Default initialize object allocated with new (#390)

Author: lucic71

cpp2rust/converter/converter.cpp

@@ -3440,12 +3440,16 @@ bool Converter::VisitCXXNewExpr(clang::CXXNewExpr *expr) {
     if (!curr_init_type_.empty() && curr_init_type_.back()->isPointerType()) {
       StrCat(".as_mut_ptr()");
     }
+    SetFreshType(expr->getType());
   } else {
-    auto initializer_as_string = ToString(expr->getInitializer());
+    auto initializer_as_string =
+        expr->getInitializer() ? ToString(expr->getInitializer())
+                               : GetDefaultAsString(expr->getAllocatedType());
     auto new_as_string =
         std::format("(Box::leak(Box::new({})) as {})", initializer_as_string,
                     ToString(expr->getType()));
     StrCat(new_as_string);
+    SetFreshType(expr->getType());
   }
   return false;
 }

tests/unit/new.cpp

@@ -1,9 +1,24 @@
 #include <cassert>
 
+struct Pair {
+  int x, y;
+};
+
 int main() {
   int *x = new int(5);
   int out = *x;
   delete x;
   assert(out == 5);
+
+  int *y = new int;
+  *y = 9;
+  assert(*y == 9);
+  delete y;
+
+  Pair *p = new Pair;
+  p->x = 1;
+  p->y = 2;
+  assert(p->x + p->y == 3);
+  delete p;
   return 0;
 }

tests/unit/new_array.cpp

@@ -1,5 +1,22 @@
+static int sum(int *p, int n) {
+  int total = 0;
+  for (int i = 0; i < n; ++i) {
+    total += p[i];
+  }
+  return total;
+}
+
 int main() {
   int *array = new int[100];
   delete[] array;
+
+  int *filled = new int[4];
+  for (int i = 0; i < 4; ++i) {
+    filled[i] = i + 1;
+  }
+  if (sum(filled, 4) != 10) {
+    return 1;
+  }
+  delete[] filled;
   return 0;
 }

tests/unit/out/refcount/new.rs

@@ -6,6 +6,36 @@ use std::io::prelude::*;
 use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
+#[derive(Default)]
+pub struct Pair {
+    pub x: Value<i32>,
+    pub y: Value<i32>,
+}
+impl Clone for Pair {
+    fn clone(&self) -> Self {
+        let __this: Value<Pair> = Rc::new(RefCell::new(Self {
+            x: Rc::new(RefCell::new((*self.x.borrow()))),
+            y: Rc::new(RefCell::new((*self.y.borrow()))),
+        }));
+        let this: Ptr<Pair> = __this.as_pointer();
+        Rc::try_unwrap(__this).ok().unwrap().into_inner()
+    }
+}
+impl ByteRepr for Pair {
+    fn byte_size() -> usize {
+        8
+    }
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self.x.borrow()).to_bytes(&mut buf[0..4]);
+        (*self.y.borrow()).to_bytes(&mut buf[4..8]);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        Self {
+            x: Rc::new(RefCell::new(<i32>::from_bytes(&buf[0..4]))),
+            y: Rc::new(RefCell::new(<i32>::from_bytes(&buf[4..8]))),
+        }
+    }
+}
 pub fn main() {
     __cpp2rust_init_globals();
     std::process::exit(main_0());
@@ -15,6 +45,20 @@ fn main_0() -> i32 {
     let out: Value<i32> = Rc::new(RefCell::new(((*x.borrow()).read())));
     (*x.borrow()).delete();
     assert!(((*out.borrow()) == 5));
+    let y: Value<Ptr<i32>> = Rc::new(RefCell::new(Ptr::alloc(Default::default())));
+    (*y.borrow()).write(9);
+    assert!((((*y.borrow()).read()) == 9));
+    (*y.borrow()).delete();
+    let p: Value<Ptr<Pair>> = Rc::new(RefCell::new(Ptr::alloc(<Pair>::default())));
+    (*(*(*p.borrow()).upgrade().deref()).x.borrow_mut()) = 1;
+    (*(*(*p.borrow()).upgrade().deref()).y.borrow_mut()) = 2;
+    assert!(
+        ({
+            let _lhs = (*(*(*p.borrow()).upgrade().deref()).x.borrow());
+            _lhs + (*(*(*p.borrow()).upgrade().deref()).y.borrow())
+        } == 3)
+    );
+    (*p.borrow()).delete();
     return 0;
 }
 pub fn __cpp2rust_init_globals() {}

tests/unit/out/refcount/new_array.rs

@@ -6,6 +6,18 @@ use std::io::prelude::*;
 use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
+pub fn sum_0(p: Ptr<i32>, n: i32) -> i32 {
+    let p: Value<Ptr<i32>> = Rc::new(RefCell::new(p));
+    let n: Value<i32> = Rc::new(RefCell::new(n));
+    let total: Value<i32> = Rc::new(RefCell::new(0));
+    let i: Value<i32> = Rc::new(RefCell::new(0));
+    'loop_: while ((*i.borrow()) < (*n.borrow())) {
+        let __rhs = ((*p.borrow()).offset((*i.borrow()) as isize).read());
+        (*total.borrow_mut()) += __rhs;
+        (*i.borrow_mut()).prefix_inc();
+    }
+    return (*total.borrow());
+}
 pub fn main() {
     __cpp2rust_init_globals();
     std::process::exit(main_0());
@@ -17,6 +29,27 @@ fn main_0() -> i32 {
             .collect::<Box<[i32]>>(),
     )));
     (*array.borrow()).delete_array();
+    let filled: Value<Ptr<i32>> = Rc::new(RefCell::new(Ptr::alloc_array(
+        (0..4_usize)
+            .map(|_| <i32>::default())
+            .collect::<Box<[i32]>>(),
+    )));
+    let i: Value<i32> = Rc::new(RefCell::new(0));
+    'loop_: while ((*i.borrow()) < 4) {
+        let __rhs = ((*i.borrow()) + 1);
+        (*filled.borrow())
+            .offset((*i.borrow()) as isize)
+            .write(__rhs);
+        (*i.borrow_mut()).prefix_inc();
+    }
+    if (({
+        let _p: Ptr<i32> = (*filled.borrow()).clone();
+        sum_0(_p, 4)
+    }) != 10)
+    {
+        return 1;
+    }
+    (*filled.borrow()).delete_array();
     return 0;
 }
 pub fn __cpp2rust_init_globals() {}

tests/unit/out/unsafe/new.rs

@@ -6,6 +6,12 @@ use std::collections::BTreeMap;
 use std::io::{Read, Seek, Write};
 use std::os::fd::{AsFd, FromRawFd, IntoRawFd};
 use std::rc::Rc;
+#[repr(C)]
+#[derive(Copy, Clone, Default)]
+pub struct Pair {
+    pub x: i32,
+    pub y: i32,
+}
 pub fn main() {
     unsafe {
         __cpp2rust_init_globals();
@@ -17,6 +23,15 @@ unsafe fn main_0() -> i32 {
     let mut out: i32 = (*x);
     ::std::mem::drop(Box::from_raw(x));
     assert!(((out) == (5)));
+    let mut y: *mut i32 = (Box::leak(Box::new(0_i32)) as *mut i32);
+    (*y) = 9;
+    assert!(((*y) == (9)));
+    ::std::mem::drop(Box::from_raw(y));
+    let mut p: *mut Pair = (Box::leak(Box::new(<Pair>::default())) as *mut Pair);
+    (*p).x = 1;
+    (*p).y = 2;
+    assert!(((((*p).x) + ((*p).y)) == (3)));
+    ::std::mem::drop(Box::from_raw(p));
     return 0;
 }
 pub unsafe fn __cpp2rust_init_globals() {}

tests/unit/out/unsafe/new_array.rs

@@ -6,6 +6,15 @@ use std::collections::BTreeMap;
 use std::io::{Read, Seek, Write};
 use std::os::fd::{AsFd, FromRawFd, IntoRawFd};
 use std::rc::Rc;
+pub unsafe fn sum_0(mut p: *mut i32, mut n: i32) -> i32 {
+    let mut total: i32 = 0;
+    let mut i: i32 = 0;
+    'loop_: while ((i) < (n)) {
+        total += (*p.offset((i) as isize));
+        i.prefix_inc();
+    }
+    return total;
+}
 pub fn main() {
     unsafe {
         __cpp2rust_init_globals();
@@ -20,6 +29,24 @@ unsafe fn main_0() -> i32 {
         array,
         libcc2rs::malloc_usable_size(array as *mut ::libc::c_void) / ::std::mem::size_of::<i32>(),
     )));
+    let mut filled: *mut i32 =
+        Box::leak((0..4_usize).map(|_| 0_i32).collect::<Box<[i32]>>()).as_mut_ptr();
+    let mut i: i32 = 0;
+    'loop_: while ((i) < (4)) {
+        (*filled.offset((i) as isize)) = ((i) + (1));
+        i.prefix_inc();
+    }
+    if ((unsafe {
+        let _p: *mut i32 = filled;
+        sum_0(_p, 4)
+    }) != (10))
+    {
+        return 1;
+    }
+    ::std::mem::drop(Box::from_raw(::std::slice::from_raw_parts_mut(
+        filled,
+        libcc2rs::malloc_usable_size(filled as *mut ::libc::c_void) / ::std::mem::size_of::<i32>(),
+    )));
     return 0;
 }
 pub unsafe fn __cpp2rust_init_globals() {}