ppapi/generators/idl_diff.py

   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:]))