In traditional Verilog, each task_port_item must have an explicit port
direction.
In SystemVerilog, if the port direction is not specified, it should be
inherited from the preceding task_port_item for that task/function, and
only the first task_port_item should infer the direction to be 'input'.
Predefined macros get stored in the precompiled macro file that gets
read back in when processing library files. This means the predefined
macros get processed twice. We need to skip the check in this case.
A common use case (prior to the introduction of localparam) was to
use macros to define constant values, and to put global constant
values in an include file that gets included by each source file.
This will generate a lot of spurious warnings if we warn about all
redefinitions. Make this new option the default for -Wall.
In vvp, the __vpiSignal object holds a pointer to the scope containing
the signal. This was getting set to the current scope when the net was
finally resolved, rather than to the scope where the net was declared.
This implements and enforces the full set of rules for determining
timescales in SystemVerilog. The previous relaxation of the rules
that allowed timescales to be redefined within the compilation unit
scope has been removed. Time unit and precision redeclarations are
now recognised after a nested module declaration.
This relies on using the automatically generated name for the unit scope.
This could collide with an escaped identifier, so it would be better to
identify the scope by a reference to the PPackage object, but for now,
do it the easy way.
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.
This adds a -u option to the driver to allow the user to specify that
they want each source file to be treated as a separate compilation
unit, and modifies the compiler to accept a list of files (either on
the command line or via a file specified by a new -F option). This
list of files is then preprocessed and parsed separately, causing all
compiler directives (including macro definitions) to only apply to the
file containing them, as required by the SystemVerilog standard.
Martin Whitaker
Cary R
Stephen Williams
Scott Mansell