Add a strlcpy implementation

src/wrapper.rs

@@ -17,4 +17,5 @@
 //! Wrappers for different plugin types. Each wrapper has an entry point macro that you can pass the
 //! name of a type that implements `Plugin` to. The macro will handle the rest.
 
+pub mod util;
 pub mod vst3;

src/wrapper/util.rs

@@ -0,0 +1,35 @@
+// nih-plug: plugins, but rewritten in Rust
+// Copyright (C) 2022 Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+use std::cmp;
+use std::os::raw::c_char;
+
+/// The equivalent of the `strlcpy()` C function. Copy `src` to `dest` as a null-terminated
+/// C-string. If `dest` does not have enough capacity, add a null terminator at the end to prevent
+/// buffer overflows.
+pub fn strlcpy(dest: &mut [c_char], src: &str) {
+    if dest.is_empty() {
+        return;
+    }
+
+    let src_bytes: &[u8] = src.as_bytes();
+    let src_bytes_signed: &[i8] = unsafe { &*(src_bytes as *const [u8] as *const [i8]) };
+
+    // Make sure there's always room for a null terminator
+    let copy_len = cmp::min(dest.len() - 1, src.len());
+    dest[..copy_len].copy_from_slice(&src_bytes_signed[..copy_len]);
+    dest[copy_len] = 0;
+}