Author Name: Matt Myers
Original Redmine Issue: 1149 from https://www.veripool.org

The attached example shows a localparam assigned by a constant function which returns a nested struct.

The code results in the following Verilator error:

%Error: Internal Error: ../V3Number.cpp:641: toUQuad with 4-state 32'bxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

There are two tweaks that cause the code to work:

1. Get rid of the nested struct (`define USE_FLAT), or
2. Keep the nested struct but leave only 1 element in the nested struct (`define ONE_FIELD)

In a larger system, this incompatibility is not actually causing a compile error, but it is causing a problem where a generate statement that uses this nested struct field as an upper bound on a for loop is not iterating properly. I got this Internal Error when trying to create a small test case.

Run the test with:
verilator +1800-2012ext+sv -Wall --cc struct_param.sv --exe sim_main.cpp --top-module struct_test; make -j -C obj_dir -f Vstruct_test.mk Vstruct_test; obj_dir/Vstruct_test