Fix nullptr deref on HIR::Function

The clone interface on HIR::Functions can have an optional nullptr return
type which was always being derefed for the clone interface. This seems
to trigger when compiling with gcc-4.8 but not on modern GCC versions.

1 files changed, 13 insertions, 2 deletions

diff --git a/gcc/rust/hir/tree/rust-hir-item.h b/gcc/rust/hir/tree/rust-hir-item.h
index 109a5c2..1d45186 100644
--- a/gcc/rust/hir/tree/rust-hir-item.h
+++ b/gcc/rust/hir/tree/rust-hir-item.h
@@ -1111,11 +1111,16 @@ public:
     : VisItem (other), qualifiers (other.qualifiers),
       function_name (other.function_name),
       function_params (other.function_params),
-      return_type (other.return_type->clone_type ()),
       where_clause (other.where_clause),
       function_body (other.function_body->clone_block_expr ()),
       self (other.self), locus (other.locus)
   {
+    // guard to prevent null dereference (always required)
+    if (other.return_type != nullptr)
+      return_type = other.return_type->clone_type ();
+    else
+      return_type = nullptr;
+
     generic_params.reserve (other.generic_params.size ());
     for (const auto &e : other.generic_params)
       generic_params.push_back (e->clone_generic_param ());
@@ -1128,7 +1133,13 @@ public:
     function_name = other.function_name;
     qualifiers = other.qualifiers;
     function_params = other.function_params;
-    return_type = other.return_type->clone_type ();
+
+    // guard to prevent null dereference (always required)
+    if (other.return_type != nullptr)
+      return_type = other.return_type->clone_type ();
+    else
+      return_type = nullptr;
+
     where_clause = other.where_clause;
     function_body = other.function_body->clone_block_expr ();
     locus = other.locus;