async Task <MethodInfo> LoadSymbolsOnDemand(AssemblyInfo asm, uint method_token, SessionId sessionId, CancellationToken token)
{
var context = GetContext(sessionId);
if (asm.TriedToLoadSymbolsOnDemand)
{
return(null);
}
asm.TriedToLoadSymbolsOnDemand = true;
ImageDebugHeader header = asm.Image.GetDebugHeader();
for (var i = 0; i < header.Entries.Length; i++)
{
var entry = header.Entries[i];
if (entry.Directory.Type != ImageDebugType.CodeView)
{
continue;
}
var data = entry.Data;
if (data.Length < 24)
{
return(null);
}
var pdbSignature = (data[0]
| (data[1] << 8)
| (data[2] << 16)
| (data[3] << 24));
if (pdbSignature != 0x53445352) // "SDSR" mono/metadata/debug-mono-ppdb.c#L101
{
return(null);
}
var buffer = new byte[16];
Buffer.BlockCopy(data, 4, buffer, 0, 16);
var pdbAge = (data[20]
| (data[21] << 8)
| (data[22] << 16)
| (data[23] << 24));
var pdbGuid = new Guid(buffer);
var buffer2 = new byte[(data.Length - 24) - 1];
Buffer.BlockCopy(data, 24, buffer2, 0, (data.Length - 24) - 1);
var pdbName = System.Text.Encoding.UTF8.GetString(buffer2, 0, buffer2.Length);
pdbName = Path.GetFileName(pdbName);
foreach (var urlSymbolServer in urlSymbolServerList)
{
var downloadURL = $"{urlSymbolServer}/{pdbName}/{pdbGuid.ToString("N").ToUpper() + pdbAge}/{pdbName}";
try
{
using HttpResponseMessage response = await client.GetAsync(downloadURL);
using Stream streamToReadFrom = await response.Content.ReadAsStreamAsync();
var portablePdbReaderProvider = new PdbReaderProvider();
var symbolReader = portablePdbReaderProvider.GetSymbolReader(asm.Image, streamToReadFrom);
asm.ClearDebugInfo(); //workaround while cecil PR #686 is not merged
asm.Image.ReadSymbols(symbolReader);
asm.Populate();
foreach (var source in asm.Sources)
{
var scriptSource = JObject.FromObject(source.ToScriptSource(context.Id, context.AuxData));
SendEvent(sessionId, "Debugger.scriptParsed", scriptSource, token);
}
return(asm.GetMethodByToken(method_token));
}
catch (Exception e)
{
Log("info", $"Unable to load symbols on demand exception: {e.ToString()} url:{downloadURL} assembly: {asm.Name}");
}
}
break;
}
Log("info", "Unable to load symbols on demand assembly: {asm.Name}");
return(null);
}