Drive strengths and delays are often handled as a pair of drive values
and a rise/fall/decay triple. Add small helper types to carry these
groups and use them in the continuous assignment and gate/UDP elaboration
paths.
Use the same helper types when propagating drive and delay values through
netlist links.
Also add helpers for dumping the values in debug output. This keeps the
behavior consistent and fixes one small bug where some of the debug
dumps printed the pointer value for the delays, rather than the actual
delay values.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
`pform_set_data_type()` is now only called on wires that already have the
correct wire type set. There is no need to pass the same type to
`pform_set_data_type()` and set it again.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows initialized and uninitialized net declaration entries to
be mixed in the same declaration, e.g. `wire x, y = 1'b1`. In Verilog,
either all nets need to have an initializer or non can have one.
In addition SystemVerilog also allows assignments to arrays of wires during
declaration. E.g. `wire a[3:0] = b;`
Currently there are two different rules for net declarations, one for each
of the Verilog variants. Combine these into a single rule to support
SystemVerilog mixed declarations as well as the assignment to array nets.
When running in Verilog mode still reject mixed initialized and
uninitialized with a check after the parsing.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The assignment handling block uses space-based indentation that does not match
the surrounding code.
Fix the indentation before changing the block.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog 2023 allows type parameters to be restricted to a
specific kind of type, e.g. `parameter type struct T = T0`.
This is very similar to the type restrictions that can be applied to
forward typedefs.
Factor the support code from the typedefs into a standalone helper and
reuse it for both.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Implement call_chain_expr in the parser, PECallFunction chain prefixes,
elaboration for class methods on returned handles, and prefix class resolution
for width checks on multi-hop chains. Place call_chain_expr before bare
hierarchy_identifier in expr_primary so id ( is not reduced as a lone ident.
Document behavior and developer notes in devel/sv_call_chain.md (including
that iverilog uses the installed lib/ivl/ivl binary).
Add ivtest sv_call_chain_method1 normal test with -g2012.
Made-with: Cursor
Enhance the lists of identifiers and declaration assignments generated
by the parser to associate each identifier with its lexical_pos. Also do
this for single items in complex parser rules where the location passed
to the pform is not the location of the identifier.
In addition to providing positional arguments for task and functions
SystemVerilog allows to bind arguments by name. This is similar to how
module ports can be bound by name.
```
task t(int a, int b); ... endtask
...
t(.b(1), .a(2));
```
Extend the parser and elaboration stage to be able to handle this. During
elaboration the named argument list is transformed into a purely positional
list so that later stages like synthesis do not have to care about the
names.
For system functions and tasks all arguments must be unnamed, otherwise an
error will be reported.
In addition to functions and tasks arguments can also be bound by name for
the various different ways of invoking a class constructor.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Attach line information to named items. This allows to provide better
location information for messages involving named items. The location of
item itself can't always be used, since the item itself might be empty.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
There are a few places in the code where a std::list is copied to a
std::vector by iterating through the list and copying each element over to
the vector. The std::vector type has a iterator based constructor that can
do the same.
Update the code to use it instead. This removes a bit of boilerplate code
and also makes it easier to update the code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
`named_pexpr_t` is a typedef for `named<PExpr*>`. There are a few places
where `named<PExpr*>` is used directly. Replace those with `named_pexpr_t`
for consistency.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows to declare const variables. These variables are
read-only and can not be assigned a value after their declaration. It is
only possible to assign an initial value as an initializer.
E.g.
```
const int x = 10;
x = 20; // Error
```
The LRM requires that for variable declarations with static storage the
initializer is a constant expression with the extension that other const
variables are also allowed. const variables with automatic storage can
be initialized by any expression.
Checking if an expression contains only const variables requires a bit more
work to implement. So for now be more lenient that what the standard
requires and allow arbitrary expressions to initialize const variables even
for those with static storage.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
`ivl_assert()` is similar to `assert()` except that it will also include
source file and line information about the expression for which the assert
was triggered.
Use `ivl_assert()` instead of `assert()` where the line information is
available. This will generate better bug reports and make it easier to
diagnose why an assert is triggered.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog requires that functions and tasks are not implicitly imported
if a symbol with the same name appears in the scope, even if it the symbol
is declared after its usage.
To support this a list of potential imports is collected while parsing a
scope and only when the end of the scope is reached it is evaluated whether
the symbol should be imported or not based on whether it already exists in
the scope.
This currently works fine for all scopes except for the unit scope. Since
the unit scope might span multiple files it is never explicitly closed and
the potential imports are never checked.
Make sure that after parsing all files is done the potential imports for
the unit scope are checked.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
By default an identifier that has been imported into a package is not
available for imports by other packages. Only imports that have been
exported can be imported again. E.g.
```
package P1;
int x;
endpackage
package P2;
import P1::x;
export P1::x;
endpackage
module test;
import P2::x; // This will only work if x has been exported.
endmodule
```
Exports follow the same syntax as imports and allow both export of specific
identifiers or wildcard export. Export supports the special `*::*` target,
which will export all imported items.
Add support for handling package exports.
There is one special cases that needs to be considered. Usually when using
wildcard imports from multiple packages it is an error if there multiple
import candidates for an identifier. With exports it is possible that there
are multiple candidates through different packets, but they all refer to
the same identifier. In this case it does not create a conflict. E.g.
```
package P1;
int x;
endpackage
package P2;
import P1::x;
export P1::x;
endpackage
package P3;
import P1::*;
import P2::*;
int y = x; // No import conflict
endpackage
```
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
One variant did, the other variant didn't. As well as being a trap for
the unwary, this gets in the way of using yywarn/VLwarn for non-fatal
"sorry" messages.
Up to 1800-2017 the grammar in the LRM allowed an optional lifetime
qualifier for class declarations. Icarus supports this and uses this as the
default lifetime for methods of the class. But the LRM never specified what
this qualifier should do actually actually. Starting with 1800-2023 the
qualifier will be removed from the grammar[1].
Furthermore the LRM states that methods of a class are supposed to have
automatic storage and static storage is forbidden.
This currently works in Icarus for the most part since the liftime attached
to class methods is ignored during elaboration in most places. Where it
does not work is for variable initializers where it results in broken code
being generated and vvp crashes at runtime. E.g.
```
class C;
task t;
int x = 10;
endtask
endclass
```
Keep the optional lifetime qualifier for classes in the grammar for now, to
ensure backwards compatibility in case somebody is actually using it. But
ignore it and print a warning if it is specified.
In addition set the default lifetime for all classes to automatic. This
makes sure that variable initialization in classes works as expected.
[1] https://accellera.mantishub.io/view.php?id=3561
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Clean up warnings that show up on newer compilers. Many of these warnings
are related to obsolete c library features or language features. This does
not clear up warnings in code generated by bison or flex.
With the recent refactorings pform_make_task_ports_vec() and
do_make_task_ports() are now very similar.
Consolidate them into a single function.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The ivl_variable_type_t in PWire is now only used for passing the base type
for vector types to the elaboration stage. But we can query the base the
from the vector_type_t itself. If the there is no data_type_t set for the
PWire the base type will default to IVL_VT_LOGIC.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows to skip dimensions in a foreach loop by not specifying
an identifier name for the dimensions. E.g. the following will iterate over
the first and last dimensions, but skip the middle dimension.
```
int x[1][2][3];
foreach(x[a,,b]) ...
```
Add support for this to the parser as well as elaboration.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog supports type parameters. These are similar to value
parameters, but they allow to pass a type to a module or similar when
instantiating it.
E.g.
```
module A #(parameter type T = int);
endmodule
module B;
A #(.T(real)) i_a;
endmodule
```
Add support for handling type parameters.
For the vlog95 and vhdl backends type parameters, similar to typedefs, get
replaced with their actual value. For modules with non-local type
parameters for each module instance a unique module or architecture is
generated with the actual type.
Querying type parameters through VPI is not yet supported.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cary R.
Lars-Peter Clausen
Jose Tejada
mjoekhan
Martin Whitaker
mole99
Stephen Williams
Stephen Williams