Bump CMake version, use target_xyz functions instead of global add_xyz

Author: MazTheMan

CMakeLists.txt

@@ -12,8 +12,8 @@
 # CMake versions greater than the JSONCPP_NEWEST_VALIDATED_POLICIES_VERSION policies will
 # continue to generate policy warnings "CMake Warning (dev)...Policy CMP0XXX is not set:"
 #
-set(JSONCPP_OLDEST_VALIDATED_POLICIES_VERSION "3.8.0")
-set(JSONCPP_NEWEST_VALIDATED_POLICIES_VERSION "3.13.2")
+set(JSONCPP_OLDEST_VALIDATED_POLICIES_VERSION "3.21..")
+set(JSONCPP_NEWEST_VALIDATED_POLICIES_VERSION "3.29")
 cmake_minimum_required(VERSION ${JSONCPP_OLDEST_VALIDATED_POLICIES_VERSION})
 if("${CMAKE_VERSION}" VERSION_LESS "${JSONCPP_NEWEST_VALIDATED_POLICIES_VERSION}")
     #Set and use the newest available cmake policies that are validated to work
@@ -40,12 +40,6 @@ foreach(pold "") # Currently Empty
     endif()
 endforeach()
 
-# Build the library with C++11 standard support, independent from other including
-# software which may use a different CXX_STANDARD or CMAKE_CXX_STANDARD.
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_EXTENSIONS OFF)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-
 # Ensure that CMAKE_BUILD_TYPE has a value specified for single configuration generators.
 if(NOT DEFINED CMAKE_BUILD_TYPE AND NOT DEFINED CMAKE_CONFIGURATION_TYPES)
     set(CMAKE_BUILD_TYPE Release CACHE STRING
@@ -75,6 +69,15 @@ project(jsoncpp
         VERSION 1.9.5 # <major>[.<minor>[.<patch>[.<tweak>]]]
         LANGUAGES CXX)
 
+
+if (PROJECT_IS_TOP_LEVEL)
+    # Build the library with C++11 standard support, independent from other including
+    # software which may use a different CXX_STANDARD or CMAKE_CXX_STANDARD.
+    set(CMAKE_CXX_STANDARD 11)
+    set(CMAKE_CXX_EXTENSIONS OFF)
+    set(CMAKE_CXX_STANDARD_REQUIRED ON)
+endif()
+
 message(STATUS "JsonCpp Version: ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT_VERSION_PATCH}")
 set(PROJECT_SOVERSION 25)
 
@@ -105,6 +108,8 @@ endif()
 
 set(JSONCPP_USE_SECURE_MEMORY "0" CACHE STRING "-D...=1 to use memory-wiping allocator for STL")
 
+add_library(project_options INTERFACE)
+
 configure_file("${PROJECT_SOURCE_DIR}/version.in"
     "${PROJECT_BINARY_DIR}/version"
     NEWLINE_STYLE UNIX)
@@ -113,53 +118,53 @@ macro(use_compilation_warning_as_error)
     if(MSVC)
         # Only enabled in debug because some old versions of VS STL generate
         # warnings when compiled in release configuration.
-        add_compile_options($<$<CONFIG:Debug>:/WX>)
+        target_compile_options(project_options INTERFACE $<$<CONFIG:Debug>:/WX>)
     elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-        add_compile_options(-Werror)
+        target_compile_options(project_options INTERFACE -Werror)
         if(JSONCPP_WITH_STRICT_ISO)
-            add_compile_options(-pedantic-errors)
+            target_compile_options(project_options INTETFACE -pedantic-errors)
         endif()
     endif()
 endmacro()
 
 # Include our configuration header
-include_directories(${jsoncpp_SOURCE_DIR}/include)
+target_include_directories(project_options INTERFACE ${jsoncpp_SOURCE_DIR}/include)
 
 if(MSVC)
     # Only enabled in debug because some old versions of VS STL generate
     # unreachable code warning when compiled in release configuration.
-    add_compile_options($<$<CONFIG:Debug>:/W4>)
+    target_compile_options(project_options INTERFACE $<$<CONFIG:Debug>:/W4>)
     if (JSONCPP_STATIC_WINDOWS_RUNTIME)
         set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
     endif()
 endif()
 
 if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     # using regular Clang or AppleClang
-    add_compile_options(-Wall -Wconversion -Wshadow)
+    target_compile_options(project_options INTERFACE -Wall -Wconversion -Wshadow)
 
     if(JSONCPP_WITH_WARNING_AS_ERROR)
-        add_compile_options(-Werror=conversion -Werror=sign-compare)
+        target_compile_options(project_options INTERFACE  -Werror=conversion -Werror=sign-compare)
     endif()
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     # using GCC
-    add_compile_options(-Wall -Wconversion -Wshadow -Wextra)
+    target_compile_options(project_options INTERFACE  -Wall -Wconversion -Wshadow -Wextra)
     # not yet ready for -Wsign-conversion
 
     if(JSONCPP_WITH_STRICT_ISO)
-        add_compile_options(-Wpedantic)
+        target_compile_options(project_options INTERFACE -Wpedantic)
     endif()
     if(JSONCPP_WITH_WARNING_AS_ERROR)
-        add_compile_options(-Werror=conversion)
+        target_compile_options(project_options INTERFACE -Werror=conversion)
     endif()
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
     # using Intel compiler
-    add_compile_options(-Wall -Wconversion -Wshadow -Wextra)
+    target_compile_options(project_options INTERFACE -Wall -Wconversion -Wshadow -Wextra)
 
     if(JSONCPP_WITH_WARNING_AS_ERROR)
-        add_compile_options(-Werror=conversion)
+        target_compile_options(project_options INTERFACE -Werror=conversion)
     elseif(JSONCPP_WITH_STRICT_ISO)
-        add_compile_options(-Wpedantic)
+        target_compile_options(project_options INTERFACE -Wpedantic)
     endif()
 endif()
 

example/CMakeLists.txt

@@ -5,21 +5,27 @@ set(EXAMPLES
     stringWrite
     streamWrite
 )
-add_definitions(-D_GLIBCXX_USE_CXX11_ABI)
 
-if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-    add_compile_options(-Wall -Wextra)
-elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
-    add_definitions(
-        -D_SCL_SECURE_NO_WARNINGS
-        -D_CRT_SECURE_NO_WARNINGS
-        -D_WIN32_WINNT=0x601
-        -D_WINSOCK_DEPRECATED_NO_WARNINGS
-    )
+macro(add_example_options target)
+
+    target_compile_definitions(${target} -D_GLIBCXX_USE_CXX11_ABI)
+
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+        target_compile_options(${target} PRIVATE -Wall -Wextra)
+    elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+        target_compile_definitions(${target}
+            PRIVATE
+            -D_SCL_SECURE_NO_WARNINGS
+            -D_CRT_SECURE_NO_WARNINGS
+            -D_WIN32_WINNT=0x601
+            -D_WINSOCK_DEPRECATED_NO_WARNINGS
+        )
+    endif()
 endif()
 
 foreach(example ${EXAMPLES})
     add_executable(${example} ${example}/${example}.cpp)
+    add_example_options(${example})
     target_include_directories(${example} PUBLIC ${CMAKE_SOURCE_DIR}/include)
     target_link_libraries(${example} jsoncpp_lib)
 endforeach()

src/jsontestrunner/CMakeLists.txt

@@ -15,7 +15,7 @@ add_executable(jsontestrunner_exe
 
 if(BUILD_SHARED_LIBS)
     if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
-        add_compile_definitions( JSON_DLL )
+        target_compile_definitions(jsontestrunner_exe PUBLIC JSON_DLL )
     else()
         add_definitions(-DJSON_DLL)
     endif()

src/lib_json/CMakeLists.txt

@@ -1,13 +1,16 @@
+add_library(jsonlib_options INTERFACE)
 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 4.1.2)
     #-Werror=* was introduced -after- GCC 4.1.2
-    add_compile_options("-Werror=strict-aliasing")
+    target_compile_options(jsonlib_options INTERFACE "-Werror=strict-aliasing")
 endif()
 
 include(CheckIncludeFileCXX)
 include(CheckTypeSize)
 include(CheckStructHasMember)
 include(CheckCXXSymbolExists)
 
+# might have to do this: list(APPEND CMAKE_REQUIRED_INCLUDES ${ASIO_PATH}) <-- with some path that is missing...?
+
 check_include_file_cxx(clocale HAVE_CLOCALE)
 check_cxx_symbol_exists(localeconv clocale HAVE_LOCALECONV)
 
@@ -19,7 +22,7 @@ check_struct_has_member(lconv decimal_point clocale HAVE_DECIMAL_POINT LANGUAGE
 if(NOT (HAVE_CLOCALE AND HAVE_LCONV_SIZE AND HAVE_DECIMAL_POINT AND HAVE_LOCALECONV))
     message(WARNING "Locale functionality is not supported")
     if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
-        add_compile_definitions(JSONCPP_NO_LOCALE_SUPPORT)
+        target_compile_definitions(jsonlib_options PUBLIC JSONCPP_NO_LOCALE_SUPPORT)
     else()
         add_definitions(-DJSONCPP_NO_LOCALE_SUPPORT)
     endif()
@@ -107,14 +110,13 @@ list(APPEND REQUIRED_FEATURES
 
 
 if(BUILD_SHARED_LIBS)
+    set(SHARED_LIB ${PROJECT_NAME}_lib)
+    add_library(${SHARED_LIB} SHARED ${PUBLIC_HEADERS} ${JSONCPP_SOURCES})
     if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
-        add_compile_definitions(JSON_DLL_BUILD)
+        target_compile_definitions(${SHARED_LIB} PUBLIC JSON_DLL_BUILD)
     else()
         add_definitions(-DJSON_DLL_BUILD)
     endif()
-
-    set(SHARED_LIB ${PROJECT_NAME}_lib)
-    add_library(${SHARED_LIB} SHARED ${PUBLIC_HEADERS} ${JSONCPP_SOURCES})
     set_target_properties(${SHARED_LIB} PROPERTIES
         OUTPUT_NAME jsoncpp
         VERSION ${PROJECT_VERSION}
@@ -128,6 +130,10 @@ if(BUILD_SHARED_LIBS)
     endif()
 
     target_compile_features(${SHARED_LIB} PUBLIC ${REQUIRED_FEATURES})
+    target_link_libraries(${SHARED_LIB} PUBLIC
+        $<BUILD_INTERFACE:project_options>
+        $<BUILD_INTERFACE:jsonlib_options>
+    )
 
     target_include_directories(${SHARED_LIB} PUBLIC
         $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
@@ -162,6 +168,10 @@ if(BUILD_STATIC_LIBS)
     endif()
 
     target_compile_features(${STATIC_LIB} PUBLIC ${REQUIRED_FEATURES})
+    target_link_libraries(${STATIC_LIB} PUBLIC
+        $<BUILD_INTERFACE:project_options>
+        $<BUILD_INTERFACE:jsonlib_options>
+    )
 
     target_include_directories(${STATIC_LIB} PUBLIC
         $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
@@ -189,6 +199,10 @@ if(BUILD_OBJECT_LIBS)
     endif()
 
     target_compile_features(${OBJECT_LIB} PUBLIC ${REQUIRED_FEATURES})
+    target_link_libraries(${OBJECT_LIB} PUBLIC
+        $<BUILD_INTERFACE:project_options>
+        $<BUILD_INTERFACE:jsonlib_options>
+    )
 
     target_include_directories(${OBJECT_LIB} PUBLIC
         $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>

src/test_lib_json/CMakeLists.txt

@@ -11,13 +11,15 @@ add_executable(jsoncpp_test
 
 if(BUILD_SHARED_LIBS)
     if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
-        add_compile_definitions( JSON_DLL )
+        target_compile_definitions(jsoncpp_test PRIVATE JSON_DLL )
     else()
-        add_definitions( -DJSON_DLL )
+        target_compile_definitions(jsoncpp_test PRIVATE -DJSON_DLL )
     endif()
-    target_link_libraries(jsoncpp_test jsoncpp_lib)
-else()
-    target_link_libraries(jsoncpp_test jsoncpp_static)
+    target_link_libraries(jsoncpp_test jsoncpp_lib
+        $<BUILD_INTERFACE:project_options>
+    )
+    else()
+    target_link_libraries(jsoncpp_test jsoncpp_static $<BUILD_INTERFACE:project_options>)
 endif()
 
 # another way to solve issue #90