From: André Goddard Rosa Date: Tue, 15 Dec 2009 02:00:55 +0000 (-0800) Subject: vsprintf: factorize "(null)" string X-Git-Tag: v2.6.33-rc1~133 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=0f4f81dce93774a447da3ceb98cce193ef84a3fa;hp=3768f0b1d18369bbb4ddc3adca791d26704e8047 vsprintf: factorize "(null)" string This patchset reduces lib/lib.a code size by 482 bytes on my Core 2 with gcc 4.4.1 even considering that it exports a newly defined function skip_spaces() to drivers: text data bss dec hex filename 64867 840 592 66299 102fb (TOTALS-lib.a-BEFORE) 64641 584 592 65817 10119 (TOTALS-lib.a-AFTER) and implements some code tidy up. Besides reducing lib.a size, it converts many in-tree drivers to use the newly defined function, which makes another small reduction on kernel size overall when those drivers are used. This patch: Change "" to "(null)", unifying 3 equal strings. glibc also uses "(null)" for the same purpose. It decreases code size by 7 bytes: text data bss dec hex filename 15765 0 8 15773 3d9d vsprintf.o (ex lib/lib.a-BEFORE) 15758 0 8 15766 3d96 vsprintf.o (ex lib/lib.a-AFTER) Signed-off-by: André Goddard Rosa Acked-by: Frederic Weisbecker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 6438cd5..e5ab51f 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -546,12 +546,12 @@ 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 = ""; + s = "(null)"; len = strnlen(s, spec.precision); @@ -1498,7 +1498,7 @@ do { \ size_t len; if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE || (unsigned long)save_str < PAGE_SIZE) - save_str = ""; + save_str = "(null)"; len = strlen(save_str); if (str + len + 1 < end) memcpy(str, save_str, len + 1);