perf probe: Add argv_split() from lib/argv_split.c

Add argv_split() ported from lib/argv_split.c to string.c and
use it in util/probe-event.c.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091201002005.10235.55602.stgit@harusame>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 118 insertions, 40 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 7335a3b5e494..e3a683ab976f 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -32,6 +32,7 @@
 
 #undef _GNU_SOURCE
 #include "event.h"
+#include "string.h"
 #include "debug.h"
 #include "parse-events.h"  /* For debugfs_path */
 #include "probe-event.h"
@@ -132,62 +133,36 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
 /* Parse perf-probe event definition */
 int parse_perf_probe_event(const char *str, struct probe_point *pp)
 {
-        char *argv[MAX_PROBE_ARGS + 1]; /* probe + args */
+        char **argv;
         int argc, i, need_dwarf = 0;
 
-        /* Separate arguments, similar to argv_split */
-        argc = 0;
-        do {
-                /* Skip separators */
-                while (isspace(*str))
-                        str++;
-
-                /* Add an argument */
-                if (*str != '\0') {
-                        const char *s = str;
-                        /* Check the limit number of arguments */
-                        if (argc == MAX_PROBE_ARGS + 1)
-                                semantic_error("Too many arguments");
-
-                        /* Skip the argument */
-                        while (!isspace(*str) && *str != '\0')
-                                str++;
-
-                        /* Duplicate the argument */
-                        argv[argc] = strndup(s, str - s);
-                        if (argv[argc] == NULL)
-                                die("strndup");
-                        pr_debug("argv[%d]=%s\n", argc, argv[argc]);
-                        argc++;
-                }
-        } while (*str != '\0');
-        if (!argc)
-                semantic_error("An empty argument.");
+        argv = argv_split(str, &argc);
+        if (!argv)
+                die("argv_split failed.");
+        if (argc > MAX_PROBE_ARGS + 1)
+                semantic_error("Too many arguments");
 
         /* Parse probe point */
         parse_perf_probe_probepoint(argv[0], pp);
-        free(argv[0]);
         if (pp->file || pp->line)
                 need_dwarf = 1;
 
-        /* Copy arguments */
+        /* Copy arguments and ensure return probe has no C argument */
         pp->nr_args = argc - 1;
-        if (pp->nr_args > 0) {
-                pp->args = (char **)malloc(sizeof(char *) * pp->nr_args);
-                if (!pp->args)
-                        die("malloc");
-                memcpy(pp->args, &argv[1], sizeof(char *) * pp->nr_args);
-        }
-
-        /* Ensure return probe has no C argument */
-        for (i = 0; i < pp->nr_args; i++)
+        pp->args = zalloc(sizeof(char *) * pp->nr_args);
+        for (i = 0; i < pp->nr_args; i++) {
+                pp->args[i] = strdup(argv[i + 1]);
+                if (!pp->args[i])
+                        die("Failed to copy argument.");
                 if (is_c_varname(pp->args[i])) {
                         if (pp->retprobe)
                                 semantic_error("You can't specify local"
                                                 " variable for kretprobe");
                         need_dwarf = 1;
                 }
+        }
 
+        argv_free(argv);
         return need_dwarf;
 }
 
diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
index 227043577e06..0977cf431789 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);
+                        if (t == NULL)
+                                goto fail;
+                        *argvp++ = t;
+                }
+        }
+        *argvp = NULL;
+
+out:
+        return argv;
+
+fail:
+        argv_free(argv);
+        return NULL;
+}
diff --git a/tools/perf/util/string.h b/tools/perf/util/string.h
index e50b07f80827..bfecec265a1a 100644
--- a/tools/perf/util/string.h
+++ b/tools/perf/util/string.h
@@ -6,6 +6,8 @@
 int hex2u64(const char *ptr, u64 *val);
 char *strxfrchar(char *s, char from, char to);
 s64 perf_atoll(const char *str);
+char **argv_split(const char *str, int *argcp);
+void argv_free(char **argv);
 
 #define _STR(x) #x
 #define STR(x) _STR(x)