rospack.cpp

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/*
 * Copyright (C) 2008, Willow Garage, Inc., Morgan Quigley
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the names of Stanford University or Willow Garage, Inc. nor the names of its
 *     contributors may be used to endorse or promote products derived from
 *     this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <Python.h>
#include "rospack/rospack.h"
#include "utils.h"
#include "tinyxml2.h"

#include <boost/algorithm/string.hpp>
#include <boost/filesystem.hpp>
#include <boost/functional/hash.hpp>
#include <stdexcept>

#if defined(WIN32)
  #include <windows.h>
  #include <direct.h>
  #include <fcntl.h>  // for O_RDWR, O_EXCL, O_CREAT
  // simple workaround - could have issues though. See
  //   http://stackoverflow.com/questions/2915672/snprintf-and-visual-studio-2010
  // for potentially better solutions. Similar probably applies for some of the others
  #define snprintf _snprintf
  #define pclose _pclose
  #define popen _popen
  #define PATH_MAX MAX_PATH
  #if defined(__MINGW32__)
    #include <libgen.h> // for dirname
  #endif
  #if defined(_MSC_VER)
    #include <io.h> // _mktemp_s
  #endif
#else 
  #include <sys/types.h>
  #include <libgen.h>
  #include <pwd.h>
  #include <unistd.h>
  #include <sys/time.h>
#endif

#include <algorithm>
#include <climits>

#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <errno.h>

/* re-define some String functions for python 2.x */
#if PY_VERSION_HEX < 0x03000000
#undef PyBytes_AsString
#undef PyUnicode_AsUTF8
#undef PyUnicode_FromString
#define PyBytes_AsString PyString_AsString
#define PyUnicode_AsUTF8 PyString_AsString
#define PyUnicode_FromString PyString_FromString
#endif

// TODO:
//   recrawl on:
//     package not found in cache
//     package found in cache, but no manifest.xml present in filesystem

namespace fs = boost::filesystem;

namespace rospack
{
static const char* MANIFEST_TAG_PACKAGE = "package";
static const char* MANIFEST_TAG_STACK = "stack";
static const char* ROSPACK_MANIFEST_NAME = "manifest.xml";
static const char* ROSPACKAGE_MANIFEST_NAME = "package.xml";
static const char* ROSSTACK_MANIFEST_NAME = "stack.xml";
static const char* ROSPACK_CACHE_PREFIX = "rospack_cache";
static const char* ROSSTACK_CACHE_PREFIX = "rosstack_cache";
static const char* ROSPACK_NOSUBDIRS = "rospack_nosubdirs";
static const char* CATKIN_IGNORE = "CATKIN_IGNORE";
static const char* DOTROS_NAME = ".ros";
static const char* MSG_GEN_GENERATED_DIR = "msg_gen";
static const char* MSG_GEN_GENERATED_FILE = "generated";
static const char* SRV_GEN_GENERATED_DIR = "srv_gen";
static const char* SRV_GEN_GENERATED_FILE = "generated";
static const char* MANIFEST_TAG_ROSDEP = "rosdep";
static const char* MANIFEST_TAG_VERSIONCONTROL = "versioncontrol";
static const char* MANIFEST_TAG_EXPORT = "export";
static const char* MANIFEST_ATTR_NAME = "name";
static const char* MANIFEST_ATTR_TYPE = "type";
static const char* MANIFEST_ATTR_URL = "url";
static const char* MANIFEST_PREFIX = "${prefix}";
static const int MAX_CRAWL_DEPTH = 1000;
static const int MAX_DEPENDENCY_DEPTH = 1000;
static const double DEFAULT_MAX_CACHE_AGE = 60.0;

tinyxml2::XMLElement* get_manifest_root(Stackage* stackage);
double time_since_epoch();

#ifdef __APPLE__
  static const std::string g_ros_os = "osx";
#else
  #if defined(WIN32)
    static const std::string g_ros_os = "win32";
  #else
    static const std::string g_ros_os = "linux";
  #endif
#endif

class Exception : public std::runtime_error
{
  public:
    Exception(const std::string& what)
            : std::runtime_error(what)
    {}
};

class Stackage
{
  public:
    // \brief name of the stackage
    std::string name_;
    // \brief absolute path to the stackage
    std::string path_;
    // \brief absolute path to the stackage manifest
    std::string manifest_path_;
    // \brief filename of the stackage manifest
    std::string manifest_name_;
    // \brief package's license with a support for multi-license.
    std::vector<std::string> licenses_;
    // \brief have we already loaded the manifest?
    bool manifest_loaded_;
    // \brief TinyXML structure, filled in during parsing
    tinyxml2::XMLDocument manifest_;
    std::vector<Stackage*> deps_;
    bool deps_computed_;
    bool is_wet_package_;
    bool is_metapackage_;

    Stackage(const std::string& name,
             const std::string& path,
             const std::string& manifest_path,
             const std::string& manifest_name) :
            name_(name),
            path_(path),
            manifest_path_(manifest_path),
            manifest_name_(manifest_name),
            manifest_loaded_(false),
            manifest_(true, tinyxml2::COLLAPSE_WHITESPACE),
            deps_computed_(false),
            is_metapackage_(false)
    {
      is_wet_package_ = manifest_name_ == ROSPACKAGE_MANIFEST_NAME;
    }

    void update_wet_information()
    {
      assert(is_wet_package_);
      assert(manifest_loaded_);
      // get name from package.xml instead of folder name
      tinyxml2::XMLElement* root = get_manifest_root(this);
      for(tinyxml2::XMLElement* el = root->FirstChildElement("name"); el; el = el->NextSiblingElement("name"))
      {
        name_ = el->GetText();
        break;
      }
      // Get license texts, where there may be multiple elements for.
      std::string tagname_license = "license";
      for(tinyxml2::XMLElement* el = root->FirstChildElement(tagname_license.c_str()); el; el = el->NextSiblingElement(tagname_license.c_str()))
      {
        licenses_.push_back(el->GetText());
      }
      // check if package is a metapackage
      for(tinyxml2::XMLElement* el = root->FirstChildElement("export"); el; el = el->NextSiblingElement("export"))
      {
        if(el->FirstChildElement("metapackage"))
        {
          is_metapackage_ = true;
          break;
        }
      }
    }

    bool isStack() const
    {
      return manifest_name_ == MANIFEST_TAG_STACK || (is_wet_package_ && is_metapackage_);
    }

    bool isPackage() const
    {
      return manifest_name_ == MANIFEST_TAG_PACKAGE || (is_wet_package_ && !is_metapackage_);
    }

};

class DirectoryCrawlRecord
{
  public:
    std::string path_;
    bool zombie_;
    double start_time_;
    double crawl_time_;
    size_t start_num_pkgs_;
    DirectoryCrawlRecord(std::string path,
                         double start_time,
                         size_t start_num_pkgs) :
            path_(path),
            zombie_(false),
            start_time_(start_time),
            crawl_time_(0.0),
            start_num_pkgs_(start_num_pkgs) {}
};
bool cmpDirectoryCrawlRecord(DirectoryCrawlRecord* i,
                             DirectoryCrawlRecord* j)
{
  return (i->crawl_time_ < j->crawl_time_);
}

// Rosstackage methods (public/protected)
Rosstackage::Rosstackage(const std::string& manifest_name,
                         const std::string& cache_prefix,
                         const std::string& name,
                         const std::string& tag) :
        manifest_name_(manifest_name),
        cache_prefix_(cache_prefix),
        crawled_(false),
        name_(name),
        tag_(tag)
{
}

Rosstackage::~Rosstackage()
{
  clearStackages();
}

void Rosstackage::clearStackages()
{
  for(boost::unordered_map<std::string, Stackage*>::const_iterator it = stackages_.begin();
      it != stackages_.end();
      ++it)
  {
    delete it->second;
  }
  stackages_.clear();
  dups_.clear();
}

void
Rosstackage::logWarn(const std::string& msg,
                     bool append_errno)
{
  log("Warning", msg, append_errno);
}
void
Rosstackage::logError(const std::string& msg,
                      bool append_errno)
{
  log("Error", msg, append_errno);
}

bool
Rosstackage::getSearchPathFromEnv(std::vector<std::string>& sp)
{
  char* rpp = getenv("ROS_PACKAGE_PATH");
  if(rpp)
  {
    // I can't see that boost filesystem has an elegant cross platform
    // representation for this anywhere like qt/python have.
    #if defined(WIN32)
      const char *path_delim = ";";
    #else 
      const char *path_delim = ":";
    #endif

    std::vector<std::string> rpp_strings;
    boost::split(rpp_strings, rpp,
                 boost::is_any_of(path_delim),
                 boost::token_compress_on);
    for(std::vector<std::string>::const_iterator it = rpp_strings.begin();
        it != rpp_strings.end();
        ++it)
    {
      sp.push_back(*it);
    }
  }
  return true;
}

void
Rosstackage::setQuiet(bool quiet)
{
  quiet_ = quiet;
}

bool
Rosstackage::isStackage(const std::string& path)
{
  try
  {
    if(!fs::is_directory(path))
      return false;
  }
  catch(fs::filesystem_error& e)
  {
    logWarn(std::string("error while looking at ") + path + ": " + e.what());
    return false;
  }

  try
  {
    for(fs::directory_iterator dit = fs::directory_iterator(path);
        dit != fs::directory_iterator();
        ++dit)
    {
      if(!fs::is_regular_file(dit->path()))
        continue;

      if(dit->path().filename() == manifest_name_)
        return true;

      // finding a package.xml is acceptable
      if(dit->path().filename() == ROSPACKAGE_MANIFEST_NAME)
        return true;
    }
  }
  catch(fs::filesystem_error& e)
  {
    // suppress logging of error message if reading of directory failed
    // due to missing permission
    if(e.code().value() != EACCES)
    {
      logWarn(std::string("error while crawling ") + path + ": " + e.what() + ";  " + e.code().message());
    }
  }
  return false;
}

void
Rosstackage::crawl(std::vector<std::string> search_path,
                   bool force)
{
  if(!force)
  {
    bool same_search_paths = (search_path == search_paths_);

    // if search paths differ, try to reading the cache corresponding to the new paths
    if(!same_search_paths && readCache())
    {
      // If the cache was valid, then the paths in the cache match the ones
      // we've been asked to crawl.  Store them, so that later, methods
      // like find() can refer to them when recrawling.
      search_paths_ = search_path;
      return;
    }

    if(crawled_ && same_search_paths)
      return;
  }

  // We're about to crawl, so clear internal storage (in case this is the second
  // run in this process).
  clearStackages();
  search_paths_ = search_path;

  std::vector<DirectoryCrawlRecord*> dummy;
  boost::unordered_set<std::string> dummy2;
  for(std::vector<std::string>::const_iterator p = search_paths_.begin();
      p != search_paths_.end();
      ++p)
    crawlDetail(*p, force, 1, false, dummy, dummy2);

  crawled_ = true;

  writeCache();
}

bool
Rosstackage::inStackage(std::string& name)
{
  fs::path path;
  try
  {
    // Search upward, as suggested in #3697.  This method is only used when
    // a package is not given on the command-line, and so should not have
    // performance impact in common usage.
    for(fs::path path = fs::current_path();
        !path.empty();
        path = path.parent_path())
    {
      if(Rosstackage::isStackage(path.string()))
      {
#if !defined(BOOST_FILESYSTEM_VERSION) || (BOOST_FILESYSTEM_VERSION == 2)
        name = fs::path(path).filename();
#else
        // in boostfs3, filename() returns a path, which needs to be stringified
        name = fs::path(path).filename().string();
#endif
        return true;
      }
    }
    // Search failed.
    return false;
  }
  catch(fs::filesystem_error& e)
  {
    // can't determine current directory, or encountered trouble while
    // searching upward; too bad
    return false;
  }
}


bool
Rosstackage::find(const std::string& name, std::string& path)
{
  Stackage* s = findWithRecrawl(name);
  if(s)
  {
    path = s->path_;
    return true;
  }
  else
    return false;
}

bool
Rosstackage::contents(const std::string& name,
                      std::set<std::string>& packages)
{
  Rospack rp2;
  boost::unordered_map<std::string, Stackage*>::const_iterator it = stackages_.find(name);
  if(it != stackages_.end())
  {
    std::vector<std::string> search_paths;
    search_paths.push_back(it->second->path_);
    rp2.crawl(search_paths, true);
    std::set<std::pair<std::string, std::string> > names_paths;
    rp2.list(names_paths);
    for(std::set<std::pair<std::string, std::string> >::const_iterator iit = names_paths.begin();
        iit != names_paths.end();
        ++iit)
      packages.insert(iit->first);
    return true;
  }
  else
  {
    logError(std::string("stack ") + name + " not found");
    return false;
  }
}

bool
Rosstackage::contains(const std::string& name,
                      std::string& stack,
                      std::string& path)
{
  Rospack rp2;
  for(boost::unordered_map<std::string, Stackage*>::const_iterator it = stackages_.begin();
      it != stackages_.end();
      ++it)
  {
    std::vector<std::string> search_paths;
    search_paths.push_back(it->second->path_);
    rp2.crawl(search_paths, true);
    std::set<std::pair<std::string, std::string> > names_paths;
    rp2.list(names_paths);
    for(std::set<std::pair<std::string, std::string> >::const_iterator iit = names_paths.begin();
        iit != names_paths.end();
        ++iit)
    {
      if(iit->first == name)
      {
        stack = it->first;
        path = it->second->path_;
        return true;
      }
    }
  }

  logError(std::string("stack containing package ") + name + " not found");
  return false;
}

void
Rosstackage::list(std::set<std::pair<std::string, std::string> >& list)
{
  for(boost::unordered_map<std::string, Stackage*>::const_iterator it = stackages_.begin();
      it != stackages_.end();
      ++it)
  {
    std::pair<std::string, std::string> item;
    item.first = it->first;
    item.second = it->second->path_;
    list.insert(item);
  }
}

void
Rosstackage::listDuplicates(std::vector<std::string>& dups)
{
  dups.resize(dups_.size());
  int i = 0;
  for(boost::unordered_map<std::string, std::vector<std::string> >::const_iterator it = dups_.begin();
      it != dups_.end();
      ++it)
  {
    dups[i] = it->first;
    i++;
  }
}

void
Rosstackage::listDuplicatesWithPaths(std::map<std::string, std::vector<std::string> >& dups)
{
  dups.clear();
  for(boost::unordered_map<std::string, std::vector<std::string> >::const_iterator it = dups_.begin();
      it != dups_.end();
      ++it)
  {
    dups[it->first].resize(it->second.size());
    int j = 0;
    for(std::vector<std::string>::const_iterator jt = it->second.begin();
        jt != it->second.end();
        ++jt)
    {
      dups[it->first][j] = *jt;
      j++;
    }
  }
}

bool
Rosstackage::deps(const std::string& name, bool direct,
                  std::vector<std::string>& deps)
{
  std::vector<Stackage*> stackages;
  // Disable errors for the first try
  bool old_quiet = quiet_;
  setQuiet(true);
  if(!depsDetail(name, direct, stackages))
  {
    // Recrawl
    crawl(search_paths_, true);
    stackages.clear();
    setQuiet(old_quiet);
    if(!depsDetail(name, direct, stackages))
      return false;
  }
  setQuiet(old_quiet);
  for(std::vector<Stackage*>::const_iterator it = stackages.begin();
      it != stackages.end();
      ++it)
    deps.push_back((*it)->name_);
  return true;
}

bool
Rosstackage::depsOn(const std::string& name, bool direct,
                       std::vector<std::string>& deps)
{
  std::vector<Stackage*> stackages;
  if(!depsOnDetail(name, direct, stackages))
    return false;
  for(std::vector<Stackage*>::const_iterator it = stackages.begin();
      it != stackages.end();
      ++it)
    deps.push_back((*it)->name_);
  return true;
}

bool
Rosstackage::depsIndent(const std::string& name, bool direct,
                        std::vector<std::string>& deps)
{
  Stackage* stackage = findWithRecrawl(name);
  if(!stackage)
    return false;
  try
  {
    computeDeps(stackage);
    std::vector<Stackage*> deps_vec;
    boost::unordered_set<Stackage*> deps_hash;
    std::vector<std::string> indented_deps;
    gatherDepsFull(stackage, direct, POSTORDER, 0, deps_hash, deps_vec, true, indented_deps);
    for(std::vector<std::string>::const_iterator it = indented_deps.begin();
        it != indented_deps.end();
        ++it)
      deps.push_back(*it);
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

bool
Rosstackage::depsWhy(const std::string& from,
                     const std::string& to,
                     std::string& output)
{
  Stackage* from_s = findWithRecrawl(from);
  if(!from_s)
    return false;
  Stackage* to_s = findWithRecrawl(to);
  if(!to_s)
    return false;

  std::list<std::list<Stackage*> > acc_list;
  try
  {
    depsWhyDetail(from_s, to_s, acc_list);
  }
  catch(Exception& e)
  {
    logError(e.what());
    return true;
  }
  output.append(std::string("Dependency chains from ") +
                from + " to " + to + ":\n");
  for(std::list<std::list<Stackage*> >::const_iterator it = acc_list.begin();
      it != acc_list.end();
      ++it)
  {
    output.append("* ");
    for(std::list<Stackage*>::const_iterator iit = it->begin();
        iit != it->end();
        ++iit)
    {
      if(iit != it->begin())
        output.append("-> ");
      output.append((*iit)->name_ + " ");
    }
    output.append("\n");
  }
  return true;
}

bool
Rosstackage::depsManifests(const std::string& name, bool direct,
                           std::vector<std::string>& manifests)
{
  Stackage* stackage = findWithRecrawl(name);
  if(!stackage)
    return false;
  try
  {
    computeDeps(stackage);
    std::vector<Stackage*> deps_vec;
    gatherDeps(stackage, direct, POSTORDER, deps_vec);
    for(std::vector<Stackage*>::const_iterator it = deps_vec.begin();
        it != deps_vec.end();
        ++it)
      manifests.push_back((*it)->manifest_path_);
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

bool
Rosstackage::rosdeps(const std::string& name, bool direct,
                     std::set<std::string>& rosdeps)
{
  Stackage* stackage = findWithRecrawl(name);
  if(!stackage)
    return false;
  try
  {
    computeDeps(stackage);
    std::vector<Stackage*> deps_vec;
    // rosdeps include the current package
    deps_vec.push_back(stackage);
    if(!direct)
      gatherDeps(stackage, direct, POSTORDER, deps_vec);
    for(std::vector<Stackage*>::const_iterator it = deps_vec.begin();
        it != deps_vec.end();
        ++it)
    {
      if (!stackage->is_wet_package_)
      {
        _rosdeps(*it, rosdeps, MANIFEST_TAG_ROSDEP);
      }
      else
      {
        // package format 1 tags
        _rosdeps(*it, rosdeps, "build_depend");
        _rosdeps(*it, rosdeps, "buildtool_depend");
        _rosdeps(*it, rosdeps, "run_depend");
        // package format 2 tags
        _rosdeps(*it, rosdeps, "build_export_depend");
        _rosdeps(*it, rosdeps, "buildtool_export_depend");
        _rosdeps(*it, rosdeps, "exec_depend");
        _rosdeps(*it, rosdeps, "depend");
        _rosdeps(*it, rosdeps, "doc_depend");
        _rosdeps(*it, rosdeps, "test_depend");
      }
    }
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

void
Rosstackage::_rosdeps(Stackage* stackage, std::set<std::string>& rosdeps, const char* tag_name)
{
  tinyxml2::XMLElement* root = get_manifest_root(stackage);
  for(tinyxml2::XMLElement* ele = root->FirstChildElement(tag_name);
      ele;
      ele = ele->NextSiblingElement(tag_name))
  {
    if(!stackage->is_wet_package_)
    {
      const char *att_str;
      if((att_str = ele->Attribute(MANIFEST_ATTR_NAME)))
      {
        rosdeps.insert(std::string("name: ") + att_str);
      }
    }
    else
    {
      const char* dep_pkgname = ele->GetText();
      if(isSysPackage(dep_pkgname))
      {
        rosdeps.insert(std::string("name: ") + dep_pkgname);
      }
    }
  }
}

bool
Rosstackage::vcs(const std::string& name, bool direct,
                 std::vector<std::string>& vcs)
{
  Stackage* stackage = findWithRecrawl(name);
  if(!stackage)
    return false;
  try
  {
    computeDeps(stackage);
    std::vector<Stackage*> deps_vec;
    // vcs include the current package
    deps_vec.push_back(stackage);
    if(!direct)
      gatherDeps(stackage, direct, POSTORDER, deps_vec);
    for(std::vector<Stackage*>::const_iterator it = deps_vec.begin();
        it != deps_vec.end();
        ++it)
    {
      tinyxml2::XMLElement* root = get_manifest_root(*it);
      for(tinyxml2::XMLElement* ele = root->FirstChildElement(MANIFEST_TAG_VERSIONCONTROL);
          ele;
          ele = ele->NextSiblingElement(MANIFEST_TAG_VERSIONCONTROL))
      {
        std::string result;
        const char *att_str;
        if((att_str = ele->Attribute(MANIFEST_ATTR_TYPE)))
        {
          result.append("type: ");
          result.append(att_str);
        }
        if((att_str = ele->Attribute(MANIFEST_ATTR_URL)))
        {
          result.append("\turl: ");
          result.append(att_str);
        }
        vcs.push_back(result);
      }
    }
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

bool
Rosstackage::cpp_exports(const std::string& name, const std::string& type,
                     const std::string& attrib, bool deps_only,
                     std::vector<std::pair<std::string, bool> >& flags)
{
  Stackage* stackage = findWithRecrawl(name);
  if(!stackage)
    return false;

  static bool init_py = false;
  static PyObject* pName;
  static PyObject* pModule;
  static PyObject* pDict;
  static PyObject* pFunc;

  try
  {
    computeDeps(stackage);
    std::vector<Stackage*> deps_vec;
    if(!deps_only)
      deps_vec.push_back(stackage);
    gatherDeps(stackage, false, PREORDER, deps_vec, true);
    for(std::vector<Stackage*>::const_iterator it = deps_vec.begin();
        it != deps_vec.end();
        ++it)
    {
      if(!(*it)->is_wet_package_)
      {
        std::vector<std::string> dry_flags;
        if(!exports_dry_package(*it, "cpp", attrib, dry_flags))
        {
          return false;
        }
        for(std::vector<std::string>::const_iterator it = dry_flags.begin(); it != dry_flags.end(); ++it)
        {
          flags.push_back(std::pair<std::string, bool>(*it, false));
        }
      }
      else
      {
        initPython();
        PyGILState_STATE gstate = PyGILState_Ensure();

        if(!init_py)
        {
          init_py = true;
          pName = PyUnicode_FromString("rosdep2.rospack");
          pModule = PyImport_Import(pName);
          if(!pModule)
          {
            PyErr_Print();
            PyGILState_Release(gstate);
            std::string errmsg = "could not find python module 'rosdep2.rospack'. is rosdep up-to-date (at least 0.10.4)?";
            throw Exception(errmsg);
          }
          pDict = PyModule_GetDict(pModule);
          pFunc = PyDict_GetItemString(pDict, "call_pkg_config");
        }

        if(!PyCallable_Check(pFunc))
        {
          PyErr_Print();
          PyGILState_Release(gstate);
          std::string errmsg = "could not find python function 'rosdep2.rospack.call_pkg_config'. is rosdep up-to-date (at least 0.10.7)?";
          throw Exception(errmsg);
        }

        PyObject* pArgs = PyTuple_New(2);
        PyObject* pOpt = PyUnicode_FromString(type.c_str());
        PyTuple_SetItem(pArgs, 0, pOpt);
        PyObject* pPkg = PyUnicode_FromString((*it)->name_.c_str());
        PyTuple_SetItem(pArgs, 1, pPkg);
        PyObject* pValue = PyObject_CallObject(pFunc, pArgs);
        Py_DECREF(pArgs);

        if(!pValue)
        {
          PyErr_Print();
          PyGILState_Release(gstate);
          std::string errmsg = "could not call python function 'rosdep2.rospack.call_pkg_config'";
          throw Exception(errmsg);
        }
        if(pValue == Py_None)
        {
          Py_DECREF(pValue);
          std::string errmsg = "python function 'rosdep2.rospack.call_pkg_config' could not call 'pkg-config " + type + " " + (*it)->name_ + "' without errors";
          throw Exception(errmsg);
        }

        flags.push_back(std::pair<std::string, bool>(PyBytes_AsString(pValue), true));
        Py_DECREF(pValue);

        // we want to keep the static objects alive for repeated access
        // so skip all garbage collection until process ends
        //Py_DECREF(pFunc);
        //Py_DECREF(pModule);
        //Py_DECREF(pName);
        //Py_Finalize();

        PyGILState_Release(gstate);
      }
    }
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

bool
Rosstackage::reorder_paths(const std::string& paths, std::string& reordered)
{
  static bool init_py = false;
  static PyObject* pName;
  static PyObject* pModule;
  static PyObject* pFunc;

  initPython();
  PyGILState_STATE gstate = PyGILState_Ensure();

  if(!init_py)
  {
    init_py = true;
    pName = PyUnicode_FromString("catkin_pkg.rospack");
    pModule = PyImport_Import(pName);
    if(!pModule)
    {
      PyErr_Print();
      PyGILState_Release(gstate);
      std::string errmsg = "could not find python module 'catkin_pkg.rospack'. is catkin_pkg up-to-date (at least 0.1.8)?";
      throw Exception(errmsg);
    }
    PyObject* pDict = PyModule_GetDict(pModule);
    pFunc = PyDict_GetItemString(pDict, "reorder_paths");
  }

  if(!PyCallable_Check(pFunc))
  {
    PyErr_Print();
    PyGILState_Release(gstate);
    std::string errmsg = "could not find python function 'catkin_pkg.rospack.reorder_paths'. is catkin_pkg up-to-date (at least 0.1.8)?";
    throw Exception(errmsg);
  }


  PyObject* pArgs = PyTuple_New(1);
  PyTuple_SetItem(pArgs, 0, PyUnicode_FromString(paths.c_str()));
  PyObject* pValue = PyObject_CallObject(pFunc, pArgs);
  Py_DECREF(pArgs);

  if(!pValue)
  {
    PyErr_Print();
    PyGILState_Release(gstate);
    std::string errmsg = "could not call python function 'catkin_pkg.rospack.reorder_paths'";
    throw Exception(errmsg);
  }

  reordered = PyUnicode_AsUTF8(pValue);
  Py_DECREF(pValue);

  // we want to keep the static objects alive for repeated access
  // so skip all garbage collection until process ends
  //Py_DECREF(pFunc);
  //Py_DECREF(pModule);
  //Py_DECREF(pName);
  //Py_Finalize();

  PyGILState_Release(gstate);

  return true;
}

bool
Rosstackage::exports(const std::string& name, const std::string& lang,
                     const std::string& attrib, bool deps_only,
                     std::vector<std::string>& flags)
{
  Stackage* stackage = findWithRecrawl(name);
  if(!stackage)
    return false;
  try
  {
    computeDeps(stackage);
    std::vector<Stackage*> deps_vec;
    if(!deps_only)
      deps_vec.push_back(stackage);
    gatherDeps(stackage, false, PREORDER, deps_vec);
    for(std::vector<Stackage*>::const_iterator it = deps_vec.begin();
        it != deps_vec.end();
        ++it)
    {
      if (!exports_dry_package(*it, lang, attrib, flags))
      {
        return false;
      }
    }
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

bool
Rosstackage::exports_dry_package(Stackage* stackage, const std::string& lang,
                     const std::string& attrib,
                     std::vector<std::string>& flags)
{
  tinyxml2::XMLElement* root = get_manifest_root(stackage);
  for(tinyxml2::XMLElement* ele = root->FirstChildElement(MANIFEST_TAG_EXPORT);
      ele;
      ele = ele->NextSiblingElement(MANIFEST_TAG_EXPORT))
  {
    bool os_match = false;
    const char *best_match = NULL;
    for(tinyxml2::XMLElement* ele2 = ele->FirstChildElement(lang.c_str());
        ele2;
        ele2 = ele2->NextSiblingElement(lang.c_str()))
    {
      const char *os_str;
      if ((os_str = ele2->Attribute("os")))
      {
        if(g_ros_os == std::string(os_str))
        {
          if(os_match)
            logWarn(std::string("ignoring duplicate ") + lang + " tag with os=" + os_str + " in export block");
          else
          {
            best_match = ele2->Attribute(attrib.c_str());
            os_match = true;
          }
        }
      }
      if(!os_match)
      {
        if(!best_match)
          best_match = ele2->Attribute(attrib.c_str());
        else
          logWarn(std::string("ignoring duplicate ") + lang + " tag in export block");
      }

    }
    if(best_match)
    {
      std::string expanded_str;
      if(!expandExportString(stackage, best_match, expanded_str))
        return false;
      flags.push_back(expanded_str);
    }
  }
  // We automatically point to msg_gen and msg_srv directories if
  // certain files are present.
  // But only if we're looking for cpp/cflags, #3884.
  if((lang == "cpp") && (attrib == "cflags"))
  {
    fs::path msg_gen = fs::path(stackage->path_) / MSG_GEN_GENERATED_DIR;
    fs::path srv_gen = fs::path(stackage->path_) / SRV_GEN_GENERATED_DIR;
    if(fs::is_regular_file(msg_gen / MSG_GEN_GENERATED_FILE))
    {
      msg_gen /= fs::path("cpp") / "include";
      flags.push_back(std::string("-I" + msg_gen.string()));
    }
    if(fs::is_regular_file(srv_gen / SRV_GEN_GENERATED_FILE))
    {
      srv_gen /= fs::path("cpp") / "include";
      flags.push_back(std::string("-I" + srv_gen.string()));
    }
  }
  return true;
}

bool
Rosstackage::plugins(const std::string& name, const std::string& attrib,
                     const std::string& top,
                     std::vector<std::string>& flags)
{
  // Find everybody who depends directly on the package in question
  std::vector<Stackage*> stackages;
  if(!depsOnDetail(name, true, stackages, true))
    return false;
  // Also look in the package itself
  boost::unordered_map<std::string, Stackage*>::const_iterator it = stackages_.find(name);
  if(it != stackages_.end())
  {
    // don't warn here; it was done in depsOnDetail()
    stackages.push_back(it->second);
  }
  // If top was given, filter to include only those package on which top
  // depends.
  if(top.size())
  {
    std::vector<Stackage*> top_deps;
    if(!depsDetail(top, false, top_deps))
      return false;
    boost::unordered_set<Stackage*> top_deps_set;
    for(std::vector<Stackage*>::iterator it = top_deps.begin();
        it != top_deps.end();
        ++it)
      top_deps_set.insert(*it);
    std::vector<Stackage*>::iterator it = stackages.begin();
    while(it != stackages.end())
    {
      if((*it)->name_ != top &&
         (top_deps_set.find(*it) == top_deps_set.end()))
        it = stackages.erase(it);
      else
        ++it;
    }
  }
  // Now go looking for the manifest data
  for(std::vector<Stackage*>::const_iterator it = stackages.begin();
      it != stackages.end();
      ++it)
  {
    tinyxml2::XMLElement* root = get_manifest_root(*it);
    for(tinyxml2::XMLElement* ele = root->FirstChildElement(MANIFEST_TAG_EXPORT);
        ele;
        ele = ele->NextSiblingElement(MANIFEST_TAG_EXPORT))
    {
      for(tinyxml2::XMLElement* ele2 = ele->FirstChildElement(name.c_str());
          ele2;
          ele2 = ele2->NextSiblingElement(name.c_str()))
      {
        const char *att_str;
        if((att_str = ele2->Attribute(attrib.c_str())))
        {
          std::string expanded_str;
          if(!expandExportString(*it, att_str, expanded_str))
            return false;
          flags.push_back((*it)->name_ + " " + expanded_str);
        }
      }
    }
  }
  return true;
}

bool
Rosstackage::depsMsgSrv(const std::string& name, bool direct,
                        std::vector<std::string>& gens)
{
  Stackage* stackage = findWithRecrawl(name);
  if(!stackage)
    return false;
  try
  {
    computeDeps(stackage);
    std::vector<Stackage*> deps_vec;
    gatherDeps(stackage, direct, POSTORDER, deps_vec);
    for(std::vector<Stackage*>::const_iterator it = deps_vec.begin();
        it != deps_vec.end();
        ++it)
    {
      fs::path msg_gen = fs::path((*it)->path_) /
              MSG_GEN_GENERATED_DIR /
              MSG_GEN_GENERATED_FILE;
      fs::path srv_gen = fs::path((*it)->path_) /
              SRV_GEN_GENERATED_DIR /
              SRV_GEN_GENERATED_FILE;
      if(fs::is_regular_file(msg_gen))
        gens.push_back(msg_gen.string());
      if(fs::is_regular_file(srv_gen))
        gens.push_back(srv_gen.string());
    }
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

// Rosstackage methods (private)

void
Rosstackage::log(const std::string& level,
                 const std::string& msg,
                 bool append_errno)
{
  if(quiet_)
    return;
  fprintf(stderr, "[%s] %s: %s",
          name_.c_str(), level.c_str(), msg.c_str());
  if(append_errno)
    fprintf(stderr, ": %s", strerror(errno));
  fprintf(stderr, "\n");
}


Stackage*
Rosstackage::findWithRecrawl(const std::string& name)
{
  if(stackages_.count(name))
    return stackages_[name];
  else
  {
    // Try to recrawl, in case we loaded from cache
    crawl(search_paths_, true);
    if(stackages_.count(name))
      return stackages_[name];
  }

  logError(get_manifest_type() + " '" + name + "' not found");
  return NULL;
}

bool
Rosstackage::depsDetail(const std::string& name, bool direct,
                        std::vector<Stackage*>& deps)
{
  // No recrawl here, because we're in a recursive function.  Rely on the
  // top level to do it.
  if(!stackages_.count(name))
  {
    logError(std::string("no such package ") + name);
    return false;
  }
  Stackage* stackage = stackages_[name];
  try
  {
    computeDeps(stackage);
    std::vector<Stackage*> deps_vec;
    gatherDeps(stackage, direct, POSTORDER, deps_vec);
    for(std::vector<Stackage*>::const_iterator it = deps_vec.begin();
        it != deps_vec.end();
        ++it)
      deps.push_back(*it);
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

void
Rosstackage::depsWhyDetail(Stackage* from,
                           Stackage* to,
                           std::list<std::list<Stackage*> >& acc_list)
{
  computeDeps(from);
  for(std::vector<Stackage*>::const_iterator it = from->deps_.begin();
      it != from->deps_.end();
      ++it)
  {
    if((*it)->name_ == to->name_)
    {
      std::list<Stackage*> acc;
      acc.push_back(from);
      acc.push_back(to);
      acc_list.push_back(acc);
    }
    else
    {
      std::list<std::list<Stackage*> > l;
      depsWhyDetail(*it, to, l);
      for(std::list<std::list<Stackage*> >::iterator iit = l.begin();
          iit != l.end();
          ++iit)
      {
        iit->push_front(from);
        acc_list.push_back(*iit);
      }
    }
  }
}

bool
Rosstackage::depsOnDetail(const std::string& name, bool direct,
                          std::vector<Stackage*>& deps, bool ignore_missing)
{
  // No recrawl here, because depends-on always forces a crawl at the
  // start.
  if(!stackages_.count(name))
  {
    logError(std::string("no such package ") + name);
    return false;
  }
  try
  {
    for(boost::unordered_map<std::string, Stackage*>::const_iterator it = stackages_.begin();
        it != stackages_.end();
        ++it)
    {
      computeDeps(it->second, true, ignore_missing);
      std::vector<Stackage*> deps_vec;
      gatherDeps(it->second, direct, POSTORDER, deps_vec);
      for(std::vector<Stackage*>::const_iterator iit = deps_vec.begin();
          iit != deps_vec.end();
          ++iit)
      {
        if((*iit)->name_ == name)
        {
          deps.push_back(it->second);
          break;
        }
      }
    }
  }
  catch(Exception& e)
  {
    logError(e.what());
    return false;
  }
  return true;
}

bool
Rosstackage::profile(const std::vector<std::string>& search_path,
                     bool zombie_only,
                     int length,
                     std::vector<std::string>& dirs)
{
  double start = time_since_epoch();
  std::vector<DirectoryCrawlRecord*> dcrs;
  boost::unordered_set<std::string> dcrs_hash;
  for(std::vector<std::string>::const_iterator p = search_path.begin();
      p != search_path.end();
      ++p)
  {
    crawlDetail(*p, true, 1, true, dcrs, dcrs_hash);
  }
  if(!zombie_only)
  {
    double total = time_since_epoch() - start;
    char buf[16];
    snprintf(buf, sizeof(buf), "%.6f", total);
    dirs.push_back(std::string("Full tree crawl took ") + buf + " seconds.");
    dirs.push_back("Directories marked with (*) contain no manifest.  You may");
    dirs.push_back("want to delete these directories.");
    dirs.push_back("To get just of list of directories without manifests,");
    dirs.push_back("re-run the profile with --zombie-only");
    dirs.push_back("-------------------------------------------------------------");
  }
  std::sort(dcrs.begin(), dcrs.end(), cmpDirectoryCrawlRecord);
  std::reverse(dcrs.begin(), dcrs.end());
  int i=0;
  for(std::vector<DirectoryCrawlRecord*>::const_iterator it = dcrs.begin();
      it != dcrs.end();
      ++it)
  {
    if(zombie_only)
    {
      if((*it)->zombie_)
      {
        if(length < 0 || i < length)
          dirs.push_back((*it)->path_);
        i++;
      }
    }
    else
    {
      char buf[16];
      snprintf(buf, sizeof(buf), "%.6f", (*it)->crawl_time_);
      if(length < 0 || i < length)
        dirs.push_back(std::string(buf) + " " +
                       ((*it)->zombie_ ? "* " : "  ") +
                       (*it)->path_);
      i++;
    }
    delete *it;
  }

  writeCache();
  return 0;
}

void
Rosstackage::addStackage(const std::string& path)
{
#if !defined(BOOST_FILESYSTEM_VERSION) || (BOOST_FILESYSTEM_VERSION == 2)
  std::string name = fs::path(path).filename();
#else
  // in boostfs3, filename() returns a path, which needs to be stringified
  std::string name = fs::path(path).filename().string();
#endif

  Stackage* stackage = 0;
  fs::path dry_manifest_path = fs::path(path) / manifest_name_;
  fs::path wet_manifest_path = fs::path(path) / ROSPACKAGE_MANIFEST_NAME;
  if(fs::is_regular_file(dry_manifest_path))
  {
    stackage = new Stackage(name, path, dry_manifest_path.string(), manifest_name_);
  }
  else if(fs::is_regular_file(wet_manifest_path))
  {
    stackage = new Stackage(name, path, wet_manifest_path.string(), ROSPACKAGE_MANIFEST_NAME);
    loadManifest(stackage);
    stackage->update_wet_information();
  }
  else
  {
    return;
  }

  // skip the stackage if it is not of correct type
  if( (stackage->is_wet_package_ &&
       (manifest_name_ == ROSPACKAGE_MANIFEST_NAME)) ||
      (!stackage->is_wet_package_ &&
       (manifest_name_ == ROSSTACK_MANIFEST_NAME && stackage->isPackage()) ||
       (manifest_name_ == ROSPACK_MANIFEST_NAME && stackage->isStack())) )
  {
    delete stackage;
    return;
  }

  if(stackages_.find(stackage->name_) != stackages_.end())
  {
    if (dups_.find(stackage->name_) == dups_.end())
    {
      std::vector<std::string> dups;
      dups.push_back(stackages_[stackage->name_]->path_);
      dups_[stackage->name_] = dups;
    }
    dups_[stackage->name_].push_back(stackage->path_);
    delete stackage;
    return;
  }

  stackages_[stackage->name_] = stackage;
}

void
Rosstackage::crawlDetail(const std::string& path,
                         bool force,
                         int depth,
                         bool collect_profile_data,
                         std::vector<DirectoryCrawlRecord*>& profile_data,
                         boost::unordered_set<std::string>& profile_hash)
{
  if(depth > MAX_CRAWL_DEPTH)
    throw Exception("maximum depth exceeded during crawl");

  try
  {
    if(!fs::is_directory(path))
      return;
  }
  catch(fs::filesystem_error& e)
  {
    logWarn(std::string("error while looking at ") + path + ": " + e.what());
    return;
  }

  fs::path catkin_ignore = fs::path(path) / CATKIN_IGNORE;
  try
  {
    if(fs::is_regular_file(catkin_ignore))
      return;
  }
  catch(fs::filesystem_error& e)
  {
    logWarn(std::string("error while looking for ") + catkin_ignore.string() + ": " + e.what());
  }

  if(isStackage(path))
  {
    addStackage(path);
    return;
  }

  fs::path nosubdirs = fs::path(path) / ROSPACK_NOSUBDIRS;
  try
  {
    if(fs::is_regular_file(nosubdirs))
      return;
  }
  catch(fs::filesystem_error& e)
  {
    logWarn(std::string("error while looking for ") + nosubdirs.string() + ": " + e.what());
  }

  // We've already checked above whether CWD contains the kind of manifest
  // we're looking for.  Don't recurse if we encounter a rospack manifest,
  // to avoid having rosstack finding stacks inside packages, #3816.
  fs::path rospack_manifest = fs::path(path) / ROSPACK_MANIFEST_NAME;
  try
  {
    if(fs::is_regular_file(rospack_manifest))
      return;
  }
  catch(fs::filesystem_error& e)
  {
    logWarn(std::string("error while looking for ") + rospack_manifest.string() + ": " + e.what());
  }

  DirectoryCrawlRecord* dcr = NULL;
  if(collect_profile_data)
  {
    if(profile_hash.find(path) == profile_hash.end())
    {
      dcr = new DirectoryCrawlRecord(path,
                                     time_since_epoch(),
                                     stackages_.size());
      profile_data.push_back(dcr);
      profile_hash.insert(path);
    }
  }

  try
  {
    for(fs::directory_iterator dit = fs::directory_iterator(path);
        dit != fs::directory_iterator();
        ++dit)
    {
      if(fs::is_directory(dit->path()))
      {
#if !defined(BOOST_FILESYSTEM_VERSION) || (BOOST_FILESYSTEM_VERSION == 2)
        std::string name = dit->path().filename();
#else
        // in boostfs3, filename() returns a path, which needs to be stringified
        std::string name = dit->path().filename().string();
#endif
        // Ignore directories starting with '.'
        if(name.size() == 0 || name[0] == '.')
          continue;

        crawlDetail(dit->path().string(), force, depth+1,
                    collect_profile_data, profile_data, profile_hash);
      }
    }
  }
  catch(fs::filesystem_error& e)
  {
    // suppress logging of error message if reading of directory failed
    // due to missing permission
    if(e.code().value() != EACCES)
    {
      logWarn(std::string("error while crawling ") + path + ": " + e.what());
    }
  }

  if(collect_profile_data && dcr != NULL)
  {
    // Measure the elapsed time
    dcr->crawl_time_ = time_since_epoch() - dcr->start_time_;
    // If the number of packages didn't change while crawling,
    // then this directory is a zombie
    if(stackages_.size() == dcr->start_num_pkgs_)
      dcr->zombie_ = true;
  }
}

void
Rosstackage::loadManifest(Stackage* stackage)
{
  if(stackage->manifest_loaded_)
    return;

  if(stackage->manifest_.LoadFile(stackage->manifest_path_.c_str()) != tinyxml2::XML_SUCCESS)
  {
    std::string errmsg = std::string("error parsing manifest of package ") +
            stackage->name_ + " at " + stackage->manifest_path_;
    throw Exception(errmsg);
  }
  stackage->manifest_loaded_ = true;
}

void
Rosstackage::computeDeps(Stackage* stackage, bool ignore_errors, bool ignore_missing)
{
  if(stackage->deps_computed_)
    return;

  stackage->deps_computed_ = true;

  try
  {
    loadManifest(stackage);
    get_manifest_root(stackage);
  }
  catch(Exception& e)
  {
    if(ignore_errors)
      return;
    else
      throw e;
  }
  if (!stackage->is_wet_package_)
  {
    computeDepsInternal(stackage, ignore_errors, "depend", ignore_missing);
  }
  else
  {
    // package format 1 tags
    computeDepsInternal(stackage, ignore_errors, "run_depend", ignore_missing);
    // package format 2 tags
    computeDepsInternal(stackage, ignore_errors, "exec_depend", ignore_missing);
    computeDepsInternal(stackage, ignore_errors, "depend", ignore_missing);
  }
}

void
Rosstackage::computeDepsInternal(Stackage* stackage, bool ignore_errors, const std::string& depend_tag, bool ignore_missing)
{
  tinyxml2::XMLElement* root;
  root = get_manifest_root(stackage);

  const char* dep_pkgname;
  for(tinyxml2::XMLElement *dep_ele = root->FirstChildElement(depend_tag.c_str());
      dep_ele;
      dep_ele = dep_ele->NextSiblingElement(depend_tag.c_str()))
  {
    if (!stackage->is_wet_package_)
    {
      dep_pkgname = dep_ele->Attribute(tag_.c_str());
    }
    else
    {
      dep_pkgname = dep_ele->GetText();
    }
    if(!dep_pkgname)
    {
      if(!ignore_errors)
      {
        std::string errmsg = std::string("bad depend syntax (no 'package/stack' attribute) in manifest ") + stackage->name_ + " at " + stackage->manifest_path_;
        throw Exception(errmsg);
      }
    }
    else if(dep_pkgname == stackage->name_)
    {
      if(!ignore_errors)
      {
        std::string errmsg = get_manifest_type() + " '" + stackage->name_ + "' depends on itself";
        throw Exception(errmsg);
      }
    }
    else if(!stackages_.count(dep_pkgname))
    {
      if (stackage->is_wet_package_ && (ignore_missing || isSysPackage(dep_pkgname)))
      {
        continue;
      }
      if(ignore_errors)
      {
        Stackage* dep =  new Stackage(dep_pkgname, "", "", "");
        stackage->deps_.push_back(dep);
      }
      else
      {
        std::string errmsg = get_manifest_type() + " '" + stackage->name_ + "' depends on non-existent package '" + dep_pkgname + "' and rosdep claims that it is not a system dependency. Check the ROS_PACKAGE_PATH or try calling 'rosdep update'";
        throw Exception(errmsg);
      }
    }
    else
    {
      Stackage* dep = stackages_[dep_pkgname];
      if (std::find(stackage->deps_.begin(), stackage->deps_.end(), dep) == stackage->deps_.end())
      {
        stackage->deps_.push_back(dep);
        computeDeps(dep, ignore_errors, ignore_missing);
      }
    }
  }
}

void
Rosstackage::initPython()
{
  static bool initialized = false;
  if(!initialized)
  {
    initialized = true;
    Py_InitializeEx(0);
  }
}

bool
Rosstackage::isSysPackage(const std::string& pkgname)
{
  static std::map<std::string, bool> cache;
  if(cache.find(pkgname) != cache.end())
  {
    return cache.find(pkgname)->second;
  }

  initPython();
  PyGILState_STATE gstate = PyGILState_Ensure();

  static PyObject* pModule = 0;
  static PyObject* pDict = 0;
  if(!pModule)
  {
    PyObject* pName = PyUnicode_FromString("rosdep2.rospack");
    pModule = PyImport_Import(pName);
    Py_DECREF(pName);
    if(!pModule)
    {
      PyErr_Print();
      PyGILState_Release(gstate);
      std::string errmsg = "could not find python module 'rosdep2.rospack'. is rosdep up-to-date (at least 0.10.4)?";
      throw Exception(errmsg);
    }
    pDict = PyModule_GetDict(pModule);
  }

  static PyObject* pView = 0;
  if(!pView)
  {
    PyObject* pFunc = PyDict_GetItemString(pDict, "init_rospack_interface");
    if(!PyCallable_Check(pFunc))
    {
      PyErr_Print();
      PyGILState_Release(gstate);
      std::string errmsg = "could not find python function 'rosdep2.rospack.init_rospack_interface'. is rosdep up-to-date (at least 0.10.4)?";
      throw Exception(errmsg);
    }
    pView = PyObject_CallObject(pFunc, NULL);
    if(!pView)
    {
      PyErr_Print();
      PyGILState_Release(gstate);
      std::string errmsg = "could not call python function 'rosdep2.rospack.init_rospack_interface'";
      throw Exception(errmsg);
    }
  }
  static bool rospack_view_not_empty = false;
  if(!rospack_view_not_empty)
  {
    PyObject* pFunc = PyDict_GetItemString(pDict, "is_view_empty");
    if(!PyCallable_Check(pFunc))
    {
      PyErr_Print();
      PyGILState_Release(gstate);
      std::string errmsg = "could not find python function 'rosdep2.rospack.is_view_empty'. is rosdep up-to-date (at least 0.10.8)?";
      throw Exception(errmsg);
    }
    PyObject* pArgs = PyTuple_New(1);
    PyTuple_SetItem(pArgs, 0, pView);
    PyObject* pValue = PyObject_CallObject(pFunc, pArgs);
    Py_INCREF(pView); // in order to keep the view when garbaging pArgs
    Py_DECREF(pArgs);
    if(PyObject_IsTrue(pValue))
    {
      PyErr_Print();
      PyGILState_Release(gstate);
      std::string errmsg = "the rosdep view is empty: call 'sudo rosdep init' and 'rosdep update'";
      throw Exception(errmsg);
    }
    rospack_view_not_empty = true;
  }

  PyObject* pFunc = PyDict_GetItemString(pDict, "is_system_dependency");
  if(!PyCallable_Check(pFunc))
  {
    PyErr_Print();
    PyGILState_Release(gstate);
    std::string errmsg = "could not call python function 'rosdep2.rospack.is_system_dependency'. is rosdep up-to-date (at least 0.10.4)?";
    throw Exception(errmsg);
  }

  PyObject* pArgs = PyTuple_New(2);
  PyTuple_SetItem(pArgs, 0, pView);
  PyObject* pDep = PyUnicode_FromString(pkgname.c_str());
  PyTuple_SetItem(pArgs, 1, pDep);
  PyObject* pValue = PyObject_CallObject(pFunc, pArgs);
  Py_INCREF(pView); // in order to keep the view when garbaging pArgs
  Py_DECREF(pArgs);

  bool value = PyObject_IsTrue(pValue);
  Py_DECREF(pValue);

  // we want to keep the static objects alive for repeated access
  // so skip all garbage collection until process ends
  //Py_DECREF(pView);
  //Py_DECREF(pDict);
  //Py_DECREF(pModule);
  //Py_Finalize();

  PyGILState_Release(gstate);

  cache[pkgname] = value;

  return value;
}

void
Rosstackage::gatherDeps(Stackage* stackage, bool direct,
                        traversal_order_t order,
                        std::vector<Stackage*>& deps,
                        bool no_recursion_on_wet)
{
  boost::unordered_set<Stackage*> deps_hash;
  std::vector<std::string> indented_deps;
  gatherDepsFull(stackage, direct, order, 0,
                 deps_hash, deps, false, indented_deps, no_recursion_on_wet);
}

void
_gatherDepsFull(Stackage* stackage, bool direct,
                            traversal_order_t order, int depth,
                            boost::unordered_set<Stackage*>& deps_hash,
                            std::vector<Stackage*>& deps,
                            bool get_indented_deps,
                            std::vector<std::string>& indented_deps,
                            bool no_recursion_on_wet,
                            std::vector<std::string>& dep_chain)
{
  if(stackage->is_wet_package_ && no_recursion_on_wet)
  {
    return;
  }

  if(direct && (stackage->is_wet_package_ || !no_recursion_on_wet))
  {
    for(std::vector<Stackage*>::const_iterator it = stackage->deps_.begin();
        it != stackage->deps_.end();
        ++it)
      deps.push_back(*it);
    return;
  }

  if(depth > MAX_DEPENDENCY_DEPTH) {
    std::string cycle;
    for(std::vector<std::string>::const_iterator it = dep_chain.begin();
        it != dep_chain.end();
        ++it)
    {
      std::vector<std::string>::const_iterator begin = dep_chain.begin();
      std::vector<std::string>::const_iterator cycle_begin = std::find(begin, it, *it);
      if(cycle_begin != it) {
        cycle = ": ";
        for(std::vector<std::string>::const_iterator jt = cycle_begin; jt != it; ++jt) {
          if(jt != cycle_begin) cycle += ", ";
          cycle += *jt;
        }
        break;
      }
    }
    throw Exception(std::string("maximum dependency depth exceeded (likely circular dependency") + cycle + ")");
  }

  for(std::vector<Stackage*>::const_iterator it = stackage->deps_.begin();
      it != stackage->deps_.end();
      ++it)
  {
    if(get_indented_deps)
    {
      std::string indented_dep;
      for(int i=0; i<depth; i++)
        indented_dep.append("  ");
      indented_dep.append((*it)->name_);
        indented_deps.push_back(indented_dep);
    }

    bool first = (deps_hash.find(*it) == deps_hash.end());
    if(first)
    {
      deps_hash.insert(*it);
      // We maintain the vector because the original rospack guaranteed
      // ordering in dep reporting.
      if(order == PREORDER)
        deps.push_back(*it);
    }
    if(!(*it)->is_wet_package_ || !no_recursion_on_wet)
    {
      // We always descend, even if we're encountering this stackage for the
      // nth time, so that we'll throw an error on recursive dependencies
      // (detected via max stack depth being exceeded).
      dep_chain.push_back((*it)->name_);
      _gatherDepsFull(*it, direct, order, depth+1, deps_hash, deps,
                     get_indented_deps, indented_deps,
                     no_recursion_on_wet, dep_chain);
      dep_chain.pop_back();
    }
    if(first)
    {
      if(order == POSTORDER)
        deps.push_back(*it);
    }
  }
}

// Pre-condition: computeDeps(stackage) succeeded
void
Rosstackage::gatherDepsFull(Stackage* stackage, bool direct,
                            traversal_order_t order, int depth,
                            boost::unordered_set<Stackage*>& deps_hash,
                            std::vector<Stackage*>& deps,
                            bool get_indented_deps,
                            std::vector<std::string>& indented_deps,
                            bool no_recursion_on_wet)
{
  std::vector<std::string> dep_chain;
  dep_chain.push_back(stackage->name_);
  _gatherDepsFull(stackage, direct,
      order, depth,
      deps_hash,
      deps,
      get_indented_deps,
      indented_deps,
      no_recursion_on_wet,
      dep_chain);
}

std::string
Rosstackage::getCachePath()
{
  fs::path cache_path;

  char* ros_home = getenv("ROS_HOME");
  if(ros_home)
    cache_path = ros_home;
  else
  {
    // Get the user's home directory by looking up the password entry based
    // on UID.  If that doesn't work, we fall back on examining $HOME,
    // knowing that that can cause trouble when mixed with sudo (#2884).
#if defined(WIN32)
    char* home_drive = getenv("HOMEDRIVE");
    char* home_path = getenv("HOMEPATH");
    if(home_drive && home_path)
      cache_path = fs::path(home_drive) / fs::path(home_path) / fs::path(DOTROS_NAME);
#else // UNIX
    char* home_path;
    struct passwd* passwd_ent;
    // Look up based on effective UID, just in case we got here by set-uid
    if((passwd_ent = getpwuid(geteuid())))
      home_path = passwd_ent->pw_dir;
    else
      home_path = getenv("HOME");
    if(home_path)
      cache_path = fs::path(home_path) / fs::path(DOTROS_NAME);
#endif
  }

  // If it doesn't exist, create the directory that will hold the cache
  try
  {
    if(!fs::is_directory(cache_path))
    {
      fs::create_directory(cache_path);
    }
  }
  catch(fs::filesystem_error& e)
  {
    logWarn(std::string("cannot create rospack cache directory ") +
            cache_path.string() + ": " + e.what());
  }
  cache_path /= cache_prefix_ + "_" + getCacheHash();
  return cache_path.string();
}

std::string
Rosstackage::getCacheHash()
{
  size_t value = 0;
  char* rpp = getenv("ROS_PACKAGE_PATH");
  if(rpp != NULL) {
    boost::hash<std::string> hash_func;
    value = hash_func(rpp);
  }
  char buffer[21];
  snprintf(buffer, 21, "%020lu", value);
  return buffer;
}

bool
Rosstackage::readCache()
{
  FILE* cache = validateCache();
  if(cache)
  {
    // We're about to read from the cache, so clear internal storage (in case this is
    // the second run in this process).
    clearStackages();
    char linebuf[30000];
    for(;;)
    {
      if (!fgets(linebuf, sizeof(linebuf), cache))
        break; // error in read operation
      if (linebuf[0] == '#')
        continue;
      char* newline_pos = strchr(linebuf, '\n');
      if(newline_pos)
        *newline_pos = 0;
      addStackage(linebuf);
    }
    fclose(cache);
    return true;
  }
  else
    return false;
}

// TODO: replace the contents of the method with some fancy cross-platform
// boost thing.
void
Rosstackage::writeCache()
{
  // Write the results of this crawl to the cache file.  At each step, give
  // up on error, printing a warning to stderr.
  std::string cache_path = getCachePath();
  if(!cache_path.size())
  {
    logWarn("no location available to write cache file. Try setting ROS_HOME or HOME.");
  }
  else
  {
    size_t len = cache_path.size() + 1;
    char *tmp_cache_dir = new char[len];
    strncpy(tmp_cache_dir, cache_path.c_str(), len);
#if defined(_MSC_VER)
    // No dirname on Windows; use _splitpath_s instead
    char tmp_cache_path[PATH_MAX];
    char drive[_MAX_DRIVE], dir[_MAX_DIR], fname[_MAX_FNAME], ext[_MAX_EXT];
    _splitpath_s(tmp_cache_dir, drive, _MAX_DRIVE, dir, _MAX_DIR, fname, _MAX_FNAME,
                 ext, _MAX_EXT);
    char full_dir[_MAX_DRIVE + _MAX_DIR];
    _makepath_s(full_dir, _MAX_DRIVE + _MAX_DIR, drive, dir, NULL, NULL);
    snprintf(tmp_cache_path, sizeof(tmp_cache_path), "%s\\.rospack_cache.XXXXXX", full_dir);
#elif defined(__MINGW32__)
    char tmp_cache_path[PATH_MAX];
    char* temp_name = tempnam(dirname(tmp_cache_dir),".rospack_cache.");
    snprintf(tmp_cache_path, sizeof(tmp_cache_path), temp_name);
    delete temp_name;
#else
    char *temp_dirname = dirname(tmp_cache_dir);
    len = strlen(temp_dirname) + 22 + 1;
    char *tmp_cache_path = new char[len];
    snprintf(tmp_cache_path, len, "%s/.rospack_cache.XXXXXX", temp_dirname);
#endif
#if defined(__MINGW32__)
    // There is no equivalent of mkstemp or _mktemp_s on mingw, so we resort to a slightly problematic
    // tempnam (above) and mktemp method. This has the miniscule chance of a race condition.
    int fd = open(tmp_cache_path, O_RDWR | O_EXCL | _O_CREAT, 0644);
    if (fd < 0)
    {
      logWarn(std::string("unable to create temporary cache file ") +
                   tmp_cache_path, true);
    }
    else
    {
      FILE *cache = fdopen(fd, "w");
#elif defined(WIN32)
    if (_mktemp_s(tmp_cache_path, PATH_MAX) != 0)
    {
      fprintf(stderr,
              "[rospack] Unable to generate temporary cache file name: %u",
              GetLastError());
    }
    else
    {
      FILE *cache = fopen(tmp_cache_path, "w");
#else
    int fd = mkstemp(tmp_cache_path);
    if (fd < 0)
    {
      fprintf(stderr, "[rospack] Unable to create temporary cache file %s: %s\n",
              tmp_cache_path, strerror(errno));
    }
    else
    {
      FILE *cache = fdopen(fd, "w");
#endif
      if (!cache)
      {
        fprintf(stderr, "[rospack] Unable open cache file %s: %s\n",
                tmp_cache_path, strerror(errno));
      }
      else
      {
        char *rpp = getenv("ROS_PACKAGE_PATH");
        fprintf(cache, "#ROS_PACKAGE_PATH=%s\n", (rpp ? rpp : ""));
        for(boost::unordered_map<std::string, Stackage*>::const_iterator it = stackages_.begin();
            it != stackages_.end();
            ++it)
          fprintf(cache, "%s\n", it->second->path_.c_str());
        fclose(cache);
        if(fs::exists(cache_path))
          remove(cache_path.c_str());
        if(rename(tmp_cache_path, cache_path.c_str()) < 0)
        {
          fprintf(stderr, "[rospack] Error: failed to rename cache file %s to %s: %s\n",
                  tmp_cache_path, cache_path.c_str(), strerror(errno));
        }
      }
    }
    delete[] tmp_cache_dir;
#if !defined(_MSC_VER) && !defined(__MINGW32__)
    delete[] tmp_cache_path;
#endif
  }
}

FILE*
Rosstackage::validateCache()
{
  std::string cache_path = getCachePath();
  // first see if it's new enough
  double cache_max_age = DEFAULT_MAX_CACHE_AGE;
  const char *user_cache_time_str = getenv("ROS_CACHE_TIMEOUT");
  if(user_cache_time_str)
    cache_max_age = atof(user_cache_time_str);
  if(cache_max_age == 0.0)
    return NULL;
  struct stat s;
  if(stat(cache_path.c_str(), &s) == 0)
  {
    double dt = difftime(time(NULL), s.st_mtime);
    // Negative cache_max_age means it's always new enough.  It's dangerous
    // for the user to set this, but rosbash uses it.
    if ((cache_max_age > 0.0) && (dt > cache_max_age))
      return NULL;
  }
  // try to open it
  FILE* cache = fopen(cache_path.c_str(), "r");
  if(!cache)
    return NULL; // it's not readable by us. sad.

  // see if ROS_PACKAGE_PATH matches
  char linebuf[30000];
  bool ros_package_path_ok = false;
  const char* ros_package_path = getenv("ROS_PACKAGE_PATH");
  for(;;)
  {
    if(!fgets(linebuf, sizeof(linebuf), cache))
      break;
    linebuf[strlen(linebuf)-1] = 0; // get rid of trailing newline
    if (linebuf[0] == '#')
    {
      if(!strncmp("#ROS_PACKAGE_PATH=", linebuf, 18))
      {
        if(!ros_package_path)
        {
          if(!strlen(linebuf+18))
            ros_package_path_ok = true;
        }
        else if(!strcmp(linebuf+18, ros_package_path))
          ros_package_path_ok = true;
      }
    }
    else
      break; // we're out of the header. nothing more matters to this check.
  }
  if(ros_package_path_ok)
  {
    // seek to the beginning and pass back the stream (instead of closing
    // and later reopening, which is a race condition, #1666)
    fseek(cache, 0, SEEK_SET);
    return cache;
  }
  else
  {
    fclose(cache);
    return NULL;
  }
}

bool
Rosstackage::expandExportString(Stackage* stackage,
                                const std::string& instring,
                                std::string& outstring)
{
  outstring = instring;
  for(std::string::size_type i = outstring.find(MANIFEST_PREFIX);
      i != std::string::npos;
      i = outstring.find(MANIFEST_PREFIX))
  {
    outstring.replace(i, std::string(MANIFEST_PREFIX).length(),
                      stackage->path_);
  }

  // skip substitution attempt when the string neither contains
  // a dollar sign for $(command) and $envvar nor
  // a backtick wrapping a command
  if (outstring.find_first_of("$`") == std::string::npos)
  {
    return true;
  }

  // Do backquote substitution.  E.g.,  if we find this string:
  //   `pkg-config --cflags gdk-pixbuf-2.0`
  // We replace it with the result of executing the command
  // contained within the backquotes (reading from its stdout), which
  // might be something like:
  //   -I/usr/include/gtk-2.0 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include

  // Construct and execute the string
  // We do the assignment first to ensure that if backquote expansion (or
  // anything else) fails, we'll get a non-zero exit status from pclose().
  std::string cmd = std::string("ret=\"") + outstring + "\" && echo $ret";

  // Remove embedded newlines
  std::string token("\n");
  for (std::string::size_type s = cmd.find(token);
       s != std::string::npos;
       s = cmd.find(token, s))
    cmd.replace(s,token.length(),std::string(" "));

  FILE* p;
  if(!(p = popen(cmd.c_str(), "r")))
  {
    std::string errmsg =
            std::string("failed to execute backquote expression ") +
            cmd + " in " +
            stackage->manifest_path_;
    logWarn(errmsg, true);
    return false;
  }
  else
  {
    char buf[8192];
    memset(buf,0,sizeof(buf));
    // Read the command's output
    do
    {
      clearerr(p);
      while(fgets(buf + strlen(buf),sizeof(buf)-strlen(buf)-1,p));
    } while(ferror(p) && errno == EINTR);
    // Close the subprocess, checking exit status
    if(pclose(p) != 0)
    {
      std::string errmsg =
              std::string("got non-zero exit status from executing backquote expression ") +
              cmd + " in " +
              stackage->manifest_path_;
      return false;
    }
    else
    {
      // Strip trailing newline, which was added by our call to echo
      buf[strlen(buf)-1] = '\0';
      // Replace the backquote expression with the new text
      outstring = buf;
    }
  }

  return true;
}

// Rospack methods
Rospack::Rospack() :
        Rosstackage(ROSPACK_MANIFEST_NAME,
                    ROSPACK_CACHE_PREFIX,
                    ROSPACK_NAME,
                    MANIFEST_TAG_PACKAGE)
{
}

const char*
Rospack::usage()
{
  return "USAGE: rospack <command> [options] [package]\n"
          "  Allowed commands:\n"
          "    help\n"
          "    cflags-only-I     [--deps-only] [package]\n"
          "    cflags-only-other [--deps-only] [package]\n"
          "    depends           [package] (alias: deps)\n"
          "    depends-indent    [package] (alias: deps-indent)\n"
          "    depends-manifests [package] (alias: deps-manifests)\n"
          "    depends-msgsrv    [package] (alias: deps-msgsrv)\n"
          "    depends-on        [package]\n"
          "    depends-on1       [package]\n"
          "    depends-why --target=<target> [package] (alias: deps-why)\n"
          "    depends1          [package] (alias: deps1)\n"
          "    export [--deps-only] --lang=<lang> --attrib=<attrib> [package]\n"
          "    find [package]\n"
          "    langs\n"
          "    libs-only-L     [--deps-only] [package]\n"
          "    libs-only-l     [--deps-only] [package]\n"
          "    libs-only-other [--deps-only] [package]\n"
          "    list\n"
          "    list-duplicates\n"
          "    list-names\n"
          "    plugins --attrib=<attrib> [--top=<toppkg>] [package]\n"
          "    profile [--length=<length>] [--zombie-only]\n"
          "    rosdep  [package] (alias: rosdeps)\n"
          "    rosdep0 [package] (alias: rosdeps0)\n"
          "    vcs  [package]\n"
          "    vcs0 [package]\n"
          "  Extra options:\n"
          "    -q     Quiets error reports.\n\n"
          " If [package] is omitted, the current working directory\n"
          " is used (if it contains a package.xml or manifest.xml).\n\n";
}

std::string Rospack::get_manifest_type()
{
  return "package";
}

// Rosstack methods
Rosstack::Rosstack() :
        Rosstackage(ROSSTACK_MANIFEST_NAME,
                    ROSSTACK_CACHE_PREFIX,
                    ROSSTACK_NAME,
                    MANIFEST_TAG_STACK)
{
}

const char*
Rosstack::usage()
{
  return "USAGE: rosstack [options] <command> [stack]\n"
          "  Allowed commands:\n"
          "    help\n"
          "    find [stack]\n"
          "    contents [stack]\n"
          "    list\n"
          "    list-names\n"
          "    depends [stack] (alias: deps)\n"
          "    depends-manifests [stack] (alias: deps-manifests)\n"
          "    depends1 [stack] (alias: deps1)\n"
          "    depends-indent [stack] (alias: deps-indent)\n"
          "    depends-why --target=<target> [stack] (alias: deps-why)\n"
          "    depends-on [stack]\n"
          "    depends-on1 [stack]\n"
          "    contains [package]\n"
          "    contains-path [package]\n"
          "    profile [--length=<length>] \n\n"
          " If [stack] is omitted, the current working directory\n"
          " is used (if it contains a stack.xml).\n\n";
}

std::string Rosstack::get_manifest_type()
{
  return "stack";
}

tinyxml2::XMLElement*
get_manifest_root(Stackage* stackage)
{
  tinyxml2::XMLElement* ele = stackage->manifest_.RootElement();
  if(!ele)
  {
    std::string errmsg = std::string("error parsing manifest of package ") +
            stackage->name_ + " at " + stackage->manifest_path_;
    throw Exception(errmsg);
  }
  return ele;
}

double
time_since_epoch()
{
#if defined(WIN32)
  #if defined(_MSC_VER) || defined(_MSC_EXTENSIONS)
    #define DELTA_EPOCH_IN_MICROSECS  11644473600000000Ui64
  #else
    #define DELTA_EPOCH_IN_MICROSECS  11644473600000000ULL
  #endif
  FILETIME ft;
  unsigned __int64 tmpres = 0;

  GetSystemTimeAsFileTime(&ft);
  tmpres |= ft.dwHighDateTime;
  tmpres <<= 32;
  tmpres |= ft.dwLowDateTime;
  tmpres /= 10;
  tmpres -= DELTA_EPOCH_IN_MICROSECS;
  return static_cast<double>(tmpres) / 1e6;
#else
  struct timeval tod;
  gettimeofday(&tod, NULL);
  return tod.tv_sec + 1e-6 * tod.tv_usec;
#endif
}



} // namespace rospack