ENH: Add variable watch command

Source/cmCommands.cxx

@@ -52,6 +52,8 @@
 #include "cmUseMangledMesaCommand.cxx"
 #include "cmUtilitySourceCommand.cxx"
 #include "cmVariableRequiresCommand.cxx"
+#include "cmVariableWatchCommand.cxx"
+
 #include "cmWhileCommand.cxx"
 #include "cmWriteFileCommand.cxx"
 
@@ -105,6 +107,7 @@ void GetPredefinedCommands(std::list<cmCommand*>&
   commands.push_back(new cmUseMangledMesaCommand);
   commands.push_back(new cmUtilitySourceCommand);
   commands.push_back(new cmVariableRequiresCommand);
+  commands.push_back(new cmVariableWatchCommand);
   commands.push_back(new cmWhileCommand);
   commands.push_back(new cmWriteFileCommand);
 #endif

Source/cmFindPackageCommand.cxx

@@ -22,8 +22,10 @@
 #endif
 
 void cmFindPackageNeedBackwardsCompatibility(const std::string& variable,
-                                             int access_type, void* )
+  int access_type, void*, const char* newValue,
+  const cmMakefile*)
 {
+  (void)newValue;
 #ifdef CMAKE_BUILD_WITH_CMAKE
   if(access_type == cmVariableWatch::UNKNOWN_VARIABLE_READ_ACCESS)
     {

Source/cmMakefile.cxx

@@ -1215,7 +1215,9 @@ void cmMakefile::AddDefinition(const char* name, const char* value)
   if ( vv )
     {
     vv->VariableAccessed(this->TemporaryDefinitionKey, 
-                         cmVariableWatch::VARIABLE_MODIFIED_ACCESS);
+                         cmVariableWatch::VARIABLE_MODIFIED_ACCESS,
+                         value,
+                         this);
     }
 #endif
 }
@@ -1275,7 +1277,8 @@ void cmMakefile::AddDefinition(const char* name, bool value)
   cmVariableWatch* vv = this->GetVariableWatch();
   if ( vv )
     {
-    vv->VariableAccessed(name, cmVariableWatch::VARIABLE_MODIFIED_ACCESS);
+    vv->VariableAccessed(name, cmVariableWatch::VARIABLE_MODIFIED_ACCESS,
+      value?"ON":"OFF", this);
     }
 #endif
 }
@@ -1304,7 +1307,8 @@ void cmMakefile::RemoveDefinition(const char* name)
   cmVariableWatch* vv = this->GetVariableWatch();
   if ( vv )
     {
-    vv->VariableAccessed(name, cmVariableWatch::VARIABLE_REMOVED_ACCESS);
+    vv->VariableAccessed(name, cmVariableWatch::VARIABLE_REMOVED_ACCESS,
+      0, this);
     }
 #endif
 }
@@ -1649,7 +1653,8 @@ const char* cmMakefile::GetDefinition(const char* name) const
     {
     if ( def )
       {
-      vv->VariableAccessed(name, cmVariableWatch::VARIABLE_READ_ACCESS);
+      vv->VariableAccessed(name, cmVariableWatch::VARIABLE_READ_ACCESS,
+        def, this);
       }
     else 
       {
@@ -1659,13 +1664,13 @@ const char* cmMakefile::GetDefinition(const char* name) const
       if (pos2 != this->Definitions.end() && 
           cmSystemTools::IsOn((*pos2).second.c_str())) 
         {
-        vv->VariableAccessed
+        vv->VariableAccessed(name,
-          (name, cmVariableWatch::ALLOWED_UNKNOWN_VARIABLE_READ_ACCESS);
+          cmVariableWatch::ALLOWED_UNKNOWN_VARIABLE_READ_ACCESS, def, this);
         }
       else
         {
-        vv->VariableAccessed(name, cmVariableWatch::
+        vv->VariableAccessed(name,
-                             UNKNOWN_VARIABLE_READ_ACCESS);
+          cmVariableWatch::UNKNOWN_VARIABLE_READ_ACCESS, def, this);
         }
       }
     }

Source/cmVariableWatch.cxx

@@ -16,6 +16,25 @@
 =========================================================================*/
 #include "cmVariableWatch.h"
 
+static const char* const cmVariableWatchAccessStrings[] =
+{
+    "READ_ACCESS",
+    "UNKNOWN_READ_ACCESS",
+    "ALLOWED_UNKNOWN_READ_ACCESS",
+    "MODIFIED_ACCESS",
+    "REMOVED_ACCESS",
+    "NO_ACCESS"
+};
+
+const char* cmVariableWatch::GetAccessAsString(int access_type)
+{
+  if ( access_type < 0 || access_type >= cmVariableWatch::NO_ACCESS )
+    {
+    return "NO_ACCESS";
+    }
+  return cmVariableWatchAccessStrings[access_type];
+}
+
 cmVariableWatch::cmVariableWatch()
 {
 }
@@ -60,7 +79,9 @@ void cmVariableWatch::RemoveWatch(const std::string& variable,
 }
 
 void  cmVariableWatch::VariableAccessed(const std::string& variable, 
-                                        int access_type) const
+                                        int access_type,
+                                        const char* newValue,
+                                        const cmMakefile* mf) const
 {
   cmVariableWatch::StringToVectorOfPairs::const_iterator mit = 
     this->WatchMap.find(variable);
@@ -70,7 +91,8 @@ void  cmVariableWatch::VariableAccessed(const std::string& variable,
     cmVariableWatch::VectorOfPairs::const_iterator it;
     for ( it = vp->begin(); it != vp->end(); it ++ )
       {
-      it->Method(variable, access_type, it->ClientData);
+      it->Method(variable, access_type, it->ClientData,
+        newValue, mf);
       }
     }
 }

Source/cmVariableWatch.h

@@ -19,6 +19,8 @@
 
 #include "cmStandardIncludes.h"
 
+class cmMakefile;
+
 /** \class cmVariableWatch
  * \brief Helper class for watching of variable accesses.
  *
@@ -28,7 +30,7 @@ class cmVariableWatch
 {
 public:
   typedef void (*WatchMethod)(const std::string& variable, int access_type,
-                              void* client_data);
+    void* client_data, const char* newValue, const cmMakefile* mf);
 
   cmVariableWatch();
   ~cmVariableWatch();
@@ -43,14 +45,15 @@ public:
   /**
    * This method is called when variable is accessed
    */
-  void VariableAccessed(const std::string& variable, int access_type) const;
+  void VariableAccessed(const std::string& variable, int access_type,
+    const char* newValue, const cmMakefile* mf) const;
 
   /**
    * Different access types.
    */
   enum
     {
-      VARIABLE_READ_ACCESS,
+    VARIABLE_READ_ACCESS = 0,
     UNKNOWN_VARIABLE_READ_ACCESS,
     ALLOWED_UNKNOWN_VARIABLE_READ_ACCESS,
     VARIABLE_MODIFIED_ACCESS,
@@ -58,6 +61,11 @@ public:
     NO_ACCESS
     };
 
+  /**
+   * Return the access as string
+   */
+  static const char* GetAccessAsString(int access_type);
+  
 protected:
   struct Pair
   {

Source/cmVariableWatchCommand.cxx

@@ -0,0 +1,136 @@
+/*=========================================================================
+
+  Program:   CMake - Cross-Platform Makefile Generator
+  Module:    $RCSfile$
+  Language:  C++
+  Date:      $Date$
+  Version:   $Revision$
+
+  Copyright (c) 2002 Kitware, Inc., Insight Consortium.  All rights reserved.
+  See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even 
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
+     PURPOSE.  See the above copyright notices for more information.
+
+=========================================================================*/
+#include "cmVariableWatchCommand.h"
+
+#include "cmVariableWatch.h"
+
+//----------------------------------------------------------------------------
+static void cmVariableWatchCommandVariableAccessed(
+  const std::string& variable, int access_type, void* client_data,
+  const char* newValue, const cmMakefile* mf)
+{
+  cmVariableWatchCommand* command = static_cast<cmVariableWatchCommand*>(client_data);
+  command->VariableAccessed(variable, access_type, newValue, mf);
+}
+
+//----------------------------------------------------------------------------
+cmVariableWatchCommand::cmVariableWatchCommand()
+{
+  this->InCallback = false;
+}
+
+//----------------------------------------------------------------------------
+bool cmVariableWatchCommand::InitialPass(std::vector<std::string> const& args)
+{
+  if ( args.size() < 1 )
+    {
+    this->SetError("must be called with at least one argument.");
+    return false;
+    }
+  std::string variable = args[0];
+  if ( args.size() > 1 )
+    {
+    std::string command = args[1];
+    this->Handlers[variable].Commands.push_back(args[1]);
+    }
+  if ( variable == "CMAKE_CURRENT_LIST_FILE" )
+    {
+    cmOStringStream ostr;
+    ostr << "cannot be set on the variable: " << variable.c_str();
+    this->SetError(ostr.str().c_str());
+    return false;
+    }
+
+  this->Makefile->GetCMakeInstance()->GetVariableWatch()->AddWatch(
+    variable, cmVariableWatchCommandVariableAccessed, this);
+
+  return true;
+}
+
+//----------------------------------------------------------------------------
+void cmVariableWatchCommand::VariableAccessed(const std::string& variable,
+  int access_type, const char* newValue, const cmMakefile* mf)
+{
+  if ( this->InCallback )
+    {
+    return;
+    }
+  this->InCallback = true;
+
+  cmListFileFunction newLFF;
+  cmVariableWatchCommandHandler *handler = &this->Handlers[variable];
+  cmVariableWatchCommandHandler::VectorOfCommands::iterator it;
+  cmListFileArgument arg;
+  bool processed = false;
+  const char* accessString = cmVariableWatch::GetAccessAsString(access_type);
+  const char* currentListFile = mf->GetDefinition("CMAKE_CURRENT_LIST_FILE");
+
+  /// Ultra bad!!
+  cmMakefile* makefile = const_cast<cmMakefile*>(mf);
+
+  std::string stack = makefile->GetProperty("LISTFILE_STACK");
+  for ( it = handler->Commands.begin(); it != handler->Commands.end();
+    ++ it )
+    {
+    std::string command = *it;
+    newLFF.Arguments.clear();
+    newLFF.Arguments.push_back(cmListFileArgument(variable, true, "unknown", 9999));
+    newLFF.Arguments.push_back(cmListFileArgument(accessString, true, "unknown", 9999));
+    newLFF.Arguments.push_back(cmListFileArgument(newValue?newValue:"", true, "unknown", 9999));
+    newLFF.Arguments.push_back(cmListFileArgument(currentListFile, true, "unknown", 9999));
+    newLFF.Arguments.push_back(cmListFileArgument(stack, true, "unknown", 9999));
+    newLFF.Name = command; 
+    newLFF.FilePath = "Some weird path";
+    newLFF.Line = 9999;
+    if(!makefile->ExecuteCommand(newLFF))
+      {
+      arg.FilePath =  "Unknown";
+      arg.Line = 0;
+      cmOStringStream error;
+      error << "Error in cmake code at\n"
+        << arg.FilePath << ":" << arg.Line << ":\n"
+        << "A command failed during the invocation of callback\""
+        << command << "\".";
+      cmSystemTools::Error(error.str().c_str());
+      this->InCallback = false;
+      return;
+      }
+    processed = true;
+    }
+  if ( !processed )
+    {
+    cmOStringStream msg;
+    msg << "* Variable \"" << variable.c_str() << "\" was accessed using "
+      << accessString << " in: " << currentListFile << std::endl;
+    msg << "  The value of the variable: \"" << newValue << "\"" << std::endl;
+    msg << "  The list file stack: " << stack.c_str();
+    cmSystemTools::Message(msg.str().c_str());
+    std::vector<std::string> vars = makefile->GetDefinitions();
+    cmOStringStream msg2;
+    size_t cc;
+    for ( cc = 0; cc < vars.size(); cc ++ )
+      {
+      if ( vars[cc] == variable )
+        {
+        continue;
+        }
+      msg2 << vars[cc] << " = \"" << makefile->GetDefinition(vars[cc].c_str()) << "\"" << std::endl;
+      }
+    //cmSystemTools::Message(msg2.str().c_str());
+    }
+  this->InCallback = false;
+}

Source/cmVariableWatchCommand.h

@@ -0,0 +1,98 @@
+/*=========================================================================
+
+  Program:   CMake - Cross-Platform Makefile Generator
+  Module:    $RCSfile$
+  Language:  C++
+  Date:      $Date$
+  Version:   $Revision$
+
+  Copyright (c) 2002 Kitware, Inc., Insight Consortium.  All rights reserved.
+  See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even 
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
+     PURPOSE.  See the above copyright notices for more information.
+
+=========================================================================*/
+#ifndef cmVariableWatchCommand_h
+#define cmVariableWatchCommand_h
+
+#include "cmCommand.h"
+
+class cmVariableWatchCommandHandler
+{
+public:
+  typedef std::vector<std::string> VectorOfCommands;
+  VectorOfCommands Commands;
+};
+
+/** \class cmVariableWatchCommand
+ * \brief Watch when the variable changes and invoke command
+ *
+ */
+class cmVariableWatchCommand : public cmCommand
+{
+public:
+  /**
+   * This is a virtual constructor for the command.
+   */
+  virtual cmCommand* Clone() 
+    {
+    return new cmVariableWatchCommand;
+    }
+
+  //! Default constructor
+  cmVariableWatchCommand();
+
+  /**
+   * This is called when the command is first encountered in
+   * the CMakeLists.txt file.
+   */
+  virtual bool InitialPass(std::vector<std::string> const& args);
+
+  /**
+   * This determines if the command is invoked when in script mode.
+   */
+  virtual bool IsScriptable() { return true; }
+
+  /**
+   * The name of the command as specified in CMakeList.txt.
+   */
+  virtual const char* GetName() { return "VARIABLE_WATCH";}
+
+  /**
+   * Succinct documentation.
+   */
+  virtual const char* GetTerseDocumentation() 
+    {
+    return "Watch the CMake variable for change.";
+    }
+  
+  /**
+   * More documentation.
+   */
+  virtual const char* GetFullDocumentation()
+    {
+    return
+      "  VARIABLE_WATCH(<variable name> [<command to execute>])\n"
+      "If the specified variable changes, the message will be printed about "
+      "the variable being changed. If the command is spceified, the command "
+      "will be executed. The command will receive the following arguments:"
+      " COMMAND(<variable> <access> <value> <current list file> <stack>)";
+    }
+  
+  cmTypeMacro(cmVariableWatchCommand, cmCommand);
+
+  void VariableAccessed(const std::string& variable, int access_type,
+    const char* newValue, const cmMakefile* mf);
+
+protected:
+  std::map<std::string, cmVariableWatchCommandHandler> Handlers;
+
+  bool InCallback;
+};
+
+
+#endif
+
+

Source/cmake.cxx

@@ -88,7 +88,7 @@
 #include <memory> // auto_ptr
 
 void cmNeedBackwardsCompatibility(const std::string& variable,
-                                  int access_type, void* )
+  int access_type, void*, const char*, const cmMakefile*)
 {
 #ifdef CMAKE_BUILD_WITH_CMAKE
   if (access_type == cmVariableWatch::UNKNOWN_VARIABLE_READ_ACCESS)

Tests/CMakeTests/CMakeLists.txt

@@ -4,7 +4,8 @@ SET(CMAKE_EXECUTABLE "${EXECUTABLE_OUTPUT_PATH}/cmake")
 MACRO(AddCMakeTest TestName Arguments)
   CONFIGURE_FILE("${CMAKE_CURRENT_SOURCE_DIR}/${TestName}Test.cmake.in"
     "${CMAKE_CURRENT_BINARY_DIR}/${TestName}Test.cmake" @ONLY IMMEDIATE)
-  ADD_TEST(CMake.List ${CMAKE_EXECUTABLE} -P "${CMAKE_CURRENT_BINARY_DIR}/ListTest.cmake" ${Arguments})
+  ADD_TEST(CMake.${TestName} ${CMAKE_EXECUTABLE} -P "${CMAKE_CURRENT_BINARY_DIR}/${TestName}Test.cmake" ${Arguments})
 ENDMACRO(AddCMakeTest)
 
 AddCMakeTest(List "")
+AddCMakeTest(VariableWatch "")

Tests/CMakeTests/VariableWatchTest.cmake.in

@@ -0,0 +1,22 @@
+MESSAGE("Start")
+
+VARIABLE_WATCH(TESTVAR MESSAGE)
+VARIABLE_WATCH(TESTVAR1)
+
+macro(testwatch var access file stack)
+  MESSAGE("There was a ${access} access done on the variable: ${var} in file ${file}")
+  MESSAGE("List file stack is: ${stack}")
+endmacro(testwatch)
+
+VARIABLE_WATCH(somevar testwatch)
+
+set(TESTVAR1 "1")
+set(TESTVAR "1")
+set(TESTVAR1 "0")
+set(TESTVAR "0")
+
+
+message("Variable: ${somevar}")
+set(somevar "1")
+message("Variable: ${somevar}")
+remove(somevar)