From 76614d52006ae484a78076ee94635c9d669e528a Mon Sep 17 00:00:00 2001
From: Kinsey Moore <nyphbl8d@gmail.com>
Date: Thu, 29 Jan 2026 14:14:49 -0600
Subject: [PATCH] jffs2: Resolve signed comparison warnings

JFFS2 uses the high values of the unsigned flash offset in a raw node
reference as special identifiers and specifies them using negative
integer literals. This disables those errors for non-RTEMS source and
constrains such comparisons in RTEMS code to avoid larger reworks of the
JFFS2 upstream source.
---
 contrib/cpukit/jffs2/nodelist.h           | 22 ++++++++++++++++++++++
 cpukit/libfs/src/jffs2/src/malloc-rtems.c |  6 +++---
 spec/build/cpukit/objjffs2contrib.yml     |  1 +
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/contrib/cpukit/jffs2/nodelist.h b/contrib/cpukit/jffs2/nodelist.h
index b30aa5bbf6..2f7f9b395e 100644
--- a/contrib/cpukit/jffs2/nodelist.h
+++ b/contrib/cpukit/jffs2/nodelist.h
@@ -98,6 +98,25 @@ struct jffs2_raw_node_ref
 /* Use blocks of about 256 bytes */
 #define REFS_PER_BLOCK ((255/sizeof(struct jffs2_raw_node_ref))-1)
 
+#ifdef __rtems__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wsign-compare"
+/*
+ * The REF_LINK_NODE and REF_EMPTY_NODE macros should really be uint32_t bit
+ * patterns instead of signed integer literals to avoid signed comparison
+ * warnings. This contains all comparisons using them to this section where
+ * signed comparison warnings are disabled.
+ */
+static inline bool rtems_jffs2_is_ref_link(struct jffs2_raw_node_ref *ref)
+{
+  return ref->flash_offset == REF_LINK_NODE;
+}
+
+static inline bool rtems_jffs2_is_ref_empty(struct jffs2_raw_node_ref *ref)
+{
+  return ref->flash_offset == REF_EMPTY_NODE;
+}
+#endif
 static inline struct jffs2_raw_node_ref *ref_next(struct jffs2_raw_node_ref *ref)
 {
 	ref++;
@@ -115,6 +134,9 @@ static inline struct jffs2_raw_node_ref *ref_next(struct jffs2_raw_node_ref *ref
 
 	return ref;
 }
+#ifdef __rtems__
+#pragma GCC diagnostic pop
+#endif
 
 static inline struct jffs2_inode_cache *jffs2_raw_ref_to_ic(struct jffs2_raw_node_ref *raw)
 {
diff --git a/cpukit/libfs/src/jffs2/src/malloc-rtems.c b/cpukit/libfs/src/jffs2/src/malloc-rtems.c
index 81c3cec2ae..3201f762cd 100644
--- a/cpukit/libfs/src/jffs2/src/malloc-rtems.c
+++ b/cpukit/libfs/src/jffs2/src/malloc-rtems.c
@@ -72,7 +72,7 @@ static struct jffs2_raw_node_ref *jffs2_alloc_refblock(void)
 
 	ret = malloc((REFS_PER_BLOCK + 1) * sizeof(*ret));
 	if (ret) {
-		int i = 0;
+		uint32_t i = 0;
 		for (i=0; i < REFS_PER_BLOCK; i++) {
 			ret[i].flash_offset = REF_EMPTY_NODE;
 			ret[i].next_in_ino = NULL;
@@ -95,7 +95,7 @@ int jffs2_prealloc_raw_node_refs(struct jffs2_sb_info *c,
 	ref = *p;
 
 	/* If jeb->last_node is really a valid node then skip over it */
-	if (ref && ref->flash_offset != REF_EMPTY_NODE)
+	if (ref && !rtems_jffs2_is_ref_empty(ref))
 		ref++;
 
 	while (i) {
@@ -104,7 +104,7 @@ int jffs2_prealloc_raw_node_refs(struct jffs2_sb_info *c,
 			if (!ref)
 				return -ENOMEM;
 		}
-		if (ref->flash_offset == REF_LINK_NODE) {
+		if (rtems_jffs2_is_ref_link(ref)) {
 			p = &ref->next_in_ino;
 			ref = *p;
 			continue;
diff --git a/spec/build/cpukit/objjffs2contrib.yml b/spec/build/cpukit/objjffs2contrib.yml
index f730e80d10..b9bab1922b 100644
--- a/spec/build/cpukit/objjffs2contrib.yml
+++ b/spec/build/cpukit/objjffs2contrib.yml
@@ -3,6 +3,7 @@ build-type: objects
 cflags:
 - ${COVERAGE_COMPILER_FLAGS}
 - -Wno-pointer-sign
+- -Wno-sign-compare
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH & Co. KG
 cppflags: []