[libvirt] [PATCH 1/3] util: error: Add helpers for saving and restoring of last error
Some cleanup paths overwrite a usefull error message with a less useful
one and we then try to preserve the original message. The handlers added
in this patch will simplify the operations since they are designed right
for the purpose.
---
src/libvirt_private.syms | 2 ++
src/util/virerror.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
src/util/virerror.h | 3 +++
3 files changed, 50 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index f30a04b14..62e05186d 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1604,6 +1604,8 @@ ebtablesRemoveForwardAllowIn;
virDispatchError;
virErrorCopyNew;
virErrorInitialize;
+virErrorPreserveLast;
+virErrorRestore;
virErrorSetErrnoFromLastError;
virLastErrorIsSystemErrno;
virRaiseErrorFull;
diff --git a/src/util/virerror.c b/src/util/virerror.c
index a5a2d6ed1..1f15c5dbb 100644
--- a/src/util/virerror.c
+++ b/src/util/virerror.c
@@ -371,6 +371,51 @@ virSaveLastError(void)
return to;
}
+
+/**
+ * virErrorPreserveLast:
+ * @saveerr: pointer to virErrorPtr for storing last error object
+ *
+ * Preserves the currently set last error (for the thread) into @saveerr so that
+ * it can be restored via virErrorRestore(). @saveerr must be passed to
+ * virErrorRestore()
+ */
+void
+virErrorPreserveLast(virErrorPtr *saveerr)
+{
+ int saved_errno = errno;
+ virErrorPtr lasterr = virGetLastError();
+
+ *saveerr = NULL;
+
+ if (lasterr)
+ *saveerr = virErrorCopyNew(lasterr);
+
+ errno = saved_errno;
+}
+
+
+/**
+ * virErrorRestore:
+ * @savederr: error object holding saved error
+ *
+ * Restores the error passed via @savederr and clears associated memory.
+ */
+void
+virErrorRestore(virErrorPtr *savederr)
+{
+ int saved_errno = errno;
+
+ if (!*savederr)
+ return;
+
+ virSetError(*savederr);
+ virFreeError(*savederr);
+ *savederr = NULL;
+ errno = saved_errno;
+}
+
+
/**
* virResetError:
* @err: pointer to the virError to clean up
diff --git a/src/util/virerror.h b/src/util/virerror.h
index 234864812..54530d081 100644
--- a/src/util/virerror.h
+++ b/src/util/virerror.h
@@ -196,4 +196,7 @@ void virErrorSetErrnoFromLastError(void);
bool virLastErrorIsSystemErrno(int errnum);
+void virErrorPreserveLast(virErrorPtr *saveerr);
+void virErrorRestore(virErrorPtr *savederr);
+
#endif
--
2.14.1