Compute flecs C++ type/symbol name at most once

Summary: This diff upstreams a fix that ensures that the C++ type/symbol names are computed at most once, and fixes an issue where the name buffers could be written to simultaneously by different threads.

Differential Revision: D62050989

Author: SanderMertens

distr/flecs.h

@@ -26534,7 +26534,8 @@ inline const char* type_name() {
     static const size_t len = ECS_FUNC_TYPE_LEN(const char*, type_name, ECS_FUNC_NAME);
     static char result[len + 1] = {};
     static const size_t front_len = ECS_FUNC_NAME_FRONT(const char*, type_name);
-    return ecs_cpp_get_type_name(result, ECS_FUNC_NAME, len, front_len);
+    static const char* cppTypeName = ecs_cpp_get_type_name(result, ECS_FUNC_NAME, len, front_len);
+    return cppTypeName;
 }
 #else
 #error "implicit component registration not supported"
@@ -26546,7 +26547,8 @@ template <typename T>
 inline const char* symbol_name() {
     static const size_t len = ECS_FUNC_TYPE_LEN(const char*, symbol_name, ECS_FUNC_NAME);
     static char result[len + 1] = {};
-    return ecs_cpp_get_symbol_name(result, type_name<T>(), len);
+    static const char* cppSymbolName = ecs_cpp_get_symbol_name(result, type_name<T>(), len);
+    return cppSymbolName;
 }
 
 template <> inline const char* symbol_name<uint8_t>() {

include/flecs/addons/cpp/component.hpp

@@ -34,7 +34,8 @@ inline const char* type_name() {
     static const size_t len = ECS_FUNC_TYPE_LEN(const char*, type_name, ECS_FUNC_NAME);
     static char result[len + 1] = {};
     static const size_t front_len = ECS_FUNC_NAME_FRONT(const char*, type_name);
-    return ecs_cpp_get_type_name(result, ECS_FUNC_NAME, len, front_len);
+    static const char* cppTypeName = ecs_cpp_get_type_name(result, ECS_FUNC_NAME, len, front_len);
+    return cppTypeName;
 }
 #else
 #error "implicit component registration not supported"
@@ -46,7 +47,8 @@ template <typename T>
 inline const char* symbol_name() {
     static const size_t len = ECS_FUNC_TYPE_LEN(const char*, symbol_name, ECS_FUNC_NAME);
     static char result[len + 1] = {};
-    return ecs_cpp_get_symbol_name(result, type_name<T>(), len);
+    static const char* cppSymbolName = ecs_cpp_get_symbol_name(result, type_name<T>(), len);
+    return cppSymbolName;
 }
 
 template <> inline const char* symbol_name<uint8_t>() {