🚀 go-pugleaf

Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:
> On 2018-03-02, Bob Eager <news...@eager.cx> wrote:
> 
>> On Fri, 02 Mar 2018 01:11:55 +0000, Charlie Gibbs wrote:
>> 
>>> On 2018-03-01, Bob Eager <news...@eager.cx> wrote:
>>> 
>>>> On Thu, 01 Mar 2018 16:41:20 -0600, Charles Richmond wrote:
>>>> 
>>>>> Cross references were good to use with a hex dump of your program.  In
>>>>> the early 1980's I used a cross reference and a hex dump to find the
>>>>> value of FORTRAN variables at the time the program crashed.
>>>>> numerist at aquaporin4 dot com
>>>>> 
>>>>> Using DDT under TOPS-10 or dbx under Unix, or gdb under Linux... one
>>>>> can find the value of variables when the program "dumped core".  This
>>>>> obviated the need for a cross reference.
>>>> 
>>>> I think that's conflating two separate things:
>>>> a) cross reference b) symbol table
>>> 
>>> A cross-reference listing is a symbol table dump with reference data
>>> added.
>> 
>> I have rarely seen the two combined. A symbol table is names and 
>> (possibly relocatable) offsets in a PSECT ot whatever. A cross reference 
>> is names and line numbers. The two have different purposes, and I have 
>> seen many assemblers where you can request one or both of those - 
>> separately.
> 
> Perhaps I overgeneralized.  Indeed, a freestanding cross-reference
> utility would have to do a lot of work to provide more than the
> line number in which a symbol was defined and the line numbers in
> which it was referenced.  The assembler or compiler, on the other
> hand, knows the symbol's value, length attribute, type attribute,
> relocation attribute, etc.  If it writes these out to a work file,
> along with line numbers where the symbol is used, it's possible
> to generate a pretty comprehensive report from the result.
> 

Vey simple-minded example (just for you young whippersnappers who never
worked with a compiler that generated a cross-reference):

http://www.iron-spring.com/FreeStuff/cross_ref_examp.txt

-- 
Pete