/// <summary>
/// Takes current result and wraps it into try-filter(MethodUnwinder)-finally block that ensures correct "break" behavior for
/// library method calls with block given in bfcVariable (BlockParam).
/// </summary>
public static void RuleControlFlowBuilder(MetaObjectBuilder /*!*/ metaBuilder, CallArguments /*!*/ args)
{
if (metaBuilder.Error)
{
return;
}
var metaBlock = args.GetMetaBlock();
Debug.Assert(metaBlock != null, "RuleControlFlowBuilder should only be used if the signature has a block");
// We construct CF only for non-nil blocks thus we need a test for it:
if (metaBlock.Value == null)
{
metaBuilder.AddRestriction(Ast.Equal(metaBlock.Expression, AstUtils.Constant(null)));
return;
}
// don't need to test the exact type of the Proc since the code is subclass agnostic:
metaBuilder.AddRestriction(Ast.NotEqual(metaBlock.Expression, AstUtils.Constant(null)));
Expression bfcVariable = metaBuilder.BfcVariable;
Debug.Assert(bfcVariable != null);
// Method call with proc can invoke control flow that returns an arbitrary value from the call, so we need to type result to Object.
// Otherwise, the result could only be result of targetExpression unless its return type is void.
Expression resultVariable = metaBuilder.GetTemporary(typeof(object), "#result");
ParameterExpression unwinder;
metaBuilder.Result = Ast.Block(
Ast.Assign(bfcVariable, Methods.CreateBfcForLibraryMethod.OpCall(AstUtils.Convert(args.GetBlockExpression(), typeof(Proc)))),
AstUtils.Try(
Ast.Assign(resultVariable, AstUtils.Convert(metaBuilder.Result, typeof(object)))
).Filter(unwinder = Ast.Parameter(typeof(MethodUnwinder), "#unwinder"),
Methods.IsProcConverterTarget.OpCall(bfcVariable, unwinder),
Ast.Assign(resultVariable, Ast.Field(unwinder, MethodUnwinder.ReturnValueField)),
AstUtils.Default(typeof(object))
).Finally(
Methods.LeaveProcConverter.OpCall(bfcVariable)
),
resultVariable
);
}
/// <summary>
/// Takes current result and wraps it into try-filter(MethodUnwinder)-finally block that ensures correct "break" behavior for
/// library method calls with block given in bfcVariable (BlockParam).
/// </summary>
public static void RuleControlFlowBuilder(MetaObjectBuilder/*!*/ metaBuilder, CallArguments/*!*/ args) {
if (metaBuilder.Error) {
return;
}
var metaBlock = args.GetMetaBlock();
Debug.Assert(metaBlock != null, "RuleControlFlowBuilder should only be used if the signature has a block");
// We construct CF only for non-nil blocks thus we need a test for it:
if (metaBlock.Value == null) {
metaBuilder.AddRestriction(Ast.Equal(metaBlock.Expression, AstUtils.Constant(null)));
return;
}
// don't need to test the exact type of the Proc since the code is subclass agnostic:
metaBuilder.AddRestriction(Ast.NotEqual(metaBlock.Expression, AstUtils.Constant(null)));
Expression bfcVariable = metaBuilder.BfcVariable;
Debug.Assert(bfcVariable != null);
// Method call with proc can invoke control flow that returns an arbitrary value from the call, so we need to type result to Object.
// Otherwise, the result could only be result of targetExpression unless its return type is void.
Expression resultVariable = metaBuilder.GetTemporary(typeof(object), "#result");
ParameterExpression unwinder;
metaBuilder.Result = Ast.Block(
Ast.Assign(bfcVariable, Methods.CreateBfcForLibraryMethod.OpCall(AstUtils.Convert(args.GetBlockExpression(), typeof(Proc)))),
AstUtils.Try(
Ast.Assign(resultVariable, AstUtils.Convert(metaBuilder.Result, typeof(object)))
).Filter(unwinder = Ast.Parameter(typeof(MethodUnwinder), "#unwinder"),
Methods.IsProcConverterTarget.OpCall(bfcVariable, unwinder),
Ast.Assign(resultVariable, Ast.Field(unwinder, MethodUnwinder.ReturnValueField)),
AstUtils.Default(typeof(object))
).Finally(
Methods.LeaveProcConverter.OpCall(bfcVariable)
),
resultVariable
);
}
// Normalizes arguments: inserts self, expands splats, and inserts rhs arg.
// Adds any restrictions/conditions applied to the arguments to the given meta-builder.
internal static DynamicMetaObject[]/*!*/ NormalizeArguments(MetaObjectBuilder/*!*/ metaBuilder, CallArguments/*!*/ args,
SelfCallConvention callConvention, bool calleeHasBlockParam, bool injectMissingBlockParam) {
var result = new List<DynamicMetaObject>();
// self (instance):
if (callConvention == SelfCallConvention.SelfIsInstance) {
result.Add(args.MetaTarget);
}
// block:
if (calleeHasBlockParam) {
if (args.Signature.HasBlock) {
if (args.GetMetaBlock() == null) {
// the user explicitly passed nil as a block arg:
result.Add(RubyBinder.NullMetaObject);
} else {
// pass BlockParam:
Debug.Assert(metaBuilder.BfcVariable != null);
result.Add(new DynamicMetaObject(metaBuilder.BfcVariable, BindingRestrictions.Empty));
}
} else {
// no block passed into a method with a BlockParam:
result.Add(RubyBinder.NullMetaObject);
}
} else if (injectMissingBlockParam) {
// no block passed into a method w/o a BlockParam (we still need to fill the missing block argument):
result.Add(RubyBinder.NullMetaObject);
}
// self (parameter):
if (callConvention == SelfCallConvention.SelfIsParameter) {
result.Add(args.MetaTarget);
}
// simple arguments:
for (int i = 0; i < args.SimpleArgumentCount; i++) {
result.Add(args.GetSimpleMetaArgument(i));
}
// splat argument:
int listLength;
ParameterExpression listVariable;
if (args.Signature.HasSplattedArgument) {
var splatted = args.GetSplattedMetaArgument();
if (metaBuilder.AddSplattedArgumentTest(splatted.Value, splatted.Expression, out listLength, out listVariable)) {
// AddTestForListArg only returns 'true' if the argument is a List<object>
var list = (List<object>)splatted.Value;
// get arguments, add tests
for (int j = 0; j < listLength; j++) {
result.Add(DynamicMetaObject.Create(
list[j],
Ast.Call(listVariable, typeof(List<object>).GetMethod("get_Item"), AstUtils.Constant(j))
));
}
} else {
// argument is not an array => add the argument itself:
result.Add(splatted);
}
}
// rhs argument:
if (args.Signature.HasRhsArgument) {
result.Add(args.GetRhsMetaArgument());
}
return result.ToArray();
}
/// <summary>
/// Resolves an library method overload and builds call expression.
/// The resulting expression on meta-builder doesn't handle block control flow yet.
/// </summary>
internal static void BuildCallNoFlow(MetaObjectBuilder/*!*/ metaBuilder, CallArguments/*!*/ args, string/*!*/ name,
IList<MethodBase>/*!*/ overloads, SelfCallConvention callConvention) {
var bindingTarget = ResolveOverload(name, overloads, args, callConvention);
bool calleeHasBlockParam = bindingTarget.Success && HasBlockParameter(bindingTarget.Method);
// Allocates a variable holding BlockParam. At runtime the BlockParam is created with a new RFC instance that
// identifies the library method frame as a proc-converter target of a method unwinder triggered by break from a block.
if (args.Signature.HasBlock) {
var metaBlock = args.GetMetaBlock();
if (metaBlock.Value != null && calleeHasBlockParam) {
if (metaBuilder.BfcVariable == null) {
metaBuilder.BfcVariable = metaBuilder.GetTemporary(typeof(BlockParam), "#bfc");
}
metaBuilder.ControlFlowBuilder = RuleControlFlowBuilder;
}
// Block test - we need to test for a block regardless of whether it is actually passed to the method or not
// since the information that the block is not null is used for overload resolution.
if (metaBlock.Value == null) {
metaBuilder.AddRestriction(Ast.Equal(metaBlock.Expression, AstUtils.Constant(null)));
} else {
// don't need to test the exact type of the Proc since the code is subclass agnostic:
metaBuilder.AddRestriction(Ast.NotEqual(metaBlock.Expression, AstUtils.Constant(null)));
}
}
var actualArgs = MakeActualArgs(metaBuilder, args, callConvention, calleeHasBlockParam, true);
if (bindingTarget.Success) {
var parameterBinder = new RubyParameterBinder(args.RubyContext.Binder, args.MetaContext.Expression, args.Signature.HasScope);
metaBuilder.Result = bindingTarget.MakeExpression(parameterBinder, actualArgs);
} else {
metaBuilder.SetError(args.RubyContext.RubyBinder.MakeInvalidParametersError(bindingTarget).Expression);
}
}
internal static BindingTarget/*!*/ ResolveOverload(MetaObjectBuilder/*!*/ metaBuilder, CallArguments/*!*/ args, string/*!*/ name,
IList<MethodBase>/*!*/ overloads, SelfCallConvention callConvention, out RubyOverloadResolver/*!*/ resolver) {
resolver = new RubyOverloadResolver(metaBuilder, args, callConvention);
var bindingTarget = resolver.ResolveOverload(name, overloads, NarrowingLevel.None, NarrowingLevel.All);
bool calleeHasBlockParam = bindingTarget.Success && HasBlockParameter(bindingTarget.Method);
// At runtime the BlockParam is created with a new RFC instance that identifies the library method frame as
// a proc-converter target of a method unwinder triggered by break from a block.
if (args.Signature.HasBlock) {
var metaBlock = args.GetMetaBlock();
if (metaBlock.Value != null && calleeHasBlockParam) {
Debug.Assert(metaBuilder.BfcVariable != null);
metaBuilder.ControlFlowBuilder = RuleControlFlowBuilder;
}
// Overload resolution might not need to distinguish between nil and non-nil block.
// However, we still do since we construct CF only for non-nil blocks.
if (metaBlock.Value == null) {
metaBuilder.AddRestriction(Ast.Equal(metaBlock.Expression, AstUtils.Constant(null)));
} else {
// don't need to test the exact type of the Proc since the code is subclass agnostic:
metaBuilder.AddRestriction(Ast.NotEqual(metaBlock.Expression, AstUtils.Constant(null)));
}
}
// add restrictions used for overload resolution:
resolver.AddArgumentRestrictions(metaBuilder, bindingTarget);
return bindingTarget;
}
