[difftest] remember cosim_init scope

difftest/online_dpi/src/dpi.rs

@@ -7,6 +7,7 @@ use std::sync::Mutex;
 use tracing::debug;
 
 use crate::drive::Driver;
+use crate::svdpi::SvScope;
 use crate::OfflineArgs;
 
 pub type SvBitVecVal = u32;
@@ -219,7 +220,9 @@ unsafe extern "C" fn t1_cosim_init() {
   let args = OfflineArgs::parse();
   args.common_args.setup_logger().unwrap();
 
-  let driver = Box::new(Driver::new(&args));
+  let scope = SvScope::get_current().expect("failed to get scope in t1_cosim_init");
+
+  let driver = Box::new(Driver::new(scope, &args));
   let mut dpi_target = DPI_TARGET.lock().unwrap();
   assert!(
     dpi_target.is_none(),
@@ -278,11 +281,11 @@ mod dpi_export {
 }
 
 #[cfg(feature = "trace")]
-pub(crate) fn dump_wave(path: &str) {
+pub(crate) fn dump_wave(scope: crate::svdpi::SvScope, path: &str) {
   use crate::svdpi;
   let path_cstring = CString::new(path).unwrap();
 
-  svdpi::set_scope_by_name("TOP.TestBench.clockGen");
+  svdpi::set_scope(scope);
   unsafe {
     dpi_export::dump_wave(path_cstring.as_ptr());
   }

difftest/online_dpi/src/drive.rs

@@ -7,6 +7,7 @@ use tracing::{debug, error, info, trace};
 
 use crate::dpi::*;
 use crate::get_t;
+use crate::svdpi::SvScope;
 use crate::OfflineArgs;
 
 struct ShadowMem {
@@ -97,6 +98,9 @@ impl ShadowMem {
 pub(crate) struct Driver {
   spike_runner: SpikeRunner,
 
+  // SvScope from t1_cosim_init
+  scope: SvScope,
+
   #[cfg(feature = "trace")]
   wave_path: String,
   #[cfg(feature = "trace")]
@@ -151,12 +155,13 @@ fn parse_range(input: &str) -> (u64, u64) {
 }
 
 impl Driver {
-  pub(crate) fn new(args: &OfflineArgs) -> Self {
+  pub(crate) fn new(scope: SvScope, args: &OfflineArgs) -> Self {
     #[cfg(feature = "trace")]
     let (dump_start, dump_end) = parse_range(&args.dump_range);
 
     let mut self_ = Self {
       spike_runner: SpikeRunner::new(&args.common_args, false),
+      scope,
 
       #[cfg(feature = "trace")]
       wave_path: args.wave_path.to_owned(),
@@ -269,7 +274,7 @@ impl Driver {
 
   #[cfg(feature = "trace")]
   fn start_dump_wave(&mut self) {
-    dump_wave(&self.wave_path);
+    dump_wave(self.scope, &self.wave_path);
   }
 
   pub(crate) fn step(&mut self) -> SpikeEvent {

difftest/online_dpi/src/svdpi.rs

@@ -1,5 +1,6 @@
-use std::{ffi::CString, ptr};
+use std::{ffi::{c_void, CString}, ptr::{self, NonNull}};
 
+#[rustfmt::skip]
 pub mod sys;
 
 /// get current simulation time in _simulation time unit_
@@ -27,3 +28,23 @@ pub fn set_scope_by_name(name: &str) {
     sys::svSetScope(scope);
   }
 }
+
+pub fn set_scope(scope: SvScope) {
+  unsafe {
+    sys::svSetScope(scope.ptr.as_ptr());
+  }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct SvScope {
+  ptr: NonNull<c_void>,
+}
+
+unsafe impl Send for SvScope {}
+
+impl SvScope {
+  pub fn get_current() -> Option<Self> {
+    let ptr = unsafe { sys::svGetScope() };
+    NonNull::new(ptr).map(|ptr| Self { ptr })
+  }
+}

difftest/online_dpi/src/svvpi.rs

@@ -1,3 +1,4 @@
+#[rustfmt::skip]
 pub mod sys;
 
 use std::ptr;