public static IsWeakInstanceOfConditional Create(BasicBlockScanner scanner, ref BasicBlock bb, ref int index, TypeDefinition type)
{
if (bb.Instructions.Count == 1)
{
throw new OptimizerAssertionException();
}
if (index + 1 >= scanner.Body.Instructions.Count)
{
throw new OptimizerAssertionException();
}
/*
* `bool MonoLinkerSupport.IsWeakInstance<T> (object instance)`
*
* If the function argument is a simple load (like for instance `Ldarg_0`),
* then we can simply remove that load. Otherwise, we need to insert a
* `Pop` to discard the value on the stack.
*
* In either case, we always start a new basic block for the conditional.
* Its first instruction will either be the simple load or the call itself.
*/
var argument = scanner.Body.Instructions [index - 1];
scanner.LogDebug(1, $"WEAK INSTANCE OF: {bb} {index} {type} - {argument}");
bool hasLoad;
TypeDefinition instanceType;
if (CecilHelper.IsSimpleLoad(argument))
{
if (bb.Instructions.Count > 2)
{
scanner.BlockList.SplitBlockAt(ref bb, bb.Instructions.Count - 2);
}
instanceType = CecilHelper.GetWeakInstanceArgument(bb.Instructions [1]);
hasLoad = true;
}
else
{
scanner.BlockList.SplitBlockAt(ref bb, bb.Instructions.Count - 1);
instanceType = CecilHelper.GetWeakInstanceArgument(bb.Instructions [0]);
hasLoad = false;
}
var instance = new IsWeakInstanceOfConditional(scanner, instanceType, hasLoad);
bb.LinkerConditional = instance;
/*
* Once we get here, the current block only contains the (optional) simple load
* and the conditional call itself.
*/
LookAheadAfterConditional(scanner.BlockList, ref bb, ref index);
return(instance);
}
public static AsWeakInstanceOfConditional Create(BasicBlockScanner scanner, ref BasicBlock bb, ref int index, TypeDefinition type)
{
if (bb.Instructions.Count < 2)
{
throw new OptimizerAssertionException();
}
if (index + 1 >= scanner.Body.Instructions.Count)
{
throw new OptimizerAssertionException();
}
/*
* `bool MonoLinkerSupport.AsWeakInstance<T> (object obj, out T instance)`
*/
var load = scanner.Body.Instructions [index - 2];
var output = scanner.Body.Instructions [index - 1];
scanner.LogDebug(1, $"WEAK INSTANCE OF: {bb} {index} {type} - {load} {output}");
if (!CecilHelper.IsSimpleLoad(load))
{
throw new OptimizerAssertionException();
}
if (output.OpCode.Code != Code.Ldloca && output.OpCode.Code != Code.Ldloca_S)
{
throw new OptimizerAssertionException();
}
if (bb.Instructions.Count > 3)
{
scanner.BlockList.SplitBlockAt(ref bb, bb.Instructions.Count - 2);
}
var instanceType = CecilHelper.GetWeakInstanceArgument(bb.Instructions [2]);
var variable = ((VariableReference)output.Operand).Resolve() ?? throw new OptimizerAssertionException();
var instance = new AsWeakInstanceOfConditional(scanner, instanceType, variable);
bb.LinkerConditional = instance;
/*
* Once we get here, the current block only contains the (optional) simple load
* and the conditional call itself.
*/
LookAheadAfterConditional(scanner.BlockList, ref bb, ref index);
return(instance);
}
public static bool Scan(BasicBlockScanner scanner, ref BasicBlock bb, ref int index, Instruction instruction)
{
var reference = (MethodReference)instruction.Operand;
if (!scanner.Context.TryFastResolve(reference, out var target))
{
return(false);
}
if (target == null)
{
if (reference.DeclaringType.Name.Contains("..."))
{
// FIXME: we don't support Ranges yet.
return(false);
}
scanner.Context.LogMessage(MessageImportance.High, $"Cannot resolve call target: {CecilHelper.Format (instruction)}");
if (scanner.Context.Options.IgnoreResolutionErrors)
{
return(false);
}
throw new ResolutionException(reference);
}
scanner.LogDebug(2, $" CALL: {target}");
if (instruction.Operand is GenericInstanceMethod genericInstance)
{
if (scanner.Context.IsWeakInstanceOfMethod(target))
{
var conditionalType = genericInstance.GenericArguments [0].Resolve();
if (conditionalType == null)
{
throw new ResolutionException(genericInstance.GenericArguments [0]);
}
IsWeakInstanceOfConditional.Create(scanner, ref bb, ref index, conditionalType);
return(true);
}
else if (scanner.Context.AsWeakInstanceOfMethod(target))
{
var conditionalType = genericInstance.GenericArguments [0].Resolve();
if (conditionalType == null)
{
throw new ResolutionException(genericInstance.GenericArguments [0]);
}
AsWeakInstanceOfConditional.Create(scanner, ref bb, ref index, conditionalType);
return(true);
}
else if (scanner.Context.IsTypeAvailableMethod(target))
{
var conditionalType = genericInstance.GenericArguments [0].Resolve();
if (conditionalType == null)
{
throw new ResolutionException(genericInstance.GenericArguments [0]);
}
IsTypeAvailableConditional.Create(scanner, ref bb, ref index, conditionalType);
return(true);
}
return(false);
}
if (scanner.Context.IsFeatureSupportedMethod(target))
{
IsFeatureSupportedConditional.Create(scanner, ref bb, ref index);
return(true);
}
if (scanner.Context.IsTypeNameAvailableMethod(target))
{
IsTypeAvailableConditional.Create(scanner, ref bb, ref index);
return(true);
}
if (scanner.Context.IsRequireFeatureMethod(target))
{
RequireFeatureConditional.Create(scanner, ref bb, ref index);
return(true);
}
if (scanner.Context.TryGetConstantMethod(target, out var constant))
{
ConstantCallConditional.Create(scanner, ref bb, ref index, target, constant);
return(true);
}
return(false);
}