Re: [tip:perf/core] perf probe: Add argv_split() from lib/argv_split.c

[Wang Liming <liming.wang@windriver.com>]

Hi Masami,

tip-bot for Masami Hiramatsu wrote:
...
> diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
> index 2270435..0977cf4 100644
> --- a/tools/perf/util/string.c
> +++ b/tools/perf/util/string.c
> @@ -127,3 +127,104 @@ out_err:
>  out:
>  	return length;
>  }
> +
> +/*
> + * Helper function for splitting a string into an argv-like array.
> + * originaly copied from lib/argv_split.c
> + */
> +static const char *skip_sep(const char *cp)
> +{
> +	while (*cp && isspace(*cp))
> +		cp++;
> +
> +	return cp;
> +}
> +
> +static const char *skip_arg(const char *cp)
> +{
> +	while (*cp && !isspace(*cp))
> +		cp++;
> +
> +	return cp;
> +}
> +
> +static int count_argc(const char *str)
> +{
> +	int count = 0;
> +
> +	while (*str) {
> +		str = skip_sep(str);
> +		if (*str) {
> +			count++;
> +			str = skip_arg(str);
> +		}
> +	}
> +
> +	return count;
> +}
> +
> +/**
> + * argv_free - free an argv
> + * @argv - the argument vector to be freed
> + *
> + * Frees an argv and the strings it points to.
> + */
> +void argv_free(char **argv)
> +{
> +	char **p;
> +	for (p = argv; *p; p++)
> +		free(*p);
> +
> +	free(argv);
> +}
> +
> +/**
> + * argv_split - split a string at whitespace, returning an argv
> + * @str: the string to be split
> + * @argcp: returned argument count
> + *
> + * Returns an array of pointers to strings which are split out from
> + * @str.  This is performed by strictly splitting on white-space; no
> + * quote processing is performed.  Multiple whitespace characters are
> + * considered to be a single argument separator.  The returned array
> + * is always NULL-terminated.  Returns NULL on memory allocation
> + * failure.
> + */
> +char **argv_split(const char *str, int *argcp)
> +{
> +	int argc = count_argc(str);
> +	char **argv = zalloc(sizeof(*argv) * (argc+1));
> +	char **argvp;
> +
> +	if (argv == NULL)
> +		goto out;
> +
> +	if (argcp)
> +		*argcp = argc;
> +
> +	argvp = argv;
> +
> +	while (*str) {
> +		str = skip_sep(str);
> +
> +		if (*str) {
> +			const char *p = str;
> +			char *t;
> +
> +			str = skip_arg(str);
> +
> +			t = strndup(p, str-p);
When I compiled "perf", I encountered following error:

     CC util/string.o
cc1: warnings being treated as errors
util/string.c: In function 'argv_split':
util/string.c:216: warning: implicit declaration of function 'strndup'
util/string.c:216: warning: incompatible implicit declaration of built-in 
function 'strndup'
make: *** [util/string.o] Error 1

Do we need to define _GNU_SOURCE in the head? Or maybe I used rather old glibc 
version.

diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
index 0977cf4..ea3eb39 100644
--- a/tools/perf/util/string.c
+++ b/tools/perf/util/string.c
@@ -1,5 +1,8 @@
+#define _GNU_SOURCE
  #include <string.h>
  #include <stdlib.h>
+
+#undef _GNU_SOURCE
  #include "string.h"
  #include "util.h"