verilator: add support for Verilator 4.228 (#126)

We can check VERILATOR_VERSION_INTEGER from include/verilated_config.h
for the numeric Verilator version (e.g., 4.228 becomes 4228000), so
there is no need for our own symbolic macros (e.g., VERILATOR_4_210).

This commit:
- replaces the usage of our newly defined macros and directly tests
  the VERILATOR_VERSION_INTEGER macro
- adds support for the VlThreadPool(...) signature used in 4.228 and
  newer of Verilator

Signed-off-by: Philipp Tomsich <[email protected]>

src/test/csrc/verilator/emu.cpp

@@ -734,7 +734,9 @@ void Emulator::snapshot_load(const char *filename) {
 
 void Emulator::fork_child_init() {
 #if EMU_THREAD > 1
-#ifdef VERILATOR_4_210
+#if VERILATOR_VERSION_INTEGER >= 4228000
+  dut_ptr->vlSymsp->__Vm_threadPoolp = new VlThreadPool(dut_ptr->contextp(), EMU_THREAD - 1);
+#elif VERILATOR_VERSION_INTEGER >= 4210000
   dut_ptr->vlSymsp->__Vm_threadPoolp = new VlThreadPool(dut_ptr->contextp(), EMU_THREAD - 1, 0);
 #else
   dut_ptr->__Vm_threadPoolp = new VlThreadPool(dut_ptr->contextp(), EMU_THREAD - 1, 0);

verilator.mk

@@ -42,9 +42,10 @@ endif
 
 # Verilator version check
 VERILATOR_VER_CMD = verilator --version | cut -f2 -d' ' | tr -d '.'
+VERILATOR_VERSION = $(shell `$(VERILATOR_VER_CMD)`)
+
 VERILATOR_4_210 := $(shell expr `$(VERILATOR_VER_CMD)` \>= 4210)
 ifeq ($(VERILATOR_4_210),1)
-EMU_CXXFLAGS += -DVERILATOR_4_210
 VEXTRA_FLAGS += --instr-count-dpi 1
 endif
 VERILATOR_5_000 := $(shell expr `$(VERILATOR_VER_CMD)` \>= 5000)