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 <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-5-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 135376a37f97..3b75b2e21ea5 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -38,8 +38,8 @@
 #define PWR_EVENT_EXIT -1
 
 
-static char		const *input_name = "perf.data";
-static char		const *output_name = "output.svg";
+static const char	*input_name;
+static const char	*output_name = "output.svg";
 
 static unsigned int	numcpus;
 static u64		min_freq;	/* Lowest CPU frequency seen */