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![André Goddard Rosa](/assets/img/avatar_default.png)
Makes use of skip_spaces() defined in lib/string.c for removing leading spaces from strings all over the tree. It decreases lib.a code size by 47 bytes and reuses the function tree-wide: text data bss dec hex filename 64688 584 592 65864 10148 (TOTALS-BEFORE) 64641 584 592 65817 10119 (TOTALS-AFTER) Also, while at it, if we see (*str && isspace(*str)), we can be sure to remove the first condition (*str) as the second one (isspace(*str)) also evaluates to 0 whenever *str == 0, making it redundant. In other words, "a char equals zero is never a space". Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below, and found occurrences of this pattern on 3 more files: drivers/leds/led-class.c drivers/leds/ledtrig-timer.c drivers/video/output.c @@ expression str; @@ ( // ignore skip_spaces cases while (*str && isspace(*str)) { \(str++;\|++str;\) } | - *str && isspace(*str) ) Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Cc: Julia Lawall <julia@diku.dk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Neil Brown <neilb@suse.de> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: David Howells <dhowells@redhat.com> Cc: <linux-ext4@vger.kernel.org> Cc: Samuel Ortiz <samuel@sortiz.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
101 lines
1.8 KiB
C
101 lines
1.8 KiB
C
/*
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* Helper function for splitting a string into an argv-like array.
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*/
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#include <linux/kernel.h>
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#include <linux/ctype.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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static const char *skip_arg(const char *cp)
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{
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while (*cp && !isspace(*cp))
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cp++;
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return cp;
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}
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static int count_argc(const char *str)
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{
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int count = 0;
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while (*str) {
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str = skip_spaces(str);
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if (*str) {
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count++;
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str = skip_arg(str);
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}
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}
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return count;
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}
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/**
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* argv_free - free an argv
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* @argv - the argument vector to be freed
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*
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* Frees an argv and the strings it points to.
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*/
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void argv_free(char **argv)
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{
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char **p;
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for (p = argv; *p; p++)
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kfree(*p);
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kfree(argv);
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}
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EXPORT_SYMBOL(argv_free);
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/**
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* argv_split - split a string at whitespace, returning an argv
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* @gfp: the GFP mask used to allocate memory
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* @str: the string to be split
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* @argcp: returned argument count
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*
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* Returns an array of pointers to strings which are split out from
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* @str. This is performed by strictly splitting on white-space; no
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* quote processing is performed. Multiple whitespace characters are
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* considered to be a single argument separator. The returned array
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* is always NULL-terminated. Returns NULL on memory allocation
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* failure.
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*/
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char **argv_split(gfp_t gfp, const char *str, int *argcp)
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{
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int argc = count_argc(str);
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char **argv = kzalloc(sizeof(*argv) * (argc+1), gfp);
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char **argvp;
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if (argv == NULL)
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goto out;
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if (argcp)
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*argcp = argc;
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argvp = argv;
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while (*str) {
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str = skip_spaces(str);
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if (*str) {
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const char *p = str;
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char *t;
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str = skip_arg(str);
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t = kstrndup(p, str-p, gfp);
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if (t == NULL)
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goto fail;
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*argvp++ = t;
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}
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}
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*argvp = NULL;
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out:
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return argv;
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fail:
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argv_free(argv);
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return NULL;
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}
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EXPORT_SYMBOL(argv_split);
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