perf dwarf-aux: Factor out die_get_typename_from_type()

The die_get_typename_from_type() is to get the name of the given DIE in
C-style type name.

The difference from 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.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index edd9e407bc74e9f972037bf9978e8d317d27b6d6..7aa5fee0da1906a073ac9423305bf26deb569761 100644 (file)
--- 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_from_type - Get the name of given type DIE
+ * @type_die: 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_from_type(Dwarf_Die *type_die, 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_die);
        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_die);
 
                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_die, 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_from_type(&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 0ddf61fd3f8beabf49a185f312b095a000f7015e..4e64caac6df83ea5ba292225894206b450d63222 100644 (file)
--- 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_from_type(Dwarf_Die *type_die, struct strbuf *buf);
+
 /* Get the name of given variable DIE */
 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf);