cmState.cxx

/*============================================================================
  CMake - Cross Platform Makefile Generator
  Copyright 2015 Stephen Kelly <steveire@gmail.com>

  Distributed under the OSI-approved BSD License (the "License");
  see accompanying file Copyright.txt for details.

  This software is distributed WITHOUT ANY WARRANTY; without even the
  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the License for more information.
============================================================================*/
#include "cmState.h"

#include "cmAlgorithms.h"
#include "cmCacheManager.h"
#include "cmCommand.h"
#include "cmDefinitions.h"
#include "cmVersion.h"
#include "cmake.h"

#include <assert.h>

struct cmState::SnapshotDataType
{
  cmState::PositionType ScopeParent;
  cmState::PositionType DirectoryParent;
  cmLinkedTree<cmState::PolicyStackEntry>::iterator Policies;
  cmLinkedTree<cmState::PolicyStackEntry>::iterator PolicyRoot;
  cmLinkedTree<cmState::PolicyStackEntry>::iterator PolicyScope;
  cmState::SnapshotType SnapshotType;
  bool Keep;
  cmLinkedTree<std::string>::iterator ExecutionListFile;
  cmLinkedTree<cmState::BuildsystemDirectoryStateType>::iterator
    BuildSystemDirectory;
  cmLinkedTree<cmDefinitions>::iterator Vars;
  cmLinkedTree<cmDefinitions>::iterator Root;
  cmLinkedTree<cmDefinitions>::iterator Parent;
  std::vector<std::string>::size_type IncludeDirectoryPosition;
  std::vector<std::string>::size_type CompileDefinitionsPosition;
  std::vector<std::string>::size_type CompileOptionsPosition;
};

struct cmState::PolicyStackEntry : public cmPolicies::PolicyMap
{
  typedef cmPolicies::PolicyMap derived;
  PolicyStackEntry(bool w = false)
    : derived()
    , Weak(w)
  {
  }
  PolicyStackEntry(derived const& d, bool w)
    : derived(d)
    , Weak(w)
  {
  }
  PolicyStackEntry(PolicyStackEntry const& r)
    : derived(r)
    , Weak(r.Weak)
  {
  }
  bool Weak;
};

struct cmState::BuildsystemDirectoryStateType
{
  cmState::PositionType DirectoryEnd;

  std::string Location;
  std::string OutputLocation;

  std::vector<std::string> CurrentSourceDirectoryComponents;
  std::vector<std::string> CurrentBinaryDirectoryComponents;
  // The top-most directories for relative path conversion.  Both the
  // source and destination location of a relative path conversion
  // must be underneath one of these directories (both under source or
  // both under binary) in order for the relative path to be evaluated
  // safely by the build tools.
  std::string RelativePathTopSource;
  std::string RelativePathTopBinary;

  std::vector<std::string> IncludeDirectories;
  std::vector<cmListFileBacktrace> IncludeDirectoryBacktraces;

  std::vector<std::string> CompileDefinitions;
  std::vector<cmListFileBacktrace> CompileDefinitionsBacktraces;

  std::vector<std::string> CompileOptions;
  std::vector<cmListFileBacktrace> CompileOptionsBacktraces;

  std::string ProjectName;

  cmPropertyMap Properties;

  std::vector<cmState::Snapshot> Children;
};

cmState::cmState()
  : IsInTryCompile(false)
  , WindowsShell(false)
  , WindowsVSIDE(false)
  , WatcomWMake(false)
  , MinGWMake(false)
  , NMake(false)
  , MSYSShell(false)
{
  this->CacheManager = new cmCacheManager;
}

cmState::~cmState()
{
  delete this->CacheManager;
  cmDeleteAll(this->Commands);
}

const char* cmState::GetTargetTypeName(cmState::TargetType targetType)
{
  switch (targetType) {
    case cmState::STATIC_LIBRARY:
      return "STATIC_LIBRARY";
    case cmState::MODULE_LIBRARY:
      return "MODULE_LIBRARY";
    case cmState::SHARED_LIBRARY:
      return "SHARED_LIBRARY";
    case cmState::OBJECT_LIBRARY:
      return "OBJECT_LIBRARY";
    case cmState::EXECUTABLE:
      return "EXECUTABLE";
    case cmState::UTILITY:
      return "UTILITY";
    case cmState::GLOBAL_TARGET:
      return "GLOBAL_TARGET";
    case cmState::INTERFACE_LIBRARY:
      return "INTERFACE_LIBRARY";
    case cmState::UNKNOWN_LIBRARY:
      return "UNKNOWN_LIBRARY";
  }
  assert(0 && "Unexpected target type");
  return CM_NULLPTR;
}

const char* cmCacheEntryTypes[] = { "BOOL",          "PATH",     "FILEPATH",
                                    "STRING",        "INTERNAL", "STATIC",
                                    "UNINITIALIZED", CM_NULLPTR };

const char* cmState::CacheEntryTypeToString(cmState::CacheEntryType type)
{
  if (type > 6) {
    return cmCacheEntryTypes[6];
  }
  return cmCacheEntryTypes[type];
}

cmState::CacheEntryType cmState::StringToCacheEntryType(const char* s)
{
  int i = 0;
  while (cmCacheEntryTypes[i]) {
    if (strcmp(s, cmCacheEntryTypes[i]) == 0) {
      return static_cast<cmState::CacheEntryType>(i);
    }
    ++i;
  }
  return STRING;
}

bool cmState::IsCacheEntryType(std::string const& key)
{
  for (int i = 0; cmCacheEntryTypes[i]; ++i) {
    if (strcmp(key.c_str(), cmCacheEntryTypes[i]) == 0) {
      return true;
    }
  }
  return false;
}

bool cmState::LoadCache(const std::string& path, bool internal,
                        std::set<std::string>& excludes,
                        std::set<std::string>& includes)
{
  return this->CacheManager->LoadCache(path, internal, excludes, includes);
}

bool cmState::SaveCache(const std::string& path)
{
  return this->CacheManager->SaveCache(path);
}

bool cmState::DeleteCache(const std::string& path)
{
  return this->CacheManager->DeleteCache(path);
}

std::vector<std::string> cmState::GetCacheEntryKeys() const
{
  std::vector<std::string> definitions;
  definitions.reserve(this->CacheManager->GetSize());
  cmCacheManager::CacheIterator cit = this->CacheManager->GetCacheIterator();
  for (cit.Begin(); !cit.IsAtEnd(); cit.Next()) {
    definitions.push_back(cit.GetName());
  }
  return definitions;
}

const char* cmState::GetCacheEntryValue(std::string const& key) const
{
  cmCacheManager::CacheEntry* e = this->CacheManager->GetCacheEntry(key);
  if (!e) {
    return CM_NULLPTR;
  }
  return e->Value.c_str();
}

const char* cmState::GetInitializedCacheValue(std::string const& key) const
{
  return this->CacheManager->GetInitializedCacheValue(key);
}

cmState::CacheEntryType cmState::GetCacheEntryType(
  std::string const& key) const
{
  cmCacheManager::CacheIterator it =
    this->CacheManager->GetCacheIterator(key.c_str());
  return it.GetType();
}

void cmState::SetCacheEntryValue(std::string const& key,
                                 std::string const& value)
{
  this->CacheManager->SetCacheEntryValue(key, value);
}

void cmState::SetCacheEntryProperty(std::string const& key,
                                    std::string const& propertyName,
                                    std::string const& value)
{
  cmCacheManager::CacheIterator it =
    this->CacheManager->GetCacheIterator(key.c_str());
  it.SetProperty(propertyName, value.c_str());
}

void cmState::SetCacheEntryBoolProperty(std::string const& key,
                                        std::string const& propertyName,
                                        bool value)
{
  cmCacheManager::CacheIterator it =
    this->CacheManager->GetCacheIterator(key.c_str());
  it.SetProperty(propertyName, value);
}

std::vector<std::string> cmState::GetCacheEntryPropertyList(
  const std::string& key)
{
  cmCacheManager::CacheIterator it =
    this->CacheManager->GetCacheIterator(key.c_str());
  return it.GetPropertyList();
}

const char* cmState::GetCacheEntryProperty(std::string const& key,
                                           std::string const& propertyName)
{
  cmCacheManager::CacheIterator it =
    this->CacheManager->GetCacheIterator(key.c_str());
  if (!it.PropertyExists(propertyName)) {
    return CM_NULLPTR;
  }
  return it.GetProperty(propertyName);
}

bool cmState::GetCacheEntryPropertyAsBool(std::string const& key,
                                          std::string const& propertyName)
{
  return this->CacheManager->GetCacheIterator(key.c_str())
    .GetPropertyAsBool(propertyName);
}

void cmState::AddCacheEntry(const std::string& key, const char* value,
                            const char* helpString,
                            cmState::CacheEntryType type)
{
  this->CacheManager->AddCacheEntry(key, value, helpString, type);
}

void cmState::RemoveCacheEntry(std::string const& key)
{
  this->CacheManager->RemoveCacheEntry(key);
}

void cmState::AppendCacheEntryProperty(const std::string& key,
                                       const std::string& property,
                                       const std::string& value, bool asString)
{
  this->CacheManager->GetCacheIterator(key.c_str())
    .AppendProperty(property, value.c_str(), asString);
}

void cmState::RemoveCacheEntryProperty(std::string const& key,
                                       std::string const& propertyName)
{
  this->CacheManager->GetCacheIterator(key.c_str())
    .SetProperty(propertyName, (void*)CM_NULLPTR);
}

cmState::Snapshot cmState::Reset()
{
  this->GlobalProperties.clear();
  this->PropertyDefinitions.clear();

  PositionType pos = this->SnapshotData.Truncate();
  this->ExecutionListFiles.Truncate();

  {
    cmLinkedTree<BuildsystemDirectoryStateType>::iterator it =
      this->BuildsystemDirectory.Truncate();
    it->IncludeDirectories.clear();
    it->IncludeDirectoryBacktraces.clear();
    it->CompileDefinitions.clear();
    it->CompileDefinitionsBacktraces.clear();
    it->CompileOptions.clear();
    it->CompileOptionsBacktraces.clear();
    it->DirectoryEnd = pos;
    it->Properties.clear();
    it->Children.clear();
  }

  this->PolicyStack.Clear();
  pos->Policies = this->PolicyStack.Root();
  pos->PolicyRoot = this->PolicyStack.Root();
  pos->PolicyScope = this->PolicyStack.Root();
  assert(pos->Policies.IsValid());
  assert(pos->PolicyRoot.IsValid());

  {
    std::string srcDir =
      cmDefinitions::Get("CMAKE_SOURCE_DIR", pos->Vars, pos->Root);
    std::string binDir =
      cmDefinitions::Get("CMAKE_BINARY_DIR", pos->Vars, pos->Root);
    this->VarTree.Clear();
    pos->Vars = this->VarTree.Push(this->VarTree.Root());
    pos->Parent = this->VarTree.Root();
    pos->Root = this->VarTree.Root();

    pos->Vars->Set("CMAKE_SOURCE_DIR", srcDir.c_str());
    pos->Vars->Set("CMAKE_BINARY_DIR", binDir.c_str());
  }

  this->DefineProperty("RULE_LAUNCH_COMPILE", cmProperty::DIRECTORY, "", "",
                       true);
  this->DefineProperty("RULE_LAUNCH_LINK", cmProperty::DIRECTORY, "", "",
                       true);
  this->DefineProperty("RULE_LAUNCH_CUSTOM", cmProperty::DIRECTORY, "", "",
                       true);

  this->DefineProperty("RULE_LAUNCH_COMPILE", cmProperty::TARGET, "", "",
                       true);
  this->DefineProperty("RULE_LAUNCH_LINK", cmProperty::TARGET, "", "", true);
  this->DefineProperty("RULE_LAUNCH_CUSTOM", cmProperty::TARGET, "", "", true);

  return Snapshot(this, pos);
}

void cmState::DefineProperty(const std::string& name,
                             cmProperty::ScopeType scope,
                             const char* ShortDescription,
                             const char* FullDescription, bool chained)
{
  this->PropertyDefinitions[scope].DefineProperty(
    name, scope, ShortDescription, FullDescription, chained);
}

cmPropertyDefinition const* cmState::GetPropertyDefinition(
  const std::string& name, cmProperty::ScopeType scope) const
{
  if (this->IsPropertyDefined(name, scope)) {
    cmPropertyDefinitionMap const& defs =
      this->PropertyDefinitions.find(scope)->second;
    return &defs.find(name)->second;
  }
  return CM_NULLPTR;
}

bool cmState::IsPropertyDefined(const std::string& name,
                                cmProperty::ScopeType scope) const
{
  std::map<cmProperty::ScopeType, cmPropertyDefinitionMap>::const_iterator it =
    this->PropertyDefinitions.find(scope);
  if (it == this->PropertyDefinitions.end()) {
    return false;
  }
  return it->second.IsPropertyDefined(name);
}

bool cmState::IsPropertyChained(const std::string& name,
                                cmProperty::ScopeType scope) const
{
  std::map<cmProperty::ScopeType, cmPropertyDefinitionMap>::const_iterator it =
    this->PropertyDefinitions.find(scope);
  if (it == this->PropertyDefinitions.end()) {
    return false;
  }
  return it->second.IsPropertyChained(name);
}

void cmState::SetLanguageEnabled(std::string const& l)
{
  std::vector<std::string>::iterator it = std::lower_bound(
    this->EnabledLanguages.begin(), this->EnabledLanguages.end(), l);
  if (it == this->EnabledLanguages.end() || *it != l) {
    this->EnabledLanguages.insert(it, l);
  }
}

bool cmState::GetLanguageEnabled(std::string const& l) const
{
  return std::binary_search(this->EnabledLanguages.begin(),
                            this->EnabledLanguages.end(), l);
}

std::vector<std::string> cmState::GetEnabledLanguages() const
{
  return this->EnabledLanguages;
}

void cmState::SetEnabledLanguages(std::vector<std::string> const& langs)
{
  this->EnabledLanguages = langs;
}

void cmState::ClearEnabledLanguages()
{
  this->EnabledLanguages.clear();
}

bool cmState::GetIsInTryCompile() const
{
  return this->IsInTryCompile;
}

void cmState::SetIsInTryCompile(bool b)
{
  this->IsInTryCompile = b;
}

void cmState::RenameCommand(std::string const& oldName,
                            std::string const& newName)
{
  // if the command already exists, free the old one
  std::string sOldName = cmSystemTools::LowerCase(oldName);
  std::string sNewName = cmSystemTools::LowerCase(newName);
  std::map<std::string, cmCommand*>::iterator pos =
    this->Commands.find(sOldName);
  if (pos == this->Commands.end()) {
    return;
  }
  cmCommand* cmd = pos->second;

  pos = this->Commands.find(sNewName);
  if (pos != this->Commands.end()) {
    delete pos->second;
    this->Commands.erase(pos);
  }
  this->Commands.insert(std::make_pair(sNewName, cmd));
  pos = this->Commands.find(sOldName);
  this->Commands.erase(pos);
}

void cmState::AddCommand(cmCommand* command)
{
  std::string name = cmSystemTools::LowerCase(command->GetName());
  // if the command already exists, free the old one
  std::map<std::string, cmCommand*>::iterator pos = this->Commands.find(name);
  if (pos != this->Commands.end()) {
    delete pos->second;
    this->Commands.erase(pos);
  }
  this->Commands.insert(std::make_pair(name, command));
}

void cmState::RemoveUnscriptableCommands()
{
  std::vector<std::string> unscriptableCommands;
  for (std::map<std::string, cmCommand*>::iterator pos =
         this->Commands.begin();
       pos != this->Commands.end();) {
    if (!pos->second->IsScriptable()) {
      delete pos->second;
      this->Commands.erase(pos++);
    } else {
      ++pos;
    }
  }
}

cmCommand* cmState::GetCommand(std::string const& name) const
{
  cmCommand* command = CM_NULLPTR;
  std::string sName = cmSystemTools::LowerCase(name);
  std::map<std::string, cmCommand*>::const_iterator pos =
    this->Commands.find(sName);
  if (pos != this->Commands.end()) {
    command = (*pos).second;
  }
  return command;
}

std::vector<std::string> cmState::GetCommandNames() const
{
  std::vector<std::string> commandNames;
  commandNames.reserve(this->Commands.size());
  std::map<std::string, cmCommand*>::const_iterator cmds =
    this->Commands.begin();
  for (; cmds != this->Commands.end(); ++cmds) {
    commandNames.push_back(cmds->first);
  }
  return commandNames;
}

void cmState::RemoveUserDefinedCommands()
{
  std::vector<cmCommand*> renamedCommands;
  for (std::map<std::string, cmCommand*>::iterator j = this->Commands.begin();
       j != this->Commands.end();) {
    if (j->second->IsA("cmMacroHelperCommand") ||
        j->second->IsA("cmFunctionHelperCommand")) {
      delete j->second;
      this->Commands.erase(j++);
    } else if (j->first != j->second->GetName()) {
      renamedCommands.push_back(j->second);
      this->Commands.erase(j++);
    } else {
      ++j;
    }
  }
  for (std::vector<cmCommand*>::const_iterator it = renamedCommands.begin();
       it != renamedCommands.end(); ++it) {
    this->Commands[cmSystemTools::LowerCase((*it)->GetName())] = *it;
  }
}

void cmState::SetGlobalProperty(const std::string& prop, const char* value)
{
  this->GlobalProperties.SetProperty(prop, value);
}

void cmState::AppendGlobalProperty(const std::string& prop, const char* value,
                                   bool asString)
{
  this->GlobalProperties.AppendProperty(prop, value, asString);
}

const char* cmState::GetGlobalProperty(const std::string& prop)
{
  if (prop == "CACHE_VARIABLES") {
    std::vector<std::string> cacheKeys = this->GetCacheEntryKeys();
    this->SetGlobalProperty("CACHE_VARIABLES", cmJoin(cacheKeys, ";").c_str());
  } else if (prop == "COMMANDS") {
    std::vector<std::string> commands = this->GetCommandNames();
    this->SetGlobalProperty("COMMANDS", cmJoin(commands, ";").c_str());
  } else if (prop == "IN_TRY_COMPILE") {
    this->SetGlobalProperty("IN_TRY_COMPILE",
                            this->IsInTryCompile ? "1" : "0");
  } else if (prop == "ENABLED_LANGUAGES") {
    std::string langs;
    langs = cmJoin(this->EnabledLanguages, ";");
    this->SetGlobalProperty("ENABLED_LANGUAGES", langs.c_str());
  }
#define STRING_LIST_ELEMENT(F) ";" #F
  if (prop == "CMAKE_C_KNOWN_FEATURES") {
    return FOR_EACH_C_FEATURE(STRING_LIST_ELEMENT) + 1;
  }
  if (prop == "CMAKE_CXX_KNOWN_FEATURES") {
    return FOR_EACH_CXX_FEATURE(STRING_LIST_ELEMENT) + 1;
  }
#undef STRING_LIST_ELEMENT
  return this->GlobalProperties.GetPropertyValue(prop);
}

bool cmState::GetGlobalPropertyAsBool(const std::string& prop)
{
  return cmSystemTools::IsOn(this->GetGlobalProperty(prop));
}

void cmState::SetSourceDirectory(std::string const& sourceDirectory)
{
  this->SourceDirectory = sourceDirectory;
  cmSystemTools::ConvertToUnixSlashes(this->SourceDirectory);

  cmSystemTools::SplitPath(
    cmSystemTools::CollapseFullPath(this->SourceDirectory),
    this->SourceDirectoryComponents);
}

const char* cmState::GetSourceDirectory() const
{
  return this->SourceDirectory.c_str();
}

std::vector<std::string> const& cmState::GetSourceDirectoryComponents() const
{
  return this->SourceDirectoryComponents;
}

void cmState::SetBinaryDirectory(std::string const& binaryDirectory)
{
  this->BinaryDirectory = binaryDirectory;
  cmSystemTools::ConvertToUnixSlashes(this->BinaryDirectory);

  cmSystemTools::SplitPath(
    cmSystemTools::CollapseFullPath(this->BinaryDirectory),
    this->BinaryDirectoryComponents);
}

void cmState::SetWindowsShell(bool windowsShell)
{
  this->WindowsShell = windowsShell;
}

bool cmState::UseWindowsShell() const
{
  return this->WindowsShell;
}

void cmState::SetWindowsVSIDE(bool windowsVSIDE)
{
  this->WindowsVSIDE = windowsVSIDE;
}

bool cmState::UseWindowsVSIDE() const
{
  return this->WindowsVSIDE;
}

void cmState::SetWatcomWMake(bool watcomWMake)
{
  this->WatcomWMake = watcomWMake;
}

bool cmState::UseWatcomWMake() const
{
  return this->WatcomWMake;
}

void cmState::SetMinGWMake(bool minGWMake)
{
  this->MinGWMake = minGWMake;
}

bool cmState::UseMinGWMake() const
{
  return this->MinGWMake;
}

void cmState::SetNMake(bool nMake)
{
  this->NMake = nMake;
}

bool cmState::UseNMake() const
{
  return this->NMake;
}

void cmState::SetMSYSShell(bool mSYSShell)
{
  this->MSYSShell = mSYSShell;
}

bool cmState::UseMSYSShell() const
{
  return this->MSYSShell;
}

unsigned int cmState::GetCacheMajorVersion() const
{
  return this->CacheManager->GetCacheMajorVersion();
}

unsigned int cmState::GetCacheMinorVersion() const
{
  return this->CacheManager->GetCacheMinorVersion();
}

const char* cmState::GetBinaryDirectory() const
{
  return this->BinaryDirectory.c_str();
}

std::vector<std::string> const& cmState::GetBinaryDirectoryComponents() const
{
  return this->BinaryDirectoryComponents;
}

void cmState::Directory::ComputeRelativePathTopSource()
{
  // Relative path conversion inside the source tree is not used to
  // construct relative paths passed to build tools so it is safe to use
  // even when the source is a network path.

  cmState::Snapshot snapshot = this->Snapshot_;
  std::vector<cmState::Snapshot> snapshots;
  snapshots.push_back(snapshot);
  while (true) {
    snapshot = snapshot.GetBuildsystemDirectoryParent();
    if (snapshot.IsValid()) {
      snapshots.push_back(snapshot);
    } else {
      break;
    }
  }

  std::string result = snapshots.front().GetDirectory().GetCurrentSource();

  for (std::vector<cmState::Snapshot>::const_iterator it =
         snapshots.begin() + 1;
       it != snapshots.end(); ++it) {
    std::string currentSource = it->GetDirectory().GetCurrentSource();
    if (cmSystemTools::IsSubDirectory(result, currentSource)) {
      result = currentSource;
    }
  }
  this->DirectoryState->RelativePathTopSource = result;
}

void cmState::Directory::ComputeRelativePathTopBinary()
{
  cmState::Snapshot snapshot = this->Snapshot_;
  std::vector<cmState::Snapshot> snapshots;
  snapshots.push_back(snapshot);
  while (true) {
    snapshot = snapshot.GetBuildsystemDirectoryParent();
    if (snapshot.IsValid()) {
      snapshots.push_back(snapshot);
    } else {
      break;
    }
  }

  std::string result = snapshots.front().GetDirectory().GetCurrentBinary();

  for (std::vector<cmState::Snapshot>::const_iterator it =
         snapshots.begin() + 1;
       it != snapshots.end(); ++it) {
    std::string currentBinary = it->GetDirectory().GetCurrentBinary();
    if (cmSystemTools::IsSubDirectory(result, currentBinary)) {
      result = currentBinary;
    }
  }

  // The current working directory on Windows cannot be a network
  // path.  Therefore relative paths cannot work when the binary tree
  // is a network path.
  if (result.size() < 2 || result.substr(0, 2) != "//") {
    this->DirectoryState->RelativePathTopBinary = result;
  } else {
    this->DirectoryState->RelativePathTopBinary = "";
  }
}

cmState::Snapshot cmState::CreateBaseSnapshot()
{
  PositionType pos = this->SnapshotData.Push(this->SnapshotData.Root());
  pos->DirectoryParent = this->SnapshotData.Root();
  pos->ScopeParent = this->SnapshotData.Root();
  pos->SnapshotType = BaseType;
  pos->Keep = true;
  pos->BuildSystemDirectory =
    this->BuildsystemDirectory.Push(this->BuildsystemDirectory.Root());
  pos->ExecutionListFile =
    this->ExecutionListFiles.Push(this->ExecutionListFiles.Root());
  pos->IncludeDirectoryPosition = 0;
  pos->CompileDefinitionsPosition = 0;
  pos->CompileOptionsPosition = 0;
  pos->BuildSystemDirectory->DirectoryEnd = pos;
  pos->Policies = this->PolicyStack.Root();
  pos->PolicyRoot = this->PolicyStack.Root();
  pos->PolicyScope = this->PolicyStack.Root();
  assert(pos->Policies.IsValid());
  assert(pos->PolicyRoot.IsValid());
  pos->Vars = this->VarTree.Push(this->VarTree.Root());
  assert(pos->Vars.IsValid());
  pos->Parent = this->VarTree.Root();
  pos->Root = this->VarTree.Root();
  return cmState::Snapshot(this, pos);
}

cmState::Snapshot cmState::CreateBuildsystemDirectorySnapshot(
  Snapshot originSnapshot)
{
  assert(originSnapshot.IsValid());
  PositionType pos = this->SnapshotData.Push(originSnapshot.Position);
  pos->DirectoryParent = originSnapshot.Position;
  pos->ScopeParent = originSnapshot.Position;
  pos->SnapshotType = BuildsystemDirectoryType;
  pos->Keep = true;
  pos->BuildSystemDirectory = this->BuildsystemDirectory.Push(
    originSnapshot.Position->BuildSystemDirectory);
  pos->ExecutionListFile =
    this->ExecutionListFiles.Push(originSnapshot.Position->ExecutionListFile);
  pos->BuildSystemDirectory->DirectoryEnd = pos;
  pos->Policies = originSnapshot.Position->Policies;
  pos->PolicyRoot = originSnapshot.Position->Policies;
  pos->PolicyScope = originSnapshot.Position->Policies;
  assert(pos->Policies.IsValid());
  assert(pos->PolicyRoot.IsValid());

  cmLinkedTree<cmDefinitions>::iterator origin = originSnapshot.Position->Vars;
  pos->Parent = origin;
  pos->Root = origin;
  pos->Vars = this->VarTree.Push(origin);

  cmState::Snapshot snapshot = cmState::Snapshot(this, pos);
  originSnapshot.Position->BuildSystemDirectory->Children.push_back(snapshot);
  snapshot.SetDefaultDefinitions();
  snapshot.InitializeFromParent();
  snapshot.SetDirectoryDefinitions();
  return snapshot;
}

cmState::Snapshot cmState::CreateFunctionCallSnapshot(
  cmState::Snapshot originSnapshot, std::string const& fileName)
{
  PositionType pos =
    this->SnapshotData.Push(originSnapshot.Position, *originSnapshot.Position);
  pos->ScopeParent = originSnapshot.Position;
  pos->SnapshotType = FunctionCallType;
  pos->Keep = false;
  pos->ExecutionListFile = this->ExecutionListFiles.Push(
    originSnapshot.Position->ExecutionListFile, fileName);
  pos->BuildSystemDirectory->DirectoryEnd = pos;
  pos->PolicyScope = originSnapshot.Position->Policies;
  assert(originSnapshot.Position->Vars.IsValid());
  cmLinkedTree<cmDefinitions>::iterator origin = originSnapshot.Position->Vars;
  pos->Parent = origin;
  pos->Vars = this->VarTree.Push(origin);
  return cmState::Snapshot(this, pos);
}

cmState::Snapshot cmState::CreateMacroCallSnapshot(
  cmState::Snapshot originSnapshot, std::string const& fileName)
{
  PositionType pos =
    this->SnapshotData.Push(originSnapshot.Position, *originSnapshot.Position);
  pos->SnapshotType = MacroCallType;
  pos->Keep = false;
  pos->ExecutionListFile = this->ExecutionListFiles.Push(
    originSnapshot.Position->ExecutionListFile, fileName);
  assert(originSnapshot.Position->Vars.IsValid());
  pos->BuildSystemDirectory->DirectoryEnd = pos;
  pos->PolicyScope = originSnapshot.Position->Policies;
  return cmState::Snapshot(this, pos);
}

cmState::Snapshot cmState::CreateIncludeFileSnapshot(
  cmState::Snapshot originSnapshot, const std::string& fileName)
{
  PositionType pos =
    this->SnapshotData.Push(originSnapshot.Position, *originSnapshot.Position);
  pos->SnapshotType = IncludeFileType;
  pos->Keep = true;
  pos->ExecutionListFile = this->ExecutionListFiles.Push(
    originSnapshot.Position->ExecutionListFile, fileName);
  assert(originSnapshot.Position->Vars.IsValid());
  pos->BuildSystemDirectory->DirectoryEnd = pos;
  pos->PolicyScope = originSnapshot.Position->Policies;
  return cmState::Snapshot(this, pos);
}

cmState::Snapshot cmState::CreateVariableScopeSnapshot(
  cmState::Snapshot originSnapshot)
{
  PositionType pos =
    this->SnapshotData.Push(originSnapshot.Position, *originSnapshot.Position);
  pos->ScopeParent = originSnapshot.Position;
  pos->SnapshotType = VariableScopeType;
  pos->Keep = false;
  pos->PolicyScope = originSnapshot.Position->Policies;
  assert(originSnapshot.Position->Vars.IsValid());

  cmLinkedTree<cmDefinitions>::iterator origin = originSnapshot.Position->Vars;
  pos->Parent = origin;
  pos->Vars = this->VarTree.Push(origin);
  assert(pos->Vars.IsValid());
  return cmState::Snapshot(this, pos);
}

cmState::Snapshot cmState::CreateInlineListFileSnapshot(
  cmState::Snapshot originSnapshot, const std::string& fileName)
{
  PositionType pos =
    this->SnapshotData.Push(originSnapshot.Position, *originSnapshot.Position);
  pos->SnapshotType = InlineListFileType;
  pos->Keep = true;
  pos->ExecutionListFile = this->ExecutionListFiles.Push(
    originSnapshot.Position->ExecutionListFile, fileName);
  pos->BuildSystemDirectory->DirectoryEnd = pos;
  pos->PolicyScope = originSnapshot.Position->Policies;
  return cmState::Snapshot(this, pos);
}

cmState::Snapshot cmState::CreatePolicyScopeSnapshot(
  cmState::Snapshot originSnapshot)
{
  PositionType pos =
    this->SnapshotData.Push(originSnapshot.Position, *originSnapshot.Position);
  pos->SnapshotType = PolicyScopeType;
  pos->Keep = false;
  pos->BuildSystemDirectory->DirectoryEnd = pos;
  pos->PolicyScope = originSnapshot.Position->Policies;
  return cmState::Snapshot(this, pos);
}

cmState::Snapshot cmState::Pop(cmState::Snapshot originSnapshot)
{
  PositionType pos = originSnapshot.Position;
  PositionType prevPos = pos;
  ++prevPos;
  prevPos->IncludeDirectoryPosition =
    prevPos->BuildSystemDirectory->IncludeDirectories.size();