Merge pull request diffblue#223 from diffblue/feature/test-symbol_tablet

Updates to recording_symbol_tablet

Author: NathanJPhillips

cbmc/src/util/recording_symbol_table.h

@@ -20,12 +20,16 @@ class recording_symbol_tablet:public symbol_tablet
   typedef std::unordered_set<irep_idt, irep_id_hash> changesett;
 private:
   symbol_tablet &base_symbol_table;
+  // Symbols originally in the table will never be marked inserted
+  changesett inserted;
+  // get_writeable marks an existing symbol updated
+  // Inserted symbols are marked updated, removed ones aren't
   changesett updated;
+  // Symbols not originally in the table will never be marked removed
   changesett removed;
 
-public:
-  // NOLINTNEXTLINE(runtime/explicit) - No information is lost in conversion
-  recording_symbol_tablet(symbol_tablet &base_symbol_table)
+private:
+  explicit recording_symbol_tablet(symbol_tablet &base_symbol_table)
     : symbol_tablet(
         base_symbol_table.symbols,
         base_symbol_table.symbol_base_map,
@@ -34,6 +38,7 @@ class recording_symbol_tablet:public symbol_tablet
   {
   }
 
+public:
   recording_symbol_tablet(const recording_symbol_tablet &other)
     : symbol_tablet(
         other.base_symbol_table.symbols,
@@ -43,6 +48,11 @@ class recording_symbol_tablet:public symbol_tablet
   {
   }
 
+  static recording_symbol_tablet wrap(symbol_tablet &base_symbol_table)
+  {
+    return recording_symbol_tablet(base_symbol_table);
+  }
+
   virtual opt_symbol_reft get_writeable(const irep_idt &identifier) override
   {
     opt_symbol_reft result=base_symbol_table.get_writeable(identifier);
@@ -56,7 +66,7 @@ class recording_symbol_tablet:public symbol_tablet
     std::pair<symbolt &, bool> result=
       base_symbol_table.insert(std::move(symbol));
     if(result.second)
-      on_update(result.first.name);
+      on_insert(result.first.name);
     return result;
   }
 
@@ -73,19 +83,27 @@ class recording_symbol_tablet:public symbol_tablet
     base_symbol_table.clear();
   }
 
+  const changesett &get_inserted() const { return inserted; }
   const changesett &get_updated() const { return updated; }
   const changesett &get_removed() const { return removed; }
 
 private:
+  void on_insert(const irep_idt &id)
+  {
+    if(removed.erase(id)==0)
+      inserted.insert(id);
+    updated.insert(id);
+  }
+
   void on_update(const irep_idt &id)
   {
     updated.insert(id);
-    removed.erase(id);
   }
 
   void on_remove(const irep_idt &id)
   {
-    removed.insert(id);
+    if(inserted.erase(id)==0)
+      removed.insert(id);
     updated.erase(id);
   }
 };