Re: [Gnu-arch-users] PANIC: Top-of-file arch tag crosses 1k boundary

[Robert Anderson]

--- Original Message ---
From: Aaron Bentley <address@hidden>
To: Robert Anderson <address@hidden>
CC: address@hidden
Subject: Re: [Gnu-arch-users] PANIC: Top-of-file arch tag crosses
1k boundary

>Robert Anderson wrote:
>> This is the error messages I get when I do 'tla changes' using
>> the 1.2.1, which I just installed:
>> 
>> PANIC: Top-of-file arch tag crosses 1k boundary
>> 
>> Any ideas?  I don't have any arch-tags at the top of files.  I do
>> have some in very small files, however, that I suppose could be
>> interpreted as the "top" even though they are closer to the
>> bottom than the top.
>
>Urk.
>
>Try to avoid one bug, you get another.  The rationale was that
ids were 
>being truncated when their tags crossed the 1K boundary.  Rather
than 
>fix it hastily, a PANIC was added, to prevent tla from silently
doing 
>the wrong thing.

Let me see if I understand.  There are two allowable places for
tags in the file:  1k starting from the beginning of the file,
and the last 1k of the file.

The algorithm for finding a tag is: search the top, and if none
is found, then search the bottom for the tag identifier.  If
found in the "top", do this barrier-cross check on the tag to
prevent unintended truncation.

The failure mode here is that the tag was intended to be at the
bottom of the file, but the file is short enough that the tag is
in _both_ the "bottom" and "top" regions, although only partially
contained in the "top" region.

Shouldn't the algorithm look for the tag at the "bottom" location
_first_?  And only if no tag is found, to search the top?

Bob