[PATCH 1/2] qemu-option: move help handling to get_opt_name_value

[Paolo Bonzini <pbonzini@redhat.com>]

Right now, help options are parsed normally and then checked
specially in opt_validate. but only if coming from
qemu_opts_parse or qemu_opts_parse_noisily.
Move the check from opt_validate to the common workhorses
of qemu_opts_parse and qemu_opts_parse_noisily, opts_do_parse
and get_opt_name_value.

As a result, opts_parse and opts_do_parse do not return an error anymore
when help is requested---just like qemu_opts_parse_noisily.

This will come in handy in the next patch, which will
raise a warning for "-object memory-backend-ram,share"
("flag" option with no =on/=off part) but not for
"-object memory-backend-ram,help".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 util/qemu-option.c | 40 ++++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/util/qemu-option.c b/util/qemu-option.c
index acefbc23fa..61fc96f9dd 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -504,17 +504,13 @@ static QemuOpt *opt_create(QemuOpts *opts, const char *name, char *value,
     return opt;
 }
 
-static bool opt_validate(QemuOpt *opt, bool *help_wanted,
-                         Error **errp)
+static bool opt_validate(QemuOpt *opt, Error **errp)
 {
     const QemuOptDesc *desc;
 
     desc = find_desc_by_name(opt->opts->list->desc, opt->name);
     if (!desc && !opts_accepts_any(opt->opts)) {
         error_setg(errp, QERR_INVALID_PARAMETER, opt->name);
-        if (help_wanted && is_help_option(opt->name)) {
-            *help_wanted = true;
-        }
         return false;
     }
 
@@ -531,7 +527,7 @@ bool qemu_opt_set(QemuOpts *opts, const char *name, const char *value,
 {
     QemuOpt *opt = opt_create(opts, name, g_strdup(value), false);
 
-    if (!opt_validate(opt, NULL, errp)) {
+    if (!opt_validate(opt, errp)) {
         qemu_opt_del(opt);
         return false;
     }
@@ -767,16 +763,18 @@ void qemu_opts_print(QemuOpts *opts, const char *separator)
 
 static const char *get_opt_name_value(const char *params,
                                       const char *firstname,
+                                      bool *help_wanted,
                                       char **name, char **value)
 {
-    const char *p, *pe, *pc;
-
-    pe = strchr(params, '=');
-    pc = strchr(params, ',');
+    const char *p;
+    size_t len;
 
-    if (!pe || (pc && pc < pe)) {
+    len = strcspn(params, "=,");
+    if (params[len] != '=') {
         /* found "foo,more" */
-        if (firstname) {
+        if (help_wanted && starts_with_help_option(params) == len) {
+            *help_wanted = true;
+        } else if (firstname) {
             /* implicitly named first option */
             *name = g_strdup(firstname);
             p = get_opt_value(params, value);
@@ -814,7 +812,10 @@ static bool opts_do_parse(QemuOpts *opts, const char *params,
     QemuOpt *opt;
 
     for (p = params; *p;) {
-        p = get_opt_name_value(p, firstname, &option, &value);
+        p = get_opt_name_value(p, firstname, help_wanted, &option, &value);
+        if (help_wanted && *help_wanted) {
+            return false;
+        }
         firstname = NULL;
 
         if (!strcmp(option, "id")) {
@@ -825,7 +826,7 @@ static bool opts_do_parse(QemuOpts *opts, const char *params,
 
         opt = opt_create(opts, option, value, prepend);
         g_free(option);
-        if (!opt_validate(opt, help_wanted, errp)) {
+        if (!opt_validate(opt, errp)) {
             qemu_opt_del(opt);
             return false;
         }
@@ -840,7 +841,7 @@ static char *opts_parse_id(const char *params)
     char *name, *value;
 
     for (p = params; *p;) {
-        p = get_opt_name_value(p, NULL, &name, &value);
+        p = get_opt_name_value(p, NULL, NULL, &name, &value);
         if (!strcmp(name, "id")) {
             g_free(name);
             return value;
@@ -856,11 +857,10 @@ bool has_help_option(const char *params)
 {
     const char *p;
     char *name, *value;
-    bool ret;
+    bool ret = false;
 
     for (p = params; *p;) {
-        p = get_opt_name_value(p, NULL, &name, &value);
-        ret = is_help_option(name);
+        p = get_opt_name_value(p, NULL, &ret, &name, &value);
         g_free(name);
         g_free(value);
         if (ret) {
@@ -946,10 +946,10 @@ QemuOpts *qemu_opts_parse_noisily(QemuOptsList *list, const char *params,
     bool help_wanted = false;
 
     opts = opts_parse(list, params, permit_abbrev, false, &help_wanted, &err);
-    if (err) {
+    if (!opts) {
+        assert(!!err + !!help_wanted == 1);
         if (help_wanted) {
             qemu_opts_print_help(list, true);
-            error_free(err);
         } else {
             error_report_err(err);
         }
-- 
2.26.2