|
public static IterateInstructions ( Mono.Cecil method ) : IEnumerable |
||
| method | Mono.Cecil | |
| return | IEnumerable |
|
/// <summary>
/// Generate "position independent" representation of IL.
///
/// We need to do this extra work because even if we skip
/// instrumentation prologue of functions when iterating
/// instructions, typical "toString()" representation of
/// Cecil.Cil.Instructions contains absolute instruction
/// positions.
/// </summary>
string ConcatBody(Cecil.MethodDefinition method)
{
const string skipAddr = "IL_0000: ";
var sb = new System.Text.StringBuilder();
foreach (var ins in Instrument.IterateInstructions(method))
{
if (ins.Operand is Cecil.Cil.Instruction)
{
// instructions that refer to other instructions, like
// branches.
var insOperand = (Cecil.Cil.Instruction)(ins.Operand);
var offset = insOperand.Offset - ins.Offset;
sb.AppendLine(String.Format("{0} {1}", ins.OpCode, offset));
}
else
{
sb.AppendLine(ins.ToString().Substring(skipAddr.Length));
}
}
return(sb.ToString());
}
public DynamicMethod RecompileMethod(Cecil.MethodDefinition methodDef)
{
Debug.Trace("Recompiling method: {0}", methodDef.FullName);
var declaringType = FindType(methodDef.DeclaringType);
var returnType = FindType(methodDef.ReturnType);
Type[] paramTypes = methodDef.Parameters.Select((paramDef) => {
return(FindType(paramDef.ParameterType));
}).ToArray();
if (!methodDef.IsStatic)
{
paramTypes = new Type[] { declaringType }.Concat(paramTypes).ToArray();
}
var dynMethod = new DynamicMethod(methodDef.Name, returnType, paramTypes, true);
ILGenerator il = dynMethod.GetILGenerator();
dynMethod.InitLocals = methodDef.Body.InitLocals;
foreach (var variable in methodDef.Body.Variables)
{
var localType = FindType(variable.VariableType);
Debug.Trace("Declaring local (cecil type: {0}) of type (runtime type: {1})", variable.VariableType, localType);
il.DeclareLocal(localType);
}
var labels = new Dictionary <Cecil.Cil.Instruction, Label>();
foreach (var inst in methodDef.Body.Instructions)
{
if (inst.Operand != null && inst.Operand.GetType() == typeof(Cecil.Cil.Instruction))
{
var opinst = (Cecil.Cil.Instruction)(inst.Operand);
labels[opinst] = il.DefineLabel();
}
}
foreach (var inst in Instrument.IterateInstructions(methodDef))
{
Debug.Trace("Emitting: {0}", inst);
Label label;
if (labels.TryGetValue(inst, out label))
{
il.MarkLabel(label);
}
var ilop = FindOpcode(inst.OpCode);
if (inst.Operand != null)
{
var operand = inst.Operand;
var operandType = operand.GetType();
// Dynamic dispatch implementation:
// We have to run different processing code depending on the type of instruction
// operand. Visitor pattern cannot be implemented here, because we don't actually
// own the classes that are the operands (and some of them are primitive or system
// types).
// Therefore, dynamic dispatcher is used. Method for each operand type is implemented
// in this class, and reflection is used to find correct method to call.
// In newer .net versions we would be able to do EmitInstruction(il, ilop, (dynamic)operand),
// but the .net version we are targeting (because of Unity compatibility) does not
// have `dynamic`.
if (operandType == typeof(Cecil.Cil.Instruction))
{
//branch location
var operandInst = (Cecil.Cil.Instruction)operand;
il.Emit(ilop, labels[operandInst]);
}
else if (primitiveOperandTypes.Contains(operandType))
{
//if operand is primitive, call il.Emit directly
Reflection.MethodInfo method;
if (!EmitPrimitiveCache.TryGetValue(operandType, out method))
{
method = typeof(ILGenerator).GetMethod("Emit", new Type[] { typeof(OpCode), operandType });
EmitPrimitiveCache[operandType] = method;
}
if (method == null)
{
throw new Exception(String.Format("Emit method for primitive type {0} not found.", operandType.Name));
}
method.Invoke(il, new object[] { ilop, operand });
}
else
{
//or else, call our EmitInstruction
Reflection.MethodInfo method;
if (!EmitInstructionCache.TryGetValue(operandType, out method))
{
method = GetType().GetMethod("EmitInstruction",
bindingAttr: bflags_all_instance,
binder: null,
modifiers: null,
types: new Type[] { typeof(ILGenerator), typeof(OpCode), operandType });
EmitInstructionCache[operandType] = method;
}
if (method == null)
{
throw new Exception(String.Format("Don't know what to do with operand {0}", operandType.Name));
}
method.Invoke(this, new object[] { il, ilop, operand });
}
}
else
{
il.Emit(ilop);
}
}
return(dynMethod);
}
