Subzero: Change the szbuild.py --force default.

pydir/szbuild.py

 #!/usr/bin/env python2
 
 import argparse
 import os
 import pipes
 import re
 import sys
 
 from utils import shellcmd, FindBaseNaCl, get_sfi_string
 
@@ skipping 43 matching lines @@
     """
     if re_exclude.match(sym):
         # Always honor an explicit exclude before considering
         # includes.
         return False
     if re_include.match(sym):
         return True
     return default_match
 
 def AddOptionalArgs(argparser):
-    argparser.add_argument('--force', dest='force', action='store_true',
-                           help='Force all re-translations of the pexe')
+    argparser.add_argument('--force', dest='force', type=int, choices=[0, 1],
+                           default=1,
+                           help='Force all re-translations of the pexe.' +
+                                ' Default %(default)s.')
     argparser.add_argument('--include', '-i', default=[], dest='include',
                            action='append',
                            help='Subzero symbols to include ' +
                                 '(regex or line range)')
     argparser.add_argument('--exclude', '-e', default=[], dest='exclude',
                            action='append',
                            help='Subzero symbols to exclude ' +
                                 '(regex or line range)')
     argparser.add_argument('--output', '-o', default='a.out', dest='output',
                            action='store',
@@ skipping 157 matching lines @@
 
     Each --include and --exclude argument can be a regular expression or a range
     of lines in the symbol file.  Each regular expression is wrapped inside
     '^$', so if you want a substring match on 'foo', use '.*foo.*' instead.
     Ranges use python-style 'first:last' notation, so e.g. use '0:10' or ':10'
     for the first 10 lines of the file, or '1' for the second line of the file.
 
     If no --include or --exclude arguments are given, the executable is produced
     entirely using Subzero, without using llc or linker tricks.
 
-    This script uses file modification timestamps to determine whether llc and
-    Subzero re-translation are needed.  It checks timestamps of llc, pnacl-sz,
-    and the pexe against the translated object files to determine the minimal
-    work necessary.  The --force option suppresses those checks and
-    re-translates everything.
+    When using the --force=0 option, this script uses file modification
+    timestamps to determine whether llc and Subzero re-translation are needed.
+    It checks timestamps of llc, pnacl-sz, and the pexe against the translated
+    object files to determine the minimal work necessary.  The --force=1 option
+    (default) suppresses those checks and re-translates everything.
 
     This script expects various PNaCl and LLVM tools to be found within the
     native_client tree.  When changes are made to these tools, copy them this
     way:
       cd native_client
       toolchain_build/toolchain_build_pnacl.py llvm_x86_64_linux \\
       --install=toolchain/linux_x86/pnacl_newlib_raw
     """
     argparser = argparse.ArgumentParser(
         description='    ' + main.__doc__,
@@ skipping 189 matching lines @@
 
     # Put the extra verbose printing at the end.
     if args.verbose and hybrid:
         print 'include={regex}'.format(regex=re_include_str)
         print 'exclude={regex}'.format(regex=re_exclude_str)
         print 'default_match={dm}'.format(dm=default_match)
         print 'Number of Subzero syms = {num}'.format(num=len(sz_syms))
 
 if __name__ == '__main__':
     main()