[PATCH v2 2/3] char: Deprecate backend aliases 'tty' and 'parport'

[Kevin Wolf <kwolf@redhat.com>]

QAPI doesn't know the aliases 'tty' and 'parport' and there is no
reason to prefer them to the real names of the backends 'serial' and
'parallel'.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
---
 docs/system/deprecated.rst |  6 ++++++
 chardev/char.c             | 12 +++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
index 3e9e3a26f6..11da79ea5b 100644
--- a/docs/system/deprecated.rst
+++ b/docs/system/deprecated.rst
@@ -75,6 +75,12 @@ The ``pretty=on|off`` switch has no effect for HMP monitors, but is
 silently ignored. Using the switch with HMP monitors will become an
 error in the future.
 
+``-chardev`` backend aliases ``tty`` and ``parport`` (since 6.0)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+``tty`` and ``parport`` are aliases that will be removed. Instead, the
+actual backend names ``serial`` and ``parallel`` should be used.
+
 RISC-V ``-bios`` (since 5.1)
 ''''''''''''''''''''''''''''
 
diff --git a/chardev/char.c b/chardev/char.c
index dd925cf9a4..7be9579dd8 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -534,9 +534,10 @@ static const ChardevClass *char_get_class(const char *driver, Error **errp)
     return cc;
 }
 
-static const struct ChardevAlias {
+static struct ChardevAlias {
     const char *typename;
     const char *alias;
+    bool deprecation_warning_printed;
 } chardev_alias_table[] = {
 #ifdef HAVE_CHARDEV_PARPORT
     { "parallel", "parport" },
@@ -584,6 +585,10 @@ help_string_append(const char *name, bool is_cli_alias, void *opaque)
 {
     GString *str = opaque;
 
+    if (is_cli_alias) {
+        return;
+    }
+
     g_string_append_printf(str, "\n  %s", name);
 }
 
@@ -592,6 +597,11 @@ static const char *chardev_alias_translate(const char *name)
     int i;
     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
+            if (!chardev_alias_table[i].deprecation_warning_printed) {
+                warn_report("The alias '%s' is deprecated, use '%s' instead",
+                            name, chardev_alias_table[i].typename);
+                chardev_alias_table[i].deprecation_warning_printed = true;
+            }
             return chardev_alias_table[i].typename;
         }
     }
-- 
2.29.2