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.

1 files changed, 34 insertions, 0 deletions

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)