From 73a154f7002b4cb9b8845337c271bac820241d9a Mon Sep 17 00:00:00 2001
From: Lucian Popescu <lucian.popescu@tecnico.ulisboa.pt>
Date: Mon, 6 Jul 2026 14:45:22 +0100
Subject: [PATCH] Add void pointer implicit conversion

---
 .../converter/models/converter_refcount.cpp   |  6 ++++
 .../refcount/void_ptr_implicit_conversion.rs  | 34 +++++++++++++++++++
 .../unsafe/void_ptr_implicit_conversion.rs    | 29 ++++++++++++++++
 tests/unit/void_ptr_implicit_conversion.c     | 19 +++++++++++
 4 files changed, 88 insertions(+)
 create mode 100644 tests/unit/out/refcount/void_ptr_implicit_conversion.rs
 create mode 100644 tests/unit/out/unsafe/void_ptr_implicit_conversion.rs
 create mode 100644 tests/unit/void_ptr_implicit_conversion.c

diff --git a/cpp2rust/converter/models/converter_refcount.cpp b/cpp2rust/converter/models/converter_refcount.cpp
index c7a2be2b..87d27035 100644
--- a/cpp2rust/converter/models/converter_refcount.cpp
+++ b/cpp2rust/converter/models/converter_refcount.cpp
@@ -1160,6 +1160,12 @@ bool ConverterRefCount::VisitImplicitCastExpr(clang::ImplicitCastExpr *expr) {
                            ToString(sub_expr->getType())));
       }
       computed_expr_type_ = ComputedExprType::FreshPointer;
+    } else if (sub_expr->getType()->isVoidPointerType() &&
+               expr->getType()->isPointerType()) {
+      Convert(sub_expr);
+      PushConversionKind push(*this, ConversionKind::Unboxed);
+      StrCat(std::format(".reinterpret_cast::<{}>()",
+                         ConvertPointeeType(expr->getType())));
     } else {
       Convert(sub_expr);
     }
diff --git a/tests/unit/out/refcount/void_ptr_implicit_conversion.rs b/tests/unit/out/refcount/void_ptr_implicit_conversion.rs
new file mode 100644
index 00000000..1ddcd67f
--- /dev/null
+++ b/tests/unit/out/refcount/void_ptr_implicit_conversion.rs
@@ -0,0 +1,34 @@
+extern crate libcc2rs;
+use libcc2rs::*;
+use std::cell::RefCell;
+use std::collections::BTreeMap;
+use std::io::prelude::*;
+use std::io::{Read, Seek, Write};
+use std::os::fd::AsFd;
+use std::rc::{Rc, Weak};
+pub fn bump_0(arg: AnyPtr) -> i32 {
+    let arg: Value<AnyPtr> = Rc::new(RefCell::new(arg));
+    let value: Value<Ptr<i32>> = Rc::new(RefCell::new(
+        ((*arg.borrow()).reinterpret_cast::<i32>()).clone(),
+    ));
+    {
+        let _ptr = (*value.borrow()).clone();
+        _ptr.write(_ptr.read() + 1)
+    };
+    return ((*value.borrow()).read());
+}
+pub fn main() {
+    std::process::exit(main_0());
+}
+fn main_0() -> i32 {
+    let value: Value<i32> = Rc::new(RefCell::new(41));
+    let opaque: Value<AnyPtr> = Rc::new(RefCell::new(((value.as_pointer()) as Ptr<i32>).to_any()));
+    let typed: Value<Ptr<i32>> = Rc::new(RefCell::new(
+        ((*opaque.borrow()).reinterpret_cast::<i32>()).clone(),
+    ));
+    assert!((((({ bump_0((*opaque.borrow()).clone(),) }) == 42) as i32) != 0));
+    assert!((((((*typed.borrow()).read()) == 42) as i32) != 0));
+    (*typed.borrow()).write(7);
+    assert!(((((*value.borrow()) == 7) as i32) != 0));
+    return 0;
+}
diff --git a/tests/unit/out/unsafe/void_ptr_implicit_conversion.rs b/tests/unit/out/unsafe/void_ptr_implicit_conversion.rs
new file mode 100644
index 00000000..57fadd9c
--- /dev/null
+++ b/tests/unit/out/unsafe/void_ptr_implicit_conversion.rs
@@ -0,0 +1,29 @@
+extern crate libc;
+use libc::*;
+extern crate libcc2rs;
+use libcc2rs::*;
+use std::collections::BTreeMap;
+use std::io::{Read, Seek, Write};
+use std::os::fd::{AsFd, FromRawFd, IntoRawFd};
+use std::rc::Rc;
+pub unsafe fn bump_0(mut arg: *mut ::libc::c_void) -> i32 {
+    let mut value: *mut i32 = (arg as *mut i32);
+    (*value) += 1;
+    return (*value);
+}
+pub fn main() {
+    unsafe {
+        std::process::exit(main_0() as i32);
+    }
+}
+unsafe fn main_0() -> i32 {
+    let mut value: i32 = 41;
+    let mut opaque: *mut ::libc::c_void =
+        ((&mut value as *mut i32) as *mut i32 as *mut ::libc::c_void);
+    let mut typed: *mut i32 = (opaque as *mut i32);
+    assert!(((((unsafe { bump_0(opaque,) }) == (42)) as i32) != 0));
+    assert!(((((*typed) == (42)) as i32) != 0));
+    (*typed) = 7;
+    assert!(((((value) == (7)) as i32) != 0));
+    return 0;
+}
diff --git a/tests/unit/void_ptr_implicit_conversion.c b/tests/unit/void_ptr_implicit_conversion.c
new file mode 100644
index 00000000..2f5c8edd
--- /dev/null
+++ b/tests/unit/void_ptr_implicit_conversion.c
@@ -0,0 +1,19 @@
+#include <assert.h>
+#include <stdint.h>
+
+static int32_t bump(void *arg) {
+  int32_t *value = arg;
+  *value += 1;
+  return *value;
+}
+
+int main() {
+  int32_t value = 41;
+  void *opaque = &value;
+  int32_t *typed = opaque;
+  assert(bump(opaque) == 42);
+  assert(*typed == 42);
+  *typed = 7;
+  assert(value == 7);
+  return 0;
+}