ppapi/generators/idl_diff.py

   1 #!/usr/bin/python
   2 #
   3 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
   4 # Use of this source code is governed by a BSD-style license that can be
   5 # found in the LICENSE file.
   6
   7 import glob
   8 import os
   9 import subprocess
  10 import sys
  11
  12 from idl_option import GetOption, Option, ParseOptions
  13 from idl_outfile import IDLOutFile
  14 #
  15 # IDLDiff
  16 #
  17 # IDLDiff is a tool for comparing sets of IDL generated header files
  18 # with the standard checked in headers.  It does this by capturing the
  19 # output of the standard diff tool, parsing it into separate changes, then
  20 # ignoring changes that are know to be safe, such as adding or removing
  21 # blank lines, etc...
  22 #
  23
  24 Option('gen', 'IDL generated files', default='hdir')
  25 Option('src', 'Original ".h" files', default='../c')
  26 Option('halt', 'Stop if a difference is found')
  27 Option('diff', 'Directory holding acceptable diffs', default='diff')
  28 Option('ok', 'Write out the diff file.')
  29 # Change
  30 #
  31 # A Change object contains the previous lines, new news and change type.
  32 #
  33 class Change(object):
  34   def __init__(self, mode, was, now):
  35     self.mode = mode
  36     self.was = was
  37     self.now = now
  38
  39   def Dump(self):
  40     if not self.was:
  41       print 'Adding %s' % self.mode
  42     elif not self.now:
  43       print 'Missing %s' % self.mode
  44     else:
  45       print 'Modifying %s' % self.mode
  46
  47     for line in self.was:
  48       print 'src: >>%s<<' % line
  49     for line in self.now:
  50       print 'gen: >>%s<<' % line
  51     print
  52
  53 #
  54 # IsCopyright
  55 #
  56 # Return True if this change is only a one line change in the copyright notice
  57 # such as non-matching years.
  58 #
  59 def IsCopyright(change):
  60   if len(change.now) != 1 or len(change.was) != 1: return False
  61   if 'Copyright (c)' not in change.now[0]: return False
  62   if 'Copyright (c)' not in change.was[0]: return False
  63   return True
  64
  65 #
  66 # IsBlankComment
  67 #
  68 # Return True if this change only removes a blank line from a comment
  69 #
  70 def IsBlankComment(change):
  71   if change.now: return False
  72   if len(change.was) != 1: return False
  73   if change.was[0].strip() != '*': return False
  74   return True
  75
  76 #
  77 # IsBlank
  78 #
  79 # Return True if this change only adds or removes blank lines
  80 #
  81 def IsBlank(change):
  82   for line in change.now:
  83     if line: return False
  84   for line in change.was:
  85     if line: return False
  86   return True
  87
  88
  89 #
  90 # IsCppComment
  91 #
  92 # Return True if this change only going from C++ to C style
  93 #
  94 def IsToCppComment(change):
  95   if not len(change.now) or len(change.now) != len(change.was):
  96     return False
  97   for index in range(len(change.now)):
  98     was = change.was[index].strip()
  99     if was[:2] != '//':
 100       return False
 101     was = was[2:].strip()
 102     now = change.now[index].strip()
 103     if now[:2] != '/*':
 104       return False
 105     now = now[2:-2].strip()
 106     if now != was:
 107       return False
 108   return True
 109
 110
 111   return True
 112
 113 def IsMergeComment(change):
 114   if len(change.was) != 1: return False
 115   if change.was[0].strip() != '*': return False
 116   for line in change.now:
 117     stripped = line.strip()
 118     if stripped != '*' and stripped[:2] != '/*' and stripped[-2:] != '*/':
 119       return False
 120   return True
 121 #
 122 # IsSpacing
 123 #
 124 # Return True if this change is only different in the way 'words' are spaced
 125 # such as in an enum:
 126 #   ENUM_XXX   = 1,
 127 #   ENUM_XYY_Y = 2,
 128 # vs
 129 #   ENUM_XXX = 1,
 130 #   ENUM_XYY_Y = 2,
 131 #
 132 def IsSpacing(change):
 133   if len(change.now) != len(change.was): return False
 134   for i in range(len(change.now)):
 135     # Also ignore right side comments
 136     line = change.was[i]
 137     offs = line.find('//')
 138     if offs == -1:
 139       offs = line.find('/*')
 140     if offs >-1:
 141       line = line[:offs-1]
 142
 143     words1 = change.now[i].split()
 144     words2 = line.split()
 145     if words1 != words2: return False
 146   return True
 147
 148 #
 149 # IsInclude
 150 #
 151 # Return True if change has extra includes
 152 #
 153 def IsInclude(change):
 154   for line in change.was:
 155     if line.strip().find('struct'): return False
 156   for line in change.now:
 157     if line and '#include' not in line: return False
 158   return True
 159
 160 #
 161 # IsCppComment
 162 #
 163 # Return True if the change is only missing C++ comments
 164 #
 165 def IsCppComment(change):
 166   if len(change.now): return False
 167   for line in change.was:
 168     line = line.strip()
 169     if line[:2] != '//': return False
 170   return True
 171 #
 172 # ValidChange
 173 #
 174 # Return True if none of the changes does not patch an above "bogus" change.
 175 #
 176 def ValidChange(change):
 177   if IsToCppComment(change): return False
 178   if IsCopyright(change): return False
 179   if IsBlankComment(change): return False
 180   if IsMergeComment(change): return False
 181   if IsBlank(change): return False
 182   if IsSpacing(change): return False
 183   if IsInclude(change): return False
 184   if IsCppComment(change): return False
 185   return True
 186
 187
 188 #
 189 # Swapped
 190 #
 191 # Check if the combination of last + next change signals they are both
 192 # invalid such as swap of line around an invalid block.
 193 #
 194 def Swapped(last, next):
 195   if not last.now and not next.was and len(last.was) == len(next.now):
 196     cnt = len(last.was)
 197     for i in range(cnt):
 198       match = True
 199       for j in range(cnt):
 200         if last.was[j] != next.now[(i + j) % cnt]:
 201           match = False
 202           break;
 203       if match: return True
 204   if not last.was and not next.now and len(last.now) == len(next.was):
 205     cnt = len(last.now)
 206     for i in range(cnt):
 207       match = True
 208       for j in range(cnt):
 209         if last.now[i] != next.was[(i + j) % cnt]:
 210           match = False
 211           break;
 212       if match: return True
 213   return False
 214
 215
 216 def FilterLinesIn(output):
 217   was = []
 218   now = []
 219   filter = []
 220   for index in range(len(output)):
 221     filter.append(False)
 222     line = output[index]
 223     if len(line) < 2: continue
 224     if line[0] == '<':
 225       if line[2:].strip() == '': continue
 226       was.append((index, line[2:]))
 227     elif line[0] == '>':
 228       if line[2:].strip() == '': continue
 229       now.append((index, line[2:]))
 230   for windex, wline in was:
 231     for nindex, nline in now:
 232       if filter[nindex]: continue
 233       if filter[windex]: continue
 234       if wline == nline:
 235         filter[nindex] = True
 236         filter[windex] = True
 237         if GetOption('verbose'):
 238           print "Found %d, %d >>%s<<" % (windex + 1, nindex + 1, wline)
 239   out = []
 240   for index in range(len(output)):
 241     if not filter[index]:
 242       out.append(output[index])
 243
 244   return out
 245 #
 246 # GetChanges
 247 #
 248 # Parse the output into discrete change blocks.
 249 #
 250 def GetChanges(output):
 251   # Split on lines, adding an END marker to simply add logic
 252   lines = output.split('\n')
 253   lines = FilterLinesIn(lines)
 254   lines.append('END')
 255
 256   changes = []
 257   was = []
 258   now = []
 259   mode = ''
 260   last = None
 261
 262   for line in lines:
 263 #    print "LINE=%s" % line
 264     if not line: continue
 265
 266     elif line[0] == '<':
 267       if line[2:].strip() == '': continue
 268       # Ignore prototypes
 269       if len(line) > 10:
 270         words = line[2:].split()
 271         if len(words) == 2 and words[1][-1] == ';':
 272           if words[0] == 'struct' or words[0] == 'union':
 273             continue
 274       was.append(line[2:])
 275     elif line[0] == '>':
 276       if line[2:].strip() == '': continue
 277       if line[2:10] == '#include': continue
 278       now.append(line[2:])
 279     elif line[0] == '-':
 280       continue
 281     else:
 282       change = Change(line, was, now)
 283       was = []
 284       now = []
 285       if ValidChange(change):
 286           changes.append(change)
 287       if line == 'END':
 288         break
 289
 290   return FilterChanges(changes)
 291
 292 def FilterChanges(changes):
 293   if len(changes) < 2: return changes
 294   out = []
 295   filter = [False for change in changes]
 296   for cur in range(len(changes)):
 297     for cmp in range(cur+1, len(changes)):
 298       if filter[cmp]:
 299         continue
 300       if Swapped(changes[cur], changes[cmp]):
 301         filter[cur] = True
 302         filter[cmp] = True
 303   for cur in range(len(changes)):
 304     if filter[cur]: continue
 305     out.append(changes[cur])
 306   return out
 307
 308 def Main(args):
 309   filenames = ParseOptions(args)
 310   if not filenames:
 311     gendir = os.path.join(GetOption('gen'), '*.h')
 312     filenames = sorted(glob.glob(gendir))
 313     srcdir = os.path.join(GetOption('src'), '*.h')
 314     srcs = sorted(glob.glob(srcdir))
 315     for name in srcs:
 316       name = os.path.split(name)[1]
 317       name = os.path.join(GetOption('gen'), name)
 318       if name not in filenames:
 319         print 'Missing: %s' % name
 320
 321   for filename in filenames:
 322     gen = filename
 323     filename = filename[len(GetOption('gen')) + 1:]
 324     src = os.path.join(GetOption('src'), filename)
 325     diff = os.path.join(GetOption('diff'), filename)
 326     p = subprocess.Popen(['diff', src, gen], stdout=subprocess.PIPE)
 327     output, errors = p.communicate()
 328
 329     try:
 330       input = open(diff, 'rt').read()
 331     except:
 332       input = ''
 333
 334     if input != output:
 335       changes = GetChanges(output)
 336     else:
 337       changes = []
 338
 339     if changes:
 340       print "\n\nDelta between:\n  src=%s\n  gen=%s\n" % (src, gen)
 341       for change in changes:
 342         change.Dump()
 343       print 'Done with %s\n\n' % src
 344       if GetOption('ok'):
 345         open(diff, 'wt').write(output)
 346       if GetOption('halt'):
 347         return 1
 348     else:
 349       print "\nSAME:\n  src=%s\n  gen=%s" % (src, gen)
 350       if input: print '  ** Matched expected diff. **'
 351       print '\n'
 352
 353 if __name__ == '__main__':
 354   sys.exit(Main(sys.argv[1:]))
 355