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844544f72c
glib/girepository/girffi.c
Philip Withnall 844544f72c girepository: Add SPDX license header to all obvious files 
Add the SPDX license runes to all the files which have an obvious
copyright header already. This is a mechanical edit.

Signed-off-by: Philip Withnall <philip@tecnocode.co.uk>

Helps: #3155
2023-10-25 17:10:10 +01:00

505 lines
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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
* GObject introspection: Helper functions for ffi integration
*
* Copyright (C) 2008 Red Hat, Inc
* Copyright (C) 2005 Matthias Clasen
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* 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 <sys/types.h>
#include <errno.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "girffi.h"
#include "girepository.h"
#include "girepository-private.h"
/**
* SECTION:girffi
* @short_description: TODO
* @title: girffi
*
* TODO
*/
static ffi_type *
gi_type_tag_get_ffi_type_internal (GITypeTag tag,
gboolean is_pointer,
gboolean is_enum)
{
switch (tag)
{
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:
case GI_TYPE_TAG_UNICHAR:
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_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_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_GLIST:
case GI_TYPE_TAG_GSLIST:
case GI_TYPE_TAG_GHASH:
case GI_TYPE_TAG_ERROR:
return &ffi_type_pointer;
case GI_TYPE_TAG_INTERFACE:
{
/* We need to handle enums specially:
* https://bugzilla.gnome.org/show_bug.cgi?id=665150
*/
if (!is_enum)
return &ffi_type_pointer;
else
return &ffi_type_sint32;
}
case GI_TYPE_TAG_VOID:
if (is_pointer)
return &ffi_type_pointer;
else
return &ffi_type_void;
default:
break;
}
g_assert_not_reached ();
return NULL;
}
/**
* gi_type_tag_get_ffi_type:
* @type_tag: A #GITypeTag
* @is_pointer: Whether or not this is a pointer type
*
* TODO
*
* Returns: A #ffi_type corresponding to the platform default C ABI for @tag and @is_pointer.
*/
ffi_type *
gi_type_tag_get_ffi_type (GITypeTag type_tag,
gboolean is_pointer)
{
return gi_type_tag_get_ffi_type_internal (type_tag, is_pointer, FALSE);
}
/**
* g_type_info_get_ffi_type:
* @info: A #GITypeInfo
*
* TODO
*
* Returns: A #ffi_type corresponding to the platform default C ABI for @info.
*/
ffi_type *
g_type_info_get_ffi_type (GITypeInfo *info)
{
gboolean is_enum = FALSE;
GIBaseInfo *iinfo;
if (g_type_info_get_tag (info) == GI_TYPE_TAG_INTERFACE)
{
iinfo = g_type_info_get_interface (info);
switch (g_base_info_get_type (iinfo))
{
case GI_INFO_TYPE_ENUM:
case GI_INFO_TYPE_FLAGS:
is_enum = TRUE;
break;
default:
break;
}
g_base_info_unref (iinfo);
}
return gi_type_tag_get_ffi_type_internal (g_type_info_get_tag (info), g_type_info_is_pointer (info), is_enum);
}
/**
* g_callable_info_get_ffi_arg_types:
* @callable_info: a callable info from a typelib
* @n_args_p: (out): The number of arguments
*
* TODO
*
* Returns: an array of ffi_type*. The array itself
* should be freed using g_free() after use.
*/
static ffi_type **
g_callable_info_get_ffi_arg_types (GICallableInfo *callable_info,
int *n_args_p)
{
ffi_type **arg_types;
gboolean is_method, throws;
gint n_args, n_invoke_args, i, offset;
g_return_val_if_fail (callable_info != NULL, NULL);
n_args = g_callable_info_get_n_args (callable_info);
is_method = g_callable_info_is_method (callable_info);
throws = g_callable_info_can_throw_gerror (callable_info);
offset = is_method ? 1 : 0;
n_invoke_args = n_args;
if (is_method)
n_invoke_args++;
if (throws)
n_invoke_args++;
if (n_args_p)
*n_args_p = n_invoke_args;
arg_types = (ffi_type **) g_new0 (ffi_type *, n_invoke_args + 1);
if (is_method)
arg_types[0] = &ffi_type_pointer;
if (throws)
arg_types[n_invoke_args - 1] = &ffi_type_pointer;
for (i = 0; i < n_args; ++i)
{
GIArgInfo arg_info;
GITypeInfo arg_type;
g_callable_info_load_arg (callable_info, i, &arg_info);
g_arg_info_load_type (&arg_info, &arg_type);
switch (g_arg_info_get_direction (&arg_info))
{
case GI_DIRECTION_IN:
arg_types[i + offset] = g_type_info_get_ffi_type (&arg_type);
break;
case GI_DIRECTION_OUT:
case GI_DIRECTION_INOUT:
arg_types[i + offset] = &ffi_type_pointer;
break;
default:
g_assert_not_reached ();
}
}
arg_types[n_invoke_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
*
* Returns: the ffi_type for the return value
*/
static ffi_type *
g_callable_info_get_ffi_return_type (GICallableInfo *callable_info)
{
GITypeInfo *return_type;
ffi_type *return_ffi_type;
g_return_val_if_fail (callable_info != NULL, NULL);
return_type = g_callable_info_get_return_type (callable_info);
return_ffi_type = g_type_info_get_ffi_type (return_type);
g_base_info_unref((GIBaseInfo*)return_type);
return return_ffi_type;
}
/**
* g_function_info_prep_invoker:
* @info: A #GIFunctionInfo
* @invoker: Output invoker structure
* @error: A #GError
*
* Initialize the caller-allocated @invoker structure with a cache
* of information needed to invoke the C function corresponding to
* @info with the platform's default ABI.
*
* A primary intent of this function is that a dynamic structure allocated
* by a language binding could contain a #GIFunctionInvoker structure
* inside the binding's function mapping.
*
* Returns: %TRUE on success, %FALSE otherwise with @error set.
*/
gboolean
g_function_info_prep_invoker (GIFunctionInfo *info,
GIFunctionInvoker *invoker,
GError **error)
{
const char *symbol;
gpointer addr;
g_return_val_if_fail (info != NULL, FALSE);
g_return_val_if_fail (invoker != NULL, FALSE);
symbol = g_function_info_get_symbol ((GIFunctionInfo*) info);
if (!g_typelib_symbol (g_base_info_get_typelib((GIBaseInfo *) info),
symbol, &addr))
{
g_set_error (error,
G_INVOKE_ERROR,
G_INVOKE_ERROR_SYMBOL_NOT_FOUND,
"Could not locate %s: %s", symbol, g_module_error ());
return FALSE;
}
return g_function_invoker_new_for_address (addr, info, invoker, error);
}
/**
* g_function_invoker_new_for_address:
* @addr: The address
* @info: A #GICallableInfo
* @invoker: Output invoker structure
* @error: A #GError
*
* Initialize the caller-allocated @invoker structure with a cache
* of information needed to invoke the C function corresponding to
* @info with the platform's default ABI.
*
* A primary intent of this function is that a dynamic structure allocated
* by a language binding could contain a #GIFunctionInvoker structure
* inside the binding's function mapping.
*
* Returns: %TRUE on success, %FALSE otherwise with @error set.
*/
gboolean
g_function_invoker_new_for_address (gpointer addr,
GICallableInfo *info,
GIFunctionInvoker *invoker,
GError **error)
{
ffi_type **atypes;
gint n_args;
g_return_val_if_fail (info != NULL, FALSE);
g_return_val_if_fail (invoker != NULL, FALSE);
invoker->native_address = addr;
atypes = g_callable_info_get_ffi_arg_types (info, &n_args);
return ffi_prep_cif (&(invoker->cif), FFI_DEFAULT_ABI, n_args,
g_callable_info_get_ffi_return_type (info),
atypes) == FFI_OK;
}
/**
* g_function_invoker_destroy:
* @invoker: A #GIFunctionInvoker
*
* Release all resources allocated for the internals of @invoker; callers
* are responsible for freeing any resources allocated for the structure
* itself however.
*/
void
g_function_invoker_destroy (GIFunctionInvoker *invoker)
{
g_free (invoker->cif.arg_types);
}
typedef struct {
ffi_closure ffi_closure;
gpointer writable_self;
gpointer native_address;
} GIClosureWrapper;
/**
* g_callable_info_create_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.
*
* Returns: the ffi_closure or NULL on error. The return value
* should be freed by calling g_callable_info_destroy_closure().
*/
ffi_closure *
g_callable_info_create_closure (GICallableInfo *callable_info,
ffi_cif *cif,
GIFFIClosureCallback callback,
gpointer user_data)
{
gpointer exec_ptr;
int n_args;
ffi_type **atypes;
GIClosureWrapper *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 = ffi_closure_alloc (sizeof (GIClosureWrapper), &exec_ptr);
if (!closure)
{
g_warning ("could not allocate closure\n");
return NULL;
}
closure->writable_self = closure;
closure->native_address = exec_ptr;
atypes = g_callable_info_get_ffi_arg_types (callable_info, &n_args);
status = ffi_prep_cif (cif, FFI_DEFAULT_ABI, n_args,
g_callable_info_get_ffi_return_type (callable_info),
atypes);
if (status != FFI_OK)
{
g_warning ("ffi_prep_cif failed: %d\n", status);
ffi_closure_free (closure);
return NULL;
}
status = ffi_prep_closure_loc (&closure->ffi_closure, cif, callback, user_data, exec_ptr);
if (status != FFI_OK)
{
g_warning ("ffi_prep_closure failed: %d\n", status);
ffi_closure_free (closure);
return NULL;
}
return &closure->ffi_closure;
}
/**
* g_callable_info_get_closure_native_address:
* @callable_info: a callable info from a typelib
* @closure: ffi closure
*
* Gets callable code from ffi_closure prepared by g_callable_info_create_closure()
*/
gpointer *
g_callable_info_get_closure_native_address (GICallableInfo *callable_info,
ffi_closure *closure)
{
GIClosureWrapper *wrapper = (GIClosureWrapper *)closure;
return wrapper->native_address;
}
/**
* g_callable_info_destroy_closure:
* @callable_info: a callable info from a typelib
* @closure: ffi closure
*
* Frees a ffi_closure returned from g_callable_info_create_closure()
*/
void
g_callable_info_destroy_closure (GICallableInfo *callable_info,
ffi_closure *closure)
{
GIClosureWrapper *wrapper = (GIClosureWrapper *)closure;
g_free (wrapper->ffi_closure.cif->arg_types);
ffi_closure_free (wrapper->writable_self);
}
/**
* 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.
*
* Deprecated: 1.72: Use g_callable_info_create_closure() instead
*
* Returns: the native address of the closure or `NULL` on error. The return value
* should be freed by calling g_callable_info_free_closure().
*/
ffi_closure *
g_callable_info_prepare_closure (GICallableInfo *callable_info,
ffi_cif *cif,
GIFFIClosureCallback callback,
gpointer user_data)
{
ffi_closure * closure;
closure = g_callable_info_create_closure (callable_info, cif, callback, user_data);
if (!closure)
{
return NULL;
}
/* Return the native pointer which, on some systems and ffi versions without static exec trampolines,
* points to the same underlying memory as closure, but via an executable-non-writable mapping.
* Deprecated, and kept for backwards compatibility only. Risks segfaults on freeing the closure.
*/
return (ffi_closure *) g_callable_info_get_closure_native_address(callable_info, closure);
}
/**
* g_callable_info_free_closure:
* @callable_info: a callable info from a typelib
* @closure: ffi closure
*
* Deprecated: 1.72: Use g_callable_info_destroy_closure() instead, in
* conjunction with g_callable_info_create_closure().
*
* Should free a ffi_closure returned from g_callable_info_prepare_closure(),
* which may cause a segfault because the native address is returned instead of
* the closure address. May do nothing and leak memory instead of freeing to
* avoid segfaults.
*/
void
g_callable_info_free_closure (GICallableInfo *callable_info,
ffi_closure *closure)
{
#ifdef LEGACY_GIRFFI_FREE
g_callable_info_destroy_closure(callable_info, closure);
#endif
}
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