From 8bc2e65c160d68a0fb5a1d2466d61c321bcf1eba Mon Sep 17 00:00:00 2001
From: debris <marek.kotewicz@gmail.com>
Date: Tue, 5 Jan 2016 20:24:43 +0100
Subject: [PATCH] distinguish between i256 and h256 on evmjit wrapper layer

---
 rust-evmjit/src/lib.rs | 44 +++++++++++++++++++++++++++++++++++-------
 src/evm/jit.rs         | 17 ++++++++--------
 2 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/rust-evmjit/src/lib.rs b/rust-evmjit/src/lib.rs
index 3f3de7f4e..de4efd6a1 100644
--- a/rust-evmjit/src/lib.rs
+++ b/rust-evmjit/src/lib.rs
@@ -20,6 +20,7 @@ use self::ffi::*;
 
 pub use self::ffi::JitReturnCode as ReturnCode;
 pub use self::ffi::JitI256 as I256;
+pub use self::ffi::JitH256 as H256;
 
 /// Component oriented safe handle to `JitRuntimeData`.
 pub struct RuntimeDataHandle {
@@ -101,7 +102,7 @@ impl Drop for ContextHandle {
 pub trait Env {
 	fn sload(&self, index: *const JitI256, out_value: *mut JitI256);
 	fn sstore(&mut self, index: *const JitI256, value: *const JitI256);
-	fn balance(&self, address: *const JitI256, out_value: *mut JitI256);
+	fn balance(&self, address: *const JitH256, out_value: *mut JitI256);
 	fn blockhash(&self, number: *const JitI256, out_hash: *mut JitI256);
 
 	fn create(&mut self,
@@ -130,7 +131,7 @@ pub trait Env {
 		   topic3: *const JitI256,
 		   topic4: *const JitI256);
 
-	fn extcode(&self, address: *const JitI256, size: *mut u64) -> *const u8;
+	fn extcode(&self, address: *const JitH256, size: *mut u64) -> *const u8;
 }
 
 /// C abi compatible wrapper for jit env implementers.
@@ -174,6 +175,7 @@ impl DerefMut for EnvHandle {
 /// ffi functions
 pub mod ffi {
 	use std::slice;
+	use std::mem;
 	use tiny_keccak::Keccak;
 	use super::*;
 
@@ -195,12 +197,31 @@ pub mod ffi {
 	}
 
 	#[repr(C)]
-	#[derive(Debug)]
+	#[derive(Debug, Copy, Clone)]
 	/// Signed 256 bit integer.
 	pub struct JitI256 {
 		pub words: [u64; 4]
 	}
 
+	#[repr(C)]
+	#[derive(Debug, Copy, Clone)]
+	/// Jit Hash
+	pub struct JitH256 {
+		pub words: [u64; 4]
+	}
+
+	impl From<JitH256> for JitI256 {
+		fn from(mut hash: JitH256) -> JitI256 {
+			unsafe {
+				{
+					let bytes: &mut [u8] = slice::from_raw_parts_mut(hash.words.as_mut_ptr() as *mut u8, 32);
+					bytes.reverse();
+				}
+				mem::transmute(hash)
+			}
+		}
+	}
+
 	#[repr(C)]
 	#[derive(Debug)]
 	/// Jit runtime data.
@@ -272,7 +293,7 @@ pub mod ffi {
 	}
 
 	#[no_mangle]
-	pub unsafe extern "C" fn env_balance(env: *const EnvHandle, address: *const JitI256, out_value: *mut JitI256) {
+	pub unsafe extern "C" fn env_balance(env: *const EnvHandle, address: *const JitH256, out_value: *mut JitI256) {
 		let env = &*env;
 		env.balance(address, out_value);
 	}
@@ -321,7 +342,7 @@ pub mod ffi {
 	}
 
 	#[no_mangle]
-	pub unsafe extern "C" fn env_extcode(env: *const EnvHandle, address: *const JitI256, size: *mut u64) -> *const u8 {
+	pub unsafe extern "C" fn env_extcode(env: *const EnvHandle, address: *const JitH256, size: *mut u64) -> *const u8 {
 		let env = &*env;
 		env.extcode(address, size)
 	}
@@ -371,6 +392,15 @@ fn ffi_test() {
 
 #[test]
 fn handle_test() {
-	let mut context = ContextHandle::new(RuntimeDataHandle::new(), EnvHandle::empty());
-	assert_eq!(context.exec(), ReturnCode::Stop);
+	unsafe {
+		let mut context = ContextHandle::new(RuntimeDataHandle::new(), &mut EnvHandle::empty());
+		assert_eq!(context.exec(), ReturnCode::Stop);
+	}
+}
+
+#[test]
+fn hash_to_int() {
+	let h = H256 { words:[0x0123456789abcdef, 0, 0, 0] };
+	let i = I256::from(h);
+	assert_eq!([0u64, 0, 0, 0xefcdab8967452301], i.words);
 }
diff --git a/src/evm/jit.rs b/src/evm/jit.rs
index 633c51ea5..c55c6d532 100644
--- a/src/evm/jit.rs
+++ b/src/evm/jit.rs
@@ -40,6 +40,12 @@ impl<'a> FromJit<&'a evmjit::I256> for Address {
 	}
 }
 
+impl<'a> FromJit<&'a evmjit::H256> for Address {
+	fn from_jit(input: &'a evmjit::H256) -> Self {
+		Address::from(H256::from_jit(&evmjit::I256::from(input.clone())))
+	}
+}
+
 impl IntoJit<evmjit::I256> for U256 {
 	fn into_jit(self) -> evmjit::I256 {
 		unsafe {
@@ -120,7 +126,7 @@ impl<'a> evmjit::Env for EnvAdapter<'a> {
 		}
 	}
 
-	fn balance(&self, address: *const evmjit::I256, out_value: *mut evmjit::I256) {
+	fn balance(&self, address: *const evmjit::H256, out_value: *mut evmjit::I256) {
 		unsafe {
 			let a = Address::from_jit(&*address);
 			let o = self.env.balance(&a);
@@ -168,14 +174,9 @@ impl<'a> evmjit::Env for EnvAdapter<'a> {
 		unimplemented!();
 	}
 
-	fn extcode(&self, address: *const evmjit::I256, size: *mut u64) -> *const u8 {
+	fn extcode(&self, address: *const evmjit::H256, size: *mut u64) -> *const u8 {
 		unsafe {
-			// bytes in this callback are reverted... do not know why
-			// it's the same in cpp implementation
-			// TODO: investigate and fix it on evmjit layer
-			let mut a = H256::from_jit(&*address);
-			a.reverse();
-			let code = self.env.extcode(&Address::from(a));
+			let code = self.env.extcode(&Address::from_jit(&*address));
 			*size = code.len() as u64;
 			let ptr = code.as_ptr();
 			mem::forget(code);