tools lib: Move argv_{split,free} from tools/perf/util/

This came from the kernel lib/argv_split.c, so move it to
tools/lib/argv_split.c, to get it closer to the kernel structure.

We need to audit the usage of argv_split() to figure out if it is really
necessary to do have one allocation per argv[] entry, looking at one of
its users I guess that is not the case and we probably are even leaking
those allocations by not using argv_free() judiciously, for later.

With this we further remove stuff from tools/perf/util/, reducing the
perf specific codebase and encouraging other tools/ code to use these
routines so as to keep the style and constructs used with the kernel.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-j479s1ive9h75w5lfg16jroz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/include/linux/string.h

@@ -7,6 +7,9 @@
 
 void *memdup(const void *src, size_t len);
 
+char **argv_split(const char *str, int *argcp);
+void argv_free(char **argv);
+
 int strtobool(const char *s, bool *res);
 
 /*

tools/lib/argv_split.c

@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helper function for splitting a string into an argv-like array.
+ */
+
+#include <stdlib.h>
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/string.h>
+
+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_spaces(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);
+		*p = NULL;
+	}
+
+	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 = calloc(argc + 1, sizeof(*argv));
+	char **argvp;
+
+	if (argv == NULL)
+		goto out;
+
+	if (argcp)
+		*argcp = argc;
+
+	argvp = argv;
+
+	while (*str) {
+		str = skip_spaces(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;
+}

tools/perf/MANIFEST

@@ -7,6 +7,7 @@ tools/lib/traceevent
 tools/lib/api
 tools/lib/bpf
 tools/lib/subcmd
+tools/lib/argv_split.c
 tools/lib/ctype.c
 tools/lib/hweight.c
 tools/lib/rbtree.c

tools/perf/util/Build

@@ -20,6 +20,7 @@ perf-y += parse-events.o
 perf-y += perf_regs.o
 perf-y += path.o
 perf-y += print_binary.o
+perf-y += argv_split.o
 perf-y += rbtree.o
 perf-y += libstring.o
 perf-y += bitmap.o
@@ -209,6 +210,10 @@ $(OUTPUT)util/kallsyms.o: ../lib/symbol/kallsyms.c FORCE
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)
 
+$(OUTPUT)util/argv_split.o: ../lib/argv_split.c FORCE
+	$(call rule_mkdir)
+	$(call if_changed_dep,cc_o_c)
+
 $(OUTPUT)util/bitmap.o: ../lib/bitmap.c FORCE
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)

tools/perf/util/string.c

@@ -69,97 +69,6 @@ s64 perf_atoll(const char *str)
 	return -1;
 }
 
-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_spaces(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);
-		*p = NULL;
-	}
-
-	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 = calloc(argc + 1, sizeof(*argv));
-	char **argvp;
-
-	if (argv == NULL)
-		goto out;
-
-	if (argcp)
-		*argcp = argc;
-
-	argvp = argv;
-
-	while (*str) {
-		str = skip_spaces(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;
-}
-
 /* Character class matching */
 static bool __match_charclass(const char *pat, char c, const char **npat)
 {

tools/perf/util/string2.h

@@ -11,8 +11,6 @@ extern const char *graph_dotted_line;
 extern const char *dots;
 
 s64 perf_atoll(const char *str);
-char **argv_split(const char *str, int *argcp);
-void argv_free(char **argv);
 bool strglobmatch(const char *str, const char *pat);
 bool strglobmatch_nocase(const char *str, const char *pat);
 bool strlazymatch(const char *str, const char *pat);