Closed
Description
Background and motivation
VS4Mac needs a way to symbolize managed IPs when rethrowing a native NSException from Objective C++. They do the symbolizing in the telemetry upload on the unhandled NSException crash. They don't currently build a StackTrace/StackFrames when the managed NSException wrapper is thrown so all they need currently is a way to convert a IP address of a managed method into a full method name string.
This is a short term API needed for the next 6.0 service release discoverable only through reflection.
API Proposal
namespace System.Diagnostics
{
public class StackFrame
{
/// <summary>
/// Returns the method info instance for the managed code IP address.
/// </summary>
/// <param name="ip">code address</param>
/// <returns>MethodBase instance or null if IP not found</returns>
internal static MethodBase? GetMethodFromNativeIP(IntPtr ip);
}
}API Usage
Type stackFrameType = typeof(System.Diagnostics.StackFrame);
MethodInfo? getMethodFromNativeIP = stackFrameType.GetMethod("GetMethodFromNativeIP", BindingFlags.NonPublic | BindingFlags.Static);
if (getMethodFromNativeIP is null)
{
Console.WriteLine("GetMethodFromNativeIP not found");
return;
}
long ip = 0;
MethodBase? testFunction = getMethodFromNativeIP.Invoke(null, new object[] { new IntPtr(ip) }) as MethodBase;
if (testFunction is null)
{
Console.WriteLine("Test function not found");
return;
}Alternative Designs
For .NET 7.0, we could replace this temporary API with this public one:
public class StackFrame
{
public static StackFrame? CreateFromNativeIP(IntPtr nativeIP, bool needFileInfo = false);
}
Risks
The .NET 6.0 API has the following limitations that will need to be addressed:
- There is a race condition for dynamic and collectable methods between when the MethodDesc is found and where it is wrapped in the MethodBase.
- MethodBase isn't a good design choice for working with NativeAOT.