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1#!/usr/bin/env python
2
3import os
4import re
5import subprocess
6import sys
7import tempfile
8
9###
10
11class DeltaAlgorithm(object):
12    def __init__(self):
13        self.cache = set()
14
15    def test(self, changes):
16        abstract
17
18    ###
19
20    def getTestResult(self, changes):
21        # There is no reason to cache successful tests because we will
22        # always reduce the changeset when we see one.
23
24        changeset = frozenset(changes)
25        if changeset in self.cache:
26            return False
27        elif not self.test(changes):
28            self.cache.add(changeset)
29            return False
30        else:
31            return True
32
33    def run(self, changes, force=False):
34        # Make sure the initial test passes, if not then (a) either
35        # the user doesn't expect monotonicity, and we may end up
36        # doing O(N^2) tests, or (b) the test is wrong. Avoid the
37        # O(N^2) case unless user requests it.
38        if not force:
39            if not self.getTestResult(changes):
40                raise ValueError,'Initial test passed to delta fails.'
41
42        # Check empty set first to quickly find poor test functions.
43        if self.getTestResult(set()):
44            return set()
45        else:
46            return self.delta(changes, self.split(changes))
47
48    def split(self, S):
49        """split(set) -> [sets]
50
51        Partition a set into one or two pieces.
52        """
53
54        # There are many ways to split, we could do a better job with more
55        # context information (but then the API becomes grosser).
56        L = list(S)
57        mid = len(L)//2
58        if mid==0:
59            return L,
60        else:
61            return L[:mid],L[mid:]
62
63    def delta(self, c, sets):
64        # assert(reduce(set.union, sets, set()) == c)
65
66        # If there is nothing left we can remove, we are done.
67        if len(sets) <= 1:
68            return c
69
70        # Look for a passing subset.
71        res = self.search(c, sets)
72        if res is not None:
73            return res
74
75        # Otherwise, partition sets if possible; if not we are done.
76        refined = sum(map(list, map(self.split, sets)), [])
77        if len(refined) == len(sets):
78            return c
79
80        return self.delta(c, refined)
81
82    def search(self, c, sets):
83        for i,S in enumerate(sets):
84            # If test passes on this subset alone, recurse.
85            if self.getTestResult(S):
86                return self.delta(S, self.split(S))
87
88            # Otherwise if we have more than two sets, see if test
89            # pases without this subset.
90            if len(sets) > 2:
91                complement = sum(sets[:i] + sets[i+1:],[])
92                if self.getTestResult(complement):
93                    return self.delta(complement, sets[:i] + sets[i+1:])
94
95###
96
97class Token:
98    def __init__(self, type, data, flags, file, line, column):
99        self.type   = type
100        self.data   = data
101        self.flags  = flags
102        self.file   = file
103        self.line   = line
104        self.column = column
105
106kTokenRE = re.compile(r"""([a-z_]+) '(.*)'\t(.*)\tLoc=<(.*):(.*):(.*)>""",
107                      re.DOTALL | re.MULTILINE)
108
109def getTokens(path):
110    p = subprocess.Popen(['clang','-dump-raw-tokens',path],
111                         stdin=subprocess.PIPE,
112                         stdout=subprocess.PIPE,
113                         stderr=subprocess.PIPE)
114    out,err = p.communicate()
115
116    tokens = []
117    collect = None
118    for ln in err.split('\n'):
119        # Silly programmers refuse to print in simple machine readable
120        # formats. Whatever.
121        if collect is None:
122            collect = ln
123        else:
124            collect = collect + '\n' + ln
125        if 'Loc=<' in ln and ln.endswith('>'):
126            ln,collect = collect,None
127            tokens.append(Token(*kTokenRE.match(ln).groups()))
128
129    return tokens
130
131###
132
133class TMBDDelta(DeltaAlgorithm):
134    def __init__(self, testProgram, tokenLists, log):
135        def patchName(name, suffix):
136            base,ext = os.path.splitext(name)
137            return base + '.' + suffix + ext
138        super(TMBDDelta, self).__init__()
139        self.testProgram = testProgram
140        self.tokenLists = tokenLists
141        self.tempFiles = [patchName(f,'tmp')
142                            for f,_ in self.tokenLists]
143        self.targetFiles = [patchName(f,'ok')
144                            for f,_ in self.tokenLists]
145        self.log = log
146        self.numTests = 0
147
148    def writeFiles(self, changes, fileNames):
149        assert len(fileNames) == len(self.tokenLists)
150        byFile = [[] for i in self.tokenLists]
151        for i,j in changes:
152            byFile[i].append(j)
153
154        for i,(file,tokens) in enumerate(self.tokenLists):
155            f = open(fileNames[i],'w')
156            for j in byFile[i]:
157                f.write(tokens[j])
158            f.close()
159
160        return byFile
161
162    def test(self, changes):
163        self.numTests += 1
164
165        byFile = self.writeFiles(changes, self.tempFiles)
166
167        if self.log:
168            print >>sys.stderr, 'TEST - ',
169            if self.log > 1:
170                for i,(file,_) in enumerate(self.tokenLists):
171                    indices = byFile[i]
172                    if i:
173                        sys.stderr.write('\n      ')
174                    sys.stderr.write('%s:%d tokens: [' % (file,len(byFile[i])))
175                    prev = None
176                    for j in byFile[i]:
177                        if prev is None or j != prev + 1:
178                            if prev:
179                                sys.stderr.write('%d][' % prev)
180                            sys.stderr.write(str(j))
181                            sys.stderr.write(':')
182                        prev = j
183                    if byFile[i]:
184                        sys.stderr.write(str(byFile[i][-1]))
185                    sys.stderr.write('] ')
186            else:
187                print >>sys.stderr, ', '.join(['%s:%d tokens' % (file, len(byFile[i]))
188                                               for i,(file,_) in enumerate(self.tokenLists)]),
189
190        p = subprocess.Popen([self.testProgram] + self.tempFiles)
191        res = p.wait() == 0
192
193        if res:
194            self.writeFiles(changes, self.targetFiles)
195
196        if self.log:
197            print >>sys.stderr, '=> %s' % res
198        else:
199            if res:
200                print '\nSUCCESS (%d tokens)' % len(changes)
201            else:
202                sys.stderr.write('.')
203
204        return res
205
206    def run(self):
207        res = super(TMBDDelta, self).run([(i,j)
208                                          for i,(file,tokens) in enumerate(self.tokenLists)
209                                          for j in range(len(tokens))])
210        self.writeFiles(res, self.targetFiles)
211        if not self.log:
212            print >>sys.stderr
213        return res
214
215def tokenBasedMultiDelta(program, files, log):
216    # Read in the lists of tokens.
217    tokenLists = [(file, [t.data for t in getTokens(file)])
218                  for file in files]
219
220    numTokens = sum([len(tokens) for _,tokens in tokenLists])
221    print "Delta on %s with %d tokens." % (', '.join(files), numTokens)
222
223    tbmd = TMBDDelta(program, tokenLists, log)
224
225    res = tbmd.run()
226
227    print "Finished %s with %d tokens (in %d tests)." % (', '.join(tbmd.targetFiles),
228                                                         len(res),
229                                                         tbmd.numTests)
230
231def main():
232    from optparse import OptionParser, OptionGroup
233    parser = OptionParser("%prog <test program> {files+}")
234    parser.add_option("", "--debug", dest="debugLevel",
235                     help="set debug level [default %default]",
236                     action="store", type=int, default=0)
237    (opts, args) = parser.parse_args()
238
239    if len(args) <= 1:
240        parser.error('Invalid number of arguments.')
241
242    program,files = args[0],args[1:]
243
244    md = tokenBasedMultiDelta(program, files, log=opts.debugLevel)
245
246if __name__ == '__main__':
247    try:
248        main()
249    except KeyboardInterrupt:
250        print >>sys.stderr,'Interrupted.'
251        os._exit(1) # Avoid freeing our giant cache.
252