From 490b06e24bbfa4cd4cdbeaa82ef15ed48694841e Mon Sep 17 00:00:00 2001
From: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Date: Tue, 25 Jun 2019 12:17:58 +0200
Subject: [PATCH] queue: redefine TAILQ_REMOVE for scan-build

scan-build can't follow double pointers in tailqs and
often assumes that removed elements are still on the
list, so now if we detect __clang_analyzer__ we'll
redefine TAILQ_REMOVE with extra asserts to silence
those scan-build errors.

Change-Id: I14134d8e75f7829e178b74d19f711f77cf018f14
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/459285
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: yidong0635 <dongx.yi@intel.com>
---
 include/spdk/queue.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/include/spdk/queue.h b/include/spdk/queue.h
index a24dd0070..24e2e2e20 100644
--- a/include/spdk/queue.h
+++ b/include/spdk/queue.h
@@ -50,6 +50,28 @@ extern "C" {
 #include "spdk/queue_extras.h"
 #endif
 
+/*
+ * scan-build can't follow double pointers in queues and often assumes
+ * that removed elements are still on the list. We redefine TAILQ_REMOVE
+ * with extra asserts to silence it.
+ */
+#ifdef __clang_analyzer__
+#undef TAILQ_REMOVE
+#define TAILQ_REMOVE(head, elm, field) do {				\
+	__typeof__(elm) _elm;						\
+	if (((elm)->field.tqe_next) != NULL)				\
+		(elm)->field.tqe_next->field.tqe_prev =			\
+		    (elm)->field.tqe_prev;				\
+	else								\
+		(head)->tqh_last = (elm)->field.tqe_prev;		\
+	*(elm)->field.tqe_prev = (elm)->field.tqe_next;			\
+	/* make sure the removed elm is not on the list anymore */	\
+	TAILQ_FOREACH(_elm, head, field) {				\
+		assert(_elm != elm);					\
+	}								\
+} while (0)
+#endif
+
 #ifdef __cplusplus
 }
 #endif