Adding improvements to ROOT

examples/root-dict/CMakeLists.txt

@@ -1,29 +1,36 @@
 
 ## [main]
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.4)
 
 project(RootDictExample LANGUAGES CXX)
 
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+set(CMAKE_PLATFORM_INDEPENDENT_CODE ON)
+
+find_package(Threads)
+
 find_package(ROOT CONFIG REQUIRED)
 include("${ROOT_DIR}/modules/RootNewMacros.cmake")
 
-message(STATUS "Found ROOT: ${ROOT_VERSION} at ${ROOT_DIR}")
-
-separate_arguments(ROOT_CXX_FLAGS)
-
+# We will set the flags ourselves
 set_target_properties(ROOT::Core PROPERTIES
-    INTERFACE_INCLUDE_DIRECTORIES "${ROOT_INCLUDE_DIRS}"
-    INTERFACE_COMPILE_OPTIONS "${ROOT_CXX_FLAGS}"
-    )
+    INTERFACE_INCLUDE_DIRECTORIES "${ROOT_INCLUDE_DIRS}")
 
 include_directories(ROOT_BUG)
 root_generate_dictionary(G__DictExample DictExample.h LINKDEF DictLinkDef.h)
 
 add_library(DictExample SHARED DictExample.cxx DictExample.h G__DictExample.cxx)
-target_link_libraries(DictExample PUBLIC ROOT::Core)
+target_link_libraries(DictExample PUBLIC ROOT::Core Threads::Threads)
 
 ## [main]
 
+message(STATUS "Found ROOT: ${ROOT_VERSION} at ${ROOT_DIR}")
+message(STATUS "Original flags: ${ROOT_CXX_FLAGS}")
+message(STATUS "Original definitions: ${ROOT_DEFINITIONS}")
+message(STATUS "Original exe flags: ${ROOT_EXE_LINKER_FLAGS}")
+
 enable_testing()
 add_test(NAME RootDictExample
     WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"

examples/root-dict/README.md

@@ -1,6 +1,8 @@
 # Dictionary Example
 
-This is an example of building a module that includes a dictionary in CMake.
+This is an example of building a module that includes a dictionary in CMake. Instead of using the
+ROOT suggested flags, we will manually add threading via `find_package`, which is the only
+important flag in the list on most systems.
 
 #### examples/root-dict/CMakeLists.txt
 [import:'main', lang:'cmake'](CMakeLists.txt)

examples/root-simple-3.11/CMakeLists.txt

@@ -5,23 +5,23 @@ cmake_minimum_required(VERSION 3.11)
 project(RootSimpleExample311 LANGUAGES CXX)
 
 find_package(ROOT CONFIG REQUIRED)
-message(STATUS "Found ROOT: ${ROOT_VERSION} at ${ROOT_DIR}")
-
-separate_arguments(ROOT_CXX_FLAGS)
-separate_arguments(ROOT_DEFINITIONS)
-message(STATUS "ROOT_DEFINITIONS ${ROOT_DEFINITIONS}")
-
-# This is required on if there is more than one flag (like on macOS)
-# and this also fixes a bug in the linker flags
-string(REPLACE "-L " "-L" ROOT_EXE_LINKER_FLAGS "${ROOT_EXE_LINKER_FLAGS}")
-separate_arguments(ROOT_EXE_LINKER_FLAGS)
 
 ## [modern_fix]
 target_include_directories(ROOT::Core INTERFACE "${ROOT_INCLUDE_DIRS}")
 
 add_library(ROOT::Flags_CXX IMPORTED INTERFACE)
+
+separate_arguments(ROOT_CXX_FLAGS)
 target_compile_options(ROOT::Flags_CXX INTERFACE ${ROOT_CXX_FLAGS})
+
+separate_arguments(ROOT_DEFINITIONS)
 target_compile_definitions(ROOT::Flags_CXX INTERFACE ${ROOT_DEFINITIONS})
+
+# This fixes a bug in the linker flags
+string(REPLACE "-L " "-L" ROOT_EXE_LINKER_FLAGS "${ROOT_EXE_LINKER_FLAGS}")
+separate_arguments(ROOT_EXE_LINKER_FLAGS)
+# Stuck into using old property method due to separate -L and -l arguments
+# (A full path to -l is better!)
 set_property(TARGET ROOT::Flags_CXX PROPERTY
     INTERFACE_LINK_LIBRARIES ${ROOT_EXE_LINKER_FLAGS})
 ## [modern_fix]

examples/root-simple/CMakeLists.txt

@@ -8,8 +8,6 @@ project(RootSimpleExample LANGUAGES CXX)
 find_package(ROOT CONFIG REQUIRED)
 ## [find_package]
 
-message(STATUS "Found ROOT: ${ROOT_VERSION} at ${ROOT_DIR}")
-
 # ROOT targets are missing includes and flags
 ## [setup_includes]
 set_property(TARGET ROOT::Core PROPERTY
@@ -17,20 +15,24 @@ set_property(TARGET ROOT::Core PROPERTY
 ## [setup_includes]
 
 ## [setup_flags]
+add_library(ROOT::Flags_CXX IMPORTED INTERFACE)
+
 # Fix for ROOT_CXX_FLAGS not actually being a CMake list
 separate_arguments(ROOT_CXX_FLAGS)
-separate_arguments(ROOT_DEFINITIONS)
-
-# This is required on if there is more than one flag (like on macOS)
-# and this also fixes a bug in the linker flags
-string(REPLACE "-L " "-L" ROOT_EXE_LINKER_FLAGS "${ROOT_EXE_LINKER_FLAGS}")
-separate_arguments(ROOT_EXE_LINKER_FLAGS)
-
-add_library(ROOT::Flags_CXX IMPORTED INTERFACE)
 set_property(TARGET ROOT::Flags_CXX APPEND PROPERTY
     INTERFACE_COMPILE_OPTIONS ${ROOT_CXX_FLAGS})
-set_property(TARGET ROOT::Flags_CXX APPEND PROPERTY
-    INTERFACE_COMPILE_DEFINITIONS ${ROOT_DEFINITIONS})
+
+# Add definitions
+separate_arguments(ROOT_DEFINITIONS)
+foreach(_flag ${ROOT_EXE_LINKER_FLAG_LIST})
+    # Remove -D or /D if present
+    string(REGEX REPLACE [=[^[-//]D]=] "" _flag ${_flag})
+    set_property(TARGET ROOT::Flags APPEND PROPERTY INTERFACE_LINK_LIBRARIES ${_flag})
+endforeach()
+
+# This also fixes a bug in the linker flags
+string(REPLACE "-L " "-L" ROOT_EXE_LINKER_FLAGS "${ROOT_EXE_LINKER_FLAGS}")
+separate_arguments(ROOT_EXE_LINKER_FLAGS)
 set_property(TARGET ROOT::Flags_CXX APPEND PROPERTY
     INTERFACE_LINK_LIBRARIES ${ROOT_EXE_LINKER_FLAGS})
 ## [setup_flags]

examples/root-usefile/CMakeLists.txt

@@ -5,7 +5,6 @@ cmake_minimum_required(VERSION 3.1)
 project(RootUseFileExample LANGUAGES CXX)
 
 find_package(ROOT CONFIG REQUIRED)
-message(STATUS "Found ROOT: ${ROOT_VERSION} at ${ROOT_DIR}")
 
 include("${ROOT_USE_FILE}")