qemu-patch-raspberry4/qapi/string-output-visitor.c
Eric Blake f755dea79d qapi: Make all visitors supply uint64 callbacks
Our qapi visitor contract supports multiple integer visitors,
but left the type_uint64 visitor as optional (falling back on
type_int64); which in turn can lead to awkward behavior with
numbers larger than INT64_MAX (the user has to be aware of
twos complement, and deal with negatives).

This patch does not address the disparity in handling large
values as negatives.  It merely moves the fallback from uint64
to int64 from the visitor core to the visitors, where the issue
can actually be fixed, by implementing the missing type_uint64()
callbacks on top of the respective type_int64() callbacks, and
with a FIXME comment explaining why that's wrong.

With that done, we now have a type_uint64() callback in every
driver, so we can make it mandatory from the core.  And although
the type_int64() callback can cover the entire valid range of
type_uint{8,16,32} on valid user input, using type_uint64() to
avoid mixed signedness makes more sense.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:55 +01:00

369 lines
10 KiB
C

/*
* String printing Visitor
*
* Copyright Red Hat, Inc. 2012
*
* 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-common.h"
#include "qapi/string-output-visitor.h"
#include "qapi/visitor-impl.h"
#include "qemu/host-utils.h"
#include <math.h>
#include "qemu/range.h"
enum ListMode {
LM_NONE, /* not traversing a list of repeated options */
LM_STARTED, /* start_list() succeeded */
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
};
typedef enum ListMode ListMode;
struct StringOutputVisitor
{
Visitor visitor;
bool human;
GString *string;
bool head;
ListMode list_mode;
union {
int64_t s;
uint64_t u;
} range_start, range_end;
GList *ranges;
};
static StringOutputVisitor *to_sov(Visitor *v)
{
return container_of(v, StringOutputVisitor, visitor);
}
static void string_output_set(StringOutputVisitor *sov, char *string)
{
if (sov->string) {
g_string_free(sov->string, true);
}
sov->string = g_string_new(string);
g_free(string);
}
static void string_output_append(StringOutputVisitor *sov, int64_t a)
{
Range *r = g_malloc0(sizeof(*r));
r->begin = a;
r->end = a + 1;
sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
}
static void string_output_append_range(StringOutputVisitor *sov,
int64_t s, int64_t e)
{
Range *r = g_malloc0(sizeof(*r));
r->begin = s;
r->end = e + 1;
sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
}
static void format_string(StringOutputVisitor *sov, Range *r, bool next,
bool human)
{
if (r->end - r->begin > 1) {
if (human) {
g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
r->begin, r->end - 1);
} else {
g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
r->begin, r->end - 1);
}
} else {
if (human) {
g_string_append_printf(sov->string, "0x%" PRIx64, r->begin);
} else {
g_string_append_printf(sov->string, "%" PRId64, r->begin);
}
}
if (next) {
g_string_append(sov->string, ",");
}
}
static void print_type_int64(Visitor *v, int64_t *obj, const char *name,
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;
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;
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, ")");
}
}
static void print_type_uint64(Visitor *v, uint64_t *obj, const char *name,
Error **errp)
{
/* FIXME: print_type_int64 mishandles values over INT64_MAX */
int64_t i = *obj;
print_type_int64(v, &i, name, errp);
}
static void print_type_size(Visitor *v, uint64_t *obj, const char *name,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
uint64_t div, val;
char *out;
int i;
if (!sov->human) {
out = g_strdup_printf("%"PRIu64, *obj);
string_output_set(sov, out);
return;
}
val = *obj;
/* The exponent (returned in i) minus one gives us
* floor(log2(val * 1024 / 1000). The correction makes us
* switch to the higher power when the integer part is >= 1000.
*/
frexp(val / (1000.0 / 1024.0), &i);
i = (i - 1) / 10;
assert(i < ARRAY_SIZE(suffixes));
div = 1ULL << (i * 10);
out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
(double)val/div, suffixes[i], i ? "iB" : "");
string_output_set(sov, out);
}
static void print_type_bool(Visitor *v, bool *obj, const char *name,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
string_output_set(sov, g_strdup(*obj ? "true" : "false"));
}
static void print_type_str(Visitor *v, char **obj, const char *name,
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);
}
static void print_type_number(Visitor *v, double *obj, const char *name,
Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
string_output_set(sov, g_strdup_printf("%f", *obj));
}
static void
start_list(Visitor *v, const char *name, Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
/* we can't traverse a list in a list */
assert(sov->list_mode == LM_NONE);
sov->list_mode = LM_STARTED;
sov->head = true;
}
static GenericList *
next_list(Visitor *v, GenericList **list, Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
GenericList *ret = NULL;
if (*list) {
if (sov->head) {
ret = *list;
} else {
ret = (*list)->next;
}
if (sov->head) {
if (ret && ret->next == NULL) {
sov->list_mode = LM_NONE;
}
sov->head = false;
} else {
if (ret && ret->next == NULL) {
sov->list_mode = LM_END;
}
}
}
return ret;
}
static void
end_list(Visitor *v, Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
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;
sov->head = true;
}
char *string_output_get_string(StringOutputVisitor *sov)
{
char *string = g_string_free(sov->string, false);
sov->string = NULL;
return string;
}
Visitor *string_output_get_visitor(StringOutputVisitor *sov)
{
return &sov->visitor;
}
static void free_range(void *range, void *dummy)
{
g_free(range);
}
void string_output_visitor_cleanup(StringOutputVisitor *sov)
{
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);
}
StringOutputVisitor *string_output_visitor_new(bool human)
{
StringOutputVisitor *v;
v = g_malloc0(sizeof(*v));
v->string = g_string_new(NULL);
v->human = human;
v->visitor.type_enum = output_type_enum;
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.start_list = start_list;
v->visitor.next_list = next_list;
v->visitor.end_list = end_list;
return v;
}