Subzero: Add a proper default for --pnacl-bin-path .

pydir/run-pnacl-sz.py

 #!/usr/bin/env python2
 
 import argparse
 import itertools
 import os
 import re
 import subprocess
 import sys
 import tempfile
 
-from utils import shellcmd
+from utils import FindBaseNaCl, shellcmd
 
 
 def TargetAssemblerFlags(target, sandboxed):
   # TODO(reed kotler). Need to find out exactly we need to
   # add here for Mips32.
   flags = { 'x8632': ['-triple=%s' % ('i686-nacl' if sandboxed else 'i686')],
             'arm32': ['-triple=%s' % (
                           'armv7a-nacl' if sandboxed else 'armv7a'),
                       '-mcpu=cortex-a9', '-mattr=+neon'],
             'mips32': ['-triple=mipsel' ] }
@@ skipping 31 matching lines @@
                            'convert to Subzero')
     argparser.add_argument('--llvm-source', required=False,
                            action='store_true',
                            help='Parse source directly into llvm IR ' +
                            '(without generating a pexe), then ' +
                            'convert to Subzero')
     argparser.add_argument(
         '--pnacl-sz', required=False, default='./pnacl-sz', metavar='PNACL-SZ',
         help="Subzero translator 'pnacl-sz'")
     argparser.add_argument('--pnacl-bin-path', required=False,
-                           default=None, metavar='PNACL_BIN_PATH',
+                           default=(
+                             '{root}/toolchain/linux_x86/pnacl_newlib_raw/bin'
+                           ).format(root=FindBaseNaCl()),
+                           metavar='PNACL_BIN_PATH',
                            help='Path to LLVM & Binutils executables ' +
                                 '(e.g. for building PEXE files)')
     argparser.add_argument('--assemble', required=False,
                            action='store_true',
                            help='Assemble the output')
     argparser.add_argument('--disassemble', required=False,
                            action='store_true',
                            help='Disassemble the assembled output')
     argparser.add_argument('--dis-flags', required=False,
                            action='append', default=[],
@@ skipping 88 matching lines @@
               [asm_temp.name])
 
     stdout_result = shellcmd(cmd, echo=args.echo_cmd)
     if not args.echo_cmd:
       sys.stdout.write(stdout_result)
     if asm_temp:
       os.remove(asm_temp.name)
 
 if __name__ == '__main__':
     main()