-/* Copyright (C) 2010 Free Software Foundation, Inc.
+/* Copyright (C) 2010, 2011 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
#include <ffi.h>
+#include <alloca.h>
#include <alignof.h>
#include <string.h>
#include <assert.h>
#include "libguile/_scm.h"
#include "libguile/bytevectors.h"
#include "libguile/instructions.h"
+#include "libguile/threads.h"
#include "libguile/foreign.h"
\f
SCM_SYMBOL (sym_int32, "int32");
SCM_SYMBOL (sym_uint64, "uint64");
SCM_SYMBOL (sym_int64, "int64");
+SCM_SYMBOL (sym_short, "short");
SCM_SYMBOL (sym_int, "int");
SCM_SYMBOL (sym_long, "long");
+SCM_SYMBOL (sym_unsigned_short, "unsigned-short");
SCM_SYMBOL (sym_unsigned_int, "unsigned-int");
SCM_SYMBOL (sym_unsigned_long, "unsigned-long");
SCM_SYMBOL (sym_size_t, "size_t");
static SCM pointer_weak_refs = SCM_BOOL_F;
+
static void
register_weak_reference (SCM from, SCM to)
{
- scm_hashq_set_x (pointer_weak_refs, from, to);
+ scm_weak_table_putq_x (pointer_weak_refs, from, to);
}
static void
pointer_finalizer_trampoline (GC_PTR ptr, GC_PTR data)
{
scm_t_pointer_finalizer finalizer = data;
- finalizer (SCM_POINTER_VALUE (PTR2SCM (ptr)));
+ finalizer (SCM_POINTER_VALUE (SCM_PACK_POINTER (ptr)));
+}
+
+SCM_DEFINE (scm_pointer_p, "pointer?", 1, 0, 0,
+ (SCM obj),
+ "Return @code{#t} if @var{obj} is a pointer object, "
+ "@code{#f} otherwise.\n")
+#define FUNC_NAME s_scm_pointer_p
+{
+ return scm_from_bool (SCM_POINTER_P (obj));
}
+#undef FUNC_NAME
SCM_DEFINE (scm_make_pointer, "make-pointer", 1, 1, 0,
(SCM address, SCM finalizer),
{
void *c_finalizer;
scm_t_uintptr c_address;
- SCM result;
c_address = scm_to_uintptr (address);
if (SCM_UNBNDP (finalizer))
c_finalizer = SCM_POINTER_VALUE (finalizer);
}
- if (c_address == 0 && c_finalizer == NULL)
- result = null_pointer;
- else
- result = scm_from_pointer ((void *) c_address, c_finalizer);
-
- return result;
+ return scm_from_pointer ((void *) c_address, c_finalizer);
}
#undef FUNC_NAME
scm_from_pointer (void *ptr, scm_t_pointer_finalizer finalizer)
{
SCM ret;
- scm_t_bits word0;
-
- word0 = scm_tc7_pointer | (finalizer ? (1 << 16UL) : 0UL);
- ret = scm_cell (word0, (scm_t_bits) ptr);
- if (finalizer)
+ if (ptr == NULL && finalizer == NULL)
+ ret = null_pointer;
+ else
{
- /* 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),
- pointer_finalizer_trampoline,
- finalizer,
- &prev_finalizer,
- &prev_finalizer_data);
+ ret = scm_cell (scm_tc7_pointer, (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 (SCM_HEAP_OBJECT_BASE (ret),
+ pointer_finalizer_trampoline,
+ finalizer,
+ &prev_finalizer,
+ &prev_finalizer_data);
+ }
}
return ret;
}
#undef FUNC_NAME
-SCM_DEFINE (scm_dereference_pointer, "dereference-pointer", 1, 0, 0,
+SCM_DEFINE (scm_pointer_to_scm, "pointer->scm", 1, 0, 0,
(SCM pointer),
- "Return the a pointer object representing the pointer "
- "pointed to by @var{pointer}.")
-#define FUNC_NAME s_scm_dereference_pointer
+ "Unsafely cast @var{pointer} to a Scheme object.\n"
+ "Cross your fingers!")
+#define FUNC_NAME s_scm_pointer_to_scm
{
SCM_VALIDATE_POINTER (1, pointer);
+
+ return SCM_PACK ((scm_t_bits) SCM_POINTER_VALUE (pointer));
+}
+#undef FUNC_NAME
- return scm_from_pointer (* (void **) SCM_POINTER_VALUE (pointer), NULL);
+SCM_DEFINE (scm_scm_to_pointer, "scm->pointer", 1, 0, 0,
+ (SCM scm),
+ "Return a foreign pointer object with the @code{object-address}\n"
+ "of @var{scm}.")
+#define FUNC_NAME s_scm_scm_to_pointer
+{
+ SCM ret;
+
+ ret = scm_from_pointer ((void*) SCM_UNPACK (scm), NULL);
+ if (SCM_HEAP_OBJECT_P (ret))
+ register_weak_reference (ret, scm);
+
+ return ret;
}
#undef FUNC_NAME
SCM_DEFINE (scm_pointer_to_bytevector, "pointer->bytevector", 2, 2, 0,
(SCM pointer, SCM len, SCM offset, SCM uvec_type),
- "Return a bytevector aliasing the memory pointed to by\n"
- "@var{pointer}.\n\n"
- "@var{pointer} must be a void pointer, a pointer whose type is\n"
- "@var{void}. By default, the resulting bytevector will alias\n"
- "all of the memory pointed to by @var{pointer}, from beginning\n"
- "to end, treated as a @code{vu8} array.\n\n"
+ "Return a bytevector aliasing the @var{len} bytes pointed\n"
+ "to by @var{pointer}.\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.")
+ "When @var{offset} is passed, it specifies the offset in bytes\n"
+ "relative to @var{pointer} of the memory region aliased by the\n"
+ "returned bytevector.")
#define FUNC_NAME s_scm_pointer_to_bytevector
{
SCM ret;
blen = scm_to_size_t (len);
- ret = scm_c_take_typed_bytevector (ptr + boffset, blen, btype);
- register_weak_reference (ret, pointer);
+ ret = scm_c_take_typed_bytevector (ptr + boffset, blen, btype, pointer);
+
return ret;
}
#undef FUNC_NAME
-SCM_DEFINE (scm_bytevector_to_pointer, "bytevector->pointer", 1, 2, 0,
- (SCM bv, SCM offset, SCM len),
+SCM_DEFINE (scm_bytevector_to_pointer, "bytevector->pointer", 1, 1, 0,
+ (SCM bv, SCM offset),
"Return a pointer pointer aliasing the memory pointed to by\n"
- "@var{bv}.\n\n"
- "The resulting pointer will be a void pointer, a pointer 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 pointer should only alias a\n"
- "subset of the memory, by specifying @var{offset} and @var{len}\n"
- "arguments.")
+ "@var{bv} or @var{offset} bytes after @var{bv} when @var{offset}\n"
+ "is passed.")
#define FUNC_NAME s_scm_bytevector_to_pointer
{
SCM ret;
scm_t_int8 *ptr;
- size_t boffset, blen;
+ size_t boffset;
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_from_pointer (ptr + boffset, NULL);
register_weak_reference (ret, bv);
return ret;
SCM_SET_CELL_WORD_0 (pointer, SCM_CELL_WORD_0 (pointer) | (1 << 16UL));
- GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (pointer),
+ GC_REGISTER_FINALIZER_NO_ORDER (SCM_HEAP_OBJECT_BASE (pointer),
pointer_finalizer_trampoline,
c_finalizer,
&prev_finalizer,
}
#undef FUNC_NAME
-\f
-
void
scm_i_pointer_print (SCM pointer, SCM port, scm_print_state *pstate)
{
- scm_puts ("#<pointer ", port);
- scm_display (scm_pointer_address (pointer), port);
- scm_putc ('>', port);
+ scm_puts_unlocked ("#<pointer 0x", port);
+ scm_uintprint (scm_to_uintptr (scm_pointer_address (pointer)), 16, port);
+ scm_putc_unlocked ('>', port);
+}
+
+\f
+/* Non-primitive helpers functions. These procedures could be
+ implemented in terms of the primitives above but would be inefficient
+ (heap allocation overhead, Scheme/C round trips, etc.) */
+
+SCM_DEFINE (scm_dereference_pointer, "dereference-pointer", 1, 0, 0,
+ (SCM pointer),
+ "Assuming @var{pointer} points to a memory region that\n"
+ "holds a pointer, return this pointer.")
+#define FUNC_NAME s_scm_dereference_pointer
+{
+ SCM_VALIDATE_POINTER (1, pointer);
+
+ return scm_from_pointer (* (void **) SCM_POINTER_VALUE (pointer), NULL);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_string_to_pointer, "string->pointer", 1, 1, 0,
+ (SCM string, SCM encoding),
+ "Return a foreign pointer to a nul-terminated copy of\n"
+ "@var{string} in the given @var{encoding}, defaulting to\n"
+ "the current locale encoding. The C string is freed when\n"
+ "the returned foreign pointer becomes unreachable.\n\n"
+ "This is the Scheme equivalent of @code{scm_to_stringn}.")
+#define FUNC_NAME s_scm_string_to_pointer
+{
+ SCM_VALIDATE_STRING (1, string);
+
+ /* XXX: Finalizers slow down libgc; they could be avoided if
+ `scm_to_string' & co. were able to use libgc-allocated memory. */
+
+ if (SCM_UNBNDP (encoding))
+ return scm_from_pointer (scm_to_locale_string (string), free);
+ else
+ {
+ char *enc;
+ SCM ret;
+
+ SCM_VALIDATE_STRING (2, encoding);
+
+ enc = scm_to_locale_string (encoding);
+ scm_dynwind_begin (0);
+ scm_dynwind_free (enc);
+
+ ret = scm_from_pointer
+ (scm_to_stringn (string, NULL, enc,
+ scm_i_get_conversion_strategy (SCM_BOOL_F)),
+ free);
+
+ scm_dynwind_end ();
+
+ return ret;
+ }
}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_pointer_to_string, "pointer->string", 1, 2, 0,
+ (SCM pointer, SCM length, SCM encoding),
+ "Return the string representing the C string pointed to by\n"
+ "@var{pointer}. If @var{length} is omitted or @code{-1}, the\n"
+ "string is assumed to be nul-terminated. Otherwise\n"
+ "@var{length} is the number of bytes in memory pointed to by\n"
+ "@var{pointer}. The C string is assumed to be in the given\n"
+ "@var{encoding}, defaulting to the current locale encoding.\n\n"
+ "This is the Scheme equivalent of @code{scm_from_stringn}.")
+#define FUNC_NAME s_scm_pointer_to_string
+{
+ size_t len;
+
+ SCM_VALIDATE_POINTER (1, pointer);
+
+ if (SCM_UNBNDP (length)
+ || scm_is_true (scm_eqv_p (length, scm_from_int (-1))))
+ len = (size_t)-1;
+ else
+ len = scm_to_size_t (length);
+
+ if (SCM_UNBNDP (encoding))
+ return scm_from_locale_stringn (SCM_POINTER_VALUE (pointer), len);
+ else
+ {
+ char *enc;
+ SCM ret;
+
+ SCM_VALIDATE_STRING (3, encoding);
+
+ enc = scm_to_locale_string (encoding);
+ scm_dynwind_begin (0);
+ scm_dynwind_free (enc);
+
+ ret = scm_from_stringn (SCM_POINTER_VALUE (pointer), len, enc,
+ scm_i_get_conversion_strategy (SCM_BOOL_F));
+
+ scm_dynwind_end ();
+
+ return ret;
+ }
+}
+#undef FUNC_NAME
\f
switch (SCM_I_INUM (type))
{
case SCM_FOREIGN_TYPE_FLOAT:
- return scm_from_size_t (alignof (float));
+ return scm_from_size_t (alignof_type (float));
case SCM_FOREIGN_TYPE_DOUBLE:
- return scm_from_size_t (alignof (double));
+ return scm_from_size_t (alignof_type (double));
case SCM_FOREIGN_TYPE_UINT8:
- return scm_from_size_t (alignof (scm_t_uint8));
+ return scm_from_size_t (alignof_type (scm_t_uint8));
case SCM_FOREIGN_TYPE_INT8:
- return scm_from_size_t (alignof (scm_t_int8));
+ return scm_from_size_t (alignof_type (scm_t_int8));
case SCM_FOREIGN_TYPE_UINT16:
- return scm_from_size_t (alignof (scm_t_uint16));
+ return scm_from_size_t (alignof_type (scm_t_uint16));
case SCM_FOREIGN_TYPE_INT16:
- return scm_from_size_t (alignof (scm_t_int16));
+ return scm_from_size_t (alignof_type (scm_t_int16));
case SCM_FOREIGN_TYPE_UINT32:
- return scm_from_size_t (alignof (scm_t_uint32));
+ return scm_from_size_t (alignof_type (scm_t_uint32));
case SCM_FOREIGN_TYPE_INT32:
- return scm_from_size_t (alignof (scm_t_int32));
+ return scm_from_size_t (alignof_type (scm_t_int32));
case SCM_FOREIGN_TYPE_UINT64:
- return scm_from_size_t (alignof (scm_t_uint64));
+ return scm_from_size_t (alignof_type (scm_t_uint64));
case SCM_FOREIGN_TYPE_INT64:
- return scm_from_size_t (alignof (scm_t_int64));
+ return scm_from_size_t (alignof_type (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*));
+ return scm_from_size_t (alignof_type (void*));
else if (scm_is_pair (type))
- /* a struct, yo */
- return scm_alignof (scm_car (type));
+ {
+ /* TYPE is a structure. Section 3-3 of the i386, x86_64, PowerPC,
+ and SPARC P.S. of the System V ABI all say: "Aggregates
+ (structures and arrays) and unions assume the alignment of
+ their most strictly aligned component." */
+ size_t max;
+
+ for (max = 0; scm_is_pair (type); type = SCM_CDR (type))
+ {
+ size_t align;
+
+ align = scm_to_size_t (scm_alignof (SCM_CAR (type)));
+ if (align > max)
+ max = align;
+ }
+
+ return scm_from_size_t (max);
+ }
else
scm_wrong_type_arg (FUNC_NAME, 1, type);
}
*ftype = ffi_type_void;
return;
default:
- scm_wrong_type_arg_msg ("make-foreign-function", 0, type,
+ scm_wrong_type_arg_msg ("pointer->procedure", 0, type,
"foreign 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
+
+/* Return a "cif" (call interface) for the given RETURN_TYPE and
+ ARG_TYPES. */
+static ffi_cif *
+make_cif (SCM return_type, SCM arg_types, const char *caller)
+#define FUNC_NAME caller
{
- SCM walk, scm_cif;
+ SCM walk;
long i, nargs, n_structs, n_struct_elts;
size_t cif_len;
char *mem;
ffi_type **type_ptrs;
ffi_type *types;
- SCM_VALIDATE_POINTER (2, func_ptr);
-
nargs = scm_ilength (arg_types);
SCM_ASSERT (nargs >= 0, arg_types, 3, FUNC_NAME);
/* fixme: assert nargs < 1<<32 */
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*));
-
+ cif_len = (ROUND_UP (cif_len, alignof_type (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));
+ cif_len = (ROUND_UP (cif_len, alignof_type (ffi_type))
+ + (nargs + n_struct_elts + 1)*sizeof(ffi_type));
mem = scm_gc_malloc_pointerless (cif_len, "foreign");
- scm_cif = scm_from_pointer (mem, NULL);
+ /* ensure all the memory is initialized, even the holes */
+ memset (mem, 0, cif_len);
cif = (ffi_cif *) mem;
/* reuse cif_len to walk through the mem */
- cif_len = ROUND_UP (sizeof (ffi_cif), alignof(void*));
+ cif_len = ROUND_UP (sizeof (ffi_cif), alignof_type (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));
+ + (nargs + n_structs + n_struct_elts)*sizeof(void*),
+ alignof_type (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->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);
+ cif->arg_types))
+ SCM_MISC_ERROR ("ffi_prep_cif failed", SCM_EOL);
- return cif_to_procedure (scm_cif, func_ptr);
+ return cif;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_pointer_to_procedure, "pointer->procedure", 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_pointer_to_procedure
+{
+ ffi_cif *cif;
+
+ SCM_VALIDATE_POINTER (2, func_ptr);
+
+ cif = make_cif (return_type, arg_types, FUNC_NAME);
+
+ return cif_to_procedure (scm_from_pointer (cif, NULL), func_ptr);
}
#undef FUNC_NAME
(setq i (1+ i)))))
*/
#define STATIC_OBJCODE_TAG \
- SCM_PACK (scm_tc7_objcode | (SCM_F_OBJCODE_IS_STATIC << 8))
+ SCM_PACK (SCM_MAKE_OBJCODE_TAG (SCM_OBJCODE_TYPE_STATIC, 0))
static const struct
{
/* Set *LOC to the foreign representation of X with TYPE. */
static void
-unpack (const ffi_type *type, void *loc, SCM x)
+unpack (const ffi_type *type, void *loc, SCM x, int return_value_p)
+#define FUNC_NAME "scm_i_foreign_call"
{
switch (type->type)
{
case FFI_TYPE_DOUBLE:
*(double *) loc = scm_to_double (x);
break;
+
+ /* For integer return values smaller than `int', libffi expects the
+ result in an `ffi_arg'-long buffer. */
+
case FFI_TYPE_UINT8:
- *(scm_t_uint8 *) loc = scm_to_uint8 (x);
+ if (return_value_p)
+ *(ffi_arg *) loc = scm_to_uint8 (x);
+ else
+ *(scm_t_uint8 *) loc = scm_to_uint8 (x);
break;
case FFI_TYPE_SINT8:
- *(scm_t_int8 *) loc = scm_to_int8 (x);
+ if (return_value_p)
+ *(ffi_arg *) loc = scm_to_int8 (x);
+ else
+ *(scm_t_int8 *) loc = scm_to_int8 (x);
break;
case FFI_TYPE_UINT16:
- *(scm_t_uint16 *) loc = scm_to_uint16 (x);
+ if (return_value_p)
+ *(ffi_arg *) loc = scm_to_uint16 (x);
+ else
+ *(scm_t_uint16 *) loc = scm_to_uint16 (x);
break;
case FFI_TYPE_SINT16:
- *(scm_t_int16 *) loc = scm_to_int16 (x);
+ if (return_value_p)
+ *(ffi_arg *) loc = scm_to_int16 (x);
+ else
+ *(scm_t_int16 *) loc = scm_to_int16 (x);
break;
case FFI_TYPE_UINT32:
- *(scm_t_uint32 *) loc = scm_to_uint32 (x);
+ if (return_value_p)
+ *(ffi_arg *) loc = scm_to_uint32 (x);
+ else
+ *(scm_t_uint32 *) loc = scm_to_uint32 (x);
break;
case FFI_TYPE_SINT32:
- *(scm_t_int32 *) loc = scm_to_int32 (x);
+ if (return_value_p)
+ *(ffi_arg *) loc = scm_to_int32 (x);
+ else
+ *(scm_t_int32 *) loc = scm_to_int32 (x);
break;
case FFI_TYPE_UINT64:
*(scm_t_uint64 *) loc = scm_to_uint64 (x);
*(scm_t_int64 *) loc = scm_to_int64 (x);
break;
case FFI_TYPE_STRUCT:
+ SCM_VALIDATE_POINTER (1, x);
memcpy (loc, SCM_POINTER_VALUE (x), type->size);
break;
case FFI_TYPE_POINTER:
+ SCM_VALIDATE_POINTER (1, x);
*(void **) loc = SCM_POINTER_VALUE (x);
break;
+ case FFI_TYPE_VOID:
+ /* Do nothing. */
+ break;
default:
abort ();
}
}
+#undef FUNC_NAME
-/* Return a Scheme representation of the foreign value at LOC of type TYPE. */
+/* Return a Scheme representation of the foreign value at LOC of type
+ TYPE. When RETURN_VALUE_P is true, LOC is assumed to point to a
+ return value buffer; otherwise LOC is assumed to point to an
+ argument buffer. */
static SCM
-pack (const ffi_type * type, const void *loc)
+pack (const ffi_type * type, const void *loc, int return_value_p)
{
switch (type->type)
{
return scm_from_double (*(float *) loc);
case FFI_TYPE_DOUBLE:
return scm_from_double (*(double *) loc);
+
+ /* For integer return values smaller than `int', libffi stores the
+ result in an `ffi_arg'-long buffer, of which only the
+ significant bits must be kept---hence the pair of casts below.
+ See <http://thread.gmane.org/gmane.comp.lib.ffi.general/406>
+ for details. */
+
case FFI_TYPE_UINT8:
- return scm_from_uint8 (*(scm_t_uint8 *) loc);
+ if (return_value_p)
+ return scm_from_uint8 ((scm_t_uint8) *(ffi_arg *) loc);
+ else
+ return scm_from_uint8 (* (scm_t_uint8 *) loc);
case FFI_TYPE_SINT8:
- return scm_from_int8 (*(scm_t_int8 *) loc);
+ if (return_value_p)
+ return scm_from_int8 ((scm_t_int8) *(ffi_arg *) loc);
+ else
+ return scm_from_int8 (* (scm_t_int8 *) loc);
case FFI_TYPE_UINT16:
- return scm_from_uint16 (*(scm_t_uint16 *) loc);
+ if (return_value_p)
+ return scm_from_uint16 ((scm_t_uint16) *(ffi_arg *) loc);
+ else
+ return scm_from_uint16 (* (scm_t_uint16 *) loc);
case FFI_TYPE_SINT16:
- return scm_from_int16 (*(scm_t_int16 *) loc);
+ if (return_value_p)
+ return scm_from_int16 ((scm_t_int16) *(ffi_arg *) loc);
+ else
+ return scm_from_int16 (* (scm_t_int16 *) loc);
case FFI_TYPE_UINT32:
- return scm_from_uint32 (*(scm_t_uint32 *) loc);
+ if (return_value_p)
+ return scm_from_uint32 ((scm_t_uint32) *(ffi_arg *) loc);
+ else
+ return scm_from_uint32 (* (scm_t_uint32 *) loc);
case FFI_TYPE_SINT32:
- return scm_from_int32 (*(scm_t_int32 *) loc);
+ if (return_value_p)
+ return scm_from_int32 ((scm_t_int32) *(ffi_arg *) loc);
+ else
+ 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");
args[i] = (void *) ROUND_UP ((scm_t_uintptr) data + off,
cif->arg_types[i]->alignment);
assert ((scm_t_uintptr) args[i] % cif->arg_types[i]->alignment == 0);
- unpack (cif->arg_types[i], args[i], argv[i]);
+ unpack (cif->arg_types[i], args[i], argv[i], 0);
}
/* Prepare space for the return value. On some platforms, such as
/* off we go! */
ffi_call (cif, func, rvalue, args);
- return pack (cif->rtype, rvalue);
+ return pack (cif->rtype, rvalue, 1);
}
\f
+/* Function pointers aka. "callbacks" or "closures". */
+
+#ifdef FFI_CLOSURES
+
+/* Trampoline to invoke a libffi closure that wraps a Scheme
+ procedure. */
+static void
+invoke_closure (ffi_cif *cif, void *ret, void **args, void *data)
+{
+ size_t i;
+ SCM proc, *argv, result;
+
+ proc = SCM_PACK_POINTER (data);
+
+ argv = alloca (cif->nargs * sizeof (*argv));
+
+ /* Pack ARGS to SCM values, setting ARGV pointers. */
+ for (i = 0; i < cif->nargs; i++)
+ argv[i] = pack (cif->arg_types[i], args[i], 0);
+
+ result = scm_call_n (proc, argv, cif->nargs);
+
+ unpack (cif->rtype, ret, result, 1);
+}
+
+SCM_DEFINE (scm_procedure_to_pointer, "procedure->pointer", 3, 0, 0,
+ (SCM return_type, SCM proc, SCM arg_types),
+ "Return a pointer to a C function of type @var{return-type}\n"
+ "taking arguments of types @var{arg-types} (a list) and\n"
+ "behaving as a proxy to procedure @var{proc}. Thus\n"
+ "@var{proc}'s arity, supported argument types, and return\n"
+ "type should match @var{return-type} and @var{arg-types}.\n")
+#define FUNC_NAME s_scm_procedure_to_pointer
+{
+ SCM cif_pointer, pointer;
+ ffi_cif *cif;
+ ffi_status err;
+ void *closure, *executable;
+
+ cif = make_cif (return_type, arg_types, FUNC_NAME);
+
+ closure = ffi_closure_alloc (sizeof (ffi_closure), &executable);
+ err = ffi_prep_closure_loc ((ffi_closure *) closure, cif,
+ invoke_closure, SCM_UNPACK_POINTER (proc),
+ executable);
+ if (err != FFI_OK)
+ {
+ ffi_closure_free (closure);
+ SCM_MISC_ERROR ("`ffi_prep_closure_loc' failed", SCM_EOL);
+ }
+
+ /* CIF points to GC-managed memory and it should remain as long as
+ POINTER (see below) is live. Wrap it in a Scheme pointer to then
+ hold a weak reference on it. */
+ cif_pointer = scm_from_pointer (cif, NULL);
+
+ if (closure == executable)
+ {
+ pointer = scm_from_pointer (executable, ffi_closure_free);
+ register_weak_reference (pointer,
+ scm_list_2 (proc, cif_pointer));
+ }
+ else
+ {
+ /* CLOSURE needs to be freed eventually. However, since
+ `GC_all_interior_pointers' is disabled, we can't just register
+ a finalizer for CLOSURE. Instead, we create a pointer object
+ for CLOSURE, with a finalizer, and register it as a weak
+ reference of POINTER. */
+ SCM friend;
+
+ pointer = scm_from_pointer (executable, NULL);
+ friend = scm_from_pointer (closure, ffi_closure_free);
+
+ register_weak_reference (pointer,
+ scm_list_3 (proc, cif_pointer, friend));
+ }
+
+ return pointer;
+}
+#undef FUNC_NAME
+
+#endif /* FFI_CLOSURES */
+
+\f
static void
scm_init_foreign (void)
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_short,
+#if SIZEOF_SHORT == 8
+ scm_from_uint8 (SCM_FOREIGN_TYPE_INT64)
+#elif SIZEOF_SHORT == 4
+ scm_from_uint8 (SCM_FOREIGN_TYPE_INT32)
+#elif SIZEOF_SHORT == 2
+ scm_from_uint8 (SCM_FOREIGN_TYPE_INT16)
+#else
+# error unsupported sizeof (short)
+#endif
+ );
+
+ scm_define (sym_unsigned_short,
+#if SIZEOF_SHORT == 8
+ scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)
+#elif SIZEOF_SHORT == 4
+ scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)
+#elif SIZEOF_SHORT == 2
+ scm_from_uint8 (SCM_FOREIGN_TYPE_UINT16)
+#else
+# error unsupported sizeof (short)
+#endif
+ );
+
scm_define (sym_int,
#if SIZEOF_INT == 8
scm_from_uint8 (SCM_FOREIGN_TYPE_INT64)
"scm_init_foreign",
(scm_t_extension_init_func)scm_init_foreign,
NULL);
- pointer_weak_refs = scm_make_weak_key_hash_table (SCM_UNDEFINED);
+ pointer_weak_refs = scm_c_make_weak_table (0, SCM_WEAK_TABLE_KIND_KEY);
}
/*
HCoop / bpt / guile.git / blobdiff