bugfix: irep_hash_containert now keeps a copy of the contained ireps

Author: Daniel Kroening

src/util/irep_hash_container.cpp

@@ -21,13 +21,15 @@ size_t irep_hash_container_baset::number(const irept &irep)
   ptr_hasht::const_iterator it=ptr_hash.find(&irep.read());
 
   if(it!=ptr_hash.end())
-    return it->second;
+    return it->second.number;
 
   packedt packed;
   pack(irep, packed);
   size_t id=numbering.number(packed);
 
-  ptr_hash[&irep.read()]=id;
+  auto &irep_entry = ptr_hash[&irep.read()];
+  irep_entry.number = id;
+  irep_entry.irep = irep;
 
   return id;
 }

src/util/irep_hash_container.h

@@ -14,10 +14,9 @@ Author: Daniel Kroening, [email protected]
 
 #include <vector>
 
+#include "irep.h"
 #include "numbering.h"
 
-class irept;
-
 class irep_hash_container_baset
 {
 public:
@@ -46,7 +45,13 @@ class irep_hash_container_baset
     }
   };
 
-  typedef std::unordered_map<const void *, std::size_t, pointer_hasht>
+  struct irep_entryt
+  {
+    std::size_t number;
+    irept irep; // copy to keep addresses stable
+  };
+
+  typedef std::unordered_map<const void *, irep_entryt, pointer_hasht>
     ptr_hasht;
   ptr_hasht ptr_hash;