Fix issues with C++ enum reflection without meta addon

SanderMertens · SanderMertens · commit 30f8d96294c3 · 2025-02-07T19:13:02.000-08:00
diff --git a/distr/flecs.c b/distr/flecs.c
@@ -21287,6 +21287,10 @@ void ecs_cpp_enum_init(
     world = flecs_suspend_readonly(world, &readonly_state);
     ecs_set(world, id, EcsEnum, { .underlying_type = underlying_type });
     flecs_resume_readonly(world, &readonly_state);
+#else
+    /* Make sure that enums still behave the same even without meta */
+    ecs_add_id(world, id, EcsExclusive);
+    ecs_add_id(world, id, EcsOneOf);
 #endif
 }
 
diff --git a/distr/flecs.h b/distr/flecs.h
@@ -33312,6 +33312,20 @@ inline void world::init_builtin_components() {
     this->component<Identifier>();
     this->component<Poly>();
 
+    /* If meta is not defined and we're using enum reflection, make sure that
+     * primitive types are registered. This makes sure we can set components of
+     * underlying_type_t<E> when registering constants. */
+#   if !defined(FLECS_META) && !defined(FLECS_CPP_NO_ENUM_REFLECTION)
+    this->component<uint8_t>("flecs::meta::u8");
+    this->component<uint16_t>("flecs::meta::u16");
+    this->component<uint32_t>("flecs::meta::u32");
+    this->component<uint64_t>("flecs::meta::u64");
+    this->component<int8_t>("flecs::meta::i8");
+    this->component<int16_t>("flecs::meta::i16");
+    this->component<int32_t>("flecs::meta::i32");
+    this->component<int64_t>("flecs::meta::i64");
+#   endif
+
 #   ifdef FLECS_SYSTEM
     _::system_init(*this);
 #   endif
diff --git a/include/flecs/addons/cpp/impl/world.hpp b/include/flecs/addons/cpp/impl/world.hpp
@@ -13,6 +13,20 @@ inline void world::init_builtin_components() {
     this->component<Identifier>();
     this->component<Poly>();
 
+    /* If meta is not defined and we're using enum reflection, make sure that
+     * primitive types are registered. This makes sure we can set components of
+     * underlying_type_t<E> when registering constants. */
+#   if !defined(FLECS_META) && !defined(FLECS_CPP_NO_ENUM_REFLECTION)
+    this->component<uint8_t>("flecs::meta::u8");
+    this->component<uint16_t>("flecs::meta::u16");
+    this->component<uint32_t>("flecs::meta::u32");
+    this->component<uint64_t>("flecs::meta::u64");
+    this->component<int8_t>("flecs::meta::i8");
+    this->component<int16_t>("flecs::meta::i16");
+    this->component<int32_t>("flecs::meta::i32");
+    this->component<int64_t>("flecs::meta::i64");
+#   endif
+
 #   ifdef FLECS_SYSTEM
     _::system_init(*this);
 #   endif
diff --git a/src/addons/flecs_cpp.c b/src/addons/flecs_cpp.c
@@ -382,6 +382,10 @@ void ecs_cpp_enum_init(
     world = flecs_suspend_readonly(world, &readonly_state);
     ecs_set(world, id, EcsEnum, { .underlying_type = underlying_type });
     flecs_resume_readonly(world, &readonly_state);
+#else
+    /* Make sure that enums still behave the same even without meta */
+    ecs_add_id(world, id, EcsExclusive);
+    ecs_add_id(world, id, EcsOneOf);
 #endif
 }
 
diff --git a/test/custom_builds/cpp/enum_reflection_no_meta/src/main.cpp b/test/custom_builds/cpp/enum_reflection_no_meta/src/main.cpp
@@ -80,5 +80,24 @@ int main(int argc, char *argv[]) {
         }
     }
 
+    flecs::entity e = world.entity();
+
+    e.add(Color::Red);
+    if (!e.has(Color::Red)) {
+        std::cout << "Entity doesn't have Color::Red\n";
+        return -1;
+    }
+
+    e.add(Color::Green);
+    if (!e.has(Color::Green)) {
+        std::cout << "Entity doesn't have Color::Green\n";
+        return -1;
+    }
+
+    if (e.has(Color::Red)) {
+        std::cout << "Entity has Color::Red\n";
+        return -1;
+    }
+
     return 0;
 }
diff --git a/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/.gitignore b/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/.gitignore
@@ -0,0 +1,5 @@
+.bake_cache
+.DS_Store
+.vscode
+gcov
+bin
diff --git a/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/include/enum_reflection_no_meta/bake_config.h b/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/include/enum_reflection_no_meta/bake_config.h
@@ -0,0 +1,24 @@
+/*
+                                   )
+                                  (.)
+                                  .|.
+                                  | |
+                              _.--| |--._
+                           .-';  ;`-'& ; `&.
+                          \   &  ;    &   &_/
+                           |"""---...---"""|
+                           \ | | | | | | | /
+                            `---.|.|.|.---'
+
+ * This file is generated by bake.lang.c for your convenience. Headers of
+ * dependencies will automatically show up in this file. Include bake_config.h
+ * in your main project file. Do not edit! */
+
+#ifndef ENUM_REFLECTION_NO_META_BAKE_CONFIG_H
+#define ENUM_REFLECTION_NO_META_BAKE_CONFIG_H
+
+/* Headers of public dependencies */
+#include "../../deps/flecs.h"
+
+#endif
+
diff --git a/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/include/enum_reflection_no_meta_no_auto_registration.h b/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/include/enum_reflection_no_meta_no_auto_registration.h
@@ -0,0 +1,16 @@
+#ifndef ENUM_REFLECTION_NO_META_NO_AUTO_REGISTRATION_H
+#define ENUM_REFLECTION_NO_META_NO_AUTO_REGISTRATION_H
+
+/* This generated file contains includes for project dependencies */
+#include "enum_reflection_no_meta_no_auto_registration/bake_config.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
diff --git a/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/include/enum_reflection_no_meta_no_auto_registration/bake_config.h b/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/include/enum_reflection_no_meta_no_auto_registration/bake_config.h
@@ -0,0 +1,24 @@
+/*
+                                   )
+                                  (.)
+                                  .|.
+                                  | |
+                              _.--| |--._
+                           .-';  ;`-'& ; `&.
+                          \   &  ;    &   &_/
+                           |"""---...---"""|
+                           \ | | | | | | | /
+                            `---.|.|.|.---'
+
+ * This file is generated by bake.lang.c for your convenience. Headers of
+ * dependencies will automatically show up in this file. Include bake_config.h
+ * in your main project file. Do not edit! */
+
+#ifndef ENUM_REFLECTION_NO_META_NO_AUTO_REGISTRATION_BAKE_CONFIG_H
+#define ENUM_REFLECTION_NO_META_NO_AUTO_REGISTRATION_BAKE_CONFIG_H
+
+/* Headers of public dependencies */
+#include "../../deps/flecs.h"
+
+#endif
+
diff --git a/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/project.json b/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/project.json
@@ -0,0 +1,15 @@
+{
+    "id": "enum_reflection_no_meta_no_auto_registration",
+    "type": "application",
+    "value": {
+        "use": [
+            "flecs"
+        ],
+        "language": "c++",
+        "public": false,
+        "standalone": true
+    },
+    "lang.cpp": {
+        "defines": ["FLECS_CUSTOM_BUILD", "FLECS_CPP", "FLECS_CPP_NO_AUTO_REGISTRATION"]
+    }
+}
diff --git a/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/src/main.cpp b/test/custom_builds/cpp/enum_reflection_no_meta_no_auto_registration/src/main.cpp
@@ -0,0 +1,103 @@
+#include <enum_reflection_no_meta_no_auto_registration.h>
+#include <iostream>
+
+// Test if enum reflection works without the meta addon
+
+enum Color {
+    Red, Green, Blue
+};
+
+int main(int argc, char *argv[]) {
+    flecs::world world(argc, argv);
+
+    flecs::entity c = world.component<Color>();
+
+    if (!world.is_alive(flecs::Constant)) {
+        std::cout << "Constant tag is not alive\n";
+        return -1;
+    }
+
+    {
+        flecs::entity constant = c.lookup("Red");
+        if (!constant) {
+            std::cout << "Constant not found\n";
+            return -1;
+        }
+
+        using U = std::underlying_type<Color>::type;
+
+        if (!constant.has(flecs::Constant, world.id<U>())) {
+            std::cout << "Constant pair not found on constant\n";
+            return -1;
+        }
+
+        const U *v = constant.get_second<U>(flecs::Constant);
+        if (*v != Red) {
+            std::cout << "Constant has wrong value\n";
+            return -1;
+        }
+    }
+
+    {
+        flecs::entity constant = c.lookup("Green");
+        if (!constant) {
+            std::cout << "Constant not found\n";
+            return -1;
+        }
+
+        using U = std::underlying_type<Color>::type;
+
+        if (!constant.has(flecs::Constant, world.id<U>())) {
+            std::cout << "Constant pair not found on constant\n";
+            return -1;
+        }
+
+        const U *v = constant.get_second<U>(flecs::Constant);
+        if (*v != Green) {
+            std::cout << "Constant has wrong value\n";
+            return -1;
+        }
+    }
+
+    {
+        flecs::entity constant = c.lookup("Blue");
+        if (!constant) {
+            std::cout << "Constant not found\n";
+            return -1;
+        }
+
+        using U = std::underlying_type<Color>::type;
+
+        if (!constant.has(flecs::Constant, world.id<U>())) {
+            std::cout << "Constant pair not found on constant\n";
+            return -1;
+        }
+
+        const U *v = constant.get_second<U>(flecs::Constant);
+        if (*v != Blue) {
+            std::cout << "Constant has wrong value\n";
+            return -1;
+        }
+    }
+
+    flecs::entity e = world.entity();
+
+    e.add(Color::Red);
+    if (!e.has(Color::Red)) {
+        std::cout << "Entity doesn't have Color::Red\n";
+        return -1;
+    }
+
+    e.add(Color::Green);
+    if (!e.has(Color::Green)) {
+        std::cout << "Entity doesn't have Color::Green\n";
+        return -1;
+    }
+
+    if (e.has(Color::Red)) {
+        std::cout << "Entity has Color::Red\n";
+        return -1;
+    }
+
+    return 0;
+}

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +.bake_cache
 +.DS_Store
 +.vscode
 +gcov
 +bin