Continuing after a breakpoint both with single step and cont (but breakpoints still one-use)

src/debug_target/stopped_target.rs

@@ -30,20 +30,26 @@ impl StoppedTarget {
 		Ok(self.breakpoints.contains_key(&(rip - 1)))
 	}
 
-	pub fn cont(mut self) -> Result<RunningTarget, DebugError> {
+	fn breakpoint_remove_and_rewind(&mut self) -> Result<(), DebugError> {
 		let mut registers = self.get_registers()?;
-		if self.breakpoints.contains_key(&(registers.rip - 1)) { // We are on a breakpoint, we remove it
-			self = self.remove_breakpoint(registers.rip - 1)?;
-			registers.rip -= 1;
-			nix::sys::ptrace::setregs(self.pid, registers).map_err(PTraceError)?;
-		}
+		self.remove_breakpoint(registers.rip - 1)?;
+		registers.rip -= 1;
+		nix::sys::ptrace::setregs(self.pid, registers).map_err(PTraceError)?;
+		Ok(())
+	}
 
+	pub fn cont(mut self) -> Result<RunningTarget, DebugError> {
+		if self.on_breakpoint()? {
+			self.breakpoint_remove_and_rewind()?;
+		}
 		nix::sys::ptrace::cont(self.pid, None).map_err(PTraceError)?;
 		Ok(self.to_running())
 	}
 
-	pub fn stepi(self) -> Result<RunningTarget, PTraceError> {
-		todo!("Take into account breakpoints also for stepi");
+	pub fn stepi(mut self) -> Result<RunningTarget, DebugError> {
+		if self.on_breakpoint()? {
+			self.breakpoint_remove_and_rewind()?;
+		}
 		nix::sys::ptrace::step(self.pid, None).map_err(PTraceError)?;
 		Ok(self.to_running())
 	}
@@ -62,7 +68,7 @@ impl StoppedTarget {
 	}
 
 	#[cfg(target_endian = "little")] // With a bit more work it could be implemented on both architectures, but I only have little-endian computers 🤷
-	pub fn add_breakpoint(mut self, address: u64) -> Result<Self, DebugError> {
+	pub fn add_breakpoint(&mut self, address: u64) -> Result<(), DebugError> {
 		if self.breakpoints.contains_key(&address) {
 			return Err(DebugError::DuplicateBreakpoint { address });
 		}
@@ -72,18 +78,18 @@ impl StoppedTarget {
 		nix::sys::ptrace::write(self.pid, address as *mut c_void, new_content).map_err(PTraceError)?;
 
 		self.breakpoints.insert(address, target_byte);
-		Ok(self)
+		Ok(())
 	}
 
 	#[cfg(target_endian = "little")] // Same as add_breakpoint
-	pub fn remove_breakpoint(mut self, address: u64) -> Result<Self, DebugError> {
+	pub fn remove_breakpoint(&mut self, address: u64) -> Result<(), DebugError> {
 		match self.breakpoints.remove(&address) {
 			None => Err(DebugError::NonExistingBreakpoint { address }),
 			Some(original_byte) => {
 				let content = nix::sys::ptrace::read(self.pid, address as *mut c_void).map_err(PTraceError)?;
 				let new_content = (content & (!0xff as c_long)) | (original_byte as c_long);
 				nix::sys::ptrace::write(self.pid, address as *mut c_void, new_content).map_err(PTraceError)?;
-				Ok(self)
+				Ok(())
 			}
 		}
 	}

src/main.rs

@@ -103,18 +103,20 @@ fn main() -> color_eyre::Result<()> {
 		Ok(ForkResult::Parent { child: child_pid }) => {
 			println!("✔️ Created child {child_pid}");
 
-			let target = StoppedTarget::new(child_pid)?;
+			let mut target = StoppedTarget::new(child_pid)?;
 			println!("✔️ Child ready!");
 
-			let target = target.add_breakpoint(0x401019)?;
+			let breakpoint1 = 0x401019;
+			println!("🛑 Adding breakpoint at {breakpoint1:#x}");
+			target.add_breakpoint(breakpoint1)?;
 			let target = target.cont()?.wait_for_something()?;
 			match target {
 				Either::Left(t) => {
-					println!("🔎 rip: {:#x}", t.get_registers()?.rip);
 					if t.on_breakpoint()? {
 						println!("🚧 We are on a breakpoint!")
 					}
-					t.cont()?.wait_for_exit()?;
+					println!("🔎 rip: {:#x}", t.get_registers()?.rip);
+					single_step_all(t)?;
 				}
 				Either::Right(ExitedTarget { exit_code, .. }) => {
 					println!("👋 Child exited with code {exit_code}");