Update: Translations from eints

[openttd-github.git] / src / script / squirrel.cpp

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file squirrel.cpp the implementation of the Squirrel class. It handles all Squirrel-stuff and gives a nice API back to work with. */

#include "../stdafx.h"
#include "../debug.h"
#include "squirrel_std.hpp"
#include "../fileio_func.h"
#include "../string_func.h"
#include "script_fatalerror.hpp"
#include "../settings_type.h"
#include <sqstdaux.h>
#include <../squirrel/sqpcheader.h>
#include <../squirrel/sqvm.h>
#include "../core/alloc_func.hpp"

/**
 * In the memory allocator for Squirrel we want to directly use malloc/realloc, so when the OS
 * does not have enough memory the game does not go into unrecoverable error mode and kill the
 * whole game, but rather let the AI die though then we need to circumvent MallocT/ReallocT.
 *
 * So no #include "../safeguards.h" here as is required, but after the allocator's implementation.
 */

/*
 * If changing the call paths into the scripting engine, define this symbol to enable full debugging of allocations.
 * This lets you track whether the allocator context is being switched correctly in all call paths.
#define SCRIPT_DEBUG_ALLOCATIONS
 */

struct ScriptAllocator {
        size_t allocated_size;   ///< Sum of allocated data size
        size_t allocation_limit; ///< Maximum this allocator may use before allocations fail
        /**
         * Whether the error has already been thrown, so to not throw secondary errors in
         * the handling of the allocation error. This as the handling of the error will
         * throw a Squirrel error so the Squirrel stack can be dumped, however that gets
         * allocated by this allocator and then you might end up in an infinite loop.
         */
        bool error_thrown;

        static const size_t SAFE_LIMIT = 0x8000000; ///< 128 MiB, a safe choice for almost any situation

#ifdef SCRIPT_DEBUG_ALLOCATIONS
        std::map<void *, size_t> allocations;
#endif

        void CheckLimit() const
        {
                if (this->allocated_size > this->allocation_limit) throw Script_FatalError("Maximum memory allocation exceeded");
        }

        /**
         * Catch all validation for the allocation; did it allocate too much memory according
         * to the allocation limit or did the allocation at the OS level maybe fail? In those
         * error situations a Script_FatalError is thrown, but once that has been done further
         * allocations are allowed to make it possible for Squirrel to throw the error and
         * clean everything up.
         * @param requested_size The requested size that was requested to be allocated.
         * @param p              The pointer to the allocated object, or null if allocation failed.
         */
        void CheckAllocation(size_t requested_size, void *p)
        {
                if (this->allocated_size + requested_size > this->allocation_limit && !this->error_thrown) {
                        /* Do not allow allocating more than the allocation limit, except when an error is
                         * already as then the allocation is for throwing that error in Squirrel, the
                         * associated stack trace information and while cleaning up the AI. */
                        this->error_thrown = true;
                        std::string msg = fmt::format("Maximum memory allocation exceeded by {} bytes when allocating {} bytes",
                                this->allocated_size + requested_size - this->allocation_limit, requested_size);
                        /* Don't leak the rejected allocation. */
                        free(p);
                        throw Script_FatalError(msg);
                }

                if (p == nullptr) {
                        /* The OS did not have enough memory to allocate the object, regardless of the
                         * limit imposed by OpenTTD on the amount of memory that may be allocated. */
                        if (this->error_thrown) {
                                /* The allocation is called in the error handling of a memory allocation
                                 * failure, then not being able to allocate that small amount of memory
                                 * means there is no other choice than to bug out completely. */
                                MallocError(requested_size);
                        }

                        this->error_thrown = true;
                        std::string msg = fmt::format("Out of memory. Cannot allocate {} bytes", requested_size);
                        throw Script_FatalError(msg);
                }
        }

        void *Malloc(SQUnsignedInteger size)
        {
                void *p = malloc(size);

                this->CheckAllocation(size, p);

                this->allocated_size += size;

#ifdef SCRIPT_DEBUG_ALLOCATIONS
                assert(p != nullptr);
                assert(this->allocations.find(p) == this->allocations.end());
                this->allocations[p] = size;
#endif

                return p;
        }

        void *Realloc(void *p, SQUnsignedInteger oldsize, SQUnsignedInteger size)
        {
                if (p == nullptr) {
                        return this->Malloc(size);
                }
                if (size == 0) {
                        this->Free(p, oldsize);
                        return nullptr;
                }

#ifdef SCRIPT_DEBUG_ALLOCATIONS
                assert(this->allocations[p] == oldsize);
                this->allocations.erase(p);
#endif
                /* Can't use realloc directly because memory limit check.
                 * If memory exception is thrown, the old pointer is expected
                 * to be valid for engine cleanup.
                 */
                void *new_p = malloc(size);

                this->CheckAllocation(size - oldsize, new_p);

                /* Memory limit test passed, we can copy data and free old pointer. */
                memcpy(new_p, p, std::min(oldsize, size));
                free(p);

                this->allocated_size -= oldsize;
                this->allocated_size += size;

#ifdef SCRIPT_DEBUG_ALLOCATIONS
                assert(new_p != nullptr);
                assert(this->allocations.find(p) == this->allocations.end());
                this->allocations[new_p] = size;
#endif

                return new_p;
        }

        void Free(void *p, SQUnsignedInteger size)
        {
                if (p == nullptr) return;
                free(p);
                this->allocated_size -= size;

#ifdef SCRIPT_DEBUG_ALLOCATIONS
                assert(this->allocations.at(p) == size);
                this->allocations.erase(p);
#endif
        }

        ScriptAllocator()
        {
                this->allocated_size = 0;
                this->allocation_limit = static_cast<size_t>(_settings_game.script.script_max_memory_megabytes) << 20;
                if (this->allocation_limit == 0) this->allocation_limit = SAFE_LIMIT; // in case the setting is somehow zero
                this->error_thrown = false;
        }

        ~ScriptAllocator()
        {
#ifdef SCRIPT_DEBUG_ALLOCATIONS
                assert(this->allocations.empty());
#endif
        }
};

/**
 * In the memory allocator for Squirrel we want to directly use malloc/realloc, so when the OS
 * does not have enough memory the game does not go into unrecoverable error mode and kill the
 * whole game, but rather let the AI die though then we need to circumvent MallocT/ReallocT.
 * For the rest of this code, the safeguards should be in place though!
 */
#include "../safeguards.h"

ScriptAllocator *_squirrel_allocator = nullptr;

/* See 3rdparty/squirrel/squirrel/sqmem.cpp for the default allocator implementation, which this overrides */
#ifndef SQUIRREL_DEFAULT_ALLOCATOR
void *sq_vm_malloc(SQUnsignedInteger size) { return _squirrel_allocator->Malloc(size); }
void *sq_vm_realloc(void *p, SQUnsignedInteger oldsize, SQUnsignedInteger size) { return _squirrel_allocator->Realloc(p, oldsize, size); }
void sq_vm_free(void *p, SQUnsignedInteger size) { _squirrel_allocator->Free(p, size); }
#endif

size_t Squirrel::GetAllocatedMemory() const noexcept
{
        assert(this->allocator != nullptr);
        return this->allocator->allocated_size;
}


void Squirrel::CompileError(HSQUIRRELVM vm, const SQChar *desc, const SQChar *source, SQInteger line, SQInteger column)
{
        std::string msg = fmt::format("Error {}:{}/{}: {}", source, line, column, desc);

        /* Check if we have a custom print function */
        Squirrel *engine = (Squirrel *)sq_getforeignptr(vm);
        engine->crashed = true;
        SQPrintFunc *func = engine->print_func;
        if (func == nullptr) {
                Debug(misc, 0, "[Squirrel] Compile error: {}", msg);
        } else {
                (*func)(true, msg);
        }
}

void Squirrel::ErrorPrintFunc(HSQUIRRELVM vm, const std::string &s)
{
        /* Check if we have a custom print function */
        SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;
        if (func == nullptr) {
                fmt::print(stderr, "{}", s);
        } else {
                (*func)(true, s);
        }
}

void Squirrel::RunError(HSQUIRRELVM vm, const SQChar *error)
{
        /* Set the print function to something that prints to stderr */
        SQPRINTFUNCTION pf = sq_getprintfunc(vm);
        sq_setprintfunc(vm, &Squirrel::ErrorPrintFunc);

        /* Check if we have a custom print function */
        std::string msg = fmt::format("Your script made an error: {}\n", error);
        Squirrel *engine = (Squirrel *)sq_getforeignptr(vm);
        SQPrintFunc *func = engine->print_func;
        if (func == nullptr) {
                fmt::print(stderr, "{}", msg);
        } else {
                (*func)(true, msg);
        }

        /* Print below the error the stack, so the users knows what is happening */
        sqstd_printcallstack(vm);
        /* Reset the old print function */
        sq_setprintfunc(vm, pf);
}

SQInteger Squirrel::_RunError(HSQUIRRELVM vm)
{
        const SQChar *sErr = nullptr;

        if (sq_gettop(vm) >= 1) {
                if (SQ_SUCCEEDED(sq_getstring(vm, -1, &sErr))) {
                        Squirrel::RunError(vm, sErr);
                        return 0;
                }
        }

        Squirrel::RunError(vm, "unknown error");
        return 0;
}

void Squirrel::PrintFunc(HSQUIRRELVM vm, const std::string &s)
{
        /* Check if we have a custom print function */
        SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;
        if (func == nullptr) {
                fmt::print("{}", s);
        } else {
                (*func)(false, s);
        }
}

void Squirrel::AddMethod(const char *method_name, SQFUNCTION proc, uint nparam, const char *params, void *userdata, int size)
{
        ScriptAllocatorScope alloc_scope(this);

        sq_pushstring(this->vm, method_name, -1);

        if (size != 0) {
                void *ptr = sq_newuserdata(vm, size);
                memcpy(ptr, userdata, size);
        }

        sq_newclosure(this->vm, proc, size != 0 ? 1 : 0);
        if (nparam != 0) sq_setparamscheck(this->vm, nparam, params);
        sq_setnativeclosurename(this->vm, -1, method_name);
        sq_newslot(this->vm, -3, SQFalse);
}

void Squirrel::AddConst(const char *var_name, int value)
{
        ScriptAllocatorScope alloc_scope(this);

        sq_pushstring(this->vm, var_name, -1);
        sq_pushinteger(this->vm, value);
        sq_newslot(this->vm, -3, SQTrue);
}

void Squirrel::AddConst(const char *var_name, bool value)
{
        ScriptAllocatorScope alloc_scope(this);

        sq_pushstring(this->vm, var_name, -1);
        sq_pushbool(this->vm, value);
        sq_newslot(this->vm, -3, SQTrue);
}

void Squirrel::AddClassBegin(const char *class_name)
{
        ScriptAllocatorScope alloc_scope(this);

        sq_pushroottable(this->vm);
        sq_pushstring(this->vm, class_name, -1);
        sq_newclass(this->vm, SQFalse);
}

void Squirrel::AddClassBegin(const char *class_name, const char *parent_class)
{
        ScriptAllocatorScope alloc_scope(this);

        sq_pushroottable(this->vm);
        sq_pushstring(this->vm, class_name, -1);
        sq_pushstring(this->vm, parent_class, -1);
        if (SQ_FAILED(sq_get(this->vm, -3))) {
                Debug(misc, 0, "[squirrel] Failed to initialize class '{}' based on parent class '{}'", class_name, parent_class);
                Debug(misc, 0, "[squirrel] Make sure that '{}' exists before trying to define '{}'", parent_class, class_name);
                return;
        }
        sq_newclass(this->vm, SQTrue);
}

void Squirrel::AddClassEnd()
{
        ScriptAllocatorScope alloc_scope(this);

        sq_newslot(vm, -3, SQFalse);
        sq_pop(vm, 1);
}

bool Squirrel::MethodExists(HSQOBJECT instance, const char *method_name)
{
        assert(!this->crashed);
        ScriptAllocatorScope alloc_scope(this);

        int top = sq_gettop(this->vm);
        /* Go to the instance-root */
        sq_pushobject(this->vm, instance);
        /* Find the function-name inside the script */
        sq_pushstring(this->vm, method_name, -1);
        if (SQ_FAILED(sq_get(this->vm, -2))) {
                sq_settop(this->vm, top);
                return false;
        }
        sq_settop(this->vm, top);
        return true;
}

bool Squirrel::Resume(int suspend)
{
        assert(!this->crashed);
        ScriptAllocatorScope alloc_scope(this);

        /* Did we use more operations than we should have in the
         * previous tick? If so, subtract that from the current run. */
        if (this->overdrawn_ops > 0 && suspend > 0) {
                this->overdrawn_ops -= suspend;
                /* Do we need to wait even more? */
                if (this->overdrawn_ops >= 0) return true;

                /* We can now only run whatever is "left". */
                suspend = -this->overdrawn_ops;
        }

        this->crashed = !sq_resumecatch(this->vm, suspend);
        this->overdrawn_ops = -this->vm->_ops_till_suspend;
        this->allocator->CheckLimit();
        return this->vm->_suspended != 0;
}

void Squirrel::ResumeError()
{
        assert(!this->crashed);
        ScriptAllocatorScope alloc_scope(this);
        sq_resumeerror(this->vm);
}

void Squirrel::CollectGarbage()
{
        ScriptAllocatorScope alloc_scope(this);
        sq_collectgarbage(this->vm);
}

bool Squirrel::CallMethod(HSQOBJECT instance, const char *method_name, HSQOBJECT *ret, int suspend)
{
        assert(!this->crashed);
        ScriptAllocatorScope alloc_scope(this);
        this->allocator->CheckLimit();

        /* Store the stack-location for the return value. We need to
         * restore this after saving or the stack will be corrupted
         * if we're in the middle of a DoCommand. */
        SQInteger last_target = this->vm->_suspended_target;
        /* Store the current top */
        int top = sq_gettop(this->vm);
        /* Go to the instance-root */
        sq_pushobject(this->vm, instance);
        /* Find the function-name inside the script */
        sq_pushstring(this->vm, method_name, -1);
        if (SQ_FAILED(sq_get(this->vm, -2))) {
                Debug(misc, 0, "[squirrel] Could not find '{}' in the class", method_name);
                sq_settop(this->vm, top);
                return false;
        }
        /* Call the method */
        sq_pushobject(this->vm, instance);
        if (SQ_FAILED(sq_call(this->vm, 1, ret == nullptr ? SQFalse : SQTrue, SQTrue, suspend))) return false;
        if (ret != nullptr) sq_getstackobj(vm, -1, ret);
        /* Reset the top, but don't do so for the script main function, as we need
         *  a correct stack when resuming. */
        if (suspend == -1 || !this->IsSuspended()) sq_settop(this->vm, top);
        /* Restore the return-value location. */
        this->vm->_suspended_target = last_target;

        return true;
}

bool Squirrel::CallStringMethod(HSQOBJECT instance, const char *method_name, std::string *res, int suspend)
{
        HSQOBJECT ret;
        if (!this->CallMethod(instance, method_name, &ret, suspend)) return false;
        if (ret._type != OT_STRING) return false;
        *res = StrMakeValid(ObjectToString(&ret));
        return true;
}

bool Squirrel::CallIntegerMethod(HSQOBJECT instance, const char *method_name, int *res, int suspend)
{
        HSQOBJECT ret;
        if (!this->CallMethod(instance, method_name, &ret, suspend)) return false;
        if (ret._type != OT_INTEGER) return false;
        *res = ObjectToInteger(&ret);
        return true;
}

bool Squirrel::CallBoolMethod(HSQOBJECT instance, const char *method_name, bool *res, int suspend)
{
        HSQOBJECT ret;
        if (!this->CallMethod(instance, method_name, &ret, suspend)) return false;
        if (ret._type != OT_BOOL) return false;
        *res = ObjectToBool(&ret);
        return true;
}

/* static */ bool Squirrel::CreateClassInstanceVM(HSQUIRRELVM vm, const std::string &class_name, void *real_instance, HSQOBJECT *instance, SQRELEASEHOOK release_hook, bool prepend_API_name)
{
        Squirrel *engine = (Squirrel *)sq_getforeignptr(vm);

        int oldtop = sq_gettop(vm);

        /* First, find the class */
        sq_pushroottable(vm);

        if (prepend_API_name) {
                std::string prepended_class_name = engine->GetAPIName();
                prepended_class_name += class_name;
                sq_pushstring(vm, prepended_class_name, -1);
        } else {
                sq_pushstring(vm, class_name, -1);
        }

        if (SQ_FAILED(sq_get(vm, -2))) {
                Debug(misc, 0, "[squirrel] Failed to find class by the name '{}{}'", prepend_API_name ? engine->GetAPIName() : "", class_name);
                sq_settop(vm, oldtop);
                return false;
        }

        /* Create the instance */
        if (SQ_FAILED(sq_createinstance(vm, -1))) {
                Debug(misc, 0, "[squirrel] Failed to create instance for class '{}{}'", prepend_API_name ? engine->GetAPIName() : "", class_name);
                sq_settop(vm, oldtop);
                return false;
        }

        if (instance != nullptr) {
                /* Find our instance */
                sq_getstackobj(vm, -1, instance);
                /* Add a reference to it, so it survives for ever */
                sq_addref(vm, instance);
        }
        sq_remove(vm, -2); // Class-name
        sq_remove(vm, -2); // Root-table

        /* Store it in the class */
        sq_setinstanceup(vm, -1, real_instance);
        if (release_hook != nullptr) sq_setreleasehook(vm, -1, release_hook);

        if (instance != nullptr) sq_settop(vm, oldtop);

        return true;
}

bool Squirrel::CreateClassInstance(const std::string &class_name, void *real_instance, HSQOBJECT *instance)
{
        ScriptAllocatorScope alloc_scope(this);
        return Squirrel::CreateClassInstanceVM(this->vm, class_name, real_instance, instance, nullptr);
}

Squirrel::Squirrel(const char *APIName) :
        APIName(APIName), allocator(new ScriptAllocator())
{
        this->Initialize();
}

void Squirrel::Initialize()
{
        ScriptAllocatorScope alloc_scope(this);

        this->global_pointer = nullptr;
        this->print_func = nullptr;
        this->crashed = false;
        this->overdrawn_ops = 0;
        this->vm = sq_open(1024);

        /* Handle compile-errors ourself, so we can display it nicely */
        sq_setcompilererrorhandler(this->vm, &Squirrel::CompileError);
        sq_notifyallexceptions(this->vm, _debug_script_level > 5);
        /* Set a good print-function */
        sq_setprintfunc(this->vm, &Squirrel::PrintFunc);
        /* Handle runtime-errors ourself, so we can display it nicely */
        sq_newclosure(this->vm, &Squirrel::_RunError, 0);
        sq_seterrorhandler(this->vm);

        /* Set the foreign pointer, so we can always find this instance from within the VM */
        sq_setforeignptr(this->vm, this);

        sq_pushroottable(this->vm);
        squirrel_register_global_std(this);

        /* Set consts table as delegate of root table, so consts/enums defined via require() are accessible */
        sq_pushconsttable(this->vm);
        sq_setdelegate(this->vm, -2);
}

class SQFile {
private:
        FileHandle file;
        size_t size;
        size_t pos;

public:
        SQFile(FileHandle file, size_t size) : file(std::move(file)), size(size), pos(0) {}

        size_t Read(void *buf, size_t elemsize, size_t count)
        {
                assert(elemsize != 0);
                if (this->pos + (elemsize * count) > this->size) {
                        count = (this->size - this->pos) / elemsize;
                }
                if (count == 0) return 0;
                size_t ret = fread(buf, elemsize, count, this->file);
                this->pos += ret * elemsize;
                return ret;
        }
};

static char32_t _io_file_lexfeed_ASCII(SQUserPointer file)
{
        unsigned char c;
        if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) return c;
        return 0;
}

static char32_t _io_file_lexfeed_UTF8(SQUserPointer file)
{
        char buffer[5];

        /* Read the first character, and get the length based on UTF-8 specs. If invalid, bail out. */
        if (((SQFile *)file)->Read(buffer, sizeof(buffer[0]), 1) != 1) return 0;
        uint len = Utf8EncodedCharLen(buffer[0]);
        if (len == 0) return -1;

        /* Read the remaining bits. */
        if (len > 1 && ((SQFile *)file)->Read(buffer + 1, sizeof(buffer[0]), len - 1) != len - 1) return 0;

        /* Convert the character, and when definitely invalid, bail out as well. */
        char32_t c;
        if (Utf8Decode(&c, buffer) != len) return -1;

        return c;
}

static char32_t _io_file_lexfeed_UCS2_no_swap(SQUserPointer file)
{
        unsigned short c;
        if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) return (char32_t)c;
        return 0;
}

static char32_t _io_file_lexfeed_UCS2_swap(SQUserPointer file)
{
        unsigned short c;
        if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) {
                c = ((c >> 8) & 0x00FF)| ((c << 8) & 0xFF00);
                return (char32_t)c;
        }
        return 0;
}

static SQInteger _io_file_read(SQUserPointer file, SQUserPointer buf, SQInteger size)
{
        SQInteger ret = ((SQFile *)file)->Read(buf, 1, size);
        if (ret == 0) return -1;
        return ret;
}

SQRESULT Squirrel::LoadFile(HSQUIRRELVM vm, const std::string &filename, SQBool printerror)
{
        ScriptAllocatorScope alloc_scope(this);

        std::optional<FileHandle> file = std::nullopt;
        size_t size;
        if (strncmp(this->GetAPIName(), "AI", 2) == 0) {
                file = FioFOpenFile(filename, "rb", AI_DIR, &size);
                if (!file.has_value()) file = FioFOpenFile(filename, "rb", AI_LIBRARY_DIR, &size);
        } else if (strncmp(this->GetAPIName(), "GS", 2) == 0) {
                file = FioFOpenFile(filename, "rb", GAME_DIR, &size);
                if (!file.has_value()) file = FioFOpenFile(filename, "rb", GAME_LIBRARY_DIR, &size);
        } else {
                NOT_REACHED();
        }

        if (!file.has_value()) {
                return sq_throwerror(vm, "cannot open the file");
        }
        unsigned short bom = 0;
        if (size >= 2) {
                if (fread(&bom, 1, sizeof(bom), *file) != sizeof(bom)) return sq_throwerror(vm, "cannot read the file");;
        }

        SQLEXREADFUNC func;
        switch (bom) {
                case SQ_BYTECODE_STREAM_TAG: { // BYTECODE
                        if (fseek(*file, -2, SEEK_CUR) < 0) {
                                return sq_throwerror(vm, "cannot seek the file");
                        }

                        SQFile f(std::move(*file), size);
                        if (SQ_SUCCEEDED(sq_readclosure(vm, _io_file_read, &f))) {
                                return SQ_OK;
                        }
                        return sq_throwerror(vm, "Couldn't read bytecode");
                }
                case 0xFFFE:
                        /* Either this file is encoded as big-endian and we're on a little-endian
                         * machine, or this file is encoded as little-endian and we're on a big-endian
                         * machine. Either way, swap the bytes of every word we read. */
                        func = _io_file_lexfeed_UCS2_swap;
                        size -= 2; // Skip BOM
                        break;
                case 0xFEFF:
                        func = _io_file_lexfeed_UCS2_no_swap;
                        size -= 2; // Skip BOM
                        break;
                case 0xBBEF:   // UTF-8
                case 0xEFBB: { // UTF-8 on big-endian machine
                        /* Similarly, check the file is actually big enough to finish checking BOM */
                        if (size < 3) {
                                return sq_throwerror(vm, "I/O error");
                        }
                        unsigned char uc;
                        if (fread(&uc, 1, sizeof(uc), *file) != sizeof(uc) || uc != 0xBF) {
                                return sq_throwerror(vm, "Unrecognized encoding");
                        }
                        func = _io_file_lexfeed_UTF8;
                        size -= 3; // Skip BOM
                        break;
                }
                default: // ASCII
                        func = _io_file_lexfeed_ASCII;
                        /* Account for when we might not have fread'd earlier */
                        if (size >= 2 && fseek(*file, -2, SEEK_CUR) < 0) {
                                return sq_throwerror(vm, "cannot seek the file");
                        }
                        break;
        }

        SQFile f(std::move(*file), size);
        if (SQ_SUCCEEDED(sq_compile(vm, func, &f, filename.c_str(), printerror))) {
                return SQ_OK;
        }
        return SQ_ERROR;
}

bool Squirrel::LoadScript(HSQUIRRELVM vm, const std::string &script, bool in_root)
{
        ScriptAllocatorScope alloc_scope(this);

        /* Make sure we are always in the root-table */
        if (in_root) sq_pushroottable(vm);

        SQInteger ops_left = vm->_ops_till_suspend;
        /* Load and run the script */
        if (SQ_SUCCEEDED(LoadFile(vm, script, SQTrue))) {
                sq_push(vm, -2);
                if (SQ_SUCCEEDED(sq_call(vm, 1, SQFalse, SQTrue, 100000))) {
                        sq_pop(vm, 1);
                        /* After compiling the file we want to reset the amount of opcodes. */
                        vm->_ops_till_suspend = ops_left;
                        return true;
                }
        }

        vm->_ops_till_suspend = ops_left;
        Debug(misc, 0, "[squirrel] Failed to compile '{}'", script);
        return false;
}

bool Squirrel::LoadScript(const std::string &script)
{
        return LoadScript(this->vm, script);
}

Squirrel::~Squirrel()
{
        this->Uninitialize();
}

void Squirrel::Uninitialize()
{
        ScriptAllocatorScope alloc_scope(this);

        /* Remove the delegation */
        sq_pushroottable(this->vm);
        sq_pushnull(this->vm);
        sq_setdelegate(this->vm, -2);
        sq_pop(this->vm, 1);

        /* Clean up the stuff */
        sq_pop(this->vm, 1);
        sq_close(this->vm);

        assert(this->allocator->allocated_size == 0);

        /* Reset memory allocation errors. */
        this->allocator->error_thrown = false;
}

void Squirrel::Reset()
{
        this->Uninitialize();
        this->Initialize();
}

void Squirrel::InsertResult(bool result)
{
        ScriptAllocatorScope alloc_scope(this);

        sq_pushbool(this->vm, result);
        if (this->IsSuspended()) { // Called before resuming a suspended script?
                vm->GetAt(vm->_stackbase + vm->_suspended_target) = vm->GetUp(-1);
                vm->Pop();
        }
}

void Squirrel::InsertResult(int result)
{
        ScriptAllocatorScope alloc_scope(this);

        sq_pushinteger(this->vm, result);
        if (this->IsSuspended()) { // Called before resuming a suspended script?
                vm->GetAt(vm->_stackbase + vm->_suspended_target) = vm->GetUp(-1);
                vm->Pop();
        }
}

/* static */ void Squirrel::DecreaseOps(HSQUIRRELVM vm, int ops)
{
        vm->DecreaseOps(ops);
}

bool Squirrel::IsSuspended()
{
        return this->vm->_suspended != 0;
}

bool Squirrel::HasScriptCrashed()
{
        return this->crashed;
}

void Squirrel::CrashOccurred()
{
        this->crashed = true;
}

bool Squirrel::CanSuspend()
{
        ScriptAllocatorScope alloc_scope(this);
        return sq_can_suspend(this->vm);
}

SQInteger Squirrel::GetOpsTillSuspend()
{
        return this->vm->_ops_till_suspend;
}