[PATCH 08/14] perf c2c: add HPP list parsing for function view histograms

[Jiebin Sun]

Add the histogram initialization and column parsing infrastructure:

- c2c_function_hists__init_output(): register output columns
- c2c_function_hists__init_sort(): register sort columns
- function_hpp_list__parse(): parse comma-separated column strings
- c2c_function_hists__init(): initialize function histograms with sort
- c2c_function_hists__reinit(): reinitialize with new output/sort

These functions bridge the function view's custom dimensions with
the perf HPP list infrastructure, enabling dynamic column
configuration during hierarchy construction.

Signed-off-by: Jiebin Sun <jiebin.sun@xxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: James Clark <james.clark@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Falcon <thomas.falcon@xxxxxxxxx>
Reviewed-by: Tianyou Li <tianyou.li@xxxxxxxxx>
Reviewed-by: Wangyang Guo <wangyang.guo@xxxxxxxxx>
---
 tools/perf/ui/browsers/c2c-function.c | 144 +++++++++++++++++++++++++-
 1 file changed, 142 insertions(+), 2 deletions(-)

diff --git a/tools/perf/ui/browsers/c2c-function.c b/tools/perf/ui/browsers/c2c-function.c
index 794a023239ce..c11a81d93c21 100644
--- a/tools/perf/ui/browsers/c2c-function.c
+++ b/tools/perf/ui/browsers/c2c-function.c
@@ -442,7 +442,7 @@ static struct c2c_dimension *function_view_dimensions[] = {
 	NULL,
 };
 
-static __maybe_unused struct c2c_dimension *get_function_dimension(const char *name)
+static struct c2c_dimension *get_function_dimension(const char *name)
 {
 	unsigned int i;
 
@@ -477,7 +477,7 @@ static int64_t c2c_se_collapse(struct perf_hpp_fmt *fmt,
 	return collapse_fn(a, b);
 }
 
-static __maybe_unused struct c2c_fmt *get_function_format(const char *name)
+static struct c2c_fmt *get_function_format(const char *name)
 {
 	struct c2c_dimension *dim = get_function_dimension(name);
 	struct c2c_fmt *c2c_fmt;
@@ -509,6 +509,146 @@ static __maybe_unused struct c2c_fmt *get_function_format(const char *name)
 	return c2c_fmt;
 }
 
+static int
+c2c_function_hists__init_output(struct perf_hpp_list *hpp_list, char *name,
+				struct perf_env *env __maybe_unused)
+{
+	struct c2c_fmt *c2c_fmt = get_function_format(name);
+	int level = 0;
+
+	if (!c2c_fmt) {
+		reset_dimensions();
+		return output_field_add(hpp_list, name, &level);
+	}
+
+	/*
+	 * Mark symbol-backed columns so hists__has(hists, sym) is correct.
+	 * Only dim_symbol_view carries a sort_entry (.se); the function
+	 * view's field strings are fixed and always include symbol_view, so
+	 * this single check is sufficient (unlike the user-configurable
+	 * cacheline view, which must also test dim_iaddr).
+	 */
+	if (c2c_fmt->dim->se == &sort_sym)
+		hpp_list->sym = 1;
+
+	perf_hpp_list__column_register(hpp_list, &c2c_fmt->fmt);
+	return 0;
+}
+
+static int
+c2c_function_hists__init_sort(struct perf_hpp_list *hpp_list, char *name,
+			      struct perf_env *env)
+{
+	struct c2c_fmt *c2c_fmt = get_function_format(name);
+
+	if (!c2c_fmt) {
+		reset_dimensions();
+		return sort_dimension__add(hpp_list, name, /*evlist=*/NULL, env, /*level=*/0);
+	}
+
+	/* Mark symbol-backed sort keys so hists__has(hists, sym) is correct. */
+	if (c2c_fmt->dim->se == &sort_sym)
+		hpp_list->sym = 1;
+
+	perf_hpp_list__register_sort_field(hpp_list, &c2c_fmt->fmt);
+	return 0;
+}
+
+typedef int (*hpp_list_add_fn)(struct perf_hpp_list *hpp_list, char *name,
+			       struct perf_env *env);
+
+static int function_hpp_list__add_tokens(struct perf_hpp_list *hpp_list, char *list,
+					 struct perf_env *env, hpp_list_add_fn add)
+{
+	char *tok, *tmp;
+	int ret;
+
+	if (!list)
+		return 0;
+
+	for (tok = strtok_r(list, ", ", &tmp); tok; tok = strtok_r(NULL, ", ", &tmp)) {
+		ret = add(hpp_list, tok, env);
+		if (ret) {
+			if (ret == -EINVAL || ret == -ESRCH)
+				pr_err("Invalid c2c function-view field: %s", tok);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static int
+function_hpp_list__parse(struct perf_hpp_list *hpp_list,
+			 const char *output_str,
+			 const char *sort_str,
+			 struct perf_env *env)
+{
+	char *output = output_str ? strdup(output_str) : NULL;
+	char *sort   = sort_str   ? strdup(sort_str)   : NULL;
+	int ret = 0;
+
+	if ((output_str && !output) || (sort_str && !sort)) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = function_hpp_list__add_tokens(hpp_list, output, env,
+					    c2c_function_hists__init_output);
+	if (ret)
+		goto out;
+
+	ret = function_hpp_list__add_tokens(hpp_list, sort, env,
+					    c2c_function_hists__init_sort);
+	if (ret)
+		goto out;
+
+	perf_hpp__setup_output_field(hpp_list);
+out:
+	free(output);
+	free(sort);
+	return ret;
+}
+
+static __maybe_unused int
+c2c_function_hists__init(struct c2c_hists *hists,
+			 const char *sort,
+			 int nr_header_lines,
+			 struct perf_env *env)
+{
+	__hists__init(&hists->hists, &hists->list);
+
+	perf_hpp_list__init(&hists->list);
+
+	hists->list.nr_header_lines = nr_header_lines;
+
+	return function_hpp_list__parse(&hists->list, /*output=*/NULL, sort, env);
+}
+
+static __maybe_unused int
+c2c_function_hists__reinit(struct c2c_hists *c2c_hists,
+			   const char *output,
+			   const char *sort,
+			   struct perf_env *env)
+{
+	int nr_header_lines = c2c_hists->list.nr_header_lines;
+
+	perf_hpp__reset_output_field(&c2c_hists->list);
+	INIT_LIST_HEAD(&c2c_hists->list.sorts);
+
+	/* Clear stale state flags so a different output/sort set starts fresh. */
+	c2c_hists->list.need_collapse = 0;
+	c2c_hists->list.parent = 0;
+	c2c_hists->list.sym = 0;
+	c2c_hists->list.dso = 0;
+	c2c_hists->list.socket = 0;
+	c2c_hists->list.thread = 0;
+	c2c_hists->list.comm = 0;
+	c2c_hists->list.comm_nodigit = 0;
+	c2c_hists->list.nr_header_lines = nr_header_lines;
+
+	return function_hpp_list__parse(&c2c_hists->list, output, sort, env);
+}
+
 int perf_c2c__browse_function_view(struct hists *hists __maybe_unused)
 {
 	ui__warning("C2C function view is not implemented yet.\n");
-- 
2.52.0