From 62e22785c706e7ee7f99a6600d4505dc890838ef Mon Sep 17 00:00:00 2001
Message-Id: <62e22785c706e7ee7f99a6600d4505dc890838ef@dist-git>
From: Peter Krempa <pkrempa@redhat.com>
Date: Fri, 19 Jun 2020 11:43:11 +0200
Subject: [PATCH] util: string: Introduce macro for automatic string lists
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Similar to VIR_AUTOPTR, VIR_AUTOSTRINGLIST defines a list of strings
which will be freed if the pointer is leaving scope.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
(cherry picked from commit daefda165b28b399478137c75b5466f865c65be5)

https://bugzilla.redhat.com/show_bug.cgi?id=1839992

Conflicts:
- src/util/virstring.h - Context. This is RHEL-7.9; did you
  really think this would be a clean backport? Plenty of
  patches changed virstring.h in the last two years.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Message-Id: <c78797a8247bcfb5893bf7b1c2570e98ccda0dd1.1592559697.git.mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/util/virstring.c     | 10 ++++++++++
 src/util/virstring.h     | 10 ++++++++++
 3 files changed, 21 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 2a3950fd35..3e5448af94 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2917,6 +2917,7 @@ virStringHasControlChars;
 virStringIsEmpty;
 virStringIsPrintable;
 virStringListAdd;
+virStringListAutoFree;
 virStringListFree;
 virStringListFreeCount;
 virStringListGetFirstWithPrefix;
diff --git a/src/util/virstring.c b/src/util/virstring.c
index 15f367af7c..0f13b6c664 100644
--- a/src/util/virstring.c
+++ b/src/util/virstring.c
@@ -332,6 +332,16 @@ void virStringListFree(char **strings)
 }
 
 
+void virStringListAutoFree(char ***strings)
+{
+    if (!*strings)
+        return;
+
+    virStringListFree(*strings);
+    *strings = NULL;
+}
+
+
 /**
  * virStringListFreeCount:
  * @strings: array of strings to free
diff --git a/src/util/virstring.h b/src/util/virstring.h
index 607ae66e99..e68b9eec79 100644
--- a/src/util/virstring.h
+++ b/src/util/virstring.h
@@ -53,6 +53,7 @@ int virStringListCopy(char ***dst,
                       const char **src);
 
 void virStringListFree(char **strings);
+void virStringListAutoFree(char ***strings);
 void virStringListFreeCount(char **strings,
                             size_t count);
 
@@ -309,4 +310,13 @@ int virStringParsePort(const char *str,
                        unsigned int *port)
     ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
 
+/**
+ * VIR_AUTOSTRINGLIST:
+ *
+ * Declares a NULL-terminated list of strings which will be automatically freed
+ * when the pointer goes out of scope.
+ */
+# define VIR_AUTOSTRINGLIST \
+        __attribute__((cleanup(virStringListAutoFree))) char **
+
 #endif /* __VIR_STRING_H__ */
-- 
2.27.0