[U-Boot] [PATCH v3 3/6] Introduce CONFIG_BUG_CHECKS to allow to disable BUG{_ON} and WARN_ON

[Masahiro Yamada]

BUG(), BUG_ON(), WARN_ON(), etc. are generally used to test a condition
that should never happen.  If it does, it is a bug, then they print
noisy messages.

They are useful to catch bugs, and Linux always enables them, but doing
so in U-Boot causes image size problems on some platforms.

Introduce CONFIG_BUG_CHECKS to switch this feature.  It is enabled by
default since it is the current behavior.  Disable it if your platform
needs to save memory footprint.

Suggested-by: Tom Rini <trini at konsulko.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
---

Changes in v3:
  - Flip the default to 'y'
  - Rename CONFIG_ENABLE_BUG_CHECKS to CONFIG_BUG_CHECKS
    because I thought "ENABLE" was not a necessary word
  - define to "do {} while (0)"

Changes in v2:
  - Newly added

 include/linux/bug.h | 9 ++++++++-
 lib/Kconfig         | 9 +++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/include/linux/bug.h b/include/linux/bug.h
index f07bb71..045e639 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -6,17 +6,24 @@
 #include <linux/compiler.h>
 #include <linux/printk.h>
 
+#ifdef CONFIG_BUG_CHECKS
 #define BUG() do { \
 	printk("BUG at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
 	panic("BUG!"); \
 } while (0)
+#define __WARN()	\
+	printk("WARNING at %s:%d/%s()!\n", __FILE__, __LINE__, __func__)
+#else
+#define BUG()		do {} while (0)
+#define __WARN()	do {} while (0)
+#endif
 
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
 
 #define WARN_ON(condition) ({						\
 	int __ret_warn_on = !!(condition);				\
 	if (unlikely(__ret_warn_on))					\
-		printk("WARNING at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
+		__WARN();						\
 	unlikely(__ret_warn_on);					\
 })
 
diff --git a/lib/Kconfig b/lib/Kconfig
index 00ac650..dee5dc2 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -45,6 +45,15 @@ config USE_TINY_PRINTF
 
 	  The supported format specifiers are %c, %s, %u/%d and %x.
 
+config BUG_CHECKS
+	bool "Enable BUG/BUG_ON() checks and WARN_ON() logs"
+	default y
+	help
+	  BUG(), BUG_ON(), and WARN_ON() print noisy messages.  BUG() and
+	  BUG_ON() also reboot or halt the system.
+
+	  Disable this if your platform needs to save memory footprint.
+
 config PANIC_HANG
 	bool "Do not reset the system on fatal error"
 	help
-- 
2.7.4