From 8699e96609d4449fa1c7704a292a76bbbb5d6bb8 Mon Sep 17 00:00:00 2001
From: Michele Caini <michele.caini@gmail.com>
Date: Sat, 23 Oct 2021 12:09:44 +0200
Subject: [PATCH] build_system: * ENTT_USE_LIBCPP default is OFF * added
 ENTT_INCLUDE_HEADERS to make adding headers to the EnTT target optional *
 slightly better message handling

---
 CMakeLists.txt | 180 ++++++++++++++++++++++++++-----------------------
 1 file changed, 94 insertions(+), 86 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a78c9b9a9..113794f90 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -42,37 +42,41 @@ message(VERBOSE "* ${PROJECT_NAME} v${PROJECT_VERSION} (${CMAKE_BUILD_TYPE})")
 message(VERBOSE "* Copyright (c) 2017-2021 Michele Caini <michele.caini@gmail.com>")
 message(VERBOSE "*")
 
-option(ENTT_USE_LIBCPP "Use libc++ by adding -stdlib=libc++ flag if availbale." ON)
+option(ENTT_USE_LIBCPP "Use libc++ by adding -stdlib=libc++ flag if availbale." OFF)
 option(ENTT_USE_SANITIZER "Enable sanitizers by adding -fsanitize=address -fno-omit-frame-pointer -fsanitize=undefined flags if availbale." OFF)
 
 #
 # Compiler stuff
 #
 
-if(NOT WIN32 AND ENTT_USE_LIBCPP)
-    include(CheckCXXSourceCompiles)
-    include(CMakePushCheckState)
+if(ENTT_USE_LIBCPP)
+    if(NOT WIN32)
+        include(CheckCXXSourceCompiles)
+        include(CMakePushCheckState)
 
-    cmake_push_check_state()
+        cmake_push_check_state()
 
-    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -stdlib=libc++")
+        set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -stdlib=libc++")
 
-    check_cxx_source_compiles("
-        #include<type_traits>
-        int main() { return std::is_same_v<int, char>; }
-    " ENTT_HAS_LIBCPP)
+        check_cxx_source_compiles("
+            #include<type_traits>
+            int main() { return std::is_same_v<int, char>; }
+        " ENTT_HAS_LIBCPP)
+
+        cmake_pop_check_state()
+    endif()
 
     if(NOT ENTT_HAS_LIBCPP)
         message(VERBOSE "The option ENTT_USE_LIBCPP is set but libc++ is not available. The flag will not be added to the target.")
     endif()
-
-    cmake_pop_check_state()
 endif()
 
 if(ENTT_USE_SANITIZER)
     if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU")
         set(ENTT_HAS_SANITIZER TRUE CACHE INTERNAL "")
-    else()
+    endif()
+
+    if(NOT ENTT_HAS_SANITIZER)
         message(VERBOSE "The option ENTT_USE_SANITIZER is set but sanitizer support is not available. The flags will not be added to the target.")
     endif()
 endif()
@@ -81,82 +85,13 @@ endif()
 # Add EnTT target
 #
 
+option(ENTT_INCLUDE_HEADERS "Add all EnTT headers to the EnTT target." OFF)
+
 include(GNUInstallDirs)
 
 add_library(EnTT INTERFACE)
 add_library(EnTT::EnTT ALIAS EnTT)
 
-target_sources(
-    EnTT
-    INTERFACE
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/config/config.h>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/config/version.h>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/container/dense_hash_map.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/container/fwd.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/algorithm.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/any.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/attribute.h>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/compressed_pair.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/enum.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/family.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/fwd.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/hashed_string.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/ident.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/memory.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/monostate.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/tuple.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/type_info.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/type_traits.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/utility.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/component.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/entity.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/fwd.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/group.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/handle.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/helper.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/observer.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/organizer.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/poly_storage.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/registry.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/runtime_view.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/snapshot.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/sparse_set.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/storage.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/utility.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/view.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/locator/locator.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/adl_pointer.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/container.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/ctx.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/factory.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/fwd.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/meta.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/node.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/pointer.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/policy.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/range.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/resolve.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/template.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/type_traits.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/utility.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/platform/android-ndk-r17.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/poly/fwd.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/poly/poly.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/process/process.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/process/scheduler.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/resource/cache.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/resource/fwd.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/resource/handle.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/resource/loader.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/delegate.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/dispatcher.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/emitter.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/fwd.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/sigh.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entt.hpp>
-        $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/fwd.hpp>
-)
-
 target_include_directories(
     EnTT
     INTERFACE
@@ -164,6 +99,81 @@ target_include_directories(
         $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
 )
 
+target_compile_features(EnTT INTERFACE cxx_std_17)
+
+if(ENTT_INCLUDE_HEADERS)
+    target_sources(
+        EnTT
+        INTERFACE
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/config/config.h>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/config/version.h>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/container/dense_hash_map.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/container/fwd.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/algorithm.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/any.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/attribute.h>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/compressed_pair.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/enum.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/family.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/fwd.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/hashed_string.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/ident.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/memory.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/monostate.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/tuple.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/type_info.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/type_traits.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/core/utility.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/component.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/entity.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/fwd.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/group.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/handle.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/helper.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/observer.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/organizer.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/poly_storage.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/registry.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/runtime_view.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/snapshot.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/sparse_set.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/storage.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/utility.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entity/view.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/locator/locator.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/adl_pointer.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/container.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/ctx.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/factory.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/fwd.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/meta.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/node.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/pointer.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/policy.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/range.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/resolve.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/template.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/type_traits.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/meta/utility.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/platform/android-ndk-r17.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/poly/fwd.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/poly/poly.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/process/process.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/process/scheduler.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/resource/cache.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/resource/fwd.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/resource/handle.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/resource/loader.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/delegate.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/dispatcher.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/emitter.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/fwd.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/signal/sigh.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/entt.hpp>
+            $<BUILD_INTERFACE:${EnTT_SOURCE_DIR}/src/entt/fwd.hpp>
+    )
+endif()
+
 if(ENTT_HAS_SANITIZER)
     target_compile_options(EnTT INTERFACE $<$<CONFIG:Debug>:-fsanitize=address -fno-omit-frame-pointer -fsanitize=undefined>)
     target_link_libraries(EnTT INTERFACE $<$<CONFIG:Debug>:-fsanitize=address -fno-omit-frame-pointer -fsanitize=undefined>)
@@ -173,8 +183,6 @@ if(ENTT_HAS_LIBCPP)
     target_compile_options(EnTT BEFORE INTERFACE -stdlib=libc++)
 endif()
 
-target_compile_features(EnTT INTERFACE cxx_std_17)
-
 #
 # Install pkg-config file
 #