refactor: cleaned ffi to remove need for hacks when building unified header for swift library (#139)

* refactor: clean FFI

* update headers

* updated docs

* fix

* fixes

* fix

Author: QuantumExplorer

dash-spv-ffi/Cargo.toml

@@ -37,4 +37,4 @@ env_logger = "0.10"
 dashcore-test-utils = { path = "../test-utils" }
 
 [build-dependencies]
-cbindgen = "0.26"
+cbindgen = "0.29"

dash-spv-ffi/FFI_API.md

@@ -536,7 +536,7 @@ Sets whether to relay transactions (currently a no-op)  # Safety - `config` must
 #### `dash_spv_ffi_config_set_restrict_to_configured_peers`
 
 ```c
-dash_spv_ffi_config_set_restrict_to_configured_peers(config: *mut FFIClientConfig, restrict: bool,) -> i32
+dash_spv_ffi_config_set_restrict_to_configured_peers(config: *mut FFIClientConfig, restrict_peers: bool,) -> i32
 ```
 
 **Description:**

dash-spv-ffi/build.rs

@@ -7,13 +7,21 @@ fn main() {
 
     std::fs::create_dir_all(&output_path).unwrap();
 
-    let config = cbindgen::Config::default();
+    // Ensure the build script reruns when header-relevant files change
+    println!("cargo:rerun-if-changed=cbindgen.toml");
+    println!("cargo:rerun-if-changed=src");
 
-    cbindgen::Builder::new()
-        .with_crate(crate_dir)
-        .with_config(config)
-        .with_language(cbindgen::Language::C)
-        .generate()
-        .expect("Unable to generate bindings")
-        .write_to_file(output_path.join("dash_spv_ffi.h"));
+    let config = cbindgen::Config::from_file("cbindgen.toml")
+        .expect("cbindgen config missing or invalid: cbindgen.toml");
+
+    match cbindgen::Builder::new().with_crate(&crate_dir).with_config(config).generate() {
+        Ok(bindings) => {
+            bindings.write_to_file(output_path.join("dash_spv_ffi.h"));
+            println!("cargo:warning=Generated C header at {:?}", output_path);
+        }
+        Err(e) => {
+            // Fail the build to avoid shipping stale headers
+            panic!("Failed to generate C header via cbindgen: {}", e);
+        }
+    }
 }

dash-spv-ffi/cbindgen.toml

@@ -11,7 +11,11 @@ cpp_compat = true
 [export]
 include = ["FFI"]
 exclude = ["Option_BlockCallback", "Option_TransactionCallback", "Option_BalanceCallback"]
-prefix = "dash_spv_ffi_"
+prefix = ""
+
+[export.body]
+# Forward-declare FFIClientConfig to avoid aliasing to internal ClientConfig in C headers
+"FFIClientConfig" = ""
 
 [export.rename]
 "FFIValidationMode" = "DashSpvValidationMode"
@@ -32,4 +36,4 @@ parse_deps = false
 include = []
 
 [macro_expansion]
-bitflags = false
+bitflags = false