scope.h

// Copyright (C) 2014, Daniel S. Fava
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
// copies of the Software, and to permit persons to whom the Software is 
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in 
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
#ifndef __SCOPE_H_
#define __SCOPE_H_
#include <list>
#include <map>
#include <llvm/IR/Value.h>
#include <llvm/IR/Type.h>

class SType {
public:
  llvm::Type* type;
  std::string sec;
  SType(llvm::Type* type, std::string sec) : type(type), sec(sec) { }
  SType() : type(NULL), sec("") { }
};

class Symbol {
public:
  llvm::Value* value;
  SType* stype;
  Symbol(llvm::Value* value, SType* stype) : value(value), stype(stype) { }
};

class SymbolTable {
private:
  std::string name;
  std::map<std::string, Symbol*> locals;

public:
  SymbolTable(std::string name) : name(name) { }
  ~SymbolTable() {
    for (std::map<std::string, Symbol*>::iterator it=locals.begin(); it != locals.end(); ++it) {
      delete it->second;
    }
  }
  void Insert(std::string name, Symbol* sym) { locals[name] = sym; }
  Symbol* LookUp(std::string name) {
    if (locals.find(name) == locals.end()) {
      return NULL;
    }
    return locals[name];
  }
};

class Scope {
private:
  std::list<SymbolTable*> scope;
  std::list<std::string> security_context;

public:
  Scope() { }
  int depth() { return scope.size(); }
  void InitializeScope(std::string name = "", std::string sec = "") {
    scope.push_front(new SymbolTable(name));
    security_context.push_front(sec);
  }
  void FinalizeScope() {
    SymbolTable* toDelete = scope.front();
    scope.pop_front();
    delete toDelete;
    security_context.pop_front();
  }
  void Insert(std::string name, Symbol* sym) { scope.front()->Insert(name, sym); }
  Symbol* LookUp(std::string name) {
    for (std::list<SymbolTable*>::iterator it=scope.begin(); it != scope.end(); ++it)
    {
      Symbol* sym = (*it)->LookUp(name);
      if (sym != NULL) return sym;
    }
    return NULL;
  }
  std::string getSecurityContext() {
    return security_context.front();
  }
};
#endif // __SCOPE_H_