add CPack packaging definition

See also:

- https://cmake.org/cmake/help/v3.4/module/CPack.html
- https://cmake.org/cmake/help/v3.4/module/CPackRPM.html
- https://cmake.org/cmake/help/v3.4/module/CPackDeb.html

CMakeLists.txt

@@ -43,13 +43,38 @@ target_link_libraries(${PROJECT_NAME}
   mksh vroot pthread
 )
 
+# default install prefix is /usr/local
+# change it with e.g. -DCMAKE_INSTALL_PREFIX=/usr
 install(TARGETS   ${PROJECT_NAME}  RUNTIME DESTINATION bin)
 install(FILES     man/man1/make.1          DESTINATION share/man/man1)
 install(FILES     bin/make.rules.file      DESTINATION share/${PROJECT_NAME}
         RENAME        make.rules)
 install(FILES     bin/svr4.make.rules.file DESTINATION share/${PROJECT_NAME}
         RENAME        svr4.make.rules)
-install(FILES     README.md                DESTINATION share/doc/${PROJECT_NAME}
+install(FILES     COPYING
+                  README.md
+                                           DESTINATION share/doc/${PROJECT_NAME}
 )
 install(DIRECTORY example                  DESTINATION share/doc/${PROJECT_NAME}
 )
+
+# select the package generator with e.g. -DCPACK_GENERATOR='RPM;DEB'
+set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "illumos dmake, Sun make compatible")
+set(CPACK_PACKAGE_CONTACT "mail@georg.so")
+set(CPACK_PACKAGE_VENDOR "misc")
+set(CPACK_PACKAGE_DESCRIPTION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/README_pkg.txt")
+set(CPACK_RPM_PACKAGE_LICENSE "CDDL")
+# used by some generators like NSI, is only displayed in the installer
+set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/COPYING")
+# only used by some generators
+set(CPACK_PACKAGE_INSTALL_DIRECTORY
+    "${PROJECT_NAME}-${CMake_VERSION_MAJOR}.${CMake_VERSION_MINOR}")
+set(CPACK_PACKAGE_VERSION_MAJOR "0")
+set(CPACK_PACKAGE_VERSION_MINOR "6")
+set(CPACK_PACKAGE_VERSION_PATCH "0")
+set(CPACK_RPM_PACKAGE_GROUP "Development/Tools")
+set(CPACK_RPM_PACKAGE_URL "https://github.com/gsauthof/somake")
+# CPackDeb default to CPACK_PACKAGE_DESCRIPTION_SUMMARY, although
+# the long description makes more sense ...
+file(READ ${CPACK_PACKAGE_DESCRIPTION_FILE} CPACK_DEBIAN_PACKAGE_DESCRIPTION)
+include(CPack)

README.md

@@ -342,6 +342,32 @@ the following order:
 5. `/usr/share/lib/make/make.rules`
 6. `/etc/default/make.rules`
 
+## Packaging
+
+The CMake build file `CMakeLists.txt` also defines some variables
+for CPack, the CMake companion tool for creating binary packages.
+
+For example, to create `.rpm` and `.deb` packages:
+
+    $ cmake ../somake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr \
+        -DCPACK_GENERATOR='RPM;DEB' -GNinja
+    $ ninja-build package
+    $  ls somake-*
+    somake-0.6.0-Linux.deb  somake-0.6.0-Linux.rpm
+
+As always, the `-GNinja` generator option can be dropped -
+`ninja-build` has to be replaced with `make` then.
+
+The content of the archives can be verified like this:
+
+    $ dpkg --contents somake-0.6.0-Linux.deb
+    $ dpkg --info somake-0.6.0-Linux.deb
+
+Or:
+
+    $ rpm2cpio somake-0.6.0-Linux.rpm | cpio --list -v
+    $ rpm -qip somake-0.6.0-Linux.rpm
+
 
 ## License
 

README_pkg.txt

@@ -0,0 +1,15 @@
+`somake` is a portable version of illumos make. illumos make is
+derived from Sun's dmake (distributed make) which in turn is
+compatible with the bonus features of Sun make. Notable Sun make
+features are:
+
+- command dependencies (target is considered outdated if used
+  variable has changed)
+- hidden dependencies (automatic dependency generation for
+  included headers)
+- target groups
+- conditional macro assignment (different syntax than with GNU
+  make)
+- include file generation (similar to GNU make)
+
+See also: https://github.com/gsauthof/somake