cmake: generate fasttext.pc for pkg-config (#916)

Summary:
Closes: https://github.com/facebookresearch/fastText/issues/915
Pull Request resolved: https://github.com/facebookresearch/fastText/pull/916

Reviewed By: EdouardGrave, tscmoo

Differential Revision: D17737706

Pulled By: Celebio

fbshipit-source-id: 8ee38ee0430e08260d498f446c4475ee4ad62629

CMakeLists.txt

@@ -49,6 +49,13 @@ set(SOURCE_FILES
     src/utils.cc
     src/vector.cc)
 
+
+if (NOT MSVC)
+  include(GNUInstallDirs)
+  configure_file("fasttext.pc.in" "fasttext.pc" @ONLY)
+  install(FILES "${CMAKE_BINARY_DIR}/fasttext.pc" DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+endif()
+
 add_library(fasttext-shared SHARED ${SOURCE_FILES} ${HEADER_FILES})
 add_library(fasttext-static STATIC ${SOURCE_FILES} ${HEADER_FILES})
 add_library(fasttext-static_pic STATIC ${SOURCE_FILES} ${HEADER_FILES})

fasttext.pc.in

@@ -0,0 +1,10 @@
+prefix=@CMAKE_INSTALL_PREFIX@
+exec_prefix=@CMAKE_INSTALL_FULL_LIBEXECDIR@
+libdir=@CMAKE_INSTALL_FULL_LIBDIR@
+includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
+
+Name: @PROJECT_NAME@
+Description: Efficient learning of word representations and sentence classification
+Version: @PROJECT_VERSION@
+Libs: -L${libdir} -lfasttext
+Cflags: -I${includedir}