Patchwork [U-Boot,v2] Add assert() for debug assertions

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Submitter Simon Glass
Date June 23, 2011, 11:14 p.m.
Message ID <1308870873-32540-1-git-send-email-sjg@chromium.org>
Download mbox | patch
Permalink /patch/101702/
State New, archived
Headers show

Comments

Simon Glass - June 23, 2011, 11:14 p.m.
assert() is like BUG_ON() but compiles to nothing unless DEBUG is defined.
This is useful when a condition is an error but a board reset is unlikely
to fix it, so it is better to soldier on in hope. Assertion failures should
be caught during development/test.

It turns out that assert() is defined separately in a few places in U-Boot
with various meanings. This patch cleans up some of these.

Build errors exposed by this change (and defining DEBUG) are also fixed in
this patch.

Signed-off-by: Simon Glass <sjg@chromium.org>
---
V2:
* Changed macros so that all code is compiled even if DEBUG is disabled
---
 common/dlmalloc.c |    7 -------
 include/common.h  |   19 +++++++++++++++++++
 include/malloc.h  |    8 --------
 lib/qsort.c       |    5 -----
 4 files changed, 19 insertions(+), 20 deletions(-)
Mike Frysinger - June 23, 2011, 11:40 p.m.
Acked-by: Mike Frysinger <vapier@gentoo.org>
-mike
Wolfgang Denk - June 24, 2011, 5:33 a.m.
Dear Simon Glass,

In message <1308870873-32540-1-git-send-email-sjg@chromium.org> you wrote:
> assert() is like BUG_ON() but compiles to nothing unless DEBUG is defined.
> This is useful when a condition is an error but a board reset is unlikely
> to fix it, so it is better to soldier on in hope. Assertion failures should
> be caught during development/test.
> 
> It turns out that assert() is defined separately in a few places in U-Boot
> with various meanings. This patch cleans up some of these.
> 
> Build errors exposed by this change (and defining DEBUG) are also fixed in
> this patch.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
> V2:
> * Changed macros so that all code is compiled even if DEBUG is disabled
...
> +#define assert(x)	\
> +	({ if (!(x) && _DEBUG) \
> +		printf("Assertion failure '%s' %s line %d\n", \
> +			#x, __FILE__, __LINE__); })

Can we please use the same message format as used by assert(3) ?
Afaict they use "%s%s%s:%u: %s%sAssertion `%s' failed.".

Also, to save on memory footprint (frequent repetition of the common
string "Assertion failed") we should probably provide a separate
function for this (cf. /usr/include/assert.h).

Finally, should the assert() not result in some termination or hang of
U-Boot, like assert(3) is doing?

Best regards,

Wolfgang Denk
Simon Glass - June 24, 2011, 6:13 p.m.
Hi Wolfgang,

On Thu, Jun 23, 2011 at 10:33 PM, Wolfgang Denk <wd@denx.de> wrote:
> Dear Simon Glass,
...
>> +#define assert(x)    \
>> +     ({ if (!(x) && _DEBUG) \
>> +             printf("Assertion failure '%s' %s line %d\n", \
>> +                     #x, __FILE__, __LINE__); })
>
> Can we please use the same message format as used by assert(3) ?
> Afaict they use "%s%s%s:%u: %s%sAssertion `%s' failed.".

Yes, will do.

>
> Also, to save on memory footprint (frequent repetition of the common
> string "Assertion failed") we should probably provide a separate
> function for this (cf. /usr/include/assert.h).

Good idea will do.

>
> Finally, should the assert() not result in some termination or hang of
> U-Boot, like assert(3) is doing?

I'm happy either way so long as it prints a message. A hang is better
than a reboot for those with ICE units, etc. My intention was that it
would simply print the message and try to continue (since we can't
really 'terminate' U-Boot, and it continues with DEBUG not defined).

But I am happy either way, so let me know if you would like it to hang.

Regards,
Simon

>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
> "What the scientists have in their briefcases is terrifying."
> - Nikita Khrushchev
>
Mike Frysinger - June 24, 2011, 6:15 p.m.
On Fri, Jun 24, 2011 at 14:13, Simon Glass wrote:
> On Thu, Jun 23, 2011 at 10:33 PM, Wolfgang Denk wrote:
>> Finally, should the assert() not result in some termination or hang of
>> U-Boot, like assert(3) is doing?
>
> I'm happy either way so long as it prints a message. A hang is better
> than a reboot for those with ICE units, etc. My intention was that it
> would simply print the message and try to continue (since we can't
> really 'terminate' U-Boot, and it continues with DEBUG not defined).

use panic() instead of printf() and then the hang-vs-reset issue is
made into a board-config issue (CONFIG_PANIC_HANG)
-mike

Patch

diff --git a/common/dlmalloc.c b/common/dlmalloc.c
index e9bab09..f2080c6 100644
--- a/common/dlmalloc.c
+++ b/common/dlmalloc.c
@@ -286,13 +286,6 @@  extern "C" {
 
 */
 
-#ifdef DEBUG
-#include <assert.h>
-#else
-#define assert(x) ((void)0)
-#endif
-
-
 /*
   INTERNAL_SIZE_T is the word-size used for internal bookkeeping
   of chunk sizes. On a 64-bit machine, you can reduce malloc
diff --git a/include/common.h b/include/common.h
index 1e21b7a..6181e07 100644
--- a/include/common.h
+++ b/include/common.h
@@ -124,6 +124,25 @@  typedef volatile unsigned char	vu_char;
 #define debugX(level,fmt,args...)
 #endif	/* DEBUG */
 
+#ifdef DEBUG
+# define _DEBUG 1
+#else
+# define _DEBUG 0
+#endif
+
+/*
+ * An assertion is run-time check done in debug mode only. If DEBUG is not
+ * defined then it is skipped. It does not BUG or halt U-Boot, but tries to
+ * continue execution in any case. It is hoped that all failing assertions
+ * are found before release, and after release it is hoped that they don't
+ * matter. But in any case these failing assertions cannot be fixed with a
+ * BUG-type reset (which may just do the same assertion again).
+ */
+#define assert(x)	\
+	({ if (!(x) && _DEBUG) \
+		printf("Assertion failure '%s' %s line %d\n", \
+			#x, __FILE__, __LINE__); })
+
 #define error(fmt, args...) do {					\
 		printf("ERROR: " fmt "\nat %s:%d/%s()\n",		\
 			##args, __FILE__, __LINE__, __func__);		\
diff --git a/include/malloc.h b/include/malloc.h
index 3e145ad..ecf3c67 100644
--- a/include/malloc.h
+++ b/include/malloc.h
@@ -285,14 +285,6 @@  extern "C" {
 
 */
 
-#ifdef DEBUG
-/* #include <assert.h> */
-#define assert(x) ((void)0)
-#else
-#define assert(x) ((void)0)
-#endif
-
-
 /*
   INTERNAL_SIZE_T is the word-size used for internal bookkeeping
   of chunk sizes. On a 64-bit machine, you can reduce malloc
diff --git a/lib/qsort.c b/lib/qsort.c
index 1cc0d31..86c392c 100644
--- a/lib/qsort.c
+++ b/lib/qsort.c
@@ -17,11 +17,6 @@ 
 
 #include <linux/types.h>
 #include <exports.h>
-#if 0
-#include <assert.h>
-#else
-#define assert(arg)
-#endif
 
 void qsort(void  *base,
 	   size_t nel,