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guile/libguile/foreign.c
Ludovic Courtès 01ad5a7ba9 Raise an error when attempting to modify the value of `%null-pointer'. 
* libguile/foreign.c (sym_null_pointer_error): New variable.
  (null_pointer_error): New function.
  (scm_foreign_set_x): Raise an error if attempting to modify
  NULL_POINTER.
  (scm_foreign_to_bytevector): Use `null_pointer_error ()' instead of
  `scm_misc_error ()'.

* test-suite/tests/foreign.test: New file.

* test-suite/Makefile.am (SCM_TESTS): Add tests/foreign.test.

* test-suite/lib.scm (exception:null-pointer-error): New variable.
2010-04-09 00:32:15 +02:00

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/* Copyright (C) 2010 Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 3 of
* the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <ffi.h>
#include <alignof.h>
#include <string.h>
#include "libguile/_scm.h"
#include "libguile/bytevectors.h"
#include "libguile/instructions.h"
#include "libguile/foreign.h"
SCM_SYMBOL (sym_void, "void");
SCM_SYMBOL (sym_float, "float");
SCM_SYMBOL (sym_double, "double");
SCM_SYMBOL (sym_uint8, "uint8");
SCM_SYMBOL (sym_int8, "int8");
SCM_SYMBOL (sym_uint16, "uint16");
SCM_SYMBOL (sym_int16, "int16");
SCM_SYMBOL (sym_uint32, "uint32");
SCM_SYMBOL (sym_int32, "int32");
SCM_SYMBOL (sym_uint64, "uint64");
SCM_SYMBOL (sym_int64, "int64");
SCM_SYMBOL (sym_int, "int");
SCM_SYMBOL (sym_long, "long");
SCM_SYMBOL (sym_unsigned_int, "unsigned-int");
SCM_SYMBOL (sym_unsigned_long, "unsigned-long");
SCM_SYMBOL (sym_size_t, "size_t");
/* that's for pointers, you know. */
SCM_SYMBOL (sym_asterisk, "*");
SCM_SYMBOL (sym_null, "%null-pointer");
SCM_SYMBOL (sym_null_pointer_error, "null-pointer-error");
/* The cell representing the null pointer. */
static const scm_t_bits null_pointer[2] =
{
scm_tc7_foreign | (SCM_FOREIGN_TYPE_VOID << 8UL),
0
};
/* Raise a null pointer dereference error. */
static void
null_pointer_error (const char *func_name)
{
scm_error (sym_null_pointer_error, func_name,
"null pointer dereference", SCM_EOL, SCM_EOL);
}
static SCM cif_to_procedure (SCM cif, SCM func_ptr);
static SCM foreign_weak_refs = SCM_BOOL_F;
static void
register_weak_reference (SCM from, SCM to)
{
scm_hashq_set_x (foreign_weak_refs, from, to);
}
static void
foreign_finalizer_trampoline (GC_PTR ptr, GC_PTR data)
{
scm_t_foreign_finalizer finalizer = data;
finalizer (SCM_FOREIGN_POINTER (PTR2SCM (ptr), void));
}
SCM
scm_take_foreign_pointer (scm_t_foreign_type type, void *ptr, size_t len,
scm_t_foreign_finalizer finalizer)
{
SCM ret;
scm_t_bits word0;
word0 = (scm_t_bits)(scm_tc7_foreign | (type<<8)
| (finalizer ? (1<<16) : 0) | (len<<17));
if (SCM_UNLIKELY ((word0 >> 17) != len))
scm_out_of_range ("scm_take_foreign_pointer", scm_from_size_t (len));
ret = scm_cell (word0, (scm_t_bits) ptr);
if (finalizer)
{
/* Register a finalizer for the newly created instance. */
GC_finalization_proc prev_finalizer;
GC_PTR prev_finalizer_data;
GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (ret),
foreign_finalizer_trampoline,
finalizer,
&prev_finalizer,
&prev_finalizer_data);
}
return ret;
}
SCM_DEFINE (scm_foreign_ref, "foreign-ref", 1, 0, 0,
(SCM foreign),
"Reference the foreign value pointed to by @var{foreign}.\n\n"
"The value will be referenced according to its type.")
#define FUNC_NAME s_scm_foreign_ref
{
scm_t_foreign_type ftype;
scm_t_uint8 *ptr;
SCM_VALIDATE_FOREIGN (1, foreign);
ptr = SCM_FOREIGN_POINTER (foreign, scm_t_uint8);
ftype = SCM_FOREIGN_TYPE (foreign);
/* FIXME: is there a window in which we can see ptr but not foreign? */
/* FIXME: accessing unaligned pointers */
switch (ftype)
{
case SCM_FOREIGN_TYPE_VOID:
return scm_from_ulong ((unsigned long)ptr);
case SCM_FOREIGN_TYPE_FLOAT:
return scm_from_double (*(float*)ptr);
case SCM_FOREIGN_TYPE_DOUBLE:
return scm_from_double (*(double*)ptr);
case SCM_FOREIGN_TYPE_UINT8:
return scm_from_uint8 (*(scm_t_uint8*)ptr);
case SCM_FOREIGN_TYPE_INT8:
return scm_from_int8 (*(scm_t_int8*)ptr);
case SCM_FOREIGN_TYPE_UINT16:
return scm_from_uint16 (*(scm_t_uint16*)ptr);
case SCM_FOREIGN_TYPE_INT16:
return scm_from_int16 (*(scm_t_int16*)ptr);
case SCM_FOREIGN_TYPE_UINT32:
return scm_from_uint32 (*(scm_t_uint32*)ptr);
case SCM_FOREIGN_TYPE_INT32:
return scm_from_int32 (*(scm_t_int32*)ptr);
case SCM_FOREIGN_TYPE_UINT64:
return scm_from_uint64 (*(scm_t_uint64*)ptr);
case SCM_FOREIGN_TYPE_INT64:
return scm_from_int64 (*(scm_t_int64*)ptr);
default:
scm_wrong_type_arg_msg (FUNC_NAME, 1, foreign, "foreign");
}
}
#undef FUNC_NAME
SCM_DEFINE (scm_foreign_set_x, "foreign-set!", 2, 0, 0,
(SCM foreign, SCM val),
"Set the foreign value pointed to by @var{foreign}.\n\n"
"The value will be set according to its type.")
#define FUNC_NAME s_scm_foreign_set_x
{
scm_t_foreign_type ftype;
scm_t_uint8 *ptr;
SCM_VALIDATE_FOREIGN (1, foreign);
if (SCM_UNLIKELY (scm_is_eq (foreign, PTR2SCM (&null_pointer))))
/* Attempting to modify the pointer value of NULL_POINTER (which is
read-only anyway), so raise an error. */
null_pointer_error (FUNC_NAME);
ptr = SCM_FOREIGN_POINTER (foreign, scm_t_uint8);
ftype = SCM_FOREIGN_TYPE (foreign);
/* FIXME: is there a window in which we can see ptr but not foreign? */
/* FIXME: unaligned access */
switch (ftype)
{
case SCM_FOREIGN_TYPE_VOID:
SCM_SET_CELL_WORD_1 (foreign, scm_to_ulong (val));
break;
case SCM_FOREIGN_TYPE_FLOAT:
*(float*)ptr = scm_to_double (val);
break;
case SCM_FOREIGN_TYPE_DOUBLE:
*(double*)ptr = scm_to_double (val);
break;
case SCM_FOREIGN_TYPE_UINT8:
*(scm_t_uint8*)ptr = scm_to_uint8 (val);
break;
case SCM_FOREIGN_TYPE_INT8:
*(scm_t_int8*)ptr = scm_to_int8 (val);
break;
case SCM_FOREIGN_TYPE_UINT16:
*(scm_t_uint16*)ptr = scm_to_uint16 (val);
break;
case SCM_FOREIGN_TYPE_INT16:
*(scm_t_int16*)ptr = scm_to_int16 (val);
break;
case SCM_FOREIGN_TYPE_UINT32:
*(scm_t_uint32*)ptr = scm_to_uint32 (val);
break;
case SCM_FOREIGN_TYPE_INT32:
*(scm_t_int32*)ptr = scm_to_int32 (val);
break;
case SCM_FOREIGN_TYPE_UINT64:
*(scm_t_uint64*)ptr = scm_to_uint64 (val);
break;
case SCM_FOREIGN_TYPE_INT64:
*(scm_t_int64*)ptr = scm_to_int64 (val);
break;
default:
scm_wrong_type_arg_msg (FUNC_NAME, 1, val, "foreign");
}
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
SCM_DEFINE (scm_foreign_to_bytevector, "foreign->bytevector", 1, 3, 0,
(SCM foreign, SCM uvec_type, SCM offset, SCM len),
"Return a bytevector aliasing the memory pointed to by\n"
"@var{foreign}.\n\n"
"@var{foreign} must be a void pointer, a foreign whose type is\n"
"@var{void}. By default, the resulting bytevector will alias\n"
"all of the memory pointed to by @var{foreign}, from beginning\n"
"to end, treated as a @code{vu8} array.\n\n"
"The user may specify an alternate default interpretation for\n"
"the memory by passing the @var{uvec_type} argument, to indicate\n"
"that the memory is an array of elements of that type.\n"
"@var{uvec_type} should be something that\n"
"@code{uniform-vector-element-type} would return, like @code{f32}\n"
"or @code{s16}.\n\n"
"Users may also specify that the bytevector should only alias a\n"
"subset of the memory, by specifying @var{offset} and @var{len}\n"
"arguments.")
#define FUNC_NAME s_scm_foreign_to_bytevector
{
SCM ret;
scm_t_int8 *ptr;
size_t boffset, blen;
scm_t_array_element_type btype;
SCM_VALIDATE_FOREIGN_TYPED (1, foreign, VOID);
ptr = SCM_FOREIGN_POINTER (foreign, scm_t_int8);
if (SCM_UNLIKELY (ptr == NULL))
null_pointer_error (FUNC_NAME);
if (SCM_UNBNDP (uvec_type))
btype = SCM_ARRAY_ELEMENT_TYPE_VU8;
else
{
int i;
for (i = 0; i <= SCM_ARRAY_ELEMENT_TYPE_LAST; i++)
if (scm_is_eq (uvec_type, scm_i_array_element_types[i]))
break;
switch (i)
{
case SCM_ARRAY_ELEMENT_TYPE_VU8:
case SCM_ARRAY_ELEMENT_TYPE_U8:
case SCM_ARRAY_ELEMENT_TYPE_S8:
case SCM_ARRAY_ELEMENT_TYPE_U16:
case SCM_ARRAY_ELEMENT_TYPE_S16:
case SCM_ARRAY_ELEMENT_TYPE_U32:
case SCM_ARRAY_ELEMENT_TYPE_S32:
case SCM_ARRAY_ELEMENT_TYPE_U64:
case SCM_ARRAY_ELEMENT_TYPE_S64:
case SCM_ARRAY_ELEMENT_TYPE_F32:
case SCM_ARRAY_ELEMENT_TYPE_F64:
case SCM_ARRAY_ELEMENT_TYPE_C32:
case SCM_ARRAY_ELEMENT_TYPE_C64:
btype = i;
break;
default:
scm_wrong_type_arg_msg (FUNC_NAME, SCM_ARG1, uvec_type,
"uniform vector type");
}
}
if (SCM_UNBNDP (offset))
boffset = 0;
else if (SCM_FOREIGN_LEN (foreign))
boffset = scm_to_unsigned_integer (offset, 0,
SCM_FOREIGN_LEN (foreign) - 1);
else
boffset = scm_to_size_t (offset);
if (SCM_UNBNDP (len))
{
if (SCM_FOREIGN_LEN (foreign))
blen = SCM_FOREIGN_LEN (foreign) - boffset;
else
scm_misc_error (FUNC_NAME,
"length needed to convert foreign pointer to bytevector",
SCM_EOL);
}
else
{
if (SCM_FOREIGN_LEN (foreign))
blen = scm_to_unsigned_integer (len, 0,
SCM_FOREIGN_LEN (foreign) - boffset);
else
blen = scm_to_size_t (len);
}
ret = scm_c_take_typed_bytevector (ptr + boffset, blen, btype);
register_weak_reference (ret, foreign);
return ret;
}
#undef FUNC_NAME
SCM_DEFINE (scm_bytevector_to_foreign, "bytevector->foreign", 1, 2, 0,
(SCM bv, SCM offset, SCM len),
"Return a foreign pointer aliasing the memory pointed to by\n"
"@var{bv}.\n\n"
"The resulting foreign will be a void pointer, a foreign whose\n"
"type is @code{void}. By default it will alias all of the\n"
"memory pointed to by @var{bv}, from beginning to end.\n\n"
"Users may explicily specify that the foreign should only alias a\n"
"subset of the memory, by specifying @var{offset} and @var{len}\n"
"arguments.")
#define FUNC_NAME s_scm_bytevector_to_foreign
{
SCM ret;
scm_t_int8 *ptr;
size_t boffset, blen;
SCM_VALIDATE_BYTEVECTOR (1, bv);
ptr = SCM_BYTEVECTOR_CONTENTS (bv);
if (SCM_UNBNDP (offset))
boffset = 0;
else
boffset = scm_to_unsigned_integer (offset, 0,
SCM_BYTEVECTOR_LENGTH (bv) - 1);
if (SCM_UNBNDP (len))
blen = SCM_BYTEVECTOR_LENGTH (bv) - boffset;
else
blen = scm_to_unsigned_integer (len, 0,
SCM_BYTEVECTOR_LENGTH (bv) - boffset);
ret = scm_take_foreign_pointer (SCM_FOREIGN_TYPE_VOID, ptr + boffset, blen,
NULL);
register_weak_reference (ret, bv);
return ret;
}
#undef FUNC_NAME
SCM_DEFINE (scm_foreign_set_finalizer_x, "foreign-set-finalizer!", 2, 0, 0,
(SCM foreign, SCM finalizer),
"Arrange for the C procedure wrapped by @var{finalizer} to be\n"
"called on the pointer wrapped by @var{foreign} when @var{foreign}\n"
"becomes unreachable. Note: the C procedure should not call into\n"
"Scheme. If you need a Scheme finalizer, use guardians.")
#define FUNC_NAME s_scm_foreign_set_finalizer_x
{
void *c_finalizer;
GC_finalization_proc prev_finalizer;
GC_PTR prev_finalizer_data;
SCM_VALIDATE_FOREIGN_TYPED (1, foreign, VOID);
SCM_VALIDATE_FOREIGN_TYPED (2, finalizer, VOID);
c_finalizer = SCM_FOREIGN_POINTER (finalizer, void);
SCM_SET_CELL_WORD_0 (foreign, SCM_CELL_WORD_0 (foreign) | (1<<16));
GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (foreign),
foreign_finalizer_trampoline,
c_finalizer,
&prev_finalizer,
&prev_finalizer_data);
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
void
scm_i_foreign_print (SCM foreign, SCM port, scm_print_state *pstate)
{
scm_puts ("#<foreign ", port);
switch (SCM_FOREIGN_TYPE (foreign))
{
case SCM_FOREIGN_TYPE_FLOAT:
scm_puts ("float ", port);
break;
case SCM_FOREIGN_TYPE_DOUBLE:
scm_puts ("double ", port);
break;
case SCM_FOREIGN_TYPE_UINT8:
scm_puts ("uint8 ", port);
break;
case SCM_FOREIGN_TYPE_INT8:
scm_puts ("int8 ", port);
break;
case SCM_FOREIGN_TYPE_UINT16:
scm_puts ("uint16 ", port);
break;
case SCM_FOREIGN_TYPE_INT16:
scm_puts ("int16 ", port);
break;
case SCM_FOREIGN_TYPE_UINT32:
scm_puts ("uint32 ", port);
break;
case SCM_FOREIGN_TYPE_INT32:
scm_puts ("int32 ", port);
break;
case SCM_FOREIGN_TYPE_UINT64:
scm_puts ("uint64 ", port);
break;
case SCM_FOREIGN_TYPE_INT64:
scm_puts ("int64 ", port);
break;
case SCM_FOREIGN_TYPE_VOID:
scm_puts ("pointer ", port);
break;
default:
scm_wrong_type_arg_msg ("%print-foreign", 1, foreign, "foreign");
}
scm_display (scm_foreign_ref (foreign), port);
scm_putc ('>', port);
}
#define ROUND_UP(len,align) (align?(((len-1)|(align-1))+1):len)
SCM_DEFINE (scm_alignof, "alignof", 1, 0, 0, (SCM type),
"Return the alignment of @var{type}, in bytes.\n\n"
"@var{type} should be a valid C type, like @code{int}.\n"
"Alternately @var{type} may be the symbol @code{*}, in which\n"
"case the alignment of a pointer is returned. @var{type} may\n"
"also be a list of types, in which case the alignment of a\n"
"@code{struct} with ABI-conventional packing is returned.")
#define FUNC_NAME s_scm_alignof
{
if (SCM_I_INUMP (type))
{
switch (SCM_I_INUM (type))
{
case SCM_FOREIGN_TYPE_FLOAT:
return scm_from_size_t (alignof (float));
case SCM_FOREIGN_TYPE_DOUBLE:
return scm_from_size_t (alignof (double));
case SCM_FOREIGN_TYPE_UINT8:
return scm_from_size_t (alignof (scm_t_uint8));
case SCM_FOREIGN_TYPE_INT8:
return scm_from_size_t (alignof (scm_t_int8));
case SCM_FOREIGN_TYPE_UINT16:
return scm_from_size_t (alignof (scm_t_uint16));
case SCM_FOREIGN_TYPE_INT16:
return scm_from_size_t (alignof (scm_t_int16));
case SCM_FOREIGN_TYPE_UINT32:
return scm_from_size_t (alignof (scm_t_uint32));
case SCM_FOREIGN_TYPE_INT32:
return scm_from_size_t (alignof (scm_t_int32));
case SCM_FOREIGN_TYPE_UINT64:
return scm_from_size_t (alignof (scm_t_uint64));
case SCM_FOREIGN_TYPE_INT64:
return scm_from_size_t (alignof (scm_t_int64));
default:
scm_wrong_type_arg (FUNC_NAME, 1, type);
}
}
else if (scm_is_eq (type, sym_asterisk))
/* a pointer */
return scm_from_size_t (alignof (void*));
else if (scm_is_pair (type))
/* a struct, yo */
return scm_alignof (scm_car (type));
else
scm_wrong_type_arg (FUNC_NAME, 1, type);
}
#undef FUNC_NAME
SCM_DEFINE (scm_sizeof, "sizeof", 1, 0, 0, (SCM type),
"Return the size of @var{type}, in bytes.\n\n"
"@var{type} should be a valid C type, like @code{int}.\n"
"Alternately @var{type} may be the symbol @code{*}, in which\n"
"case the size of a pointer is returned. @var{type} may also\n"
"be a list of types, in which case the size of a @code{struct}\n"
"with ABI-conventional packing is returned.")
#define FUNC_NAME s_scm_sizeof
{
if (SCM_I_INUMP (type))
{
switch (SCM_I_INUM (type))
{
case SCM_FOREIGN_TYPE_FLOAT:
return scm_from_size_t (sizeof (float));
case SCM_FOREIGN_TYPE_DOUBLE:
return scm_from_size_t (sizeof (double));
case SCM_FOREIGN_TYPE_UINT8:
return scm_from_size_t (sizeof (scm_t_uint8));
case SCM_FOREIGN_TYPE_INT8:
return scm_from_size_t (sizeof (scm_t_int8));
case SCM_FOREIGN_TYPE_UINT16:
return scm_from_size_t (sizeof (scm_t_uint16));
case SCM_FOREIGN_TYPE_INT16:
return scm_from_size_t (sizeof (scm_t_int16));
case SCM_FOREIGN_TYPE_UINT32:
return scm_from_size_t (sizeof (scm_t_uint32));
case SCM_FOREIGN_TYPE_INT32:
return scm_from_size_t (sizeof (scm_t_int32));
case SCM_FOREIGN_TYPE_UINT64:
return scm_from_size_t (sizeof (scm_t_uint64));
case SCM_FOREIGN_TYPE_INT64:
return scm_from_size_t (sizeof (scm_t_int64));
default:
scm_wrong_type_arg (FUNC_NAME, 1, type);
}
}
else if (scm_is_eq (type, sym_asterisk))
/* a pointer */
return scm_from_size_t (sizeof (void*));
else if (scm_is_pair (type))
{
/* a struct */
size_t off = 0;
while (scm_is_pair (type))
{
off = ROUND_UP (off, scm_to_size_t (scm_alignof (scm_car (type))));
off += scm_to_size_t (scm_sizeof (scm_car (type)));
type = scm_cdr (type);
}
return scm_from_size_t (off);
}
else
scm_wrong_type_arg (FUNC_NAME, 1, type);
}
#undef FUNC_NAME
/* return 1 on success, 0 on failure */
static int
parse_ffi_type (SCM type, int return_p, long *n_structs, long *n_struct_elts)
{
if (SCM_I_INUMP (type))
{
if ((SCM_I_INUM (type) < 0 )
|| (SCM_I_INUM (type) > SCM_FOREIGN_TYPE_LAST))
return 0;
else if (SCM_I_INUM (type) == SCM_FOREIGN_TYPE_VOID && !return_p)
return 0;
else
return 1;
}
else if (scm_is_eq (type, sym_asterisk))
/* a pointer */
return 1;
else
{
long len;
len = scm_ilength (type);
if (len < 1)
return 0;
while (len--)
{
if (!parse_ffi_type (scm_car (type), 0, n_structs, n_struct_elts))
return 0;
(*n_struct_elts)++;
type = scm_cdr (type);
}
(*n_structs)++;
return 1;
}
}
static void
fill_ffi_type (SCM type, ffi_type *ftype, ffi_type ***type_ptrs,
ffi_type **types)
{
if (SCM_I_INUMP (type))
{
switch (SCM_I_INUM (type))
{
case SCM_FOREIGN_TYPE_FLOAT:
*ftype = ffi_type_float;
return;
case SCM_FOREIGN_TYPE_DOUBLE:
*ftype = ffi_type_double;
return;
case SCM_FOREIGN_TYPE_UINT8:
*ftype = ffi_type_uint8;
return;
case SCM_FOREIGN_TYPE_INT8:
*ftype = ffi_type_sint8;
return;
case SCM_FOREIGN_TYPE_UINT16:
*ftype = ffi_type_uint16;
return;
case SCM_FOREIGN_TYPE_INT16:
*ftype = ffi_type_sint16;
return;
case SCM_FOREIGN_TYPE_UINT32:
*ftype = ffi_type_uint32;
return;
case SCM_FOREIGN_TYPE_INT32:
*ftype = ffi_type_sint32;
return;
case SCM_FOREIGN_TYPE_UINT64:
*ftype = ffi_type_uint64;
return;
case SCM_FOREIGN_TYPE_INT64:
*ftype = ffi_type_sint64;
return;
case SCM_FOREIGN_TYPE_VOID:
*ftype = ffi_type_void;
return;
default:
scm_wrong_type_arg_msg ("make-foreign-function", 0, type,
"foreign type");
}
}
else if (scm_is_eq (type, sym_asterisk))
/* a pointer */
{
*ftype = ffi_type_pointer;
return;
}
else
{
long i, len;
len = scm_ilength (type);
ftype->size = 0;
ftype->alignment = 0;
ftype->type = FFI_TYPE_STRUCT;
ftype->elements = *type_ptrs;
*type_ptrs += len + 1;
for (i = 0; i < len; i++)
{
ftype->elements[i] = *types;
*types += 1;
fill_ffi_type (scm_car (type), ftype->elements[i],
type_ptrs, types);
type = scm_cdr (type);
}
ftype->elements[i] = NULL;
}
}
SCM_DEFINE (scm_make_foreign_function, "make-foreign-function", 3, 0, 0,
(SCM return_type, SCM func_ptr, SCM arg_types),
"Make a foreign function.\n\n"
"Given the foreign void pointer @var{func_ptr}, its argument and\n"
"return types @var{arg_types} and @var{return_type}, return a\n"
"procedure that will pass arguments to the foreign function\n"
"and return appropriate values.\n\n"
"@var{arg_types} should be a list of foreign types.\n"
"@code{return_type} should be a foreign type.")
#define FUNC_NAME s_scm_make_foreign_function
{
SCM walk, scm_cif;
long i, nargs, n_structs, n_struct_elts;
size_t cif_len;
char *mem;
ffi_cif *cif;
ffi_type **type_ptrs;
ffi_type *types;
SCM_VALIDATE_FOREIGN_TYPED (2, func_ptr, VOID);
nargs = scm_ilength (arg_types);
SCM_ASSERT (nargs >= 0, arg_types, 3, FUNC_NAME);
/* fixme: assert nargs < 1<<32 */
n_structs = n_struct_elts = 0;
/* For want of talloc, we're going to have to do this in two passes: first we
figure out how much memory is needed for all types, then we allocate the
cif and the types all in one block. */
if (!parse_ffi_type (return_type, 1, &n_structs, &n_struct_elts))
scm_wrong_type_arg (FUNC_NAME, 1, return_type);
for (walk = arg_types; scm_is_pair (walk); walk = scm_cdr (walk))
if (!parse_ffi_type (scm_car (walk), 0, &n_structs, &n_struct_elts))
scm_wrong_type_arg (FUNC_NAME, 3, scm_car (walk));
/* the memory: with space for the cif itself */
cif_len = sizeof (ffi_cif);
/* then ffi_type pointers: one for each arg, one for each struct
element, and one for each struct (for null-termination) */
cif_len = (ROUND_UP (cif_len, alignof(void*))
+ (nargs + n_structs + n_struct_elts)*sizeof(void*));
/* then the ffi_type structs themselves, one per arg and struct element, and
one for the return val */
cif_len = (ROUND_UP (cif_len, alignof(ffi_type))
+ (nargs + n_struct_elts + 1)*sizeof(ffi_type));
mem = scm_gc_malloc_pointerless (cif_len, "foreign");
scm_cif = scm_take_foreign_pointer (SCM_FOREIGN_TYPE_VOID, mem,
cif_len, NULL);
cif = (ffi_cif *) mem;
/* reuse cif_len to walk through the mem */
cif_len = ROUND_UP (sizeof (ffi_cif), alignof(void*));
type_ptrs = (ffi_type**)(mem + cif_len);
cif_len = ROUND_UP (cif_len
+ (nargs + n_structs + n_struct_elts)*sizeof(void*),
alignof(ffi_type));
types = (ffi_type*)(mem + cif_len);
/* whew. now knit the pointers together. */
cif->rtype = types++;
fill_ffi_type (return_type, cif->rtype, &type_ptrs, &types);
cif->arg_types = type_ptrs;
type_ptrs += nargs;
for (walk = arg_types, i = 0; scm_is_pair (walk); walk = scm_cdr (walk), i++)
{
cif->arg_types[i] = types++;
fill_ffi_type (scm_car (walk), cif->arg_types[i], &type_ptrs, &types);
}
/* round out the cif, and we're done. */
cif->abi = FFI_DEFAULT_ABI;
cif->nargs = nargs;
cif->bytes = 0;
cif->flags = 0;
if (FFI_OK != ffi_prep_cif (cif, FFI_DEFAULT_ABI, cif->nargs, cif->rtype,
cif->arg_types))
scm_misc_error (FUNC_NAME, "ffi_prep_cif failed", SCM_EOL);
return cif_to_procedure (scm_cif, func_ptr);
}
#undef FUNC_NAME
/* Pre-generate trampolines for less than 10 arguments. */
#ifdef WORDS_BIGENDIAN
#define OBJCODE_HEADER 0, 0, 0, 8, 0, 0, 0, 40
#define META_HEADER 0, 0, 0, 32, 0, 0, 0, 0
#else
#define OBJCODE_HEADER 8, 0, 0, 0, 40, 0, 0, 0
#define META_HEADER 32, 0, 0, 0, 0, 0, 0, 0
#endif
#define CODE(nreq) \
OBJCODE_HEADER, \
/* 0 */ scm_op_assert_nargs_ee, 0, nreq, /* assert number of args */ \
/* 3 */ scm_op_object_ref, 0, /* push the pair with the cif and the function pointer */ \
/* 5 */ scm_op_foreign_call, nreq, /* and call (will return value as well) */ \
/* 7 */ scm_op_nop, \
/* 8 */ META (3, 7, nreq)
#define META(start, end, nreq) \
META_HEADER, \
/* 0 */ scm_op_make_eol, /* bindings */ \
/* 1 */ scm_op_make_eol, /* sources */ \
/* 2 */ scm_op_make_int8, start, scm_op_make_int8, end, /* arity: from ip N to ip N */ \
/* 6 */ scm_op_make_int8, nreq, /* the arity is N required args */ \
/* 8 */ scm_op_list, 0, 3, /* make a list of those 3 vals */ \
/* 11 */ scm_op_list, 0, 1, /* and the arities will be a list of that one list */ \
/* 14 */ scm_op_load_symbol, 0, 0, 4, 'n', 'a', 'm', 'e', /* `name' */ \
/* 22 */ scm_op_object_ref, 1, /* the name from the object table */ \
/* 24 */ scm_op_cons, /* make a pair for the properties */ \
/* 25 */ scm_op_list, 0, 4, /* pack bindings, sources, and arities into list */ \
/* 28 */ scm_op_return, /* and return */ \
/* 29 */ scm_op_nop, scm_op_nop, scm_op_nop \
/* 32 */
static const struct
{
scm_t_uint64 dummy; /* ensure 8-byte alignment; perhaps there's a better way */
const scm_t_uint8 bytes[10 * (sizeof (struct scm_objcode) + 8
+ sizeof (struct scm_objcode) + 32)];
} raw_bytecode = {
0,
{
CODE (0), CODE (1), CODE (2), CODE (3), CODE (4),
CODE (5), CODE (6), CODE (7), CODE (8), CODE (9)
}
};
#undef CODE
#undef META
#undef OBJCODE_HEADER
#undef META_HEADER
/*
(defun generate-objcode-cells (n)
"Generate objcode cells for up to N arguments"
(interactive "p")
(let ((i 0))
(while (< i n)
(insert
(format " { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + %d) },\n"
(* (+ 4 4 8 4 4 32) i)))
(insert " { SCM_BOOL_F, SCM_PACK (0) },\n")
(setq i (1+ i)))))
*/
#define STATIC_OBJCODE_TAG \
SCM_PACK (scm_tc7_objcode | (SCM_F_OBJCODE_IS_STATIC << 8))
static const struct
{
scm_t_uint64 dummy; /* alignment */
scm_t_cell cells[10 * 2]; /* 10 double cells */
} objcode_cells = {
0,
/* C-u 1 0 M-x generate-objcode-cells RET */
{
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 0) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 56) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 112) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 168) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 224) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 280) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 336) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 392) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 448) },
{ SCM_BOOL_F, SCM_PACK (0) },
{ STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 504) },
{ SCM_BOOL_F, SCM_PACK (0) }
}
};
static const SCM objcode_trampolines[10] = {
SCM_PACK (objcode_cells.cells+0),
SCM_PACK (objcode_cells.cells+2),
SCM_PACK (objcode_cells.cells+4),
SCM_PACK (objcode_cells.cells+6),
SCM_PACK (objcode_cells.cells+8),
SCM_PACK (objcode_cells.cells+10),
SCM_PACK (objcode_cells.cells+12),
SCM_PACK (objcode_cells.cells+14),
SCM_PACK (objcode_cells.cells+16),
SCM_PACK (objcode_cells.cells+18),
};
static SCM
cif_to_procedure (SCM cif, SCM func_ptr)
{
unsigned nargs = SCM_FOREIGN_POINTER (cif, ffi_cif)->nargs;
SCM objcode, table, ret;
if (nargs < 10)
objcode = objcode_trampolines[nargs];
else
scm_misc_error ("make-foreign-function", "args >= 10 currently unimplemented",
SCM_EOL);
table = scm_c_make_vector (2, SCM_UNDEFINED);
SCM_SIMPLE_VECTOR_SET (table, 0, scm_cons (cif, func_ptr));
SCM_SIMPLE_VECTOR_SET (table, 1, SCM_BOOL_F); /* name */
ret = scm_make_program (objcode, table, SCM_BOOL_F);
return ret;
}
/* Set *LOC to the foreign representation of X with TYPE. */
static void
unpack (const ffi_type *type, void *loc, SCM x)
{
switch (type->type)
{
case FFI_TYPE_FLOAT:
*(float *) loc = scm_to_double (x);
break;
case FFI_TYPE_DOUBLE:
*(double *) loc = scm_to_double (x);
break;
case FFI_TYPE_UINT8:
*(scm_t_uint8 *) loc = scm_to_uint8 (x);
break;
case FFI_TYPE_SINT8:
*(scm_t_int8 *) loc = scm_to_int8 (x);
break;
case FFI_TYPE_UINT16:
*(scm_t_uint16 *) loc = scm_to_uint16 (x);
break;
case FFI_TYPE_SINT16:
*(scm_t_int16 *) loc = scm_to_int16 (x);
break;
case FFI_TYPE_UINT32:
*(scm_t_uint32 *) loc = scm_to_uint32 (x);
break;
case FFI_TYPE_SINT32:
*(scm_t_int32 *) loc = scm_to_int32 (x);
break;
case FFI_TYPE_UINT64:
*(scm_t_uint64 *) loc = scm_to_uint64 (x);
break;
case FFI_TYPE_SINT64:
*(scm_t_int64 *) loc = scm_to_int64 (x);
break;
case FFI_TYPE_STRUCT:
if (!SCM_FOREIGN_TYPED_P (x, VOID))
scm_wrong_type_arg_msg ("foreign-call", 0, x, "foreign void pointer");
if (SCM_FOREIGN_LEN (x) && SCM_FOREIGN_LEN (x) != type->size)
scm_wrong_type_arg_msg ("foreign-call", 0, x,
"foreign void pointer of correct length");
memcpy (loc, SCM_FOREIGN_POINTER (x, void), type->size);
break;
case FFI_TYPE_POINTER:
if (!SCM_FOREIGN_TYPED_P (x, VOID))
scm_wrong_type_arg_msg ("foreign-call", 0, x, "foreign void pointer");
*(void **) loc = SCM_FOREIGN_POINTER (x, void);
break;
default:
abort ();
}
}
/* Return a Scheme representation of the foreign value at LOC of type TYPE. */
static SCM
pack (const ffi_type * type, const void *loc)
{
switch (type->type)
{
case FFI_TYPE_VOID:
return SCM_UNSPECIFIED;
case FFI_TYPE_FLOAT:
return scm_from_double (*(float *) loc);
case FFI_TYPE_DOUBLE:
return scm_from_double (*(double *) loc);
case FFI_TYPE_UINT8:
return scm_from_uint8 (*(scm_t_uint8 *) loc);
case FFI_TYPE_SINT8:
return scm_from_int8 (*(scm_t_int8 *) loc);
case FFI_TYPE_UINT16:
return scm_from_uint16 (*(scm_t_uint16 *) loc);
case FFI_TYPE_SINT16:
return scm_from_int16 (*(scm_t_int16 *) loc);
case FFI_TYPE_UINT32:
return scm_from_uint32 (*(scm_t_uint32 *) loc);
case FFI_TYPE_SINT32:
return scm_from_int32 (*(scm_t_int32 *) loc);
case FFI_TYPE_UINT64:
return scm_from_uint64 (*(scm_t_uint64 *) loc);
case FFI_TYPE_SINT64:
return scm_from_int64 (*(scm_t_int64 *) loc);
case FFI_TYPE_STRUCT:
{
void *mem = scm_gc_malloc_pointerless (type->size, "foreign");
memcpy (mem, loc, type->size);
return scm_take_foreign_pointer (SCM_FOREIGN_TYPE_VOID,
mem, type->size, NULL);
}
case FFI_TYPE_POINTER:
return scm_take_foreign_pointer (SCM_FOREIGN_TYPE_VOID,
*(void **) loc, 0, NULL);
default:
abort ();
}
}
SCM
scm_i_foreign_call (SCM foreign, const SCM *argv)
{
/* FOREIGN is the pair that cif_to_procedure set as the 0th element of the
objtable. */
ffi_cif *cif;
void (*func) (void);
scm_t_uint8 *data;
void *rvalue;
void **args;
unsigned i;
size_t arg_size;
scm_t_ptrdiff off;
cif = SCM_FOREIGN_POINTER (SCM_CAR (foreign), ffi_cif);
func = SCM_FOREIGN_POINTER (SCM_CDR (foreign), void);
/* Argument pointers. */
args = alloca (sizeof (void *) * cif->nargs);
/* Compute the amount of memory needed to store all the argument values.
Note: as of libffi 3.0.9 `cif->bytes' is undocumented and is zero, so it
can't be used for that purpose. */
for (i = 0, arg_size = 0;
i < cif->nargs;
i++, arg_size)
arg_size += ROUND_UP (cif->arg_types[i]->size,
cif->arg_types[i]->alignment);
/* Space for argument values, followed by return value. */
data = alloca (arg_size
+ ROUND_UP (cif->rtype->size, cif->rtype->alignment));
/* Unpack ARGV to native values, setting ARGV pointers. */
for (i = 0, off = 0;
i < cif->nargs;
off += cif->arg_types[i]->size, i++)
{
off = ROUND_UP (off, cif->arg_types[i]->alignment);
args[i] = data + off;
unpack (cif->arg_types[i], args[i], argv[i]);
}
/* Prepare space for the return value. */
off = ROUND_UP (off, cif->rtype->alignment);
rvalue = data + off;
/* off we go! */
ffi_call (cif, func, rvalue, args);
return pack (cif->rtype, rvalue);
}
static void
scm_init_foreign (void)
{
#ifndef SCM_MAGIC_SNARFER
#include "libguile/foreign.x"
#endif
scm_define (sym_void, scm_from_uint8 (SCM_FOREIGN_TYPE_VOID));
scm_define (sym_float, scm_from_uint8 (SCM_FOREIGN_TYPE_FLOAT));
scm_define (sym_double, scm_from_uint8 (SCM_FOREIGN_TYPE_DOUBLE));
scm_define (sym_uint8, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT8));
scm_define (sym_int8, scm_from_uint8 (SCM_FOREIGN_TYPE_INT8));
scm_define (sym_uint16, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT16));
scm_define (sym_int16, scm_from_uint8 (SCM_FOREIGN_TYPE_INT16));
scm_define (sym_uint32, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32));
scm_define (sym_int32, scm_from_uint8 (SCM_FOREIGN_TYPE_INT32));
scm_define (sym_uint64, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64));
scm_define (sym_int64, scm_from_uint8 (SCM_FOREIGN_TYPE_INT64));
scm_define (sym_int,
#if SIZEOF_INT == 8
scm_from_uint8 (SCM_FOREIGN_TYPE_INT64)
#elif SIZEOF_INT == 4
scm_from_uint8 (SCM_FOREIGN_TYPE_INT32)
#else
# error unsupported sizeof (int)
#endif
);
scm_define (sym_unsigned_int,
#if SIZEOF_UNSIGNED_INT == 8
scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)
#elif SIZEOF_UNSIGNED_INT == 4
scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)
#else
# error unsupported sizeof (unsigned int)
#endif
);
scm_define (sym_long,
#if SIZEOF_LONG == 8
scm_from_uint8 (SCM_FOREIGN_TYPE_INT64)
#elif SIZEOF_LONG == 4
scm_from_uint8 (SCM_FOREIGN_TYPE_INT32)
#else
# error unsupported sizeof (long)
#endif
);
scm_define (sym_unsigned_long,
#if SIZEOF_UNSIGNED_LONG == 8
scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)
#elif SIZEOF_UNSIGNED_LONG == 4
scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)
#else
# error unsupported sizeof (unsigned long)
#endif
);
scm_define (sym_size_t,
#if SIZEOF_SIZE_T == 8
scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)
#elif SIZEOF_SIZE_T == 4
scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)
#else
# error unsupported sizeof (size_t)
#endif
);
scm_define (sym_null, PTR2SCM (&null_pointer));
}
void
scm_register_foreign (void)
{
scm_c_register_extension ("libguile-" SCM_EFFECTIVE_VERSION,
"scm_init_foreign",
(scm_t_extension_init_func)scm_init_foreign,
NULL);
foreign_weak_refs = scm_make_weak_key_hash_table (SCM_UNDEFINED);
}
/*
Local Variables:
c-file-style: "gnu"
End:
*/
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