From 673c1e4d07a04c3f6429c6cedb70610e3afd962e Mon Sep 17 00:00:00 2001
From: Rene Gollent <anevilyak@gmail.com>
Date: Sun, 11 Dec 2011 22:26:43 -0500
Subject: [PATCH] Fix step out for recursive functions.

When asked to step out, we now store the frame pointer of the current
stack frame. Upon hitting our temporary breakpoint, we then verify that
the current frame pointer is in fact in the previous frame. If not, we
reinstate the breakpoint and continue running.
---
 src/apps/debugger/ThreadHandler.cpp | 29 ++++++++++++++++++++++-------
 src/apps/debugger/ThreadHandler.h   |  1 +
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/src/apps/debugger/ThreadHandler.cpp b/src/apps/debugger/ThreadHandler.cpp
index f5559b6162..9a5715565e 100644
--- a/src/apps/debugger/ThreadHandler.cpp
+++ b/src/apps/debugger/ThreadHandler.cpp
@@ -1,6 +1,6 @@
 /*
  * Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
- * Copyright 2010, Rene Gollent, rene@gollent.com.
+ * Copyright 2010-2011, Rene Gollent, rene@gollent.com.
  * Distributed under the terms of the MIT License.
  */
 
@@ -22,6 +22,7 @@
 #include "InstructionInfo.h"
 #include "Jobs.h"
 #include "MessageCodes.h"
+#include "Register.h"
 #include "SourceCode.h"
 #include "SpecificImageDebugInfo.h"
 #include "StackTrace.h"
@@ -52,6 +53,7 @@ ThreadHandler::ThreadHandler(Thread* thread, Worker* worker,
 	fStepStatement(NULL),
 	fBreakpointAddress(0),
 	fPreviousInstructionPointer(0),
+	fPreviousFrameAddress(0),
 	fSingleStepping(false)
 {
 	fDebuggerInterface->AcquireReference();
@@ -294,16 +296,12 @@ ThreadHandler::HandleThreadAction(uint32 action)
 
 	// For "step out" just set a temporary breakpoint on the return address.
 	if (action == MSG_THREAD_STEP_OUT) {
-// TODO: That's OK in principle, but needs additional work with recursive
-// functions. We need to store some information that allows us to determine
-// whether we've actually stepped out of the current frame when we have hit
-// the breakpoint.
 		status_t error = _InstallTemporaryBreakpoint(frame->ReturnAddress());
 		if (error != B_OK) {
 			_StepFallback();
 			return;
 		}
-
+		fPreviousFrameAddress = frame->FrameAddress();
 		fStepMode = STEP_OUT;
 		_RunThread(frame->GetCpuState()->InstructionPointer());
 		return;
@@ -571,8 +569,25 @@ ThreadHandler::_HandleBreakpointHitStep(CpuState* cpuState)
 
 		case STEP_INTO:
 			// Should never happen -- we don't set a breakpoint in this case.
+			return false;
+
 		case STEP_OUT:
-			// That's the return address, so we're done.
+			{
+				// That's the return address, so we're done in theory,
+				// unless we're a recursive function. Check if we've actually
+				// exited the previous stack frame or not.
+				if (cpuState->StackFramePointer() <= fPreviousFrameAddress) {
+					status_t error = _InstallTemporaryBreakpoint(
+						cpuState->InstructionPointer());
+					if (error != B_OK)
+						_StepFallback();
+					else
+						_RunThread(cpuState->InstructionPointer());
+					return true;
+				}
+				fPreviousFrameAddress = 0;
+			}
+
 		default:
 			return false;
 	}
diff --git a/src/apps/debugger/ThreadHandler.h b/src/apps/debugger/ThreadHandler.h
index 57a9c77499..1d4ad339b1 100644
--- a/src/apps/debugger/ThreadHandler.h
+++ b/src/apps/debugger/ThreadHandler.h
@@ -100,6 +100,7 @@ private:
 			Statement*			fStepStatement;
 			target_addr_t		fBreakpointAddress;
 			target_addr_t		fPreviousInstructionPointer;
+			target_addr_t		fPreviousFrameAddress;
 			bool				fSingleStepping;
 
 public: