Subzero: Partial implementation of global initializers.

szdiff.py

 #!/usr/bin/env python2
 
 import argparse
 import itertools
 import re
 
 if __name__ == '__main__':
     """Compares a LLVM file with a subzero file for differences.
 
     Before comparing, the LLVM file is massaged to remove comments,
@@ skipping 24 matching lines @@
         help='Subzero bitcode file [default stdin]')
     args = argparser.parse_args()
     bitcode = args.llfile[0].readlines()
     sz_out = [ line.rstrip() for line in args.szfile.readlines()]
 
     # Filter certain lines and patterns from the input, and collect
     # the remainder into llc_out.
     llc_out = []
     tail_call = re.compile(' tail call ');
     trailing_comment = re.compile(';.*')
-    ignore_pattern = re.compile('^ *$|^declare|^@')
+    ignore_pattern = re.compile('|'.join([
+                '^ *$',     # all-whitespace lines
+                '^declare', # declarations without definitions
+                '^@.*\]$'   # PNaCl global declarations like:
+                            #   @v = external global [4 x i8]
+                ]))
     prev_line = None
     for line in bitcode:
         if prev_line:
             line = prev_line + line
             prev_line = None
         # Convert tail call into regular (non-tail) call.
         line = tail_call.sub(' call ', line)
         # Remove trailing comments and spaces.
         line = trailing_comment.sub('', line).rstrip()
         # Ignore blanks lines, forward declarations, and variable definitions.
@@ skipping 28 matching lines @@
             lines_diff += 1
             continue
         if sz_line: print 'SZ (%d)> %s' % (lines_total, sz_line)
         if llc_line: print 'LL (%d)> %s' % (lines_total, llc_line)
         return_code = 1
 
     if return_code == 0:
         message = 'Success (ignored %d diffs out of %d lines)'
         print message % (lines_diff, lines_total)
     exit(return_code)