From a14832ff977e78d1982cdf78cdabb1f2320d9ac8 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Sun, 7 Jun 2009 17:58:23 +0200
Subject: [PATCH] perf report: Print more expressive message in case of file
 open error

Before:

 $ perf report
 failed to open file: No such file or directory

After:

 $ perf report
  failed to open file: perf.data  (try 'perf record' first)

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 tools/perf/builtin-report.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 242e09ff365..f053a7463dc 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1120,7 +1120,10 @@ static int __cmd_report(void)
 
 	input = open(input_name, O_RDONLY);
 	if (input < 0) {
-		perror("failed to open file");
+		fprintf(stderr, " failed to open file: %s", input_name);
+		if (!strcmp(input_name, "perf.data"))
+			fprintf(stderr, "  (try 'perf record' first)");
+		fprintf(stderr, "\n");
 		exit(-1);
 	}