[PATCH v1 3/6] perf dwarf-aux: Better type matching for stack variables

[Zecheng Li <zecheng@google.com>]

Utilizes the previous is_breg_access_indirect function to determine if
the stack location stores the variable itself or the struct it points
to.

If the DWARF expression shows DW_OP_stack_value without DW_OP_deref, it
indicates the variable value is the reg + offset itself, and the stack
location it points to is the dereferenced type.

Signed-off-by: Zecheng Li <zecheng@google.com>
---
 tools/perf/util/dwarf-aux.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index 814c96ea509f..4039dbd2b8c0 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -1635,6 +1635,14 @@ static int __die_collect_vars_cb(Dwarf_Die *die_mem, void *arg)
 	if (die_get_real_type(die_mem, &type_die) == NULL)
 		return DIE_FIND_CB_SIBLING;
 
+	if ((ops->atom == DW_OP_fbreg || ops->atom == DW_OP_breg7) &&
+	    dwarf_tag(&type_die) == DW_TAG_pointer_type &&
+	    is_breg_access_indirect(ops, nops)) {
+		/* Get the target type of the pointer */
+		if (die_get_real_type(&type_die, &type_die) == NULL)
+			return DIE_FIND_CB_SIBLING;
+	}
+
 	vt = malloc(sizeof(*vt));
 	if (vt == NULL)
 		return DIE_FIND_CB_END;
-- 
2.50.1.470.g6ba607880d-goog