/// <summary>
/// Creates an invocation block from a callee and an argument list.
/// </summary>
/// <param name="CodeGenerator">The code generator that creates this block.</param>
/// <param name="Callee">The delegate to call.</param>
/// <param name="Arguments">The argument list for the call.</param>
/// <param name="CanThrow">Tells if the invocation can throw an exception.</param>
public InvocationBlock(
ICodeGenerator CodeGenerator,
CodeBlock Callee,
IEnumerable <CodeBlock> Arguments,
bool CanThrow)
{
this.codeGen = CodeGenerator;
this.Callee = Callee;
this.Arguments = Arguments;
this.methodSignature = MethodType.GetMethod(Callee.Type);
this.retType = methodSignature.ReturnType;
this.CanThrow = CanThrow;
}
/// <inheritdoc/>
public override CodeBlock EmitThrow(LLVMCodeGenerator CodeGenerator, CodeBlock Exception)
{
// Generate something more or less like this:
//
// %1 = call i8* @__cxa_allocate_exception(i64 <sizeof(value-to-throw)>)
// %2 = bitcast i8* %1 to <typeof(value-to-throw)>*
// store i8* <value-to-throw>, <typeof(value-to-throw)>* %2
// call void @__cxa_throw(i8* %1, i8* bitcast (i8** @_ZTIPv to i8*), i8* null)
// unreachable
//
var exceptionType = Exception.Type;
var exceptionStorageSpec = new DescribedVariableMember(
"exception_storage",
PrimitiveTypes.Void.MakePointerType(PointerKind.TransientPointer));
var exceptionStorage = CodeGenerator.DeclareLocal(
new UniqueTag(exceptionStorageSpec.Name.ToString()),
exceptionStorageSpec);
var allocStmt = exceptionStorage.EmitSet(
new InvocationBlock(
CodeGenerator,
new IntrinsicBlock(CodeGenerator, IntrinsicValue.CxaAllocateException),
new CodeBlock[]
{
(CodeBlock)CodeGenerator.EmitTypeBinary(
CodeGenerator.EmitSizeOf(exceptionType),
MethodType
.GetMethod(IntrinsicValue.CxaAllocateException.Type)
.GetParameters()[0].ParameterType,
Operator.StaticCast)
},
false));
var storeStmt = CodeGenerator.EmitStoreAtAddress(
CodeGenerator.EmitTypeBinary(
exceptionStorage.EmitGet(),
exceptionType.MakePointerType(PointerKind.TransientPointer),
Operator.ReinterpretCast),
Exception);
var throwStmt = new InvocationBlock(
CodeGenerator,
new IntrinsicBlock(CodeGenerator, IntrinsicValue.CxaThrow),
new CodeBlock[]
{
(CodeBlock)exceptionStorage.EmitGet(),
(CodeBlock)CodeGenerator.EmitTypeBinary(
new IntrinsicBlock(CodeGenerator, IntrinsicValue.CxaVoidPointerRtti),
PrimitiveTypes.Void.MakePointerType(PointerKind.TransientPointer),
Operator.ReinterpretCast),
(CodeBlock)CodeGenerator.EmitTypeBinary(
CodeGenerator.EmitNull(),
PrimitiveTypes.Void.MakePointerType(PointerKind.TransientPointer),
Operator.ReinterpretCast)
},
true);
return((CodeBlock)CodeGenerator.EmitSequence(
allocStmt,
CodeGenerator.EmitSequence(
storeStmt,
CodeGenerator.EmitSequence(
throwStmt,
new UnreachableBlock(CodeGenerator, PrimitiveTypes.Void)))));
}
