perf report: Accept fifos as input file

The default input file for perf report is not handled the same way as
perf record does it for its output file. This leads to unexpected
behavior of perf report, etc. E.g.:

 # perf record -a -e cpu-cycles sleep 2 | perf report | cat
 failed to open perf.data: No such file or directory  (try 'perf record' first)

While perf record writes to a fifo, perf report expects perf.data to be
read. This patch changes this to accept fifos as input file.

Applies to the following commands:

 perf annotate
 perf buildid-list
 perf evlist
 perf kmem
 perf lock
 perf report
 perf sched
 perf script
 perf timechart

Also fixes char const* -> const char* type declaration for filename
strings.

v2:
* Prevent potential null pointer access to input_name in
  builtin-report.c. Needed due to removal of patch "perf report: Setup
  browser if stdout is a pipe"

Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Robert Richter <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index d71b745da06e..3d4c0c7b576e 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -434,7 +434,7 @@ static int cleanup_scripting(void)
 	return scripting_ops->stop_script();
 }
 
-static char const		*input_name = "perf.data";
+static const char *input_name;
 
 static int process_sample_event(struct perf_tool *tool __used,
 				union perf_event *event,
@@ -1316,7 +1316,7 @@ int cmd_script(int argc, const char **argv, const char *prefix __used)
 			return -1;
 		}
 
-		input = open(input_name, O_RDONLY);
+		input = open(session->filename, O_RDONLY);	/* input_name */
 		if (input < 0) {
 			perror("failed to open file");
 			exit(-1);