OpenTTD-patches/src/script/squirrel_helper.hpp
Michael Lutz ca3cb4d2ef Codechange: [Script] Use a class template instead of a function template for squirrel type conversion.
Class templates allow using partial template specialization, which is useful in
case one wants to have a type conversion on a type that is itself templated.
2023-02-24 21:46:27 +01:00

393 lines
16 KiB
C++

/*
* 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_helper.hpp declarations and parts of the implementation of the class for convert code */
#ifndef SQUIRREL_HELPER_HPP
#define SQUIRREL_HELPER_HPP
#include "squirrel.hpp"
#include "../core/smallvec_type.hpp"
#include "../economy_type.h"
#include "../string_func.h"
#include "../tile_type.h"
#include "squirrel_helper_type.hpp"
template <class CL, ScriptType ST> const char *GetClassName();
/**
* The Squirrel convert routines
*/
namespace SQConvert {
/**
* Pointers assigned to this class will be free'd when this instance
* comes out of scope. Useful to make sure you can use stredup(),
* without leaking memory.
*/
struct SQAutoFreePointers : std::vector<void *> {
~SQAutoFreePointers()
{
for (void * p : *this) free(p);
}
};
/**
* To return a value to squirrel, we use this helper class. It converts to the right format.
* We use a class instead of a plain function to allow us to use partial template specializations.
*/
template <typename T> struct Return;
template <> struct Return<uint8> { static inline int Set(HSQUIRRELVM vm, uint8 res) { sq_pushinteger(vm, (int32)res); return 1; } };
template <> struct Return<uint16> { static inline int Set(HSQUIRRELVM vm, uint16 res) { sq_pushinteger(vm, (int32)res); return 1; } };
template <> struct Return<uint32> { static inline int Set(HSQUIRRELVM vm, uint32 res) { sq_pushinteger(vm, (int32)res); return 1; } };
template <> struct Return<int8> { static inline int Set(HSQUIRRELVM vm, int8 res) { sq_pushinteger(vm, res); return 1; } };
template <> struct Return<int16> { static inline int Set(HSQUIRRELVM vm, int16 res) { sq_pushinteger(vm, res); return 1; } };
template <> struct Return<int32> { static inline int Set(HSQUIRRELVM vm, int32 res) { sq_pushinteger(vm, res); return 1; } };
template <> struct Return<int64> { static inline int Set(HSQUIRRELVM vm, int64 res) { sq_pushinteger(vm, res); return 1; } };
template <> struct Return<Money> { static inline int Set(HSQUIRRELVM vm, Money res) { sq_pushinteger(vm, res); return 1; } };
template <> struct Return<TileIndex> { static inline int Set(HSQUIRRELVM vm, TileIndex res) { sq_pushinteger(vm, (int32)res.value); return 1; } };
template <> struct Return<bool> { static inline int Set(HSQUIRRELVM vm, bool res) { sq_pushbool (vm, res); return 1; } };
template <> struct Return<char *> { static inline int Set(HSQUIRRELVM vm, char *res) { if (res == nullptr) sq_pushnull(vm); else { sq_pushstring(vm, res, -1); free(res); } return 1; } };
template <> struct Return<const char *> { static inline int Set(HSQUIRRELVM vm, const char *res) { if (res == nullptr) sq_pushnull(vm); else { sq_pushstring(vm, res, -1); } return 1; } };
template <> struct Return<void *> { static inline int Set(HSQUIRRELVM vm, void *res) { sq_pushuserpointer(vm, res); return 1; } };
template <> struct Return<HSQOBJECT> { static inline int Set(HSQUIRRELVM vm, HSQOBJECT res) { sq_pushobject(vm, res); return 1; } };
/**
* To get a param from squirrel, we use this helper class. It converts to the right format.
* We use a class instead of a plain function to allow us to use partial template specializations.
*/
template <typename T> struct Param;
template <> struct Param<uint8> { static inline uint8 Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return tmp; } };
template <> struct Param<uint16> { static inline uint16 Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return tmp; } };
template <> struct Param<uint32> { static inline uint32 Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return tmp; } };
template <> struct Param<int8> { static inline int8 Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return tmp; } };
template <> struct Param<int16> { static inline int16 Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return tmp; } };
template <> struct Param<int32> { static inline int32 Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return tmp; } };
template <> struct Param<int64> { static inline int64 Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return tmp; } };
template <> struct Param<TileIndex> { static inline TileIndex Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return TileIndex((uint32)(int32)tmp); } };
template <> struct Param<Money> { static inline Money Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQInteger tmp; sq_getinteger (vm, index, &tmp); return tmp; } };
template <> struct Param<bool> { static inline bool Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQBool tmp; sq_getbool (vm, index, &tmp); return tmp != 0; } };
template <> struct Param<void *> { static inline void *Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr) { SQUserPointer tmp; sq_getuserpointer(vm, index, &tmp); return tmp; } };
template <> struct Param<const char *> {
static inline const char *Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr)
{
/* Convert what-ever there is as parameter to a string */
sq_tostring(vm, index);
const SQChar *tmp;
sq_getstring(vm, -1, &tmp);
char *tmp_str = stredup(tmp);
sq_poptop(vm);
ptr->push_back((void *)tmp_str);
StrMakeValidInPlace(tmp_str);
return tmp_str;
}
};
template <> struct Param<Array *> {
static inline Array *Get(HSQUIRRELVM vm, int index, SQAutoFreePointers *ptr)
{
/* Sanity check of the size. */
if (sq_getsize(vm, index) > UINT16_MAX) throw sq_throwerror(vm, "an array used as parameter to a function is too large");
SQObject obj;
sq_getstackobj(vm, index, &obj);
sq_pushobject(vm, obj);
sq_pushnull(vm);
std::vector<int32> data;
while (SQ_SUCCEEDED(sq_next(vm, -2))) {
SQInteger tmp;
if (SQ_SUCCEEDED(sq_getinteger(vm, -1, &tmp))) {
data.push_back((int32)tmp);
} else {
sq_pop(vm, 4);
throw sq_throwerror(vm, "a member of an array used as parameter to a function is not numeric");
}
sq_pop(vm, 2);
}
sq_pop(vm, 2);
Array *arr = (Array *)MallocT<byte>(sizeof(Array) + sizeof(int32) * data.size());
arr->size = data.size();
memcpy(arr->array, data.data(), sizeof(int32) * data.size());
ptr->push_back(arr);
return arr;
}
};
/**
* Helper class to recognize the function type (retval type, args) and use the proper specialization
* for SQ callback. The partial specializations for the second arg (Tis_void_retval) are not possible
* on the function. Therefore the class is used instead.
*/
template <typename Tfunc> struct HelperT;
/**
* The real C++ caller for functions.
*/
template <typename Tretval, typename... Targs>
struct HelperT<Tretval (*)(Targs...)> {
static int SQCall(void *instance, Tretval(*func)(Targs...), HSQUIRRELVM vm)
{
return SQCall(instance, func, vm, std::index_sequence_for<Targs...>{});
}
private:
template <size_t... i>
static int SQCall(void *instance, Tretval(*func)(Targs...), [[maybe_unused]] HSQUIRRELVM vm, std::index_sequence<i...>)
{
[[maybe_unused]] SQAutoFreePointers ptr;
if constexpr (std::is_void_v<Tretval>) {
(*func)(
Param<Targs>::Get(vm, 2 + i, &ptr)...
);
return 0;
} else {
Tretval ret = (*func)(
Param<Targs>::Get(vm, 2 + i, &ptr)...
);
return Return<Tretval>::Set(vm, ret);
}
}
};
/**
* The real C++ caller for methods.
*/
template <class Tcls, typename Tretval, typename... Targs>
struct HelperT<Tretval(Tcls:: *)(Targs...)> {
static int SQCall(Tcls *instance, Tretval(Tcls:: *func)(Targs...), HSQUIRRELVM vm)
{
return SQCall(instance, func, vm, std::index_sequence_for<Targs...>{});
}
static Tcls *SQConstruct(Tcls *instance, Tretval(Tcls:: *func)(Targs...), HSQUIRRELVM vm)
{
return SQConstruct(instance, func, vm, std::index_sequence_for<Targs...>{});
}
private:
template <size_t... i>
static int SQCall(Tcls *instance, Tretval(Tcls:: *func)(Targs...), [[maybe_unused]] HSQUIRRELVM vm, std::index_sequence<i...>)
{
[[maybe_unused]] SQAutoFreePointers ptr;
if constexpr (std::is_void_v<Tretval>) {
(instance->*func)(
Param<Targs>::Get(vm, 2 + i, &ptr)...
);
return 0;
} else {
Tretval ret = (instance->*func)(
Param<Targs>::Get(vm, 2 + i, &ptr)...
);
return Return<Tretval>::Set(vm, ret);
}
}
template <size_t... i>
static Tcls *SQConstruct(Tcls *, Tretval(Tcls:: *func)(Targs...), [[maybe_unused]] HSQUIRRELVM vm, std::index_sequence<i...>)
{
[[maybe_unused]] SQAutoFreePointers ptr;
Tcls *inst = new Tcls(
Param<Targs>::Get(vm, 2 + i, &ptr)...
);
return inst;
}
};
/**
* A general template for all non-static method callbacks from Squirrel.
* In here the function_proc is recovered, and the SQCall is called that
* can handle this exact amount of params.
*/
template <typename Tcls, typename Tmethod, ScriptType Ttype>
inline SQInteger DefSQNonStaticCallback(HSQUIRRELVM vm)
{
/* Find the amount of params we got */
int nparam = sq_gettop(vm);
SQUserPointer ptr = nullptr;
SQUserPointer real_instance = nullptr;
HSQOBJECT instance;
/* Get the 'SQ' instance of this class */
Squirrel::GetInstance(vm, &instance);
/* Protect against calls to a non-static method in a static way */
sq_pushroottable(vm);
const char *className = GetClassName<Tcls, Ttype>();
sq_pushstring(vm, className, -1);
sq_get(vm, -2);
sq_pushobject(vm, instance);
if (sq_instanceof(vm) != SQTrue) return sq_throwerror(vm, "class method is non-static");
sq_pop(vm, 3);
/* Get the 'real' instance of this class */
sq_getinstanceup(vm, 1, &real_instance, nullptr);
/* Get the real function pointer */
sq_getuserdata(vm, nparam, &ptr, nullptr);
if (real_instance == nullptr) return sq_throwerror(vm, "couldn't detect real instance of class for non-static call");
/* Remove the userdata from the stack */
sq_pop(vm, 1);
try {
/* Delegate it to a template that can handle this specific function */
return HelperT<Tmethod>::SQCall((Tcls *)real_instance, *(Tmethod *)ptr, vm);
} catch (SQInteger &e) {
return e;
}
}
/**
* A general template for all non-static advanced method callbacks from Squirrel.
* In here the function_proc is recovered, and the SQCall is called that
* can handle this exact amount of params.
*/
template <typename Tcls, typename Tmethod, ScriptType Ttype>
inline SQInteger DefSQAdvancedNonStaticCallback(HSQUIRRELVM vm)
{
/* Find the amount of params we got */
int nparam = sq_gettop(vm);
SQUserPointer ptr = nullptr;
SQUserPointer real_instance = nullptr;
HSQOBJECT instance;
/* Get the 'SQ' instance of this class */
Squirrel::GetInstance(vm, &instance);
/* Protect against calls to a non-static method in a static way */
sq_pushroottable(vm);
const char *className = GetClassName<Tcls, Ttype>();
sq_pushstring(vm, className, -1);
sq_get(vm, -2);
sq_pushobject(vm, instance);
if (sq_instanceof(vm) != SQTrue) return sq_throwerror(vm, "class method is non-static");
sq_pop(vm, 3);
/* Get the 'real' instance of this class */
sq_getinstanceup(vm, 1, &real_instance, nullptr);
/* Get the real function pointer */
sq_getuserdata(vm, nparam, &ptr, nullptr);
if (real_instance == nullptr) return sq_throwerror(vm, "couldn't detect real instance of class for non-static call");
/* Remove the userdata from the stack */
sq_pop(vm, 1);
/* Call the function, which its only param is always the VM */
return (SQInteger)(((Tcls *)real_instance)->*(*(Tmethod *)ptr))(vm);
}
/**
* A general template for all function/static method callbacks from Squirrel.
* In here the function_proc is recovered, and the SQCall is called that
* can handle this exact amount of params.
*/
template <typename Tcls, typename Tmethod>
inline SQInteger DefSQStaticCallback(HSQUIRRELVM vm)
{
/* Find the amount of params we got */
int nparam = sq_gettop(vm);
SQUserPointer ptr = nullptr;
/* Get the real function pointer */
sq_getuserdata(vm, nparam, &ptr, nullptr);
try {
/* Delegate it to a template that can handle this specific function */
return HelperT<Tmethod>::SQCall((Tcls *)nullptr, *(Tmethod *)ptr, vm);
} catch (SQInteger &e) {
return e;
}
}
/**
* A general template for all static advanced method callbacks from Squirrel.
* In here the function_proc is recovered, and the SQCall is called that
* can handle this exact amount of params.
*/
template <typename Tcls, typename Tmethod>
inline SQInteger DefSQAdvancedStaticCallback(HSQUIRRELVM vm)
{
/* Find the amount of params we got */
int nparam = sq_gettop(vm);
SQUserPointer ptr = nullptr;
/* Get the real function pointer */
sq_getuserdata(vm, nparam, &ptr, nullptr);
/* Remove the userdata from the stack */
sq_pop(vm, 1);
/* Call the function, which its only param is always the VM */
return (SQInteger)(*(*(Tmethod *)ptr))(vm);
}
/**
* A general template for the destructor of SQ instances. This is needed
* here as it has to be in the same scope as DefSQConstructorCallback.
*/
template <typename Tcls>
static SQInteger DefSQDestructorCallback(SQUserPointer p, SQInteger size)
{
/* Remove the real instance too */
if (p != nullptr) ((Tcls *)p)->Release();
return 0;
}
/**
* A general template to handle creating of instance with any amount of
* params. It creates the instance in C++, and it sets all the needed
* settings in SQ to register the instance.
*/
template <typename Tcls, typename Tmethod, int Tnparam>
inline SQInteger DefSQConstructorCallback(HSQUIRRELVM vm)
{
try {
/* Create the real instance */
Tcls *instance = HelperT<Tmethod>::SQConstruct((Tcls *)nullptr, (Tmethod)nullptr, vm);
sq_setinstanceup(vm, -Tnparam, instance);
sq_setreleasehook(vm, -Tnparam, DefSQDestructorCallback<Tcls>);
instance->AddRef();
return 0;
} catch (SQInteger &e) {
return e;
}
}
/**
* A general template to handle creating of an instance with a complex
* constructor.
*/
template <typename Tcls>
inline SQInteger DefSQAdvancedConstructorCallback(HSQUIRRELVM vm)
{
try {
/* Find the amount of params we got */
int nparam = sq_gettop(vm);
/* Create the real instance */
Tcls *instance = new Tcls(vm);
sq_setinstanceup(vm, -nparam, instance);
sq_setreleasehook(vm, -nparam, DefSQDestructorCallback<Tcls>);
instance->AddRef();
return 0;
} catch (SQInteger &e) {
return e;
}
}
} // namespace SQConvert
#endif /* SQUIRREL_HELPER_HPP */