Throw opcode - inconsistent stack pop behaviour

[Novakov]

According to ECMA 335 (III.4.31) throw opcode pops exception object from stack, than discards any remaining values from stack leaving it empty. However, OpCodes.Throw field tells that stack pop behaviour is Popref, which suggests that it pops only one value from stack (possibly leaving it non-empty). Running PEVerify on assembly with following method:

.method public hidebysig 
    instance int32 Method (
        object 'value'
    ) cil managed 
{
    // Method begins at RVA 0x2050
    // Code size 31 (0x1f)
    .maxstack 8

    IL_0000: ldarg.1
    IL_0001: isinst [mscorlib]System.String
    IL_0006: dup
    IL_0007: brtrue.s IL_0019

    IL_0009: ldstr "Not a string"
    IL_000e: ldstr "value"
    IL_0013: newobj instance void [mscorlib]System.ArgumentException::.ctor(string, string)
    IL_0018: throw

    IL_0019: callvirt instance int32 [mscorlib]System.String::get_Length()
    IL_001e: ret
} // end of method Class1::Method

gives no error, which conforms to ECMA docs.

So, it would be more consistent for throw opcode to define stack pop as Varpop rather than Popref

[dotnet-policy-service]

Due to lack of recent activity, this issue has been marked as a candidate for backlog cleanup. It will be closed if no further activity occurs within 14 more days. Any new comment (by anyone, not necessarily the author) will undo this process.

This process is part of our issue cleanup automation.

[dotnet-policy-service]

This issue will now be closed since it had been marked no-recent-activity but received no further activity in the past 14 days. It is still possible to reopen or comment on the issue, but please note that the issue will be locked if it remains inactive for another 30 days.