Fix decomposition in loop

Author: lucic71

cpp2rust/converter/converter.cpp

@@ -1506,7 +1506,11 @@ bool Converter::VisitCXXForRangeStmt(clang::CXXForRangeStmt *stmt) {
   auto *begin =
       clang::cast<clang::VarDecl>(stmt->getBeginStmt()->getSingleDecl());
   auto *end = clang::cast<clang::VarDecl>(stmt->getEndStmt()->getSingleDecl());
-  begin->setDeclName(stmt->getLoopVariable()->getDeclName());
+  begin->setDeclName(
+      clang::isa<clang::DecompositionDecl>(stmt->getLoopVariable())
+          ? clang::DeclarationName(
+                &ctx_.Idents.get(GetNamedDeclAsString(stmt->getLoopVariable())))
+          : stmt->getLoopVariable()->getDeclName());
   StrCat("'loop_:");
   StrCat(keyword::kFor, GetNamedDeclAsString(begin), keyword::kIn,
          "IterRange::new(", ConvertFreshRValue(begin->getInit()), token::kComma,
@@ -2952,6 +2956,10 @@ bool Converter::IsReferenceType(const clang::Expr *expr) const {
            GetReturnTypeOfFunction(call)->isReferenceType();
   }
   if (const auto *decl_ref = clang::dyn_cast<clang::DeclRefExpr>(e)) {
+    if (auto *var = clang::dyn_cast<clang::VarDecl>(decl_ref->getDecl());
+        var && IsAliasOfInit(ctx_, var)) {
+      return IsReferenceType(var->getInit());
+    }
     return GetDeclRefType(curr_function_, decl_ref, decl_ref->getDecl())
         ->isReferenceType();
   }

tests/unit/out/refcount/structured_binding_range_for.rs

@@ -33,23 +33,35 @@ fn main_0() -> i32 {
             second: 6,
         },
     ])));
-    'loop_: for mut __decomp_0 in arr.as_pointer() as Ptr<Pair> {
+    'loop_: for __decomp_0 in IterRange::new(
+        (arr.as_pointer() as Ptr<Pair>),
+        (arr.as_pointer() as Ptr<Pair>).offset((3_i64) as isize),
+    ) {
+        let __decomp_0: Ptr<Pair> = (__decomp_0).clone();
         {
             let __rhs = __decomp_0.with(|__s| __s.second);
             field!(__decomp_0, first).with_mut(|__v| *__v = *__v + __rhs)
         };
     }
     assert!(({ (*arr.borrow())[(0) as usize].first } == 3));
     assert!(({ (*arr.borrow())[(2) as usize].first } == 11));
-    'loop_: for mut __decomp_1 in arr.as_pointer() as Ptr<Pair> {
-        let __decomp_1: Value<Pair> = Rc::new(RefCell::new(__decomp_1.upgrade().deref().clone()));
+    'loop_: for __decomp_1 in IterRange::new(
+        (arr.as_pointer() as Ptr<Pair>),
+        (arr.as_pointer() as Ptr<Pair>).offset((3_i64) as isize),
+    ) {
+        let __decomp_1: Value<Pair> =
+            Rc::new(RefCell::new((*__decomp_1.upgrade().deref()).clone()));
         (*__decomp_1.borrow_mut()).first = 0;
         (*__decomp_1.borrow_mut()).second = 0;
     }
     assert!(({ (*arr.borrow())[(1) as usize].first } == 7));
     assert!(({ (*arr.borrow())[(1) as usize].second } == 4));
     let mut sum: i32 = 0;
-    'loop_: for mut __decomp_2 in arr.as_pointer() as Ptr<Pair> {
+    'loop_: for __decomp_2 in IterRange::new(
+        (arr.as_pointer() as Ptr<Pair>),
+        (arr.as_pointer() as Ptr<Pair>).offset((3_i64) as isize),
+    ) {
+        let __decomp_2: Ptr<Pair> = (__decomp_2).clone();
         sum += (__decomp_2.with(|__s| __s.first) * __decomp_2.with(|__s| __s.second));
     }
     assert!((sum == (((3 * 2) + (7 * 4)) + (11 * 6))));

tests/unit/out/unsafe/structured_binding_range_for.rs

@@ -33,22 +33,28 @@ unsafe fn main_0() -> i32 {
             second: 6,
         },
     ];
-    'loop_: for __decomp_0 in 0..(arr.len()) {
-        let mut __decomp_0 = arr.as_mut_ptr().add(__decomp_0);
+    'loop_: for __decomp_0 in
+        IterRange::new(arr.as_mut_ptr(), arr.as_mut_ptr().offset((3_i64) as isize))
+    {
+        let __decomp_0: *mut Pair = &mut (*__decomp_0);
         (*__decomp_0).first += (*__decomp_0).second;
     }
     assert!(((arr[(0) as usize].first) == (3)));
     assert!(((arr[(2) as usize].first) == (11)));
-    'loop_: for __decomp_1 in 0..(arr.len()) {
-        let mut __decomp_1 = arr[__decomp_1].clone();
+    'loop_: for __decomp_1 in
+        IterRange::new(arr.as_mut_ptr(), arr.as_mut_ptr().offset((3_i64) as isize))
+    {
+        let mut __decomp_1: Pair = (*__decomp_1);
         __decomp_1.first = 0;
         __decomp_1.second = 0;
     }
     assert!(((arr[(1) as usize].first) == (7)));
     assert!(((arr[(1) as usize].second) == (4)));
     let mut sum: i32 = 0;
-    'loop_: for __decomp_2 in 0..(arr.len()) {
-        let mut __decomp_2 = arr.as_ptr().add(__decomp_2);
+    'loop_: for __decomp_2 in
+        IterRange::new(arr.as_mut_ptr(), arr.as_mut_ptr().offset((3_i64) as isize))
+    {
+        let __decomp_2: *const Pair = &(*__decomp_2);
         sum += (((*__decomp_2).first) * ((*__decomp_2).second));
     }
     assert!(((sum) == ((((3) * (2)) + ((7) * (4))) + ((11) * (6)))));