From 368781025a1133d7f9550358ba421994118608f7 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Mon, 18 Nov 2024 19:17:54 -0800 Subject: [PATCH] perf symbol-elf: Avoid a weak cxx_demangle_sym function cxx_demangle_sym is weak in case demangle-cxx.c replaces the definition in symbol-elf.c. When demangle-cxx.c is built HAVE_CXA_DEMANGLE_SUPPORT is defined, as such the define can be used to avoid a weak symbol. As weak symbols are outside of the C standard their use can lead to strange behaviors, in particular with LTO, as well as causing issues to be hidden at link time. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20241119031754.1021858-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol-elf.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index e398abfd13a09..66fd1249660a3 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -287,8 +287,9 @@ static bool want_demangle(bool is_kernel_sym) * Demangle C++ function signature, typically replaced by demangle-cxx.cpp * version. */ -__weak char *cxx_demangle_sym(const char *str __maybe_unused, bool params __maybe_unused, - bool modifiers __maybe_unused) +#ifndef HAVE_CXA_DEMANGLE_SUPPORT +char *cxx_demangle_sym(const char *str __maybe_unused, bool params __maybe_unused, + bool modifiers __maybe_unused) { #ifdef HAVE_LIBBFD_SUPPORT int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0); @@ -302,6 +303,7 @@ __weak char *cxx_demangle_sym(const char *str __maybe_unused, bool params __mayb return NULL; #endif } +#endif /* !HAVE_CXA_DEMANGLE_SUPPORT */ static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name) {