Debugging LCG

re: Debugging LCG

barrkel — Fri, 27 May 2005 11:25:21 GMT

The ILGenerator.Emit() call has lots of overloads for the second parameter, including both int32 and int64. The LDC_I8 opcode tries to load an int64, but the C# type of 0 is int32, so the wrong overload is called, and not enough data gets written. If you change the line:

ilgen.Emit(OpCodes.Ldc_I8, 0);

to:

ilgen.Emit(OpCodes.Ldc_I8, (long) 0);

the program will work as expected.

Yiru on Debugging LCG

.Net Security Blog — Sat, 28 May 2005 00:07:09 GMT

Yiru's got a great piece up on using SOS to debug code that was emitted using Whidbey's new Lightweight...

re: Debugging LCG

yirutang — Sat, 28 May 2005 04:29:35 GMT

You are right. ;-)

re: Debugging LCG

Anonymous — Sun, 29 May 2005 02:06:05 GMT

This is excellent information on LCG. Thanks, and keep up the great work!

re: Debugging LCG

yunjin — Sat, 18 Jun 2005 01:06:00 GMT

Nice post! It's exciting to see use of our new SOS command like DumpIL and DumpArray.
One comment: to make DumpMD work with decimal value, you could simply prepend "0n" to the number like "0n1541425360". Or, you could even change the debugger engine's default number radix by the command "n 10" ("n 16" will set it back).

re: Debugging LCG

yirutang — Thu, 15 Sep 2005 00:53:42 GMT

I would like to save something just for my own record. Here is how our JIT dev would approach to see the LCG x86 code:

From Shri:

Here’s what I would do. I have not tried this out, so some steps might need to be twead.

Write a program with method foo() that throws and catches a dummy exception (for step 3), and then creates and invokes an LCG method
Compile it and run under windbg
“sxe clr; g” in windbg to catch the dummy exception with foo() on the stack
“bp mscorjit!CILJit::compileMethod; g” to get to the JITing of the dynamic method.
“.loadby sos mscorwks” to load strike
“!dumpmd poi(poi(@esp+c))” to display the MethodDesc that gets passed to CILJit::compileMethod on the stack.
“!bpmd poi(poi(@esp+c))” to put a breakpoint in the dynamic method
“g” to get to the start of the dynamic method
“!u @eip” to display the x86 code

re: Debugging LCG

thanks — Tue, 21 Feb 2006 20:31:05 GMT

Your site is realy very interesting.

DebuggerVisualizer for DynamicMethod (Show me the IL)

Haibo Luo's weblog — Sun, 08 Oct 2006 21:59:21 GMT

Have you ever tried DynamicMethod, one of the coolest features in the .NET 2.0? Hope you have; otherwise,

LCG + Debuggability, and your feedback

Mike Stall's .NET Debugging Blog — Tue, 14 Nov 2006 23:58:17 GMT

I mentioned earlier that you can debug Reflection.Emit code . Unfortunately, Ref.Emit code can't be unloaded