[pushed] c++: constexpr returning deallocated ptr
Commit Message
In constexpr-new3.C, the f7 function returns a deleted pointer, which we
were happily caching because the new and delete are balanced. Don't.
Tested x86_64-pc-linux-gnu, applying to trunk.
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_call_expression): Check for
heap vars in the result.
---
gcc/cp/constexpr.cc | 5 +++++
1 file changed, 5 insertions(+)
base-commit: 1189c03859cefef4fc4fd44d57eb3d4d3348b562
prerequisite-patch-id: cc6e608c68f4eb133f6a153f83dfe4f033544cbd
@@ -1356,6 +1356,7 @@ static tree cxx_eval_constant_expression (const constexpr_ctx *, tree,
value_cat, bool *, bool *, tree * = NULL);
static tree cxx_fold_indirect_ref (const constexpr_ctx *, location_t, tree, tree,
bool * = NULL);
+static tree find_heap_var_refs (tree *, int *, void *);
/* Attempt to evaluate T which represents a call to a builtin function.
We assume here that all builtin functions evaluate to scalar types
@@ -2965,6 +2966,10 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
cacheable = false;
break;
}
+ /* Also don't cache a call that returns a deallocated pointer. */
+ if (cacheable && (cp_walk_tree_without_duplicates
+ (&result, find_heap_var_refs, NULL)))
+ cacheable = false;
}
/* Rewrite all occurrences of the function's RESULT_DECL with the