Add support for OTP 26 by supporting NIF v2.17 (#526)

This is adding support for the new functions that are included in the
latest OTP version 26.

Pre-release notes: https://github.com/erlang/otp/releases/tag/OTP-26.0-rc2

New functions added:
  - enif_set_option
  - enif_get_string_length
  - enif_make_new_atom
  - enif_make_new_atom_len

This version also introduce support for UTF8 atoms and strings in the
NIF interface.

rustler/build.rs

@@ -8,7 +8,7 @@ use std::env;
 use std::process::Command;
 
 // keep this sorted by version number
-const NIF_VERSION: &[&str] = &["2.14", "2.15", "2.16"];
+const NIF_VERSION: &[&str] = &["2.14", "2.15", "2.16", "2.17"];
 
 fn main() {
     let latest_version = NIF_VERSION.last().unwrap().to_string();

rustler_sys/build.rs

@@ -14,7 +14,7 @@ use std::process::Command;
 use std::{env, fs};
 
 const SNIPPET_NAME: &str = "nif_api.snippet";
-const SUPPORTED_VERSIONS: [(u32, u32); 3] = [(2, 14), (2, 15), (2, 16)];
+const SUPPORTED_VERSIONS: &[(u32, u32)] = &[(2, 14), (2, 15), (2, 16), (2, 17)];
 
 trait ApiBuilder {
     fn func(&mut self, ret: &str, name: &str, args: &str);
@@ -846,6 +846,7 @@ fn build_api(b: &mut dyn ApiBuilder, opts: &GenerateOptions) {
         b.func("c_int", "enif_make_map_from_arrays", "env: *mut ErlNifEnv, keys: *const ERL_NIF_TERM, values: *const ERL_NIF_TERM, cnt: usize, map_out: *mut ERL_NIF_TERM");
     }
 
+    // 2.15 was introduced in OTP 22
     if opts.nif_version >= (2, 15) {
         b.func(
             "ErlNifTermType",
@@ -862,10 +863,23 @@ fn build_api(b: &mut dyn ApiBuilder, opts: &GenerateOptions) {
         );
     }
 
+    // 2.16 was introduced in OTP 24
     if opts.nif_version >= (2, 16) {
         b.func("*const ErlNifResourceType", "enif_init_resource_type", "env: *mut ErlNifEnv, name_str: *const c_uchar, init: *const ErlNifResourceTypeInit, flags: ErlNifResourceFlags, tried: *mut ErlNifResourceFlags");
         b.func("c_int", "enif_dynamic_resource_call", "env: *mut ErlNifEnv, module: ERL_NIF_TERM, name: ERL_NIF_TERM, rsrc: ERL_NIF_TERM, call_data: *const c_void");
     }
+
+    // 2.17 was introduced in OTP 26
+    if opts.nif_version >= (2, 17) {
+        b.func(
+            "c_int",
+            "enif_set_option",
+            "env: *mut ErlNifEnv, opt: ErlNifOption",
+        );
+        b.func("c_int", "enif_get_string_length", "env: *mut ErlNifEnv, list: ERL_NIF_TERM, len: *mut c_uint, encoding: ErlNifCharEncoding");
+        b.func("c_int", "enif_make_new_atom", "env: *mut ErlNifEnv, name: *const c_uchar, atom: *mut ERL_NIF_TERM, encoding: ErlNifCharEncoding");
+        b.func("c_int", "enif_make_new_atom_len", "env: *mut ErlNifEnv, name: *const c_uchar, len: size_t, atom: *mut ERL_NIF_TERM, encoding: ErlNifCharEncoding");
+    }
 }
 
 fn parse_nif_version(version: &str) -> (u32, u32) {

rustler_sys/src/rustler_sys_api.rs

@@ -187,6 +187,7 @@ pub enum ErlNifResourceFlags {
 #[repr(C)]
 pub enum ErlNifCharEncoding {
     ERL_NIF_LATIN1 = 1,
+    ERL_NIF_UTF8 = 2,
 }
 
 /// See [ErlNifPid](http://www.erlang.org/doc/man/erl_nif.html#ErlNifPid) in the Erlang docs.
@@ -328,6 +329,15 @@ pub enum ErlNifTermType {
     ERL_NIF_TERM_TYPE__MISSING_DEFAULT_CASE__READ_THE_MANUAL = -1,
 }
 
+/// See [ErlNifOption](http://www.erlang.org/doc/man/erl_nif.html#ErlNifOption) in the Erlang docs.
+#[derive(Copy, Clone)]
+#[repr(C)]
+pub enum ErlNifOption {
+    // from https://github.com/erlang/otp/blob/1b3c6214d4bf359f7e5c143bef5c5ad9c90c5536/erts/emulator/beam/erl_nif.h#L333
+    ERL_NIF_OPT_DELAY_HALT = 1,
+    ERL_NIF_OPT_ON_HALT = 2,
+}
+
 // Include the file generated by `build.rs`.
 include!(concat!(env!("OUT_DIR"), "/nif_api.snippet"));
 // example of included content: