perf tools: Save cmdline arguments earlier

perf_env__set_cmdline() only saves the arguments the first time it's
called.  It doesn't need to be called every time the options and
suboptions are parsed.  Instead it can just be called once.

This also has the advantage of making the option parsing code less
perf-specific so it can be moved out to a library.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/19b76a5aa1b688bd635bd65d80bbc103a978d75e.1449548395.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/perf.c

@@ -384,6 +384,7 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 		use_pager = 1;
 	commit_pager_choice();
 
+	perf_env__set_cmdline(&perf_env, argc, argv);
 	status = p->fn(argc, argv, prefix);
 	exit_browser(status);
 	perf_env__exit(&perf_env);

tools/perf/util/env.c

@@ -25,15 +25,6 @@ int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
 {
 	int i;
 
-	/*
-	 * If env->cmdline_argv has already been set, do not override it.  This allows
-	 * a command to set the cmdline, parse args and then call another
-	 * builtin function that implements a command -- e.g, cmd_kvm calling
-	 * cmd_record.
-	 */
-	if (env->cmdline_argv != NULL)
-		return 0;
-
 	/* do not include NULL termination */
 	env->cmdline_argv = calloc(argc, sizeof(char *));
 	if (env->cmdline_argv == NULL)

tools/perf/util/parse-options.c

@@ -501,8 +501,6 @@ int parse_options_subcommand(int argc, const char **argv, const struct option *o
 {
 	struct parse_opt_ctx_t ctx;
 
-	perf_env__set_cmdline(&perf_env, argc, argv);
-
 	/* build usage string if it's not provided */
 	if (subcommands && !usagestr[0]) {
 		struct strbuf buf = STRBUF_INIT;