perf tools: Add --buildid-dir option to set cache directory

Adding --buildid-dir to be able to set specific cache directory. It's
going to be handy for buildid tests coming in shortly.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1417460789-13874-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf.txt

@@ -18,6 +18,10 @@ OPTIONS
 	  --debug verbose   # sets verbose = 1
 	  --debug verbose=2 # sets verbose = 2
 
+--buildid-dir::
+	Setup buildid cache directory. It has higher priority than
+	buildid.dir config file option.
+
 DESCRIPTION
 -----------
 Performance counters for Linux are a new kernel-based subsystem

tools/perf/perf.c

@@ -200,6 +200,16 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 				*envchanged = 1;
 			(*argv)++;
 			(*argc)--;
+		} else if (!strcmp(cmd, "--buildid-dir")) {
+			if (*argc < 2) {
+				fprintf(stderr, "No directory given for --buildid-dir.\n");
+				usage(perf_usage_string);
+			}
+			set_buildid_dir((*argv)[1]);
+			if (envchanged)
+				*envchanged = 1;
+			(*argv)++;
+			(*argc)--;
 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
 			perf_debugfs_set_path(cmd + strlen(CMD_DEBUGFS_DIR));
 			fprintf(stderr, "dir: %s\n", debugfs_mountpoint);
@@ -499,7 +509,7 @@ int main(int argc, const char **argv)
 	}
 	if (!prefixcmp(cmd, "trace")) {
 #ifdef HAVE_LIBAUDIT_SUPPORT
-		set_buildid_dir();
+		set_buildid_dir(NULL);
 		setup_path();
 		argv[0] = "trace";
 		return cmd_trace(argc, argv, NULL);
@@ -514,7 +524,7 @@ int main(int argc, const char **argv)
 	argc--;
 	handle_options(&argv, &argc, NULL);
 	commit_pager_choice();
-	set_buildid_dir();
+	set_buildid_dir(NULL);
 
 	if (argc > 0) {
 		if (!prefixcmp(argv[0], "--"))

tools/perf/util/config.c

@@ -539,12 +539,14 @@ static void check_buildid_dir_config(void)
 	perf_config(buildid_dir_command_config, &c);
 }
 
-void set_buildid_dir(void)
+void set_buildid_dir(const char *dir)
 {
-	buildid_dir[0] = '\0';
+	if (dir)
+		scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
 
 	/* try config file */
-	check_buildid_dir_config();
+	if (buildid_dir[0] == '\0')
+		check_buildid_dir_config();
 
 	/* default to $HOME/.debug */
 	if (buildid_dir[0] == '\0') {

tools/perf/util/util.h

@@ -153,7 +153,7 @@ extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)))
 extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
 
 extern int prefixcmp(const char *str, const char *prefix);
-extern void set_buildid_dir(void);
+extern void set_buildid_dir(const char *dir);
 
 static inline const char *skip_prefix(const char *str, const char *prefix)
 {