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

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

  $ perf report
  Samples: 10  of event 'cycles', Event count (approx.): 4463799
  Overhead  Command  Shared Object      Symbol
    32.40%  ls       [kernel.kallsyms]  [k] filemap_fault
    28.19%  ls       [kernel.kallsyms]  [k] get_page_from_freelist
    23.38%  ls       [kernel.kallsyms]  [k] enqueue_entity
    15.04%  ls       [kernel.kallsyms]  [k] mmap_region

  $ perf report -F +period,sample
  Samples: 10  of event 'cycles', Event count (approx.): 4463799
  Overhead        Period       Samples  Command  Shared Object      Symbol
    32.40%       1446493             1  ls       [kernel.kallsyms]  [k] filemap_fault
    28.19%       1258486             1  ls       [kernel.kallsyms]  [k] get_page_from_freelist
    23.38%       1043754             1  ls       [kernel.kallsyms]  [k] enqueue_entity
    15.04%        671160             1  ls       [kernel.kallsyms]  [k] mmap_region

Works in general for commands using --field option.
Signed-off-by: Jiri Olsa <jolsa@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: 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/1408715919-25990-2-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/hist.c

@@ -452,7 +452,7 @@ void perf_hpp__init(void)
 	/*
 	 * If user specified field order, no need to setup default fields.
 	 */
-	if (field_order)
+	if (is_strict_order(field_order))
 		return;
 
 	if (symbol_conf.cumulate_callchain) {
@@ -519,7 +519,7 @@ void perf_hpp__column_disable(unsigned col)
 
 void perf_hpp__cancel_cumulate(void)
 {
-	if (field_order)
+	if (is_strict_order(field_order))
 		return;
 
 	perf_hpp__column_disable(PERF_HPP__OVERHEAD_ACC);

tools/perf/util/sort.c

@@ -1453,7 +1453,7 @@ static int __setup_sorting(void)
 	int ret = 0;
 
 	if (sort_keys == NULL) {
-		if (field_order) {
+		if (is_strict_order(field_order)) {
 			/*
 			 * If user specified field order but no sort order,
 			 * we'll honor it and not add default sort orders.
@@ -1639,23 +1639,36 @@ static void reset_dimensions(void)
 		memory_sort_dimensions[i].taken = 0;
 }
 
+bool is_strict_order(const char *order)
+{
+	return order && (*order != '+');
+}
+
 static int __setup_output_field(void)
 {
-	char *tmp, *tok, *str;
-	int ret = 0;
+	char *tmp, *tok, *str, *strp;
+	int ret = -EINVAL;
 
 	if (field_order == NULL)
 		return 0;
 
 	reset_dimensions();
 
-	str = strdup(field_order);
+	strp = str = strdup(field_order);
 	if (str == NULL) {
 		error("Not enough memory to setup output fields");
 		return -ENOMEM;
 	}
 
-	for (tok = strtok_r(str, ", ", &tmp);
+	if (!is_strict_order(field_order))
+		strp++;
+
+	if (!strlen(strp)) {
+		error("Invalid --fields key: `+'");
+		goto out;
+	}
+
+	for (tok = strtok_r(strp, ", ", &tmp);
 			tok; tok = strtok_r(NULL, ", ", &tmp)) {
 		ret = output_field_add(tok);
 		if (ret == -EINVAL) {
@@ -1667,6 +1680,7 @@ static int __setup_output_field(void)
 		}
 	}
 
+out:
 	free(str);
 	return ret;
 }

tools/perf/util/sort.h

@@ -218,4 +218,5 @@ void perf_hpp__set_elide(int idx, bool elide);
 
 int report_parse_ignore_callees_opt(const struct option *opt, const char *arg, int unset);
 
+bool is_strict_order(const char *order);
 #endif	/* __PERF_SORT_H */