Fix some clang warnings

the issue in cmd_debug - passing members of struct bpos to kstrtoull,
which aren't aligned - was a legit bug

Makefile

@@ -2,7 +2,6 @@
 PREFIX=/usr
 INSTALL=install
 CFLAGS+=-std=gnu99 -O2 -g -MMD -Wall				\
-	-Wno-unused-but-set-variable				\
 	-Wno-pointer-sign					\
 	-fno-strict-aliasing					\
 	-I. -Iinclude -Ilibbcachefs				\
@@ -16,12 +15,23 @@ CFLAGS+=-std=gnu99 -O2 -g -MMD -Wall				\
 	$(EXTRA_CFLAGS)
 LDFLAGS+=-O2 -g
 
-ifdef D
-	CFLAGS+=-Werror
-else
+CC_VERSION=$(shell $(CC) -v 2>&1|grep -E '(gcc|clang) version')
+
+ifneq (,$(findstring gcc,$(CC_VERSION)))
+	CFLAGS+=-Wno-unused-but-set-variable
+ifndef D
 	CFLAGS+=-flto
 	LDFLAGS+=-flto
 endif
+endif
+
+ifneq (,$(findstring clang,$(CC_VERSION)))
+	CFLAGS+=-Wno-missing-braces
+endif
+
+ifdef D
+	CFLAGS+=-Werror
+endif
 
 PKGCONFIG_LIBS="blkid uuid liburcu libsodium zlib"
 CFLAGS+=`pkg-config --cflags	${PKGCONFIG_LIBS}`

cmd_debug.c

@@ -192,14 +192,14 @@ static struct bpos parse_pos(char *buf)
 	char *s = buf;
 	char *inode	= strsep(&s, ":");
 	char *offset	= strsep(&s, ":");
-	struct bpos ret = { 0 };
+	u64 inode_v, offset_v;
 
 	if (!inode || !offset || s ||
-	    kstrtoull(inode, 10, &ret.inode) ||
-	    kstrtoull(offset, 10, &ret.offset))
+	    kstrtoull(inode, 10, &inode_v) ||
+	    kstrtoull(offset, 10, &offset_v))
 		die("invalid bpos %s", buf);
 
-	return ret;
+	return (struct bpos) { .inode = inode_v, .offset = offset_v };
 }
 
 static void list_keys_usage(void)

cmd_fs.c

@@ -23,9 +23,10 @@ int cmd_fs_show(int argc, char *argv[])
 	if (argc != 2)
 		die("Please supply a filesystem");
 
+#if 0
 	struct bcache_handle fs = bcache_fs_open(argv[1]);
+#endif
 
-	fs = fs;
 	return 0;
 }
 
@@ -34,8 +35,9 @@ int cmd_fs_set(int argc, char *argv[])
 	if (argc != 2)
 		die("Please supply a filesystem");
 
+#if 0
 	struct bcache_handle fs = bcache_fs_open(argv[1]);
+#endif
 
-	fs = fs;
 	return 0;
 }

include/linux/blkdev.h

@@ -4,8 +4,8 @@
 #include <linux/backing-dev.h>
 #include <linux/blk_types.h>
 #include <linux/kobject.h>
+#include <linux/types.h>
 
-typedef u64 sector_t;
 typedef unsigned fmode_t;
 
 struct bio;

include/linux/bug.h

@@ -22,10 +22,10 @@
 #define WARN(cond, ...)		assert(!(cond))
 
 #define WARN_ON(condition) ({						\
-	int __ret_warn_on = !!(condition);				\
-	if (unlikely(__ret_warn_on))					\
+	int __ret_warn_on = unlikely(!!(condition));			\
+	if (__ret_warn_on)						\
 		__WARN();						\
-	unlikely(__ret_warn_on);					\
+	__ret_warn_on;							\
 })
 
 #endif /* __TOOLS_LINUX_BUG_H */

include/linux/spinlock.h

@@ -30,7 +30,7 @@ static inline void raw_spin_unlock(raw_spinlock_t *lock)
 
 #define raw_spin_lock_irqsave(lock, flags)		\
 do {							\
-	(void) flags;					\
+	flags = 0;					\
 	raw_spin_lock(lock);				\
 } while (0)