If a net or variable is referenced in another net or variable declaration
or in a value parameter definition (e.g. when using the $bits function)
and hasn't already been elaborated, we need to elaborate it early. So
during the scope elaboration phase, add placeholders in each NetScope
object to record the PWire objects that are yet to be elaborated. This
allows the symbol_search() function to find the unelaborated objects
and to trigger early elaboration.
Add a flag in the PWire object to indicate when we are elaborating it.
This allows us to detect circular references and avoid an infinite loop.
This fixes issue #483, issue #575, and issue #1097.
This only applies to simple identifiers. Only return a match if the
lexical position of the identifier being searched is later in the
source text than the lexical position of a matching symbol.
`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>
Package scoped identifiers should only be able to access identifiers that
are declared in the package, but not identifiers that are visible in the
package, but declared outside of it.
```
int x;
package P;
int y;
endpackage
module test;
initial begin
$display(P::x); // Should fail
$display(P::y); // OK
end
endmodule
```
Make sure that the symbol search will not attempt to cross the package
boundary during identifier lookup.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
In SystemVerilog identifiers can usually have an additional package scope
in which they should be resolved. At the moment there are many places in
the code base that handle the resolution of the package scope.
Add a common data type for package scoped paths as well as a
symbol_search() variant that works on package scoped identifiers. This
allows to handle package scope resolution in a central place.
Having the code in a central place makes it easier to ensure consistent and
correct behavior. E.g. there are currently some corner case bugs that are
common to all implementations. With the common implementation it only has
to be fixed in one place.
It will also make it easier to eventually implement class scoped
identifiers.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
There are currently two mechanisms for handling class properties. One that
is used when a class property is accessed through an object and other when
a class property is used freestanding in a class method.
Both are very similar, but there are some small differences. E.g. one
supports arrays, the other supports nested properties.
```
class B;
int x;
endclass
class C;
B b;
B ba[2];
task t;
ba[0] = new; // Does work
this.ba[0] = new; // Does not work
b.x = 10; // Does not work
this.b.x = 10; // Does work
endtask
```
There is another problem where free standing properties take precedence
over local variables. E.g.
```
class C;
int x = 1;
task t();
int x = 2;
$display(x); // Should print 2, will print 1
endtask
endclass
```
The class property elaboration also ignores the package scope of the
identifier resulting in access to a class property being elaborated if
there is a property of the same name as the scoped identifier. E.g.
```
package P;
int x = 2;
endpackage
class C;
int x = 1;
task t;
$display(P::x); // Should print 2, will print 1
endtask
endclass
```
Consolidate the two implementation to use the same code path. This is
mainly done by letting the symbol search return a result for free standing
properties as if the property had been specified on the `this` object. I.e.
`prop` and `this.prop` will return the same result from the symbol search.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
There are no users of the old symbol_search that need the cls_val result.
Remove it as a output parameter of the function.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Imported identifiers should only be visible in the scope they have been
imported too. They should not be accessible through hierarchical names into
that scope. This is defined in section 26.3 ("Referencing data in
packages") of the LRM (1800-2017).
Modify the symbol search to not look at imports if the name is part of a
hierarchical path.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows to use the `super` keyword to access properties and
methods of a base class. This is useful if there is for example an
identifier with the same name in the current class as in the base class and
the code wants to access the base class identifier.
To support this a bit of refactoring is required. Currently properties are
internally referenced by name, this does not work if there are multiple
properties of the same. Instead reference properties always by index.
In addition when looking up an identifier that resolves to an object return
both the type and the object itself. This is necessary since both `this`
and `super` resolve to the same object, but each with a different type.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
There are too many ad hoc handlers of symbol_search partial results.
Rewrite symbol_search to clean up things like partial results and
member/method detections. Use this reworked symbol_search function
to rewrite expression elaborate for the PECallFunction expressions.
Use the common data_type_or_implicit rules to support type
definitions for parameters. This eliminates a bunch of special
rules in parse.y, and opens the door for parameters having
more complex types.
The compilation unit scope is now treated as a specialised form of
package (with an automatically generated name). All items declared
outside a design element are added to the current compilation unit
package. Apart from when searching for a symbol, once we get into
elaboration we can treat these just like any other package.
Making the scope type NESTED_MODULE was just plain wrong, because
it didn't really encapsulate the meaning of program blocks OR
nested modules. So instead create nested_module() and program_block()
flags and use those to test scope constraints.
The compiler currently performs parameter expression elaboration before
performing parameter overrides. This means that the information needed
to correctly determine the expression type and width may not be available
at the time elaboration is performed. This patch reworks the code to
delay elaboration until after all overrides have been performed. It
also provides a new -g option that controls how the width of parameter
expressions is calculated when the parameter itself is unsized.
The functions (malloc, free, etc.) that used to be provided in
malloc.h are now provided in cstdlib for C++ files and stdlib.h for
C files. Since we require a C99 compliant compiler it makes sense
that malloc.h is no longer needed.
This patch also modifies all the C++ files to use the <c...>
version of the standard C header files (e.g. <cstdlib> vs
<stdlib.h>). Some of the files used the C++ version and others did
not. There are still a few other header changes that could be done,
but this takes care of much of it.
When searching for a symbol we do not want to search up the
hierarchical stack if the symbol we are searching for was
prefixed with a hierarchical path.
Remove the #ident and $Log$ strings from all the header files and
almost all of the C/C++ source files. I think it is better to get
this done all at once, then to wait for each of the files to be
touched and edited in unrelated patches.
This patch splits any VVP net functor that needs to access both
statically and automatically allocated state into two sub-classes,
one for handling operations on statically allocated state, the
other for handling operations on automatically allocated state.
This undoes the increase in run-time memory use introduced when
automatic task/function support was first introduced.
This patch also fixes various issues with event handling in automatic
scopes. Event expressions in automatic scopes may now reference either
statically or automatically allocated variables or arrays, or part
selects or word selects thereof. More complex expressions (e.g.
containing arithmetic or logical operators, function calls, etc.) are
not currently supported.
This patch introduces some error checking for language constructs
that may not reference automatically allocated variables. Further
error checking will follow in a subsequent patch.
Better handle cases where the scope part of a heirarchical name does
not match any existing scope, or where scope index expressions are
not correct.
Signed-off-by: Stephen Williams <steve@icarus.com>
more general concept of arrays. The NetMemory and NetEMemory
classes are removed from the ivl core program, and the IVL_LPM_RAM
lpm type is removed from the ivl_target API.
Martin Whitaker
Lars-Peter Clausen
Cary R
Stephen Williams
Larry Doolittle
Arun Persaud
Martin Whitaker
Martin Whitaker
steve