/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- * GObject introspection: Callable implementation * * Copyright (C) 2005 Matthias Clasen * Copyright (C) 2008,2009 Red Hat, 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 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 #include #include #include "girepository-private.h" #include "gitypelib-internal.h" #include "girffi.h" /* GICallableInfo functions */ /** * SECTION:gicallableinfo * @title: GICallableInfo * @short_description: Struct representing a callable * * GICallableInfo represents an entity which is callable. * Currently a function (#GIFunctionInfo), virtual function, * (#GIVFuncInfo) or callback (#GICallbackInfo). * * A callable has a list of arguments (#GIArgInfo), a return type, * direction and a flag which decides if it returns null. * * * Struct hierarchy * * GIBaseInfo * +----GICallableInfo * +----GIFunctionInfo * +----GISignalInfo * +----GIVFuncInfo * * */ static guint32 signature_offset (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo*)info; int sigoff = -1; switch (rinfo->type) { case GI_INFO_TYPE_FUNCTION: sigoff = G_STRUCT_OFFSET (FunctionBlob, signature); break; case GI_INFO_TYPE_VFUNC: sigoff = G_STRUCT_OFFSET (VFuncBlob, signature); break; case GI_INFO_TYPE_CALLBACK: sigoff = G_STRUCT_OFFSET (CallbackBlob, signature); break; case GI_INFO_TYPE_SIGNAL: sigoff = G_STRUCT_OFFSET (SignalBlob, signature); break; default: g_assert_not_reached (); } if (sigoff >= 0) return *(guint32 *)&rinfo->typelib->data[rinfo->offset + sigoff]; return 0; } /** * g_callable_info_can_throw_gerror: * @info: a #GICallableInfo * * TODO * * Since: 1.34 * Returns: %TRUE if this #GICallableInfo can throw a #GError */ gboolean g_callable_info_can_throw_gerror (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo*)info; SignatureBlob *signature; signature = (SignatureBlob *)&rinfo->typelib->data[signature_offset (info)]; if (signature->throws) return TRUE; /* Functions and VFuncs store "throws" in their own blobs. * This info was additionally added to the SignatureBlob * to support the other callables. For Functions and VFuncs, * also check their legacy flag for compatibility. */ switch (rinfo->type) { case GI_INFO_TYPE_FUNCTION: { FunctionBlob *blob; blob = (FunctionBlob *)&rinfo->typelib->data[rinfo->offset]; return blob->throws; } case GI_INFO_TYPE_VFUNC: { VFuncBlob *blob; blob = (VFuncBlob *)&rinfo->typelib->data[rinfo->offset]; return blob->throws; } case GI_INFO_TYPE_CALLBACK: case GI_INFO_TYPE_SIGNAL: return FALSE; default: g_assert_not_reached (); } } /** * g_callable_info_is_method: * @info: a #GICallableInfo * * Determines if the callable info is a method. For #GIVFuncInfos, * #GICallbackInfos, and #GISignalInfos, * this is always true. Otherwise, this looks at the %GI_FUNCTION_IS_METHOD * flag on the #GIFunctionInfo. * * Concretely, this function returns whether g_callable_info_get_n_args() * matches the number of arguments in the raw C method. For methods, there * is one more C argument than is exposed by introspection: the "self" * or "this" object. * * Returns: %TRUE if @info is a method, %FALSE otherwise * Since: 1.34 */ gboolean g_callable_info_is_method (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo*)info; switch (rinfo->type) { case GI_INFO_TYPE_FUNCTION: { FunctionBlob *blob; blob = (FunctionBlob *)&rinfo->typelib->data[rinfo->offset]; return (!blob->constructor && !blob->is_static); } case GI_INFO_TYPE_VFUNC: case GI_INFO_TYPE_SIGNAL: return TRUE; case GI_INFO_TYPE_CALLBACK: return FALSE; default: g_assert_not_reached (); } } /** * g_callable_info_get_return_type: * @info: a #GICallableInfo * * Obtain the return type of a callable item as a #GITypeInfo. * * Returns: (transfer full): the #GITypeInfo. Free the struct by calling * g_base_info_unref() when done. */ GITypeInfo * g_callable_info_get_return_type (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo *)info; guint32 offset; g_return_val_if_fail (info != NULL, NULL); g_return_val_if_fail (GI_IS_CALLABLE_INFO (info), NULL); offset = signature_offset (info); return _g_type_info_new ((GIBaseInfo*)info, rinfo->typelib, offset); } /** * g_callable_info_load_return_type: * @info: a #GICallableInfo * @type: (out caller-allocates): Initialized with return type of @info * * Obtain information about a return value of callable; this * function is a variant of g_callable_info_get_return_type() designed for stack * allocation. * * The initialized @type must not be referenced after @info is deallocated. */ void g_callable_info_load_return_type (GICallableInfo *info, GITypeInfo *type) { GIRealInfo *rinfo = (GIRealInfo *)info; guint32 offset; g_return_if_fail (info != NULL); g_return_if_fail (GI_IS_CALLABLE_INFO (info)); offset = signature_offset (info); _g_type_info_init (type, (GIBaseInfo*)info, rinfo->typelib, offset); } /** * g_callable_info_may_return_null: * @info: a #GICallableInfo * * See if a callable could return %NULL. * * Returns: %TRUE if callable could return %NULL */ gboolean g_callable_info_may_return_null (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo *)info; SignatureBlob *blob; g_return_val_if_fail (info != NULL, FALSE); g_return_val_if_fail (GI_IS_CALLABLE_INFO (info), FALSE); blob = (SignatureBlob *)&rinfo->typelib->data[signature_offset (info)]; return blob->may_return_null; } /** * g_callable_info_skip_return: * @info: a #GICallableInfo * * See if a callable's return value is only useful in C. * * Returns: %TRUE if return value is only useful in C. */ gboolean g_callable_info_skip_return (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo *)info; SignatureBlob *blob; g_return_val_if_fail (info != NULL, FALSE); g_return_val_if_fail (GI_IS_CALLABLE_INFO (info), FALSE); blob = (SignatureBlob *)&rinfo->typelib->data[signature_offset (info)]; return blob->skip_return; } /** * g_callable_info_get_caller_owns: * @info: a #GICallableInfo * * See whether the caller owns the return value of this callable. * #GITransfer contains a list of possible transfer values. * * Returns: the transfer mode for the return value of the callable */ GITransfer g_callable_info_get_caller_owns (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo*) info; SignatureBlob *blob; g_return_val_if_fail (info != NULL, -1); g_return_val_if_fail (GI_IS_CALLABLE_INFO (info), -1); blob = (SignatureBlob *)&rinfo->typelib->data[signature_offset (info)]; if (blob->caller_owns_return_value) return GI_TRANSFER_EVERYTHING; else if (blob->caller_owns_return_container) return GI_TRANSFER_CONTAINER; else return GI_TRANSFER_NOTHING; } /** * g_callable_info_get_instance_ownership_transfer: * @info: a #GICallableInfo * * Obtains the ownership transfer for the instance argument. * #GITransfer contains a list of possible transfer values. * * Since: 1.42 * Returns: the transfer mode of the instance argument */ GITransfer g_callable_info_get_instance_ownership_transfer (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo*) info; SignatureBlob *blob; g_return_val_if_fail (info != NULL, -1); g_return_val_if_fail (GI_IS_CALLABLE_INFO (info), -1); blob = (SignatureBlob *)&rinfo->typelib->data[signature_offset (info)]; if (blob->instance_transfer_ownership) return GI_TRANSFER_EVERYTHING; else return GI_TRANSFER_NOTHING; } /** * g_callable_info_get_n_args: * @info: a #GICallableInfo * * Obtain the number of arguments (both IN and OUT) for this callable. * * Returns: The number of arguments this callable expects. */ gint g_callable_info_get_n_args (GICallableInfo *info) { GIRealInfo *rinfo = (GIRealInfo *)info; gint offset; SignatureBlob *blob; g_return_val_if_fail (info != NULL, -1); g_return_val_if_fail (GI_IS_CALLABLE_INFO (info), -1); offset = signature_offset (info); blob = (SignatureBlob *)&rinfo->typelib->data[offset]; return blob->n_arguments; } /** * g_callable_info_get_arg: * @info: a #GICallableInfo * @n: the argument index to fetch * * Obtain information about a particular argument of this callable. * * Returns: (transfer full): the #GIArgInfo. Free it with * g_base_info_unref() when done. */ GIArgInfo * g_callable_info_get_arg (GICallableInfo *info, gint n) { GIRealInfo *rinfo = (GIRealInfo *)info; Header *header; gint offset; g_return_val_if_fail (info != NULL, NULL); g_return_val_if_fail (GI_IS_CALLABLE_INFO (info), NULL); offset = signature_offset (info); header = (Header *)rinfo->typelib->data; return (GIArgInfo *) g_info_new (GI_INFO_TYPE_ARG, (GIBaseInfo*)info, rinfo->typelib, offset + header->signature_blob_size + n * header->arg_blob_size); } /** * g_callable_info_load_arg: * @info: a #GICallableInfo * @n: the argument index to fetch * @arg: (out caller-allocates): Initialize with argument number @n * * Obtain information about a particular argument of this callable; this * function is a variant of g_callable_info_get_arg() designed for stack * allocation. * * The initialized @arg must not be referenced after @info is deallocated. */ void g_callable_info_load_arg (GICallableInfo *info, gint n, GIArgInfo *arg) { GIRealInfo *rinfo = (GIRealInfo *)info; Header *header; gint offset; g_return_if_fail (info != NULL); g_return_if_fail (GI_IS_CALLABLE_INFO (info)); offset = signature_offset (info); header = (Header *)rinfo->typelib->data; _g_info_init ((GIRealInfo*)arg, GI_INFO_TYPE_ARG, rinfo->repository, (GIBaseInfo*)info, rinfo->typelib, offset + header->signature_blob_size + n * header->arg_blob_size); } /** * g_callable_info_get_return_attribute: * @info: a #GICallableInfo * @name: a freeform string naming an attribute * * Retrieve an arbitrary attribute associated with the return value. * * Returns: The value of the attribute, or %NULL if no such attribute exists */ const gchar * g_callable_info_get_return_attribute (GICallableInfo *info, const gchar *name) { GIAttributeIter iter = { 0, }; gchar *curname, *curvalue; while (g_callable_info_iterate_return_attributes (info, &iter, &curname, &curvalue)) { if (g_strcmp0 (name, curname) == 0) return (const gchar*) curvalue; } return NULL; } /** * g_callable_info_iterate_return_attributes: * @info: a #GICallableInfo * @iterator: (inout): a #GIAttributeIter structure, must be initialized; see below * @name: (out) (transfer none): Returned name, must not be freed * @value: (out) (transfer none): Returned name, must not be freed * * Iterate over all attributes associated with the return value. The * iterator structure is typically stack allocated, and must have its * first member initialized to %NULL. * * Both the @name and @value should be treated as constants * and must not be freed. * * See g_base_info_iterate_attributes() for an example of how to use a * similar API. * * Returns: %TRUE if there are more attributes */ gboolean g_callable_info_iterate_return_attributes (GICallableInfo *info, GIAttributeIter *iterator, char **name, char **value) { GIRealInfo *rinfo = (GIRealInfo *)info; Header *header = (Header *)rinfo->typelib->data; AttributeBlob *next, *after; guint32 blob_offset; after = (AttributeBlob *) &rinfo->typelib->data[header->attributes + header->n_attributes * header->attribute_blob_size]; blob_offset = signature_offset (info); if (iterator->data != NULL) next = (AttributeBlob *) iterator->data; else next = _attribute_blob_find_first (info, blob_offset); if (next == NULL || next->offset != blob_offset || next >= after) return FALSE; *name = (gchar*) g_typelib_get_string (rinfo->typelib, next->name); *value = (gchar*) g_typelib_get_string (rinfo->typelib, next->value); iterator->data = next + 1; return TRUE; } /** * gi_type_tag_extract_ffi_return_value: * @return_tag: #GITypeTag of the return value * @interface_type: #GIInfoType of the underlying interface type * @ffi_value: pointer to #GIFFIReturnValue union containing the return value * from ffi_call() * @arg: (out caller-allocates): pointer to an allocated #GIArgument * * Extract the correct bits from an ffi_arg return value into * GIArgument: https://bugzilla.gnome.org/show_bug.cgi?id=665152 * * Also see ffi_call3 * - the storage requirements for return values are "special". * * The @interface_type argument only applies if @return_tag is * %GI_TYPE_TAG_INTERFACE. Otherwise it is ignored. * * Since: 1.72 */ void gi_type_tag_extract_ffi_return_value (GITypeTag return_tag, GIInfoType interface_type, GIFFIReturnValue *ffi_value, GIArgument *arg) { switch (return_tag) { case GI_TYPE_TAG_INT8: arg->v_int8 = (gint8) ffi_value->v_long; break; case GI_TYPE_TAG_UINT8: arg->v_uint8 = (guint8) ffi_value->v_ulong; break; case GI_TYPE_TAG_INT16: arg->v_int16 = (gint16) ffi_value->v_long; break; case GI_TYPE_TAG_UINT16: arg->v_uint16 = (guint16) ffi_value->v_ulong; break; case GI_TYPE_TAG_INT32: arg->v_int32 = (gint32) ffi_value->v_long; break; case GI_TYPE_TAG_UINT32: case GI_TYPE_TAG_BOOLEAN: case GI_TYPE_TAG_UNICHAR: arg->v_uint32 = (guint32) ffi_value->v_ulong; break; case GI_TYPE_TAG_INT64: arg->v_int64 = (gint64) ffi_value->v_int64; break; case GI_TYPE_TAG_UINT64: arg->v_uint64 = (guint64) ffi_value->v_uint64; break; case GI_TYPE_TAG_FLOAT: arg->v_float = ffi_value->v_float; break; case GI_TYPE_TAG_DOUBLE: arg->v_double = ffi_value->v_double; break; case GI_TYPE_TAG_INTERFACE: switch(interface_type) { case GI_INFO_TYPE_ENUM: case GI_INFO_TYPE_FLAGS: arg->v_int32 = (gint32) ffi_value->v_long; break; default: arg->v_pointer = (gpointer) ffi_value->v_pointer; break; } break; default: arg->v_pointer = (gpointer) ffi_value->v_pointer; break; } } /** * gi_type_info_extract_ffi_return_value: * @return_info: #GITypeInfo describing the return type * @ffi_value: pointer to #GIFFIReturnValue union containing the return value * from ffi_call() * @arg: (out caller-allocates): pointer to an allocated #GIArgument * * Extract the correct bits from an ffi_arg return value into * GIArgument: https://bugzilla.gnome.org/show_bug.cgi?id=665152 * * Also see ffi_call3 * - the storage requirements for return values are "special". */ void gi_type_info_extract_ffi_return_value (GITypeInfo *return_info, GIFFIReturnValue *ffi_value, GIArgument *arg) { GITypeTag return_tag = g_type_info_get_tag (return_info); GIInfoType interface_type = GI_INFO_TYPE_INVALID; if (return_tag == GI_TYPE_TAG_INTERFACE) { GIBaseInfo *interface_info = g_type_info_get_interface (return_info); interface_type = g_base_info_get_type (interface_info); g_base_info_unref (interface_info); } return gi_type_tag_extract_ffi_return_value (return_tag, interface_type, ffi_value, arg); } /** * g_callable_info_invoke: * @info: TODO * @function: TODO * @in_args: (array length=n_in_args): TODO * @n_in_args: TODO * @out_args: (array length=n_out_args): TODO * @n_out_args: TODO * @return_value: TODO * @is_method: TODO * @throws: TODO * @error: TODO * * TODO */ gboolean g_callable_info_invoke (GIFunctionInfo *info, gpointer function, const GIArgument *in_args, int n_in_args, const GIArgument *out_args, int n_out_args, GIArgument *return_value, gboolean is_method, gboolean throws, GError **error) { ffi_cif cif; ffi_type *rtype; ffi_type **atypes; GITypeInfo *tinfo; GITypeInfo *rinfo; GITypeTag rtag; GIArgInfo *ainfo; gint n_args, n_invoke_args, in_pos, out_pos, i; gpointer *args; gboolean success = FALSE; GError *local_error = NULL; gpointer error_address = &local_error; GIFFIReturnValue ffi_return_value; gpointer return_value_p; /* Will point inside the union return_value */ rinfo = g_callable_info_get_return_type ((GICallableInfo *)info); rtype = g_type_info_get_ffi_type (rinfo); rtag = g_type_info_get_tag(rinfo); in_pos = 0; out_pos = 0; n_args = g_callable_info_get_n_args ((GICallableInfo *)info); if (is_method) { if (n_in_args == 0) { g_set_error (error, G_INVOKE_ERROR, G_INVOKE_ERROR_ARGUMENT_MISMATCH, "Too few \"in\" arguments (handling this)"); goto out; } n_invoke_args = n_args+1; in_pos++; } else n_invoke_args = n_args; if (throws) /* Add an argument for the GError */ n_invoke_args ++; atypes = g_alloca (sizeof (ffi_type*) * n_invoke_args); args = g_alloca (sizeof (gpointer) * n_invoke_args); if (is_method) { atypes[0] = &ffi_type_pointer; args[0] = (gpointer) &in_args[0]; } for (i = 0; i < n_args; i++) { int offset = (is_method ? 1 : 0); ainfo = g_callable_info_get_arg ((GICallableInfo *)info, i); switch (g_arg_info_get_direction (ainfo)) { case GI_DIRECTION_IN: tinfo = g_arg_info_get_type (ainfo); atypes[i+offset] = g_type_info_get_ffi_type (tinfo); g_base_info_unref ((GIBaseInfo *)ainfo); g_base_info_unref ((GIBaseInfo *)tinfo); if (in_pos >= n_in_args) { g_set_error (error, G_INVOKE_ERROR, G_INVOKE_ERROR_ARGUMENT_MISMATCH, "Too few \"in\" arguments (handling in)"); goto out; } args[i+offset] = (gpointer)&in_args[in_pos]; in_pos++; break; case GI_DIRECTION_OUT: atypes[i+offset] = &ffi_type_pointer; g_base_info_unref ((GIBaseInfo *)ainfo); if (out_pos >= n_out_args) { g_set_error (error, G_INVOKE_ERROR, G_INVOKE_ERROR_ARGUMENT_MISMATCH, "Too few \"out\" arguments (handling out)"); goto out; } args[i+offset] = (gpointer)&out_args[out_pos]; out_pos++; break; case GI_DIRECTION_INOUT: atypes[i+offset] = &ffi_type_pointer; g_base_info_unref ((GIBaseInfo *)ainfo); if (in_pos >= n_in_args) { g_set_error (error, G_INVOKE_ERROR, G_INVOKE_ERROR_ARGUMENT_MISMATCH, "Too few \"in\" arguments (handling inout)"); goto out; } if (out_pos >= n_out_args) { g_set_error (error, G_INVOKE_ERROR, G_INVOKE_ERROR_ARGUMENT_MISMATCH, "Too few \"out\" arguments (handling inout)"); goto out; } args[i+offset] = (gpointer)&in_args[in_pos]; in_pos++; out_pos++; break; default: g_base_info_unref ((GIBaseInfo *)ainfo); g_assert_not_reached (); } } if (throws) { args[n_invoke_args - 1] = &error_address; atypes[n_invoke_args - 1] = &ffi_type_pointer; } if (in_pos < n_in_args) { g_set_error (error, G_INVOKE_ERROR, G_INVOKE_ERROR_ARGUMENT_MISMATCH, "Too many \"in\" arguments (at end)"); goto out; } if (out_pos < n_out_args) { g_set_error (error, G_INVOKE_ERROR, G_INVOKE_ERROR_ARGUMENT_MISMATCH, "Too many \"out\" arguments (at end)"); goto out; } if (ffi_prep_cif (&cif, FFI_DEFAULT_ABI, n_invoke_args, rtype, atypes) != FFI_OK) goto out; g_return_val_if_fail (return_value, FALSE); /* See comment for GIFFIReturnValue above */ switch (rtag) { case GI_TYPE_TAG_FLOAT: return_value_p = &ffi_return_value.v_float; break; case GI_TYPE_TAG_DOUBLE: return_value_p = &ffi_return_value.v_double; break; case GI_TYPE_TAG_INT64: case GI_TYPE_TAG_UINT64: return_value_p = &ffi_return_value.v_uint64; break; default: return_value_p = &ffi_return_value.v_long; } ffi_call (&cif, function, return_value_p, args); if (local_error) { g_propagate_error (error, local_error); success = FALSE; } else { gi_type_info_extract_ffi_return_value (rinfo, &ffi_return_value, return_value); success = TRUE; } out: g_base_info_unref ((GIBaseInfo *)rinfo); return success; }