qemu-e2k/qapi/opts-visitor.h

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qapi: introduce OptsVisitor This visitor supports parsing -option [type=]discriminator[,optarg1=val1][,optarg2=val2][,...] style QemuOpts objects into "native" C structures. After defining the type tree in the qapi schema (see below), a root type traversal with this visitor linked to the underlying QemuOpts object will build the "native" C representation of the option. The type tree in the schema, corresponding to an option with a discriminator, must have the following structure: struct scalar member for non-discriminated optarg 1 [*] list for repeating non-discriminated optarg 2 [*] wrapper struct single scalar member union struct for discriminator case 1 scalar member for optarg 3 [*] list for repeating optarg 4 [*] wrapper struct single scalar member scalar member for optarg 5 [*] struct for discriminator case 2 ... The "type" optarg name is fixed for the discriminator role. Its schema representation is "union of structures", and each discriminator value must correspond to a member name in the union. If the option takes no "type" descriminator, then the type subtree rooted at the union must be absent from the schema (including the union itself). Optarg values can be of scalar types str / bool / integers / size. Members marked with [*] may be defined as optional in the schema, describing an optional optarg. Repeating an optarg is supported; its schema representation must be "list of structure with single mandatory scalar member". If an optarg is not described as repeating in the schema (ie. it is defined as a scalar field instead of a list), its last occurrence will take effect. Ordering between differently named optargs is not preserved. A mandatory list (or an optional one which is reported to be available), corresponding to a repeating optarg, has at least one element after successful parsing. v1->v2: - Update opts_type_size() prototype to uint64_t. - Add opts_type_uint64() for options needing the full uint64_t range. (Internals could be extracted to "cutils.c".) - Allow negative values in opts_type_int(). - Rebase to nested Makefiles. v2->v3: - Factor opts_visitor_insert() out of opts_start_struct() and call it separately for opts_root->id if there's any. - Don't require non-negative values in opts_type_int()'s error message. - g_malloc0() may return NULL for zero-sized requests. Support empty structures by requesting 1 byte for them instead. Signed-off-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-07-17 16:17:09 +02:00
/*
* Options Visitor
*
* Copyright Red Hat, Inc. 2012
*
* Author: Laszlo Ersek <lersek@redhat.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#ifndef OPTS_VISITOR_H
#define OPTS_VISITOR_H
#include "qapi-visit-core.h"
#include "qemu-option.h"
typedef struct OptsVisitor OptsVisitor;
/* Contrarily to qemu-option.c::parse_option_number(), OptsVisitor's "int"
* parser relies on strtoll() instead of strtoull(). Consequences:
* - string representations of negative numbers yield negative values,
* - values below INT64_MIN or LLONG_MIN are rejected,
* - values above INT64_MAX or LLONG_MAX are rejected.
*/
OptsVisitor *opts_visitor_new(const QemuOpts *opts);
void opts_visitor_cleanup(OptsVisitor *nv);
Visitor *opts_get_visitor(OptsVisitor *nv);
#endif