feat: don't generate A instructions (#37)

A instructions are only supported after ckb 2023 hardfork. It's not
supported on ckb testnet or mainnet now.

So we use some compiler and linking hacks to avoid generating A
instructions. See
https://github.com/xxuejie/ckb-contract-bytes-without-a/ for a more
detailed explanation.

.cargo/config.toml

@@ -1,2 +1,5 @@
 [build]
 target = "riscv64imac-unknown-none-elf"
+rustflags = [
+  "-C", "target-feature=-a"
+]

.github/workflows/ci.yaml

@@ -9,7 +9,7 @@ defaults:
     shell: bash
 env:
   CARGO_TERM_COLOR: always
-  RUSTFLAGS: -D warnings
+  RUSTFLAGS: -D warnings -C target-feature=-a
   RUST_BACKTRACE: full
   RUST_TOOLCHAIN: 1.68.2
 jobs:

Cargo.toml

@@ -1,6 +1,7 @@
 [workspace]
 resolver = "2"
 members = [
+    "crates/atomics-polyfill",
     "contracts/eth_light_client/client_type_lock",
     "contracts/eth_light_client/mock_business_type_lock",
     "contracts/eth_light_client/verify_bin",

contracts/eth_light_client/verify_bin/Cargo.toml

@@ -10,6 +10,8 @@ repository = "https://github.com/synapseweb3/ibc-ckb-contracts"
 
 [dependencies]
 ckb-std = "0.13.0"
+atomics-polyfill = { path = "../../../crates/atomics-polyfill" }
+
 [dependencies.eth_light_client_in_ckb-verification]
 version = "0.3.0-alpha"
 git = "https://github.com/synapseweb3/eth-light-client-in-ckb"

contracts/eth_light_client/verify_bin/src/main.rs

@@ -16,6 +16,8 @@ use ckb_std::default_alloc;
 ckb_std::entry!(program_entry);
 default_alloc!();
 
+atomics_polyfill::use_atomics_polyfill!();
+
 fn program_entry() -> i8 {
     match entry::main() {
         Ok(_) => 0,

contracts/ics/base/Cargo.toml

@@ -11,3 +11,4 @@ ckb-std = "0.13.0"
 ckb-ics-axon = { git = "https://github.com/synapseweb3/ckb-ics.git", rev = "4e89e76d16" }
 rlp = { version = "0.5.2", default-features = false }
 tiny-keccak = { version = "2.0.2", features = ["keccak"] }
+atomics-polyfill = { path = "../../../crates/atomics-polyfill" }

contracts/ics/base/src/lib.rs

@@ -1,6 +1,8 @@
 #![no_std]
 extern crate alloc;
 
+atomics_polyfill::use_atomics_polyfill!();
+
 pub mod error;
 pub mod handler;
 pub mod utils;

crates/atomics-polyfill/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "atomics-polyfill"
+version = "0.1.0"
+edition = "2021"
+license = "MIT"
+homepage = "https://github.com/synapseweb3/ibc-ckb-contracts"
+repository = "https://github.com/synapseweb3/ibc-ckb-contracts"
+
+[lib]
+
+[build-dependencies]
+cc = "1.0.83"

crates/atomics-polyfill/README.md

@@ -0,0 +1 @@
+Inspired by https://github.com/xxuejie/ckb-contract-bytes-without-a/

crates/atomics-polyfill/build.rs

@@ -0,0 +1,23 @@
+fn main() {
+    // let clang = match std::env::var_os("CLANG") {
+    //     Some(val) => val,
+    //     None => "clang-16".into(),
+    // };
+
+    cc::Build::new()
+        .file("src/atomics.c")
+        .static_flag(true)
+        // .compiler(clang)
+        .no_default_flags(true)
+        // .flag("--target=riscv64")
+        .flag("-march=rv64imc")
+        .flag("-O3")
+        .flag("-fvisibility=hidden")
+        .flag("-fdata-sections")
+        .flag("-ffunction-sections")
+        .flag("-Wall")
+        .flag("-Werror")
+        .flag("-Wno-unused-parameter")
+        .define("__SHARED_LIBRARY__", None)
+        .compile("atomics-polyfill");
+}