Add pkg-config file

Generate and install a toxcore.pc file to be used with pkg-config.

cmake/InstallPkgConfigFile.cmake

@@ -0,0 +1,78 @@
+# A Macro to simplify creating a pkg-config file
+
+# install_pkg_config_file(<package-name> 
+#                              [VERSION <version>]
+#                              [DESCRIPTION <description>]
+#                              [CFLAGS <cflag> ...]
+#                              [LIBS <lflag> ...]
+#                              [REQUIRES <required-package-name> ...])
+# 
+# Create and install a pkg-config .pc file to CMAKE_INSTALL_PREFIX/lib/pkgconfig
+#	assuming the following install layout:
+#	       libraries:   CMAKE_INSTALL_PREFIX/lib
+#	       headers  :   CMAKE_INSTALL_PREFIX/include
+#
+# example:
+#    add_library(mylib mylib.c)
+#    install_pkg_config_file(mylib 
+#			     	DESCRIPTION My Library
+#			     	CFLAGS
+#			     	LIBS -lmylib 
+#			     	REQUIRES glib-2.0 lcm
+# 			     	VERSION 0.0.1)
+#
+#
+function(install_pkg_config_file)
+    list(GET ARGV 0 pc_name)
+    # TODO error check
+
+    set(pc_version 0.0.1)
+    set(pc_description ${pc_name})
+    set(pc_requires "")
+    set(pc_libs "")
+    set(pc_cflags "")
+    set(pc_fname "${CMAKE_BINARY_DIR}/lib/pkgconfig/${pc_name}.pc")
+    
+    set(modewords LIBS CFLAGS REQUIRES VERSION DESCRIPTION)
+    set(curmode "")
+
+    # parse function arguments and populate pkg-config parameters
+    list(REMOVE_AT ARGV 0)
+    foreach(word ${ARGV})
+        list(FIND modewords ${word} mode_index)
+        if(${mode_index} GREATER -1)
+            set(curmode ${word})
+        elseif(curmode STREQUAL LIBS)
+            set(pc_libs "${pc_libs} ${word}")
+        elseif(curmode STREQUAL CFLAGS)
+            set(pc_cflags "${pc_cflags} ${word}")
+        elseif(curmode STREQUAL REQUIRES)
+            set(pc_requires "${pc_requires} ${word}")
+        elseif(curmode STREQUAL VERSION)
+            set(pc_version ${word})
+            set(curmode "")
+        elseif(curmode STREQUAL DESCRIPTION)
+            set(pc_description "${word}")
+            set(curmode "")
+        else(${mode_index} GREATER -1)
+            message("WARNING incorrect use of install_pkg_config_file (${word})")
+            break()
+        endif(${mode_index} GREATER -1)
+    endforeach(word)
+
+    # write the .pc file out
+    file(WRITE ${pc_fname}
+        "prefix=${CMAKE_INSTALL_PREFIX}\n"
+        "libdir=\${prefix}/lib\n"
+        "includedir=\${prefix}/include\n"
+        "\n"
+        "Name: ${pc_name}\n"
+        "Description: ${pc_description}\n"
+        "Requires: ${pc_requires}\n"
+        "Version: ${pc_version}\n"
+        "Libs: -L\${libdir} ${pc_libs}\n"
+        "Cflags: -I\${includedir} ${pc_cflags}\n")
+
+    # mark the .pc file for installation to the lib/pkgconfig directory
+    install(FILES ${pc_fname} DESTINATION lib/pkgconfig)    
+endfunction(install_pkg_config_file)

core/CMakeLists.txt

@@ -37,3 +37,9 @@ if(WIN32)
 	target_link_libraries(toxcore ws2_32)
 endif()
 
+execute_process(COMMAND git rev-list HEAD --count OUTPUT_VARIABLE COMMIT)
+
+# Write pkgconfig-file:
+include(InstallPkgConfigFile)
+install_pkg_config_file(toxcore CFLAGS LIBS -ltoxcore REQUIRES VERSION 0.1.1_r${COMMIT})
+