Enforce minimum supported libsqlite version

The server now checks the libsqlite both at compile time and on server
startup. The version the executable was built with and the one it's
running with may be different, so long as they're both at or above the
minimum supported version. One or both version numbers are printed on
startup, depending on if they're identical or not.

The compile-time ("Built with") version depends on the sqlite3.h header
used during compilation, while the runtime ("Using") version depends on
either:

* The sqlite3.c version used during compilation, if statically linked.
  (Which may be different from the header version and still compile and run
  fine.)
* The version of the libsqlite3.so or sqlite3.dll that the server
  loaded, if dynamically linked. Version mismatches here are normal,
  especially on Unix systems with their own system libraries.

The current minimum version is 3.33.0, from 2020-08-14, as that's the
one that introduced the UPDATE-FROM syntax used during login by
Database::updateSelectedByPlayerId().

Also rearranged the prints and initialization calls in main() slightly.

README.md

@@ -83,7 +83,7 @@ This just works if you're all under the same LAN, but if you want to play over t
 
 ## Compiling 
 
-OpenFusion has one external dependency: SQLite. You can install it on Windows using `vcpkg`, and on Unix/Linux using your distribution's package manager. For a more indepth guide on how to set up vcpkg, [read this guide on the wiki](https://github.com/OpenFusionProject/OpenFusion/wiki/Installing-SQLite-on-Windows-using-vcpkg).
+OpenFusion has one external dependency: SQLite. The oldest compatible version is `3.33.0`. You can install it on Windows using `vcpkg`, and on Unix/Linux using your distribution's package manager. For a more indepth guide on how to set up vcpkg, [read this guide on the wiki](https://github.com/OpenFusionProject/OpenFusion/wiki/Installing-SQLite-on-Windows-using-vcpkg).
 
 You have two choices for compiling OpenFusion: the included Makefile and the included CMakeLists file.
 

src/db/Database.hpp

@@ -41,6 +41,7 @@ namespace Database {
         uint64_t Timestamp;
     };
     
+    void init();
     void open();
     void close();
 

src/db/init.cpp

@@ -236,7 +236,20 @@ static int getTableSize(std::string tableName) {
     return result;
 }
 
+void Database::init() {
+    std::cout << "[INFO] Built with libsqlite " SQLITE_VERSION << std::endl;
+
+    if (sqlite3_libversion_number() != SQLITE_VERSION_NUMBER)
+        std::cout << "[INFO] Using libsqlite " << std::string(sqlite3_libversion()) << std::endl;
+
+    if (sqlite3_libversion_number() < MIN_SUPPORTED_SQLITE_NUMBER) {
+        std::cerr << "[FATAL] Runtime sqlite version too old. Minimum compatible version: " MIN_SUPPORTED_SQLITE << std::endl;
+        exit(1);
+    }
+}
+
 void Database::open() {
+
     // XXX: move locks here
     int rc = sqlite3_open(settings::DBPATH.c_str(), &db);
     if (rc != SQLITE_OK) {

src/db/internal.hpp

@@ -3,6 +3,15 @@
 #include "db/Database.hpp"
 #include <sqlite3.h>
 
+#define MIN_SUPPORTED_SQLITE_NUMBER 3033000
+#define MIN_SUPPORTED_SQLITE "3.33.0"
+// we can't use this in #error, since it doesn't expand macros
+
+// Compile-time libsqlite version check
+#if SQLITE_VERSION_NUMBER < MIN_SUPPORTED_SQLITE_NUMBER
+#error libsqlite version too old. Minimum compatible version: 3.33.0
+#endif
+
 extern std::mutex dbCrit;
 extern sqlite3 *db;
 

src/main.cpp

@@ -98,6 +98,9 @@ void initsignals() {
 }
 
 int main() {
+    std::cout << "[INFO] OpenFusion v" GIT_VERSION << std::endl;
+    std::cout << "[INFO] Protocol version: " << PROTOCOL_VERSION << std::endl;
+
 #ifdef _WIN32
     WSADATA wsaData;
     if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0) {
@@ -105,15 +108,15 @@ int main() {
         exit(EXIT_FAILURE);
     }
 #endif
+
     initsignals();
     settings::init();
-
-    std::cout << "[INFO] OpenFusion v" GIT_VERSION << std::endl;
-    std::cout << "[INFO] Protocol version: " << PROTOCOL_VERSION << std::endl;
-    std::cout << "[INFO] Intializing Packet Managers..." << std::endl;
-
+    Database::init();
     Rand::init(getTime());
     TableData::init();
+
+    std::cout << "[INFO] Intializing Packet Managers..." << std::endl;
+
     PlayerManager::init();
     PlayerMovement::init();
     BuiltinCommands::init();
@@ -132,9 +135,10 @@ int main() {
     Email::init();
     Groups::init();
     Racing::init();
-    Database::open();
     Trading::init();
 
+    Database::open();
+
     switch (settings::EVENTMODE) {
     case 0: break; // no event
     case 1: std::cout << "[INFO] Event active. Hey, Hey It's Knishmas!" << std::endl; break;