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qemu/qapi/opts-visitor.c
Eric Blake 5cdc8831a7 qapi: Simplify visits of optional fields 
None of the visitor callbacks would set an error when testing
if an optional field was present; make this part of the interface
contract by eliminating the errp argument.

The resulting generated code has a nice diff:

|-    visit_optional(v, &has_fdset_id, "fdset-id", &err);
|-    if (err) {
|-        goto out;
|-    }
|+    visit_optional(v, &has_fdset_id, "fdset-id");
|     if (has_fdset_id) {
|         visit_type_int(v, &fdset_id, "fdset-id", &err);
|         if (err) {
|             goto out;
|         }
|     }

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-9-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:29 +01:00

558 lines
15 KiB
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/*
* Options Visitor
*
* Copyright Red Hat, Inc. 2012, 2013
*
* 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.
*
*/
#include "qemu-common.h"
#include "qapi/qmp/qerror.h"
#include "qapi/opts-visitor.h"
#include "qemu/queue.h"
#include "qemu/option_int.h"
#include "qapi/visitor-impl.h"
enum ListMode
{
LM_NONE, /* not traversing a list of repeated options */
LM_STARTED, /* opts_start_list() succeeded */
LM_IN_PROGRESS, /* opts_next_list() has been called.
*
* Generating the next list link will consume the most
* recently parsed QemuOpt instance of the repeated
* option.
*
* Parsing a value into the list link will examine the
* next QemuOpt instance of the repeated option, and
* possibly enter LM_SIGNED_INTERVAL or
* LM_UNSIGNED_INTERVAL.
*/
LM_SIGNED_INTERVAL, /* opts_next_list() has been called.
*
* Generating the next list link will consume the most
* recently stored element from the signed interval,
* parsed from the most recent QemuOpt instance of the
* repeated option. This may consume QemuOpt itself
* and return to LM_IN_PROGRESS.
*
* Parsing a value into the list link will store the
* next element of the signed interval.
*/
LM_UNSIGNED_INTERVAL /* Same as above, only for an unsigned interval. */
};
typedef enum ListMode ListMode;
struct OptsVisitor
{
Visitor visitor;
/* Ownership remains with opts_visitor_new()'s caller. */
const QemuOpts *opts_root;
unsigned depth;
/* Non-null iff depth is positive. Each key is a QemuOpt name. Each value
* is a non-empty GQueue, enumerating all QemuOpt occurrences with that
* name. */
GHashTable *unprocessed_opts;
/* The list currently being traversed with opts_start_list() /
* opts_next_list(). The list must have a struct element type in the
* schema, with a single mandatory scalar member. */
ListMode list_mode;
GQueue *repeated_opts;
/* When parsing a list of repeating options as integers, values of the form
* "a-b", representing a closed interval, are allowed. Elements in the
* range are generated individually.
*/
union {
int64_t s;
uint64_t u;
} range_next, range_limit;
/* If "opts_root->id" is set, reinstantiate it as a fake QemuOpt for
* uniformity. Only its "name" and "str" fields are set. "fake_id_opt" does
* not survive or escape the OptsVisitor object.
*/
QemuOpt *fake_id_opt;
};
static void
destroy_list(gpointer list)
{
g_queue_free(list);
}
static void
opts_visitor_insert(GHashTable *unprocessed_opts, const QemuOpt *opt)
{
GQueue *list;
list = g_hash_table_lookup(unprocessed_opts, opt->name);
if (list == NULL) {
list = g_queue_new();
/* GHashTable will never try to free the keys -- we supply NULL as
* "key_destroy_func" in opts_start_struct(). Thus cast away key
* const-ness in order to suppress gcc's warning.
*/
g_hash_table_insert(unprocessed_opts, (gpointer)opt->name, list);
}
/* Similarly, destroy_list() doesn't call g_queue_free_full(). */
g_queue_push_tail(list, (gpointer)opt);
}
static void
opts_start_struct(Visitor *v, void **obj, const char *kind,
const char *name, size_t size, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
const QemuOpt *opt;
if (obj) {
*obj = g_malloc0(size > 0 ? size : 1);
}
if (ov->depth++ > 0) {
return;
}
ov->unprocessed_opts = g_hash_table_new_full(&g_str_hash, &g_str_equal,
NULL, &destroy_list);
QTAILQ_FOREACH(opt, &ov->opts_root->head, next) {
/* ensured by qemu-option.c::opts_do_parse() */
assert(strcmp(opt->name, "id") != 0);
opts_visitor_insert(ov->unprocessed_opts, opt);
}
if (ov->opts_root->id != NULL) {
ov->fake_id_opt = g_malloc0(sizeof *ov->fake_id_opt);
ov->fake_id_opt->name = g_strdup("id");
ov->fake_id_opt->str = g_strdup(ov->opts_root->id);
opts_visitor_insert(ov->unprocessed_opts, ov->fake_id_opt);
}
}
static gboolean
ghr_true(gpointer ign_key, gpointer ign_value, gpointer ign_user_data)
{
return TRUE;
}
static void
opts_end_struct(Visitor *v, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
GQueue *any;
if (--ov->depth > 0) {
return;
}
/* we should have processed all (distinct) QemuOpt instances */
any = g_hash_table_find(ov->unprocessed_opts, &ghr_true, NULL);
if (any) {
const QemuOpt *first;
first = g_queue_peek_head(any);
error_setg(errp, QERR_INVALID_PARAMETER, first->name);
}
g_hash_table_destroy(ov->unprocessed_opts);
ov->unprocessed_opts = NULL;
if (ov->fake_id_opt) {
g_free(ov->fake_id_opt->name);
g_free(ov->fake_id_opt->str);
g_free(ov->fake_id_opt);
}
ov->fake_id_opt = NULL;
}
static GQueue *
lookup_distinct(const OptsVisitor *ov, const char *name, Error **errp)
{
GQueue *list;
list = g_hash_table_lookup(ov->unprocessed_opts, name);
if (!list) {
error_setg(errp, QERR_MISSING_PARAMETER, name);
}
return list;
}
static void
opts_start_list(Visitor *v, const char *name, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
/* we can't traverse a list in a list */
assert(ov->list_mode == LM_NONE);
ov->repeated_opts = lookup_distinct(ov, name, errp);
if (ov->repeated_opts != NULL) {
ov->list_mode = LM_STARTED;
}
}
static GenericList *
opts_next_list(Visitor *v, GenericList **list, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
GenericList **link;
switch (ov->list_mode) {
case LM_STARTED:
ov->list_mode = LM_IN_PROGRESS;
link = list;
break;
case LM_SIGNED_INTERVAL:
case LM_UNSIGNED_INTERVAL:
link = &(*list)->next;
if (ov->list_mode == LM_SIGNED_INTERVAL) {
if (ov->range_next.s < ov->range_limit.s) {
++ov->range_next.s;
break;
}
} else if (ov->range_next.u < ov->range_limit.u) {
++ov->range_next.u;
break;
}
ov->list_mode = LM_IN_PROGRESS;
/* range has been completed, fall through in order to pop option */
case LM_IN_PROGRESS: {
const QemuOpt *opt;
opt = g_queue_pop_head(ov->repeated_opts);
if (g_queue_is_empty(ov->repeated_opts)) {
g_hash_table_remove(ov->unprocessed_opts, opt->name);
return NULL;
}
link = &(*list)->next;
break;
}
default:
abort();
}
*link = g_malloc0(sizeof **link);
return *link;
}
static void
opts_end_list(Visitor *v, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
assert(ov->list_mode == LM_STARTED ||
ov->list_mode == LM_IN_PROGRESS ||
ov->list_mode == LM_SIGNED_INTERVAL ||
ov->list_mode == LM_UNSIGNED_INTERVAL);
ov->repeated_opts = NULL;
ov->list_mode = LM_NONE;
}
static const QemuOpt *
lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp)
{
if (ov->list_mode == LM_NONE) {
GQueue *list;
/* the last occurrence of any QemuOpt takes effect when queried by name
*/
list = lookup_distinct(ov, name, errp);
return list ? g_queue_peek_tail(list) : NULL;
}
assert(ov->list_mode == LM_IN_PROGRESS);
return g_queue_peek_head(ov->repeated_opts);
}
static void
processed(OptsVisitor *ov, const char *name)
{
if (ov->list_mode == LM_NONE) {
g_hash_table_remove(ov->unprocessed_opts, name);
return;
}
assert(ov->list_mode == LM_IN_PROGRESS);
/* do nothing */
}
static void
opts_type_str(Visitor *v, char **obj, const char *name, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
const QemuOpt *opt;
opt = lookup_scalar(ov, name, errp);
if (!opt) {
return;
}
*obj = g_strdup(opt->str ? opt->str : "");
processed(ov, name);
}
/* mimics qemu-option.c::parse_option_bool() */
static void
opts_type_bool(Visitor *v, bool *obj, const char *name, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
const QemuOpt *opt;
opt = lookup_scalar(ov, name, errp);
if (!opt) {
return;
}
if (opt->str) {
if (strcmp(opt->str, "on") == 0 ||
strcmp(opt->str, "yes") == 0 ||
strcmp(opt->str, "y") == 0) {
*obj = true;
} else if (strcmp(opt->str, "off") == 0 ||
strcmp(opt->str, "no") == 0 ||
strcmp(opt->str, "n") == 0) {
*obj = false;
} else {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
"on|yes|y|off|no|n");
return;
}
} else {
*obj = true;
}
processed(ov, name);
}
static void
opts_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
const QemuOpt *opt;
const char *str;
long long val;
char *endptr;
if (ov->list_mode == LM_SIGNED_INTERVAL) {
*obj = ov->range_next.s;
return;
}
opt = lookup_scalar(ov, name, errp);
if (!opt) {
return;
}
str = opt->str ? opt->str : "";
/* we've gotten past lookup_scalar() */
assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
errno = 0;
val = strtoll(str, &endptr, 0);
if (errno == 0 && endptr > str && INT64_MIN <= val && val <= INT64_MAX) {
if (*endptr == '\0') {
*obj = val;
processed(ov, name);
return;
}
if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
long long val2;
str = endptr + 1;
val2 = strtoll(str, &endptr, 0);
if (errno == 0 && endptr > str && *endptr == '\0' &&
INT64_MIN <= val2 && val2 <= INT64_MAX && val <= val2 &&
(val > INT64_MAX - OPTS_VISITOR_RANGE_MAX ||
val2 < val + OPTS_VISITOR_RANGE_MAX)) {
ov->range_next.s = val;
ov->range_limit.s = val2;
ov->list_mode = LM_SIGNED_INTERVAL;
/* as if entering on the top */
*obj = ov->range_next.s;
return;
}
}
}
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
(ov->list_mode == LM_NONE) ? "an int64 value" :
"an int64 value or range");
}
static void
opts_type_uint64(Visitor *v, uint64_t *obj, const char *name, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
const QemuOpt *opt;
const char *str;
unsigned long long val;
char *endptr;
if (ov->list_mode == LM_UNSIGNED_INTERVAL) {
*obj = ov->range_next.u;
return;
}
opt = lookup_scalar(ov, name, errp);
if (!opt) {
return;
}
str = opt->str;
/* we've gotten past lookup_scalar() */
assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
if (parse_uint(str, &val, &endptr, 0) == 0 && val <= UINT64_MAX) {
if (*endptr == '\0') {
*obj = val;
processed(ov, name);
return;
}
if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
unsigned long long val2;
str = endptr + 1;
if (parse_uint_full(str, &val2, 0) == 0 &&
val2 <= UINT64_MAX && val <= val2 &&
val2 - val < OPTS_VISITOR_RANGE_MAX) {
ov->range_next.u = val;
ov->range_limit.u = val2;
ov->list_mode = LM_UNSIGNED_INTERVAL;
/* as if entering on the top */
*obj = ov->range_next.u;
return;
}
}
}
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
(ov->list_mode == LM_NONE) ? "a uint64 value" :
"a uint64 value or range");
}
static void
opts_type_size(Visitor *v, uint64_t *obj, const char *name, Error **errp)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
const QemuOpt *opt;
int64_t val;
char *endptr;
opt = lookup_scalar(ov, name, errp);
if (!opt) {
return;
}
val = qemu_strtosz_suffix(opt->str ? opt->str : "", &endptr,
QEMU_STRTOSZ_DEFSUFFIX_B);
if (val < 0 || *endptr) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
"a size value representible as a non-negative int64");
return;
}
*obj = val;
processed(ov, name);
}
static void
opts_optional(Visitor *v, bool *present, const char *name)
{
OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
/* we only support a single mandatory scalar field in a list node */
assert(ov->list_mode == LM_NONE);
*present = (lookup_distinct(ov, name, NULL) != NULL);
}
OptsVisitor *
opts_visitor_new(const QemuOpts *opts)
{
OptsVisitor *ov;
ov = g_malloc0(sizeof *ov);
ov->visitor.start_struct = &opts_start_struct;
ov->visitor.end_struct = &opts_end_struct;
ov->visitor.start_list = &opts_start_list;
ov->visitor.next_list = &opts_next_list;
ov->visitor.end_list = &opts_end_list;
/* input_type_enum() covers both "normal" enums and union discriminators.
* The union discriminator field is always generated as "type"; it should
* match the "type" QemuOpt child of any QemuOpts.
*
* input_type_enum() will remove the looked-up key from the
* "unprocessed_opts" hash even if the lookup fails, because the removal is
* done earlier in opts_type_str(). This should be harmless.
*/
ov->visitor.type_enum = &input_type_enum;
ov->visitor.type_int = &opts_type_int;
ov->visitor.type_uint64 = &opts_type_uint64;
ov->visitor.type_size = &opts_type_size;
ov->visitor.type_bool = &opts_type_bool;
ov->visitor.type_str = &opts_type_str;
/* type_number() is not filled in, but this is not the first visitor to
* skip some mandatory methods... */
ov->visitor.optional = &opts_optional;
ov->opts_root = opts;
return ov;
}
void
opts_visitor_cleanup(OptsVisitor *ov)
{
if (ov->unprocessed_opts != NULL) {
g_hash_table_destroy(ov->unprocessed_opts);
}
g_free(ov->fake_id_opt);
g_free(ov);
}
Visitor *
opts_get_visitor(OptsVisitor *ov)
{
return &ov->visitor;
}
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