qemu/qapi/string-output-visitor.c
Stefan Hajnoczi ff32bb5347 string-output-visitor: show structs as "<omitted>"
StringOutputVisitor crashes when it visits a struct because
->start_struct() is NULL.

Show "<omitted>" instead of crashing. This is necessary because the
virtio-blk-pci iothread-vq-mapping parameter that I'd like to introduce
soon is a list of IOThreadMapping structs.

This patch is a quick fix to solve the crash, but the long-term solution
is replacing StringOutputVisitor with something that can handle the full
gamut of values in QEMU.

Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20231212134934.500289-1-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-12-21 22:49:28 +01:00

406 lines
11 KiB
C

/*
* String printing Visitor
*
* Copyright Red Hat, Inc. 2012-2016
*
* Author: Paolo Bonzini <pbonzini@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/osdep.h"
#include "qemu/cutils.h"
#include "qapi/string-output-visitor.h"
#include "qapi/visitor-impl.h"
#include <math.h>
#include "qemu/range.h"
enum ListMode {
LM_NONE, /* not traversing a list of repeated options */
LM_STARTED, /* next_list() ready to be called */
LM_IN_PROGRESS, /* 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, /* 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. */
LM_END, /* next_list() called, about to see last element. */
};
typedef enum ListMode ListMode;
struct StringOutputVisitor
{
Visitor visitor;
bool human;
GString *string;
char **result;
ListMode list_mode;
union {
int64_t s;
uint64_t u;
} range_start, range_end;
GList *ranges;
void *list; /* Only needed for sanity checking the caller */
};
static StringOutputVisitor *to_sov(Visitor *v)
{
return container_of(v, StringOutputVisitor, visitor);
}
static void string_output_set(StringOutputVisitor *sov, char *string)
{
switch (sov->list_mode) {
case LM_STARTED:
sov->list_mode = LM_IN_PROGRESS;
/* fall through */
case LM_NONE:
if (sov->string) {
g_string_free(sov->string, true);
}
sov->string = g_string_new(string);
g_free(string);
break;
case LM_IN_PROGRESS:
case LM_END:
g_string_append(sov->string, ", ");
g_string_append(sov->string, string);
break;
default:
abort();
}
}
static void string_output_append(StringOutputVisitor *sov, int64_t a)
{
Range *r = g_malloc0(sizeof(*r));
range_set_bounds(r, a, a);
sov->ranges = range_list_insert(sov->ranges, r);
}
static void string_output_append_range(StringOutputVisitor *sov,
int64_t s, int64_t e)
{
Range *r = g_malloc0(sizeof(*r));
range_set_bounds(r, s, e);
sov->ranges = range_list_insert(sov->ranges, r);
}
static void format_string(StringOutputVisitor *sov, Range *r, bool next,
bool human)
{
if (range_lob(r) != range_upb(r)) {
if (human) {
g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
range_lob(r), range_upb(r));
} else {
g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
range_lob(r), range_upb(r));
}
} else {
if (human) {
g_string_append_printf(sov->string, "0x%" PRIx64, range_lob(r));
} else {
g_string_append_printf(sov->string, "%" PRId64, range_lob(r));
}
}
if (next) {
g_string_append(sov->string, ",");
}
}
static bool print_type_int64(Visitor *v, const char *name, int64_t *obj,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
GList *l;
switch (sov->list_mode) {
case LM_NONE:
string_output_append(sov, *obj);
break;
case LM_STARTED:
sov->range_start.s = *obj;
sov->range_end.s = *obj;
sov->list_mode = LM_IN_PROGRESS;
return true;
case LM_IN_PROGRESS:
if (sov->range_end.s + 1 == *obj) {
sov->range_end.s++;
} else {
if (sov->range_start.s == sov->range_end.s) {
string_output_append(sov, sov->range_end.s);
} else {
assert(sov->range_start.s < sov->range_end.s);
string_output_append_range(sov, sov->range_start.s,
sov->range_end.s);
}
sov->range_start.s = *obj;
sov->range_end.s = *obj;
}
return true;
case LM_END:
if (sov->range_end.s + 1 == *obj) {
sov->range_end.s++;
assert(sov->range_start.s < sov->range_end.s);
string_output_append_range(sov, sov->range_start.s,
sov->range_end.s);
} else {
if (sov->range_start.s == sov->range_end.s) {
string_output_append(sov, sov->range_end.s);
} else {
assert(sov->range_start.s < sov->range_end.s);
string_output_append_range(sov, sov->range_start.s,
sov->range_end.s);
}
string_output_append(sov, *obj);
}
break;
default:
abort();
}
l = sov->ranges;
while (l) {
Range *r = l->data;
format_string(sov, r, l->next != NULL, false);
l = l->next;
}
if (sov->human) {
l = sov->ranges;
g_string_append(sov->string, " (");
while (l) {
Range *r = l->data;
format_string(sov, r, l->next != NULL, true);
l = l->next;
}
g_string_append(sov->string, ")");
}
return true;
}
static bool print_type_uint64(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
/* FIXME: print_type_int64 mishandles values over INT64_MAX */
int64_t i = *obj;
return print_type_int64(v, name, &i, errp);
}
static bool print_type_size(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
uint64_t val;
char *out, *psize;
if (!sov->human) {
out = g_strdup_printf("%"PRIu64, *obj);
string_output_set(sov, out);
return true;
}
val = *obj;
psize = size_to_str(val);
out = g_strdup_printf("%"PRIu64" (%s)", val, psize);
string_output_set(sov, out);
g_free(psize);
return true;
}
static bool print_type_bool(Visitor *v, const char *name, bool *obj,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
string_output_set(sov, g_strdup(*obj ? "true" : "false"));
return true;
}
static bool print_type_str(Visitor *v, const char *name, char **obj,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
char *out;
if (sov->human) {
out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
} else {
out = g_strdup(*obj ? *obj : "");
}
string_output_set(sov, out);
return true;
}
static bool print_type_number(Visitor *v, const char *name, double *obj,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
string_output_set(sov, g_strdup_printf("%.17g", *obj));
return true;
}
static bool print_type_null(Visitor *v, const char *name, QNull **obj,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
char *out;
if (sov->human) {
out = g_strdup("<null>");
} else {
out = g_strdup("");
}
string_output_set(sov, out);
return true;
}
static bool start_struct(Visitor *v, const char *name, void **obj,
size_t size, Error **errp)
{
return true;
}
static void end_struct(Visitor *v, void **obj)
{
StringOutputVisitor *sov = to_sov(v);
/* TODO actually print struct fields */
string_output_set(sov, g_strdup("<omitted>"));
}
static bool
start_list(Visitor *v, const char *name, GenericList **list, size_t size,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
/* we can't traverse a list in a list */
assert(sov->list_mode == LM_NONE);
/* We don't support visits without a list */
assert(list);
sov->list = list;
/* List handling is only needed if there are at least two elements */
if (*list && (*list)->next) {
sov->list_mode = LM_STARTED;
}
return true;
}
static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
{
StringOutputVisitor *sov = to_sov(v);
GenericList *ret = tail->next;
if (ret && !ret->next) {
sov->list_mode = LM_END;
}
return ret;
}
static void end_list(Visitor *v, void **obj)
{
StringOutputVisitor *sov = to_sov(v);
assert(sov->list == obj);
assert(sov->list_mode == LM_STARTED ||
sov->list_mode == LM_END ||
sov->list_mode == LM_NONE ||
sov->list_mode == LM_IN_PROGRESS);
sov->list_mode = LM_NONE;
}
static void string_output_complete(Visitor *v, void *opaque)
{
StringOutputVisitor *sov = to_sov(v);
assert(opaque == sov->result);
*sov->result = g_string_free(sov->string, false);
sov->string = NULL;
}
static void free_range(void *range, void *dummy)
{
g_free(range);
}
static void string_output_free(Visitor *v)
{
StringOutputVisitor *sov = to_sov(v);
if (sov->string) {
g_string_free(sov->string, true);
}
g_list_foreach(sov->ranges, free_range, NULL);
g_list_free(sov->ranges);
g_free(sov);
}
Visitor *string_output_visitor_new(bool human, char **result)
{
StringOutputVisitor *v;
v = g_malloc0(sizeof(*v));
v->string = g_string_new(NULL);
v->human = human;
v->result = result;
*result = NULL;
v->visitor.type = VISITOR_OUTPUT;
v->visitor.type_int64 = print_type_int64;
v->visitor.type_uint64 = print_type_uint64;
v->visitor.type_size = print_type_size;
v->visitor.type_bool = print_type_bool;
v->visitor.type_str = print_type_str;
v->visitor.type_number = print_type_number;
v->visitor.type_null = print_type_null;
v->visitor.start_struct = start_struct;
v->visitor.end_struct = end_struct;
v->visitor.start_list = start_list;
v->visitor.next_list = next_list;
v->visitor.end_list = end_list;
v->visitor.complete = string_output_complete;
v->visitor.free = string_output_free;
return &v->visitor;
}