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, 10 insertions, 3 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 9051f6bfaa7..25d34d483e4 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -321,8 +321,7 @@ static int __cmd_report(struct perf_report *rep)
 	}
 
 	if (nr_samples == 0) {
-		ui__warning("The %s file has no samples!\n",
-			    rep->input_name);
+		ui__warning("The %s file has no samples!\n", session->filename);
 		goto out_delete;
 	}
 
@@ -430,6 +429,7 @@ setup:
 
 int cmd_report(int argc, const char **argv, const char *prefix __used)
 {
+	struct stat st;
 	char callchain_default_opt[] = "fractal,0.5,callee";
 	const char * const report_usage[] = {
 		"perf report [<options>]",
@@ -451,7 +451,6 @@ int cmd_report(int argc, const char **argv, const char *prefix __used)
 			.ordered_samples = true,
 			.ordering_requires_timestamps = true,
 		},
-		.input_name		 = "perf.data",
 		.pretty_printing_style	 = "normal",
 	};
 	const struct option options[] = {
@@ -531,10 +530,18 @@ int cmd_report(int argc, const char **argv, const char *prefix __used)
 	if (report.inverted_callchain)
 		callchain_param.order = ORDER_CALLER;
 
+	if (!report.input_name || !strlen(report.input_name)) {
+		if (!fstat(STDIN_FILENO, &st) && S_ISFIFO(st.st_mode))
+			report.input_name = "-";
+		else
+			report.input_name = "perf.data";
+	}
+
 	if (strcmp(report.input_name, "-") != 0)
 		setup_browser(true);
 	else
 		use_browser = 0;
+
 	/*
 	 * Only in the newt browser we are doing integrated annotation,
 	 * so don't allocate extra space that won't be used in the stdio