CPack-FreeBSD: add a generator for FreeBSD pkg(8)

Adds an option CPACK_ENABLE_FREEBSD_PKG to allow CPack to look
for FreeBSD's libpkg / pkg(8). If this is set and the libpkg
headers and library are found (which they will be, by default,
on any FreeBSD system), then add a FreeBSD pkg(8) generator.

The FreeBSD package tool pkg(8) uses tar.xz files (.txz) with two
metadata files embedded (+MANIFEST and +COMPACT_MANIFEST).
This introduces a bunch of FreeBSD-specific CPACK_FREEBSD_PACKAGE_*
variables for filling in the metadata; the Debian generator does
something similar. Documentation for the CPack CMake-script is styled
after the Debian generator.

Implementation notes:
 - Checks for libpkg -- the underlying implementation for pkg(8) --
   and includes FreeBSD package-generation if building CMake on
   a UNIX host. Since libpkg can be used on BSDs, Linux and OSX,
   this potentially adds one more packaging format. In practice,
   this will only happen on FreeBSD and DragonflyBSD.
 - Copy-paste from cmCPackArchiveGenerator to special-case
   the metadata generation and to run around the internal
   archive generation: use libpkg instead.
 - Generating the metadata files is a little contrived.
 - Most of the validation logic for package settings is in
   CPackFreeBSD.cmake, as well as the code that tries to re-use
   packaging settings that may already be set up for Debian.
 - libpkg has its own notion of output filename, so we have
   another contrived bit of code that munges the output file
   list so that CPack can find the output.
 - Stick with C++98.

10 files changed, 696 insertions, 0 deletions

diff --git a/Copyright.txt b/Copyright.txt
index daaa1d1..b7af4c5 100644
--- a/Copyright.txt
+++ b/Copyright.txt
@@ -34,6 +34,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 The following individuals and institutions are among the Contributors:
 
 * Aaron C. Meadows <cmake@shadowguarddev.com>
+* Adriaan de Groot <groot@kde.org>
 * Aleksey Avdeev <solo@altlinux.ru>
 * Alexander Neundorf <neundorf@kde.org>
 * Alexander Smorkalov <alexander.smorkalov@itseez.com>
diff --git a/Help/manual/cmake-modules.7.rst b/Help/manual/cmake-modules.7.rst
index 4a03b7a..fa6144c 100644
--- a/Help/manual/cmake-modules.7.rst
+++ b/Help/manual/cmake-modules.7.rst
@@ -60,6 +60,7 @@ All Modules
    /module/CPackCygwin
    /module/CPackDeb
    /module/CPackDMG
+   /module/CPackFreeBSD
    /module/CPackIFW
    /module/CPackIFWConfigureFile
    /module/CPackNSIS
diff --git a/Help/module/CPackFreeBSD.rst b/Help/module/CPackFreeBSD.rst
new file mode 100644
index 0000000..083f0cb
--- /dev/null
+++ b/Help/module/CPackFreeBSD.rst
@@ -0,0 +1 @@
+.. cmake-module:: ../../Modules/CPackFreeBSD.cmake
diff --git a/Help/release/dev/cpack-freebsd-pkg.rst b/Help/release/dev/cpack-freebsd-pkg.rst
new file mode 100644
index 0000000..1732581
--- /dev/null
+++ b/Help/release/dev/cpack-freebsd-pkg.rst
@@ -0,0 +1,5 @@
+cpack-freebsd-pkg
+-----------------
+
+* CPack gained a ``FREEBSD`` generator for FreeBSD ``pkg(8)``, configured
+  by the :module:`CPackFreeBSD` module.
diff --git a/Modules/CPack.cmake b/Modules/CPack.cmake
index a63fc83..3915943 100644
--- a/Modules/CPack.cmake
+++ b/Modules/CPack.cmake
@@ -471,6 +471,7 @@ if(NOT CPACK_GENERATOR)
         option(CPACK_BINARY_TZ  "Enable to build TZ packages"     ON)
       endif()
       option(CPACK_BINARY_DEB  "Enable to build Debian packages"  OFF)
+      option(CPACK_BINARY_FREEBSD  "Enable to build FreeBSD packages"  OFF)
       option(CPACK_BINARY_NSIS "Enable to build NSIS packages"    OFF)
       option(CPACK_BINARY_RPM  "Enable to build RPM packages"     OFF)
       option(CPACK_BINARY_STGZ "Enable to build STGZ packages"    ON)
@@ -491,6 +492,7 @@ if(NOT CPACK_GENERATOR)
   cpack_optional_append(CPACK_GENERATOR  CPACK_BINARY_CYGWIN       CygwinBinary)
   cpack_optional_append(CPACK_GENERATOR  CPACK_BINARY_DEB          DEB)
   cpack_optional_append(CPACK_GENERATOR  CPACK_BINARY_DRAGNDROP    DragNDrop)
+  cpack_optional_append(CPACK_GENERATOR  CPACK_BINARY_FREEBSD      FREEBSD)
   cpack_optional_append(CPACK_GENERATOR  CPACK_BINARY_IFW          IFW)
   cpack_optional_append(CPACK_GENERATOR  CPACK_BINARY_NSIS         NSIS)
   cpack_optional_append(CPACK_GENERATOR  CPACK_BINARY_OSXX11       OSXX11)
@@ -542,6 +544,7 @@ mark_as_advanced(
   CPACK_BINARY_CYGWIN
   CPACK_BINARY_DEB
   CPACK_BINARY_DRAGNDROP
+  CPACK_BINARY_FREEBSD
   CPACK_BINARY_IFW
   CPACK_BINARY_NSIS
   CPACK_BINARY_OSXX11
diff --git a/Modules/CPackFreeBSD.cmake b/Modules/CPackFreeBSD.cmake
new file mode 100644
index 0000000..7fec78a
--- /dev/null
+++ b/Modules/CPackFreeBSD.cmake
@@ -0,0 +1,246 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#[=======================================================================[.rst:
+CPackFreeBSD
+------------
+
+The built in (binary) CPack FreeBSD (pkg) generator (Unix only)
+
+Variables specific to CPack FreeBSD (pkg) generator
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+CPackFreeBSD may be used to create pkg(8) packages -- these may be used
+on FreeBSD, DragonflyBSD, NetBSD, OpenBSD, but also on Linux or OSX,
+depending on the installed package-management tools -- using :module:`CPack`.
+
+CPackFreeBSD is a :module:`CPack` generator and uses the ``CPACK_XXX``
+variables used by :module:`CPack`. It tries to re-use packaging information
+that may already be specified for Debian packages for the :module:`CPackDeb`
+generator. it also tries to re-use RPM packaging information when Debian
+does not specify.
+
+CPackFreeBSD generator should work on any host with libpkg installed. The
+packages it produces are specific to the host architecture and ABI.
+
+CPackFreeBSD sets package-metadata through :code:`CPACK_FREEBSD_XXX` variables.
+CPackFreeBSD, unlike CPackDeb, does not specially support componentized
+packages; a single package is created from all the software artifacts
+created through CMake.
+
+All of the variables can be set specifically for FreeBSD packaging in
+the CPackConfig file or in CMakeLists.txt, but most of them have defaults
+that use general settings (e.g. CMAKE_PROJECT_NAME) or Debian-specific
+variables when those make sense (e.g. the homepage of an upstream project
+is usually unchanged by the flavor of packaging). When there is no Debian
+information to fall back on, but the RPM packaging has it, fall back to
+the RPM information (e.g. package license).
+
+.. variable:: CPACK_FREEBSD_PACKAGE_NAME
+
+  Sets the package name (in the package manifest, but also affects the
+  output filename).
+
+  * Mandatory: YES
+  * Default:
+
+    - :variable:`CPACK_PACKAGE_NAME` (this is always set by CPack itself,
+      based on CMAKE_PROJECT_NAME).
+
+.. variable:: CPACK_FREEBSD_PACKAGE_COMMENT
+
+  Sets the package comment. This is the short description displayed by
+  pkg(8) in standard "pkg info" output.
+
+  * Mandatory: YES
+  * Default:
+
+    - :variable:`CPACK_PACKAGE_DESCRIPTION_SUMMARY` (this is always set
+      by CPack itself, if nothing else sets it explicitly).
+    - :variable:`PROJECT_DESCRIPTION` (this can be set with the DESCRIPTION
+      parameter for :command:`project`).
+
+.. variable:: CPACK_FREEBSD_PACKAGE_DESCRIPTION
+
+  Sets the package description. This is the long description of the package,
+  given by "pkg info" with a specific package as argument.
+
+  * Mandatory: YES
+  * Default:
+
+    - :variable:`CPACK_DEBIAN_PACKAGE_DESCRIPTION` (this may be set already
+      for Debian packaging, so we may as well re-use it).
+
+.. variable:: CPACK_FREEBSD_PACKAGE_WWW
+
+  The URL of the web site for this package, preferably (when applicable) the
+  site from which the original source can be obtained and any additional
+  upstream documentation or information may be found.
+
+  * Mandatory: YES
+  * Default:
+
+   - :variable:`CPACK_DEBIAN_PACKAGE_HOMEPAGE` (this may be set already
+     for Debian packaging, so we may as well re-use it).
+
+.. variable:: CPACK_FREEBSD_PACKAGE_LICENSE
+
+  The license, or licenses, which apply to this software package. This must
+  be one or more license-identifiers that pkg recognizes as acceptable license
+  identifiers (e.g. "GPLv2").
+
+  * Mandatory: YES
+  * Default:
+
+    - :variable:`CPACK_RPM_PACKAGE_LICENSE`
+
+.. variable:: CPACK_FREEBSD_PACKAGE_LICENSE_LOGIC
+
+  This variable is only of importance if there is more than one license.
+  The default is "single", which is only applicable to a single license.
+  Other acceptable values are determined by pkg -- those are "dual" or "multi" --
+  meaning choice (OR) or simultaneous (AND) application of the licenses.
+
+  * Mandatory: NO
+  * Default: single
+
+.. variable:: CPACK_FREEBSD_PACKAGE_MAINTAINER
+
+  The FreeBSD maintainer (e.g. kde@freebsd.org) of this package.
+
+  * Mandatory: YES
+  * Default: none
+
+.. variable:: CPACK_FREEBSD_PACKAGE_ORIGIN
+
+  The origin (ports label) of this package; for packages built by CPack
+  outside of the ports system this is of less importance. The default
+  puts the package somewhere under misc/, as a stopgap.
+
+  * Mandatory: YES
+  * Default: misc/<package name>
+
+.. variable:: CPACK_FREEBSD_PACKAGE_CATEGORIES
+
+  The ports categories where this package lives (if it were to be built
+  from ports). If none is set a single category is determined based on
+  the package origin.
+
+  * Mandatory: YES
+  * Default: derived from ORIGIN
+
+.. variable:: CPACK_FREEBSD_PACKAGE_DEPS
+
+  A list of package origins that should be added as package dependencies.
+  These are in the form <category>/<packagename>, e.g. x11/libkonq.
+  No version information needs to be provided (this is not included
+  in the manifest).
+
+  * Mandatory: NO
+  * Default: empty
+#]=======================================================================]
+
+
+
+if(CMAKE_BINARY_DIR)
+  message(FATAL_ERROR "CPackFreeBSD.cmake may only be used by CPack internally.")
+endif()
+
+if(NOT UNIX)
+  message(FATAL_ERROR "CPackFreeBSD.cmake may only be used under UNIX.")
+endif()
+
+
+###
+#
+# These bits are copied from the Debian packaging file; slightly modified.
+# They are used for filling in FreeBSD-packaging variables that can take
+# on values from elsewhere -- e.g. the package description may as well be
+# copied from Debian.
+#
+function(_cpack_freebsd_fallback_var OUTPUT_VAR_NAME)
+  set(FALLBACK_VAR_NAMES ${ARGN})
+
+  set(VALUE "${${OUTPUT_VAR_NAME}}")
+  if(VALUE)
+    return()
+  endif()
+
+  foreach(variable_name IN LISTS FALLBACK_VAR_NAMES)
+    if(${variable_name})
+      set(${OUTPUT_VAR_NAME} "${${variable_name}}" PARENT_SCOPE)
+      set(VALUE "${${variable_name}}")
+      break()
+    endif()
+  endforeach()
+  if(NOT VALUE)
+    message(WARNING "Variable ${OUTPUT_VAR_NAME} could not be given a fallback value from any variable ${FALLBACK_VAR_NAMES}.")
+  endif()
+endfunction()
+
+function(check_required_var VAR_NAME)
+  if(NOT ${VAR_NAME})
+    message(FATAL_ERROR "Variable ${VAR_NAME} is not set.")
+  endif()
+endfunction()
+
+set(_cpack_freebsd_fallback_origin "misc/bogus")
+
+_cpack_freebsd_fallback_var("CPACK_FREEBSD_PACKAGE_NAME"
+    "CPACK_PACKAGE_NAME"
+    "CMAKE_PROJECT_NAME"
+    )
+
+set(_cpack_freebsd_fallback_www "http://example.com/?pkg=${CPACK_FREEBSD_PACKAGE_NAME}")
+
+_cpack_freebsd_fallback_var("CPACK_FREEBSD_PACKAGE_COMMENT"
+    "CPACK_PACKAGE_DESCRIPTION_SUMMARY"
+    )
+
+# TODO: maybe read the PACKAGE_DESCRIPTION file for the longer
+#       FreeBSD pkg-descr?
+_cpack_freebsd_fallback_var("CPACK_FREEBSD_PACKAGE_DESCRIPTION"
+    "CPACK_DEBIAN_PACKAGE_DESCRIPTION"
+    "CPACK_PACKAGE_DESCRIPTION_SUMMARY"
+    "PACKAGE_DESCRIPTION"
+    )
+
+# There's really only one homepage for a project, so
+# re-use the Debian setting if it's there.
+_cpack_freebsd_fallback_var("CPACK_FREEBSD_PACKAGE_WWW"
+    "CPACK_DEBIAN_PACKAGE_HOMEPAGE"
+    "_cpack_freebsd_fallback_www"
+    )
+
+_cpack_freebsd_fallback_var("CPACK_FREEBSD_PACKAGE_VERSION"
+    "CMAKE_PROJECT_VERSION"
+    "${CMAKE_PROJECT_NAME}_VERSION"
+    "PROJECT_VERSION"
+    "CPACK_PACKAGE_VERSION"
+    "CPACK_PACKAGE_VERSION"
+    )
+
+_cpack_freebsd_fallback_var("CPACK_FREEBSD_PACKAGE_MAINTAINER"
+    "CPACK_PACKAGE_CONTACT"
+    )
+
+_cpack_freebsd_fallback_var("CPACK_FREEBSD_PACKAGE_LICENSE"
+    "CPACK_RPM_PACKAGE_LICENSE"
+    )
+
+_cpack_freebsd_fallback_var("CPACK_FREEBSD_PACKAGE_ORIGIN"
+  "_cpack_freebsd_fallback_origin"
+  )
+
+if(NOT CPACK_FREEBSD_PACKAGE_CATEGORIES)
+  string(REGEX REPLACE "/.*" "" CPACK_FREEBSD_PACKAGE_CATEGORIES ${CPACK_FREEBSD_PACKAGE_ORIGIN})
+endif()
+
+check_required_var("CPACK_FREEBSD_PACKAGE_NAME")
+check_required_var("CPACK_FREEBSD_PACKAGE_ORIGIN")
+check_required_var("CPACK_FREEBSD_PACKAGE_VERSION")
+check_required_var("CPACK_FREEBSD_PACKAGE_MAINTAINER")
+check_required_var("CPACK_FREEBSD_PACKAGE_COMMENT")
+check_required_var("CPACK_FREEBSD_PACKAGE_DESCRIPTION")
+check_required_var("CPACK_FREEBSD_PACKAGE_WWW")
+check_required_var("CPACK_FREEBSD_PACKAGE_LICENSE")
diff --git a/Source/CMakeLists.txt b/Source/CMakeLists.txt
index 40403ca..1878b8a 100644
--- a/Source/CMakeLists.txt
+++ b/Source/CMakeLists.txt
@@ -896,11 +896,40 @@ if(CYGWIN)
     )
 endif()
 
+option(CPACK_ENABLE_FREEBSD_PKG "Add FreeBSD pkg(8) generator to CPack." OFF)
+
 if(UNIX)
   set(CPACK_SRCS ${CPACK_SRCS}
     CPack/cmCPackDebGenerator.cxx
     CPack/cmCPackRPMGenerator.cxx
     )
+
+  # Optionally, try to use pkg(8)
+  if(CPACK_ENABLE_FREEBSD_PKG)
+    # On UNIX, you may find FreeBSD's pkg(8) and attendant
+    # library -- it can be used on FreeBSD, Dragonfly, NetBSD,
+    # OpenBSD and also Linux and OSX. Look for the header and
+    # the library; it's a warning on FreeBSD if they're not
+    # found, and informational on other platforms.
+    find_path(FREEBSD_PKG_INCLUDE_DIRS "pkg.h" PATHS /usr/local)
+    if(FREEBSD_PKG_INCLUDE_DIRS)
+      find_library(FREEBSD_PKG_LIBRARIES
+        pkg
+        DOC "FreeBSD pkg(8) library")
+      if(FREEBSD_PKG_LIBRARIES)
+        set(CPACK_SRCS ${CPACK_SRCS}
+          CPack/cmCPackFreeBSDGenerator.cxx
+          )
+      endif()
+    endif()
+
+    if (NOT FREEBSD_PKG_INCLUDE_DIRS OR NOT FREEBSD_PKG_LIBRARIES)
+      message(FATAL_ERROR "CPack needs libpkg(3) to produce FreeBSD packages natively.")
+    endif()
+  else()
+    set(FREEBSD_PKG_INCLUDE_DIRS NOTFOUND)
+    set(FREEBSD_PKG_LIBRARIES NOTFOUND)
+  endif()
 endif()
 
 if(WIN32)
@@ -958,6 +987,11 @@ if(APPLE)
       "See CMakeFiles/CMakeError.log for details of the failure.")
   endif()
 endif()
+if(CPACK_ENABLE_FREEBSD_PKG AND FREEBSD_PKG_INCLUDE_DIRS AND FREEBSD_PKG_LIBRARIES)
+  target_link_libraries(CPackLib ${FREEBSD_PKG_LIBRARIES})
+  include_directories(${FREEBSD_PKG_INCLUDE_DIRS})
+  add_definitions(-DHAVE_FREEBSD_PKG)
+endif()
 
 if(APPLE)
   add_executable(cmakexbuild cmakexbuild.cxx)
diff --git a/Source/CPack/cmCPackFreeBSDGenerator.cxx b/Source/CPack/cmCPackFreeBSDGenerator.cxx
new file mode 100644
index 0000000..ae17b79
--- /dev/null
+++ b/Source/CPack/cmCPackFreeBSDGenerator.cxx
@@ -0,0 +1,359 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#include "cmCPackFreeBSDGenerator.h"
+
+#include "cmArchiveWrite.h"
+#include "cmCPackArchiveGenerator.h"
+#include "cmCPackLog.h"
+#include "cmGeneratedFileStream.h"
+#include "cmSystemTools.h"
+
+// Needed for ::open() and ::stat()
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <pkg.h>
+
+#include <algorithm>
+
+cmCPackFreeBSDGenerator::cmCPackFreeBSDGenerator()
+  : cmCPackArchiveGenerator(cmArchiveWrite::CompressXZ, "paxr")
+{
+}
+
+int cmCPackFreeBSDGenerator::InitializeInternal()
+{
+  this->SetOptionIfNotSet("CPACK_PACKAGING_INSTALL_PREFIX", "/usr/local");
+  this->SetOption("CPACK_INCLUDE_TOPLEVEL_DIRECTORY", "0");
+  return this->Superclass::InitializeInternal();
+}
+
+cmCPackFreeBSDGenerator::~cmCPackFreeBSDGenerator()
+{
+}
+
+// This is a wrapper, for use only in stream-based output,
+// that will output a string in UCL escaped fashion (in particular,
+// quotes and backslashes are escaped). The list of characters
+// to escape is taken from https://github.com/vstakhov/libucl
+// (which is the reference implementation pkg(8) refers to).
+class EscapeQuotes
+{
+public:
+  const std::string& value;
+
+  EscapeQuotes(const std::string& s)
+    : value(s)
+  {
+  }
+};
+
+// Output a string as "string" with escaping applied.
+cmGeneratedFileStream& operator<<(cmGeneratedFileStream& s,
+                                  const EscapeQuotes& v)
+{
+  s << '"';
+  for (std::string::size_type i = 0; i < v.value.length(); ++i) {
+    char c = v.value[i];
+    switch (c) {
+      case '\n':
+        s << "\\n";
+        break;
+      case '\r':
+        s << "\\r";
+        break;
+      case '\b':
+        s << "\\b";
+        break;
+      case '\t':
+        s << "\\t";
+        break;
+      case '\f':
+        s << "\\f";
+        break;
+      case '\\':
+        s << "\\\\";
+        break;
+      case '"':
+        s << "\\\"";
+        break;
+      default:
+        s << c;
+        break;
+    }
+  }
+  s << '"';
+  return s;
+}
+
+// The following classes are all helpers for writing out the UCL
+// manifest file (it also looks like JSON). ManifestKey just has
+// a (string-valued) key; subclasses add a specific kind of
+// value-type to the key, and implement write_value() to output
+// the corresponding UCL.
+class ManifestKey
+{
+public:
+  std::string key;
+
+  ManifestKey(const std::string& k)
+    : key(k)
+  {
+  }
+
+  virtual ~ManifestKey() {}
+
+  // Output the value associated with this key to the stream @p s.
+  // Format is to be decided by subclasses.
+  virtual void write_value(cmGeneratedFileStream& s) const = 0;
+};
+
+// Basic string-value (e.g. "name": "cmake")
+class ManifestKeyValue : public ManifestKey
+{
+public:
+  std::string value;
+
+  ManifestKeyValue(const std::string& k, const std::string& v)
+    : ManifestKey(k)
+    , value(v)
+  {
+  }
+
+  void write_value(cmGeneratedFileStream& s) const CM_OVERRIDE
+  {
+    s << EscapeQuotes(value);
+  }
+};
+
+// List-of-strings values (e.g. "licenses": ["GPLv2", "LGPLv2"])
+class ManifestKeyListValue : public ManifestKey
+{
+public:
+  typedef std::vector<std::string> VList;
+  VList value;
+
+  ManifestKeyListValue(const std::string& k)
+    : ManifestKey(k)
+  {
+  }
+
+  ManifestKeyListValue& operator<<(const std::string& v)
+  {
+    value.push_back(v);
+    return *this;
+  }
+
+  ManifestKeyListValue& operator<<(const std::vector<std::string>& v)
+  {
+    for (VList::const_iterator it = v.begin(); it != v.end(); ++it) {
+      (*this) << (*it);
+    }
+    return *this;
+  }
+
+  void write_value(cmGeneratedFileStream& s) const CM_OVERRIDE
+  {
+    bool with_comma = false;
+
+    s << '[';
+    for (VList::const_iterator it = value.begin(); it != value.end(); ++it) {
+      s << (with_comma ? ',' : ' ');
+      s << EscapeQuotes(*it);
+      with_comma = true;
+    }
+    s << " ]";
+  }
+};
+
+// Deps: actually a dictionary, but we'll treat it as a
+// list so we only name the deps, and produce dictionary-
+// like output via write_value()
+class ManifestKeyDepsValue : public ManifestKeyListValue
+{
+public:
+  ManifestKeyDepsValue(const std::string& k)
+    : ManifestKeyListValue(k)
+  {
+  }
+
+  void write_value(cmGeneratedFileStream& s) const CM_OVERRIDE
+  {
+    s << "{\n";
+    for (VList::const_iterator it = value.begin(); it != value.end(); ++it) {
+      s << "  \"" << *it << "\": {\"origin\": \"" << *it << "\"},\n";
+    }
+    s << '}';
+  }
+};
+
+// Write one of the key-value classes (above) to the stream @p s
+cmGeneratedFileStream& operator<<(cmGeneratedFileStream& s,
+                                  const ManifestKey& v)
+{
+  s << '"' << v.key << "\": ";
+  v.write_value(s);
+  s << ",\n";
+  return s;
+}
+
+// Look up variable; if no value is set, returns an empty string;
+// basically a wrapper that handles the NULL-ptr return from GetOption().
+std::string cmCPackFreeBSDGenerator::var_lookup(const char* var_name)
+{
+  const char* pv = this->GetOption(var_name);
+  if (!pv) {
+    return std::string();
+  } else {
+    return pv;
+  }
+}
+
+// Produce UCL in the given @p manifest file for the common
+// manifest fields (common to the compact and regular formats),
+// by reading the CPACK_FREEBSD_* variables.
+void cmCPackFreeBSDGenerator::write_manifest_fields(
+  cmGeneratedFileStream& manifest)
+{
+  manifest << ManifestKeyValue("name",
+                               var_lookup("CPACK_FREEBSD_PACKAGE_NAME"));
+  manifest << ManifestKeyValue("origin",
+                               var_lookup("CPACK_FREEBSD_PACKAGE_ORIGIN"));
+  manifest << ManifestKeyValue("version",
+                               var_lookup("CPACK_FREEBSD_PACKAGE_VERSION"));
+  manifest << ManifestKeyValue("maintainer",
+                               var_lookup("CPACK_FREEBSD_PACKAGE_MAINTAINER"));
+  manifest << ManifestKeyValue("comment",
+                               var_lookup("CPACK_FREEBSD_PACKAGE_COMMENT"));
+  manifest << ManifestKeyValue(
+    "desc", var_lookup("CPACK_FREEBSD_PACKAGE_DESCRIPTION"));
+  manifest << ManifestKeyValue("www", var_lookup("CPACK_FREEBSD_PACKAGE_WWW"));
+  std::vector<std::string> licenses;
+  cmSystemTools::ExpandListArgument(
+    var_lookup("CPACK_FREEBSD_PACKAGE_LICENSE"), licenses);
+  std::string licenselogic("single");
+  if (licenses.size() < 1) {
+    cmSystemTools::SetFatalErrorOccured();
+  } else if (licenses.size() > 1) {
+    licenselogic = var_lookup("CPACK_FREEBSD_PACKAGE_LICENSE_LOGIC");
+  }
+  manifest << ManifestKeyValue("licenselogic", licenselogic);
+  manifest << (ManifestKeyListValue("licenses") << licenses);
+  std::vector<std::string> categories;
+  cmSystemTools::ExpandListArgument(
+    var_lookup("CPACK_FREEBSD_PACKAGE_CATEGORIES"), categories);
+  manifest << (ManifestKeyListValue("categories") << categories);
+  manifest << ManifestKeyValue("prefix", var_lookup("CMAKE_INSTALL_PREFIX"));
+  std::vector<std::string> deps;
+  cmSystemTools::ExpandListArgument(var_lookup("CPACK_FREEBSD_PACKAGE_DEPS"),
+                                    deps);
+  if (deps.size() > 0) {
+    manifest << (ManifestKeyDepsValue("deps") << deps);
+  }
+}
+
+// Package only actual files; others are ignored (in particular,
+// intermediate subdirectories are ignored).
+static bool ignore_file(const std::string& filename)
+{
+  struct stat statbuf;
+
+  if (!((stat(filename.c_str(), &statbuf) >= 0) &&
+        ((statbuf.st_mode & S_IFMT) == S_IFREG))) {
+    return true;
+  }
+  // May be other reasons to return false
+  return false;
+}
+
+// Write the given list of @p files to the manifest stream @p s,
+// as the UCL field "files" (which is dictionary-valued, to
+// associate filenames with hashes). All the files are transformed
+// to paths relative to @p toplevel, with a leading / (since the paths
+// in FreeBSD package files are supposed to be absolute).
+void write_manifest_files(cmGeneratedFileStream& s,
+                          const std::string& toplevel,
+                          const std::vector<std::string>& files)
+{
+  const char* c_toplevel = toplevel.c_str();
+  std::vector<std::string>::const_iterator it;
+
+  s << "\"files\": {\n";
+  for (it = files.begin(); it != files.end(); ++it) {
+    s << "  \"/" << cmSystemTools::RelativePath(c_toplevel, it->c_str())
+      << "\": \""
+      << "<sha256>"
+      << "\",\n";
+  }
+  s << "  },\n";
+}
+
+static bool has_suffix(const std::string& str, const std::string& suffix)
+{
+  return str.size() >= suffix.size() &&
+    str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0;
+}
+
+int cmCPackFreeBSDGenerator::PackageFiles()
+{
+  if (!this->ReadListFile("CPackFreeBSD.cmake")) {
+    cmCPackLogger(cmCPackLog::LOG_ERROR,
+                  "Error while execution CPackFreeBSD.cmake" << std::endl);
+    return 0;
+  }
+
+  std::vector<std::string>::const_iterator fileIt;
+  std::string dir = cmSystemTools::GetCurrentWorkingDirectory();
+  cmSystemTools::ChangeDirectory(toplevel);
+
+  files.erase(std::remove_if(files.begin(), files.end(), ignore_file),
+              files.end());
+
+  std::string manifestname = toplevel + "/+MANIFEST";
+  {
+    cmGeneratedFileStream manifest(manifestname.c_str());
+    manifest << "{\n";
+    write_manifest_fields(manifest);
+    write_manifest_files(manifest, toplevel, files);
+    manifest << "}\n";
+  }
+
+  cmCPackLogger(cmCPackLog::LOG_DEBUG, "Toplevel: " << toplevel << std::endl);
+
+  if (WantsComponentInstallation()) {
+    // CASE 1 : COMPONENT ALL-IN-ONE package
+    // If ALL COMPONENTS in ONE package has been requested
+    // then the package file is unique and should be open here.
+    if (componentPackageMethod == ONE_PACKAGE) {
+      return PackageComponentsAllInOne();
+    }
+    // CASE 2 : COMPONENT CLASSICAL package(s) (i.e. not all-in-one)
+    // There will be 1 package for each component group
+    // however one may require to ignore component group and
+    // in this case you'll get 1 package for each component.
+    return PackageComponents(componentPackageMethod ==
+                             ONE_PACKAGE_PER_COMPONENT);
+  }
+
+  std::string output_dir =
+    cmSystemTools::CollapseCombinedPath(toplevel, "../");
+  pkg_create_from_manifest(output_dir.c_str(), ::TXZ, toplevel.c_str(),
+                           manifestname.c_str(), NULL);
+
+  std::string broken_suffix = std::string("-") +
+    var_lookup("CPACK_TOPLEVEL_TAG") + std::string(GetOutputExtension());
+  for (std::vector<std::string>::iterator it = packageFileNames.begin();
+       it != packageFileNames.end(); ++it) {
+    cmCPackLogger(cmCPackLog::LOG_DEBUG, "Packagefile " << *it << std::endl);
+    if (has_suffix(*it, broken_suffix)) {
+      it->replace(it->size() - broken_suffix.size(), std::string::npos,
+                  GetOutputExtension());
+      break;
+    }
+  }
+
+  cmSystemTools::ChangeDirectory(dir);
+  return 1;
+}
diff --git a/Source/CPack/cmCPackFreeBSDGenerator.h b/Source/CPack/cmCPackFreeBSDGenerator.h
new file mode 100644
index 0000000..230f728
--- /dev/null
+++ b/Source/CPack/cmCPackFreeBSDGenerator.h
@@ -0,0 +1,37 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#ifndef cmCPackFreeBSDGenerator_h
+#define cmCPackFreeBSDGenerator_h
+
+#include <cmConfigure.h>
+
+#include "cmCPackArchiveGenerator.h"
+#include "cmCPackGenerator.h"
+
+class cmGeneratedFileStream;
+
+/** \class cmCPackFreeBSDGenerator
+ * \brief A generator for FreeBSD package files (TXZ with a manifest)
+ *
+ */
+class cmCPackFreeBSDGenerator : public cmCPackArchiveGenerator
+{
+public:
+  cmCPackTypeMacro(cmCPackFreeBSDGenerator, cmCPackArchiveGenerator);
+  /**
+   * Construct generator
+   */
+  cmCPackFreeBSDGenerator();
+  ~cmCPackFreeBSDGenerator() CM_OVERRIDE;
+
+  int InitializeInternal() CM_OVERRIDE;
+  int PackageFiles() CM_OVERRIDE;
+
+protected:
+  const char* GetOutputExtension() CM_OVERRIDE { return ".txz"; }
+
+  std::string var_lookup(const char* var_name);
+  void write_manifest_fields(cmGeneratedFileStream&);
+};
+
+#endif
diff --git a/Source/CPack/cmCPackGeneratorFactory.cxx b/Source/CPack/cmCPackGeneratorFactory.cxx
index 31f48c7..f135059 100644
--- a/Source/CPack/cmCPackGeneratorFactory.cxx
+++ b/Source/CPack/cmCPackGeneratorFactory.cxx
@@ -9,6 +9,9 @@
 #include "IFW/cmCPackIFWGenerator.h"
 #include "cmAlgorithms.h"
 #include "cmCPack7zGenerator.h"
+#ifdef HAVE_FREEBSD_PKG
+#include "cmCPackFreeBSDGenerator.h"
+#endif
 #include "cmCPackGenerator.h"
 #include "cmCPackLog.h"
 #include "cmCPackNSISGenerator.h"
@@ -132,6 +135,12 @@ cmCPackGeneratorFactory::cmCPackGeneratorFactory()
                             cmCPackRPMGenerator::CreateGenerator);
   }
 #endif
+#ifdef HAVE_FREEBSD_PKG
+  if (cmCPackFreeBSDGenerator::CanGenerate()) {
+    this->RegisterGenerator("FREEBSD", "FreeBSD pkg(8) packages",
+                            cmCPackFreeBSDGenerator::CreateGenerator);
+  }
+#endif
 }
 
 cmCPackGeneratorFactory::~cmCPackGeneratorFactory()