[tip:perf/urgent] perf auxtrace: Improve address filter error message when there is no DSO

[tip-bot for Adrian Hunter]

Commit-ID:  c1c49204b0114daf210c79d66a5980c8e6f8f8fb
Gitweb:     https://git.kernel.org/tip/c1c49204b0114daf210c79d66a5980c8e6f8f8fb
Author:     Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Fri, 1 Mar 2019 14:29:02 +0200
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 1 Mar 2019 14:47:06 -0300

perf auxtrace: Improve address filter error message when there is no DSO

The message does not indicate the possibility that the symbol is not
found because the file does not exist.

Before:

  $ perf record -e intel_pt//u --filter 'filter strcmp / strcpy @ foo ' ls
  Symbol 'strcmp' not found.
  Note that symbols must be functions.
  Failed to parse address filter: 'filter strcmp / strcpy @ foo '
  Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
  Where multiple filters are separated by space or comma.

After:

  $ perf record -e intel_pt//u --filter 'filter strcmp / strcpy @ foo ' ls
  File 'foo' not found or has no symbols.
  Symbol 'strcmp' not found.
  Note that symbols must be functions.
  Failed to parse address filter: 'filter strcmp / strcpy @ foo '
  Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
  Where multiple filters are separated by space or comma.

Reported-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-dvngzxd0jkplzw1ary69dilb@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/auxtrace.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index 267e54df511b..fb76b6b232d4 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -1918,7 +1918,8 @@ static struct dso *load_dso(const char *name)
 	if (!map)
 		return NULL;
 
-	map__load(map);
+	if (map__load(map) < 0)
+		pr_err("File '%s' not found or has no symbols.\n", name);
 
 	dso = dso__get(map->dso);