Commit 536661da authored by Leo Yan's avatar Leo Yan Committed by Namhyung Kim
Browse files

perf: build: Only link libebl.a for old libdw 



Since libdw version 0.177, elfutils has merged libebl.a into libdw (see
the commit "libebl: Don't install libebl.a, libebl.h and remove backends
from spec." in the elfutils repository).

As a result, libebl.a does not exist on Debian Bullseye and newer
releases, causing static perf builds to fail on these distributions.

This commit checks the libdw version and only links libebl.a if it
detects that the libdw version is older than 0.177.

Signed-off-by: default avatarLeo Yan <leo.yan@arm.com>
Tested-by: default avatarIan Rogers <irogers@google.com>
Cc: amadio@gentoo.org
Cc: James Clark <james.clark@linaro.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20240717082211.524826-4-leo.yan@arm.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent cffe29d3

tools/build/feature/Makefile

+11 −1
Original line number Diff line number Diff line
@@ -170,7 +170,17 @@ $(OUTPUT)test-libopencsd.bin: 


DWARFLIBS := -ldw

ifeq ($(findstring -static,${LDFLAGS}),-static)

DWARFLIBS += -lelf -lebl -lz -llzma -lbz2

  DWARFLIBS += -lelf -lz -llzma -lbz2



  LIBDW_VERSION := $(shell $(PKG_CONFIG) --modversion libdw)

  LIBDW_VERSION_1 := $(word 1, $(subst ., ,$(LIBDW_VERSION)))

  LIBDW_VERSION_2 := $(word 2, $(subst ., ,$(LIBDW_VERSION)))



  # Elfutils merged libebl.a into libdw.a starting from version 0.177,

  # Link libebl.a only if libdw is older than this version.

  ifeq ($(shell test $(LIBDW_VERSION_2) -lt 177; echo $$?),0)

    DWARFLIBS += -lebl

  endif

endif



$(OUTPUT)test-dwarf.bin:

tools/perf/Makefile.config

+11 −1
Original line number Diff line number Diff line
@@ -152,7 +152,17 @@ ifdef LIBDW_DIR 
endif

DWARFLIBS := -ldw

ifeq ($(findstring -static,${LDFLAGS}),-static)

  DWARFLIBS += -lelf -lebl -ldl -lz -llzma -lbz2

  DWARFLIBS += -lelf -ldl -lz -llzma -lbz2



  LIBDW_VERSION := $(shell $(PKG_CONFIG) --modversion libdw)

  LIBDW_VERSION_1 := $(word 1, $(subst ., ,$(LIBDW_VERSION)))

  LIBDW_VERSION_2 := $(word 2, $(subst ., ,$(LIBDW_VERSION)))



  # Elfutils merged libebl.a into libdw.a starting from version 0.177,

  # Link libebl.a only if libdw is older than this version.

  ifeq ($(shell test $(LIBDW_VERSION_2) -lt 177; echo $$?),0)

    DWARFLIBS += -lebl

  endif

endif

FEATURE_CHECK_CFLAGS-libdw-dwarf-unwind := $(LIBDW_CFLAGS)

FEATURE_CHECK_LDFLAGS-libdw-dwarf-unwind := $(LIBDW_LDFLAGS) $(DWARFLIBS)