When the callstack collection mode is enabled for certain profiler markers (such as GC.Alloc), the profiler writes the callstack to the data stream. The callstack refers to the instruction pointer stack.
Instruction pointers can be resolved into function names which you can the use to identify the sample origin in the source code.
GetItemCallstack retrieves the callstack as a list of pointers. Each list entry represents a function call.
Use FrameDataView.ResolveMethodInfo to get method name and location information for the instruction pointer.