From c50c5ea436adba4b3c6cd1b1d9017adc9f16926d Mon Sep 17 00:00:00 2001
From: Marian Buschsieweke <marian.buschsieweke@ovgu.de>
Date: Fri, 12 Nov 2021 15:55:33 +0100
Subject: [PATCH] pkg/spifs: silence -Wcast-align

---
 pkg/spiffs/Makefile       |  2 ++
 pkg/spiffs/fs/spiffs_fs.c | 13 ++++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/pkg/spiffs/Makefile b/pkg/spiffs/Makefile
index 8ab66b4bff..36b1893c7f 100644
--- a/pkg/spiffs/Makefile
+++ b/pkg/spiffs/Makefile
@@ -8,5 +8,7 @@ include $(RIOTBASE)/pkg/pkg.mk
 # Disable 'ISO C99 doesn’t support unnamed structs/unions [-Werror=pedantic]'
 CFLAGS += -Wno-pedantic
 
+CFLAGS += -Wno-cast-align
+
 all:
 	$(QQ)"$(MAKE)" -C $(PKG_SOURCE_DIR)/src -f $(RIOTBASE)/Makefile.base MODULE=$(PKG_NAME)
diff --git a/pkg/spiffs/fs/spiffs_fs.c b/pkg/spiffs/fs/spiffs_fs.c
index f9d3d60bdf..055b93f6ea 100644
--- a/pkg/spiffs/fs/spiffs_fs.c
+++ b/pkg/spiffs/fs/spiffs_fs.c
@@ -355,10 +355,17 @@ static int _fstat(vfs_file_t *filp, struct stat *buf)
     return spiffs_err_to_errno(ret);
 }
 
+static spiffs_DIR * _get_spifs_dir(vfs_DIR *dirp)
+{
+    /* the private buffer is part of a union that also contains a
+     * void pointer, hence, it is naturally aligned */
+    return (spiffs_DIR *)(uintptr_t)&dirp->private_data.buffer[0];
+}
+
 static int _opendir(vfs_DIR *dirp, const char *dirname, const char *abs_path)
 {
     spiffs_desc_t *fs_desc = dirp->mp->private_data;
-    spiffs_DIR *d = (spiffs_DIR *)&dirp->private_data.buffer[0];
+    spiffs_DIR *d = _get_spifs_dir(dirp);
     (void) abs_path;
 
     spiffs_DIR *res = SPIFFS_opendir(&fs_desc->fs, dirname, d);
@@ -371,7 +378,7 @@ static int _opendir(vfs_DIR *dirp, const char *dirname, const char *abs_path)
 
 static int _readdir(vfs_DIR *dirp, vfs_dirent_t *entry)
 {
-    spiffs_DIR *d = (spiffs_DIR *)&dirp->private_data.buffer[0];
+    spiffs_DIR *d = _get_spifs_dir(dirp);
     struct spiffs_dirent e;
     struct spiffs_dirent *ret;
 
@@ -396,7 +403,7 @@ static int _readdir(vfs_DIR *dirp, vfs_dirent_t *entry)
 
 static int _closedir(vfs_DIR *dirp)
 {
-    spiffs_DIR *d = (spiffs_DIR *)&dirp->private_data.buffer[0];
+    spiffs_DIR *d = _get_spifs_dir(dirp);
 
     return spiffs_err_to_errno(SPIFFS_closedir(d));
 }