fix(debugger):

- usize overflow in `Unit::find_place_by_pc`
- `next` step now takes into account that the debugee can finish execution while stepping

src/debugger/debugee/dwarf/unit/mod.rs

@@ -521,7 +521,7 @@ impl Unit {
         let pc = u64::from(pc);
         let pos = match self.lines.binary_search_by_key(&pc, |line| line.address) {
             Ok(p) => p,
-            Err(p) => p - 1,
+            Err(p) => p.saturating_sub(1),
         };
 
         self.find_place_by_idx(pos)

src/debugger/step.rs

@@ -3,7 +3,7 @@ use crate::debugger::breakpoint::Breakpoint;
 use crate::debugger::debugee::dwarf::unit::PlaceDescriptorOwned;
 use crate::debugger::debugee::tracer::{StopReason, TraceContext};
 use crate::debugger::{Debugger, ExplorationContext};
-use anyhow::anyhow;
+use anyhow::{anyhow, bail};
 use nix::sys::signal::Signal;
 
 /// Result of a step, if [`SignalInterrupt`] then step process interrupted by a signal and user must know it.
@@ -331,14 +331,17 @@ impl Debugger {
                 .debug_info(new_location.pc)?
                 .find_place_from_pc(new_location.global_pc)?
                 .ok_or_else(|| anyhow!("unknown function range"))?;
-
             if place.address != new_location.global_pc {
                 if let StepResult::SignalInterrupt { signal, .. } = self.step_in()? {
                     return Ok(StepResult::signal_interrupt(signal));
                 }
             }
         }
 
+        if self.debugee.is_exited() {
+            bail!("debugee exited while step execution");
+        }
+
         self.expl_ctx_update_location()?;
         Ok(StepResult::Done)
     }