monado/src/xrt/auxiliary/util/u_var.cpp

// Copyright 2019, Collabora, Ltd.
// SPDX-License-Identifier: BSL-1.0
/*!
 * @file
 * @brief  Variable tracking code.
 * @author Jakob Bornecrantz <jakob@collabora.com>
 * @ingroup aux_util
 */

#include "util/u_var.h"
#include "util/u_time.h"
#include "util/u_misc.h"
#include "util/u_debug.h"
#include "util/u_device.h"

#include <string>
#include <sstream>
#include <vector>
#include <unordered_map>


/*
 *
 * Enums, Classes and Defines.
 *
 */


class Var
{
public:
	std::string name;
	u_var_kind kind;
	void *ptr;
};

class Obj
{
public:
	std::string name = {};
	std::vector<Var> vars = {};
};

class Tracker
{
public:
	std::unordered_map<std::string, size_t> counters = {};
	std::unordered_map<ptrdiff_t, Obj> map = {};
	bool on;
	bool tested;

public:
	int
	getNumber(const std::string &name)
	{
		auto s = counters.find(name);
		int count = (s != counters.end() ? s->second : 0) + 1;
		counters[name] = count;

		return count;
	}
};

static class Tracker tracker;


/*
 *
 * Helper functions.
 *
 */

static bool
get_on()
{
	if (tracker.tested) {
		return tracker.on;
	}
	tracker.on = debug_get_bool_option("XRT_TRACK_VARIABLES", false);
	tracker.tested = true;

	return tracker.on;
}

static void
add_var(void *root, void *ptr, u_var_kind kind, const char *c_name)
{
	auto s = tracker.map.find((ptrdiff_t)root);
	if (s == tracker.map.end()) {
		return;
	}

	Var var;
	var.name = std::string(c_name);
	var.kind = kind;
	var.ptr = ptr;

	s->second.vars.push_back(var);
}


/*
 *
 * Exported functions.
 *
 */

extern "C" void
u_var_force_on(void)
{
	tracker.on = true;
	tracker.tested = true;
}

extern "C" void
u_var_add_root(void *root, const char *c_name, bool number)
{
	if (!get_on()) {
		return;
	}

	auto name = std::string(c_name);

	if (number) {
		int count = tracker.getNumber(name);

		std::stringstream ss;
		ss << name << " #" << count;
		name = ss.str();
	}

	auto &obj = tracker.map[(ptrdiff_t)root] = Obj();
	obj.name = name;
}

extern "C" void
u_var_remove_root(void *root)
{
	if (!get_on()) {
		return;
	}

	auto s = tracker.map.find((ptrdiff_t)root);
	if (s == tracker.map.end()) {
		return;
	}

	tracker.map.erase(s);
}

extern "C" void
u_var_visit(u_var_root_cb enter_cb,
            u_var_root_cb exit_cb,
            u_var_elm_cb elem_cb,
            void *priv)
{
	if (!get_on()) {
		return;
	}

	std::vector<Obj *> tmp;
	tmp.reserve(tracker.map.size());

	for (auto &n : tracker.map) {
		tmp.push_back(&n.second);
	}

	for (Obj *obj : tmp) {
		enter_cb(obj->name.c_str(), priv);

		for (auto &var : obj->vars) {
			elem_cb(var.name.c_str(), (u_var_kind)var.kind, var.ptr,
			        priv);
		}

		exit_cb(obj->name.c_str(), priv);
	}
}

#define ADD_FUNC(SUFFIX, TYPE, ENUM)                                           \
	extern "C" void u_var_add_##SUFFIX(void *obj, TYPE *ptr,               \
	                                   const char *c_name)                 \
	{                                                                      \
		if (!get_on()) {                                               \
			return;                                                \
		}                                                              \
		add_var(obj, (void *)ptr, U_VAR_KIND_##ENUM, c_name);          \
	}

U_VAR_ADD_FUNCS()

#undef ADD_FUNC