[PATCH v6 0/5] string list functions

[PATCH v6 0/5] string list functions

[Philippe Mathieu-Daudé]

Hi Markus,

Here are the patches I queued until you told me you'd
object to the CamelCase filename strList.[ch].

Steve, please take over ;)

Since v5:
- Cover files in MAINTAINERS
- Complete @docstring mentioning g_auto.

v5: https://lore.kernel.org/qemu-devel/1708638470-114846-3-git-send-email-steven.sistare@oracle.com/

Steve Sistare (5):
  util: str_split
  qapi: QAPI_LIST_LENGTH
  util: strv_from_strList
  util: strList unit tests
  migration: simplify exec migration functions

 MAINTAINERS               |  2 +
 include/monitor/hmp.h     |  1 -
 include/qapi/util.h       | 13 +++++++
 include/qemu/strList.h    | 33 ++++++++++++++++
 migration/exec.c          | 57 ++++------------------------
 monitor/hmp-cmds.c        | 19 ----------
 net/net-hmp-cmds.c        |  3 +-
 stats/stats-hmp-cmds.c    |  3 +-
 tests/unit/test-strList.c | 80 +++++++++++++++++++++++++++++++++++++++
 util/strList.c            | 38 +++++++++++++++++++
 tests/unit/meson.build    |  1 +
 util/meson.build          |  1 +
 12 files changed, 180 insertions(+), 71 deletions(-)
 create mode 100644 include/qemu/strList.h
 create mode 100644 tests/unit/test-strList.c
 create mode 100644 util/strList.c

-- 
2.41.0

[PATCH v6 1/5] util: str_split

[Philippe Mathieu-Daudé]

From: Steve Sistare <steven.sistare@oracle.com>

Generalize hmp_split_at_comma() to take any delimiter string, rename
as str_split(), and move it to util/strList.c.

No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <1708638470-114846-2-git-send-email-steven.sistare@oracle.com>
[PMD: Cover new files in 'QAPI' section in MAINTAINERS]
Message-ID: <d126c937-c705-476f-baa5-d5e258780cc0@oracle.com>
---
 MAINTAINERS            |  2 ++
 include/monitor/hmp.h  |  1 -
 include/qemu/strList.h | 25 +++++++++++++++++++++++++
 monitor/hmp-cmds.c     | 19 -------------------
 net/net-hmp-cmds.c     |  3 ++-
 stats/stats-hmp-cmds.c |  3 ++-
 util/strList.c         | 24 ++++++++++++++++++++++++
 util/meson.build       |  1 +
 8 files changed, 56 insertions(+), 22 deletions(-)
 create mode 100644 include/qemu/strList.h
 create mode 100644 util/strList.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 992799171f..7970d34cdd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3196,6 +3196,8 @@ X: qapi/*.json
 F: include/qapi/
 X: include/qapi/qmp/
 F: include/qapi/qmp/dispatch.h
+F: include/qemu/strList.h
+F: util/strList.c
 F: tests/qapi-schema/
 F: tests/unit/test-*-visitor.c
 F: tests/unit/test-qapi-*.c
diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
index 13f9a2dedb..2df661ee3a 100644
--- a/include/monitor/hmp.h
+++ b/include/monitor/hmp.h
@@ -19,7 +19,6 @@
 
 bool hmp_handle_error(Monitor *mon, Error *err);
 void hmp_help_cmd(Monitor *mon, const char *name);
-strList *hmp_split_at_comma(const char *str);
 
 void hmp_info_name(Monitor *mon, const QDict *qdict);
 void hmp_info_version(Monitor *mon, const QDict *qdict);
diff --git a/include/qemu/strList.h b/include/qemu/strList.h
new file mode 100644
index 0000000000..4e2e78624e
--- /dev/null
+++ b/include/qemu/strList.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2022 - 2024 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_STR_LIST_H
+#define QEMU_STR_LIST_H
+
+#include "qapi/qapi-builtin-types.h"
+
+/*
+ * Split @str into a strList using the delimiter string @delim.
+ * The delimiter is not included in the result.
+ * Return NULL if @str is NULL or an empty string.
+ * A leading, trailing, or consecutive delimiter produces an
+ * empty string at that position in the output.
+ * All strings are g_strdup'd, and the result can be freed
+ * using qapi_free_strList, or by declaring a local variable
+ * with g_autoptr(strList).
+ */
+strList *str_split(const char *str, const char *delim);
+
+#endif
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 871898ac46..66b68a0ad3 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -38,25 +38,6 @@ bool hmp_handle_error(Monitor *mon, Error *err)
     return false;
 }
 
-/*
- * Split @str at comma.
- * A null @str defaults to "".
- */
-strList *hmp_split_at_comma(const char *str)
-{
-    char **split = g_strsplit(str ?: "", ",", -1);
-    strList *res = NULL;
-    strList **tail = &res;
-    int i;
-
-    for (i = 0; split[i]; i++) {
-        QAPI_LIST_APPEND(tail, split[i]);
-    }
-
-    g_free(split);
-    return res;
-}
-
 void hmp_info_name(Monitor *mon, const QDict *qdict)
 {
     NameInfo *info;
diff --git a/net/net-hmp-cmds.c b/net/net-hmp-cmds.c
index 41d326bf5f..969cdd1e4d 100644
--- a/net/net-hmp-cmds.c
+++ b/net/net-hmp-cmds.c
@@ -26,6 +26,7 @@
 #include "qemu/config-file.h"
 #include "qemu/help_option.h"
 #include "qemu/option.h"
+#include "qemu/strList.h"
 
 void hmp_info_network(Monitor *mon, const QDict *qdict)
 {
@@ -72,7 +73,7 @@ void hmp_announce_self(Monitor *mon, const QDict *qdict)
                                             migrate_announce_params());
 
     qapi_free_strList(params->interfaces);
-    params->interfaces = hmp_split_at_comma(interfaces_str);
+    params->interfaces = str_split(interfaces_str, ",");
     params->has_interfaces = params->interfaces != NULL;
     params->id = g_strdup(id);
     qmp_announce_self(params, NULL);
diff --git a/stats/stats-hmp-cmds.c b/stats/stats-hmp-cmds.c
index 1f91bf8bd5..62db8c613c 100644
--- a/stats/stats-hmp-cmds.c
+++ b/stats/stats-hmp-cmds.c
@@ -10,6 +10,7 @@
 #include "monitor/hmp.h"
 #include "monitor/monitor.h"
 #include "qemu/cutils.h"
+#include "qemu/strList.h"
 #include "hw/core/cpu.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/error.h"
@@ -176,7 +177,7 @@ static StatsFilter *stats_filter(StatsTarget target, const char *names,
             request->provider = provider_idx;
             if (names && !g_str_equal(names, "*")) {
                 request->has_names = true;
-                request->names = hmp_split_at_comma(names);
+                request->names = str_split(names, ",");
             }
             QAPI_LIST_PREPEND(request_list, request);
         }
diff --git a/util/strList.c b/util/strList.c
new file mode 100644
index 0000000000..7588c7c797
--- /dev/null
+++ b/util/strList.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2023 Red Hat, Inc.
+ * Copyright (c) 2022 - 2024 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/strList.h"
+
+strList *str_split(const char *str, const char *delim)
+{
+    g_autofree char **split = g_strsplit(str ?: "", delim, -1);
+    strList *res = NULL;
+    strList **tail = &res;
+    int i;
+
+    for (i = 0; split[i]; i++) {
+        QAPI_LIST_APPEND(tail, split[i]);
+    }
+
+    return res;
+}
diff --git a/util/meson.build b/util/meson.build
index 0ef9886be0..bd125a4094 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -1,4 +1,5 @@
 util_ss.add(files('osdep.c', 'cutils.c', 'unicode.c', 'qemu-timer-common.c'))
+util_ss.add(files('strList.c'))
 util_ss.add(files('thread-context.c'), numa)
 if not config_host_data.get('CONFIG_ATOMIC64')
   util_ss.add(files('atomic64.c'))
-- 
2.41.0

[PATCH v6 2/5] qapi: QAPI_LIST_LENGTH

[Philippe Mathieu-Daudé]

From: Steve Sistare <steven.sistare@oracle.com>

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <1708638470-114846-3-git-send-email-steven.sistare@oracle.com>
---
 include/qapi/util.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/qapi/util.h b/include/qapi/util.h
index 81a2b13a33..20dfea8a54 100644
--- a/include/qapi/util.h
+++ b/include/qapi/util.h
@@ -56,4 +56,17 @@ int parse_qapi_name(const char *name, bool complete);
     (tail) = &(*(tail))->next; \
 } while (0)
 
+/*
+ * For any GenericList @list, return its length.
+ */
+#define QAPI_LIST_LENGTH(list)                                      \
+    ({                                                              \
+        size_t _len = 0;                                            \
+        typeof(list) _tail;                                         \
+        for (_tail = list; _tail != NULL; _tail = _tail->next) {    \
+            _len++;                                                 \
+        }                                                           \
+        _len;                                                       \
+    })
+
 #endif
-- 
2.41.0

[PATCH v6 3/5] util: strv_from_strList

[Philippe Mathieu-Daudé]

From: Steve Sistare <steven.sistare@oracle.com>

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <1708638470-114846-4-git-send-email-steven.sistare@oracle.com>
Message-ID: <d126c937-c705-476f-baa5-d5e258780cc0@oracle.com>
---
 include/qemu/strList.h |  8 ++++++++
 util/strList.c         | 14 ++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/include/qemu/strList.h b/include/qemu/strList.h
index 4e2e78624e..b13bd539c3 100644
--- a/include/qemu/strList.h
+++ b/include/qemu/strList.h
@@ -22,4 +22,12 @@
  */
 strList *str_split(const char *str, const char *delim);
 
+/*
+ * Produce and return a NULL-terminated array of strings from @list.
+ * The result is g_malloc'd and all strings are g_strdup'd.  The result
+ * can be freed using g_strfreev, or by declaring a local variable with
+ * g_auto(GStrv).
+ */
+char **strv_from_strList(const strList *list);
+
 #endif
diff --git a/util/strList.c b/util/strList.c
index 7588c7c797..6da6762c08 100644
--- a/util/strList.c
+++ b/util/strList.c
@@ -22,3 +22,17 @@ strList *str_split(const char *str, const char *delim)
 
     return res;
 }
+
+char **strv_from_strList(const strList *list)
+{
+    const strList *tail;
+    int i = 0;
+    char **argv = g_new(char *, QAPI_LIST_LENGTH(list) + 1);
+
+    for (tail = list; tail != NULL; tail = tail->next) {
+        argv[i++] = g_strdup(tail->value);
+    }
+    argv[i] = NULL;
+
+    return argv;
+}
-- 
2.41.0

[PATCH v6 4/5] util: strList unit tests

[Philippe Mathieu-Daudé]

From: Steve Sistare <steven.sistare@oracle.com>

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <1708638470-114846-5-git-send-email-steven.sistare@oracle.com>
---
 tests/unit/test-strList.c | 80 +++++++++++++++++++++++++++++++++++++++
 tests/unit/meson.build    |  1 +
 2 files changed, 81 insertions(+)
 create mode 100644 tests/unit/test-strList.c

diff --git a/tests/unit/test-strList.c b/tests/unit/test-strList.c
new file mode 100644
index 0000000000..40af6b2ad1
--- /dev/null
+++ b/tests/unit/test-strList.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2022 - 2024 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/strList.h"
+
+static strList *make_list(int length)
+{
+    strList *head = 0, *list, **prev = &head;
+
+    while (length--) {
+        list = *prev = g_new0(strList, 1);
+        list->value = g_strdup("aaa");
+        prev = &list->next;
+    }
+    return head;
+}
+
+static void test_length(void)
+{
+    strList *list;
+    int i;
+
+    for (i = 0; i < 5; i++) {
+        list = make_list(i);
+        g_assert_cmpint(i, ==, QAPI_LIST_LENGTH(list));
+        qapi_free_strList(list);
+    }
+}
+
+struct {
+    const char *string;
+    const char *delim;
+    const char *argv[5];
+} list_data[] = {
+    { NULL, ",", { NULL } },
+    { "", ",", { NULL } },
+    { "a", ",", { "a", NULL } },
+    { "a,b", ",", { "a", "b", NULL } },
+    { "a,b,c", ",", { "a", "b", "c", NULL } },
+    { "first last", " ", { "first", "last", NULL } },
+    { "a:", ":", { "a", "", NULL } },
+    { "a::b", ":", { "a", "", "b", NULL } },
+    { ":", ":", { "", "", NULL } },
+    { ":a", ":", { "", "a", NULL } },
+    { "::a", ":", { "", "", "a", NULL } },
+};
+
+static void test_strv(void)
+{
+    int i, j;
+    const char **expect;
+    strList *list;
+    char **argv;
+
+    for (i = 0; i < ARRAY_SIZE(list_data); i++) {
+        expect = list_data[i].argv;
+        list = str_split(list_data[i].string, list_data[i].delim);
+        argv = strv_from_strList(list);
+        qapi_free_strList(list);
+        for (j = 0; expect[j] && argv[j]; j++) {
+            g_assert_cmpstr(expect[j], ==, argv[j]);
+        }
+        g_assert_null(expect[j]);
+        g_assert_null(argv[j]);
+        g_strfreev(argv);
+    }
+}
+
+int main(int argc, char **argv)
+{
+    g_test_init(&argc, &argv, NULL);
+    g_test_add_func("/test-string/length", test_length);
+    g_test_add_func("/test-string/strv", test_strv);
+    return g_test_run();
+}
diff --git a/tests/unit/meson.build b/tests/unit/meson.build
index cae925c132..9984860f0f 100644
--- a/tests/unit/meson.build
+++ b/tests/unit/meson.build
@@ -35,6 +35,7 @@ tests = {
   'test-rcu-simpleq': [],
   'test-rcu-tailq': [],
   'test-rcu-slist': [],
+  'test-strList': [],
   'test-qdist': [],
   'test-qht': [],
   'test-qtree': [],
-- 
2.41.0

[PATCH v6 5/5] migration: simplify exec migration functions

[Philippe Mathieu-Daudé]

From: Steve Sistare <steven.sistare@oracle.com>

Simplify the exec migration code by using list utility functions.

As a side effect, this also fixes a minor memory leak.  On function return,
"g_auto(GStrv) argv" frees argv and each element, which is wrong, because
the function does not own the individual elements.  To compensate, the code
uses g_steal_pointer which NULLs argv and prevents the destructor from
running, but argv is leaked.

Fixes: cbab4face57b ("migration: convert exec backend ...")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Message-ID: <1708638470-114846-6-git-send-email-steven.sistare@oracle.com>
---
 migration/exec.c | 57 +++++++-----------------------------------------
 1 file changed, 8 insertions(+), 49 deletions(-)

diff --git a/migration/exec.c b/migration/exec.c
index 47d2f3b8fb..15184096ac 100644
--- a/migration/exec.c
+++ b/migration/exec.c
@@ -19,6 +19,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
+#include "qemu/strList.h"
 #include "channel.h"
 #include "exec.h"
 #include "migration.h"
@@ -39,51 +40,16 @@ const char *exec_get_cmd_path(void)
 }
 #endif
 
-/* provides the length of strList */
-static int
-str_list_length(strList *list)
-{
-    int len = 0;
-    strList *elem;
-
-    for (elem = list; elem != NULL; elem = elem->next) {
-        len++;
-    }
-
-    return len;
-}
-
-static void
-init_exec_array(strList *command, char **argv, Error **errp)
-{
-    int i = 0;
-    strList *lst;
-
-    for (lst = command; lst; lst = lst->next) {
-        argv[i++] = lst->value;
-    }
-
-    argv[i] = NULL;
-    return;
-}
-
 void exec_start_outgoing_migration(MigrationState *s, strList *command,
                                    Error **errp)
 {
-    QIOChannel *ioc;
-
-    int length = str_list_length(command);
-    g_auto(GStrv) argv = (char **) g_new0(const char *, length + 1);
-
-    init_exec_array(command, argv, errp);
+    QIOChannel *ioc = NULL;
+    g_auto(GStrv) argv = strv_from_strList(command);
+    const char * const *args = (const char * const *) argv;
     g_autofree char *new_command = g_strjoinv(" ", (char **)argv);
 
     trace_migration_exec_outgoing(new_command);
-    ioc = QIO_CHANNEL(
-        qio_channel_command_new_spawn(
-                            (const char * const *) g_steal_pointer(&argv),
-                            O_RDWR,
-                            errp));
+    ioc = QIO_CHANNEL(qio_channel_command_new_spawn(args, O_RDWR, errp));
     if (!ioc) {
         return;
     }
@@ -105,19 +71,12 @@ static gboolean exec_accept_incoming_migration(QIOChannel *ioc,
 void exec_start_incoming_migration(strList *command, Error **errp)
 {
     QIOChannel *ioc;
-
-    int length = str_list_length(command);
-    g_auto(GStrv) argv = (char **) g_new0(const char *, length + 1);
-
-    init_exec_array(command, argv, errp);
+    g_auto(GStrv) argv = strv_from_strList(command);
+    const char * const *args = (const char * const *) argv;
     g_autofree char *new_command = g_strjoinv(" ", (char **)argv);
 
     trace_migration_exec_incoming(new_command);
-    ioc = QIO_CHANNEL(
-        qio_channel_command_new_spawn(
-                            (const char * const *) g_steal_pointer(&argv),
-                            O_RDWR,
-                            errp));
+    ioc = QIO_CHANNEL(qio_channel_command_new_spawn(args, O_RDWR, errp));
     if (!ioc) {
         return;
     }
-- 
2.41.0

Re: [PATCH v6 0/5] string list functions

[Steven Sistare]

Thanks for trying a V6 Philippe.  I'll take it from here.  It helps to know
that someone besides me thinks these functions are worth having.

- Steve

On 2/26/2024 9:11 AM, Philippe Mathieu-Daudé wrote:
> Hi Markus,
> 
> Here are the patches I queued until you told me you'd
> object to the CamelCase filename strList.[ch].
> 
> Steve, please take over ;)
> 
> Since v5:
> - Cover files in MAINTAINERS
> - Complete @docstring mentioning g_auto.
> 
> v5: https://lore.kernel.org/qemu-devel/1708638470-114846-3-git-send-email-steven.sistare@oracle.com/
> 
> Steve Sistare (5):
>   util: str_split
>   qapi: QAPI_LIST_LENGTH
>   util: strv_from_strList
>   util: strList unit tests
>   migration: simplify exec migration functions
> 
>  MAINTAINERS               |  2 +
>  include/monitor/hmp.h     |  1 -
>  include/qapi/util.h       | 13 +++++++
>  include/qemu/strList.h    | 33 ++++++++++++++++
>  migration/exec.c          | 57 ++++------------------------
>  monitor/hmp-cmds.c        | 19 ----------
>  net/net-hmp-cmds.c        |  3 +-
>  stats/stats-hmp-cmds.c    |  3 +-
>  tests/unit/test-strList.c | 80 +++++++++++++++++++++++++++++++++++++++
>  util/strList.c            | 38 +++++++++++++++++++
>  tests/unit/meson.build    |  1 +
>  util/meson.build          |  1 +
>  12 files changed, 180 insertions(+), 71 deletions(-)
>  create mode 100644 include/qemu/strList.h
>  create mode 100644 tests/unit/test-strList.c
>  create mode 100644 util/strList.c
> 

Re: [PATCH v6 0/5] string list functions

[Markus Armbruster]

Philippe Mathieu-Daudé <philmd@linaro.org> writes:

> Hi Markus,
>
> Here are the patches I queued until you told me you'd
> object to the CamelCase filename strList.[ch].
>
> Steve, please take over ;)

I'm going to post the part of the series I'm ready to queue as v7, with
minor modifications:

* Rename strv_from_strList() to strv_from_str_list(), and put it into
  qapi/qapi-type-helpers.c.

* Tweak its function comment.

* Rename its local variable @argv to @strv.

* Cosmetic commit message tweaks.

We can then talk about the remainder.

Re: [PATCH v6 0/5] string list functions

[Steven Sistare]

On 2/27/2024 10:28 AM, Markus Armbruster wrote:
> Philippe Mathieu-Daudé <philmd@linaro.org> writes:
> 
>> Hi Markus,
>>
>> Here are the patches I queued until you told me you'd
>> object to the CamelCase filename strList.[ch].
>>
>> Steve, please take over ;)
> 
> I'm going to post the part of the series I'm ready to queue as v7, with
> minor modifications:
> 
> * Rename strv_from_strList() to strv_from_str_list(), and put it into
>   qapi/qapi-type-helpers.c.
> 
> * Tweak its function comment.
> 
> * Rename its local variable @argv to @strv.
> 
> * Cosmetic commit message tweaks.
> 
> We can then talk about the remainder.

Thanks Markus, that saves some time and email.

- Steve