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, 37 insertions, 0 deletions

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