Separate elaboration and parsing

[valtih1978]

It seems that VHDL tools separate parsing from elaboration. However, it
seems that some constructions are ambigous at syntax level. For
instnance, http://cs.stackexchange.com/questions/24032, target <=
prefix(argument) can be treated as either

element <= composite_name(10) // selecting an element

or

int_target <= integer(1.1) // conversion

How do the tools handle this case? How do they communicate to the
elaborator whether elements should be addressed or conversion function
instantiated?

 

[KJ]

It seems that VHDL tools separate parsing from elaboration. However, it

seems that some constructions are ambigous at syntax level. For

instnance, http://cs.stackexchange.com/questions/24032, target <=

prefix(argument) can be treated as either



element <= composite_name(10) // selecting an element



or



int_target <= integer(1.1) // conversion



How do the tools handle this case? How do they communicate to the

elaborator whether elements should be addressed or conversion function

instantiated?

They don't communicate. When the names 'composite_name' and 'integer' comeacross, that name must have already been defined. If they are not defined, you get an error saying that 'composite_name' is unrecognized. If they are defined but you are using them incorrectly (for example by passing in aninteger argument to something that is expecting a real) then you will get an error pointing out what you're doing wrong.

Kevin Jennings

 

[valtih1978]

They don't communicate. When the names 'composite_name' and
'integer' come across, that name must have already been defined. If
they are not defined, you get an error saying that 'composite_name'
is unrecognized. If they are defined but you are using them
incorrectly (for example by passing in an integer argument to
something that is expecting a real) then you will get an error
pointing out what you're doing wrong.

You basically say that parser does the elaboration (if "The process by
which a declaration achieves its effect is called the elaboration of the
declaration" is not elaboration then what is elaboration?) for the
purpose of mantaining the list of defined objects and, thereby, is not
related with elaboration. Try once more. That statement as it is is pure
nonsense.

 

[valtih1978]

Why Fortran? Do you know that meaning of the symbol depends on the
scope? So, how many tables do you need in VHDL? Do you mean that there
is a difference between elaborating the definitions and building all
those tables?

 

[valtih1978]

Particularly, parser works at per-file basis. Yet, file may refer
objects defined in another file (package), which parser have no idea of.
Only elaborator is aware of their nature. How do you build your symbol
table without elaborating the design?

 

[KJ]

Particularly, parser works at per-file basis. Yet, file may refer

objects defined in another file (package), which parser have no idea of.

"which parser have no idea of"...That is not correct

Only elaborator is aware of their nature. How do you build your symbol

table without elaborating the design?

- In one word 'library'.
- In two questions to guide the reader to the solution 'Where do you think the output of parsing the file ends up?' and 'What do you think then happens with that output?' Hint: The 'one word' will help you on both questions.

I would be more helpful, but your misstating what I did say and then your statement to me "That statement as it is is (sic) pure nonsense" when in fact it is correct leads me to make you do some work for yourself.

Kevin Jennings

 

[valtih1978]

Because parsing the language and actually running a sim (or building
a final bit stream to program a device) are separate task.

Thanks for even more nonsense.

The LRM has some rules. The "object code" or

LRM says that there is analyzis stage and elaboration, which check the
design semantics and bind the objects. Thanks for attributing all that
activity to the parser and ignoring any analysis/elaboration that
perform on top of it. Since I asked about the difference between parser
and elaboration, it makes a great sense to silence any
analysis/elaboration and lead astray to the higher level tasks. This
should be really convincing.