[Iverilog-devel] Initalizers for constants in packages

[Maciej S. <mac...@ce...>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi Steve,

I have managed to solve the problem of elaboration of constants
initializers in packages, so there is a new pull request [1]. I have
prepared tests too, but as we have recently agreed - I will merge them
to the test suite repository as soon as the iverilog changes are merged.
Now, I would like to implement elaboration for aggregate expressions
that serve as record initializers. To illustrate:

- --- VHDL version ---
library ieee;
use ieee.std_logic_1164.all;

entity foo_entity is
end foo_entity;

architecture test of foo_entity is

type word is record
  high: std_logic_vector (3 downto 0);
  low: std_logic_vector (3 downto 0);
end record;

signal my_word: word := (high => "0100", low => "0110");

begin
  my_word <= (high => "0100", low => "0110");
end test;

- --- SystemVerilog version ---
module foo_entity;
typedef struct packed {logic[3:0] high; logic[3:0] low;} word;
wire word my_word = {4'b0100, 4'b0110};                // 1
//assign my_word = '{4'b0100, 4'b0110};                // 2
//assign my_word = '{ high: 4'b0100, low: 4'b0110 };   // 3
assign my_word  = {4'b0100, 4'b0110};                  // 4

endmodule

The SystemVerilog-2012 standard says that assignment and
initialization should be done in the way marked with "// 2". I have
seen in a few places that it can be assigned like in "// 3", but could
not find an excerpt in the standard that allows it.
Icarus currently accepts and correctly executes initalization &
assignment using the method shown in "// 1" and "// 4". Do you agree
that I implement it that way in vhdlpp? Later it could be easily
changed - it needs just one apostrophe to be added.

By the way: I am wondering why e.g. variable names outputted by vhdlpp
are prefixed with '\'?

Regards,
Orson

[1] https://github.com/steveicarus/iverilog/pull/42
[2] https://github.com/orsonmmz/ivtest/tree/const_package_test
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2

iQEcBAEBAgAGBQJUFwhjAAoJEBRwGu1hpbJ1ocsH/RuPYVe9kLzAbumPCud8k+aY
Zc4jmIPdD46IfG1XijXoISZIegmT+FWZP/IAsmMCSSfCV+qIAyivQ8nZr/ITL9AV
ccAGAYcmcTVlibBrTImcHaLlHm+wb8vgZOwCgXXLD6bb3etKpgV5GJoSBa1J6WxT
3DLksoSYqtC4lzMv5JpbefW1RUD9ZEpbwEEgWSppHNZBhGX0aMMrHArW6sEn6558
OMvDwOZg50+MLB8YOZqZEQ8FE3K5oFXDwRCUqgCqfr3GTwKxLiel1mCiupTNDRMv
t8OKYTo45oBFgFxmdWVIdEFaO6AYthWXU5qgfEKAGr3kkWDntnfr+G4BGTuTGOA=
=0nzK
-----END PGP SIGNATURE-----