Integrate new asc features and a simple standard library

Author: dcodeIO

README.md

@@ -7,25 +7,8 @@ The AssemblyScript project in this repository is a proof of concept barebones "E
 1. Use [WebassemblyStudio](https://webassembly.studio/) or another IDE to bootstrap the project and edit `main.ts`.
 2. If using WebassemblyStudio, download the project code.
 3. Navigate to the top directory of the project and run `npm install`.
-4. Run `npm build` to compile the AssemblyScript source to WASM bytecode. Find the compiled `wasm.out` file in the `out/` directory. At this point you have a valid WASM binary but it's not ready to be deployed onto Ethereum just yet. You need to fix the import names and namespaces. We're working on a tool to automate this process but for now this must be done by hand.
-5. If you haven't already, download and compile the [WebAssembly binary toolkit (WABT)](https://github.com/WebAssembly/wabt):
-```
-> git clone --recursive https://github.com/WebAssembly/wabt ~/wabt
-> cd ~/wabt
-> make
-```
-6. Use WABT to convert the WASM bytecode to WAST (WebAssembly text format). This will let us edit the raw WAST.
-```
-> ~/wabt/bin/wasm2wat main.wasm > main.wast
-```
-7. Open `main.wast` in your favorite text editor. For each `import` at the top, change the `"env"` namespace to `"ethereum"` and remove the `ethereum_` from the name of the function to import. For example, this:
-```
-(import "env" "ethereum_getCallDataSize" (func $main/ethereum_getCallDataSize (type $t1)))
-```
-Should become this:
-```
-(import "ethereum" "getCallDataSize" (func $main/ethereum_getCallDataSize (type $t1)))
-```
-You now have valid ewasm-compatible WAST which is ready to be deployed to the ewasm testnet using a tool such as [ewasm-studio](https://github.com/ewasm/ewasm-studio). If you need to compile this back to WASM bytecode, you can do so using the `wabt/bin/wat2wasm` compiler.
+4. Run `npm run build` to compile the AssemblyScript source to WASM bytecode. Find the compiled `main.wasm` file in the `build/` directory. At this point you have a valid WASM binary.
+
+You now have a valid ewasm-compatible WAST which is ready to be deployed to the ewasm testnet using a tool such as [ewasm-studio](https://github.com/ewasm/ewasm-studio).
 
 Another option is to test the code using `testeth`. See [this example](https://github.com/lrettig/tests/blob/wrc20-challenge/src/GeneralStateTestsFiller/stEWASMTests/wrc20ChallengeFiller.yml) of a test filler that fully tests this code.

assembly/lib/README.md

@@ -0,0 +1 @@
+Custom Ethereum standard library.

assembly/lib/ethereum.d.ts

@@ -0,0 +1,14 @@
+// This file provides syntax highlighting for a TypeScript IDE
+
+declare function finish(dataOffset: i32, length: i32): void;
+declare function revert(dataOffset: i32, length: i32): void;
+declare function callDataCopy(resultOffset: i32, dataOffset: i32, length: i32): void;
+declare function getCallDataSize(): i32;
+declare function getCaller(dataOffset: i32): void;
+declare function storageStore(pathOffset: i32, valueOffset: i32): void;
+declare function storageLoad(pathOffset: i32, resultOffset: i32): void;
+declare function printMemHex(dataOffset: i32, length: i32): void;
+
+declare function allocate_memory(size: usize): usize;
+declare function free_memory(ptr: usize): void;
+declare function reset_memory(): void;

assembly/lib/ethereum.json

@@ -0,0 +1,10 @@
+{
+  "extends": "../../node_modules/assemblyscript/std/assembly.json",
+  "files": [
+    "../../node_modules/assemblyscript/std/assembly.d.ts",
+    "./ethereum.d.ts"
+  ],
+  "include": [
+    "./**/*.ts"
+  ]
+}

assembly/lib/ethereum.ts

@@ -0,0 +1,23 @@
+// This file sets up functions provided by the VM for use with AssemblyScript
+
+import "allocator/arena";
+
+@external("return")
+export declare function finish(dataOffset: i32, length: i32): void;
+
+export declare function revert(dataOffset: i32, length: i32): void;
+
+export declare function callDataCopy(resultOffset: i32, dataOffset: i32, length: i32): void;
+
+export declare function getCallDataSize(): i32;
+
+export declare function getCaller(dataOffset: i32): void;
+
+export declare function storageStore(pathOffset: i32, valueOffset: i32): void;
+
+export declare function storageLoad(pathOffset: i32, resultOffset: i32): void;
+
+@external("debug", "printMemHex")
+export declare function printMemHex(dataOffset: i32, length: i32): void;
+
+// TODO: need to implement a nice wrapper over the native functions which use native types and handles the memory.

assembly/lib/tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "extends": "../../node_modules/assemblyscript/std/assembly.json",
+  "include": [
+    "./**/*.ts"
+  ]
+}

assembly/main.ts

@@ -0,0 +1,74 @@
+const DEBUG = false;
+
+// ewasm main function
+export function main(): void {
+  // assume the memory is already expanded..
+  // ethereum_return(0, ethereum_callDataSize())
+
+  // Make sure we have enough args
+  if (getCallDataSize() < 4)
+    revert(0, 0);
+
+  var ptrSelector = <i32>allocate_memory(4);
+  callDataCopy(ptrSelector, 0, 4);
+  var selector = load<i32>(ptrSelector);
+  switch(selector) {
+    case 0x9993021a:
+      do_balance();
+      break;
+    case 0x5d359fbd:
+      do_transfer();
+      break;
+    default:
+      revert(0, 0);
+  }
+}
+
+function do_balance(): void {
+  if (getCallDataSize() !== 24)
+    revert(0, 0);
+
+  var ptrAddress = <i32>allocate_memory(20);
+  callDataCopy(ptrAddress, 4, 20);
+  var ptrBalance = <i32>allocate_memory(32);
+  storageLoad(ptrAddress, ptrBalance);
+  if (DEBUG) {
+    printMemHex(ptrAddress, 32);
+    printMemHex(ptrBalance, 32);
+  }
+  finish(ptrBalance, 32);
+}
+
+function do_transfer(): void {
+  if (getCallDataSize() !== 32)
+    revert(0, 0);
+
+  var ptrSender = <i32>allocate_memory(32);
+  getCaller(ptrSender);
+  var ptrRecipient = <i32>allocate_memory(32);
+  callDataCopy(ptrRecipient, 4, 20);
+  var ptrValue = <i32>allocate_memory(32);
+  callDataCopy(ptrValue, 24, 8);
+  // debug_printMemHex(ptrValue, 32);
+  var ptrSenderBalance = <i32>allocate_memory(32);
+  var ptrRecipientBalance = <i32>allocate_memory(32);
+  storageLoad(ptrSender, ptrSenderBalance);
+  storageLoad(ptrRecipient, ptrRecipientBalance);
+  if (DEBUG) {
+    printMemHex(ptrSender, 32);
+    printMemHex(ptrRecipient, 32);
+    printMemHex(ptrSenderBalance, 32);
+    printMemHex(ptrRecipientBalance, 32);
+  }
+  var senderBalance = load<i32>(ptrSenderBalance);
+  var recipientBalance = load<i32>(ptrRecipientBalance);
+  var value = load<i32>(ptrValue);
+
+  if (senderBalance < value)
+    revert(0, 0);
+
+  store<i32>(ptrSenderBalance, senderBalance - value);
+  store<i32>(ptrRecipientBalance, recipientBalance + value);
+  storageStore(ptrSender, ptrSenderBalance);
+  storageStore(ptrRecipient, ptrRecipientBalance);
+}

assembly/src/main.ts

@@ -0,0 +1,6 @@
+{
+  "extends": "../lib/ethereum.json",
+  "include": [
+    "./**/*.ts"
+  ]
+}