[PATCH v2 4/8] perf tools: Support multiple sort keys in a hierarchy level

[Namhyung Kim]

This implements having multiple sort keys in a single hierarchy level.
Originally only single sort key is supported for each level, but now
using the group syntax with '{ }', it can set more than one sort key in
one level.  Note that now it needs to quote in order to prevent shell
interpretation.

For example:

  $ perf report --hierarchy -s '{comm,dso},sym'
  ...
  #       Overhead  Command / Shared Object / Symbol
  # ..............  ..........................................
  #
      48.67%        swapper          [kernel.vmlinux]
         34.42%        [k] intel_idle
          1.30%        [k] __tick_nohz_idle_enter
          1.03%        [k] cpuidle_reflect
       8.87%        firefox          libpthread-2.22.so
          6.60%        [.] __GI___libc_recvmsg
          1.18%        [.] pthread_cond_signal@@GLIBC_2.3.2
          1.09%        [.] 0x000000000000ff4b
       6.11%        Xorg             libc-2.22.so
          5.27%        [.] __memcpy_sse2_unaligned

In the above example, the command name and the shared object name are
shown on the same line but the symbol name is on the different line.
Since the first two are grouped by '{}', they are in the same level.

Suggested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
 tools/perf/util/sort.c | 42 ++++++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 71d45d147376..041f236379e0 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -2310,18 +2310,40 @@ static int setup_sort_list(char *str, struct perf_evlist *evlist)
 	char *tmp, *tok;
 	int ret = 0;
 	int level = 0;
+	int next_level = 1;
+	bool in_group = false;
+
+	do {
+		tok = str;
+		tmp = strpbrk(str, "{}, ");
+		if (tmp) {
+			if (in_group)
+				next_level = level;
+			else
+				next_level = level + 1;
+
+			if (*tmp == '{')
+				in_group = true;
+			else if (*tmp == '}')
+				in_group = false;
+
+			*tmp = '\0';
+			str = tmp + 1;
+		}
 
-	for (tok = strtok_r(str, ", ", &tmp);
-			tok; tok = strtok_r(NULL, ", ", &tmp)) {
-		ret = sort_dimension__add(tok, evlist, level++);
-		if (ret == -EINVAL) {
-			error("Invalid --sort key: `%s'", tok);
-			break;
-		} else if (ret == -ESRCH) {
-			error("Unknown --sort key: `%s'", tok);
-			break;
+		if (*tok) {
+			ret = sort_dimension__add(tok, evlist, level);
+			if (ret == -EINVAL) {
+				error("Invalid --sort key: `%s'", tok);
+				break;
+			} else if (ret == -ESRCH) {
+				error("Unknown --sort key: `%s'", tok);
+				break;
+			}
 		}
-	}
+
+		level = next_level;
+	} while (tmp);
 
 	return ret;
 }
-- 
2.7.2