[PATCH 07/13] char: Add qemu_chr_parse_cli_dict/str()

[Kevin Wolf]

This adds a function that parses a command line definition of a
character device into ChardevOptions, which can then be passed to
qemu_chr_new_cli().

You can start both from a string (for actual CLI) or from a QDict, which
is not only the intermediate representation after calling the keyval
parser, but also what HMP handlers receive.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/chardev/char.h | 30 ++++++++++++++++++++++++++++
 chardev/char.c         | 45 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/include/chardev/char.h b/include/chardev/char.h
index c0944f5828..5cd46207f6 100644
--- a/include/chardev/char.h
+++ b/include/chardev/char.h
@@ -94,6 +94,36 @@ Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
  */
 Chardev *qemu_chr_new_cli(ChardevOptions *options, Error **errp);
 
+/**
+ * qemu_chr_parse_cli_dict:
+ * @args: Options defining a new character device
+ * @help: true if help should be printed instead of returning ChardevOptions
+ *
+ * Parses the given command line option QDict into ChardevOptions, using
+ * qemu_chr_translate_legacy_options() to maintain compatibility with
+ * legacy command line syntax.
+ *
+ * Returns: On successful conversion, a ChardevOptions object containing the
+ * requested options. NULL and @errp is unchanged if help was requested and
+ * printed. NULL and @errp is set in error cases.
+ */
+ChardevOptions *qemu_chr_parse_cli_dict(QDict *args, bool help,
+                                        Error **errp);
+
+/**
+ * qemu_chr_parse_cli_str:
+ * @optarg: Command line argument defining a new character device
+ *
+ * Parses the given command line option into ChardevOptions, using
+ * qemu_chr_translate_legacy_options() to maintain compatibility with
+ * legacy command line syntax.
+ *
+ * Returns: On successful conversion, a ChardevOptions object containing the
+ * requested options. NULL and @errp is unchanged if help was requested and
+ * printed. NULL and @errp is set in error cases.
+ */
+ChardevOptions *qemu_chr_parse_cli_str(const char *optarg, Error **errp);
+
 /**
  * qemu_chr_translate_legacy_options:
  * @args: Character device creation options as returned by the keyval parser
diff --git a/chardev/char.c b/chardev/char.c
index 99feaae275..a5d6be9dc8 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -32,8 +32,10 @@
 #include "chardev/char.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-char.h"
+#include "qapi/qapi-visit-char.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qerror.h"
+#include "qapi/qobject-input-visitor.h"
 #include "sysemu/replay.h"
 #include "qemu/help_option.h"
 #include "qemu/module.h"
@@ -1106,6 +1108,49 @@ Chardev *qemu_chr_new_cli(ChardevOptions *options, Error 
**errp)
     return chardev_new_qapi(options->id, options->backend, errp);
 }
 
+ChardevOptions *qemu_chr_parse_cli_dict(QDict *args, bool help,
+                                        Error **errp)
+{
+    Visitor *v;
+    ChardevOptions *chr_options;
+
+    qemu_chr_translate_legacy_options(args);
+
+    if (help) {
+        if (qdict_haskey(args, "type")) {
+            /* TODO Print help based on the QAPI schema */
+            qemu_opts_print_help(&qemu_chardev_opts, true);
+        } else {
+            qemu_chr_print_types();
+        }
+        return NULL;
+    }
+
+    v = qobject_input_visitor_new_keyval(QOBJECT(args));
+    visit_type_ChardevOptions(v, NULL, &chr_options, errp);
+    visit_free(v);
+
+    return chr_options;
+}
+
+ChardevOptions *qemu_chr_parse_cli_str(const char *optarg, Error **errp)
+{
+    ERRP_GUARD();
+    QDict *args;
+    ChardevOptions *chr_options;
+    bool help;
+
+    args = keyval_parse(optarg, "backend", &help, errp);
+    if (!args) {
+        return NULL;
+    }
+
+    chr_options = qemu_chr_parse_cli_dict(args, help, errp);
+    qobject_unref(args);
+
+    return chr_options;
+}
+
 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
                                   Error **errp)
 {
-- 
2.28.0