Fix objdump assembly truncations

tools/objdump-v8

 #!/usr/bin/env python
 #
 # Copyright 2016 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
 #       with the distribution.
 #     * Neither the name of Google Inc. nor the names of its
 #       contributors may be used to endorse or promote products derived
 #       from this software without specific prior written permission.
 #
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+import os.path
 import re
 import subprocess
 import sys
 
 
 def get_address_bounds():
   start = -1
   end = -1
   for arg in sys.argv:
     if arg.startswith("--start-address="):
       start = int(arg[-12:], 16)
     if arg.startswith("--stop-address="):
       end = int(arg[-12:], 16)
   return start, end
 
 
 def format_line(line):
   pieces = line.split(None, 3)
   return " " + pieces[0][2:] + ":\t" + pieces[3]
 
 
 def is_comment(line):
   stripped = line.strip()
-  return stripped.startswith("--") or stripped.startswith(";;;")
+  return stripped.startswith("--") or stripped.startswith(";;")
 
 def main():
   filename = sys.argv[-1]
   match = re.match(r"/tmp/perf-(.*)\.map", filename)
   if match:
     start, end = get_address_bounds()
-    codefile = "code-" + match.group(1) + "-1.asm"
-    with open(codefile, "r") as code:
+    process_codefile = "code-" + match.group(1) + "-1.asm"
+    if os.path.exists(process_codefile):
+      codefile = open(process_codefile, "r")
+    else:
+      codefile = open("code.asm", "r")
+    with codefile:
       printing = False
-      for line in code:
+      for line in codefile:
         if line.startswith("0x"):
           addr = int(line.split()[0], 0)
           if start <= addr <= end:
             printing = True
             sys.stdout.write(format_line(line))
           elif printing:
             break
         elif printing and not is_comment(line):
           break
   else:
     sys.argv[0] = "objdump"
     sys.exit(subprocess.call(sys.argv))
 
 if __name__ == "__main__":
   main()