mono/web/jit-debug-sample2

* A debugging session using a symbol file which has been created by MCS.

	Let's assume we have the following C# application which we want to debug:

	<pre>
	using System;

	public class Foo
	{
		public struct MyStruct {
			int a;
			long b;
			double c;
		}

		public static void Main ()
		{
			Int32 value = 5;
			long test = 512;

			MyStruct my_struct;
			my_struct.a = 5;
			my_struct.b = test;
			my_struct.c = 23323.5235;
		}
	}
	</pre>

	First of all, we need to compile it with MCS, assemble the generated .s file and
	create the .il files for all referenced assemblies which were not compiled with MCS:

	<pre>
	$ mcs -g ./Foo.cs
	$ as -o Foo-debug.o Foo-debug.s
	$ monodis /home/export/martin/MONO-LINUX/lib/corlib.dll > corlib.il
	</pre>

	Now we can start the JIT in the debugger:

	<pre>
	$ gdb ~/monocvs/mono/mono/jit/mono
	(gdb) r --dwarf-plus --debug Foo:Main ./Foo.exe
	Starting program: /home/martin/monocvs/mono/mono/jit/mono --dwarf-plus --debug Foo:Main ./Foo.exe
	Program received signal SIGTRAP, Trace/breakpoint trap.
	0x081e8681 in ?? ()
	(gdb) call mono_debug_make_symbols ()
	(gdb) add-symbol-file Foo-debug.o
	(gdb) add-symbol-file /tmp/corlib.o
`	(gdb) frame
	#0  Main () at ./Foo.cs:11
	11              public static void Main ()
	(gdb) n
	Main () at ./Foo.cs:13
	13                      Int32 value = 5;
	(gdb)
	14                      long test = 512;
	(gdb)
	17                      my_struct.a = 5;
	(gdb)
	18                      my_struct.b = test;
	(gdb)
	19                      my_struct.c = 23323.5235;
	(gdb)
	20              }
	(gdb) info locals
	value = 5
	test = 512
	my_struct = { a = 5, b = 512, c = 23323.5235 }
	</pre>