glib/girffi.c

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/* GObject introspection: Helper functions for ffi integration
*
* Copyright (C) 2008 Red Hat, Inc
* Copyright (C) 2005 Matthias Clasen
*
* 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 2 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <config.h>
#include <errno.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>
#include "girffi.h"
#include "girepository.h"
ffi_type *
g_ir_ffi_get_ffi_type (GITypeTag tag)
{
switch (tag)
{
case GI_TYPE_TAG_VOID:
return &ffi_type_void;
case GI_TYPE_TAG_BOOLEAN:
return &ffi_type_uint;
case GI_TYPE_TAG_INT8:
return &ffi_type_sint8;
case GI_TYPE_TAG_UINT8:
return &ffi_type_uint8;
case GI_TYPE_TAG_INT16:
return &ffi_type_sint16;
case GI_TYPE_TAG_UINT16:
return &ffi_type_uint16;
case GI_TYPE_TAG_INT32:
return &ffi_type_sint32;
case GI_TYPE_TAG_UINT32:
return &ffi_type_uint32;
case GI_TYPE_TAG_INT64:
return &ffi_type_sint64;
case GI_TYPE_TAG_UINT64:
return &ffi_type_uint64;
case GI_TYPE_TAG_SHORT:
return &ffi_type_sshort;
case GI_TYPE_TAG_USHORT:
return &ffi_type_ushort;
case GI_TYPE_TAG_INT:
return &ffi_type_sint;
case GI_TYPE_TAG_UINT:
return &ffi_type_uint;
case GI_TYPE_TAG_SSIZE:
#if GLIB_SIZEOF_SIZE_T == 4
return &ffi_type_sint32;
#elif GLIB_SIZEOF_SIZE_T == 8
return &ffi_type_sint64;
#else
# error "Unexpected size for size_t: not 4 or 8"
#endif
case GI_TYPE_TAG_LONG:
return &ffi_type_slong;
case GI_TYPE_TAG_SIZE:
case GI_TYPE_TAG_GTYPE:
#if GLIB_SIZEOF_SIZE_T == 4
return &ffi_type_uint32;
#elif GLIB_SIZEOF_SIZE_T == 8
return &ffi_type_uint64;
#else
# error "Unexpected size for size_t: not 4 or 8"
#endif
case GI_TYPE_TAG_TIME_T:
#if SIZEOF_TIME_T == 4
return &ffi_type_sint32;
#elif SIZEOF_TIME_T == 8
return &ffi_type_sint64;
#else
# error "Unexpected size for time_t: not 4 or 8"
#endif
case GI_TYPE_TAG_ULONG:
return &ffi_type_ulong;
case GI_TYPE_TAG_FLOAT:
return &ffi_type_float;
case GI_TYPE_TAG_DOUBLE:
return &ffi_type_double;
case GI_TYPE_TAG_UTF8:
case GI_TYPE_TAG_FILENAME:
case GI_TYPE_TAG_ARRAY:
case GI_TYPE_TAG_INTERFACE:
case GI_TYPE_TAG_GLIST:
case GI_TYPE_TAG_GSLIST:
case GI_TYPE_TAG_GHASH:
case GI_TYPE_TAG_ERROR:
return &ffi_type_pointer;
}
g_assert_not_reached ();
return NULL;
}
/**
* g_callable_info_get_ffi_arg_types:
* @callable_info: a callable info from a typelib
*
* Return value: an array of ffi_type*. The array itself
* should be freed using g_free() after use.
*/
ffi_type **
g_callable_info_get_ffi_arg_types (GICallableInfo *callable_info)
{
ffi_type **arg_types;
gint n_args, i;
g_return_val_if_fail (callable_info != NULL, NULL);
n_args = g_callable_info_get_n_args (callable_info);
arg_types = (ffi_type **) g_new0 (ffi_type *, n_args + 1);
for (i = 0; i < n_args; ++i)
{
GIArgInfo *arg_info = g_callable_info_get_arg (callable_info, i);
GITypeInfo *arg_type = g_arg_info_get_type (arg_info);
GITypeTag type_tag = g_type_info_get_tag (arg_type);
arg_types[i] = g_ir_ffi_get_ffi_type (type_tag);
g_base_info_unref ((GIBaseInfo *)arg_info);
g_base_info_unref ((GIBaseInfo *)arg_type);
}
arg_types[n_args] = NULL;
return arg_types;
}
/**
* g_callable_info_get_ffi_return_type:
* @callable_info: a callable info from a typelib
*
* Fetches the ffi_type for a corresponding return value of
* a #GICallableInfo
* Return value: the ffi_type for the return value
*/
ffi_type *
g_callable_info_get_ffi_return_type (GICallableInfo *callable_info)
{
GITypeInfo *return_type;
GITypeTag type_tag;
g_return_val_if_fail (callable_info != NULL, NULL);
return_type = g_callable_info_get_return_type (callable_info);
type_tag = g_type_info_get_tag (return_type);
return g_ir_ffi_get_ffi_type (type_tag);
}
/**
* g_callable_info_prepare_closure:
* @callable_info: a callable info from a typelib
* @cif: a ffi_cif structure
* @callback: the ffi callback
* @user_data: data to be passed into the callback
*
* Prepares a callback for ffi invocation.
*
* Note: this function requires the heap to be executable, which
* might not function properly on systems with SELinux enabled.
*
* Return value: the ffi_closure or NULL on error.
* The return value should be freed by calling g_callable_info_prepare_closure().
*/
ffi_closure *
g_callable_info_prepare_closure (GICallableInfo *callable_info,
ffi_cif *cif,
GIFFIClosureCallback callback,
gpointer user_data)
{
ffi_closure *closure;
ffi_status status;
g_return_val_if_fail (callable_info != NULL, FALSE);
g_return_val_if_fail (cif != NULL, FALSE);
g_return_val_if_fail (callback != NULL, FALSE);
closure = mmap (NULL, sizeof (ffi_closure),
PROT_EXEC | PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, -1, sysconf (_SC_PAGE_SIZE));
if (!closure)
{
g_warning("mmap failed: %s\n", strerror(errno));
return NULL;
}
status = ffi_prep_cif (cif, FFI_DEFAULT_ABI,
g_callable_info_get_n_args (callable_info),
g_callable_info_get_ffi_return_type (callable_info),
g_callable_info_get_ffi_arg_types (callable_info));
if (status != FFI_OK)
{
g_warning("ffi_prep_cif failed: %d\n", status);
munmap(closure, sizeof (closure));
return NULL;
}
status = ffi_prep_closure (closure, cif, callback, user_data);
if (status != FFI_OK)
{
g_warning ("ffi_prep_closure failed: %d\n", status);
munmap(closure, sizeof (closure));
return NULL;
}
if (mprotect(closure, sizeof (closure), PROT_READ | PROT_EXEC) == -1)
{
g_warning ("ffi_prep_closure failed: %s\n", strerror(errno));
munmap(closure, sizeof (closure));
return NULL;
}
return closure;
}
/**
2009-02-12 04:32:25 +01:00
* g_callable_info_free_closure:
* @callable_info: a callable info from a typelib
* @closure: ffi closure
*
* Frees a ffi_closure returned from g_callable_info_prepare_closure()
*/
void
g_callable_info_free_closure (GICallableInfo *callable_info,
ffi_closure *closure)
{
munmap(closure, sizeof (closure));
}