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modffi.c 16.58 KiB
/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2014 Paul Sokolovsky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <assert.h>
#include <string.h>
#include <errno.h>
#include <dlfcn.h>
#include <ffi.h>
#include <stdint.h>
#include "py/nlr.h"
#include "py/runtime.h"
#include "py/binary.h"
/*
* modffi uses character codes to encode a value type, based on "struct"
* module type codes, with some extensions and overridings.
*
* Extra/overridden typecodes:
* v - void, can be used only as return type
* P - const void*, pointer to read-only memory
* p - void*, meaning pointer to a writable memory (note that this
* clashes with struct's "p" as "Pascal string").
* s - as argument, the same as "p", as return value, causes string
* to be allocated and returned, instead of pointer value.
* O - mp_obj_t, passed as is (mostly useful as a callback param)
*
* TODO:
* C - callback function
*
* Note: all constraint specified by typecode can be not enforced at this time,
* but may be later.
*/
typedef struct _mp_obj_opaque_t {
mp_obj_base_t base;
void *val;
} mp_obj_opaque_t;
typedef struct _mp_obj_ffimod_t {
mp_obj_base_t base;
void *handle;
} mp_obj_ffimod_t;
typedef struct _mp_obj_ffivar_t {
mp_obj_base_t base; void *var;
char type;
// ffi_type *type;
} mp_obj_ffivar_t;
typedef struct _mp_obj_ffifunc_t {
mp_obj_base_t base;
void *func;
char rettype;
const char *argtypes;
ffi_cif cif;
ffi_type *params[];
} mp_obj_ffifunc_t;
typedef struct _mp_obj_fficallback_t {
mp_obj_base_t base;
void *func;
ffi_closure *clo;
char rettype;
ffi_cif cif;
ffi_type *params[];
} mp_obj_fficallback_t;
//STATIC const mp_obj_type_t opaque_type;
STATIC const mp_obj_type_t ffimod_type;
STATIC const mp_obj_type_t ffifunc_type;
STATIC const mp_obj_type_t fficallback_type;
STATIC const mp_obj_type_t ffivar_type;
STATIC ffi_type *char2ffi_type(char c)
{
switch (c) {
case 'b': return &ffi_type_schar;
case 'B': return &ffi_type_uchar;
case 'h': return &ffi_type_sshort;
case 'H': return &ffi_type_ushort;
case 'i': return &ffi_type_sint;
case 'I': return &ffi_type_uint;
case 'l': return &ffi_type_slong;
case 'L': return &ffi_type_ulong;
#if MICROPY_PY_BUILTINS_FLOAT
case 'f': return &ffi_type_float;
case 'd': return &ffi_type_double;
#endif
case 'O': // mp_obj_t
case 'C': // (*)()
case 'P': // const void*
case 'p': // void*
case 's': return &ffi_type_pointer;
case 'v': return &ffi_type_void;
default: return NULL;
}
}
STATIC ffi_type *get_ffi_type(mp_obj_t o_in)
{
if (MP_OBJ_IS_STR(o_in)) {
mp_uint_t len;
const char *s = mp_obj_str_get_data(o_in, &len);
ffi_type *t = char2ffi_type(*s);
if (t != NULL) {
return t;
}
}
// TODO: Support actual libffi type objects
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "Unknown type"));
}
STATIC mp_obj_t return_ffi_value(ffi_arg val, char type){
switch (type) {
case 's': {
const char *s = (const char *)(intptr_t)val;
if (!s) {
return mp_const_none;
}
return mp_obj_new_str(s, strlen(s), false);
}
case 'v':
return mp_const_none;
#if MICROPY_PY_BUILTINS_FLOAT
case 'f': {
union { ffi_arg ffi; float flt; } val_union = { .ffi = val };
return mp_obj_new_float(val_union.flt);
}
case 'd': {
double *p = (double*)&val;
return mp_obj_new_float(*p);
}
#endif
case 'O':
return (mp_obj_t)(intptr_t)val;
default:
return mp_obj_new_int(val);
}
}
// FFI module
STATIC void ffimod_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
(void)kind;
mp_obj_ffimod_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "<ffimod %p>", self->handle);
}
STATIC mp_obj_t ffimod_close(mp_obj_t self_in) {
mp_obj_ffimod_t *self = MP_OBJ_TO_PTR(self_in);
dlclose(self->handle);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(ffimod_close_obj, ffimod_close);
STATIC mp_obj_t make_func(mp_obj_t rettype_in, void *func, mp_obj_t argtypes_in) {
const char *rettype = mp_obj_str_get_str(rettype_in);
const char *argtypes = mp_obj_str_get_str(argtypes_in);
mp_int_t nparams = MP_OBJ_SMALL_INT_VALUE(mp_obj_len_maybe(argtypes_in));
mp_obj_ffifunc_t *o = m_new_obj_var(mp_obj_ffifunc_t, ffi_type*, nparams);
o->base.type = &ffifunc_type;
o->func = func;
o->rettype = *rettype;
o->argtypes = argtypes;
mp_obj_t iterable = mp_getiter(argtypes_in);
mp_obj_t item;
int i = 0;
while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
o->params[i++] = get_ffi_type(item);
}
int res = ffi_prep_cif(&o->cif, FFI_DEFAULT_ABI, nparams, char2ffi_type(*rettype), o->params);
if (res != FFI_OK) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Error in ffi_prep_cif"));
}
return MP_OBJ_FROM_PTR(o);
}
STATIC mp_obj_t ffimod_func(size_t n_args, const mp_obj_t *args) {
(void)n_args; // always 4
mp_obj_ffimod_t *self = MP_OBJ_TO_PTR(args[0]);
const char *symname = mp_obj_str_get_str(args[2]);
void *sym = dlsym(self->handle, symname);
if (sym == NULL) {
nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(ENOENT)));
}
return make_func(args[1], sym, args[3]);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(ffimod_func_obj, 4, 4, ffimod_func);
STATIC mp_obj_t mod_ffi_func(mp_obj_t rettype, mp_obj_t addr_in, mp_obj_t argtypes) {
void *addr = (void*)MP_OBJ_TO_PTR(mp_obj_int_get_truncated(addr_in));
return make_func(rettype, addr, argtypes);
}
MP_DEFINE_CONST_FUN_OBJ_3(mod_ffi_func_obj, mod_ffi_func);
STATIC void call_py_func(ffi_cif *cif, void *ret, void** args, void *func) {
mp_obj_t pyargs[cif->nargs];
for (uint i = 0; i < cif->nargs; i++) {
pyargs[i] = mp_obj_new_int(*(mp_int_t*)args[i]);
}
mp_obj_t res = mp_call_function_n_kw(MP_OBJ_FROM_PTR(func), cif->nargs, 0, pyargs);
if (res != mp_const_none) {
*(ffi_arg*)ret = mp_obj_int_get_truncated(res);
}
}
STATIC mp_obj_t mod_ffi_callback(mp_obj_t rettype_in, mp_obj_t func_in, mp_obj_t paramtypes_in) {
const char *rettype = mp_obj_str_get_str(rettype_in);
mp_int_t nparams = MP_OBJ_SMALL_INT_VALUE(mp_obj_len_maybe(paramtypes_in));
mp_obj_fficallback_t *o = m_new_obj_var(mp_obj_fficallback_t, ffi_type*, nparams);
o->base.type = &fficallback_type;
o->clo = ffi_closure_alloc(sizeof(ffi_closure), &o->func);
o->rettype = *rettype;
mp_obj_t iterable = mp_getiter(paramtypes_in);
mp_obj_t item;
int i = 0;
while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
o->params[i++] = get_ffi_type(item);
}
int res = ffi_prep_cif(&o->cif, FFI_DEFAULT_ABI, nparams, char2ffi_type(*rettype), o->params);
if (res != FFI_OK) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Error in ffi_prep_cif"));
}
res = ffi_prep_closure_loc(o->clo, &o->cif, call_py_func, MP_OBJ_TO_PTR(func_in), o->func);
if (res != FFI_OK) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "ffi_prep_closure_loc"));
}
return MP_OBJ_FROM_PTR(o);
}
MP_DEFINE_CONST_FUN_OBJ_3(mod_ffi_callback_obj, mod_ffi_callback);
STATIC mp_obj_t ffimod_var(mp_obj_t self_in, mp_obj_t vartype_in, mp_obj_t symname_in) {
mp_obj_ffimod_t *self = MP_OBJ_TO_PTR(self_in);
const char *rettype = mp_obj_str_get_str(vartype_in);
const char *symname = mp_obj_str_get_str(symname_in);
void *sym = dlsym(self->handle, symname);
if (sym == NULL) { nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(ENOENT)));
}
mp_obj_ffivar_t *o = m_new_obj(mp_obj_ffivar_t);
o->base.type = &ffivar_type;
o->var = sym;
o->type = *rettype;
return MP_OBJ_FROM_PTR(o);
}
MP_DEFINE_CONST_FUN_OBJ_3(ffimod_var_obj, ffimod_var);
STATIC mp_obj_t ffimod_addr(mp_obj_t self_in, mp_obj_t symname_in) {
mp_obj_ffimod_t *self = MP_OBJ_TO_PTR(self_in);
const char *symname = mp_obj_str_get_str(symname_in);
void *sym = dlsym(self->handle, symname);
if (sym == NULL) {
nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(ENOENT)));
}
return mp_obj_new_int((uintptr_t)sym);
}
MP_DEFINE_CONST_FUN_OBJ_2(ffimod_addr_obj, ffimod_addr);
STATIC mp_obj_t ffimod_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
(void)n_args;
(void)n_kw;
const char *fname = NULL;
if (args[0] != mp_const_none) {
fname = mp_obj_str_get_str(args[0]);
}
void *mod = dlopen(fname, RTLD_NOW | RTLD_LOCAL);
if (mod == NULL) {
nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(errno)));
}
mp_obj_ffimod_t *o = m_new_obj(mp_obj_ffimod_t);
o->base.type = type;
o->handle = mod;
return MP_OBJ_FROM_PTR(o);
}
STATIC const mp_rom_map_elem_t ffimod_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_func), MP_ROM_PTR(&ffimod_func_obj) },
{ MP_ROM_QSTR(MP_QSTR_var), MP_ROM_PTR(&ffimod_var_obj) },
{ MP_ROM_QSTR(MP_QSTR_addr), MP_ROM_PTR(&ffimod_addr_obj) },
{ MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&ffimod_close_obj) },
};
STATIC MP_DEFINE_CONST_DICT(ffimod_locals_dict, ffimod_locals_dict_table);
STATIC const mp_obj_type_t ffimod_type = {
{ &mp_type_type },
.name = MP_QSTR_ffimod,
.print = ffimod_print,
.make_new = ffimod_make_new,
.locals_dict = (mp_obj_dict_t*)&ffimod_locals_dict,
};
// FFI function
STATIC void ffifunc_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
(void)kind;
mp_obj_ffifunc_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "<ffifunc %p>", self->func);
}
STATIC mp_obj_t ffifunc_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
mp_obj_ffifunc_t *self = MP_OBJ_TO_PTR(self_in);
assert(n_kw == 0); assert(n_args == self->cif.nargs);
ffi_arg values[n_args];
void *valueptrs[n_args];
const char *argtype = self->argtypes;
for (uint i = 0; i < n_args; i++, argtype++) {
mp_obj_t a = args[i];
if (*argtype == 'O') {
values[i] = (ffi_arg)(intptr_t)a;
#if MICROPY_PY_BUILTINS_FLOAT
} else if (*argtype == 'f') {
float *p = (float*)&values[i];
*p = mp_obj_get_float(a);
} else if (*argtype == 'd') {
double *p = (double*)&values[i];
*p = mp_obj_get_float(a);
#endif
} else if (a == mp_const_none) {
values[i] = 0;
} else if (MP_OBJ_IS_INT(a)) {
values[i] = mp_obj_int_get_truncated(a);
} else if (MP_OBJ_IS_STR(a)) {
const char *s = mp_obj_str_get_str(a);
values[i] = (ffi_arg)(intptr_t)s;
} else if (((mp_obj_base_t*)MP_OBJ_TO_PTR(a))->type->buffer_p.get_buffer != NULL) {
mp_obj_base_t *o = (mp_obj_base_t*)MP_OBJ_TO_PTR(a);
mp_buffer_info_t bufinfo;
int ret = o->type->buffer_p.get_buffer(MP_OBJ_FROM_PTR(o), &bufinfo, MP_BUFFER_READ); // TODO: MP_BUFFER_READ?
if (ret != 0) {
goto error;
}
values[i] = (ffi_arg)(intptr_t)bufinfo.buf;
} else if (MP_OBJ_IS_TYPE(a, &fficallback_type)) {
mp_obj_fficallback_t *p = MP_OBJ_TO_PTR(a);
values[i] = (ffi_arg)(intptr_t)p->func;
} else {
goto error;
}
valueptrs[i] = &values[i];
}
// If ffi_arg is not big enough to hold a double, then we must pass along a
// pointer to a memory location of the correct size.
// TODO check if this needs to be done for other types which don't fit into
// ffi_arg.
#if MICROPY_PY_BUILTINS_FLOAT
if (sizeof(ffi_arg) == 4 && self->rettype == 'd') {
double retval;
ffi_call(&self->cif, self->func, &retval, valueptrs);
return mp_obj_new_float(retval);
} else
#endif
{
ffi_arg retval;
ffi_call(&self->cif, self->func, &retval, valueptrs);
return return_ffi_value(retval, self->rettype);
}
error:
nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "Don't know how to pass object to native function"));
}
STATIC const mp_obj_type_t ffifunc_type = {
{ &mp_type_type },
.name = MP_QSTR_ffifunc,
.print = ffifunc_print,
.call = ffifunc_call,
};
// FFI callback for Python function
STATIC void fficallback_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
(void)kind;
mp_obj_fficallback_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "<fficallback %p>", self->func);
}
STATIC const mp_obj_type_t fficallback_type = {
{ &mp_type_type },
.name = MP_QSTR_fficallback,
.print = fficallback_print,
};
// FFI variable
STATIC void ffivar_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
(void)kind;
mp_obj_ffivar_t *self = MP_OBJ_TO_PTR(self_in);
// Variable value printed as cast to int
mp_printf(print, "<ffivar @%p: 0x%x>", self->var, *(int*)self->var);
}
STATIC mp_obj_t ffivar_get(mp_obj_t self_in) {
mp_obj_ffivar_t *self = MP_OBJ_TO_PTR(self_in);
return mp_binary_get_val_array(self->type, self->var, 0);
}
MP_DEFINE_CONST_FUN_OBJ_1(ffivar_get_obj, ffivar_get);
STATIC mp_obj_t ffivar_set(mp_obj_t self_in, mp_obj_t val_in) {
mp_obj_ffivar_t *self = MP_OBJ_TO_PTR(self_in);
mp_binary_set_val_array(self->type, self->var, 0, val_in);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(ffivar_set_obj, ffivar_set);
STATIC const mp_rom_map_elem_t ffivar_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_get), MP_ROM_PTR(&ffivar_get_obj) },
{ MP_ROM_QSTR(MP_QSTR_set), MP_ROM_PTR(&ffivar_set_obj) },
};
STATIC MP_DEFINE_CONST_DICT(ffivar_locals_dict, ffivar_locals_dict_table);
STATIC const mp_obj_type_t ffivar_type = {
{ &mp_type_type },
.name = MP_QSTR_ffivar,
.print = ffivar_print,
.locals_dict = (mp_obj_dict_t*)&ffivar_locals_dict,
};
// Generic opaque storage object (unused)
/*
STATIC const mp_obj_type_t opaque_type = {
{ &mp_type_type },
.name = MP_QSTR_opaqueval,
// .print = opaque_print,
};
*/
STATIC mp_obj_t mod_ffi_open(size_t n_args, const mp_obj_t *args) {
return ffimod_make_new(&ffimod_type, n_args, 0, args);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_ffi_open_obj, 1, 2, mod_ffi_open);
STATIC mp_obj_t mod_ffi_as_bytearray(mp_obj_t ptr, mp_obj_t size) {
return mp_obj_new_bytearray_by_ref(mp_obj_int_get_truncated(size), (void*)(uintptr_t)mp_obj_int_get_truncated(ptr));
}
MP_DEFINE_CONST_FUN_OBJ_2(mod_ffi_as_bytearray_obj, mod_ffi_as_bytearray);
STATIC const mp_rom_map_elem_t mp_module_ffi_globals_table[] = { { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_ffi) },
{ MP_ROM_QSTR(MP_QSTR_open), MP_ROM_PTR(&mod_ffi_open_obj) },
{ MP_ROM_QSTR(MP_QSTR_callback), MP_ROM_PTR(&mod_ffi_callback_obj) },
{ MP_ROM_QSTR(MP_QSTR_func), MP_ROM_PTR(&mod_ffi_func_obj) },
{ MP_ROM_QSTR(MP_QSTR_as_bytearray), MP_ROM_PTR(&mod_ffi_as_bytearray_obj) },
};
STATIC MP_DEFINE_CONST_DICT(mp_module_ffi_globals, mp_module_ffi_globals_table);
const mp_obj_module_t mp_module_ffi = {
.base = { &mp_type_module },
.name = MP_QSTR_ffi,
.globals = (mp_obj_dict_t*)&mp_module_ffi_globals,
};