perf tools: Introduce usage_with_options_msg()

Now usage_with_options() setup a pager before printing message so normal
printf() or pr_err() will not be shown.  The usage_with_options_msg()
can be used to print some help message before usage strings.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1445701767-12731-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-evlist.c

@@ -61,8 +61,8 @@ int cmd_evlist(int argc, const char **argv, const char *prefix __maybe_unused)
 		usage_with_options(evlist_usage, options);
 
 	if (details.event_group && (details.verbose || details.freq)) {
-		pr_err("--group option is not compatible with other options\n");
-		usage_with_options(evlist_usage, options);
+		usage_with_options_msg(evlist_usage, options,
+			"--group option is not compatible with other options\n");
 	}
 
 	return __cmd_evlist(input_name, &details);

tools/perf/builtin-probe.c

@@ -528,12 +528,12 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 			     PARSE_OPT_STOP_AT_NON_OPTION);
 	if (argc > 0) {
 		if (strcmp(argv[0], "-") == 0) {
-			pr_warning("  Error: '-' is not supported.\n");
-			usage_with_options(probe_usage, options);
+			usage_with_options_msg(probe_usage, options,
+				"'-' is not supported.\n");
 		}
 		if (params.command && params.command != 'a') {
-			pr_warning("  Error: another command except --add is set.\n");
-			usage_with_options(probe_usage, options);
+			usage_with_options_msg(probe_usage, options,
+				"another command except --add is set.\n");
 		}
 		ret = parse_probe_event_argv(argc, argv);
 		if (ret < 0) {
@@ -562,8 +562,10 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 	switch (params.command) {
 	case 'l':
 		if (params.uprobes) {
-			pr_warning("  Error: Don't use --list with --exec.\n");
-			usage_with_options(probe_usage, options);
+			pr_err("  Error: Don't use --list with --exec.\n");
+			parse_options_usage(probe_usage, options, "l", true);
+			parse_options_usage(NULL, options, "x", true);
+			return -EINVAL;
 		}
 		ret = show_perf_probe_events(params.filter);
 		if (ret < 0)
@@ -603,8 +605,10 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 	case 'a':
 		/* Ensure the last given target is used */
 		if (params.target && !params.target_used) {
-			pr_warning("  Error: -x/-m must follow the probe definitions.\n");
-			usage_with_options(probe_usage, options);
+			pr_err("  Error: -x/-m must follow the probe definitions.\n");
+			parse_options_usage(probe_usage, options, "m", true);
+			parse_options_usage(NULL, options, "x", true);
+			return -EINVAL;
 		}
 
 		ret = perf_add_probe_events(params.events, params.nevents);

tools/perf/builtin-record.c

@@ -1135,14 +1135,15 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 		usage_with_options(record_usage, record_options);
 
 	if (nr_cgroups && !rec->opts.target.system_wide) {
-		ui__error("cgroup monitoring only available in"
-			  " system-wide mode\n");
-		usage_with_options(record_usage, record_options);
+		usage_with_options_msg(record_usage, record_options,
+			"cgroup monitoring only available in system-wide mode");
+
 	}
 	if (rec->opts.record_switch_events &&
 	    !perf_can_record_switch_events()) {
-		ui__error("kernel does not support recording context switch events (--switch-events option)\n");
-		usage_with_options(record_usage, record_options);
+		ui__error("kernel does not support recording context switch events\n");
+		parse_options_usage(record_usage, record_options, "switch-events", 0);
+		return -EINVAL;
 	}
 
 	if (!rec->itr) {

tools/perf/builtin-sched.c

@@ -1728,8 +1728,8 @@ static void setup_sorting(struct perf_sched *sched, const struct option *options
 	for (tok = strtok_r(str, ", ", &tmp);
 			tok; tok = strtok_r(NULL, ", ", &tmp)) {
 		if (sort_dimension__add(tok, &sched->sort_list) < 0) {
-			error("Unknown --sort key: `%s'", tok);
-			usage_with_options(usage_msg, options);
+			usage_with_options_msg(usage_msg, options,
+					"Unknown --sort key: `%s'", tok);
 		}
 	}
 

tools/perf/builtin-script.c

@@ -1767,9 +1767,9 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
 		rep_script_path = get_script_path(argv[0], REPORT_SUFFIX);
 
 		if (!rec_script_path && !rep_script_path) {
-			fprintf(stderr, " Couldn't find script %s\n\n See perf"
+			usage_with_options_msg(script_usage, options,
+				"Couldn't find script `%s'\n\n See perf"
 				" script -l for available scripts.\n", argv[0]);
-			usage_with_options(script_usage, options);
 		}
 
 		if (is_top_script(argv[0])) {
@@ -1780,10 +1780,10 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
 			rep_args = has_required_arg(rep_script_path);
 			rec_args = (argc - 1) - rep_args;
 			if (rec_args < 0) {
-				fprintf(stderr, " %s script requires options."
+				usage_with_options_msg(script_usage, options,
+					"`%s' script requires options."
 					"\n\n See perf script -l for available "
 					"scripts and options.\n", argv[0]);
-				usage_with_options(script_usage, options);
 			}
 		}
 

tools/perf/util/parse-options.c

@@ -760,6 +760,21 @@ void usage_with_options(const char * const *usagestr,
 	exit(129);
 }
 
+void usage_with_options_msg(const char * const *usagestr,
+			    const struct option *opts, const char *fmt, ...)
+{
+	va_list ap;
+
+	exit_browser(false);
+
+	va_start(ap, fmt);
+	strbuf_addv(&error_buf, fmt, ap);
+	va_end(ap);
+
+	usage_with_options_internal(usagestr, opts, 0, NULL);
+	exit(129);
+}
+
 int parse_options_usage(const char * const *usagestr,
 			const struct option *opts,
 			const char *optstr, bool short_opt)

tools/perf/util/parse-options.h

@@ -161,6 +161,10 @@ extern int parse_options_subcommand(int argc, const char **argv,
 
 extern NORETURN void usage_with_options(const char * const *usagestr,
                                         const struct option *options);
+extern NORETURN __attribute__((format(printf,3,4)))
+void usage_with_options_msg(const char * const *usagestr,
+			    const struct option *options,
+			    const char *fmt, ...);
 
 /*----- incremantal advanced APIs -----*/
 

tools/perf/util/strbuf.c

@@ -82,23 +82,22 @@ void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 	strbuf_setlen(sb, sb->len + len);
 }
 
-void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
+void strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
 {
 	int len;
-	va_list ap;
+	va_list ap_saved;
 
 	if (!strbuf_avail(sb))
 		strbuf_grow(sb, 64);
-	va_start(ap, fmt);
+
+	va_copy(ap_saved, ap);
 	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
-	va_end(ap);
 	if (len < 0)
 		die("your vsnprintf is broken");
 	if (len > strbuf_avail(sb)) {
 		strbuf_grow(sb, len);
-		va_start(ap, fmt);
-		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
-		va_end(ap);
+		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
+		va_end(ap_saved);
 		if (len > strbuf_avail(sb)) {
 			die("this should not happen, your vsnprintf is broken");
 		}
@@ -106,6 +105,15 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 	strbuf_setlen(sb, sb->len + len);
 }
 
+void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	strbuf_addv(sb, fmt, ap);
+	va_end(ap);
+}
+
 ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
 {
 	size_t oldlen = sb->len;

tools/perf/util/strbuf.h

@@ -39,6 +39,7 @@
  */
 
 #include <assert.h>
+#include <stdarg.h>
 
 extern char strbuf_slopbuf[];
 struct strbuf {
@@ -85,6 +86,7 @@ static inline void strbuf_addstr(struct strbuf *sb, const char *s) {
 
 __attribute__((format(printf,2,3)))
 extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
+extern void strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap);
 
 /* XXX: if read fails, any partial read is undone */
 extern ssize_t strbuf_read(struct strbuf *, int fd, ssize_t hint);