Allow passing pointers across rpsl ffi.

Author: overdesigned

tools/rps_rustc/rps_rs/macro_utils/src/lib.rs

@@ -338,7 +338,7 @@ fn emit_wrapper_arg_forwarding_stmts(
         },
         Type::Ptr(ty_ptr) => {
             out_stmts.push(parse_quote!{
-                let #arg_name = unsafe { pp_args[#arg_index] as #ty_ptr };
+                let #arg_name = unsafe {*(pp_args[#arg_index] as *const #ty_ptr)};
             });
         },
         Type::Slice(_ty_slice) => {
@@ -497,21 +497,21 @@ pub fn derive_rps_ffi_type(item: TokenStream) -> TokenStream {
 
     let output = quote! {
 
-        impl RpsTypeInfoTrait for & #ident {
-            const RPS_TYPE_INFO : CRpsTypeInfo = CRpsTypeInfo {
+        impl rps_rs::rpsl_runtime::RpsTypeInfoTrait for & #ident {
+            const RPS_TYPE_INFO : rps_rs::rpsl_runtime::CRpsTypeInfo = rps_rs::rpsl_runtime::CRpsTypeInfo {
                 size: std::mem::size_of::<#ident>() as u16,
-                id: RpsBuiltInTypeIds::RPS_TYPE_OPAQUE as u16,
+                id: rps_rs::rpsl_runtime::RpsBuiltInTypeIds::RPS_TYPE_OPAQUE as u16,
             };
 
             fn to_c_ptr(&self) -> *const c_void {
                 (*self) as *const _ as *const c_void
             }
         }
 
-        impl RpsTypeInfoTrait for #ident {
-            const RPS_TYPE_INFO : CRpsTypeInfo = CRpsTypeInfo {
+        impl rps_rs::rpsl_runtime::RpsTypeInfoTrait for #ident {
+            const RPS_TYPE_INFO : rps_rs::rpsl_runtime::CRpsTypeInfo = rps_rs::rpsl_runtime::CRpsTypeInfo {
                 size: std::mem::size_of::<#ident>() as u16,
-                id: RpsBuiltInTypeIds::RPS_TYPE_OPAQUE as u16,
+                id: rps_rs::rpsl_runtime::RpsBuiltInTypeIds::RPS_TYPE_OPAQUE as u16,
             };
         }
     };

tools/rps_rustc/rps_rs/src/rps_types.rs

@@ -4,6 +4,8 @@ use core::ffi::c_void;
 
 use crate::rpsl_runtime::{RpsTypeInfoTrait, RpsBuiltInTypeIds, CRpsTypeInfo, CRpsResourceDesc};
 
+extern crate self as rps_rs;
+
 #[non_exhaustive]
 #[repr(u32)]
 #[derive(Default, Clone, Copy, PartialEq, Eq)]
@@ -877,6 +879,20 @@ impl<U: RpsTypeInfoTrait, const N: usize> RpsTypeInfoTrait for &[U; N] {
     }
 }
 
+// Treat pointers as a 2-level indirection for now
+// to allow passing arbitary Rust structures across FFI.
+// Callers must guarantee the lifetime of the pointee.
+impl<T> RpsTypeInfoTrait for *const T {
+    const RPS_TYPE_INFO : CRpsTypeInfo = CRpsTypeInfo {
+        size: std::mem::size_of::<*const T>() as _,
+        id: RpsBuiltInTypeIds::RPS_TYPE_OPAQUE as _,
+    };
+
+    fn to_c_ptr(&self) -> *const c_void {
+        self as * const _ as *const c_void
+    }
+}
+
 impl_rps_built_in_type_info!(bool, RPS_TYPE_BUILT_IN_BOOL);
 impl_rps_built_in_type_info!(i8, RPS_TYPE_BUILT_IN_INT8);
 impl_rps_built_in_type_info!(u8, RPS_TYPE_BUILT_IN_UINT8);