From 5965243641d797b2270082c5a4eab49cb81fc8f0 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Thu, 11 Mar 2021 17:42:52 +0100
Subject: [PATCH] char: Deprecate backend aliases 'tty' and 'parport'

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'.

Since warnings are not allowed in 'make check' output, we can't test
the deprecated alias any more. Remove it from test-char.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210311164253.338723-3-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 chardev/char.c             | 12 +++++++++++-
 docs/system/deprecated.rst |  6 ++++++
 tests/unit/test-char.c     |  6 ------
 3 files changed, 17 insertions(+), 7 deletions(-)

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;
         }
     }
diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
index 15b9767ba5..dfc12eef51 100644
--- a/docs/system/deprecated.rst
+++ b/docs/system/deprecated.rst
@@ -46,6 +46,12 @@ needs two devices (``-device intel-hda -device hda-duplex``) and
 ``pcspk`` which can be activated using ``-machine
 pcspk-audiodev=<name>``.
 
+``-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/tests/unit/test-char.c b/tests/unit/test-char.c
index 755d54c15e..5b3b48ebac 100644
--- a/tests/unit/test-char.c
+++ b/tests/unit/test-char.c
@@ -1199,12 +1199,6 @@ static void char_serial_test(void)
     /* TODO: add more tests with a pty */
     object_unparent(OBJECT(chr));
 
-    /* test tty alias */
-    qemu_opt_set(opts, "backend", "tty", &error_abort);
-    chr = qemu_chr_new_from_opts(opts, NULL, &error_abort);
-    g_assert_nonnull(chr);
-    object_unparent(OBJECT(chr));
-
     qemu_opts_del(opts);
 }
 #endif