2])
[res, clean] = merge(graph.shaMap[h1], graph.shaMap[h2],
firstBranch, secondBranch, graph)
print ''
except:
traceback.print_exc(None, sys.stderr)
sys.exit(2)
if clean:
sys.exit(0)
else:
print 'Automatic merge failed, fix up by hand'
sys.exit(1)
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