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: Leo Yan <leo.yan@arm.com>
Tested-by: Ian 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: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index dff65d03d30d7029cfa107017c5d73307cf251d4..08b2be257639a35556525f3e956d2af9ee37b66a 100644 (file)
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -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:

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 524a68032bdbebfb21a2caae30f90e75b15a575f..7cf0a39bc200a12f0f18ab73cc7be7b5015fd99d 100644 (file)
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -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)