CMake: promote bba to a true subproject.

CMakeLists.txt

@@ -238,7 +238,21 @@ if(MINGW)
     add_definitions("-Wa,-mbig-obj")
 endif(MINGW)
 
-include(bba/bba.cmake)
+if(CMAKE_CROSSCOMPILING)
+    set(BBA_IMPORT "IMPORTFILE-NOTFOUND" CACHE FILEPATH
+        "Path to the `bba-export.cmake` export file from a native build")
+    include(${BBA_IMPORT})
+else()
+    add_subdirectory(bba)
+endif()
+
+include(TestBigEndian)
+test_big_endian(IS_BIG_ENDIAN)
+if(IS_BIG_ENDIAN)
+    set(BBASM_ENDIAN_FLAG "--be")
+else()
+    set(BBASM_ENDIAN_FLAG "--le")
+endif()
 
 foreach (family ${ARCH})
     message(STATUS "Configuring architecture : ${family}")

bba/CMakeLists.txt

@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 3.3)
+project(bba)
+
+find_package(Boost REQUIRED COMPONENTS
+    program_options
+    filesystem
+    system)
+
+add_executable(bbasm
+    main.cc)
+target_link_libraries(bbasm LINK_PRIVATE
+    ${Boost_PROGRAM_OPTIONS_LIBRARY}
+    ${Boost_FILESYSTEM_LIBRARY}
+    ${Boost_SYSTEM_LIBRARY})
+export(TARGETS bbasm FILE ${CMAKE_BINARY_DIR}/bba-export.cmake)

bba/bba.cmake

@@ -1,21 +0,0 @@
-IF(CMAKE_CROSSCOMPILING)
-    SET(IMPORT_EXECUTABLES "IMPORTFILE-NOTFOUND" CACHE FILEPATH "Point it to the export file from a native build")
-    INCLUDE(${IMPORT_EXECUTABLES})
-ENDIF(CMAKE_CROSSCOMPILING)
-
-IF(NOT CMAKE_CROSSCOMPILING)
-    ADD_EXECUTABLE(bbasm bba/main.cc)
-    target_link_libraries(bbasm LINK_PUBLIC ${Boost_PROGRAM_OPTIONS_LIBRARY} ${Boost_FILESYSTEM_LIBRARY} ${Boost_SYSTEM_LIBRARY})
-ENDIF(NOT CMAKE_CROSSCOMPILING)
-
-IF(NOT CMAKE_CROSSCOMPILING)
-    EXPORT(TARGETS bbasm FILE ${CMAKE_BINARY_DIR}/ImportExecutables.cmake )
-ENDIF(NOT CMAKE_CROSSCOMPILING)
-
-include(TestBigEndian)
-TEST_BIG_ENDIAN(IS_BIG_ENDIAN)
-if(IS_BIG_ENDIAN)
-	set(BBASM_ENDIAN_FLAG "--be")
-else()
-	set(BBASM_ENDIAN_FLAG "--le")
-endif()