v1.1

README.md

@@ -224,7 +224,7 @@ csbindgen::Builder::default()
     .input_bindgen_file("src/lz4.rs")             // required
     .method_filter(|x| { x.starts_with("LZ4") } ) // optional, default: |x| !x.starts_with('_')
     .rust_method_prefix("csbindgen_")             // optional, default: "csbindgen_"
-    .rust_file_header("use super::lz4;")          // optional, default: ""
+    .rust_file_header("use super::lz4::*;")       // optional, default: ""
     .rust_method_type_path("lz4")                 // optional, default: ""
     .csharp_dll_name("lz4")                       // required
     .csharp_class_name("NativeMethods")           // optional, default: NativeMethods
@@ -369,6 +369,8 @@ Rust types will map these C# types.
 | `*const T` | `T*` |
 | `*mut *mut T` | `T**` |
 | `*const *const T` | `T**` |
+| `*mut *const T` | `T**` |
+| `*const *mut T` | `T**` |
 
 csbindgen is designed to return primitives that do not cause marshalling. It is better to convert from pointers to Span yourself than to do the conversion implicitly and in a black box. This is a recent trend, such as the addition of [DisableRuntimeMarshalling](https://learn.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.disableruntimemarshallingattribute) from .NET 7.
 
@@ -814,7 +816,53 @@ finally
 }
 ```
 
-C# to Rust would be a bit simpler to send, just pass byte* and length. In Rust, use `std::slice::from_raw_parts` to create slice. Again, the important thing is that memory allocated in Rust must release in Rust and memory allocated in C# must release in C#.
+C# to Rust would be a bit simpler to send, just pass byte* and length. In Rust, use `std::slice::from_raw_parts` to create slice. 
+
+```rust
+#[no_mangle]
+pub unsafe extern "C" fn csharp_to_rust_string(utf16_str: *const u16, utf16_len: i32) {
+    let slice = std::slice::from_raw_parts(utf16_str, utf16_len as usize);
+    let str = String::from_utf16(slice).unwrap();
+    println!("{}", str);
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn csharp_to_rust_utf8(utf8_str: *const u8, utf8_len: i32) {
+    let slice = std::slice::from_raw_parts(utf8_str, utf8_len as usize);
+    let str = String::from_utf8_unchecked(slice.to_vec());
+    println!("{}", str);
+}
+
+
+#[no_mangle]
+pub unsafe extern "C" fn csharp_to_rust_bytes(bytes: *const u8, len: i32) {
+    let slice = std::slice::from_raw_parts(bytes, len as usize);
+    let vec = slice.to_vec();
+    println!("{:?}", vec);
+}
+```
+
+```csharp
+var str = "foobarbaz:あいうえお"; // JPN(Unicode)
+fixed (char* p = str)
+{
+    NativeMethods.csharp_to_rust_string((ushort*)p, str.Length);
+}
+
+var str2 = Encoding.UTF8.GetBytes("あいうえお:foobarbaz");
+fixed (byte* p = str2)
+{
+    NativeMethods.csharp_to_rust_utf8(p, str2.Length);
+}
+
+var bytes = new byte[] { 1, 10, 100, 255 };
+fixed (byte* p = bytes)
+{
+    NativeMethods.csharp_to_rust_bytes(p, bytes.Length);
+}
+```
+
+Again, the important thing is that memory allocated in Rust must release in Rust and memory allocated in C# must release in C#.
 
 Build Tracing
 ---

csbindgen-tests/build.rs

@@ -61,10 +61,10 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     csbindgen::Builder::default()
         .input_extern_file("src/lib.rs")
-        .csharp_class_name("LibRust")
+        .csharp_class_name("NativeMethods")
         .csharp_dll_name("csbindgen_tests")
         .csharp_use_function_pointer(true)
-        .generate_csharp_file("../dotnet-sandbox/method_call.cs")
+        .generate_csharp_file("../dotnet-sandbox/NativeMethods.cs")
         .unwrap();
 
     // csbindgen::Builder::new()

csbindgen-tests/src/lib.rs

@@ -25,7 +25,6 @@ mod lz4_ffi;
 // #[allow(non_camel_case_types)]
 // mod bullet3_ffi;
 
-
 // #[allow(dead_code)]
 // #[allow(non_snake_case)]
 // #[allow(non_camel_case_types)]
@@ -37,7 +36,6 @@ mod lz4_ffi;
 // #[allow(non_camel_case_types)]
 // mod quiche_ffi;
 
-
 // #[allow(dead_code)]
 // #[allow(non_snake_case)]
 // #[allow(non_camel_case_types)]
@@ -49,10 +47,6 @@ mod lz4_ffi;
 // #[allow(non_camel_case_types)]
 // mod zstd_ffi;
 
-
-
-
-
 #[allow(non_camel_case_types)]
 pub type LONG_PTR = ::std::os::raw::c_longlong;
 #[allow(non_camel_case_types)]
@@ -73,6 +67,33 @@ pub unsafe extern "C" fn nullpointer_test(p: *const u8) {
     };
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn csharp_to_rust_string(utf16_str: *const u16, utf16_len: i32) {
+    let slice = std::slice::from_raw_parts(utf16_str, utf16_len as usize);
+
+    let str = String::from_utf16(slice).unwrap();
+
+    println!("{}", str);
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn csharp_to_rust_utf8(utf8_str: *const u8, utf8_len: i32) {
+    let slice = std::slice::from_raw_parts(utf8_str, utf8_len as usize);
+    let str = String::from_utf8_unchecked(slice.to_vec());
+    println!("{}", str);
+}
+
+
+#[no_mangle]
+pub unsafe extern "C" fn csharp_to_rust_bytes(bytes: *const u8, len: i32) {
+    let slice = std::slice::from_raw_parts(bytes, len as usize);
+    let vec = slice.to_vec();
+    println!("{:?}", vec);
+}
+
+
+
+
 #[no_mangle]
 pub extern "C" fn callback_test(cb: extern "C" fn(a: i32) -> i32) -> i32 {
     cb(100)
@@ -85,7 +106,7 @@ pub extern "C" fn csharp_to_rust(cb: extern "C" fn(x: i32, y: i32) -> i32) {
 }
 
 #[no_mangle]
-pub extern "C" fn rust_to_csharp() -> extern fn(x: i32, y: i32) -> i32 {
+pub extern "C" fn rust_to_csharp() -> extern "C" fn(x: i32, y: i32) -> i32 {
     sum // return rust method
 }
 

csbindgen/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "csbindgen"
-version = "1.0.0"
+version = "1.1.0"
 edition = "2021"
 authors = [
   "Yoshifumi Kawai <ils@neue.cc>",

dotnet-sandbox/NativeMethods.cs

@@ -8,7 +8,7 @@ using System.Runtime.InteropServices;
 
 namespace CsBindgen
 {
-    internal static unsafe partial class LibRust
+    internal static unsafe partial class NativeMethods
     {
         const string __DllName = "csbindgen_tests";
 
@@ -21,6 +21,15 @@ namespace CsBindgen
         [DllImport(__DllName, EntryPoint = "nullpointer_test", CallingConvention = CallingConvention.Cdecl)]
         public static extern void nullpointer_test(byte* p);
 
+        [DllImport(__DllName, EntryPoint = "csharp_to_rust_string", CallingConvention = CallingConvention.Cdecl)]
+        public static extern void csharp_to_rust_string(ushort* utf16_str, int utf16_len);
+
+        [DllImport(__DllName, EntryPoint = "csharp_to_rust_utf8", CallingConvention = CallingConvention.Cdecl)]
+        public static extern void csharp_to_rust_utf8(byte* utf8_str, int utf8_len);
+
+        [DllImport(__DllName, EntryPoint = "csharp_to_rust_bytes", CallingConvention = CallingConvention.Cdecl)]
+        public static extern void csharp_to_rust_bytes(byte* bytes, int len);
+
         [DllImport(__DllName, EntryPoint = "callback_test", CallingConvention = CallingConvention.Cdecl)]
         public static extern int callback_test(delegate* unmanaged[Cdecl]<int, int> cb);
 

dotnet-sandbox/Program.cs

@@ -14,9 +14,33 @@ using System.Text;
 unsafe
 {
 
-    LibRust.call_bindgen_lz4();
 
-    LibRust.alias_test1(null);
+
+    //NativeMethods.call_bindgen_lz4();
+
+
+    var str = "foobarbaz:あいうえお"; // JPN(Unicode)
+    fixed (char* p = str)
+    {
+        NativeMethods.csharp_to_rust_string((ushort*)p, str.Length);
+    }
+
+    var str2 = Encoding.UTF8.GetBytes("あいうえお:foobarbaz");
+    fixed (byte* p = str2)
+    {
+        NativeMethods.csharp_to_rust_utf8(p, str2.Length);
+    }
+
+    var bytes = new byte[] { 1, 10, 100, 255 };
+    fixed (byte* p = bytes)
+    {
+        NativeMethods.csharp_to_rust_bytes(p, bytes.Length);
+    }
+
+
+
+    //NativeMethods.csharp_to_rust_utf8
+    //NativeMethods.alias_test1(null);
 
 
 
@@ -25,10 +49,10 @@ unsafe
     [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvCdecl) })]
     static int Sum(int x, int y) => x + y;
 
-    LibRust.csharp_to_rust(&Sum);
+    NativeMethods.csharp_to_rust(&Sum);
 
     // Rust -> C#, get typed delegate*
-    var f = LibRust.rust_to_csharp();
+    var f = NativeMethods.rust_to_csharp();
 
     var v = f(20, 30);
     Console.WriteLine(v); // 50
@@ -50,18 +74,18 @@ unsafe
     //Console.WriteLine(cc);
 
 
-        var context = LibRust.create_context();
+    //    var context = LibRust.create_context();
 
-        // do anything...
+    //    // do anything...
 
-        LibRust.delete_context(context);
+    //    LibRust.delete_context(context);
 
-    var ctx = LibRust.create_counter_context(); // ctx = void*
+    //var ctx = LibRust.create_counter_context(); // ctx = void*
 
-    LibRust.insert_counter_context(ctx, 10);
+    //LibRust.insert_counter_context(ctx, 10);
-    LibRust.insert_counter_context(ctx, 20);
+    //LibRust.insert_counter_context(ctx, 20);
 
-    LibRust.delete_counter_context(ctx);
+    //LibRust.delete_counter_context(ctx);
 
     //LibRust.insert_counter_context(ctx, 20);
     //LibRust.insert_counter_context(ctx, 30);