Merge pull request #9 from charlie-g-cowan/cleanup

.eslintignore

@@ -0,0 +1,2 @@
+/node_modules
+.huff

.eslintrc.js

@@ -0,0 +1,51 @@
+module.exports = {
+    "extends": "airbnb-base",
+    "env": {
+        "mocha": true,
+        "node": true,
+        "browser": true
+    },
+    "rules": {
+        "strict": 0,
+        "arrow-body-style": 0,
+        "comma-dangle": [
+            "error",
+            {
+                "arrays": "always-multiline",
+                "objects": "always-multiline",
+                "imports": "always-multiline",
+                "exports": "always-multiline",
+                "functions": "never"
+            }
+        ],
+        "import/no-extraneous-dependencies": 0,
+        "indent": [
+            "error",
+            4,
+            {
+                "SwitchCase": 1
+            }
+        ],
+        "linebreak-style": 0,
+        "no-console": 0,
+        "no-underscore-dangle": [
+            "error",
+            {
+                "allow": [
+                    "_id"
+                ]
+            }
+        ],
+        "prefer-template": 0,
+        "max-len": [
+            "warn",
+            130,
+            {
+                "ignoreComments": true
+            },
+            {
+                "ignoreTrailingComments": true
+            }
+        ]
+    }
+};

.gitignore

@@ -1,2 +1,3 @@
 node_modules
-.nyc_output
+.nyc_output
+yarn.lock

.npmignore

@@ -0,0 +1,6 @@
+node_modules
+example
+testData
+*.spec.js
+.eslintignore
+.eslintrc.js

README.md

@@ -182,3 +182,8 @@ console.log('macro return data = ', returnValue);
 console.log('output stack state = ', stack);
 console.log('output memory state = ', memory);
 ```
+
+### **Testing**
+
+Tests can be run with `yarn test`. Example contracts, such as the ERC20 implementation, can be tested with `yarn exampletest`.
+

example/erc20/README.md

@@ -0,0 +1,17 @@
+## Mintable ERC20 implementation in Huff
+
+This is an ERC20 contract implemented in Huff to demonstrate the language's (very basic) syntax. It consists of three files:
+
+| filename             | description                                                                                                     |
+| -------------------- | --------------------------------------------------------------------------------------------------------------- |
+| `erc20.huff`         | Huff source file                                                                                                |
+| `erc20_interface.js` | JavaScript methods allowing the user to easily run Huff macros corresponding to ERC20 methods (e.g. `transfer`) |
+| `erc20.spec.js`      | Unit tests -- the Huff code really works!                                                                       |
+
+(Example unit tests can be run from `/huff/` with `yarn exampletest`.)
+
+The process by which the Huff code was created is documented in a series of blog posts on Medium:
+1. [About Huff, constructor, and function selector](https://medium.com/aztec-protocol/from-zero-to-nowhere-smart-contract-programming-in-huff-1-2-ba2b6de7fa83)
+2. [Events, mappings, and `transfer`](https://medium.com/aztec-protocol/from-zero-to-nowhere-smart-contract-programming-in-huff-2-3-5438ef7e5beb)
+3. [`totalSupply`, `balanceOf`, and `mint`](https://medium.com/aztec-protocol/from-zero-to-nowhere-smart-contract-programming-in-huff-3-4-6b347e23d66e)
+4. [Nested mappings, `allowance`, `approve`, and `transferFrom`](https://medium.com/aztec-protocol/from-zero-to-nowhere-smart-contract-programming-in-huff-4-4-9e6c34648992)

example/erc20/erc20.huff

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+#define macro BALANCE_LOCATION = takes(0) returns(1) {
+	0x00 // do not change!
+}
+
+#define macro OWNER_LOCATION = takes(0) returns(1) {
+	0x01
+}
+
+#define macro TOTAL_SUPPLY_LOCATION = takes(0) returns(1) {
+	0x02
+}
+
+#define macro ALLOWANCE_LOCATION = takes(0) returns(1) {
+	0x03
+}
+
+#define macro ADDRESS_MASK = takes(1) returns(1) {
+	0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff
+	and
+}
+
+#define macro TRANSFER_EVENT_SIGNATURE = takes(0) returns(1) {
+	0xDDF252AD1BE2C89B69C2B068FC378DAA952BA7F163C4A11628F55A4DF523B3EF
+}
+
+#define macro APPROVAL_EVENT_SIGNATURE = takes(0) returns(1) {
+	0x8C5BE1E5EBEC7D5BD14F71427D1E84F3DD0314C0F7B2291E5B200AC8C7C3B925
+}
+
+template <error_location>
+#define macro UTILS__NOT_PAYABLE = takes(0) returns(0) {
+	callvalue <error_location> jumpi
+}
+
+#define macro UTILS__ONLY_OWNER = takes(0) returns(0) {
+	OWNER_LOCATION() sload caller eq is_owner jumpi
+		0x00 0x00 revert
+	is_owner:
+}
+
+#define macro ERC20 = takes(0) returns(0) {
+	caller OWNER_LOCATION() sstore
+}
+
+template <transfer, transfer_from, balance_of, allowance, approve, total_supply, mint, error_location>
+#define macro ERC20__FUNCTION_SIGNATURE = takes(0) returns(0) {
+	0x00 calldataload 224 shr // function signature
+	dup1 0x095ea7b3 eq <approve> jumpi
+	dup1 0x18160ddd eq <total_supply> jumpi
+	dup1 0x23b872dd eq <transfer_from> jumpi
+	dup1 0x40c10f19 eq <mint> jumpi
+	dup1 0x70a08231 eq <balance_of> jumpi
+	dup1 0xa9059cbb eq <transfer> jumpi
+	dup1 0xdd62ed3e eq <allowance> jumpi
+	UTILS__NOT_PAYABLE<error_location>()
+	0x00 0x00 return
+}
+
+#define macro ERC20__TRANSFER_INIT = takes(0) returns(6) {
+	0x04 calldataload ADDRESS_MASK()
+	caller
+	TRANSFER_EVENT_SIGNATURE()
+	0x20
+	0x00
+	0x24 calldataload
+	// value 0x00 0x20 signature from to
+}
+
+#define macro ERC20__TRANSFER_GIVE_TO = takes(6) returns(7) {
+	// value 0x00 0x20 signature from to
+	dup6 0x00 mstore
+	0x40 0x00 sha3
+	// key(balances[to]) value 0x00 0x20 signature from to
+	dup1 sload
+	// balances[to] key value 0x00 0x20 signature from to
+	dup3   // v b k v 0x00 0x20 sig f t
+	add    // v+b k v 0x00 0x20 sig f t
+	dup1   // v+b v+b k v 0x00 0x20 sig f t
+	dup4   // v v+b v+b k v 0x00 0x20 sig f t
+	gt     // v>v+b v+b k v 0x00 0x20 sig f t
+	swap2  // k v+b v>v+b v 0x00 0x20 sig f t
+	sstore // v>v+b v 0x00 0x20 sig f t
+}
+
+template <from>
+#define macro ERC20__TRANSFER_TAKE_FROM = takes(7) returns(8) {
+	// error_code value 0x00 0x20 signature from to
+	<from> 0x00 mstore
+	0x40 0x00 sha3
+	// key(balances[from]) error_code value 0x00 0x20 signature from to
+	dup1 sload // balances[from] key error value 0x00 0x20 sig f t
+			   // b k e1 v 0 2 s f t
+	dup4 dup2  // b v b k e1 v 0 2 s f t
+	sub dup5   // v (b-v) b k e1 v 0 2 s f t
+	swap3      // k (b-v) b v e1 v 0 2 s f t
+	sstore     // b v e1 v 0 2 s f t
+	lt         // error2 error1 value 0x00 0x20 signature from to
+}
+
+template <error_location>
+#define macro ERC20__TRANSFER = takes(0) returns(0) {
+	ERC20__TRANSFER_INIT()
+	ERC20__TRANSFER_GIVE_TO()
+	ERC20__TRANSFER_TAKE_FROM<caller>()
+	// error2 error1 value 0x00 0x20 signature from to
+	callvalue or or <error_location> jumpi
+	// value 0x00 0x20 signature from to
+	0x00 mstore // value must be stored at 0x00
+	log3
+	0x01 0x00 mstore
+	0x20 0x00 return
+}
+
+#define macro ERC20__TRANSFER_FROM_INIT = takes(0) returns(6) {
+	0x24 calldataload ADDRESS_MASK() // stack: to
+	0x04 calldataload ADDRESS_MASK() // stack: from to
+	TRANSFER_EVENT_SIGNATURE()
+	0x20
+	0x00
+	0x44 calldataload
+	// stacK: value 0x00 0x20 signature from to
+}
+
+#define macro ERC20__TRANSFER_SUB_ALLOWANCE = takes(8) returns (9) {
+	// stack: error2 error1 value 0x00 0x20 signature from to
+	dup7 0x00 mstore
+	ALLOWANCE_LOCATION() 0x20 mstore
+	0x40 0x00 sha3
+	0x20 mstore
+	caller 0x00 mstore
+	0x40 0x00 sha3
+	// stack: key(allowances[from][msg.sender]) error2 error1 value 0x00 0x20 signature from to
+	dup1 sload // allowance key e2 e1 v 0x00 0x20 s f t
+	dup5 dup2 // a v a k e2 e1 v 0 2 s f t
+	sub dup6 // v a-v a k e2 e1 v 0 2 s f t
+	swap3 sstore // a v e2 e1 v 0 2 s f t
+	lt // stack: error3 error2 error1 value 0x00 0x20 signature from to
+}
+
+template <error_location>
+#define macro ERC20__TRANSFER_FROM = takes(0) returns(0) {
+	ERC20__TRANSFER_FROM_INIT()
+	ERC20__TRANSFER_GIVE_TO()
+	ERC20__TRANSFER_TAKE_FROM<dup6>()
+	ERC20__TRANSFER_SUB_ALLOWANCE()
+	// error3 error2 error1 value 0x00 0x20 signature from to
+	callvalue or or or <error_location> jumpi
+	// value 0x00 0x20 signature from to
+	0x00 mstore
+	log3
+	0x01 0x00 mstore
+	0x20 0x00 return
+}
+
+template <error_location>
+#define macro ERC20__BALANCE_OF = takes(0) returns(0) {
+	UTILS__NOT_PAYABLE<error_location>()
+	0x04 calldataload ADDRESS_MASK()
+	0x00 mstore
+	0x40 0x00 sha3 // stacK: key(balances[owner])
+	sload // stack: balances[owner]
+	0x00 mstore
+	0x20 0x00 return
+}
+
+template <error_location>
+#define macro ERC20__ALLOWANCE = takes(0) returns(0) {
+	UTILS__NOT_PAYABLE<error_location>()
+	0x04 calldataload ADDRESS_MASK()
+	0x00 mstore
+	ALLOWANCE_LOCATION() 0x20 mstore
+	0x40 0x00 sha3
+	// stack: key(allowances[owner])
+	0x20 mstore
+	0x24 calldataload ADDRESS_MASK()
+	0x00 mstore
+	0x40 0x00 sha3
+	// stack: key(allowances[owner][spender])
+	sload
+	0x00 mstore
+	0x20 0x00 return
+}
+
+template <error_location>
+#define macro ERC20__APPROVE = takes(0) returns(0) {
+	UTILS__NOT_PAYABLE<error_location>()
+	0x04 calldataload ADDRESS_MASK()
+	caller
+	APPROVAL_EVENT_SIGNATURE()
+	0x20
+	0x00
+	// stack: 0x00 0x20 signature msg.sender spender
+	0x24 calldataload // get value
+	dup1
+	// stack: value value 0x00 0x20 signature msg.sender spender
+	caller 0x00 mstore
+	ALLOWANCE_LOCATION() 0x20 mstore
+	0x40 0x00 sha3
+	0x20 mstore
+	dup7 0x00 mstore
+	0x40 0x00 sha3
+	// stack: key(allowances[msg.sender][spender]) value value 0x00 0x20 signature msg.sender spender
+	sstore
+	0x00 mstore
+	// stack: 0x00 0x20 signature msg.sender spender
+	log3
+	0x01 0x00 mstore
+	0x20 0x00 return
+}
+
+template <error_location>
+#define macro ERC20__TOTAL_SUPPLY = takes(0) returns(0) {
+	UTILS__NOT_PAYABLE<error_location>()
+	TOTAL_SUPPLY_LOCATION() sload
+	0x00 mstore
+	0x20 0x00 return
+}
+
+template <error_location>
+#define macro ERC20__MINT = takes(0) returns(0) {
+	UTILS__ONLY_OWNER()
+	0x04 calldataload ADDRESS_MASK()
+	0 TRANSFER_EVENT_SIGNATURE() 0x20 0x00
+	0x24 calldataload
+	// stack: value 0x00 0x20 signature from to
+	ERC20__TRANSFER_GIVE_TO()
+	// stack: error1 value 0x00 0x20 signature from to
+	dup2 dup1
+	// stack: value value 0x00 0x20 signature from to
+	TOTAL_SUPPLY_LOCATION() sload add dup1 TOTAL_SUPPLY_LOCATION() sstore
+	lt
+	// stack: error2 error1 0x00 0x20 signature from to
+	callvalue or or <error_location> jumpi
+	log3
+	0x01 0x00 mstore
+	0x20 0x00 return
+}
+
+#define macro ERC20__MAIN = takes(0) returns(0) {
+
+	ERC20__FUNCTION_SIGNATURE<
+		transfer,
+		transfer_from,
+		balance_of,
+		allowance,
+		approve,
+		total_supply,
+		mint,
+		throw_error
+	>()
+
+	transfer:
+		ERC20__TRANSFER<throw_error>()
+	transfer_from:
+		ERC20__TRANSFER_FROM<throw_error>()
+	balance_of:
+		ERC20__BALANCE_OF<throw_error>()
+	allowance:
+		ERC20__ALLOWANCE<throw_error>()
+	approve:
+		ERC20__APPROVE<throw_error>()
+	total_supply:
+		ERC20__TOTAL_SUPPLY<throw_error>()
+	mint:
+	    ERC20__MINT<throw_error>()
+
+	throw_error:
+		0x00 0x00 revert
+
+}