fixed callstack/callers output

coprocessor/developer/callstack/callstack.go

@@ -32,9 +32,6 @@ type CallStack struct {
 
 	// list of callers for all executed functions
 	Callers map[string]([]*dwarf.SourceLine)
-
-	// prevLine is helpful when creating the Callers list
-	PrevLine *dwarf.SourceLine
 }
 
 // NewCallStack is the preferred method of initialisation for the CallStack type
@@ -60,24 +57,19 @@ func (cs CallStack) WriteCallers(function string, w io.Writer) error {
 
 	const maxDepth = 15
 
-	var f func(callLines []*dwarf.SourceLine, depth int) error
-	f = func(callLines []*dwarf.SourceLine, depth int) error {
+	var f func(lines []*dwarf.SourceLine, depth int) error
+	f = func(lines []*dwarf.SourceLine, depth int) error {
 		indent := strings.Builder{}
 		for i := 0; i < depth; i++ {
-			indent.WriteString("  ")
+			indent.WriteString(" ")
 		}
 
 		if depth > maxDepth {
 			return errors.New(fmt.Sprintf("%stoo deep", indent.String()))
 		}
 
-		for _, ln := range callLines {
-			if ln.IsStub() {
-				return nil
-			}
-
-			s := fmt.Sprintf("%s (%s:%d)", ln.Function.Name, ln.File.ShortFilename, ln.LineNumber)
-			w.Write([]byte(fmt.Sprintf("%s%s", indent.String(), s)))
+		for _, ln := range lines {
+			w.Write([]byte(fmt.Sprintf("%s%s", indent.String(), ln.Function.Name)))
 			if l, ok := cs.Callers[ln.Function.Name]; ok {
 				err := f(l, depth+1)
 				if err != nil {

coprocessor/developer/developer.go

@@ -86,6 +86,9 @@ type Developer struct {
 
 	// keeps track of the previous breakpoint check. see checkBreakPointByAddr()
 	prevBreakpointCheck *dwarf.SourceLine
+
+	// keeps track of the previous line in profiling scan. see processProfiling()
+	prevProfileLine *dwarf.SourceLine
 }
 
 // NewDeveloper is the preferred method of initialisation for the Developer type.

coprocessor/developer/dwarf/types.go

@@ -159,7 +159,7 @@ type SourceLine struct {
 
 func (ln *SourceLine) String() string {
 	if ln.IsStub() {
-		return ln.PlainContent
+		return ""
 	}
 	s := strings.Builder{}
 	s.WriteString(fmt.Sprintf("%s:%d", ln.File.ShortFilename, ln.LineNumber))

coprocessor/developer/profiling.go

@@ -70,29 +70,29 @@ func (dev *Developer) ProcessProfiling() {
 		defer dev.callstackLock.Unlock()
 
 		for _, p := range dev.profiler.Entries {
-			l := len(dev.callstack.Stack)
-			lastLn := dev.callstack.Stack[l-1]
-
 			// line of executed instruction. every instruction should have an
 			// associated line/function. if it does not then we assume it is in
-			// the entry function
+			// the driver function
 			ln, ok := dev.source.LinesByAddress[uint64(p.Addr)]
 			if !ok {
 				ln = dev.source.DriverSourceLine
 				dev.source.LinesByAddress[uint64(p.Addr)] = ln
 			}
 
-			// if function has changed
-			if ln != lastLn {
-				popped := false
+			// callstack
+			l := len(dev.callstack.Stack)
+			prevCallStack := dev.callstack.Stack[l-1]
 
-				// try to pop
+			// change callstack if function has changed
+			if ln.Function != prevCallStack.Function {
+				var popped bool
+
+				// try to pop entry from callstack
 				var i int
-				for i = 1; i <= l; i++ {
+				for i = 1; i <= l && !popped; i++ {
 					if ln.Function == dev.callstack.Stack[l-i].Function {
 						chop := dev.callstack.Stack[l-i+1:]
 						dev.callstack.Stack = dev.callstack.Stack[:l-i+1]
-						popped = true
 
 						// flag functions which look like they are part of an
 						// optimised call stack
@@ -102,7 +102,8 @@ func (dev *Developer) ProcessProfiling() {
 							}
 						}
 
-						break // for loop
+						// setting popped will cause the loop to end early
+						popped = true
 					}
 				}
 
@@ -110,10 +111,6 @@ func (dev *Developer) ProcessProfiling() {
 				if !popped {
 					dev.callstack.Stack = append(dev.callstack.Stack, ln)
 
-					// there is always at least one entry in the functions callstack so we can
-					// confidently subtract two from the length after the append above
-					// prev := dev.callstack.functions[len(dev.callstack.functions)-2]
-
 					// create/update callers list for function
 					var n int
 					l, ok := dev.callstack.Callers[ln.Function.Name]
@@ -122,15 +119,15 @@ func (dev *Developer) ProcessProfiling() {
 							return ln == l[i]
 						})
 					}
-					if !ok || (n > len(l) && l[n] != dev.callstack.PrevLine) {
-						l = append(l, dev.callstack.PrevLine)
+
+					if !ok || (n > len(l) && l[n] != dev.prevProfileLine) {
+						l = append(l, dev.prevProfileLine)
 						sort.Slice(l, func(i, j int) bool {
 							return l[i].Function.Name < l[j].Function.Name
 						})
 						dev.callstack.Callers[ln.Function.Name] = l
 					}
 				}
-
 			}
 
 			// accumulate counts for line (and the line's function)
@@ -142,7 +139,7 @@ func (dev *Developer) ProcessProfiling() {
 			}
 
 			// record line for future comparison
-			dev.callstack.PrevLine = ln
+			dev.prevProfileLine = ln
 		}
 
 		// empty slice