private static Dictionary <string, IntPtr> ParseSymbols(string pdbPath, IntPtr moduleAddress)
{
var symbols = new Dictionary <string, IntPtr>();
// Initialise a symbol handler for the local process
using var localProcess = Process.GetCurrentProcess();
if (!Dbghelp.SymInitialize(localProcess.SafeHandle, IntPtr.Zero, false))
{
throw new Win32Exception($"Failed to call SymInitialize with error code {Marshal.GetLastWin32Error()}");
}
// Load the symbol table for the PDB
var pdbPathBuffer = Encoding.Default.GetBytes(pdbPath);
var symbolTableBaseAddress = Dbghelp.SymLoadModuleEx(localProcess.SafeHandle, IntPtr.Zero, ref pdbPathBuffer[0], IntPtr.Zero, moduleAddress, (int)new FileInfo(pdbPath).Length, IntPtr.Zero, 0);
if (symbolTableBaseAddress == IntPtr.Zero)
{
throw new Win32Exception($"Failed to call SymLoadModuleEx with error code {Marshal.GetLastWin32Error()}");
}
// Initialise the callback used during the SymEnumSymbols call
bool Callback(ref SymbolInfo symbolInfo, int symbolSize, IntPtr userContext)
{
var symbolNameBuffer = new byte[symbolInfo.NameLen];
Unsafe.CopyBlockUnaligned(ref symbolNameBuffer[0], ref symbolInfo.Name, (uint)symbolNameBuffer.Length);
symbols.TryAdd(Encoding.Default.GetString(symbolNameBuffer), (IntPtr)symbolInfo.Address);
return(true);
}
var callbackDelegate = new Prototypes.EnumerateSymbolsCallback(Callback);
// Enumerate the PDB symbols
if (!Dbghelp.SymEnumSymbols(localProcess.SafeHandle, symbolTableBaseAddress, IntPtr.Zero, callbackDelegate, IntPtr.Zero))
{
throw new Win32Exception($"Failed to call SymEnumSymbols with error code {Marshal.GetLastWin32Error()}");
}
if (!Dbghelp.SymUnloadModule(localProcess.SafeHandle, symbolTableBaseAddress))
{
throw new Win32Exception($"Failed to call SymUnloadModule with error code {Marshal.GetLastWin32Error()}");
}
return(symbols);
}
internal int GetSymbolAddress(string symbolName)
{
// Initialise a symbol handler
Dbghelp.SymSetOptions(SymbolOptions.UndecorateName);
using var currentProcessHandle = Process.GetCurrentProcess().SafeHandle;
if (!Dbghelp.SymInitialize(currentProcessHandle, null, false))
{
throw new Win32Exception();
}
try
{
const int pseudoDllAddress = 0x1000;
// Load the symbol table for the PDB into the symbol handler
var pdbSize = new FileInfo(_pdbFilePath).Length;
var symbolTableAddress = Dbghelp.SymLoadModule(currentProcessHandle, IntPtr.Zero, _pdbFilePath, null, pseudoDllAddress, (int)pdbSize);
if (symbolTableAddress == 0)
{
throw new Win32Exception();
}
// Initialise an array to receive the symbol information
var symbolInformationSize = (Unsafe.SizeOf <SymbolInfo>() + sizeof(char) * Constants.MaxSymbolNameLength + sizeof(long) - 1) / sizeof(long);
Span <byte> symbolInformationBytes = stackalloc byte[symbolInformationSize];
MemoryMarshal.Write(symbolInformationBytes, ref Unsafe.AsRef(new SymbolInfo(Constants.MaxSymbolNameLength)));
try
{
// Retrieve the symbol information
if (!Dbghelp.SymFromName(currentProcessHandle, symbolName, out symbolInformationBytes[0]))
{
throw new Win32Exception();
}
}
catch
{
Dbghelp.SymUnloadModule(currentProcessHandle, pseudoDllAddress);
throw;
}
if (!Dbghelp.SymUnloadModule(currentProcessHandle, pseudoDllAddress))
{
throw new Win32Exception();
}
// Calculate the address of the symbol
var symbolInformation = MemoryMarshal.Read <SymbolInfo>(symbolInformationBytes);
return((int)symbolInformation.Address - pseudoDllAddress);
}
finally
{
Dbghelp.SymCleanup(currentProcessHandle);
}
}
