[Qemu-devel] [PATCH v23 08/32] add convert functions between QEMUOptionParameter to QemuOpts

[Chunyan Liu <cyliu@suse.com>]

Add two temp convert functions between QEMUOptionParameter to QemuOpts,
so that next patch can use it. It will simplify later patch for easier
review. And will be finally removed after all backend drivers switch to
QemuOpts.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
---
Finally not following Eric's suggestion of adding char tmp[] to QemuOptList
to store stringized uint value, but choosing g_strdup and add flag 'mallocd'
to QemuOptList to indicate free the mallocd space, since:
1. there could be many unit options need to store, so, adding char tmp[] in
QemuOptList couldn't solve problem, but should add char tmp[] in QemuOptDesc.
Then, for those not unit type, the char tmp[] space is wasted.
2. in later qemu_opts_append() function, since it accept both QemuOptsList and
QEMUOptionParameter as input, for QEMUOptionParamter, it will temp converted
to QemuOpts, then append to result list; after that, the converted QemuOpts
should be freed. It's risky that some memory that the result list members
point to might be freed.
So, simply g_strdup is safer, the only thing is to free in this case.

 include/qemu/option.h |   8 +++
 util/qemu-option.c    | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 162 insertions(+)

diff --git a/include/qemu/option.h b/include/qemu/option.h
index fbf5dc2..fd6f075 100644
--- a/include/qemu/option.h
+++ b/include/qemu/option.h
@@ -103,6 +103,11 @@ typedef struct QemuOptDesc {
 } QemuOptDesc;
 
 struct QemuOptsList {
+    /* FIXME: Temp used for QEMUOptionParamter->QemuOpts conversion to
+     * indicate free memory. Will remove after all drivers switch to QemuOpts.
+     */
+    bool mallocd;
+
     const char *name;
     const char *implied_opt_name;
     bool merge_lists;  /* Merge multiple uses of option into a single list? */
@@ -167,5 +172,8 @@ void qemu_opts_print(QemuOpts *opts);
 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,
                       int abort_on_failure);
 void qemu_opts_print_help(QemuOptsList *list);
+void qemu_opts_free(QemuOptsList *list);
+QEMUOptionParameter *opts_to_params(QemuOpts *opts);
+QemuOptsList *params_to_opts(QEMUOptionParameter *list);
 
 #endif
diff --git a/util/qemu-option.c b/util/qemu-option.c
index 315a7bb..4bdcfbf 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -1323,3 +1323,157 @@ int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,
     loc_pop(&loc);
     return rc;
 }
+
+static size_t count_opts_list(QemuOptsList *list)
+{
+    QemuOptDesc *desc = NULL;
+    size_t num_opts = 0;
+
+    if (!list) {
+        return 0;
+    }
+
+    desc = list->desc;
+    while (desc && desc->name) {
+        num_opts++;
+        desc++;
+    }
+
+    return num_opts;
+}
+
+/* Convert QEMUOptionParameter to QemuOpts
+ * FIXME: this function will be removed after all drivers
+ * switch to QemuOpts
+ */
+QemuOptsList *params_to_opts(QEMUOptionParameter *list)
+{
+    QemuOptsList *opts = NULL;
+    size_t num_opts, i = 0;
+
+    if (!list) {
+        return NULL;
+    }
+
+    num_opts = count_option_parameters(list);
+    opts = g_malloc0(sizeof(QemuOptsList) +
+                     (num_opts + 1) * sizeof(QemuOptDesc));
+    QTAILQ_INIT(&opts->head);
+    /* (const char *) members will point to malloced space and need to free */
+    opts->mallocd = true;
+
+    while (list && list->name) {
+        opts->desc[i].name = g_strdup(list->name);
+        opts->desc[i].help = g_strdup(list->help);
+        switch (list->type) {
+        case OPT_FLAG:
+            opts->desc[i].type = QEMU_OPT_BOOL;
+            opts->desc[i].def_value_str =
+                g_strdup(list->value.n ? "on" : "off");
+            break;
+
+        case OPT_NUMBER:
+            opts->desc[i].type = QEMU_OPT_NUMBER;
+            if (list->value.n) {
+                opts->desc[i].def_value_str =
+                    g_strdup_printf("%" PRIu64, list->value.n);
+            }
+            break;
+
+        case OPT_SIZE:
+            opts->desc[i].type = QEMU_OPT_SIZE;
+            if (list->value.n) {
+                opts->desc[i].def_value_str =
+                    g_strdup_printf("%" PRIu64, list->value.n);
+            }
+            break;
+
+        case OPT_STRING:
+            opts->desc[i].type = QEMU_OPT_STRING;
+            opts->desc[i].def_value_str = g_strdup(list->value.s);
+            break;
+        }
+
+        i++;
+        list++;
+        opts->desc[i].name = NULL;
+    }
+
+    return opts;
+}
+
+/* convert QemuOpts to QEMUOptionParamter
+ * Note: result QEMUOptionParameter has shorter lifetime than
+ * input QemuOpts.
+ * FIXME: this function will be removed after all drivers
+ * switch to QemuOpts
+ */
+QEMUOptionParameter *opts_to_params(QemuOpts *opts)
+{
+    QEMUOptionParameter *dest = NULL;
+    QemuOptDesc *desc;
+    size_t num_opts, i = 0;
+    const char *tmp;
+
+    if (!opts || !opts->list || !opts->list->desc) {
+        return NULL;
+    }
+    assert(!opts_accepts_any(opts));
+
+    num_opts = count_opts_list(opts->list);
+    dest = g_malloc0((num_opts + 1) * sizeof(QEMUOptionParameter));
+
+    desc = opts->list->desc;
+    while (desc && desc->name) {
+        dest[i].name = desc->name;
+        dest[i].help = desc->help;
+        switch (desc->type) {
+        case QEMU_OPT_STRING:
+            dest[i].type = OPT_STRING;
+            tmp = qemu_opt_get(opts, desc->name);
+            dest[i].value.s = g_strdup(tmp);
+            break;
+
+        case QEMU_OPT_BOOL:
+            dest[i].type = OPT_FLAG;
+            dest[i].value.n = qemu_opt_get_bool(opts, desc->name, 0) ? 1 : 0;
+            break;
+
+        case QEMU_OPT_NUMBER:
+            dest[i].type = OPT_NUMBER;
+            dest[i].value.n = qemu_opt_get_number(opts, desc->name, 0);
+            break;
+
+        case QEMU_OPT_SIZE:
+            dest[i].type = OPT_SIZE;
+            dest[i].value.n = qemu_opt_get_size(opts, desc->name, 0);
+            break;
+        }
+
+        i++;
+        desc++;
+        dest[i].name = NULL;
+    }
+
+    return dest;
+}
+
+void qemu_opts_free(QemuOptsList *list)
+{
+    /* List members point to new malloced space and need to free.
+     * FIXME:
+     * Introduced for QEMUOptionParamter->QemuOpts conversion.
+     * Will remove after all drivers switch to QemuOpts.
+     */
+    if (list && list->mallocd) {
+        QemuOptDesc *desc = list->desc;
+        while (desc && desc->name) {
+            g_free((char *)desc->name);
+            g_free((char *)desc->help);
+            g_free((char *)desc->def_value_str);
+            desc++;
+        }
+    }
+
+    g_free(list);
+}
-- 
1.7.12.4