Turn `Config` into a C struct instead of an opaque struct

We want to be able to access the fields in `Config`, so make them
accessible across the FFI boundary.

* Return a regular, not boxed, `Config` from `parse_args()`.
* Add `repr(C)`s on our structs (had forgotten how this worked in
  961b3b0b2d33a2c632fbc093b61e2c2d4dc07f70).
* Delete the `config_free()` function as I think the stuct doesn't need
  to be freed being a POD struct. Hopefully that's the case.

3 files changed, 12 insertions, 13 deletions

diff --git a/dome_key_map.h b/dome_key_map.h
index 39ba298..74369b7 100644
--- a/dome_key_map.h
+++ b/dome_key_map.h
@@ -17,8 +17,6 @@ typedef enum {
   MapKind_Command,
 } MapKind;
 
-typedef struct Config Config;
-
 typedef struct State State;
 
 typedef struct {
@@ -26,9 +24,16 @@ typedef struct {
   size_t length;
 } Trigger;
 
-void c_run_key_action(State *state, Trigger trigger, const Trigger *mode);
+typedef struct {
+  bool reload;
+  bool daemon;
+} Args;
 
-void config_free(Config *ptr);
+typedef struct {
+  Args args;
+} Config;
+
+void c_run_key_action(State *state, Trigger trigger, const Trigger *mode);
 
 void logger_init(void);
 
diff --git a/src/cocoa_bridge.rs b/src/cocoa_bridge.rs
index f572c37..529fb5d 100644
--- a/src/cocoa_bridge.rs
+++ b/src/cocoa_bridge.rs
@@ -319,13 +319,7 @@ pub extern "C" fn parse_args(
 
     let config = config::parse_args(&args);
 
-    Box::into_raw(Box::new(config)) as *const Config
-}
-
-#[no_mangle]
-pub extern "C" fn config_free(ptr: *mut Config) {
-    if ptr.is_null() { return }
-    unsafe { Box::from_raw(ptr); }
+    &config as *const Config
 }
 
 
diff --git a/src/config.rs b/src/config.rs
index 66769a9..b7b09ab 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,13 +1,13 @@
 use getopts::Options;
 
-#[no_mangle]
+#[repr(C)]
 #[derive(Default)]
 struct Args {
     reload: bool,
     daemon: bool,
 }
 
-#[no_mangle]
+#[repr(C)]
 #[derive(Default)]
 pub struct Config {
     args: Args,