[PATCH 08/48] perf dwarf-aux: Factor out __die_get_typename()

From: Namhyung Kim
Date: Wed Oct 11 2023 - 23:52:10 EST


The __die_get_typename() is to get the name of the given DIE in C-style
type name. The difference from the die_get_typename() is that it does
not retrieve the DW_AT_type and use the given DIE directly. This will
be used when users know the type DIE already.

Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/dwarf-aux.c | 38 ++++++++++++++++++++++++++-----------
tools/perf/util/dwarf-aux.h | 3 +++
2 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index 652e6e7368a2..5bb05c84d249 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -1051,32 +1051,28 @@ Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
}

/**
- * die_get_typename - Get the name of given variable DIE
- * @vr_die: a variable DIE
+ * __die_get_typename - Get the name of given type DIE
+ * @type: a type DIE
* @buf: a strbuf for result type name
*
- * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
+ * Get the name of @type_die and stores it to @buf. Return 0 if succeeded.
* and Return -ENOENT if failed to find type name.
* Note that the result will stores typedef name if possible, and stores
* "*(function_type)" if the type is a function pointer.
*/
-int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
+int __die_get_typename(Dwarf_Die *type, struct strbuf *buf)
{
- Dwarf_Die type;
int tag, ret;
const char *tmp = "";

- if (__die_get_real_type(vr_die, &type) == NULL)
- return -ENOENT;
-
- tag = dwarf_tag(&type);
+ tag = dwarf_tag(type);
if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
tmp = "*";
else if (tag == DW_TAG_subroutine_type) {
/* Function pointer */
return strbuf_add(buf, "(function_type)", 15);
} else {
- const char *name = dwarf_diename(&type);
+ const char *name = dwarf_diename(type);

if (tag == DW_TAG_union_type)
tmp = "union ";
@@ -1089,7 +1085,7 @@ int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
/* Write a base name */
return strbuf_addf(buf, "%s%s", tmp, name ?: "");
}
- ret = die_get_typename(&type, buf);
+ ret = die_get_typename(type, buf);
if (ret < 0) {
/* void pointer has no type attribute */
if (tag == DW_TAG_pointer_type && ret == -ENOENT)
@@ -1100,6 +1096,26 @@ int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
return strbuf_addstr(buf, tmp);
}

+/**
+ * die_get_typename - Get the name of given variable DIE
+ * @vr_die: a variable DIE
+ * @buf: a strbuf for result type name
+ *
+ * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
+ * and Return -ENOENT if failed to find type name.
+ * Note that the result will stores typedef name if possible, and stores
+ * "*(function_type)" if the type is a function pointer.
+ */
+int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
+{
+ Dwarf_Die type;
+
+ if (__die_get_real_type(vr_die, &type) == NULL)
+ return -ENOENT;
+
+ return __die_get_typename(&type, buf);
+}
+
/**
* die_get_varname - Get the name and type of given variable DIE
* @vr_die: a variable DIE
diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h
index b6f430730bd1..574405c57d3b 100644
--- a/tools/perf/util/dwarf-aux.h
+++ b/tools/perf/util/dwarf-aux.h
@@ -116,6 +116,9 @@ Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
Dwarf_Die *die_mem);

+/* Get the name of given type DIE */
+int __die_get_typename(Dwarf_Die *type, struct strbuf *buf);
+
/* Get the name of given variable DIE */
int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf);

--
2.42.0.655.g421f12c284-goog