adding pkg support (#940)

Author: lemire

.github/workflows/pkg.yml

@@ -0,0 +1,29 @@
+name: Debian pkg-config
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  pkg-config:
+    runs-on: ubuntu-latest
+    container:
+      image: debian:12
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Install dependencies
+      run: |
+        apt -y update
+        apt -y --no-install-recommends install g++ cmake make pkg-config
+
+    - name: Build and install
+      run: |
+        cmake -B build
+        cmake --build build
+        cmake --install build
+
+    - name: Test pkg-config
+      run: pkg-config --cflags --libs ada

CMakeLists.txt

@@ -163,6 +163,18 @@ install(
   COMPONENT example_development
 )
 
+
+# pkg-config
+include(cmake/JoinPaths.cmake)
+join_paths(PKGCONFIG_INCLUDEDIR "\${prefix}" "${CMAKE_INSTALL_INCLUDEDIR}")
+join_paths(PKGCONFIG_LIBDIR "\${prefix}" "${CMAKE_INSTALL_LIBDIR}")
+
+configure_file("ada.pc.in" "ada.pc" @ONLY)
+install(
+  FILES "${CMAKE_CURRENT_BINARY_DIR}/ada.pc"
+  DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig"
+)
+
 if(is_top_project)
   set(CPACK_PACKAGE_VENDOR "Ada Authors")
   set(CPACK_PACKAGE_CONTACT "yagiz@nizipli.com")

ada.pc.in

@@ -0,0 +1,11 @@
+prefix=@CMAKE_INSTALL_PREFIX@
+includedir=@PKGCONFIG_INCLUDEDIR@
+libdir=@PKGCONFIG_LIBDIR@
+
+Name: @PROJECT_NAME@
+Description: @PROJECT_DESCRIPTION@
+URL: @PROJECT_HOMEPAGE_URL@
+Version: @PROJECT_VERSION@
+Cflags: -I${includedir} @PKGCONFIG_CFLAGS@
+Libs: -L${libdir} -l@PROJECT_NAME@
+@PKGCONFIG_LIBS_PRIVATE@

cmake/JoinPaths.cmake

@@ -0,0 +1,13 @@
+function(join_paths joined_path first_path_segment)
+  set(temp_path "${first_path_segment}")
+  foreach(current_segment IN LISTS ARGN)
+    if(NOT ("${current_segment}" STREQUAL ""))
+      if(IS_ABSOLUTE "${current_segment}")
+        set(temp_path "${current_segment}")
+      else()
+        set(temp_path "${temp_path}/${current_segment}")
+      endif()
+    endif()
+  endforeach()
+  set(${joined_path} "${temp_path}" PARENT_SCOPE)
+endfunction()