cmState: introduce methods for adding builtin commands

Source/cmState.cxx

@@ -12,10 +12,12 @@
 #include "cmCacheManager.h"
 #include "cmCommand.h"
 #include "cmDefinitions.h"
+#include "cmDisallowedCommand.h"
 #include "cmListFileCache.h"
 #include "cmStatePrivate.h"
 #include "cmStateSnapshot.h"
 #include "cmSystemTools.h"
+#include "cmUnexpectedCommand.h"
 #include "cmake.h"
 
 cmState::cmState()
@@ -410,6 +412,27 @@ void cmState::AddCommand(cmCommand* command)
   this->Commands.insert(std::make_pair(name, command));
 }
 
+void cmState::AddBuiltinCommand(std::string const& name, cmCommand* command)
+{
+  assert(name == cmSystemTools::LowerCase(name));
+  assert(name == cmSystemTools::LowerCase(command->GetName()));
+  assert(this->Commands.find(name) == this->Commands.end());
+  this->Commands.insert(std::make_pair(name, command));
+}
+
+void cmState::AddDisallowedCommand(std::string const& name, cmCommand* command,
+                                   cmPolicies::PolicyID policy,
+                                   const char* message)
+{
+  this->AddBuiltinCommand(name,
+                          new cmDisallowedCommand(command, policy, message));
+}
+
+void cmState::AddUnexpectedCommand(std::string const& name, const char* error)
+{
+  this->AddBuiltinCommand(name, new cmUnexpectedCommand(name, error));
+}
+
 cmCommand* cmState::GetCommand(std::string const& name) const
 {
   cmCommand* command = CM_NULLPTR;

Source/cmState.h

@@ -12,6 +12,7 @@
 
 #include "cmDefinitions.h"
 #include "cmLinkedTree.h"
+#include "cmPolicies.h"
 #include "cmProperty.h"
 #include "cmPropertyDefinitionMap.h"
 #include "cmPropertyMap.h"
@@ -121,6 +122,10 @@ public:
 
   cmCommand* GetCommand(std::string const& name) const;
   void AddCommand(cmCommand* command);
+  void AddBuiltinCommand(std::string const& name, cmCommand* command);
+  void AddDisallowedCommand(std::string const& name, cmCommand* command,
+                            cmPolicies::PolicyID policy, const char* message);
+  void AddUnexpectedCommand(std::string const& name, const char* error);
   void RenameCommand(std::string const& oldName, std::string const& newName);
   void RemoveUserDefinedCommands();
   std::vector<std::string> GetCommandNames() const;

bootstrap

@@ -278,6 +278,7 @@ CMAKE_CXX_SOURCES="\
   cmDefinitions \
   cmDepends \
   cmDependsC \
+  cmDisallowedCommand \
   cmDocumentationFormatter \
   cmEnableLanguageCommand \
   cmEnableTestingCommand \