NEO VM does not distinguish between empty and nil slices. Supporting
this is not easy and requires changing lots of other opcodes.
Pointers are not supported anyway and slices can be checked for
emptiness by inspecting their `len`.
Set default value also for complex (struct, map) types.
Note: because VM does not distinguish empty array and nil array,
comparison 'a == nil' can't be handled properly without substantial
effort. This will be fixed in NEO3.
It's useless. Even though there is Neo.Transaction.GetUnspentCoins syscall
that can be used, its return type is an interop structure that's not accepted
by any other syscall, so you can't really do anything with it. And there is no
such interface for the .net Framework.
Previously we could generate dynamic appcall with a kludge of
AppCall([]byte{/* 20 zeroes */, realScriptHash, args...)
Now there is a separate function for this.
A part of integration with NEO Blockchain Toolkit (see #902). To be
able to deploy smart-contract compiled with neo-go compiler via NEO
Express, we have to generate additional .abi.json file. This file
contains the following information:
- hash of the compiled contract
- smart-contract metadata (title, description, version, author,
email, has-storage, has-dynamic-invoke, is-payable)
- smart-contract entry point
- functions
- events
However, this .abi.json file is slightly different from the one,
described in manifest.go, so we have to add auxilaury stractures for
json marshalling. The .abi.json format used by NEO-Express is described
[here](https://github.com/neo-project/neo-devpack-dotnet/blob/master/src/Neo.Compiler.MSIL/FuncExport.cs#L66).
Method `methodInfoFromScope(...)` always returned an empty parameters
set, so we were missing this information in both .abi.json and
.debug.json files. Fixed now.
Sequence points is a way to map a specific instruction offset
from a compiled contract to a text span in a source file.
This commit implements mapping only for `return` statements.
Further improvements are straight-forward.
Previously, struct variables were initialize with VM's nil value
which is of primitive type. Thus SETITEM used for struct's field
updating wasn't working.
Previously this declarations were ignored which resulted
in runtime errors, because VM's nil is an element of primitive type
and can't be converted to an array.
When `return` or `break` statement is encountered inside
a for/range/switch statement, top stack items can be auxilliary.
They need to be cleaned up before returning from the function.
Current implementation of short-circuting is just plain wrong
as it uses `last` or `before-last` labels which meaning depend
on context. It doesn't even handle simple assignements like
`a := x == 1 && y == 2`.
This commit makes all jumps in such conditions local
and adds tests.
Closes#699, #700.
