Source/cmDefinitions.h

   1 /*=========================================================================
   2
   3   Program:   CMake - Cross-Platform Makefile Generator
   4   Module:    $RCSfile: cmDefinitions.h,v $
   5   Language:  C++
   6   Date:      $Date: 2009-07-22 18:22:45 $
   7   Version:   $Revision: 1.1 $
   8
   9   Copyright (c) 2002 Kitware, Inc., Insight Consortium.  All rights reserved.
  10   See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
  11
  12      This software is distributed WITHOUT ANY WARRANTY; without even
  13      the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  14      PURPOSE.  See the above copyright notices for more information.
  15
  16 =========================================================================*/
  17 #ifndef cmDefinitions_h
  18 #define cmDefinitions_h
  19
  20 #include "cmStandardIncludes.h"
  21
  22 /** \class cmDefinitions
  23  * \brief Store a scope of variable definitions for CMake language.
  24  *
  25  * This stores the state of variable definitions (set or unset) for
  26  * one scope.  Sets are always local.  Gets search parent scopes
  27  * transitively and save results locally.
  28  */
  29 class cmDefinitions
  30 {
  31 public:
  32   /** Construct with the given parent scope.  */
  33   cmDefinitions(cmDefinitions* parent = 0);
  34
  35   /** Reset object as if newly constructed.  */
  36   void Reset(cmDefinitions* parent = 0);
  37
  38   /** Returns the parent scope, if any.  */
  39   cmDefinitions* GetParent() const { return this->Up; }
  40
  41   /** Get the value associated with a key; null if none.
  42       Store the result locally if it came from a parent.  */
  43   const char* Get(const char* key);
  44
  45   /** Set (or unset if null) a value associated with a key.  */
  46   const char* Set(const char* key, const char* value);
  47
  48   /** Compute the closure of all defined keys with values.
  49       This flattens the scope.  The result has no parent.  */
  50   cmDefinitions Closure() const;
  51
  52   /** Compute the set of all defined keys.  */
  53   std::set<cmStdString> ClosureKeys() const;
  54
  55 private:
  56   // String with existence boolean.
  57   struct Def: public cmStdString
  58   {
  59     Def(): cmStdString(), Exists(false) {}
  60     Def(const char* v): cmStdString(v?v:""), Exists(v?true:false) {}
  61     Def(Def const& d): cmStdString(d), Exists(d.Exists) {}
  62     bool Exists;
  63   };
  64   static Def NoDef;
  65
  66   // Parent scope, if any.
  67   cmDefinitions* Up;
  68
  69   // Local definitions, set or unset.
  70   typedef std::map<cmStdString, Def> MapType;
  71   MapType Map;
  72
  73   // Internal query and update methods.
  74   Def const& GetInternal(const char* key);
  75   Def const& SetInternal(const char* key, Def const& def);
  76
  77   // Implementation of Closure() method.
  78   struct ClosureTag {};
  79   cmDefinitions(ClosureTag const&, cmDefinitions const* root);
  80   void ClosureImpl(std::set<cmStdString>& undefined,
  81                    cmDefinitions const* defs);
  82
  83   // Implementation of ClosureKeys() method.
  84   void ClosureKeys(std::set<cmStdString>& defined,
  85                    std::set<cmStdString>& undefined) const;
  86 };
  87
  88 #endif