Compiler can't resolve name conflict

[Michael Eichler]

Hello,

In the small example below both Modelsim and NCSim do complain about the
type of p3 in the line

b_out(bus_names'pos(p3)) <= p3;

Modelsim Error Message:
** Error: ../test_name_conflict.vhd(34): Signal "p3" is type std_ulogic;
expecting type bus_names.

But the required argument type is known to the compiler (bus_names) and
is visible. So the correct object could be selected by the compiler (p3
of enum bus_names instead of the port p3). Are the compilers wrong or
did I miss something important?


-- ******************************************************************

PACKAGE name_conflict_pkg IS

TYPE bus_names IS (b1, b2, p3);

END name_conflict_pkg;


LIBRARY IEEE;
USE IEEE.std_logic_1164.ALL;
LIBRARY work;
USE work.name_conflict_pkg.ALL;

ENTITY test_name_conflict IS

PORT (p1 : IN std_ulogic;
p2 : IN std_ulogic;
p3 : IN std_ulogic;
b_out : OUT std_ulogic_vector(bus_names'pos(bus_names'high)
DOWNTO
bus_names'pos(bus_names'low)));

END test_name_conflict;

ARCHITECTURE test OF test_name_conflict IS

BEGIN -- test

b_out(bus_names'pos(b1)) <= p1;
b_out(bus_names'pos(b2)) <= p2;

-- Why is this an name conflict with Port p3?
-- Type of required argument is known to the compiler
-- See LRM 1076-1993 Section 10; Rule 255 ??
b_out(bus_names'pos(p3)) <= p3;

-- This will work:
-- b_out(bus_names'pos(bus_names'high)) <= p3;

END test;
-- ******************************************************************

 

[john Doef]

Michael Eichler a écrit :

Hello,

In the small example below both Modelsim and NCSim do complain about the
type of p3 in the line

b_out(bus_names'pos(p3)) <= p3;

Modelsim Error Message:
** Error: ../test_name_conflict.vhd(34): Signal "p3" is type std_ulogic;
expecting type bus_names.

But the required argument type is known to the compiler (bus_names) and
is visible. So the correct object could be selected by the compiler (p3
of enum bus_names instead of the port p3). Are the compilers wrong or
did I miss something important?
You miss something.

The only possible meaning of p3 is the port p3. When the port is
declared, it makes
the p3 literal not visible anymore. You could use name_conflict_pkg.p3

JD.