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>

tools/perf/Documentation/perf-annotate.txt

@@ -22,7 +22,7 @@ OPTIONS
 -------
 -i::
 --input=::
-        Input file name. (default: perf.data)
+        Input file name. (default: perf.data unless stdin is a fifo)
 
 -d::
 --dsos=<dso[,dso...]>::

tools/perf/Documentation/perf-buildid-list.txt

@@ -26,7 +26,7 @@ OPTIONS
         Show only DSOs with hits.
 -i::
 --input=::
-        Input file name. (default: perf.data)
+        Input file name. (default: perf.data unless stdin is a fifo)
 -f::
 --force::
 	Don't do ownership validation.

tools/perf/Documentation/perf-evlist.txt

@@ -18,7 +18,7 @@ OPTIONS
 -------
 -i::
 --input=::
-        Input file name. (default: perf.data)
+        Input file name. (default: perf.data unless stdin is a fifo)
 
 SEE ALSO
 --------

tools/perf/Documentation/perf-kmem.txt

@@ -23,7 +23,7 @@ OPTIONS
 -------
 -i <file>::
 --input=<file>::
-	Select the input file (default: perf.data)
+	Select the input file (default: perf.data unless stdin is a fifo)
 
 --caller::
 	Show per-callsite statistics

tools/perf/Documentation/perf-lock.txt

@@ -29,7 +29,7 @@ COMMON OPTIONS
 
 -i::
 --input=<file>::
-        Input file name.
+        Input file name. (default: perf.data unless stdin is a fifo)
 
 -v::
 --verbose::

tools/perf/Documentation/perf-report.txt

@@ -19,7 +19,7 @@ OPTIONS
 -------
 -i::
 --input=::
-        Input file name. (default: perf.data)
+        Input file name. (default: perf.data unless stdin is a fifo)
 
 -v::
 --verbose::

tools/perf/Documentation/perf-sched.txt

@@ -40,7 +40,7 @@ OPTIONS
 -------
 -i::
 --input=<file>::
-        Input file name. (default: perf.data)
+        Input file name. (default: perf.data unless stdin is a fifo)
 
 -v::
 --verbose::

tools/perf/Documentation/perf-script.txt

@@ -106,7 +106,7 @@ OPTIONS
 
 -i::
 --input=::
-        Input file name.
+        Input file name. (default: perf.data unless stdin is a fifo)
 
 -d::
 --debug-mode::

tools/perf/Documentation/perf-timechart.txt

@@ -27,7 +27,7 @@ OPTIONS
         Select the output file (default: output.svg)
 -i::
 --input=::
-        Select the input file (default: perf.data)
+        Select the input file (default: perf.data unless stdin is a fifo)
 -w::
 --width=::
         Select the width of the SVG file (default: 1000)

tools/perf/builtin-annotate.c

@@ -215,7 +215,7 @@ static int __cmd_annotate(struct perf_annotate *ann)
 	}
 
 	if (total_nr_samples == 0) {
-		ui__warning("The %s file has no samples!\n", ann->input_name);
+		ui__warning("The %s file has no samples!\n", session->filename);
 		goto out_delete;
 	}
 out_delete:
@@ -250,7 +250,6 @@ int cmd_annotate(int argc, const char **argv, const char *prefix __used)
 			.ordered_samples = true,
 			.ordering_requires_timestamps = true,
 		},
-		.input_name = "perf.data",
 	};
 	const struct option options[] = {
 	OPT_STRING('i', "input", &annotate.input_name, "file",

tools/perf/builtin-buildid-list.c

@@ -18,7 +18,7 @@
 
 #include <libelf.h>
 
-static char const *input_name = "perf.data";
+static const char *input_name;
 static bool force;
 static bool show_kernel;
 static bool with_hits;
@@ -71,16 +71,24 @@ static int perf_session__list_build_ids(void)
 {
 	struct perf_session *session;
 
+	elf_version(EV_CURRENT);
+
 	session = perf_session__new(input_name, O_RDONLY, force, false,
 				    &build_id__mark_dso_hit_ops);
 	if (session == NULL)
 		return -1;
 
+	/*
+	 * See if this is an ELF file first:
+	 */
+	if (filename__fprintf_build_id(session->filename, stdout))
+		goto out;
+
 	if (with_hits)
 		perf_session__process_events(session, &build_id__mark_dso_hit_ops);
 
 	perf_session__fprintf_dsos_buildid(session, stdout, with_hits);
-
+out:
 	perf_session__delete(session);
 	return 0;
 }
@@ -90,13 +98,6 @@ static int __cmd_buildid_list(void)
 	if (show_kernel)
 		return sysfs__fprintf_build_id(stdout);
 
-	elf_version(EV_CURRENT);
-	/*
- 	 * See if this is an ELF file first:
- 	 */
-	if (filename__fprintf_build_id(input_name, stdout))
-		return 0;
-
 	return perf_session__list_build_ids();
 }
 

tools/perf/builtin-evlist.c

@@ -15,7 +15,7 @@
 #include "util/parse-options.h"
 #include "util/session.h"
 
-static char const *input_name = "perf.data";
+static const char *input_name;
 
 static int __cmd_evlist(void)
 {

tools/perf/builtin-kmem.c

@@ -19,7 +19,7 @@
 struct alloc_stat;
 typedef int (*sort_fn_t)(struct alloc_stat *, struct alloc_stat *);
 
-static char const		*input_name = "perf.data";
+static const char		*input_name;
 
 static int			alloc_flag;
 static int			caller_flag;

tools/perf/builtin-lock.c

@@ -326,7 +326,7 @@ static struct lock_stat *lock_stat_findnew(void *addr, const char *name)
 	die("memory allocation failed\n");
 }
 
-static char			const *input_name = "perf.data";
+static const char *input_name;
 
 struct raw_event_sample {
 	u32			size;

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 @@ parse_callchain_opt(const struct option *opt, const char *arg, int unset)
 
 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

tools/perf/builtin-sched.c

@@ -22,7 +22,7 @@
 #include <pthread.h>
 #include <math.h>
 
-static char			const *input_name = "perf.data";
+static const char		*input_name;
 
 static char			default_sort_order[] = "avg, max, switch, runtime";
 static const char		*sort_order = default_sort_order;

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);

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 */

tools/perf/util/session.c

@@ -107,8 +107,19 @@ struct perf_session *perf_session__new(const char *filename, int mode,
 				       bool force, bool repipe,
 				       struct perf_tool *tool)
 {
-	size_t len = filename ? strlen(filename) : 0;
-	struct perf_session *self = zalloc(sizeof(*self) + len);
+	struct perf_session *self;
+	struct stat st;
+	size_t len;
+
+	if (!filename || !strlen(filename)) {
+		if (!fstat(STDIN_FILENO, &st) && S_ISFIFO(st.st_mode))
+			filename = "-";
+		else
+			filename = "perf.data";
+	}
+
+	len = strlen(filename);
+	self = zalloc(sizeof(*self) + len);
 
 	if (self == NULL)
 		goto out;