[PATCH v3 1/7] vsprintf: factorize "(null)" string

[PATCH v3 1/7] vsprintf: factorize "(null)" string

[André Goddard Rosa]

From: André Goddard Rosa <andre.goddard@gmail.com>
Date: Tue, 3 Nov 2009 11:07:21 -0200
Subject: [PATCH v3 1/7] vsprintf: factorize "(null)" string
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Change "<NULL>" to "(null)" and make it a static const char[] hoping that
the compiler will make null_str a label to a read-only area containing it.

See:
http://people.redhat.com/drepper/dsohowto.pdf part 2.4.2
http://udrepper.livejournal.com/13851.html
http://udrepper.livejournal.com/15119.html

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
---
 lib/vsprintf.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 33bed5e..002f462 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -34,6 +34,8 @@
 /* Works only for digits and letters, but small and fast */
 #define TOLOWER(x) ((x) | 0x20)

+static const char null_str[] = "(null)";
+
 static unsigned int simple_guess_base(const char *cp)
 {
 	if (cp[0] == '0') {
@@ -546,12 +548,12 @@ static char *number(char *buf, char *end,
unsigned long long num,
 	return buf;
 }

-static char *string(char *buf, char *end, char *s, struct printf_spec spec)
+static char *string(char *buf, char *end, const char *s, struct
printf_spec spec)
 {
 	int len, i;

 	if ((unsigned long)s < PAGE_SIZE)
-		s = "<NULL>";
+		s = null_str;

 	len = strnlen(s, spec.precision);

@@ -822,7 +824,7 @@ static char *pointer(const char *fmt, char *buf,
char *end, void *ptr,
 			struct printf_spec spec)
 {
 	if (!ptr)
-		return string(buf, end, "(null)", spec);
+		return string(buf, end, null_str, spec);

 	switch (*fmt) {
 	case 'F':
@@ -1445,7 +1447,7 @@ do {									\
 			size_t len;
 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
 					|| (unsigned long)save_str < PAGE_SIZE)
-				save_str = "<NULL>";
+				save_str = null_str;
 			len = strlen(save_str);
 			if (str + len + 1 < end)
 				memcpy(str, save_str, len + 1);
-- 
1.6.5.2.143.g8cc62.dirty

Re: [PATCH v3 1/7] vsprintf: factorize "(null)" string

[Ingo Molnar]

* Andr? Goddard Rosa <andre.goddard@gmail.com> wrote:

> @@ -546,12 +548,12 @@ static char *number(char *buf, char *end,
> unsigned long long num,
>  	return buf;
>  }
> 
> -static char *string(char *buf, char *end, char *s, struct printf_spec spec)
> +static char *string(char *buf, char *end, const char *s, struct
> printf_spec spec)

FYI, your patches have such linewraps, so the patches wont apply:

 patch: **** malformed patch at line 47: unsigned long long num,

See Documentation/email-clients.txt about how to send patches without 
such problems.

Mind resending with this fixed?

Also, this RFC patch of yours:

  vsprintf: reuse almost identical simple_strtoulX() functions

looks nice too IMO - mind including it in your series?

Thanks,

	Ingo

Re: [PATCH v3 1/7] vsprintf: factorize "(null)" string

[André Goddard Rosa]

Hi, Ingo!

On Sun, Nov 8, 2009 at 9:02 AM, Ingo Molnar <mingo@elte.hu> wrote:
>
> * Andr? Goddard Rosa <andre.goddard@gmail.com> wrote:
>
>> @@ -546,12 +548,12 @@ static char *number(char *buf, char *end,
>> unsigned long long num,
>>       return buf;
>>  }
>>
>> -static char *string(char *buf, char *end, char *s, struct printf_spec spec)
>> +static char *string(char *buf, char *end, const char *s, struct
>> printf_spec spec)
>
> FYI, your patches have such linewraps, so the patches wont apply:
>
>  patch: **** malformed patch at line 47: unsigned long long num,
>
> See Documentation/email-clients.txt about how to send patches without
> such problems.
>
> Mind resending with this fixed?

I tried to fix these by using send-email this time. Please let me know
if you still see any issue.

> Also, this RFC patch of yours:
>
>  vsprintf: reuse almost identical simple_strtoulX() functions
>
> looks nice too IMO - mind including it in your series?

Can I consider it as an Acked-by?  ;-)

Just sent v4 now.

Thank you,
André