[PATCH 2/2] perf annotate-data: Add pr_debug_scope()

From: Namhyung Kim
Date: Mon Sep 09 2024 - 17:43:07 EST


The pr_debug_scope() is to print more information about the scope DIE
during the instruction tracking so that it can help finding relevant
debug info and the source code like inlined functions more easily.

$ perf --debug type-profile annotate --data-type
...
-----------------------------------------------------------
find data type for 0(reg0, reg12) at set_task_cpu+0xdd
CU for kernel/sched/core.c (die:0x1268dae)
frame base: cfa=1 fbreg=7
scope: [3/3] (die:12b6d28) [inlined] set_task_rq <<<--- (here)
bb: [9f - dd]
var [9f] reg3 type='struct task_struct*' size=0x8 (die:0x126aff0)
var [9f] reg6 type='unsigned int' size=0x4 (die:0x1268e0d)

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/annotate-data.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index a0ea4e07e57031ff..976abedca09ef547 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -131,6 +131,26 @@ static void pr_debug_location(Dwarf_Die *die, u64 pc, int reg)
}
}

+static void pr_debug_scope(Dwarf_Die *scope_die)
+{
+ int tag;
+
+ if (!debug_type_profile && verbose < 3)
+ return;
+
+ pr_info("(die:%lx) ", (long)dwarf_dieoffset(scope_die));
+
+ tag = dwarf_tag(scope_die);
+ if (tag == DW_TAG_subprogram)
+ pr_info("[function] %s\n", dwarf_diename(scope_die));
+ else if (tag == DW_TAG_inlined_subroutine)
+ pr_info("[inlined] %s\n", dwarf_diename(scope_die));
+ else if (tag == DW_TAG_lexical_block)
+ pr_info("[block]\n");
+ else
+ pr_info("[unknown] tag=%x\n", tag);
+}
+
bool has_reg_type(struct type_state *state, int reg)
{
return (unsigned)reg < ARRAY_SIZE(state->regs);
@@ -1305,8 +1325,9 @@ static enum type_match_result find_data_type_block(struct data_loc_info *dloc,
if (dwarf_ranges(&scopes[i], 0, &base, &start, &end) < 0)
break;

- pr_debug_dtp("scope: [%d/%d] (die:%lx)\n",
- i + 1, nr_scopes, (long)dwarf_dieoffset(&scopes[i]));
+ pr_debug_dtp("scope: [%d/%d] ", i + 1, nr_scopes);
+ pr_debug_scope(&scopes[i]);
+
src_ip = map__objdump_2rip(dloc->ms->map, start);

again:
--
2.46.0.598.g6f2099f65c-goog