Rust binding for LLVM MC disassembler

Author: zznop

rust/src/llvm.rs

@@ -1,21 +1,33 @@
 use binaryninjacore_sys::BNLlvmServicesDisasmInstruction;
-use std::ffi::CStr;
+use std::ffi::{CStr, CString};
+use std::os::raw::{c_char, c_int};
 
 pub fn disas_instruction(triplet: &str, data: &[u8], address64: u64) -> Option<(usize, String)> {
     unsafe {
-        let mut buf = vec![0; 256];
+        let triplet = CString::new(triplet).ok()?;
+        let mut src = data.to_vec();
+        let mut buf = vec![0u8; 256];
         let instr_len = BNLlvmServicesDisasmInstruction(
-            triplet.as_ptr() as *const i8,
-            data.as_ptr() as *mut u8,
-            data.len() as i32,
+            triplet.as_ptr(),
+            src.as_mut_ptr(),
+            src.len() as c_int,
             address64,
-            buf.as_mut_ptr() as *mut i8,
+            buf.as_mut_ptr() as *mut c_char,
             buf.len(),
         );
+
         if instr_len > 0 {
-            let cstr = CStr::from_ptr(buf.as_ptr() as *const i8);
-            let string = cstr.to_str().unwrap().to_string();
-            Some((instr_len as usize, string))
+            // Convert buf (u8) → &CStr by finding the first NUL
+            if let Some(z) = buf.iter().position(|&b| b == 0) {
+                let s = CStr::from_bytes_with_nul(&buf[..=z])
+                    .unwrap()
+                    .to_string_lossy()
+                    .into_owned();
+                Some((instr_len as usize, s))
+            } else {
+                // Callee didn't NULL terminate, return an empty string
+                Some((instr_len as usize, String::new()))
+            }
         } else {
             None
         }