perf tools: Add new 'perf data' command

Adding new 'perf data' command to provide operations over data files.

The 'perf data convert' sub command is coming in following patch, but
there's possibility for other useful commands like 'perf data ls' (to
display perf data file in directory in ls style).

Signed-off-by: Jiri Olsa <[e-mail]>
Acked-by: Namhyung Kim <[e-mail]>
Reviewed-by: David Ahern <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Jeremie Galarneau <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Sebastian Andrzej Siewior <[e-mail]>
Cc: Tom Zanussi <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Sebastian Andrzej Siewior <[e-mail]>
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Build

···
 perf-y += builtin-kvm.o
 perf-y += builtin-inject.o
 perf-y += builtin-mem.o
+perf-y += builtin-data.o
 
 perf-$(CONFIG_AUDIT) += builtin-trace.o
 perf-$(CONFIG_LIBELF) += builtin-probe.o

tools/perf/Documentation/perf-data.txt

···
+perf-data(1)
+==============
+
+NAME
+----
+perf-data - Data file related processing
+
+SYNOPSIS
+--------
+[verse]
+'perf data' [<common options>] <command> [<options>]",
+
+DESCRIPTION
+-----------
+Data file related processing.

tools/perf/builtin-data.c

···
+#include <linux/compiler.h>
+#include "builtin.h"
+#include "perf.h"
+#include "debug.h"
+#include "parse-options.h"
+
+typedef int (*data_cmd_fn_t)(int argc, const char **argv, const char *prefix);
+
+struct data_cmd {
+	const char	*name;
+	const char	*summary;
+	data_cmd_fn_t	fn;
+};
+
+static struct data_cmd data_cmds[];
+
+#define for_each_cmd(cmd) \
+	for (cmd = data_cmds; cmd && cmd->name; cmd++)
+
+static const struct option data_options[] = {
+	OPT_END()
+};
+
+static const char * const data_usage[] = {
+	"perf data [<common options>] <command> [<options>]",
+	NULL
+};
+
+static void print_usage(void)
+{
+	struct data_cmd *cmd;
+
+	printf("Usage:\n");
+	printf("\t%s\n\n", data_usage[0]);
+	printf("\tAvailable commands:\n");
+
+	for_each_cmd(cmd) {
+		printf("\t %s\t- %s\n", cmd->name, cmd->summary);
+	}
+
+	printf("\n");
+}
+
+static struct data_cmd data_cmds[] = {
+	{ NULL },
+};
+
+int cmd_data(int argc, const char **argv, const char *prefix)
+{
+	struct data_cmd *cmd;
+	const char *cmdstr;
+
+	/* No command specified. */
+	if (argc < 2)
+		goto usage;
+
+	argc = parse_options(argc, argv, data_options, data_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+	if (argc < 1)
+		goto usage;
+
+	cmdstr = argv[0];
+
+	for_each_cmd(cmd) {
+		if (strcmp(cmd->name, cmdstr))
+			continue;
+
+		return cmd->fn(argc, argv, prefix);
+	}
+
+	pr_err("Unknown command: %s\n", cmdstr);
+usage:
+	print_usage();
+	return -1;
+}

tools/perf/builtin.h

···
 extern int cmd_trace(int argc, const char **argv, const char *prefix);
 extern int cmd_inject(int argc, const char **argv, const char *prefix);
 extern int cmd_mem(int argc, const char **argv, const char *prefix);
+extern int cmd_data(int argc, const char **argv, const char *prefix);
 
 extern int find_scripts(char **scripts_array, char **scripts_path_array);
 #endif

tools/perf/command-list.txt

···
 perf-bench			mainporcelain common
 perf-buildid-cache		mainporcelain common
 perf-buildid-list		mainporcelain common
+perf-data			mainporcelain common
 perf-diff			mainporcelain common
 perf-evlist			mainporcelain common
 perf-inject			mainporcelain common

tools/perf/perf.c

···
 #endif
 	{ "inject",	cmd_inject,	0 },
 	{ "mem",	cmd_mem,	0 },
+	{ "data",	cmd_data,	0 },
 };
 
 struct pager_config {