Our wrapping optimization relied on the caller context having a TRY block,
but each context (including internal calls!) has an exception handling stack
of its own, which means that for an invocation stack of
entry
A.someMethodFromEntry() # this one has a TRY
A.internalMethodViaCALL() # this one doesn't
B.someMethod()
we get `HasTryBlock() == false` for `A.internalMethodViaCALL()` context, which
leads to missing wrapper and missing rollbacks if B is to THROW. What this
patch does instead is it checks for any context within contract boundaries.
Fixes#3045.
Signed-off-by: Roman Khimov <roman@nspcc.ru>
We don't use all of the Stack functionality for it, so drop useless methods
and avoid some interface conversions. It increases single-node TPS by about
0.9%, so nothing really important there, but not a bad change either. Maybe it
can be reworked again with generics though.
And determine the need for Null dynamically. For some reason the only dynamic
context is Contract.Call. CALLT is not dynamic and neither is a call from
native contract, go figure...
1. `System.Contract.CallNative` expects version on stack.
2. Actual method is determined based on current
instruction pointer.
3. Native hashes don't longer depend on NEF checksum.
`interop.Contex.AddMethod` sets `Safe` flag for native
contracts. This allows not to forget to change manifest
when changing call flags.
Also fixed invalid `Safe` flags for `Notary` and `Designate` contracts.
This optimizes out DB access for non-deployed contracts under the assumption
that deployed ones are always loaded via `LoadScriptWithHash` (and if they're
not --- it's a bug anyway with the new hashing model) which actually is a very
popular case (every entry script does that).
At the moment we should have 3 possible options to check return state
during vm context unloading:
* no check
* ensure the stack is empty
* ensure the stack is not empty
It is necessary to distinguish them because new _deploy method shouldn't
left anything on stack. Example: if we use _deploy method before some
ordinary contract method which returns one value. Without these changes
the contract invocation will fail due to 2 elements on stack left after
invocation (the first `null` element is from _deploy, the second element
is return-value from the ordinary contract method).
This was done in https://github.com/neo-project/neo/pull/1693
for native calls. `OnPersist` script still uses `DROP` though
as value is pushed via `CheckReturn` logic for regular calls.
