Re: linux-next: driver-core tree build failure

Geert Uytterhoeven
2009-03-10T15:30:07Z

On Tue, 10 Mar 2009, Martin Schwidefsky wrote:
> On Tue, 10 Mar 2009 14:31:17 +0100 (CET)
> Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> wrote:
>
> > crypto/zlib.c has:
> >
> > #define pr_fmt(fmt) "%s: " fmt, __func__
> >
> > If CONFIG_DYNAMIC_DEBUG is set, include/linux/kernel.h has:
> >
> > #define pr_debug(fmt, ...) do { \
> > dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
> > } while (0)
> >
> > include/linux/dynamic_debug.h has:
> >
> > #define dynamic_pr_debug(fmt, ...) do { \
> > static struct _ddebug descriptor \
> > __used \
> > __attribute__((section("__verbose"), aligned(8))) = \
> > { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \
> > DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \
> > if (__dynamic_dbg_enabled(descriptor)) \
> > printk(KERN_DEBUG KBUILD_MODNAME ":" fmt, \
> > ##__VA_ARGS__); \
> > } while (0)
>
> The dynamic_pr_debug macro currently works only with pr_fmt definitions
> that do not add additional parameters. The way how we use the pr_fmt
> macro is:
>
> #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
>
> The same could be done with the problematic pr_fmt definition:
>
> #define pr_fmt(fmt) __func__ ": " fmt

No, that also doesn't work:

| crypto/zlib.c:150: error: expected '}' before string constant
| crypto/zlib.c:150: error: expected ')' before '__func__'
| crypto/zlib.c:162: error: expected '}' before string constant
| crypto/zlib.c:162: error: expected ')' before '__func__'
| crypto/zlib.c:166: error: expected '}' before string constant
| crypto/zlib.c:166: error: expected ')' before '__func__'
| crypto/zlib.c:170: error: expected '}' before string constant
| crypto/zlib.c:170: error: expected ')' before '__func__'

> > BTW, Martin: Is `#define pr_fmt(fmt) "%s: " fmt, __func__' a valid and
> > intended usage of your pr_fmt() infrastructure?
>
> The indended use is a simple prefix to the format string. To paste an
> additional parameter is an interesting use of the pr_fmt macro ..

Bummer, I was so happy I could do things like

| #define pr_fmt(fmt) "%s:%u: " fmt, __func__, __LINE__

...

With kind regards,

Geert Uytterhoeven
Software Architect

Sony Techsoft Centre Europe
The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium

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