From 02972c2a52c38dd6d85a9ac8f0bab2e14fd5b299 Mon Sep 17 00:00:00 2001
From: Joshua Colvin <jcolvin@offchainlabs.com>
Date: Wed, 29 Nov 2023 14:53:22 -0700
Subject: [PATCH 01/14] Rename `memory_grow` to `pay_for_memory_grow`

---
 stylus-proc/src/methods/entrypoint.rs | 2 +-
 stylus-sdk/src/evm.rs                 | 4 ++--
 stylus-sdk/src/hostio.rs              | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/stylus-proc/src/methods/entrypoint.rs b/stylus-proc/src/methods/entrypoint.rs
index 411acf8..98f3904 100644
--- a/stylus-proc/src/methods/entrypoint.rs
+++ b/stylus-proc/src/methods/entrypoint.rs
@@ -84,7 +84,7 @@ pub fn entrypoint(attr: TokenStream, input: TokenStream) -> TokenStream {
     output.extend(quote! {
         #[no_mangle]
         pub unsafe fn mark_used() {
-            stylus_sdk::evm::memory_grow(0);
+            stylus_sdk::evm::pay_for_memory_grow(0);
             panic!();
         }
 
diff --git a/stylus-sdk/src/evm.rs b/stylus-sdk/src/evm.rs
index 5914e49..9ade581 100644
--- a/stylus-sdk/src/evm.rs
+++ b/stylus-sdk/src/evm.rs
@@ -53,8 +53,8 @@ pub fn log<T: SolEvent>(event: T) {
 
 /// This function exists to force the compiler to import this symbol.
 /// Calling it will unproductively consume gas.
-pub fn memory_grow(pages: u16) {
-    unsafe { hostio::memory_grow(pages) }
+pub fn pay_for_memory_grow(pages: u16) {
+    unsafe { hostio::pay_for_memory_grow(pages) }
 }
 
 wrap_hostio!(
diff --git a/stylus-sdk/src/hostio.rs b/stylus-sdk/src/hostio.rs
index 0e78148..7d2d861 100644
--- a/stylus-sdk/src/hostio.rs
+++ b/stylus-sdk/src/hostio.rs
@@ -221,7 +221,7 @@ extern "C" {
     /// Internally the Stylus VM forces calls to this hostio whenever new WASM pages are allocated.
     /// Calls made voluntarily will unproductively consume gas.
     #[allow(dead_code)]
-    pub fn memory_grow(pages: u16);
+    pub fn pay_for_memory_grow(pages: u16);
 
     /// Whether the current call is reentrant.
     pub fn msg_reentrant() -> bool;

From 7bef833ee0e59011e46967981984905b57ca37bd Mon Sep 17 00:00:00 2001
From: Michael Benfield <mbenfield@offchainlabs.com>
Date: Mon, 22 Jan 2024 13:07:41 -0800
Subject: [PATCH 02/14] code, code_size hostios

---
 stylus-sdk/src/evm.rs    | 18 +++++++++++++++++-
 stylus-sdk/src/hostio.rs |  8 ++++++++
 stylus-sdk/src/types.rs  | 15 +++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/stylus-sdk/src/evm.rs b/stylus-sdk/src/evm.rs
index 9ade581..ab9d633 100644
--- a/stylus-sdk/src/evm.rs
+++ b/stylus-sdk/src/evm.rs
@@ -14,7 +14,7 @@
 
 use crate::hostio::{self, wrap_hostio};
 use alloc::{vec, vec::Vec};
-use alloy_primitives::B256;
+use alloy_primitives::{Address, B256};
 use alloy_sol_types::{token::WordToken, SolEvent, TopicList};
 
 /// Emits an evm log from combined topics and data.
@@ -57,6 +57,22 @@ pub fn pay_for_memory_grow(pages: u16) {
     unsafe { hostio::pay_for_memory_grow(pages) }
 }
 
+/// Get the code associated with the given `address`.
+///
+/// Start at `offset` into the code and write at most `size` bytes.
+pub fn ext_code(address: &Address, offset: usize, size: Option<usize>) -> Vec<u8> {
+    let size = if let Some(sz) = size {
+        sz
+    } else {
+        unsafe { hostio::account_code_size(address.0.as_ptr()) }
+    };
+    let mut data = vec![0; size];
+    let size_written =
+        unsafe { hostio::account_code(address.0.as_ptr(), offset, size, data.as_mut_ptr()) };
+    data.truncate(size_written);
+    data
+}
+
 wrap_hostio!(
     /// Gets the amount of gas remaining. See [`Ink and Gas`] for more information on Stylus's compute pricing.
     ///
diff --git a/stylus-sdk/src/hostio.rs b/stylus-sdk/src/hostio.rs
index 7d2d861..9740ef2 100644
--- a/stylus-sdk/src/hostio.rs
+++ b/stylus-sdk/src/hostio.rs
@@ -28,6 +28,11 @@ extern "C" {
     /// [`BALANCE`]: https://www.evm.codes/#31
     pub fn account_balance(address: *const u8, dest: *mut u8);
 
+    /// Write the code associated with the given address into `dest`, starting
+    /// at `offset`, writing at most `size` bytes.
+    /// Returns the number of bytes written.
+    pub fn account_code(address: *const u8, offset: usize, size: usize, dest: *mut 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
@@ -36,6 +41,9 @@ extern "C" {
     /// [`EXT_CODEHASH`]: https://www.evm.codes/#3F
     pub fn account_codehash(address: *const u8, dest: *mut u8);
 
+    /// Get the size of the code associated with the given address.
+    pub fn account_code_size(address: *const u8) -> usize;
+
     /// Reads a 32-byte value from permanent storage. Stylus's storage format is identical to
     /// that of the EVM. This means that, under the hood, this hostio is accessing the 32-byte
     /// value stored in the EVM state trie at offset `key`, which will be `0` when not previously
diff --git a/stylus-sdk/src/types.rs b/stylus-sdk/src/types.rs
index eb2594e..52cc629 100644
--- a/stylus-sdk/src/types.rs
+++ b/stylus-sdk/src/types.rs
@@ -13,6 +13,9 @@
 //! let balance = account.balance();
 //! ```
 
+use alloc::vec;
+use alloc::vec::Vec;
+
 use crate::hostio;
 use alloy_primitives::{b256, Address, B256, U256};
 
@@ -21,6 +24,9 @@ pub trait AddressVM {
     /// The balance in wei of the account.
     fn balance(&self) -> U256;
 
+    /// The code of the contract at the given address.
+    fn code(&self) -> Vec<u8>;
+
     /// The codehash of the contract or [`EOA`] at the given address.
     ///
     /// [`EOA`]: https://ethereum.org/en/developers/docs/accounts/#types-of-account
@@ -41,6 +47,15 @@ impl AddressVM for Address {
         U256::from_be_bytes(data)
     }
 
+    fn code(&self) -> Vec<u8> {
+        let size = unsafe { hostio::account_code_size(self.0.as_ptr()) };
+        let mut data = vec![0; size];
+        unsafe {
+            hostio::account_code(self.0.as_ptr(), 0, size, data.as_mut_ptr());
+        }
+        data
+    }
+
     fn codehash(&self) -> B256 {
         let mut data = [0; 32];
         unsafe { hostio::account_codehash(self.0.as_ptr(), data.as_mut_ptr()) };

From 330ef7cc5aebf16b7ce0b5c5abeef6b85bbb66e2 Mon Sep 17 00:00:00 2001
From: Michael Benfield <mbenfield@offchainlabs.com>
Date: Thu, 25 Jan 2024 11:34:17 -0800
Subject: [PATCH 03/14] SolidityError derive macro

---
 examples/erc20/Cargo.lock      | 61 ++++++++++++++++++++++++++++++----
 examples/erc20/src/erc20.rs    | 13 ++------
 stylus-proc/src/lib.rs         |  6 ++++
 stylus-proc/src/storage/mod.rs | 30 ++++++++++++++++-
 4 files changed, 91 insertions(+), 19 deletions(-)

diff --git a/examples/erc20/Cargo.lock b/examples/erc20/Cargo.lock
index 7988a62..8538f33 100644
--- a/examples/erc20/Cargo.lock
+++ b/examples/erc20/Cargo.lock
@@ -19,7 +19,7 @@ checksum = "e416903084d3392ebd32d94735c395d6709415b76c7728e594d3f996f2b03e65"
 dependencies = [
  "alloy-rlp",
  "bytes",
- "cfg-if",
+ "cfg-if 1.0.0",
  "const-hex",
  "derive_more",
  "hex-literal",
@@ -137,6 +137,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -149,7 +155,7 @@ version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08849ed393c907c90016652a01465a12d86361cd38ad2a7de026c56a520cc259"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
  "cpufeatures",
  "hex",
  "serde",
@@ -294,7 +300,7 @@ version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "be4136b2a15dd319360be1c07d9933517ccf0be8f16bf62a3bee4f0d618df427"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
  "libc",
  "wasi",
 ]
@@ -368,11 +374,18 @@ version = "2.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5486aed0026218e61b8a01d5fbd5a0a134649abb71a0e53b7bc088529dced86e"
 
+[[package]]
+name = "memory_units"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8452105ba047068f40ff7093dd1d9da90898e63dd61736462e9cdda6a90ad3c3"
+
 [[package]]
 name = "mini-alloc"
 version = "0.4.2"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
+ "wee_alloc",
 ]
 
 [[package]]
@@ -623,7 +636,7 @@ version = "0.4.2"
 dependencies = [
  "alloy-primitives",
  "alloy-sol-types",
- "cfg-if",
+ "cfg-if 1.0.0",
  "convert_case 0.6.0",
  "lazy_static",
  "proc-macro2",
@@ -640,7 +653,7 @@ version = "0.4.2"
 dependencies = [
  "alloy-primitives",
  "alloy-sol-types",
- "cfg-if",
+ "cfg-if 1.0.0",
  "derivative",
  "fnv",
  "hex",
@@ -689,7 +702,7 @@ version = "3.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cb94d2f3cc536af71caac6b6fcebf65860b347e7ce0cc9ebe8f70d3e521054ef"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
  "fastrand",
  "redox_syscall",
  "rustix",
@@ -756,6 +769,40 @@ version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
+[[package]]
+name = "wee_alloc"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbb3b5a6b2bb17cb6ad44a2e68a43e8d2722c997da10e928665c72ec6c0a0b8e"
+dependencies = [
+ "cfg-if 0.1.10",
+ "libc",
+ "memory_units",
+ "winapi",
+]
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
 [[package]]
 name = "windows-sys"
 version = "0.48.0"
diff --git a/examples/erc20/src/erc20.rs b/examples/erc20/src/erc20.rs
index e3a8669..12191bc 100644
--- a/examples/erc20/src/erc20.rs
+++ b/examples/erc20/src/erc20.rs
@@ -1,4 +1,4 @@
-use alloc::{string::String, vec::Vec};
+use alloc::string::String;
 use core::marker::PhantomData;
 use stylus_sdk::{
     alloy_primitives::{Address, U256},
@@ -36,21 +36,12 @@ sol! {
     error InsufficientAllowance(address owner, address spender, uint256 have, uint256 want);
 }
 
+#[derive(SolidityError)]
 pub enum Erc20Error {
     InsufficientBalance(InsufficientBalance),
     InsufficientAllowance(InsufficientAllowance),
 }
 
-// We will soon provide a #[derive(SolidityError)] to clean this up
-impl From<Erc20Error> for Vec<u8> {
-    fn from(err: Erc20Error) -> Vec<u8> {
-        match err {
-            Erc20Error::InsufficientBalance(e) => e.encode(),
-            Erc20Error::InsufficientAllowance(e) => e.encode(),
-        }
-    }
-}
-
 // These methods aren't exposed to other contracts
 // Note: modifying storage will become much prettier soon
 impl<T: Erc20Params> Erc20<T> {
diff --git a/stylus-proc/src/lib.rs b/stylus-proc/src/lib.rs
index 2b9893b..b975245 100644
--- a/stylus-proc/src/lib.rs
+++ b/stylus-proc/src/lib.rs
@@ -264,6 +264,12 @@ pub fn derive_erase(input: TokenStream) -> TokenStream {
     storage::derive_erase(input)
 }
 
+/// For an error type `E`, implement `From<E>` for `Vec<u8>`.
+#[proc_macro_derive(SolidityError)]
+pub fn derive_solidity_error(input: TokenStream) -> TokenStream {
+    storage::derive_solidity_error(input)
+}
+
 /// Defines the entrypoint, which is where Stylus execution begins.
 /// Without it the contract will fail to pass [`cargo stylus check`][check].
 /// Most commonly this macro is used to annotate the top level storage `struct`.
diff --git a/stylus-proc/src/storage/mod.rs b/stylus-proc/src/storage/mod.rs
index 3138f1c..8781d06 100644
--- a/stylus-proc/src/storage/mod.rs
+++ b/stylus-proc/src/storage/mod.rs
@@ -5,7 +5,9 @@ use crate::storage::proc::{SolidityField, SolidityFields, SolidityStruct, Solidi
 use proc_macro::TokenStream;
 use quote::{quote, ToTokens};
 use std::mem;
-use syn::{parse_macro_input, punctuated::Punctuated, Index, ItemStruct, Token, Type};
+use syn::{
+    parse_macro_input, punctuated::Punctuated, Fields, Index, ItemEnum, ItemStruct, Token, Type,
+};
 
 mod proc;
 
@@ -223,3 +225,29 @@ pub fn derive_erase(input: TokenStream) -> TokenStream {
     };
     output.into()
 }
+
+pub fn derive_solidity_error(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as ItemEnum);
+    let name = &input.ident;
+    let mut match_arms = quote! {};
+    for variant in input.variants.iter() {
+        let variant_name = &variant.ident;
+        match variant.fields {
+            Fields::Unnamed(_) if variant.fields.len() == 1 => {}
+            _ => panic!("SolidityError: Each variant must be a tuple struct with one field"),
+        }
+        match_arms.extend(quote! {
+            #name::#variant_name(e) => e.encode(),
+        })
+    }
+    let output = quote! {
+        impl From<#name> for ::alloc::vec::Vec<u8> {
+            fn from(err: #name) -> ::alloc::vec::Vec<u8> {
+                match err {
+                    #match_arms
+                }
+            }
+        }
+    };
+    output.into()
+}

From 44ab101f5d448bb60f3864fd756faff519ad45bf Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Mon, 29 Jan 2024 22:44:47 -0700
Subject: [PATCH 04/14] improve docstrings

---
 stylus-sdk/src/hostio.rs | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/stylus-sdk/src/hostio.rs b/stylus-sdk/src/hostio.rs
index 9740ef2..82792bf 100644
--- a/stylus-sdk/src/hostio.rs
+++ b/stylus-sdk/src/hostio.rs
@@ -28,11 +28,20 @@ extern "C" {
     /// [`BALANCE`]: https://www.evm.codes/#31
     pub fn account_balance(address: *const u8, dest: *mut u8);
 
-    /// Write the code associated with the given address into `dest`, starting
-    /// at `offset`, writing at most `size` bytes.
-    /// Returns the number of bytes written.
+    /// 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
@@ -41,9 +50,6 @@ extern "C" {
     /// [`EXT_CODEHASH`]: https://www.evm.codes/#3F
     pub fn account_codehash(address: *const u8, dest: *mut u8);
 
-    /// Get the size of the code associated with the given address.
-    pub fn account_code_size(address: *const u8) -> usize;
-
     /// Reads a 32-byte value from permanent storage. Stylus's storage format is identical to
     /// that of the EVM. This means that, under the hood, this hostio is accessing the 32-byte
     /// value stored in the EVM state trie at offset `key`, which will be `0` when not previously
@@ -270,6 +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;
 

From c8951eab9b5bd61b264d192241642bf316aa466e Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Mon, 29 Jan 2024 23:49:07 -0700
Subject: [PATCH 05/14] add code_size, comments, and slight optimization

---
 stylus-sdk/src/evm.rs         | 18 +-----------------
 stylus-sdk/src/storage/map.rs |  2 +-
 stylus-sdk/src/types.rs       | 32 +++++++++++++++++++++++---------
 3 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/stylus-sdk/src/evm.rs b/stylus-sdk/src/evm.rs
index ab9d633..9ade581 100644
--- a/stylus-sdk/src/evm.rs
+++ b/stylus-sdk/src/evm.rs
@@ -14,7 +14,7 @@
 
 use crate::hostio::{self, wrap_hostio};
 use alloc::{vec, vec::Vec};
-use alloy_primitives::{Address, B256};
+use alloy_primitives::B256;
 use alloy_sol_types::{token::WordToken, SolEvent, TopicList};
 
 /// Emits an evm log from combined topics and data.
@@ -57,22 +57,6 @@ pub fn pay_for_memory_grow(pages: u16) {
     unsafe { hostio::pay_for_memory_grow(pages) }
 }
 
-/// Get the code associated with the given `address`.
-///
-/// Start at `offset` into the code and write at most `size` bytes.
-pub fn ext_code(address: &Address, offset: usize, size: Option<usize>) -> Vec<u8> {
-    let size = if let Some(sz) = size {
-        sz
-    } else {
-        unsafe { hostio::account_code_size(address.0.as_ptr()) }
-    };
-    let mut data = vec![0; size];
-    let size_written =
-        unsafe { hostio::account_code(address.0.as_ptr(), offset, size, data.as_mut_ptr()) };
-    data.truncate(size_written);
-    data
-}
-
 wrap_hostio!(
     /// Gets the amount of gas remaining. See [`Ink and Gas`] for more information on Stylus's compute pricing.
     ///
diff --git a/stylus-sdk/src/storage/map.rs b/stylus-sdk/src/storage/map.rs
index 8b25f0c..660ae6b 100644
--- a/stylus-sdk/src/storage/map.rs
+++ b/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)
     }
 }
diff --git a/stylus-sdk/src/types.rs b/stylus-sdk/src/types.rs
index 52cc629..a0ab9fb 100644
--- a/stylus-sdk/src/types.rs
+++ b/stylus-sdk/src/types.rs
@@ -13,10 +13,8 @@
 //! let balance = account.balance();
 //! ```
 
-use alloc::vec;
-use alloc::vec::Vec;
-
 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.
@@ -24,9 +22,20 @@ pub trait AddressVM {
     /// The balance in wei of the account.
     fn balance(&self) -> U256;
 
-    /// The code of the contract at the given address.
+    /// 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
@@ -43,22 +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 = unsafe { hostio::account_code_size(self.0.as_ptr()) };
-        let mut data = vec![0; size];
+        let size = self.code_size();
+        let mut data = Vec::with_capacity(size);
         unsafe {
-            hostio::account_code(self.0.as_ptr(), 0, size, data.as_mut_ptr());
+            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()
     }
 

From db5052f3f9c22007140c7820bdac12af1ee096fe Mon Sep 17 00:00:00 2001
From: Michael Benfield <mbenfield@offchainlabs.com>
Date: Wed, 7 Feb 2024 12:19:09 -0800
Subject: [PATCH 06/14] External methods that don't return Result

---
 stylus-proc/src/methods/external.rs |  7 ++-----
 stylus-sdk/src/abi/internal.rs      | 26 +++++++++++++++++++++-----
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/stylus-proc/src/methods/external.rs b/stylus-proc/src/methods/external.rs
index 848d2b5..bbe8ed4 100644
--- a/stylus-proc/src/methods/external.rs
+++ b/stylus-proc/src/methods/external.rs
@@ -155,10 +155,7 @@ pub fn external(_attr: TokenStream, input: TokenStream) -> TokenStream {
                     }
                 };
                 let result = Self::#name(#storage #(#expand_args, )* );
-                match result {
-                    Ok(result) => Some(Ok(internal::encode_return_type(result))),
-                    Err(err) => Some(Err(err.into())),
-                }
+                Some(EncodableReturnType::encode(result))
             }
         });
 
@@ -258,7 +255,7 @@ pub fn external(_attr: TokenStream, input: TokenStream) -> TokenStream {
             #[inline(always)]
             fn route(storage: &mut S, selector: u32, input: &[u8]) -> Option<stylus_sdk::ArbResult> {
                 use stylus_sdk::{function_selector, alloy_sol_types::SolType};
-                use stylus_sdk::abi::{internal, AbiType, Router};
+                use stylus_sdk::abi::{internal, internal::EncodableReturnType, AbiType, Router};
                 use alloc::vec;
 
                 #[cfg(feature = "export-abi")]
diff --git a/stylus-sdk/src/abi/internal.rs b/stylus-sdk/src/abi/internal.rs
index 8ea4d53..69863b1 100644
--- a/stylus-sdk/src/abi/internal.rs
+++ b/stylus-sdk/src/abi/internal.rs
@@ -4,16 +4,32 @@
 //! This module provides functions for code generated by `stylus-sdk-proc`.
 //! Most users shouldn't call these.
 
-use crate::{abi::AbiType, console, msg};
+use crate::{abi::AbiType, console, msg, ArbResult};
 use alloc::{vec, vec::Vec};
 use alloy_primitives::U256;
 use alloy_sol_types::SolType;
 use core::fmt;
 
-#[inline(always)]
-pub fn encode_return_type<T: AbiType>(x: T) -> Vec<u8> {
-    // coerce types into a tuple of at least 1 element
-    <(T,) as AbiType>::SolType::encode(&(x,))
+pub trait EncodableReturnType {
+    fn encode(self) -> ArbResult;
+}
+
+impl<T: AbiType> EncodableReturnType for T {
+    #[inline(always)]
+    fn encode(self) -> ArbResult {
+        // coerce types into a tuple of at least 1 element
+        Ok(<(T,) as AbiType>::SolType::encode(&(self,)))
+    }
+}
+
+impl<T: AbiType, E: Into<Vec<u8>>> EncodableReturnType for Result<T, E> {
+    #[inline(always)]
+    fn encode(self) -> ArbResult {
+        match self {
+            Ok(result) => result.encode(),
+            Err(err) => Err(err.into()),
+        }
+    }
 }
 
 #[inline(always)]

From 1af18069dfabba0b56171f404c3be45e3c482370 Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Wed, 14 Feb 2024 20:41:34 -0700
Subject: [PATCH 07/14] export infallible methods

---
 stylus-proc/src/methods/external.rs | 2 +-
 stylus-sdk/src/abi/internal.rs      | 8 +++++---
 stylus-sdk/src/storage/map.rs       | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/stylus-proc/src/methods/external.rs b/stylus-proc/src/methods/external.rs
index bbe8ed4..77b6cd9 100644
--- a/stylus-proc/src/methods/external.rs
+++ b/stylus-proc/src/methods/external.rs
@@ -1,4 +1,4 @@
-// Copyright 2022-2023, Offchain Labs, Inc.
+// Copyright 2022-2024, Offchain Labs, Inc.
 // For licensing, see https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/COPYRIGHT.md
 
 use crate::types::{self, Purity};
diff --git a/stylus-sdk/src/abi/internal.rs b/stylus-sdk/src/abi/internal.rs
index 69863b1..1ad9902 100644
--- a/stylus-sdk/src/abi/internal.rs
+++ b/stylus-sdk/src/abi/internal.rs
@@ -1,4 +1,4 @@
-// Copyright 2023, Offchain Labs, Inc.
+// Copyright 2023-2024, Offchain Labs, Inc.
 // For licensing, see https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/COPYRIGHT.md
 
 //! This module provides functions for code generated by `stylus-sdk-proc`.
@@ -58,12 +58,14 @@ pub fn failed_to_decode_arguments(err: alloy_sol_types::Error) {
 
 pub trait AbiResult {
     type OkType;
-    type ErrType;
 }
 
 impl<O, E> AbiResult for Result<O, E> {
     type OkType = O;
-    type ErrType = E;
+}
+
+impl<T: AbiType> AbiResult for T {
+    type OkType = T;
 }
 
 pub fn write_solidity_returns<T: AbiResult>(f: &mut fmt::Formatter) -> fmt::Result
diff --git a/stylus-sdk/src/storage/map.rs b/stylus-sdk/src/storage/map.rs
index 8b25f0c..660ae6b 100644
--- a/stylus-sdk/src/storage/map.rs
+++ b/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)
     }
 }

From 7524fb7b62d65c3e31a2e737a8a5565f6144bb99 Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Wed, 14 Feb 2024 21:13:36 -0700
Subject: [PATCH 08/14] fix contributor links

---
 .github/PULL_REQUEST_TEMPLATE.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 430fd37..10e5347 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -8,5 +8,5 @@ Please provide a summary of the changes and any backward incompatibilities.
 - [ ] I have read the [DCO][DCO] and ensured that these changes comply.
 - [ ] I assign this work under its [open source licensing][terms].
 
-[DCO]: licenses/DCO.txt
-[terms]: licenses/COPYRIGHT.md
+[DCO]: https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/DCO.txt
+[terms]: https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/COPYRIGHT.md

From 14647ee061c42b7f957a49e8e2b8e5fd239b07fa Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Tue, 20 Feb 2024 17:48:15 -0700
Subject: [PATCH 09/14] fix panic, add abi-export, & relocate

---
 stylus-proc/src/lib.rs                        | 27 +++++-
 stylus-proc/src/methods/error.rs              | 51 ++++++++++++
 stylus-proc/src/methods/external.rs           | 23 +++++-
 stylus-proc/src/methods/mod.rs                |  1 +
 stylus-proc/src/storage/mod.rs                | 36 +-------
 stylus-sdk/src/abi/export/internal.rs         | 82 +++++++++++++++++++
 .../src/abi/{export.rs => export/mod.rs}      |  5 +-
 stylus-sdk/src/abi/internal.rs                |  4 +-
 8 files changed, 191 insertions(+), 38 deletions(-)
 create mode 100644 stylus-proc/src/methods/error.rs
 create mode 100644 stylus-sdk/src/abi/export/internal.rs
 rename stylus-sdk/src/abi/{export.rs => export/mod.rs} (97%)

diff --git a/stylus-proc/src/lib.rs b/stylus-proc/src/lib.rs
index b975245..471b097 100644
--- a/stylus-proc/src/lib.rs
+++ b/stylus-proc/src/lib.rs
@@ -264,10 +264,33 @@ pub fn derive_erase(input: TokenStream) -> TokenStream {
     storage::derive_erase(input)
 }
 
-/// For an error type `E`, implement `From<E>` for `Vec<u8>`.
+/// Allows an error `enum` to be used in method signatures.
+///
+/// ```ignore
+/// sol! {
+///     error InsufficientBalance(address from, uint256 have, uint256 want);
+///     error InsufficientAllowance(address owner, address spender, uint256 have, uint256 want);
+/// }
+///
+/// #[derive(SolidityError)]
+/// pub enum Erc20Error {
+///     InsufficientBalance(InsufficientBalance),
+///     InsufficientAllowance(InsufficientAllowance),
+/// }
+///
+/// #[external]
+/// impl Contract {
+///     pub fn fallible_method() -> Result<(), Erc20Error> {
+///         // code that might revert
+///     }
+/// }
+/// ```
+///
+/// Under the hood, the above macro works by implementing `From<Erc20Error>` for `Vec<u8>`
+/// along with printing code for abi-export.
 #[proc_macro_derive(SolidityError)]
 pub fn derive_solidity_error(input: TokenStream) -> TokenStream {
-    storage::derive_solidity_error(input)
+    methods::error::derive_solidity_error(input)
 }
 
 /// Defines the entrypoint, which is where Stylus execution begins.
diff --git a/stylus-proc/src/methods/error.rs b/stylus-proc/src/methods/error.rs
new file mode 100644
index 0000000..cb1df47
--- /dev/null
+++ b/stylus-proc/src/methods/error.rs
@@ -0,0 +1,51 @@
+// Copyright 2024, Offchain Labs, Inc.
+// For licensing, see https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/COPYRIGHT.md
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, Fields, ItemEnum};
+
+pub fn derive_solidity_error(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as ItemEnum);
+    let name = &input.ident;
+    let mut match_arms = quote!();
+    let mut errors = vec![];
+    for variant in input.variants {
+        let variant_name = variant.ident;
+        let error = match variant.fields {
+            Fields::Unnamed(e) if variant.fields.len() == 1 => e.unnamed.first().unwrap().clone(),
+            _ => error!(variant.fields, "Variant not a 1-tuple"),
+        };
+        match_arms.extend(quote! {
+            #name::#variant_name(e) => e.encode(),
+        });
+        errors.push(error);
+    }
+    quote! {
+        impl From<#name> for ::alloc::vec::Vec<u8> {
+            fn from(err: #name) -> ::alloc::vec::Vec<u8> {
+                match err {
+                    #match_arms
+                }
+            }
+        }
+
+        impl stylus_sdk::abi::export::internal::InnerTypes for #name {
+            fn inner_types() -> Vec<stylus_sdk::abi::export::internal::InnerType> {
+                use alloc::vec;
+                use core::any::TypeId;
+                use stylus_sdk::abi::export::internal::InnerType;
+                use stylus_sdk::alloy_sol_types::SolError;
+
+                vec![
+                    #(
+                        InnerType {
+                            name: format!("error {};", <#errors as SolError>::SIGNATURE.replace(',', ", ")),
+                            id: TypeId::of::<#errors>(),
+                        }
+                    ),*
+                ]
+            }
+        }
+    }.into()
+}
diff --git a/stylus-proc/src/methods/external.rs b/stylus-proc/src/methods/external.rs
index 77b6cd9..0956b35 100644
--- a/stylus-proc/src/methods/external.rs
+++ b/stylus-proc/src/methods/external.rs
@@ -20,6 +20,7 @@ pub fn external(_attr: TokenStream, input: TokenStream) -> TokenStream {
     let mut selectors = quote!();
     let mut match_selectors = quote!();
     let mut abi = quote!();
+    let mut types = vec![];
 
     for item in input.items.iter_mut() {
         let ImplItem::Method(method) = item else {
@@ -278,6 +279,24 @@ pub fn external(_attr: TokenStream, input: TokenStream) -> TokenStream {
         return router.into();
     }
 
+    for item in input.items.iter_mut() {
+        let ImplItem::Method(method) = item else {
+            continue;
+        };
+        if let ReturnType::Type(_, ty) = &method.sig.output {
+            types.push(ty);
+        }
+    }
+
+    let type_decls = quote! {
+        let mut seen = HashSet::new();
+        for item in [].iter() #(.chain(&<#types as InnerTypes>::inner_types()))* {
+            if seen.insert(item.id) {
+                writeln!(f, "\n    {}", item.name)?;
+            }
+        }
+    };
+
     let name = match *self_ty.clone() {
         Type::Path(path) => path.path.segments.last().unwrap().ident.clone().to_string(),
         _ => error!(self_ty, "Can't generate ABI for unnamed type"),
@@ -309,12 +328,14 @@ pub fn external(_attr: TokenStream, input: TokenStream) -> TokenStream {
             fn fmt_abi(f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
                 use stylus_sdk::abi::{AbiType, GenerateAbi};
                 use stylus_sdk::abi::internal::write_solidity_returns;
-                use stylus_sdk::abi::export::{underscore_if_sol};
+                use stylus_sdk::abi::export::{underscore_if_sol, internal::InnerTypes};
+                use std::collections::HashSet;
                 #(#inherited_abis)*
                 write!(f, "interface I{}", #name)?;
                 #is_clause
                 write!(f, " {{")?;
                 #abi
+                #type_decls
                 writeln!(f, "}}")?;
                 Ok(())
             }
diff --git a/stylus-proc/src/methods/mod.rs b/stylus-proc/src/methods/mod.rs
index 256b033..d3e69d2 100644
--- a/stylus-proc/src/methods/mod.rs
+++ b/stylus-proc/src/methods/mod.rs
@@ -2,4 +2,5 @@
 // For licensing, see https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/COPYRIGHT.md
 
 pub mod entrypoint;
+pub mod error;
 pub mod external;
diff --git a/stylus-proc/src/storage/mod.rs b/stylus-proc/src/storage/mod.rs
index 8781d06..cd6b38a 100644
--- a/stylus-proc/src/storage/mod.rs
+++ b/stylus-proc/src/storage/mod.rs
@@ -1,13 +1,11 @@
-// Copyright 2023, Offchain Labs, Inc.
+// Copyright 2023-2024, Offchain Labs, Inc.
 // For licensing, see https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/COPYRIGHT.md
 
 use crate::storage::proc::{SolidityField, SolidityFields, SolidityStruct, SolidityStructs};
 use proc_macro::TokenStream;
 use quote::{quote, ToTokens};
 use std::mem;
-use syn::{
-    parse_macro_input, punctuated::Punctuated, Fields, Index, ItemEnum, ItemStruct, Token, Type,
-};
+use syn::{parse_macro_input, punctuated::Punctuated, Index, ItemStruct, Token, Type};
 
 mod proc;
 
@@ -216,38 +214,12 @@ pub fn derive_erase(input: TokenStream) -> TokenStream {
             self.#ident.erase();
         });
     }
-    let output = quote! {
+    quote! {
         impl #impl_generics stylus_sdk::storage::Erase for #name #ty_generics #where_clause {
             fn erase(&mut self) {
                 #erase_fields
             }
         }
-    };
-    output.into()
-}
-
-pub fn derive_solidity_error(input: TokenStream) -> TokenStream {
-    let input = parse_macro_input!(input as ItemEnum);
-    let name = &input.ident;
-    let mut match_arms = quote! {};
-    for variant in input.variants.iter() {
-        let variant_name = &variant.ident;
-        match variant.fields {
-            Fields::Unnamed(_) if variant.fields.len() == 1 => {}
-            _ => panic!("SolidityError: Each variant must be a tuple struct with one field"),
-        }
-        match_arms.extend(quote! {
-            #name::#variant_name(e) => e.encode(),
-        })
     }
-    let output = quote! {
-        impl From<#name> for ::alloc::vec::Vec<u8> {
-            fn from(err: #name) -> ::alloc::vec::Vec<u8> {
-                match err {
-                    #match_arms
-                }
-            }
-        }
-    };
-    output.into()
+    .into()
 }
diff --git a/stylus-sdk/src/abi/export/internal.rs b/stylus-sdk/src/abi/export/internal.rs
new file mode 100644
index 0000000..129183a
--- /dev/null
+++ b/stylus-sdk/src/abi/export/internal.rs
@@ -0,0 +1,82 @@
+// Copyright 2024, Offchain Labs, Inc.
+// For licensing, see https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/COPYRIGHT.md
+
+//! This module provides functions for code generated by `stylus-sdk-proc` for the `export-abi` command.
+//! Most users shouldn't call these.
+
+use alloy_primitives::{Address, FixedBytes, Signed, Uint};
+use core::any::TypeId;
+
+/// Represents a unique Solidity Type.
+pub struct InnerType {
+    /// Full interface string.
+    pub name: String,
+    /// Unique identifier for de-duplication when printing interfaces.
+    pub id: TypeId,
+}
+
+/// Trait for collecting structs and error types.
+pub trait InnerTypes {
+    /// Collect any structs and errors under the type.
+    /// Empty for primitives.
+    fn inner_types() -> Vec<InnerType> {
+        vec![]
+    }
+}
+
+impl<O, E> InnerTypes for Result<O, E>
+where
+    O: InnerTypes,
+    E: InnerTypes,
+{
+    fn inner_types() -> Vec<InnerType> {
+        let mut out = O::inner_types();
+        out.extend(E::inner_types());
+        out
+    }
+}
+
+impl<T: InnerTypes> InnerTypes for Vec<T> {
+    fn inner_types() -> Vec<InnerType> {
+        T::inner_types()
+    }
+}
+
+impl<const N: usize, T: InnerTypes> InnerTypes for [T; N] {
+    fn inner_types() -> Vec<InnerType> {
+        T::inner_types()
+    }
+}
+
+macro_rules! impl_inner {
+    ($ty:ident $($rest:ident)+) => {
+        impl_inner!($ty);
+        impl_inner!($($rest)+);
+    };
+    ($ty:ident) => {
+        impl InnerTypes for $ty {}
+    };
+}
+
+impl_inner!(bool u8 u16 u32 u64 u128 i8 i16 i32 i64 i128 String Address);
+
+impl<const B: usize, const L: usize> InnerTypes for Uint<B, L> {}
+impl<const B: usize, const L: usize> InnerTypes for Signed<B, L> {}
+impl<const N: usize> InnerTypes for FixedBytes<N> {}
+
+macro_rules! impl_tuple {
+    () => {
+        impl InnerTypes for () {}
+    };
+    ($first:ident $(, $rest:ident)*) => {
+        impl<$first: InnerTypes $(, $rest: InnerTypes)*> InnerTypes for ( $first $(, $rest)* , ) {
+            fn inner_types() -> Vec<InnerType> {
+                vec![]
+            }
+        }
+
+        impl_tuple! { $($rest),* }
+    };
+}
+
+impl_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X);
diff --git a/stylus-sdk/src/abi/export.rs b/stylus-sdk/src/abi/export/mod.rs
similarity index 97%
rename from stylus-sdk/src/abi/export.rs
rename to stylus-sdk/src/abi/export/mod.rs
index c81c6c5..535291c 100644
--- a/stylus-sdk/src/abi/export.rs
+++ b/stylus-sdk/src/abi/export/mod.rs
@@ -1,4 +1,4 @@
-// Copyright 2023, Offchain Labs, Inc.
+// Copyright 2023-2024, Offchain Labs, Inc.
 // For licensing, see https://github.com/OffchainLabs/stylus-sdk-rs/blob/stylus/licenses/COPYRIGHT.md
 
 //! Traits for exporting Solidity interfaces.
@@ -12,6 +12,9 @@ use core::{fmt, marker::PhantomData};
 use lazy_static::lazy_static;
 use regex::Regex;
 
+#[doc(hidden)]
+pub mod internal;
+
 /// Trait for storage types so that users can print a Solidity interface to the console.
 /// This is auto-derived via the [`external`] macro when the `export-abi` feature is enabled.
 ///
diff --git a/stylus-sdk/src/abi/internal.rs b/stylus-sdk/src/abi/internal.rs
index 1ad9902..84cb68d 100644
--- a/stylus-sdk/src/abi/internal.rs
+++ b/stylus-sdk/src/abi/internal.rs
@@ -76,8 +76,8 @@ where
     if abi == "()" {
         Ok(())
     } else if abi.starts_with('(') {
-        write!(f, " returns {}", abi)
+        write!(f, " returns {abi}")
     } else {
-        write!(f, " returns ({})", abi)
+        write!(f, " returns ({abi})")
     }
 }

From 1383cc0ee3921c14a49bdeefa679396b4fac4fa1 Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Tue, 20 Feb 2024 22:54:20 -0700
Subject: [PATCH 10/14] cfg-gate abi code

---
 stylus-proc/src/methods/error.rs | 44 ++++++++++++++++++--------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/stylus-proc/src/methods/error.rs b/stylus-proc/src/methods/error.rs
index cb1df47..5b8d3c0 100644
--- a/stylus-proc/src/methods/error.rs
+++ b/stylus-proc/src/methods/error.rs
@@ -21,31 +21,37 @@ pub fn derive_solidity_error(input: TokenStream) -> TokenStream {
         });
         errors.push(error);
     }
-    quote! {
-        impl From<#name> for ::alloc::vec::Vec<u8> {
-            fn from(err: #name) -> ::alloc::vec::Vec<u8> {
+    let mut output = quote! {
+        impl From<#name> for alloc::vec::Vec<u8> {
+            fn from(err: #name) -> alloc::vec::Vec<u8> {
                 match err {
                     #match_arms
                 }
             }
         }
+    };
 
-        impl stylus_sdk::abi::export::internal::InnerTypes for #name {
-            fn inner_types() -> Vec<stylus_sdk::abi::export::internal::InnerType> {
-                use alloc::vec;
-                use core::any::TypeId;
-                use stylus_sdk::abi::export::internal::InnerType;
-                use stylus_sdk::alloy_sol_types::SolError;
+    if cfg!(feature = "export-abi") {
+        output.extend(quote! {
+            impl stylus_sdk::abi::export::internal::InnerTypes for #name {
+                fn inner_types() -> alloc::vec::Vec<stylus_sdk::abi::export::internal::InnerType> {
+                    use alloc::{format, vec};
+                    use core::any::TypeId;
+                    use stylus_sdk::abi::export::internal::InnerType;
+                    use stylus_sdk::alloy_sol_types::SolError;
 
-                vec![
-                    #(
-                        InnerType {
-                            name: format!("error {};", <#errors as SolError>::SIGNATURE.replace(',', ", ")),
-                            id: TypeId::of::<#errors>(),
-                        }
-                    ),*
-                ]
+                    vec![
+                        #(
+                            InnerType {
+                                name: format!("error {};", <#errors as SolError>::SIGNATURE.replace(',', ", ")),
+                                id: TypeId::of::<#errors>(),
+                            }
+                        ),*
+                    ]
+                }
             }
-        }
-    }.into()
+        });
+    }
+
+    output.into()
 }

From 1a0f2a94153cf67579bcccab0a691c3b4386ccae Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Wed, 21 Feb 2024 17:41:43 -0700
Subject: [PATCH 11/14] address review comments

---
 stylus-proc/src/methods/error.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/stylus-proc/src/methods/error.rs b/stylus-proc/src/methods/error.rs
index 5b8d3c0..968837f 100644
--- a/stylus-proc/src/methods/error.rs
+++ b/stylus-proc/src/methods/error.rs
@@ -17,7 +17,7 @@ pub fn derive_solidity_error(input: TokenStream) -> TokenStream {
             _ => error!(variant.fields, "Variant not a 1-tuple"),
         };
         match_arms.extend(quote! {
-            #name::#variant_name(e) => e.encode(),
+            #name::#variant_name(e) => stylus_sdk::alloy_sol_types::SolError::encode(&e),
         });
         errors.push(error);
     }

From fff184ecf4039817112d1848c8f5688bf87f2da4 Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Fri, 23 Feb 2024 11:40:20 -0700
Subject: [PATCH 12/14] remove testnet-2 hostios

---
 stylus-sdk/src/evm.rs    |  2 +-
 stylus-sdk/src/hostio.rs | 16 +---------------
 stylus-sdk/src/types.rs  | 29 -----------------------------
 3 files changed, 2 insertions(+), 45 deletions(-)

diff --git a/stylus-sdk/src/evm.rs b/stylus-sdk/src/evm.rs
index 96e9ae4..f2b15fb 100644
--- a/stylus-sdk/src/evm.rs
+++ b/stylus-sdk/src/evm.rs
@@ -54,7 +54,7 @@ pub fn log<T: SolEvent>(event: T) {
 /// This function exists to force the compiler to import this symbol.
 /// Calling it will unproductively consume gas.
 pub fn pay_for_memory_grow(pages: u16) {
-    unsafe { hostio::pay_for_memory_grow(pages) }
+    unsafe { hostio::memory_grow(pages) }
 }
 
 wrap_hostio!(
diff --git a/stylus-sdk/src/hostio.rs b/stylus-sdk/src/hostio.rs
index 82792bf..c115630 100644
--- a/stylus-sdk/src/hostio.rs
+++ b/stylus-sdk/src/hostio.rs
@@ -28,20 +28,6 @@ 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
@@ -235,7 +221,7 @@ extern "C" {
     /// Internally the Stylus VM forces calls to this hostio whenever new WASM pages are allocated.
     /// Calls made voluntarily will unproductively consume gas.
     #[allow(dead_code)]
-    pub fn pay_for_memory_grow(pages: u16);
+    pub fn memory_grow(pages: u16);
 
     /// Whether the current call is reentrant.
     pub fn msg_reentrant() -> bool;
diff --git a/stylus-sdk/src/types.rs b/stylus-sdk/src/types.rs
index a0ab9fb..2c65cb5 100644
--- a/stylus-sdk/src/types.rs
+++ b/stylus-sdk/src/types.rs
@@ -14,7 +14,6 @@
 //! ```
 
 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.
@@ -22,20 +21,6 @@ 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
@@ -56,20 +41,6 @@ impl AddressVM for Address {
         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.as_ptr(), data.as_mut_ptr()) };

From 7e235974002886793185951b8b2648dc6cf4adf8 Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Fri, 23 Feb 2024 11:41:03 -0700
Subject: [PATCH 13/14] bump version to 0.4.3

---
 Cargo.lock | 6 +++---
 Cargo.toml | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 6d6fa83..418fc24 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -308,7 +308,7 @@ checksum = "8452105ba047068f40ff7093dd1d9da90898e63dd61736462e9cdda6a90ad3c3"
 
 [[package]]
 name = "mini-alloc"
-version = "0.4.2"
+version = "0.4.3"
 dependencies = [
  "cfg-if 1.0.0",
  "wasm-bindgen-test",
@@ -498,7 +498,7 @@ dependencies = [
 
 [[package]]
 name = "stylus-proc"
-version = "0.4.2"
+version = "0.4.3"
 dependencies = [
  "alloy-primitives",
  "alloy-sol-types",
@@ -515,7 +515,7 @@ dependencies = [
 
 [[package]]
 name = "stylus-sdk"
-version = "0.4.2"
+version = "0.4.3"
 dependencies = [
  "alloy-primitives",
  "alloy-sol-types",
diff --git a/Cargo.toml b/Cargo.toml
index b38370b..d56cda7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ members = ["stylus-sdk", "stylus-proc", "mini-alloc"]
 resolver = "2"
 
 [workspace.package]
-version = "0.4.2"
+version = "0.4.3"
 edition = "2021"
 authors = ["Offchain Labs"]
 license = "MIT OR Apache-2.0"

From 5bb4a8d686c769c375d347500aea6c054d654490 Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Fri, 23 Feb 2024 11:49:39 -0700
Subject: [PATCH 14/14] fix smoketest

---
 ci/smoke_test.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ci/smoke_test.sh b/ci/smoke_test.sh
index fa23fd4..cb9b8bd 100755
--- a/ci/smoke_test.sh
+++ b/ci/smoke_test.sh
@@ -11,4 +11,4 @@ cargo stylus new counter
 cd counter
 echo "[workspace]" >> Cargo.toml
 
-cargo stylus deploy --private-key $PRIV_KEY
+cargo stylus deploy --private-key $PRIV_KEY -e https://stylus-testnet.arbitrum.io/rpc