[PATCH v2 0/4] perf script: Add script per-event-dump support

[yuzhoujian]

Introduce a new option to print trace output to files named by the
 monitored events and update perf-script documentation accordingly.

 Shown below is output of perf script command with the newly introduced
 option.

         $perf record -e cycles -e context-switches -ag -- sleep 10
         $perf script --per-event-dump
         $ls /
         cycles.stacks context-switches.stacks

 Without per-event-dump support, drawing flamegraphs for different events
 is really hard. You can only monitor one event at a time for perf record.
 Using this option, we can get the trace output files named by the monitored
 events, and could draw flamegraphs according to the event's name.

yuzhoujian (4):
  Add a new element for the struct perf_tool, and add the
    --per-event-dump     option for perf script
  Add fp argument to print functions
  Replace printf with fprintf for all print functions
  Makes all print functions receive the fp argument, and opens a dump   
     file in process_event.

changes in v2:
	- remove the set of script.tool.per_event_dump varible.
	- add the __maybe_unused attribute for the fp argument in the second patch.
	- remove the fp_selection_helper function for setting the fp argument.
	- split the original second patch(Makes all those related functions receive the FILE pointer) to two patches.
	- modify the file name of per-event-dump to <ORIGINAL PERF DATA FILE NAME>-script-dump-<EVENT NAME>.txt 
 tools/perf/builtin-script.c | 455 ++++++++++++++++++++++++--------------------
 tools/perf/util/tool.h      |   1 +
 2 files changed, 253 insertions(+), 203 deletions(-)

-- 
1.8.3.1