private void catchErrStart()
{
exType = "System.Exception";
for (int i = 0; i < tryJump.Length; i++)
{
if (startPos == tryJump[i])
{
FTypeRef typeRef = pod.typeRef(tryErr[i]);
dotnetErr = Fan.Sys.Err.fanToDotnet(typeRef.nname());
if (!typeRef.isErr())
{
exType = typeRef.nname() + "/Val";
}
break;
}
}
// close try block
errBlocks.Push(getLastTryBlock());
// use a filter if we need to "dual-check" for native exception
if (dotnetErr != null)
{
code.CodeLabel(filterStart = code.NewLabel());
CILLabel match = code.NewLabel();
CILLabel endfilter = code.NewLabel();
// check native type first
code.Inst(Op.dup);
code.TypeInst(TypeOp.isinst, emitter.findType(dotnetErr));
code.Inst(Op.ldnull);
code.Branch(BranchOp.bne_un_s, match);
// then check Fantom type
code.Inst(Op.dup);
code.TypeInst(TypeOp.isinst, emitter.findType(exType));
code.Inst(Op.ldnull);
code.Branch(BranchOp.bne_un_s, match);
// no match
code.Inst(Op.pop); // pop exception off stack
code.IntInst(IntOp.ldc_i4, 0);
code.Branch(BranchOp.br_s, endfilter);
// match
code.CodeLabel(match);
code.Inst(Op.pop); // pop exception off stack
code.IntInst(IntOp.ldc_i4, 1);
// endfilter
code.CodeLabel(endfilter);
code.Inst(Op.endfilter);
}
// start handler block
code.StartBlock();
// there is already a System.Exception on the stack, but
// we need to map into a sys::Err type
if (parent.ErrMake == null)
{
parent.ErrMake = emitter.findMethod("Fan.Sys.Err", "make",
new string[] { "System.Exception" }, "Fan.Sys.Err");
}
code.MethInst(MethodOp.call, parent.ErrMake);
cast();
}
