[difftest] add rtl unexcepted quit check in difftest

[difftest] refactor dpi_pre_link.cc to use std::shared_ptr for VerilatedContext and deal with chisel error

[difftest] use return code instead of panic when exiting offline difftest

[difftest] fix wrong unique ptr usage

difftest/offline/src/difftest.rs

@@ -41,7 +41,7 @@ impl Difftest {
       JsonEvents::SimulationStop { reason, cycle } => {
         info!("simulation stopped at cycle {}, reason {}", cycle, reason);
         self.runner.cycle = *cycle;
-        Ok(())
+        Err(anyhow::anyhow!("quit: no more events"))
       }
       JsonEvents::Issue { idx, cycle } => {
         self.runner.cycle = *cycle;

difftest/offline/src/dut.rs

@@ -39,7 +39,7 @@ impl Dut {
   pub fn step(&mut self) -> anyhow::Result<&JsonEvents> {
     let event = match self.events.get(self.idx as usize) {
       Some(event) => event,
-      None => return Err(anyhow::anyhow!("no more events")),
+      None => return Err(anyhow::anyhow!("error: rtl quit unexpectedly")),
     };
     self.idx += 1;
 

difftest/online_drive/dpi_c/dpi_pre_link.cc

@@ -1,23 +1,24 @@
 #include <VTestBench.h>
 #include <VTestBench__Dpi.h>
+#include <memory>
 
 class VTestBench;
 
-static VerilatedContext *contextp;
-static VTestBench *topp;
+static std::unique_ptr<VerilatedContext> contextp;
+static std::unique_ptr<VTestBench> topp;
 
 extern "C" int verilator_main_c(int argc, char **argv) {
   // Setup context, defaults, and parse command line
   Verilated::debug(0);
-  contextp = new VerilatedContext();
+  contextp = std::make_unique<VerilatedContext>();
   contextp->fatalOnError(false);
   contextp->commandArgs(argc, argv);
 #ifdef VM_TRACE
   contextp->traceEverOn(true);
 #endif
 
   // Construct the Verilated model, from Vtop.h generated from Verilating
-  topp = new VTestBench(contextp);
+  topp = std::make_unique<VTestBench>(contextp.get());
 
   // Simulate until $finish
   while (!contextp->gotFinish()) {
@@ -31,14 +32,17 @@ extern "C" int verilator_main_c(int argc, char **argv) {
 
   if (!contextp->gotFinish()) {
     VL_DEBUG_IF(VL_PRINTF("+ Exiting without $finish; no events left\n"););
+    return 1;
+  }
+
+  if (contextp->gotError()) {
+    VL_DEBUG_IF(VL_PRINTF("+ Exiting due to errors\n"););
+    return 1;
   }
 
   // Final model cleanup
   topp->final();
 
-  delete topp;
-  delete contextp;
-
   return 0;
 }
 

difftest/online_drive/src/dpi.rs

@@ -5,7 +5,7 @@ use clap::Parser;
 use std::ffi::{c_char, c_int, c_longlong, CString};
 use std::ptr;
 use std::sync::Mutex;
-use tracing::debug;
+use tracing::{debug, error};
 
 use crate::drive::Driver;
 use crate::OfflineArgs;
@@ -280,7 +280,7 @@ pub(crate) fn get_t() -> u64 {
   unsafe { get_t_c() / 20 }
 }
 
-pub(crate) fn verilator_main() {
+pub(crate) fn verilator_main() -> i32 {
   let c_args: Vec<CString> = std::env::args().map(|arg| CString::new(arg).unwrap()).collect();
 
   let mut c_args_ptr: Vec<*const c_char> = c_args.iter().map(|arg| arg.as_ptr()).collect();
@@ -289,12 +289,16 @@ pub(crate) fn verilator_main() {
   let argc = c_args.len() as c_int;
   let argv = c_args_ptr.as_ptr() as *mut *mut c_char;
 
-  unsafe {
-    verilator_main_c(argc, argv);
+  let verilator_ret = unsafe { verilator_main_c(argc, argv) };
+
+  if verilator_ret == 0 {
+    std::fs::write("perf.txt", format!("total_cycles: {}", get_t()))
+      .expect("fail to write into perf.txt");
+  } else {
+    error!("verilator_main_c return unexpectedly");
   }
 
-  std::fs::write("perf.txt", format!("total_cycles: {}", get_t()))
-    .expect("fail to write into perf.txt");
+  verilator_ret
 }
 
 #[cfg(feature = "trace")]

difftest/online_drive/src/main.rs

@@ -23,5 +23,5 @@ pub(crate) struct OfflineArgs {
 }
 
 fn main() {
-  verilator_main();
+  std::process::exit(verilator_main());
 }