cmake: some improvements

* not depending on "-dev" packages for the built Debian package
* some refactoring in if-clauses and with "quotes"
* libvterm dependency: if something is missing, made clear what

.gitignore

@@ -1,2 +1,3 @@
 build/
 sandbox/
+VERSION

.vscode/settings.json

@@ -54,5 +54,6 @@
         "stdexcept": "cpp",
         "typeinfo": "cpp",
         "pointers": "cpp"
-    }
+    },
+    "C_Cpp.default.configurationProvider": "ms-vscode.cmake-tools"
 }

App.cpp

@@ -3,8 +3,8 @@
  */
 
 #include "App.hpp"
-#include "Window.hpp"
 #include "Debug.hpp"
+#include <NCursesPtyWindow/Window.hpp>
 
 #include <unistd.h>
 #include <utmp.h>

CMakeLists.txt

@@ -1,52 +1,62 @@
+##
 # @author Christian Burger <christian@krikkel.de>
 
 cmake_minimum_required(VERSION 3.16.3)
+
+include("cmake/version.cmake")
 project(NCursesPtyWindow
-        VERSION 0.1.0
-        HOMEPAGE_URL "https://gitea.xndr.de/christian/shellipt")
-### 3.16.3 does not pick up the project's homepage URL by itself
+        HOMEPAGE_URL "https://gitea.xndr.de/christian/NCursesPtyWindow"
+        VERSION ${SEMANTIC_VERSION})
 
 set(CMAKE_CXX_STANDARD 17)
 
 include(CTest)
 enable_testing()
 
-include(ExternalProject)
-include("cmake/ncurses.cmake")
-include("cmake/gsl.cmake")
-
 add_library(NCursesPtyWindow Window.cpp SingleUserInput.cpp Debug.cpp)
 
+### path to own system includes
+include_directories(SYSTEM "${CMAKE_SOURCE_DIR}/include")
+
 ### libraries
 
+include("cmake/ncurses.cmake")
+target_link_libraries(NCursesPtyWindow ${CURSES_LIBRARIES})
+
+include("cmake/gsl.cmake")
+
 include("cmake/libvterm.cmake")
 if(EXISTS libvtermProject)
     add_dependencies(NCursesPtyWindow libvtermProject)
 endif()
+target_link_libraries(NCursesPtyWindow ${LIBVTERM_LIBRARY})
 
 find_library(UTIL_LIBRARY util)
+target_link_libraries(NCursesPtyWindow ${UTIL_LIBRARY})
 
-target_link_libraries(NCursesPtyWindow ${CURSES_LIBRARIES} ${LIBVTERM_LIBRARY} ${UTIL_LIBRARY})
-
-### threads
 set(THREADS_PREFER_PTHREAD_FLAG true)
 find_package(Threads REQUIRED)
 target_link_libraries(NCursesPtyWindow Threads::Threads)
 
 ### demo application
 add_executable(NCursesPtyApp main.cpp App.cpp)
-target_link_libraries(NCursesPtyApp ${CURSES_LIBRARIES} NCursesPtyWindow)
+target_link_libraries(NCursesPtyApp NCursesPtyWindow)
 
 ### installation and packaging
-set_target_properties(NCursesPtyWindow PROPERTIES PUBLIC_HEADER "Window.hpp;SingleUserInput.hpp")
-install(TARGETS NCursesPtyWindow ARCHIVE PUBLIC_HEADER)
+set(NCURSES_PTY_WINDOW_SYSTEM_INCLUDE "include/NCursesPtyWindow")
+set_target_properties(NCursesPtyWindow PROPERTIES PUBLIC_HEADER "${NCURSES_PTY_WINDOW_SYSTEM_INCLUDE}/Window.hpp;${NCURSES_PTY_WINDOW_SYSTEM_INCLUDE}/SingleUserInput.hpp"
+                                       VERSION "${CMAKE_PROJECT_VERSION}")
+include(GNUInstallDirs)
+install(TARGETS NCursesPtyWindow ARCHIVE
+                                 PUBLIC_HEADER DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/NCursesPtyWindow/")
 
 set(CPACK_PROJECT_NAME ${PROJECT_NAME})
 set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
 set(CPACK_PACKAGE_CONTACT "Christian Burger <christian@krikkel.de>")
 set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "Library for a pseudo terminal where the host end is a ncurses window")
+# 3.16.3 does not pick up the project's homepage URL by itself
 set(CPACK_DEBIAN_PACKAGE_HOMEPAGE ${CMAKE_PROJECT_HOMEPAGE_URL})
 
 set(CPACK_GENERATOR "DEB" "TGZ")
-set(CPACK_DEBIAN_PACKAGE_DEPENDS "libncursesw6 (>=6.2), libvterm-dev (>= 0.1.2)")
+set(CPACK_DEBIAN_PACKAGE_DEPENDS "libncursesw6 (>=6.2), libvterm0 (>= 0.1.2)")
 include(CPack)

SingleUserInput.cpp

@@ -2,7 +2,7 @@
  * @author Christian Burger (christian@krikkel.de)
  */
 
-#include "SingleUserInput.hpp"
+#include <NCursesPtyWindow/SingleUserInput.hpp>
 #include "Debug.hpp"
 
 #include <vterm.h>

Window.cpp

@@ -2,7 +2,7 @@
  * @author Christian Burger (christian@krikkel.de)
  */
 
-#include "Window.hpp"
+#include <NCursesPtyWindow/Window.hpp>
 #include "Debug.hpp"
 
 #include <cstdio>

cmake/gsl.cmake

@@ -1,9 +1,11 @@
+##
+# @brief Includes Microsoft's "C++ Guidelines Standard Library"
 # @author Christian Burger <christian@krikkel.de>
 
-find_path(GSL_INCLUDE_DIR "gsl")
-if(GSL_INCLUDE_DIR STREQUAL "GSL_INCLUDE_DIR-NOTFOUND")
+find_path(GSL_INCLUDE_DIR "gsl/gsl" REQUIRED)
+if(NOT GSL_INCLUDE_DIR)
     message(SEND_ERROR "Microsoft GSL not found.")
 else()
-    message(STATUS "Microsoft GSL found.")
+    message(STATUS "Found Microsoft C++ GSL.")
     include_directories(SYSTEM ${GSL_INCLUDE_DIR})
 endif()

cmake/libvterm.cmake

@@ -1,17 +1,31 @@
-# @author Christian Burger <christian@krikkel.de>
-# @brief searches for libvterm and builds it if not found
+##
+# @brief Includes `libvterm` (builds it if not found on the system).
 #
-# provides LIBVTERM_LIBRARY and include path
-# dependency must be added like this:
-# if(EXISTS libvtermProject)
+# Provides ${LIBVTERM_LIBRARY} and implicitly adds path for correct
+# `#include<>`.
+#
+# @warning dependency must be added like this:
+#          if(TARGET libvtermProject)
 #              add_dependencies(<targetDependingOn> libvtermProject)
 #          endif()
+#
+# @author Christian Burger <christian@krikkel.de>
 
 
-find_library(LIBVTERM_LIBRARY NAMES libvterm.so.0.0.2 vterm)
+find_library(LIBVTERM_LIBRARY NAMES "libvterm.so.0.0.2" "vterm")
+find_path(LIBVTERM_INCLUDE "vterm.h")
 
-if(LIBVTERM_LIBRARY STREQUAL "LIBVTERM_LIBRARY-NOTFOUND")
-    message(STATUS "libvterm not found — building it")
+if(NOT LIBVTERM_LIBRARY)
+    message(STATUS "Did not find `libvterm.so`.")
+    set(LIBVTERM_BUILD_IT TRUE)
+endif()
+if(NOT LIBVTERM_INCLUDE)
+    message(STATUS "Did not find `vterm.h`.")
+    set(LIBVTERM_BUILD_IT TRUE)
+endif()
+if(LIBVTERM_BUILD_IT)
+    include(ExternalProject)
+    message(STATUS "Did not find libvterm (see previous error) — building it.")
     ExternalProject_Add(
         libvtermProject
         DOWNLOAD_COMMAND URL "https://launchpad.net/ubuntu/+archive/primary/+sourcefiles/libvterm/0.1.2-2/libvterm_0.1.2.orig.tar.gz"
@@ -22,4 +36,6 @@ if(LIBVTERM_LIBRARY STREQUAL "LIBVTERM_LIBRARY-NOTFOUND")
     ExternalProject_Get_property(libvtermProject SOURCE_DIR)
     set(LIBVTERM_LIBRARY "${SOURCE_DIR}/.libs/libvterm.a")
     include_directories(SYSTEM "${SOURCE_DIR}/include")
+else()
+    message(STATUS "Found vterm library.")
 endif()

cmake/ncurses.cmake

@@ -1,3 +1,5 @@
+##
+# @brief Includes the UTF-8 C++ version of the `ncurses` library.
 # @author Christian Burger <christian@krikkel.de>
 
 set(CURSES_NEED_NCURSES TRUE)
@@ -6,8 +8,8 @@ find_package(Curses 6.2 REQUIRED)
 include_directories(SYSTEM ${CURSES_INCLUDE_DIRS})
 
 # find C++ interface for ncurses with unicode support
-find_library(CURSES_CPP_WIDE_LIBRARY NAMES ncurses++w REQUIRED)
+find_library(CURSES_CPP_WIDE_LIBRARY NAMES ncurses++w)
 if(NOT CURSES_CPP_WIDE_LIBRARY)
-    message(FATAL_ERROR "C++ interface for ncurses (wide/unicode) not found.")
+    message(SEND_ERROR "C++ interface for ncurses (wide/unicode) not found.")
 endif()
 list(APPEND CURSES_LIBRARIES ${CURSES_CPP_WIDE_LIBRARY})

cmake/version.cmake

@@ -0,0 +1,77 @@
+##
+# @brief a ${SEMANTIC_VERSION} based on Git tags (or a `VERSION` file) à la
+#        `v<major>.<minor>.<patch>` is provided
+#
+# Versions have the format "v<major>.<minor>.<patch>" in accordance with
+# Semantic Versioning. If a version is provided by a file named `VERSION`, the
+# full version must be given. If a version is provided by Git tags, only part of
+# the version must be given, the format is then: "v<major>.<minor>". The <patch>
+# version is automatically deduced from the distance in commits to the latest
+# Git tag. The version set in the file overrides the tags in the Git repository.
+#
+# based upon Semantic Versioning: https://semver.org/
+#
+# @attention The <patch> version-part is a bit flaky; it gives the distance in
+#            commits to the <major>.<minor> version. Due to the non-linear
+#            nature of the commit history (because of branches), it is ambigous
+#            (i. e. multiple commits can be found at the same distance). On top
+#            of that, it is your job to make sure, that patches only fix bugs
+#            and do not change the API (no new functionalty; or old removed).
+#
+#            One option to address both issues is: Stay in one branch for
+#            releases — for example named 'release' — and cherry-pick new
+#            versions into the branch (alphas, betas, candidates and releases).
+#            Optional: squash cherry-picked commits, so that the <patch> part of
+#            the version is only incremented by one.
+# @warning To update the version you have to run CMake again.
+#
+# @todo escape/quote paths
+# @todo test cases for CMake file components?
+# @todo make variables local (see: unset()) and put them in a "namespace"
+# @author Christian Burger <christian@krikkel.de>
+find_package(Git)
+
+function(get_semantic_version)
+    if(EXISTS "${CMAKE_SOURCE_DIR}/VERSION")
+        message(STATUS "using file `VERSION` to determine version")
+        file(READ "VERSION" REPOSITORY_VERSION)
+    elseif(GIT_FOUND)
+        message(STATUS "using Git to determine project version")
+        execute_process(COMMAND ${GIT_EXECUTABLE} -C ${CMAKE_SOURCE_DIR} describe --always --match v[0-9]*.[0-9]*
+                        OUTPUT_VARIABLE REPOSITORY_VERSION)
+    else()
+        message(WARNING "We need Git or a file \"VERSION\" to determine a version (e. g. \"v1.0\").")
+    endif()
+
+    # test cases
+    #set(REPOSITORY_VERSION "v0.1") # = 0.1.0
+    #set(REPOSITORY_VERSION "v0.1-1-g12345678") # = 0.1.1
+    #set(REPOSITORY_VERSION "v0.1") # = 0.0.0
+    #set(REPOSITORY_VERSION "1234abcd") # = 0.0.0
+    #set(REPOSITORY_VERSION "") # = 0.1.0
+
+    string(REGEX MATCH "^v([0-9]+)\.([0-9]+)([-\\.]([0-9]+))?" SEMANTIC_VERSION_PREPROCESSED "${REPOSITORY_VERSION}")
+
+    if("${SEMANTIC_VERSION_PREPROCESSED}" STREQUAL "")
+        message(STATUS "Found no version tag (e. g. \"v1.0\").")
+    endif()
+
+    set(SEMANTIC_VERSION_MAJOR ${CMAKE_MATCH_1})
+    set(SEMANTIC_VERSION_MINOR ${CMAKE_MATCH_2})
+    set(SEMANTIC_VERSION_PATCH ${CMAKE_MATCH_4})
+
+    if("${SEMANTIC_VERSION_MAJOR}" STREQUAL "")
+        set(SEMANTIC_VERSION "0.0.0")
+    else()
+        if("${SEMANTIC_VERSION_PATCH}" STREQUAL "")
+            set(SEMANTIC_VERSION_PATCH "0")
+        endif()
+        set(SEMANTIC_VERSION "${SEMANTIC_VERSION_MAJOR}.${SEMANTIC_VERSION_MINOR}.${SEMANTIC_VERSION_PATCH}")
+    endif()
+
+    message(STATUS "Project version is: ${SEMANTIC_VERSION}")
+
+    set(SEMANTIC_VERSION "${SEMANTIC_VERSION}" PARENT_SCOPE)
+endfunction()
+
+get_semantic_version()