[cmake] Fetch OpenFST at configure time. (#4558)

CMakeLists.txt

@@ -7,8 +7,11 @@ endif(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake;${CMAKE_MODULE_PATH}")
 include(GNUInstallDirs)
 include(Utils)
+
 include(third_party/get_third_party)
 
+include(cmake/third_party/openfst.cmake)
+
 find_package(PythonInterp)
 if(NOT PYTHON_EXECUTABLE)
     message(FATAL_ERROR "Needs python to auto-generate most CMake files, but not found.")
@@ -172,18 +175,15 @@ endif()
 # get_third_party(openfst)
 # set(OPENFST_ROOT_DIR ${CMAKE_CURRENT_BINARY_DIR}/openfst)
 # include(third_party/openfst_lib_target)
-find_library(OpenFST_LIBRARY
-            NAMES fst
-            PATHS ${CMAKE_CURRENT_SOURCE_DIR}/tools/openfst/lib
-            REQUIRED)
-find_path(OpenFST_INCLUDE_DIR
-            NAMES "fst/fst.h"
-            PATHS "${CMAKE_CURRENT_SOURCE_DIR}/tools/openfst/include"
-            REQUIRED)
-get_filename_component(OpenFST_LIBRARY_DIR ${OpenFST_LIBRARY} DIRECTORY CACHE)
-mark_as_advanced(FORCE OpenFST_INCLUDE_DIR OpenFST_LIBRARY OpenFST_LIBRARY_DIR)
-include_directories(${OpenFST_INCLUDE_DIR})
-link_directories(${OpenFST_LIBRARY_DIR})
+#find_library(OpenFST_LIBRARY
+#            NAMES fst
+#            PATHS ${CMAKE_CURRENT_SOURCE_DIR}/tools/openfst/lib
+#            REQUIRED)
+#find_path(OpenFST_INCLUDE_DIR
+#            NAMES "fst/fst.h"
+#            PATHS "${CMAKE_CURRENT_SOURCE_DIR}/tools/openfst/include"
+#            REQUIRED)
+
 link_libraries(fst)
 
 # add all native libraries

cmake/third_party/openfst.cmake

@@ -1,14 +1,25 @@
-cmake_minimum_required(VERSION 2.8.2)
-project(openfst-download NONE)
-
-include(ExternalProject)
-ExternalProject_Add(openfst
-    GIT_REPOSITORY https://github.com/kkm000/openfst
-    GIT_TAG 0bca6e76d24647427356dc242b0adbf3b5f1a8d9 # tag win/1.7.2.1
-    SOURCE_DIR "${CMAKE_CURRENT_BINARY_DIR}/openfst"
-    BINARY_DIR ""
-    CONFIGURE_COMMAND ""
-    BUILD_COMMAND ""
-    INSTALL_COMMAND ""
-    TEST_COMMAND ""
+cmake_minimum_required(VERSION 3.14)
+include(FetchContent)
+
+FetchContent_Declare(
+        openfst
+        GIT_REPOSITORY  https://github.com/kkm000/openfst
+        GIT_TAG         338225416178ac36b8002d70387f5556e44c8d05 # tag win/1.7.2.1
 )
+
+FetchContent_GetProperties(openfst)
+if(NOT openfst_POPULATED)
+    FetchContent_Populate(openfst)
+    include_directories(${openfst_SOURCE_DIR}/src/include)
+
+    add_subdirectory(${openfst_SOURCE_DIR} ${openfst_BINARY_DIR})
+
+    install(DIRECTORY ${openfst_SOURCE_DIR}/src/include/ DESTINATION include/
+            FILES_MATCHING PATTERN "*.h")
+
+    install(TARGETS fst
+            EXPORT kaldi-targets
+            ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+endif()