path: root/tools/perf/util/annotate-data.c

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Convert sample address to data type using DWARF debug info.
 *
 * Written by Namhyung Kim <namhyung@kernel.org>
 */

#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>

#include "annotate.h"
#include "annotate-data.h"
#include "debuginfo.h"
#include "debug.h"
#include "dso.h"
#include "dwarf-regs.h"
#include "evsel.h"
#include "evlist.h"
#include "map.h"
#include "map_symbol.h"
#include "strbuf.h"
#include "symbol.h"
#include "symbol_conf.h"
#include "thread.h"

#define pr_debug_dtp(fmt, ...)					\
do {								\
	if (debug_type_profile)					\
		pr_info(fmt, ##__VA_ARGS__);			\
	else							\
		pr_debug3(fmt, ##__VA_ARGS__);			\
} while (0)

static void pr_debug_type_name(Dwarf_Die *die)
{
	struct strbuf sb;
	char *str;

	if (!debug_type_profile && verbose < 3)
		return;

	strbuf_init(&sb, 32);
	die_get_typename_from_type(die, &sb);
	str = strbuf_detach(&sb, NULL);
	pr_info(" type=%s (die:%lx)\n", str, (long)dwarf_dieoffset(die));
	free(str);
}

/*
 * Type information in a register, valid when @ok is true.
 * The @caller_saved registers are invalidated after a function call.
 */
struct type_state_reg {
	Dwarf_Die type;
	bool ok;
	bool caller_saved;
};

/* Type information in a stack location, dynamically allocated */
struct type_state_stack {
	struct list_head list;
	Dwarf_Die type;
	int offset;
	int size;
	bool compound;
};

/* FIXME: This should be arch-dependent */
#define TYPE_STATE_MAX_REGS  16

/*
 * State table to maintain type info in each register and stack location.
 * It'll be updated when new variable is allocated or type info is moved
 * to a new location (register or stack).  As it'd be used with the
 * shortest path of basic blocks, it only maintains a single table.
 */
struct type_state {
	/* state of general purpose registers */
	struct type_state_reg regs[TYPE_STATE_MAX_REGS];
	/* state of stack location */
	struct list_head stack_vars;
	/* return value register */
	int ret_reg;
};

static bool has_reg_type(struct type_state *state, int reg)
{
	return (unsigned)reg < ARRAY_SIZE(state->regs);
}

/* These declarations will be remove once they are changed to static */
void init_type_state(struct type_state *state, struct arch *arch __maybe_unused);
void exit_type_state(struct type_state *state);
void update_var_state(struct type_state *state, struct data_loc_info *dloc,
		      u64 addr, u64 insn_offset, struct die_var_type *var_types);
void update_insn_state(struct type_state *state, struct data_loc_info *dloc,
		       Dwarf_Die *cu_die, struct disasm_line *dl);

void init_type_state(struct type_state *state, struct arch *arch)
{
	memset(state, 0, sizeof(*state));
	INIT_LIST_HEAD(&state->stack_vars);

	if (arch__is(arch, "x86")) {
		state->regs[0].caller_saved = true;
		state->regs[1].caller_saved = true;
		state->regs[2].caller_saved = true;
		state->regs[4].caller_saved = true;
		state->regs[5].caller_saved = true;
		state->regs[8].caller_saved = true;
		state->regs[9].caller_saved = true;
		state->regs[10].caller_saved = true;
		state->regs[11].caller_saved = true;
		state->ret_reg = 0;
	}
}

void exit_type_state(struct type_state *state)
{
	struct type_state_stack *stack, *tmp;

	list_for_each_entry_safe(stack, tmp, &state->stack_vars, list) {
		list_del(&stack->list);
		free(stack);
	}
}

/*
 * Compare type name and size to maintain them in a tree.
 * I'm not sure if DWARF would have information of a single type in many
 * different places (compilation units).  If not, it could compare the
 * offset of the type entry in the .debug_info section.
 */
static int data_type_cmp(const void *_key, const struct rb_node *node)
{
	const struct annotated_data_type *key = _key;
	struct annotated_data_type *type;

	type = rb_entry(node, struct annotated_data_type, node);

	if (key->self.size != type->self.size)
		return key->self.size - type->self.size;
	return strcmp(key->self.type_name, type->self.type_name);
}

static bool data_type_less(struct rb_node *node_a, const struct rb_node *node_b)
{
	struct annotated_data_type *a, *b;

	a = rb_entry(node_a, struct annotated_data_type, node);
	b = rb_entry(node_b, struct annotated_data_type, node);

	if (a->self.size != b->self.size)
		return a->self.size < b->self.size;
	return strcmp(a->self.type_name, b->self.type_name) < 0;
}

/* Recursively add new members for struct/union */
static int __add_member_cb(Dwarf_Die *die, void *arg)
{
	struct annotated_member *parent = arg;
	struct annotated_member *member;
	Dwarf_Die member_type, die_mem;
	Dwarf_Word size, loc;
	Dwarf_Attribute attr;
	struct strbuf sb;
	int tag;

	if (dwarf_tag(die) != DW_TAG_member)
		return DIE_FIND_CB_SIBLING;

	member = zalloc(sizeof(*member));
	if (member == NULL)
		return DIE_FIND_CB_END;

	strbuf_init(&sb, 32);
	die_get_typename(die, &sb);