private string GetLocalVariableName(ulong instructionPointer, uint localIndex)
{
ClrMethod method = _context.Runtime.GetMethodByAddress(instructionPointer);
ClrModule module = method.Type.Module;
string pdbLocation = module.TryDownloadPdb(null);
IntPtr iunkMetadataImport = Marshal.GetIUnknownForObject(module.MetadataImport);
ISymbolReader reader = null;
ISymbolMethod symMethod = null;
try
{
using (var binder = new SymBinder())
{
reader = binder.GetReader(
iunkMetadataImport, module.FileName, Path.GetDirectoryName(pdbLocation));
symMethod = reader.GetMethod(new SymbolToken((int)method.MetadataToken));
return(GetLocalVariableName(symMethod.RootScope, localIndex));
}
}
catch (COMException comEx)
{
// E_FAIL occasionally occurs in ISymbolReader.GetMethod. Nothing we can do about it.
if ((uint)comEx.HResult == 0x80004005)
{
return("");
}
// 0x806D0005 occurs when the PDB cannot be found or doesn't contain the necessary
// information to create a symbol reader. It's OK to ignore.
if ((uint)comEx.HResult == 0x806D0005)
{
return("");
}
throw;
}
finally
{
// These interfaces aren't IDisposable, but the underlying objects are. And it is
// important to dispose of them properly, because if their finalizer runs on exit,
// it crashes with an access violation.
if (reader != null)
{
((IDisposable)reader).Dispose();
}
if (symMethod != null)
{
((IDisposable)symMethod).Dispose();
}
Marshal.Release(iunkMetadataImport);
}
}