perf tools: Add +field argument support for --sort option

Adding support to add field(s) to default sort order via using the '+'
prefix, like for report:

  $ perf report
  Samples: 2K of event 'cycles', Event count (approx.): 882172583
  Overhead  Command  Shared Object        Symbol
     7.39%  swapper  [kernel.kallsyms]    [k] intel_idle
     1.97%  firefox  libpthread-2.17.so   [.] pthread_mutex_lock
     1.39%  firefox  [snd_hda_intel]      [k] azx_get_position
     1.11%  firefox  libpthread-2.17.so   [.] pthread_mutex_unlock

  $ perf report -s +cpu
  Samples: 2K of event 'cycles', Event count (approx.): 882172583
  Overhead  Command  Shared Object        Symbol                  CPU
     2.89%  swapper  [kernel.kallsyms]    [k] intel_idle          000
     2.61%  swapper  [kernel.kallsyms]    [k] intel_idle          002
     1.20%  swapper  [kernel.kallsyms]    [k] intel_idle          001
     0.82%  firefox  libpthread-2.17.so   [.] pthread_mutex_lock  002

Works in general for commands using --sort option.

v2 with changes suggested:
  - Use dynamic memory instead static buffer
  - Fix error message typo

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140823125948.GA1193@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 1958637..289df9d 100644 (file)
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -1446,12 +1446,47 @@ static const char *get_default_sort_order(void)
        return default_sort_orders[sort__mode];
 }
 
+static int setup_sort_order(void)
+{
+       char *new_sort_order;
+
+       /*
+        * Append '+'-prefixed sort order to the default sort
+        * order string.
+        */
+       if (!sort_order || is_strict_order(sort_order))
+               return 0;
+
+       if (sort_order[1] == '\0') {
+               error("Invalid --sort key: `+'");
+               return -EINVAL;
+       }
+
+       /*
+        * We allocate new sort_order string, but we never free it,
+        * because it's checked over the rest of the code.
+        */
+       if (asprintf(&new_sort_order, "%s,%s",
+                    get_default_sort_order(), sort_order + 1) < 0) {
+               error("Not enough memory to set up --sort");
+               return -ENOMEM;
+       }
+
+       sort_order = new_sort_order;
+       return 0;
+}
+
 static int __setup_sorting(void)
 {
        char *tmp, *tok, *str;
-       const char *sort_keys = sort_order;
+       const char *sort_keys;
        int ret = 0;
 
+       ret = setup_sort_order();
+       if (ret)
+               return ret;
+
+       sort_keys = sort_order;
        if (sort_keys == NULL) {
                if (is_strict_order(field_order)) {
                        /*