[SOLVED] Using Verilator with CMake when RTL uses a SV package

Using Verilator with CMake when RTL uses a SV package

I´m trying to port a Verilator TB from Make to CMake. My CMakeLists looks like this:

add_executable(example ./src/my_tb.cpp)

list(APPEND rtl_sources ../rtl/some_pkg.sv ../rtl/some_module.sv ../rtl/top_core.sv)

verilate(example
  VERILATOR_ARGS -Wall --Wno-fatal --sv
  INCLUDE_DIRS "./src"
  SOURCES ${rtl_sources}
  TOP_MODULE top_core)

When I run this, the verilate command ignores the TOP_MODULE parameter and creates "Vsome_pkg.h" and related files. This means that my cpp TB will not build, because it expects to include "Vtop_core.h".

I cannot move top_core.svto the head of the filelist because it uses the package; the filelist needs to reflect the RTL dependencies, as far as I can tell, otherwise verilate fails.

In the Make version of mt TB, I invoke verilate with --top top_core and it all works just fine.

My verilator version is 5.018 and the Verilator reference documentation I´m using is for 5.017.
Also, I made a few experiments and TOP_MODULE fails if I use a non-existent module name, so it definitely is being read by the verilate command; yet somehow it´s being ignored.

I am a complete newcomer to CMake (I started the port today because I need to improve my TB with C++ libraries that in practice demand CMake) so I am pretty sure I am missing something basic.

Any help in spotting what I´m missing will be greatly appreciated!

SUMMARY: I expected the verilate command to use my TOP_MODULE argument and generate "Vtop_core.h" and related files.

Instead, it apparently ignored TOP_MODULE and used the first element of SOURCES as top module.

UPDATE: I just noticed that the executed command line for verilate looks like this:

Verilator command: "/ucrt64/bin/verilator_bin.exe --compiler gcc --prefix Vsome_pkg 
--Mdir [...]/build/CMakeFiles/example.dir/Vsome_pkg.dir 
--make cmake --top top_core --cc 
-y ./src -Wall --Wno-fatal 
../rtl/some_pkg.sv ../rtl/some_module.sv ../rtl/top_core.sv"

(newlines added for readability)

So the --top argument is included in the command, but it can´t override the --Mdir and --prefix arguments.
More comments to follow as I do a few trials...

FURTHER UPDATE

If I add this to my verilate command

PREFIX Vtop_core

...then the whole thing works; verilate creates the Vtop_core.h and related files and the build now fails for a different and probably unrelated reason.

So this change fixes my problem. But it looks kinda hacky.

I´ll do a few more trials and will auto-respond this question later on, but if anyone can shed any light on this, it will help me a lot!

Solution

Adding parameter PREFIX Vtop_core to the verilate command fixes the issue.

I am pretty sure this is not the canonic way to use SV packages in a CMake-enabled Verilator TB but it works.