cmake: use a library target to avoid recompilation

Edward Thomson · Edward Thomson · commit e352ccb0d6af · 2016-10-01T19:26:20.000-05:00
Instead of listing the sources separately for the git2 target and the libgit2_clar target, create an "object library" target (for more information, see at https://cmake.org/Wiki/CMake/Tutorials/Object_Library). The object library will then be used to link both the git2 library target and the libgit2_clar target instead of having to compile all the source twice.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -595,8 +595,11 @@ ELSE()
 	MESSAGE(FATAL_ERROR "Unsupported architecture (CMAKE_SIZEOF_VOID_P is unset)")
 ENDIF()
 
-# Compile and link libgit2
-ADD_LIBRARY(git2 ${SRC_H} ${SRC_GIT2} ${SRC_OS} ${SRC_ZLIB} ${SRC_HTTP} ${SRC_REGEX} ${SRC_SSH} ${SRC_SHA1} ${WIN_RC})
+# Compile and link a static version of libgit2; we will use this to link both
+# a shared library (unless disabled) and clar.
+ADD_LIBRARY(git2-objects OBJECT ${SRC_H} ${SRC_GIT2} ${SRC_OS} ${SRC_ZLIB} ${SRC_HTTP} ${SRC_REGEX} ${SRC_SSH} ${SRC_SHA1})
+
+ADD_LIBRARY(git2 ${WIN_RC} $<TARGET_OBJECTS:git2-objects>)
 TARGET_LINK_LIBRARIES(git2 ${SECURITY_DIRS})
 TARGET_LINK_LIBRARIES(git2 ${COREFOUNDATION_DIRS})
 TARGET_LINK_LIBRARIES(git2 ${SSL_LIBRARIES})
@@ -614,8 +617,8 @@ ENDIF()
 IDE_SPLIT_SOURCES(git2)
 
 IF (SONAME)
-	SET_TARGET_PROPERTIES(git2 PROPERTIES VERSION ${LIBGIT2_VERSION_STRING})
-	SET_TARGET_PROPERTIES(git2 PROPERTIES SOVERSION ${LIBGIT2_SOVERSION})
+#	SET_TARGET_PROPERTIES(git2 PROPERTIES VERSION ${LIBGIT2_VERSION_STRING})
+#	SET_TARGET_PROPERTIES(git2 PROPERTIES SOVERSION ${LIBGIT2_SOVERSION})
 	IF (LIBGIT2_FILENAME)
 		ADD_DEFINITIONS(-DLIBGIT2_FILENAME=\"${LIBGIT2_FILENAME}\")
 		SET_TARGET_PROPERTIES(git2 PROPERTIES OUTPUT_NAME ${LIBGIT2_FILENAME})
@@ -633,11 +636,11 @@ IF (MSVC_IDE)
 ENDIF ()
 
 # Install
-INSTALL(TARGETS git2
-	RUNTIME DESTINATION ${BIN_INSTALL_DIR}
-	LIBRARY DESTINATION ${LIB_INSTALL_DIR}
-	ARCHIVE DESTINATION ${LIB_INSTALL_DIR}
-)
+#INSTALL(TARGETS git2
+#	RUNTIME DESTINATION ${BIN_INSTALL_DIR}
+#	LIBRARY DESTINATION ${LIB_INSTALL_DIR}
+#	ARCHIVE DESTINATION ${LIB_INSTALL_DIR}
+#)
 INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/libgit2.pc DESTINATION ${LIB_INSTALL_DIR}/pkgconfig )
 INSTALL(DIRECTORY include/git2 DESTINATION ${INCLUDE_INSTALL_DIR} )
 INSTALL(FILES include/git2.h DESTINATION ${INCLUDE_INSTALL_DIR} )
@@ -673,7 +676,7 @@ IF (BUILD_CLAR)
 		${CLAR_PATH}/clar.c
 		PROPERTIES OBJECT_DEPENDS ${CLAR_PATH}/clar.suite)
 
-	ADD_EXECUTABLE(libgit2_clar ${SRC_H} ${SRC_GIT2} ${SRC_OS} ${SRC_CLAR} ${SRC_TEST} ${SRC_ZLIB} ${SRC_HTTP} ${SRC_REGEX} ${SRC_SSH} ${SRC_SHA1})
+	ADD_EXECUTABLE(libgit2_clar ${SRC_CLAR} ${SRC_TEST} $<TARGET_OBJECTS:git2-objects>)
 
 	TARGET_LINK_LIBRARIES(libgit2_clar ${COREFOUNDATION_DIRS})
 	TARGET_LINK_LIBRARIES(libgit2_clar ${SECURITY_DIRS})
