Re: bad dynamic mem access in final.c

[Jeffrey A Law <law at cygnus dot com>]

  In message <20000227230730.A1661@rjlhome.sco.com>you write:
  > shorten_branches computes max_uid as 218 and then calls xcalloc to get
  > space for 218 ints and calls it "insn_addresses".
  > 
  > So later, final() comes along and loops over the available insns
  > 
  > 	 for (insn = NEXT_INSN (first); insn;)
  > 		insn_current_address = insn_addresses[INSN_UID (insn)];
  > 
  > Boom!  We just walked past the end of insn_addresses.  Interestingly,
  > it computes max_uid to be 219 and that is the value of INSN_UID(insn)
  > in the evaluated expression that causes grief.  It's not clear, but I
  > suspect this is an "off by two" error and not an "off by one".
More likely something has created a new insn between the call to
computation of max_uid as 218 and the access to insn_addresses.

You might be able to track this down by putting a breakpoint in
make_insn_raw or one of its related routines after the computation]
of max_uid.  From there you should be able to track down what
code is creating new insns and causing the out of bounds array
access.

Of course, this is an old message, so maybe you (or someone else) has
already fixed this problem.


jeff