From b63a29ee34157eabf18285b16502234050b4840b Mon Sep 17 00:00:00 2001
From: Shoham Chakraborty <shhmchk@gmail.com>
Date: Fri, 14 Apr 2023 14:19:51 +0800
Subject: [PATCH] evm: Enable C++ FFI (#1912)

* Enable C++ FFI

* Rename evm_ffi to ffi_exports

* Update Makefile.am
---
 lib/ain-cpp-imports/build.rs                  | 27 +++++++++++++++++++
 lib/ain-cpp-imports/build.rs.disabled         | 13 ---------
 lib/ain-cpp-imports/src/lib.rs                | 24 ++++++++---------
 src/Makefile.am                               |  4 +--
 .../{evm_ffi.cpp => ffi_exports.cpp}          |  2 +-
 src/masternodes/{evm_ffi.h => ffi_exports.h}  |  0
 6 files changed, 42 insertions(+), 28 deletions(-)
 create mode 100644 lib/ain-cpp-imports/build.rs
 delete mode 100644 lib/ain-cpp-imports/build.rs.disabled
 rename src/masternodes/{evm_ffi.cpp => ffi_exports.cpp} (81%)
 rename src/masternodes/{evm_ffi.h => ffi_exports.h} (100%)

diff --git a/lib/ain-cpp-imports/build.rs b/lib/ain-cpp-imports/build.rs
new file mode 100644
index 00000000000..96065f60564
--- /dev/null
+++ b/lib/ain-cpp-imports/build.rs
@@ -0,0 +1,27 @@
+use std::env;
+use std::path::PathBuf;
+
+fn main() {
+    let manifest_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+    let lib_path = &manifest_path
+        .parent()
+        .unwrap()
+        .parent()
+        .unwrap()
+        .join("src");
+
+    cxx_build::bridge("src/lib.rs")
+        .include(lib_path)
+        .flag_if_supported("-std=c++17")
+        .flag_if_supported("-Wno-unused-parameter")
+        .compile("ain-evm-cpp-ffi");
+
+    println!(
+        "cargo:rerun-if-changed={}/lib.rs",
+        lib_path.to_str().unwrap()
+    );
+    println!(
+        "cargo:rerun-if-changed={}/masternodes/ffi_exports.h",
+        lib_path.to_str().unwrap()
+    );
+}
diff --git a/lib/ain-cpp-imports/build.rs.disabled b/lib/ain-cpp-imports/build.rs.disabled
deleted file mode 100644
index 3f7c31f1dfd..00000000000
--- a/lib/ain-cpp-imports/build.rs.disabled
+++ /dev/null
@@ -1,13 +0,0 @@
-fn main() {
-    cxx_build::bridge("src/lib.rs")
-        .include("../../../../depends/x86_64-pc-linux-gnu/include/")
-        .include("../../../")
-        .include("../../../leveldb/include/")
-        .include("../../../univalue/include/")
-        .flag_if_supported("-std=c++17")
-        .flag_if_supported("-Wno-unused-parameter")
-        .compile("ain-evm-cpp-ffi");
-
-    println!("cargo:rerun-if-changed=src/lib.rs");
-    println!("cargo:rerun-if-changed=../../../masternodes/evm_ffi.h");
-}
diff --git a/lib/ain-cpp-imports/src/lib.rs b/lib/ain-cpp-imports/src/lib.rs
index d7484dff746..408d1126ec7 100644
--- a/lib/ain-cpp-imports/src/lib.rs
+++ b/lib/ain-cpp-imports/src/lib.rs
@@ -1,21 +1,21 @@
 use std::error::Error;
 
-// #[cxx::bridge]
-// mod ffi {
-//     unsafe extern "C++" {
-//         include!("masternodes/evm_ffi.h");
+#[cxx::bridge]
+mod ffi {
+    unsafe extern "C++" {
+        include!("masternodes/ffi_exports.h");
 
-//         fn getChainId() -> u64;
-//         fn isMining() -> bool;
-//     }
-// }
+        fn getChainId() -> u64;
+        fn isMining() -> bool;
+    }
+}
 
 pub fn get_chain_id() -> Result<u64, Box<dyn Error>> {
-    // let chain_id = ffi::getChainId();
-    Ok(0)
+    let chain_id = ffi::getChainId();
+    Ok(chain_id)
 }
 
 pub fn is_mining() -> Result<bool, Box<dyn Error>> {
-    // let is_mining = ffi::isMining();
-    Ok(true)
+    let is_mining = ffi::isMining();
+    Ok(is_mining)
 }
diff --git a/src/Makefile.am b/src/Makefile.am
index 82579416155..6ba1a65dae8 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -164,7 +164,7 @@ DEFI_CORE_H = \
   masternodes/communityaccounttypes.h \
   masternodes/errors.h \
   masternodes/evm.h \
-  masternodes/evm_ffi.h \
+  masternodes/ffi_exports.h \
   masternodes/factory.h \
   masternodes/govvariables/attributes.h \
   masternodes/govvariables/icx_takerfee_per_btc.h \
@@ -396,7 +396,7 @@ libdefi_server_a_SOURCES = \
   masternodes/accountshistory.cpp \
   masternodes/anchors.cpp \
   masternodes/auctionhistory.cpp \
-  masternodes/evm_ffi.cpp \
+  masternodes/ffi_exports.cpp \
   masternodes/govvariables/attributes.cpp \
   masternodes/govvariables/icx_takerfee_per_btc.cpp \
   masternodes/govvariables/loan_daily_reward.cpp \
diff --git a/src/masternodes/evm_ffi.cpp b/src/masternodes/ffi_exports.cpp
similarity index 81%
rename from src/masternodes/evm_ffi.cpp
rename to src/masternodes/ffi_exports.cpp
index 27c57d417a3..72d84f308b0 100644
--- a/src/masternodes/evm_ffi.cpp
+++ b/src/masternodes/ffi_exports.cpp
@@ -1,4 +1,4 @@
-#include <masternodes/evm_ffi.h>
+#include <masternodes/ffi_exports.h>
 #include <util/system.h>
 
 uint64_t getChainId() {
diff --git a/src/masternodes/evm_ffi.h b/src/masternodes/ffi_exports.h
similarity index 100%
rename from src/masternodes/evm_ffi.h
rename to src/masternodes/ffi_exports.h