Avoid depending on CMAKE_ROOT cache entry internally (#16015)

Use cmSystemTools::GetCMakeRoot() which always knows the location of our
resources.  Do not depend on CMAKE_ROOT because the user could unset it
from the cache.

Source/cmCreateTestSourceList.cxx

@@ -78,8 +78,7 @@ bool cmCreateTestSourceList
   driver += *i;
   ++i;
 
-  std::string configFile =
-    this->Makefile->GetRequiredDefinition("CMAKE_ROOT");
+  std::string configFile = cmSystemTools::GetCMakeRoot();
 
   configFile += "/Templates/TestDriver.cxx.in";
   // Create the test driver file

Source/cmExtraCodeBlocksGenerator.cxx

@@ -259,13 +259,12 @@ void cmExtraCodeBlocksGenerator
       }
 
     // Convert
-    const char* cmakeRoot = mf->GetDefinition("CMAKE_ROOT");
     for (std::vector<std::string>::const_iterator jt = listFiles.begin();
          jt != listFiles.end();
          ++jt)
       {
       // don't put cmake's own files into the project (#12110):
-      if (jt->find(cmakeRoot) == 0)
+      if (jt->find(cmSystemTools::GetCMakeRoot()) == 0)
         {
         continue;
         }

Source/cmGeneratorTarget.cxx

@@ -3909,8 +3909,7 @@ void checkPropertyConsistency(cmGeneratorTarget const* depender,
 
   std::vector<std::string> props;
   cmSystemTools::ExpandListArgument(prop, props);
-  std::string pdir =
-    dependee->Target->GetMakefile()->GetRequiredDefinition("CMAKE_ROOT");
+  std::string pdir = cmSystemTools::GetCMakeRoot();
   pdir += "/Help/prop_tgt/";
 
   for(std::vector<std::string>::iterator pi = props.begin();

Source/cmGlobalGenerator.cxx

@@ -820,7 +820,7 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
   // Now load files that can override any settings on the platform or for
   // the project First load the project compatibility file if it is in
   // cmake
-  std::string projectCompatibility = mf->GetDefinition("CMAKE_ROOT");
+  std::string projectCompatibility = cmSystemTools::GetCMakeRoot();
   projectCompatibility += "/Modules/";
   projectCompatibility += mf->GetSafeDefinition("PROJECT_NAME");
   projectCompatibility += "Compatibility.cmake";

Source/cmGlobalVisualStudioGenerator.cxx

@@ -184,12 +184,11 @@ void RegisterVisualStudioMacros(const std::string& macrosFile,
 //----------------------------------------------------------------------------
 void cmGlobalVisualStudioGenerator::ConfigureCMakeVisualStudioMacros()
 {
-  cmMakefile* mf = this->LocalGenerators[0]->GetMakefile();
   std::string dir = this->GetUserMacrosDirectory();
 
   if (dir != "")
     {
-    std::string src = mf->GetRequiredDefinition("CMAKE_ROOT");
+    std::string src = cmSystemTools::GetCMakeRoot();
     src += "/Templates/" CMAKE_VSMACROS_FILENAME;
 
     std::string dst = dir + "/CMakeMacros/" CMAKE_VSMACROS_FILENAME;

Source/cmMakefile.cxx

@@ -3738,17 +3738,13 @@ std::string cmMakefile::GetModulesFile(const char* filename) const
     }
 
   // Always search in the standard modules location.
-  const char* cmakeRoot = this->GetDefinition("CMAKE_ROOT");
-  if(cmakeRoot)
+  moduleInCMakeRoot = cmSystemTools::GetCMakeRoot();
+  moduleInCMakeRoot += "/Modules/";
+  moduleInCMakeRoot += filename;
+  cmSystemTools::ConvertToUnixSlashes(moduleInCMakeRoot);
+  if(!cmSystemTools::FileExists(moduleInCMakeRoot.c_str()))
     {
-    moduleInCMakeRoot = cmakeRoot;
-    moduleInCMakeRoot += "/Modules/";
-    moduleInCMakeRoot += filename;
-    cmSystemTools::ConvertToUnixSlashes(moduleInCMakeRoot);
-    if(!cmSystemTools::FileExists(moduleInCMakeRoot.c_str()))
-      {
-      moduleInCMakeRoot = "";
-      }
+    moduleInCMakeRoot = "";
     }
 
   // Normally, prefer the files found in CMAKE_MODULE_PATH. Only when the file
@@ -3763,7 +3759,7 @@ std::string cmMakefile::GetModulesFile(const char* filename) const
   if (!moduleInCMakeModulePath.empty() && !moduleInCMakeRoot.empty())
     {
     const char* currentFile = this->GetDefinition("CMAKE_CURRENT_LIST_FILE");
-    std::string mods = cmakeRoot + std::string("/Modules/");
+    std::string mods = cmSystemTools::GetCMakeRoot() + "/Modules/";
     if (currentFile && strncmp(currentFile, mods.c_str(), mods.size()) == 0)
       {
       switch (this->GetPolicyStatus(cmPolicies::CMP0017))

Source/cmQtAutoGeneratorInitializer.cxx

@@ -1003,8 +1003,7 @@ void cmQtAutoGeneratorInitializer::SetupAutoGenerateTarget(
     SetupAutoRccTarget(target);
     }
 
-  const char* cmakeRoot = makefile->GetSafeDefinition("CMAKE_ROOT");
-  std::string inputFile = cmakeRoot;
+  std::string inputFile = cmSystemTools::GetCMakeRoot();
   inputFile += "/Modules/AutogenInfo.cmake.in";
   std::string outputFile = targetDir;
   outputFile += "/AutogenInfo.cmake";

Source/cmake.cxx

@@ -2409,8 +2409,7 @@ int cmake::GetSystemInformation(std::vector<std::string>& args)
 
   // we have to find the module directory, so we can copy the files
   this->AddCMakePaths();
-  std::string modulesPath =
-    this->State->GetInitializedCacheValue("CMAKE_ROOT");
+  std::string modulesPath = cmSystemTools::GetCMakeRoot();
   modulesPath += "/Modules";
   std::string inFile = modulesPath;
   inFile += "/SystemInformation.cmake";