Fix a number of packaging issues (#423)

* cmake: set PROJECT_DESCRIPTION and PROJECT_HOMEPAGE_URL after project()

Otherwise they are set to an empty string.

* cmake: set the pkg-config URL field

Since the information is already there to set it.

* cmake: use CMAKE_INSTALL_DATAROOTDIR if CMAKE_LIBRARY_ARCHITECTURE is unset

This causes files on NixOS to be put in the proper architecture
independent place, which otherwise was selecting the architecture
dependent location.

* cmake: Properly set pkg-config requires when configured with ICU

In this case the pkg-config file needs to set icu-cu in the `Required`
field, and needs to add the flag `-DCXXOPTS_USE_UNICODE` to the `Cflags`
field.

* cmake: cxxopts is not arch independent when built with ICU support

Since it links to an architecture dependent ICU

CMakeLists.txt

@@ -21,8 +21,6 @@ cmake_minimum_required(VERSION 3.1...3.19)
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/")
 include(cxxopts)
-set("PROJECT_DESCRIPTION" "A header-only lightweight C++ command line option parser")
-set("PROJECT_HOMEPAGE_URL" "https://github.com/jarro2783/cxxopts")
 
 # Get the version of the library
 cxxopts_getversion(VERSION)
@@ -32,6 +30,9 @@ project(cxxopts
     LANGUAGES CXX
 )
 
+set("PROJECT_DESCRIPTION" "A header-only lightweight C++ command line option parser")
+set("PROJECT_HOMEPAGE_URL" "https://github.com/jarro2783/cxxopts")
+
 # Must include after the project call due to GNUInstallDirs requiring a language be enabled (IE. CXX)
 include(GNUInstallDirs)
 

cmake/cxxopts.cmake

@@ -87,10 +87,17 @@ endfunction()
 
 # Helper function to ecapsulate install logic
 function(cxxopts_install_logic)
-    if(CMAKE_LIBRARY_ARCHITECTURE)
-        string(REPLACE "/${CMAKE_LIBRARY_ARCHITECTURE}" "" CMAKE_INSTALL_LIBDIR_ARCHIND "${CMAKE_INSTALL_LIBDIR}")
+    if(NOT CXXOPTS_USE_UNICODE_HELP)
+        if(CMAKE_LIBRARY_ARCHITECTURE)
+            string(REPLACE "/${CMAKE_LIBRARY_ARCHITECTURE}" "" CMAKE_INSTALL_LIBDIR_ARCHIND "${CMAKE_INSTALL_LIBDIR}")
+        else()
+            # On some systems (e.g. NixOS), `CMAKE_LIBRARY_ARCHITECTURE` can be empty
+            set(CMAKE_INSTALL_LIBDIR_ARCHIND "${CMAKE_INSTALL_DATAROOTDIR}")
+        endif()
+        if(${CMAKE_VERSION} VERSION_GREATER "3.14")
+            set(OPTIONAL_ARCH_INDEPENDENT "ARCH_INDEPENDENT")
+        endif()
     else()
-        # On some systems (e.g. NixOS), `CMAKE_LIBRARY_ARCHITECTURE` can be empty
         set(CMAKE_INSTALL_LIBDIR_ARCHIND "${CMAKE_INSTALL_LIBDIR}")
     endif()
     set(CXXOPTS_CMAKE_DIR "${CMAKE_INSTALL_LIBDIR_ARCHIND}/cmake/cxxopts" CACHE STRING "Installation directory for cmake files, relative to ${CMAKE_INSTALL_PREFIX}.")
@@ -99,11 +106,6 @@ function(cxxopts_install_logic)
     set(targets_export_name cxxopts-targets)
     set(PackagingTemplatesDir "${PROJECT_SOURCE_DIR}/packaging")
 
-
-    if(${CMAKE_VERSION} VERSION_GREATER "3.14")
-        set(OPTIONAL_ARCH_INDEPENDENT "ARCH_INDEPENDENT")
-    endif()
-
     # Generate the version, config and target files into the build directory.
     write_basic_package_version_file(
         ${version_config}
@@ -154,6 +156,10 @@ function(cxxopts_install_logic)
     set(CPACK_DEBIAN_COMPRESSION_TYPE "xz")
 
     set(PKG_CONFIG_FILE_NAME "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc")
+    if(CXXOPTS_USE_UNICODE_HELP)
+        set(PKG_CONFIG_REQUIRES "icu-cu")
+        set(PKG_CONFIG_EXTRA_CFLAGS "-DCXXOPTS_USE_UNICODE")
+    endif()
     configure_file("${PackagingTemplatesDir}/pkgconfig.pc.in" "${PKG_CONFIG_FILE_NAME}" @ONLY)
     install(FILES "${PKG_CONFIG_FILE_NAME}"
             DESTINATION "${CMAKE_INSTALL_LIBDIR_ARCHIND}/pkgconfig"

packaging/pkgconfig.pc.in

@@ -3,5 +3,7 @@ includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
 
 Name: @PROJECT_NAME@
 Description: @PROJECT_DESCRIPTION@
+URL: @PROJECT_HOMEPAGE_URL@
 Version: @PROJECT_VERSION@
-Cflags: -I${includedir}
+Requires: @PKG_CONFIG_REQUIRES@
+Cflags: -I${includedir} @PKG_CONFIG_EXTRA_CFLAGS@