Some optimizations for ThreadHandler.

- CreateStackTrace() now takes a parameter indicating whether or not
  to try and retrieve full frame information. This in turn is passed
  on to SpecificImageDebugInfo, where e.g. DwarfImageDebugInfo can
  use it to avoid constructing variables and parameters. This is
  used by ThreadHandler since, when it requests the top frame for
  its stepping  calculations, this additional data/work is completely
  unnecessary.

src/apps/debugger/arch/Architecture.cpp

@@ -94,7 +94,8 @@ Architecture::InitRegisterRules(CfaContext& context) const
 status_t
 Architecture::CreateStackTrace(Team* team,
 	ImageDebugInfoProvider* imageInfoProvider, CpuState* cpuState,
-	StackTrace*& _stackTrace, int32 maxStackDepth, bool useExistingTrace)
+	StackTrace*& _stackTrace, int32 maxStackDepth, bool useExistingTrace,
+	bool getFullFrameInfo)
 {
 	BReference<CpuState> cpuStateReference(cpuState);
 
@@ -161,16 +162,17 @@ Architecture::CreateStackTrace(Team* team,
 		CpuState* previousCpuState = NULL;
 		if (function != NULL) {
 			status_t error = functionDebugInfo->GetSpecificImageDebugInfo()
-				->CreateFrame(image, function, cpuState, frame,
-					previousCpuState);
+				->CreateFrame(image, function, cpuState, getFullFrameInfo,
+					frame, previousCpuState);
 			if (error != B_OK && error != B_UNSUPPORTED)
 				break;
 		}
 
 		// If we have no frame yet, let the architecture create it.
 		if (frame == NULL) {
 			status_t error = CreateStackFrame(image, functionDebugInfo,
-				cpuState, nextFrame == NULL, frame, previousCpuState);
+				cpuState, nextFrame == NULL, frame,
+				previousCpuState);
 			if (error != B_OK)
 				break;
 		}

src/apps/debugger/arch/Architecture.h

@@ -109,7 +109,8 @@ class Architecture : public BReferenceable {
 									CpuState* cpuState,
 									StackTrace*& _stackTrace,
 									int32 maxStackDepth = -1,
-									bool useExistingTrace = false);
+									bool useExistingTrace = false,
+									bool getFullFrameInfo = true);
 										// team is not locked
 
 	virtual	status_t			GetWatchpointDebugCapabilities(

src/apps/debugger/controllers/ThreadHandler.cpp

@@ -253,7 +253,8 @@ ThreadHandler::HandleThreadAction(uint32 action)
 
 	if (stackTrace == NULL && cpuState != NULL) {
 		if (fDebuggerInterface->GetArchitecture()->CreateStackTrace(
-				fThread->GetTeam(), this, cpuState, stackTrace, 1) == B_OK) {
+				fThread->GetTeam(), this, cpuState, stackTrace, 1, false,
+				false) == B_OK) {
 			stackTraceReference.SetTo(stackTrace, true);
 		}
 	}

src/apps/debugger/debug_info/DebuggerImageDebugInfo.cpp

@@ -68,7 +68,8 @@ DebuggerImageDebugInfo::GetAddressSectionType(target_addr_t address)
 status_t
 DebuggerImageDebugInfo::CreateFrame(Image* image,
 	FunctionInstance* functionInstance, CpuState* cpuState,
-	StackFrame*& _previousFrame, CpuState*& _previousCpuState)
+	bool getFullFrameInfo, StackFrame*& _previousFrame,
+	CpuState*& _previousCpuState)
 {
 	return B_UNSUPPORTED;
 }

src/apps/debugger/debug_info/DebuggerImageDebugInfo.h

@@ -35,6 +35,7 @@ class DebuggerImageDebugInfo : public SpecificImageDebugInfo {
 	virtual	status_t			CreateFrame(Image* image,
 									FunctionInstance* functionInstance,
 									CpuState* cpuState,
+									bool getFullFrameInfo,
 									StackFrame*& _previousFrame,
 									CpuState*& _previousCpuState);
 	virtual	status_t			GetStatement(FunctionDebugInfo* function,

src/apps/debugger/debug_info/DwarfImageDebugInfo.cpp

@@ -516,7 +516,7 @@ DwarfImageDebugInfo::GetAddressSectionType(target_addr_t address)
 status_t
 DwarfImageDebugInfo::CreateFrame(Image* image,
 	FunctionInstance* functionInstance, CpuState* cpuState,
-	StackFrame*& _frame, CpuState*& _previousCpuState)
+	bool getFullFrameInfo, StackFrame*& _frame, CpuState*& _previousCpuState)
 {
 	DwarfFunctionDebugInfo* function = dynamic_cast<DwarfFunctionDebugInfo*>(
 		functionInstance->GetFunctionDebugInfo());
@@ -635,7 +635,7 @@ DwarfImageDebugInfo::CreateFrame(Image* image,
 	// The subprogram entry may not be available since this may be a case
 	// where .eh_frame was used to unwind the stack without other DWARF
 	// info being available.
-	if (subprogramEntry != NULL) {
+	if (subprogramEntry != NULL && getFullFrameInfo) {
 		// create function parameter objects
 		for (DebugInfoEntryList::ConstIterator it
 			= subprogramEntry->Parameters().GetIterator();

src/apps/debugger/debug_info/DwarfImageDebugInfo.h

@@ -61,6 +61,7 @@ class DwarfImageDebugInfo : public SpecificImageDebugInfo {
 	virtual	status_t			CreateFrame(Image* image,
 									FunctionInstance* functionInstance,
 									CpuState* cpuState,
+									bool getFullFrameInfo,
 									StackFrame*& _frame,
 									CpuState*& _previousCpuState);
 	virtual	status_t			GetStatement(FunctionDebugInfo* function,

src/apps/debugger/debug_info/SpecificImageDebugInfo.h

@@ -55,11 +55,15 @@ class SpecificImageDebugInfo : public BReferenceable {
 	virtual	status_t			CreateFrame(Image* image,
 									FunctionInstance* functionInstance,
 									CpuState* cpuState,
+									bool getFullFrameInfo,
 									StackFrame*& _Frame,
 									CpuState*& _previousCpuState) = 0;
 										// returns reference to previous frame
 										// and CPU state; returned CPU state
 										// can be NULL; can return B_UNSUPPORTED
+										// getFullFrameInfo: try to retrieve
+										// variables/parameters if true
+										// (and supported)
 	virtual	status_t			GetStatement(FunctionDebugInfo* function,
 									target_addr_t address,
 									Statement*& _statement) = 0;