Added stackmap<> container

diff --git a/kernel/utils.h b/kernel/utils.h
index 4226e270e6585ea51fdff9f69c875624efe67375..7f10619bc98086180b0c0b3293b8c7899736e3fe 100644 (file)
--- a/kernel/utils.h
+++ b/kernel/utils.h
@@ -17,8 +17,114 @@
  *
  */
 
-#ifndef TOPOSORT_H
-#define TOPOSORT_H
+// This file contains various c++ utility routines and helper classes that
+// do not depend on any other components of yosys (except stuff like log_*).
+
+#include "kernel/yosys.h"
+
+#ifndef UTILS_H
+#define UTILS_H
+
+// ------------------------------------------------
+// A map-like container, but you can save and restore the state
+// ------------------------------------------------
+
+template<typename Key, typename T, typename Compare = std::less<Key>>
+struct stackmap
+{
+private:
+       std::vector<std::map<Key, T*, Compare>> backup_state;
+       std::map<Key, T, Compare> current_state;
+       static T empty_tuple;
+
+public:
+       stackmap() { }
+       stackmap(const std::map<Key, T, Compare> &other) : current_state(other) { }
+
+       template<typename Other>
+       void operator=(const Other &other)
+       {
+               for (auto &it : current_state)
+                       if (!backup_state.empty() && backup_state.back().count(it.first) == 0)
+                               backup_state.back()[it.first] = new T(it.second);
+               current_state.clear();
+
+               for (auto &it : other)
+                       set(it.first, it.second);
+       }
+
+       bool has(const Key &k)
+       {
+               return current_state.count(k) != 0;
+       }
+
+       void set(const Key &k, const T &v)
+       {
+               if (!backup_state.empty() && backup_state.back().count(k) == 0)
+                       backup_state.back()[k] = current_state.count(k) ? new T(current_state.at(k)) : nullptr;
+               current_state[k] = v;
+       }
+
+       void unset(const Key &k)
+       {
+               if (!backup_state.empty() && backup_state.back().count(k) == 0)
+                       backup_state.back()[k] = current_state.count(k) ? new T(current_state.at(k)) : nullptr;
+               current_state.erase(k);
+       }
+
+       const T &get(const Key &k)
+       {
+               if (current_state.count(k) == 0)
+                       return empty_tuple;
+               return current_state.at(k);
+       }
+
+       void reset(const Key &k)
+       {
+               for (int i = SIZE(backup_state)-1; i >= 0; i--)
+                       if (backup_state[i].count(k) != 0) {
+                               if (backup_state[i].at(k) == nullptr)
+                                       current_state.erase(k);
+                               else
+                                       current_state[k] = *backup_state[i].at(k);
+                               return;
+                       }
+               current_state.erase(k);
+       }
+
+       const std::map<Key, T, Compare> &stdmap()
+       {
+               return current_state;
+       }
+
+       void save()
+       {
+               backup_state.resize(backup_state.size()+1);
+       }
+
+       void restore()
+       {
+               log_assert(!backup_state.empty());
+               for (auto &it : backup_state.back())
+                       if (it.second != nullptr) {
+                               current_state[it.first] = *it.second;
+                               delete it.second;
+                       } else
+                               current_state.erase(it.first);
+               backup_state.pop_back();
+       }
+
+       ~stackmap()
+       {
+               while (!backup_state.empty())
+                       restore();
+       }
+};
+
+
+// ------------------------------------------------
+// A simple class for topological sorting
+// ------------------------------------------------
 
 template<typename T>
 struct TopoSort

diff --git a/kernel/yosys.h b/kernel/yosys.h
index e12069b4c7ad85ad7244fa0160bdb8a7d5cb7aa9..79c90628c929c6836f2d4837d5fc96a056b9eb67 100644 (file)
--- a/kernel/yosys.h
+++ b/kernel/yosys.h
@@ -42,6 +42,7 @@
 #include <vector>
 #include <string>
 #include <algorithm>
+#include <functional>
 #include <initializer_list>
 
 #include <stdarg.h>