Add Ptr::from_int and Ptr::to_int (#229)

Author: lucic71

cpp2rust/converter/models/converter_refcount.cpp

@@ -1341,8 +1341,29 @@ bool ConverterRefCount::VisitExplicitCastExpr(clang::ExplicitCastExpr *expr) {
     return false;
   case clang::Stmt::CStyleCastExprClass:
   case clang::Stmt::CXXStaticCastExprClass:
+    if (expr->getCastKind() == clang::CastKind::CK_PointerToIntegral ||
+        expr->getCastKind() == clang::CastKind::CK_IntegralToPointer) {
+      std::string dst_type;
+      {
+        PushConversionKind push(*this, ConversionKind::Unboxed);
+        dst_type = ToString(expr->getType());
+      }
+      if (expr->getCastKind() == clang::CastKind::CK_PointerToIntegral) {
+        StrCat(std::format("{}.to_int()", ToString(expr->getSubExpr())));
+        computed_expr_type_ = ComputedExprType::FreshValue;
+      } else {
+        StrCat(std::format("<{}>::from_int({})", dst_type,
+                           ToString(expr->getSubExpr())));
+        computed_expr_type_ = ComputedExprType::FreshPointer;
+      }
+      return false;
+    }
+
     if (!VisitFunctionPointerCast(expr)) {
       return false;
+    } else if (expr->getSubExpr()->getType()->isVoidPointerType() &&
+               expr->getType()->isVoidPointerType()) {
+      return Convert(expr->getSubExpr());
     } else if (expr->getSubExpr()->getType()->isVoidPointerType() &&
                expr->getType()->isPointerType()) {
       Convert(expr->getSubExpr());

libcc2rs/src/rc.rs

@@ -1221,6 +1221,30 @@ impl<T: ?Sized> AsPointerDyn<T> for Rc<RefCell<T>> {
 impl<T: 'static> ByteRepr for Ptr<T> {}
 impl ByteRepr for AnyPtr {}
 
+impl<T: 'static> Ptr<T> {
+    pub fn to_int(&self) -> usize {
+        let mut buf = vec![0u8; Self::byte_size()];
+        self.to_bytes(&mut buf);
+        usize::from_bytes(&buf[..std::mem::size_of::<usize>()])
+    }
+
+    pub fn from_int(value: usize) -> Self {
+        let mut buf = vec![0u8; Self::byte_size()];
+        value.to_bytes(&mut buf[..std::mem::size_of::<usize>()]);
+        Self::from_bytes(&buf)
+    }
+}
+
+impl AnyPtr {
+    pub fn to_int(&self) -> usize {
+        self.reinterpret_cast::<u8>().to_int()
+    }
+
+    pub fn from_int(value: usize) -> Self {
+        Ptr::<u8>::from_int(value).to_any()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

tests/unit/out/refcount/unconst.rs

@@ -0,0 +1,24 @@
+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 main() {
+    std::process::exit(main_0());
+}
+fn main_0() -> i32 {
+    let a: Value<i32> = Rc::new(RefCell::new(1));
+    let p: Value<Ptr<i32>> = Rc::new(RefCell::new((a.as_pointer())));
+    let q: Value<Ptr<i32>> = Rc::new(RefCell::new(
+        (<AnyPtr>::from_int(((*p.borrow()).clone() as Ptr<i32>).to_any().to_int()))
+            .reinterpret_cast::<i32>(),
+    ));
+    assert!({
+        let _lhs = (*p.borrow()).clone();
+        _lhs == (*q.borrow()).clone()
+    });
+    return 0;
+}

tests/unit/out/unsafe/unconst.rs

@@ -0,0 +1,21 @@
+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 fn main() {
+    unsafe {
+        std::process::exit(main_0() as i32);
+    }
+}
+unsafe fn main_0() -> i32 {
+    let a: i32 = 1;
+    let mut p: *const i32 = (&a as *const i32);
+    let mut q: *mut i32 = (((((p) as *const i32 as *const ::libc::c_void) as u64)
+        as *mut ::libc::c_void) as *mut i32);
+    assert!(((p) == ((q).cast_const())));
+    return 0;
+}

tests/unit/unconst.cpp

@@ -0,0 +1,13 @@
+// panic: refcount
+#include <assert.h>
+#include <stdint.h>
+
+#define UNCONST(p) ((void *)(uintptr_t)(const void *)(p))
+
+int main() {
+  const int a = 1;
+  const int *p = &a;
+  auto q = static_cast<int *>(UNCONST(p));
+  assert(p == q);
+  return 0;
+}