Merge pull request #95 from OffchainLabs/hostio-code

code, code_size hostios

stylus-sdk/src/hostio.rs

@@ -28,6 +28,20 @@ extern "C" {
     /// [`BALANCE`]: https://www.evm.codes/#31
     pub fn account_balance(address: *const u8, dest: *mut u8);
 
+    /// Gets a subset of the code from the account at the given address. The semantics are identical to that
+    /// of the EVM's [`EXT_CODE_COPY`] opcode, aside from one small detail: the write to the buffer `dest` will
+    /// stop after the last byte is written. This is unlike the EVM, which right pads with zeros in this scenario.
+    /// The return value is the number of bytes written, which allows the caller to detect if this has occured.
+    ///
+    /// [`EXT_CODE_COPY`]: https://www.evm.codes/#3C
+    pub fn account_code(address: *const u8, offset: usize, size: usize, dest: *mut u8) -> usize;
+
+    /// Gets the size of the code in bytes at the given address. The semantics are equivalent
+    /// to that of the EVM's [`EXT_CODESIZE`].
+    ///
+    /// [`EXT_CODESIZE`]: https://www.evm.codes/#3B
+    pub fn account_code_size(address: *const u8) -> usize;
+
     /// Gets the code hash of the account at the given address. The semantics are equivalent
     /// to that of the EVM's [`EXT_CODEHASH`] opcode. Note that the code hash of an account without
     /// code will be the empty hash
@@ -262,6 +276,8 @@ extern "C" {
     /// bounds, but rather copies the overlapping portion. The semantics are otherwise equivalent
     /// to that of the EVM's [`RETURN_DATA_COPY`] opcode.
     ///
+    /// Returns the number of bytes written.
+    ///
     /// [`RETURN_DATA_COPY`]: https://www.evm.codes/#3e
     pub fn read_return_data(dest: *mut u8, offset: usize, size: usize) -> usize;
 

stylus-sdk/src/storage/map.rs

@@ -186,7 +186,7 @@ impl StorageKey for String {
 
 impl StorageKey for Address {
     fn to_slot(&self, root: B256) -> U256 {
-        let int: U160 = self.0.try_into().unwrap();
+        let int: U160 = self.0.into();
         int.to_slot(root)
     }
 }

stylus-sdk/src/types.rs

@@ -14,13 +14,28 @@
 //! ```
 
 use crate::hostio;
+use alloc::vec::Vec;
 use alloy_primitives::{b256, Address, B256, U256};
 
 /// Trait that allows the [`Address`] type to inspect the corresponding account's balance and codehash.
 pub trait AddressVM {
     /// The balance in wei of the account.
     fn balance(&self) -> U256;
 
+    /// The account's code.
+    ///
+    /// Returns an empty [`vec`] for [`EOAs`].
+    ///
+    /// [`EOAs`]: https://ethereum.org/en/developers/docs/accounts/#types-of-account
+    fn code(&self) -> Vec<u8>;
+
+    /// The length of the account's code in bytes.
+    ///
+    /// Returns `0` for [`EOAs`].
+    ///
+    /// [`EOAs`]: https://ethereum.org/en/developers/docs/accounts/#types-of-account
+    fn code_size(&self) -> usize;
+
     /// The codehash of the contract or [`EOA`] at the given address.
     ///
     /// [`EOA`]: https://ethereum.org/en/developers/docs/accounts/#types-of-account
@@ -37,13 +52,27 @@ pub trait AddressVM {
 impl AddressVM for Address {
     fn balance(&self) -> U256 {
         let mut data = [0; 32];
-        unsafe { hostio::account_balance(self.0.as_ptr(), data.as_mut_ptr()) };
+        unsafe { hostio::account_balance(self.as_ptr(), data.as_mut_ptr()) };
         U256::from_be_bytes(data)
     }
 
+    fn code(&self) -> Vec<u8> {
+        let size = self.code_size();
+        let mut data = Vec::with_capacity(size);
+        unsafe {
+            hostio::account_code(self.as_ptr(), 0, size, data.as_mut_ptr());
+            data.set_len(size);
+        }
+        data
+    }
+
+    fn code_size(&self) -> usize {
+        unsafe { hostio::account_code_size(self.as_ptr()) }
+    }
+
     fn codehash(&self) -> B256 {
         let mut data = [0; 32];
-        unsafe { hostio::account_codehash(self.0.as_ptr(), data.as_mut_ptr()) };
+        unsafe { hostio::account_codehash(self.as_ptr(), data.as_mut_ptr()) };
         data.into()
     }