Get types used inside a C# method body
Is there a way to get all types used inside C# method?
For example,
public int foo(string str)
{
Bar bar = new Bar();
string x = "test";
TEST t = bar.GetTEST();
}
would return: Bar, string and TEST.
All I can get now is the method body text using EnvDTE.CodeFunction. Maybe there is a better way to achieve it than trying to parse this code.
I'm going to take this opportunity to post up a proof of concept I did because somebody told me it couldn't be done - with a bit of tweaking here and there, it'd be relatively trivial to extend this to extract out all referenced Types in a method - apologies for the size of it and the lack of a preface, but it's somewhat commented:
void Main()
{
Func<int,int> addOne = i => i + 1;
Console.WriteLine(DumpMethod(addOne));
Func<int,string> stuff = i =>
{
var m = 10312;
var j = i + m;
var k = j * j + i;
var foo = "Bar";
var asStr = k.ToString();
return foo + asStr;
};
Console.WriteLine(DumpMethod(stuff));
Console.WriteLine(DumpMethod((Func<string>)Foo.GetFooName));
Console.WriteLine(DumpMethod((Action)Console.Beep));
}
public class Foo
{
public const string FooName = "Foo";
public static string GetFooName() { return typeof(Foo).Name + ":" + FooName; }
}
public static string DumpMethod(Delegate method)
{
// For aggregating our response
StringBuilder sb = new StringBuilder();
// First we need to extract out the raw IL
var mb = method.Method.GetMethodBody();
var il = mb.GetILAsByteArray();
// We'll also need a full set of the IL opcodes so we
// can remap them over our method body
var opCodes = typeof(System.Reflection.Emit.OpCodes)
.GetFields()
.Select(fi => (System.Reflection.Emit.OpCode)fi.GetValue(null));
//opCodes.Dump();
// For each byte in our method body, try to match it to an opcode
var mappedIL = il.Select(op =>
opCodes.FirstOrDefault(opCode => opCode.Value == op));
// OpCode/Operand parsing:
// Some opcodes have no operands, some use ints, etc.
// let's try to cover all cases
var ilWalker = mappedIL.GetEnumerator();
while(ilWalker.MoveNext())
{
var mappedOp = ilWalker.Current;
if(mappedOp.OperandType != OperandType.InlineNone)
{
// For operand inference:
// MOST operands are 32 bit,
// so we'll start there
var byteCount = 4;
long operand = 0;
string token = string.Empty;
// For metadata token resolution
var module = method.Method.Module;
Func<int, string> tokenResolver = tkn => string.Empty;
switch(mappedOp.OperandType)
{
// These are all 32bit metadata tokens
case OperandType.InlineMethod:
tokenResolver = tkn =>
{
var resMethod = module.SafeResolveMethod((int)tkn);
return string.Format("({0}())", resMethod == null ? "unknown" : resMethod.Name);
};
break;
case OperandType.InlineField:
tokenResolver = tkn =>
{
var field = module.SafeResolveField((int)tkn);
return string.Format("({0})", field == null ? "unknown" : field.Name);
};
break;
case OperandType.InlineSig:
tokenResolver = tkn =>
{
var sigBytes = module.SafeResolveSignature((int)tkn);
var catSig = string
.Join(",", sigBytes);
return string.Format("(SIG:{0})", catSig == null ? "unknown" : catSig);
};
break;
case OperandType.InlineString:
tokenResolver = tkn =>
{
var str = module.SafeResolveString((int)tkn);
return string.Format("('{0}')", str == null ? "unknown" : str);
};
break;
case OperandType.InlineType:
tokenResolver = tkn =>
{
var type = module.SafeResolveType((int)tkn);
return string.Format("(typeof({0}))", type == null ? "unknown" : type.Name);
};
break;
// These are plain old 32bit operands
case OperandType.InlineI:
case OperandType.InlineBrTarget:
case OperandType.InlineSwitch:
case OperandType.ShortInlineR:
break;
// These are 64bit operands
case OperandType.InlineI8:
case OperandType.InlineR:
byteCount = 8;
break;
// These are all 8bit values
case OperandType.ShortInlineBrTarget:
case OperandType.ShortInlineI:
case OperandType.ShortInlineVar:
byteCount = 1;
break;
}
// Based on byte count, pull out the full operand
for(int i=0; i < byteCount; i++)
{
ilWalker.MoveNext();
operand |= ((long)ilWalker.Current.Value) << (8 * i);
}
var resolved = tokenResolver((int)operand);
resolved = string.IsNullOrEmpty(resolved) ? operand.ToString() : resolved;
sb.AppendFormat("{0} {1}",
mappedOp.Name,
resolved)
.AppendLine();
}
else
{
sb.AppendLine(mappedOp.Name);
}
}
return sb.ToString();
}
public static class Ext
{
public static FieldInfo SafeResolveField(this Module m, int token)
{
FieldInfo fi;
m.TryResolveField(token, out fi);
return fi;
}
public static bool TryResolveField(this Module m, int token, out FieldInfo fi)
{
var ok = false;
try { fi = m.ResolveField(token); ok = true; }
catch { fi = null; }
return ok;
}
public static MethodBase SafeResolveMethod(this Module m, int token)
{
MethodBase fi;
m.TryResolveMethod(token, out fi);
return fi;
}
public static bool TryResolveMethod(this Module m, int token, out MethodBase fi)
{
var ok = false;
try { fi = m.ResolveMethod(token); ok = true; }
catch { fi = null; }
return ok;
}
public static string SafeResolveString(this Module m, int token)
{
string fi;
m.TryResolveString(token, out fi);
return fi;
}
public static bool TryResolveString(this Module m, int token, out string fi)
{
var ok = false;
try { fi = m.ResolveString(token); ok = true; }
catch { fi = null; }
return ok;
}
public static byte[] SafeResolveSignature(this Module m, int token)
{
byte[] fi;
m.TryResolveSignature(token, out fi);
return fi;
}
public static bool TryResolveSignature(this Module m, int token, out byte[] fi)
{
var ok = false;
try { fi = m.ResolveSignature(token); ok = true; }
catch { fi = null; }
return ok;
}
public static Type SafeResolveType(this Module m, int token)
{
Type fi;
m.TryResolveType(token, out fi);
return fi;
}
public static bool TryResolveType(this Module m, int token, out Type fi)
{
var ok = false;
try { fi = m.ResolveType(token); ok = true; }
catch { fi = null; }
return ok;
}
}
If you can access the IL for this method, you might be able to do something suitable. Perhaps look at the open source project ILSpy and see whether you can leverage any of their work.