Cleaned up compilation handling for yosys-slang when parmys is turned off

Author: loglav03

.github/workflows/test.yml

@@ -96,7 +96,7 @@ jobs:
 
     - name: Build
       env:
-        CMAKE_PARAMS: "-DCMAKE_COMPILE_WARNING_AS_ERROR=on -DVTR_IPO_BUILD=off -DVTR_ASSERT_LEVEL=3 -DWITH_BLIFEXPLORER=on -DWITH_PARMYS=OFF -DSLANG_SYSTEMVERILOG=OFF -DWITH_ODIN=on"
+        CMAKE_PARAMS: "-DCMAKE_COMPILE_WARNING_AS_ERROR=on -DVTR_IPO_BUILD=off -DVTR_ASSERT_LEVEL=3 -DWITH_BLIFEXPLORER=on -DWITH_PARMYS=OFF -DWITH_ODIN=on"
         BUILD_TYPE: release
         NUM_PROC: ${{ steps.cpu-cores.outputs.count }}
       run: |
@@ -456,7 +456,7 @@ jobs:
         include: [
           {
             name: 'Basic',
-            params: '-DVTR_ASSERT_LEVEL=3 -DVTR_ENABLE_SANITIZE=on -DVTR_IPO_BUILD=off -DWITH_BLIFEXPLORER=on -DWITH_PARMYS=OFF -DSLANG_SYSTEMVERILOG=OFF -DWITH_ODIN=on',
+            params: '-DVTR_ASSERT_LEVEL=3 -DVTR_ENABLE_SANITIZE=on -DVTR_IPO_BUILD=off -DWITH_BLIFEXPLORER=on -DWITH_PARMYS=OFF -DWITH_ODIN=on',
             suite: 'vtr_reg_basic_odin'
           }
           #- { name: 'Strong', suite: 'vtr_reg_strong' } # SKIP Too long to run on GitHub Actions (max 6h)

CMakeLists.txt

@@ -437,11 +437,12 @@ if(${WITH_ODIN})
     endif()
 endif()
 
-# handle cmake params to compile Yosys SystemVerilog/UHDM plugins
+# handle cmake params to compile yosys-slang plugin for Yosys
 if(${SLANG_SYSTEMVERILOG})
-    # avoid compiling plugins in case the Parmys frontend is not active
+    # avoid compiling yosys-slang plugin in case the Parmys frontend is not active
     if(NOT ${WITH_PARMYS})
-        message(SEND_ERROR "Utilizing SystemVerilog/UHDM plugins requires activating Parmys frontend. Please set WITH_PARMYS.")
+        message(WARNING "Parmys is not enabled, disabling Yosys-Slang as well.")
+        set(SLANG_SYSTEMVERILOG OFF)
     endif()
 endif()