Re: [Qemu-ppc] [Qemu-devel] [PATCH v2 00/15] Debug output revamp

[Peter Crosthwaite]

Hi All,

On Sat, Feb 23, 2013 at 3:41 AM, Andreas Färber <address@hidden> wrote:
> Am 22.02.2013 17:54, schrieb Richard Henderson:
>> On 02/22/2013 08:16 AM, Andreas Färber wrote:
>>> I would be willing to do a macro-based v3 using do { ... } while (0) if
>>> maintainers can reach agreement on that and on how to do the if (0).
>>
>> FWIW, I'm in favor of the
>>
>> #ifndef DEBUG
>> # define DEBUG 0
>> #endif
>> #define MACRO_NAME(...) \
>>   do { if (DEBUG) { log(...) } } while (0)
>>

+1. I already have a series on list (Zynq I2C) doing exactly this on 3
new device models:

http://comments.gmane.org/gmane.comp.emulators.qemu/195651

Example below:

+
+#ifndef PCA9548_DEBUG
+#define PCA9548_DEBUG 0
+#endif
+#define DB_PRINT(fmt, args...) do {\
+    if (PCA9548_DEBUG) {\
+        fprintf(stderr, "PCA9548: "fmt, ## args);\
+    } \
+} while (0);
+

Regards,
Peter

>> sort of solution.  Immediate constant into the IF, which even an -O0
>> compile will delete as dead.
>
> I remember there being complaints about me changing in-code #ifdefs to
> #ifs in v1 as a consequence... some naming convention like #ifdef DEBUG
> #define DEBUG_ON 1 #else #define DEBUG_ON 0 or so would address that.
> Let's wait for some more feedback.
>
> Andreas
>
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