[PATCH] perf build: filter all combinations of -flto for libbperl

[Holger Hoffstätte]

When building the libperl feature the build uses perl's build flags
(ccopts) but filters out various flags, e.g. for LTO.
While this is conceptually correct, it is insufficient in practice,
since only "-flto=auto" is filterd out. When perl itself is built with
"-flto" this can cause parts of perf being built with LTO and others
without, giving exciting build errors like e.g.:

  ../tools/perf/pmu-events/pmu-events.c:72851:(.text+0xb79): undefined
  reference to `strcmp_cpuid_str' collect2: error: ld returned 1 exit status

Fix this by filtering all matching flag values of -flto{=n,auto,..}.

Signed-off-by: Holger Hoffstätte <holger@xxxxxxxxxxxxxxxxxxxxxx>
---
 tools/perf/Makefile.config | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index a148ca9ef..4f5a40ab8 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -820,7 +820,7 @@ else
   PERL_EMBED_LIBADD = $(call grep-libs,$(PERL_EMBED_LDOPTS))
   PERL_EMBED_CCOPTS = $(shell perl -MExtUtils::Embed -e ccopts 2>/dev/null)
   PERL_EMBED_CCOPTS := $(filter-out -specs=%,$(PERL_EMBED_CCOPTS))
-  PERL_EMBED_CCOPTS := $(filter-out -flto=auto -ffat-lto-objects, $(PERL_EMBED_CCOPTS))
+  PERL_EMBED_CCOPTS := $(filter-out -flto% -ffat-lto-objects, $(PERL_EMBED_CCOPTS))
   PERL_EMBED_LDOPTS := $(filter-out -specs=%,$(PERL_EMBED_LDOPTS))
   FLAGS_PERL_EMBED=$(PERL_EMBED_CCOPTS) $(PERL_EMBED_LDOPTS)
 
--
2.48.1