fix cross platform C ffi

build-release-mac.sh

@@ -16,4 +16,5 @@ cp target/release/libcozo_c.a release/libcozo_c-${VERSION}-mac-${ARCH}.a
 cp target/release/libcozo_c.dylib release/libcozo_c-${VERSION}-mac-${ARCH}.dylib
 strip release/cozoserver-${VERSION}-mac-${ARCH}
 
-gzip release/*
+gzip release/*
+cp cozo-lib-c/cozo_c.h release/cozo_c.h

cozo-lib-c/cozo_c.h

@@ -24,7 +24,7 @@ extern "C" {
  * otherwise a pointer to a C-string containing the error message will be returned.
  * The returned C-string must be freed with `cozo_free_str`.
  */
-int8_t *cozo_open_db(const int8_t *path, int32_t *db_id);
+char *cozo_open_db(const char *path, int32_t *db_id);
 
 /**
  * Close a database.
@@ -39,7 +39,7 @@ bool cozo_close_db(int32_t id);
 /**
  * Run query against a database.
  *
- * `db_id`:      the ID representing the database to run the query.
+ * `db_id`: the ID representing the database to run the query.
  * `script_raw`: a UTF-8 encoded C-string for the CozoScript to execute.
  * `params_raw`: a UTF-8 encoded C-string for the params of the query,
  *               in JSON format. You must always pass in a valid JSON map,
@@ -52,10 +52,7 @@ bool cozo_close_db(int32_t id);
  * If `*errored` is false, then the string contains the JSON return value of the query.
  * If `*errored` is true, then the string contains the error message.
  */
-int8_t *cozo_run_query(int32_t db_id,
-                       const int8_t *script_raw,
-                       const int8_t *params_raw,
-                       bool *errored);
+char *cozo_run_query(int32_t db_id, const char *script_raw, const char *params_raw, bool *errored);
 
 /**
  * Free any C-string returned from the Cozo C API.
@@ -63,7 +60,7 @@ int8_t *cozo_run_query(int32_t db_id,
  *
  * `s`: the C-string to free.
  */
-void cozo_free_str(int8_t *s);
+void cozo_free_str(char *s);
 
 #ifdef __cplusplus
 } // extern "C"

cozo-lib-c/src/lib.rs

@@ -4,7 +4,7 @@
 #![warn(rust_2018_idioms, future_incompatible)]
 
 use std::collections::BTreeMap;
-use std::ffi::{CStr, CString};
+use std::ffi::{c_char, CStr, CString};
 use std::ptr::null_mut;
 use std::sync::atomic::{AtomicI32, Ordering};
 use std::sync::Mutex;
@@ -32,7 +32,7 @@ lazy_static! {
 /// otherwise a pointer to a C-string containing the error message will be returned.
 /// The returned C-string must be freed with `cozo_free_str`.
 #[no_mangle]
-pub unsafe extern "C" fn cozo_open_db(path: *const i8, db_id: &mut i32) -> *mut i8 {
+pub unsafe extern "C" fn cozo_open_db(path: *const c_char, db_id: &mut i32) -> *mut c_char {
     let path = match CStr::from_ptr(path).to_str() {
         Ok(p) => p,
         Err(err) => return CString::new(format!("{}", err)).unwrap().into_raw(),
@@ -82,10 +82,10 @@ pub unsafe extern "C" fn cozo_close_db(id: i32) -> bool {
 #[no_mangle]
 pub unsafe extern "C" fn cozo_run_query(
     db_id: i32,
-    script_raw: *const i8,
-    params_raw: *const i8,
+    script_raw: *const c_char,
+    params_raw: *const c_char,
     errored: &mut bool,
-) -> *mut i8 {
+) -> *mut c_char {
     let script = match CStr::from_ptr(script_raw).to_str() {
         Ok(p) => p,
         Err(err) => {
@@ -152,6 +152,6 @@ pub unsafe extern "C" fn cozo_run_query(
 ///
 /// `s`: the C-string to free.
 #[no_mangle]
-pub unsafe extern "C" fn cozo_free_str(s: *mut i8) {
+pub unsafe extern "C" fn cozo_free_str(s: *mut c_char) {
     let _ = CString::from_raw(s);
 }