From 7a838c2fd2ac81e10bedcd912153a74ca662b309 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Mon, 18 Mar 2024 22:50:56 -0700 Subject: perf dwarf-aux: Add die_find_func_rettype() The die_find_func_rettype() is to find a debug entry for the given function name and sets the type information of the return value. By convention, it'd return the pointer to the type die (should be the same as the given mem_die argument) if found, or NULL otherwise. Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Stephane Eranian Link: https://lore.kernel.org/r/20240319055115.4063940-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/dwarf-aux.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'tools/perf/util/dwarf-aux.c') diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 09fd6f1f0ed8..d4ec239c5adb 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -696,6 +696,49 @@ Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, return die_mem; } +static int __die_find_func_rettype_cb(Dwarf_Die *die_mem, void *data) +{ + const char *func_name; + + if (dwarf_tag(die_mem) != DW_TAG_subprogram) + return DIE_FIND_CB_SIBLING; + + func_name = dwarf_diename(die_mem); + if (func_name && !strcmp(func_name, data)) + return DIE_FIND_CB_END; + + return DIE_FIND_CB_SIBLING; +} + +/** + * die_find_func_rettype - Search a return type of function + * @cu_die: a CU DIE + * @name: target function name + * @die_mem: a buffer for result DIE + * + * Search a non-inlined function which matches to @name and stores the + * return type of the function to @die_mem and returns it if found. + * Returns NULL if failed. Note that it doesn't needs to find a + * definition of the function, so it doesn't match with address. + * Most likely, it can find a declaration at the top level. Thus the + * callback function continues to sibling entries only. + */ +Dwarf_Die *die_find_func_rettype(Dwarf_Die *cu_die, const char *name, + Dwarf_Die *die_mem) +{ + Dwarf_Die tmp_die; + + cu_die = die_find_child(cu_die, __die_find_func_rettype_cb, + (void *)name, &tmp_die); + if (!cu_die) + return NULL; + + if (die_get_real_type(&tmp_die, die_mem) == NULL) + return NULL; + + return die_mem; +} + struct __instance_walk_param { void *addr; int (*callback)(Dwarf_Die *, void *); -- cgit v1.2.3