From 85234cb540c2b2863dfea6c20496dcb451df8889 Mon Sep 17 00:00:00 2001
From: Thomas Lively <7121787+tlively@users.noreply.github.com>
Date: Tue, 1 Sep 2020 15:55:58 -0700
Subject: Fix ExceptionPackage memory errors (#3088)

First, adds an explicit destructor call to fix a memory leak in
`Literal::operator=` in which existing `ExceptionPackage`s would be
silently dropped. Next, changes `Literal::getExceptionPackage` to
return the `ExceptionPackage` by value to avoid a use-after-free bug
in the interpreter that was surfaced by the new destructor call.

A future improvement would be to switch to using `std::variant`.

Fixes #3087.
---
 src/literal.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

(limited to 'src/literal.h')

diff --git a/src/literal.h b/src/literal.h
index 5c72bf96c..cffa9ab7d 100644
--- a/src/literal.h
+++ b/src/literal.h
@@ -135,10 +135,7 @@ public:
     assert(type == Type::funcref);
     return func;
   }
-  const ExceptionPackage& getExceptionPackage() const {
-    assert(type == Type::exnref);
-    return *exn.get();
-  }
+  ExceptionPackage getExceptionPackage() const;
 
   // careful!
   int32_t* geti32Ptr() {
-- 
cgit v1.2.3