CMake: New option BUILD_SHARED_AND_STATIC_LIBS

CMakeLists.txt

@@ -103,7 +103,17 @@ set(CJSON_LIB cjson)
 file(GLOB HEADERS cJSON.h)
 set(SOURCES cJSON.c)
 
-add_library("${CJSON_LIB}" "${HEADERS}" "${SOURCES}")
+option(BUILD_SHARED_AND_STATIC_LIBS "Build both shared and static libraries" Off)
+
+if (NOT BUILD_SHARED_AND_STATIC_LIBS)
+    add_library("${CJSON_LIB}" "${HEADERS}" "${SOURCES}")
+else()
+    # See https://cmake.org/Wiki/CMake_FAQ#How_do_I_make_my_shared_and_static_libraries_have_the_same_root_name.2C_but_different_suffixes.3F
+    add_library("${CJSON_LIB}" SHARED "${HEADERS}" "${SOURCES}")
+    add_library("${CJSON_LIB}-static" STATIC "${HEADERS}" "${SOURCES}")
+    set_target_properties("${CJSON_LIB}-static" PROPERTIES OUTPUT_NAME "${CJSON_LIB}")
+    set_target_properties("${CJSON_LIB}-static" PROPERTIES PREFIX "lib")
+endif()
 if (NOT WIN32)
     target_link_libraries("${CJSON_LIB}" m)
 endif()
@@ -114,6 +124,9 @@ configure_file("${CMAKE_CURRENT_SOURCE_DIR}/library_config/libcjson.pc.in"
 install(FILES cJSON.h DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/cjson")
 install (FILES "${CMAKE_CURRENT_BINARY_DIR}/libcjson.pc" DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
 install(TARGETS "${CJSON_LIB}" DESTINATION "${CMAKE_INSTALL_LIBDIR}" EXPORT "${CJSON_LIB}")
+if (BUILD_SHARED_AND_STATIC_LIBS)
+    install(TARGETS "${CJSON_LIB}-static" DESTINATION "${CMAKE_INSTALL_LIBDIR}")
+endif()
 if(ENABLE_TARGET_EXPORT)
     # export library information for CMake projects
     install(EXPORT "${CJSON_LIB}" DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/cJSON")
@@ -132,13 +145,25 @@ if(ENABLE_CJSON_UTILS)
     file(GLOB HEADERS_UTILS cJSON_Utils.h)
     set(SOURCES_UTILS cJSON_Utils.c)
 
-    add_library("${CJSON_UTILS_LIB}" "${HEADERS_UTILS}" "${SOURCES_UTILS}")
-    target_link_libraries("${CJSON_UTILS_LIB}" "${CJSON_LIB}")
+    if (NOT BUILD_SHARED_AND_STATIC_LIBS)
+        add_library("${CJSON_UTILS_LIB}" "${HEADERS_UTILS}" "${SOURCES_UTILS}")
+        target_link_libraries("${CJSON_UTILS_LIB}" "${CJSON_LIB}")
+    else()
+        add_library("${CJSON_UTILS_LIB}" SHARED "${HEADERS_UTILS}" "${SOURCES_UTILS}")
+        target_link_libraries("${CJSON_UTILS_LIB}" "${CJSON_LIB}")
+        add_library("${CJSON_UTILS_LIB}-static" STATIC "${HEADERS_UTILS}" "${SOURCES_UTILS}")
+        target_link_libraries("${CJSON_UTILS_LIB}-static" "${CJSON_LIB}-static")
+        set_target_properties("${CJSON_UTILS_LIB}-static" PROPERTIES OUTPUT_NAME "${CJSON_UTILS_LIB}")
+        set_target_properties("${CJSON_UTILS_LIB}-static" PROPERTIES PREFIX "lib")
+    endif()
 
     configure_file("${CMAKE_CURRENT_SOURCE_DIR}/library_config/libcjson_utils.pc.in"
         "${CMAKE_CURRENT_BINARY_DIR}/libcjson_utils.pc" @ONLY)
 
     install(TARGETS "${CJSON_UTILS_LIB}" DESTINATION "${CMAKE_INSTALL_LIBDIR}" EXPORT "${CJSON_UTILS_LIB}")
+    if (BUILD_SHARED_AND_STATIC_LIBS)
+        install(TARGETS "${CJSON_UTILS_LIB}-static" DESTINATION "${CMAKE_INSTALL_LIBDIR}")
+    endif()
     install(FILES cJSON_Utils.h DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/cjson")
     install (FILES "${CMAKE_CURRENT_BINARY_DIR}/libcjson_utils.pc" DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
     if(ENABLE_TARGET_EXPORT)

README.md

@@ -89,6 +89,7 @@ You can change the build process with a list of different options that you can p
 * `-DENABLE_VALGRIND=On`: Run tests with [valgrind](http://valgrind.org). (off by default)
 * `-DENABLE_SANITIZERS=On`: Compile cJSON with [AddressSanitizer](https://github.com/google/sanitizers/wiki/AddressSanitizer) and [UndefinedBehaviorSanitizer](https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html) enabled (if possible). (off by default)
 * `-DBUILD_SHARED_LIBS=On`: Build the shared libraries. (on by default)
+* `-DBUILD_SHARED_AND_STATIC_LIBS=On`: Build both shared and static libraries. (off by default)
 * `-DCMAKE_INSTALL_PREFIX=/usr`: Set a prefix for the installation.
 
 If you are packaging cJSON for a distribution of Linux, you would probably take these steps for example: