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      1 #!/usr/bin/env python
      2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
      3 # Use of this source code is governed by a BSD-style license that can be
      4 # found in the LICENSE file.
      5 
      6 import glob
      7 import os
      8 import subprocess
      9 import sys
     10 
     11 from idl_option import GetOption, Option, ParseOptions
     12 from idl_outfile import IDLOutFile
     13 #
     14 # IDLDiff
     15 #
     16 # IDLDiff is a tool for comparing sets of IDL generated header files
     17 # with the standard checked in headers.  It does this by capturing the
     18 # output of the standard diff tool, parsing it into separate changes, then
     19 # ignoring changes that are know to be safe, such as adding or removing
     20 # blank lines, etc...
     21 #
     22 
     23 Option('gen', 'IDL generated files', default='hdir')
     24 Option('src', 'Original ".h" files', default='../c')
     25 Option('halt', 'Stop if a difference is found')
     26 Option('diff', 'Directory holding acceptable diffs', default='diff')
     27 Option('ok', 'Write out the diff file.')
     28 # Change
     29 #
     30 # A Change object contains the previous lines, new news and change type.
     31 #
     32 class Change(object):
     33   def __init__(self, mode, was, now):
     34     self.mode = mode
     35     self.was = was
     36     self.now = now
     37 
     38   def Dump(self):
     39     if not self.was:
     40       print 'Adding %s' % self.mode
     41     elif not self.now:
     42       print 'Missing %s' % self.mode
     43     else:
     44       print 'Modifying %s' % self.mode
     45 
     46     for line in self.was:
     47       print 'src: >>%s<<' % line
     48     for line in self.now:
     49       print 'gen: >>%s<<' % line
     50     print
     51 
     52 #
     53 # IsCopyright
     54 #
     55 # Return True if this change is only a one line change in the copyright notice
     56 # such as non-matching years.
     57 #
     58 def IsCopyright(change):
     59   if len(change.now) != 1 or len(change.was) != 1: return False
     60   if 'Copyright (c)' not in change.now[0]: return False
     61   if 'Copyright (c)' not in change.was[0]: return False
     62   return True
     63 
     64 #
     65 # IsBlankComment
     66 #
     67 # Return True if this change only removes a blank line from a comment
     68 #
     69 def IsBlankComment(change):
     70   if change.now: return False
     71   if len(change.was) != 1: return False
     72   if change.was[0].strip() != '*': return False
     73   return True
     74 
     75 #
     76 # IsBlank
     77 #
     78 # Return True if this change only adds or removes blank lines
     79 #
     80 def IsBlank(change):
     81   for line in change.now:
     82     if line: return False
     83   for line in change.was:
     84     if line: return False
     85   return True
     86 
     87 
     88 #
     89 # IsCppComment
     90 #
     91 # Return True if this change only going from C++ to C style
     92 #
     93 def IsToCppComment(change):
     94   if not len(change.now) or len(change.now) != len(change.was):
     95     return False
     96   for index in range(len(change.now)):
     97     was = change.was[index].strip()
     98     if was[:2] != '//':
     99       return False
    100     was = was[2:].strip()
    101     now = change.now[index].strip()
    102     if now[:2] != '/*':
    103       return False
    104     now = now[2:-2].strip()
    105     if now != was:
    106       return False
    107   return True
    108 
    109 
    110   return True
    111 
    112 def IsMergeComment(change):
    113   if len(change.was) != 1: return False
    114   if change.was[0].strip() != '*': return False
    115   for line in change.now:
    116     stripped = line.strip()
    117     if stripped != '*' and stripped[:2] != '/*' and stripped[-2:] != '*/':
    118       return False
    119   return True
    120 #
    121 # IsSpacing
    122 #
    123 # Return True if this change is only different in the way 'words' are spaced
    124 # such as in an enum:
    125 #   ENUM_XXX   = 1,
    126 #   ENUM_XYY_Y = 2,
    127 # vs
    128 #   ENUM_XXX = 1,
    129 #   ENUM_XYY_Y = 2,
    130 #
    131 def IsSpacing(change):
    132   if len(change.now) != len(change.was): return False
    133   for i in range(len(change.now)):
    134     # Also ignore right side comments
    135     line = change.was[i]
    136     offs = line.find('//')
    137     if offs == -1:
    138       offs = line.find('/*')
    139     if offs >-1:
    140       line = line[:offs-1]
    141 
    142     words1 = change.now[i].split()
    143     words2 = line.split()
    144     if words1 != words2: return False
    145   return True
    146 
    147 #
    148 # IsInclude
    149 #
    150 # Return True if change has extra includes
    151 #
    152 def IsInclude(change):
    153   for line in change.was:
    154     if line.strip().find('struct'): return False
    155   for line in change.now:
    156     if line and '#include' not in line: return False
    157   return True
    158 
    159 #
    160 # IsCppComment
    161 #
    162 # Return True if the change is only missing C++ comments
    163 #
    164 def IsCppComment(change):
    165   if len(change.now): return False
    166   for line in change.was:
    167     line = line.strip()
    168     if line[:2] != '//': return False
    169   return True
    170 #
    171 # ValidChange
    172 #
    173 # Return True if none of the changes does not patch an above "bogus" change.
    174 #
    175 def ValidChange(change):
    176   if IsToCppComment(change): return False
    177   if IsCopyright(change): return False
    178   if IsBlankComment(change): return False
    179   if IsMergeComment(change): return False
    180   if IsBlank(change): return False
    181   if IsSpacing(change): return False
    182   if IsInclude(change): return False
    183   if IsCppComment(change): return False
    184   return True
    185 
    186 
    187 #
    188 # Swapped
    189 #
    190 # Check if the combination of last + next change signals they are both
    191 # invalid such as swap of line around an invalid block.
    192 #
    193 def Swapped(last, next):
    194   if not last.now and not next.was and len(last.was) == len(next.now):
    195     cnt = len(last.was)
    196     for i in range(cnt):
    197       match = True
    198       for j in range(cnt):
    199         if last.was[j] != next.now[(i + j) % cnt]:
    200           match = False
    201           break;
    202       if match: return True
    203   if not last.was and not next.now and len(last.now) == len(next.was):
    204     cnt = len(last.now)
    205     for i in range(cnt):
    206       match = True
    207       for j in range(cnt):
    208         if last.now[i] != next.was[(i + j) % cnt]:
    209           match = False
    210           break;
    211       if match: return True
    212   return False
    213 
    214 
    215 def FilterLinesIn(output):
    216   was = []
    217   now = []
    218   filter = []
    219   for index in range(len(output)):
    220     filter.append(False)
    221     line = output[index]
    222     if len(line) < 2: continue
    223     if line[0] == '<':
    224       if line[2:].strip() == '': continue
    225       was.append((index, line[2:]))
    226     elif line[0] == '>':
    227       if line[2:].strip() == '': continue
    228       now.append((index, line[2:]))
    229   for windex, wline in was:
    230     for nindex, nline in now:
    231       if filter[nindex]: continue
    232       if filter[windex]: continue
    233       if wline == nline:
    234         filter[nindex] = True
    235         filter[windex] = True
    236         if GetOption('verbose'):
    237           print "Found %d, %d >>%s<<" % (windex + 1, nindex + 1, wline)
    238   out = []
    239   for index in range(len(output)):
    240     if not filter[index]:
    241       out.append(output[index])
    242 
    243   return out
    244 #
    245 # GetChanges
    246 #
    247 # Parse the output into discrete change blocks.
    248 #
    249 def GetChanges(output):
    250   # Split on lines, adding an END marker to simply add logic
    251   lines = output.split('\n')
    252   lines = FilterLinesIn(lines)
    253   lines.append('END')
    254 
    255   changes = []
    256   was = []
    257   now = []
    258   mode = ''
    259   last = None
    260 
    261   for line in lines:
    262 #    print "LINE=%s" % line
    263     if not line: continue
    264 
    265     elif line[0] == '<':
    266       if line[2:].strip() == '': continue
    267       # Ignore prototypes
    268       if len(line) > 10:
    269         words = line[2:].split()
    270         if len(words) == 2 and words[1][-1] == ';':
    271           if words[0] == 'struct' or words[0] == 'union':
    272             continue
    273       was.append(line[2:])
    274     elif line[0] == '>':
    275       if line[2:].strip() == '': continue
    276       if line[2:10] == '#include': continue
    277       now.append(line[2:])
    278     elif line[0] == '-':
    279       continue
    280     else:
    281       change = Change(line, was, now)
    282       was = []
    283       now = []
    284       if ValidChange(change):
    285           changes.append(change)
    286       if line == 'END':
    287         break
    288 
    289   return FilterChanges(changes)
    290 
    291 def FilterChanges(changes):
    292   if len(changes) < 2: return changes
    293   out = []
    294   filter = [False for change in changes]
    295   for cur in range(len(changes)):
    296     for cmp in range(cur+1, len(changes)):
    297       if filter[cmp]:
    298         continue
    299       if Swapped(changes[cur], changes[cmp]):
    300         filter[cur] = True
    301         filter[cmp] = True
    302   for cur in range(len(changes)):
    303     if filter[cur]: continue
    304     out.append(changes[cur])
    305   return out
    306 
    307 def Main(args):
    308   filenames = ParseOptions(args)
    309   if not filenames:
    310     gendir = os.path.join(GetOption('gen'), '*.h')
    311     filenames = sorted(glob.glob(gendir))
    312     srcdir = os.path.join(GetOption('src'), '*.h')
    313     srcs = sorted(glob.glob(srcdir))
    314     for name in srcs:
    315       name = os.path.split(name)[1]
    316       name = os.path.join(GetOption('gen'), name)
    317       if name not in filenames:
    318         print 'Missing: %s' % name
    319 
    320   for filename in filenames:
    321     gen = filename
    322     filename = filename[len(GetOption('gen')) + 1:]
    323     src = os.path.join(GetOption('src'), filename)
    324     diff = os.path.join(GetOption('diff'), filename)
    325     p = subprocess.Popen(['diff', src, gen], stdout=subprocess.PIPE)
    326     output, errors = p.communicate()
    327 
    328     try:
    329       input = open(diff, 'rt').read()
    330     except:
    331       input = ''
    332 
    333     if input != output:
    334       changes = GetChanges(output)
    335     else:
    336       changes = []
    337 
    338     if changes:
    339       print "\n\nDelta between:\n  src=%s\n  gen=%s\n" % (src, gen)
    340       for change in changes:
    341         change.Dump()
    342       print 'Done with %s\n\n' % src
    343       if GetOption('ok'):
    344         open(diff, 'wt').write(output)
    345       if GetOption('halt'):
    346         return 1
    347     else:
    348       print "\nSAME:\n  src=%s\n  gen=%s" % (src, gen)
    349       if input: print '  ** Matched expected diff. **'
    350       print '\n'
    351 
    352 
    353 if __name__ == '__main__':
    354   sys.exit(Main(sys.argv[1:]))
    355