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.
The function prototypes both use the name VLwarn, with a macro definition
providing the alias to yywarn. But one of the variant implementations was
named yywarn. Make it consistent with the function prototype.
Always prefix with "error: ". Capitalise the first word of the main
message unless it's a Verilog keyword. Use VLerror() in preference
to direct output to cerr.
Check that typed constructors calls are supported. Also check various
invalid usages of typed constructor calls and check that an error is
reported.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
By default when creating a new class object the type of the object is
determined by the type of the target.
SystemVerilog also allows to explicitly specify the type of the object to
be created. The specified class still needs to be assignment compatible
with the target. This is e.g. useful to construct an object of a derived
class of the target. E.g.
```
class B; ... endclass
class C extends B; ... endclass
B b;
b = C::new;
```
Add support for this to the parser as well as handling it during
elaboration.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Class methods with static lifetime are not allowed in SystemVerilog. Report
an error when such a method is declared.
Note that this is different from static class methods
E.g.
```
class C;
task static t; endtask // Class method with static lifetime, forbidden
static task t; endtask // Static class method, allowed
```
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
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>
Normally the preprocessor will catch these and report them as undefined
macros. But in case the compiler is run without the preprocessor, also
catch them in the compiler scanner. This will ensure the scanner properly
rejects directives that have additional garbage characters tacked on the
end.
Verilog compiler directives are free-form and, subject to semantic rules,
can appear anywhere in the source code. Whilst it is common practice to
write them on a separate line, we should handle all legal syntax.
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.
It was common practice in the past to just declare a port direction
and declare it as a vector in a subsequent type declaration. Versions
of the standard up to and including 1364-2005 include an example that
does this (e.g. 1364-2005 section 12.3.7). Users may have old or
third-party code that they can't or don't want to modify, so allow
the warning to be suppressed by including it in the anachronisms
category.
Check various different scenarios for array compatibility in continuous
array assign. Both testing cases that should work and cases that should
fail.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently there is no error checking for continuous assignments to unpacked
arrays. If the lvalue and rvalue net are not compatible undefined behavior
occurs. For some types of incompatibility it will crash during elaboration,
for others it will crash during simulation, and for some it will just work,
even though the assignment is not allowed by the standard.
Implement checking to ensure the two nets are compatible as required by the
standard and report an error otherwise.
Two arrays are considered to be compatible if their element types are
equivalent, they have the same number of ranges and each range has the same
number of elements.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that it is possible to assign an object to another object that is of
a type of any of its base classes. Also check that an error is reported if
this is not the case.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows objects to be assigned to a variable that is a base
type of the objects type.
E.g.
```
class B; endclass
Class C extends B; endclass
C c = new
B b = c;
```
Add a type_compatibility() method for netclass_t that allows these kinds of
assignments.
This already works fine in vvp since, as SystemVerilog does not support
multiple inheritance, properties will always be at the same offset in the
base class and the inheriting class.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that it is possible to use a function with a return type as a
statement by using a void cast.
Also check that trying to void cast a void function, a task or an
expression results in an error.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog has explicit support for calling a function
as a statement. This is allowed when the function call is encapsulated in
`void'(...)`. E.g. `void'(f(1, 2, 3));`
We already support calling function calls as statements without the void
cast and emit a warning when doing so.
Adding support for void casts only requires to update the parser to handle
the void cast and then do not emit the warning if a function is called as
a statement as part of a void cast.
Void casting a task or void function call is not allowed and will generate
an elaboration error.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
When calling non-void functions or non-void methods of built-in types as a
task a warning is issued. But when calling a non-void method of a user
defined class as a task an error is generated.
Be consistent here and generate a warning in both cases.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Unpacked array dimensions that are specified with only a single size value
(C-style unpacked arrays) have a $left of 0 and a $right of size - 1. E.g.
`x[10]` is equivalent to `x[0:9]`. This is defined in the LRM (1800-2017)
section 7.4.2 ("Unpacked arrays").
Currently it is implemented the other way around. There are a few contexts
where this distinction matters. For example array to array assignments,
which are supposed to be done left-to-right.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that an error is reported when either calling a task or a void
function as part of an expression.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Calling a task as part of an expression should report an error. The current
implementation uses `func_def()` and if that returns nullptr will report
the error. But `func_def()` will trigger an assert if the underlying scope
is not a function.
Make sure to first check that the scope is actually a function before
trying to call `func_def()`. If the scope is not a function report an
error.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Unlike normal functions void functions can not be called as part of an
expression. Trying so will currently hit an internal assert.
Make sure an error is reported instead.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
It is not allowed to create objects of virtual classes. Currently the
virtual keyword is accepted by the parser, but otherwise ignored.
Keep track of whether a class is virtual and generate an error when the
class new operator is used for a virtual type.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that a sign, width or type cast expression that contains an automatic
term is detected as such and can not be used as the left-hand side in a
procedural continuous assignment.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Stephen Williams
Martin Whitaker
Lars-Peter Clausen
Stephen Williams