perf unwind: Fix compile error for static cross build
Build failure for static cross-compiling on aarch64, with libunwind-x86
provided:
$ file ./libunwind_for_x86_on_aarch64/lib/libunwind-x86.so.8.0.1
libunwind-x86.so.8.0.1: ELF 64-bit LSB shared object, ARM aarch64,
version 1 (SYSV), dynamically linked, not stripped
$ make LDFLAGS=-static LIBUNWIND_DIR=./libunwind_for_x86_on_aarch64
ARCH=aarch64 CROSS_COMPILE=aarch64-buildroot-linux-gnu-
~/libperf.a(libperf-in.o): In function `find_proc_info':
:(.text+0xae4ac): undefined reference to `_Ux86_dwarf_search_unwind_table'
~/libperf.a(libperf-in.o): In function `_unwind__prepare_access':
:(.text+0xaedd0): undefined reference to `_Ux86_create_addr_space'
:(.text+0xaee24): undefined reference to `_Ux86_set_caching_policy'
~/libperf.a(libperf-in.o): In function `_unwind__flush_access':
:(.text+0xaee98): undefined reference to `_Ux86_flush_cache'
~/libperf.a(libperf-in.o): In function `_unwind__finish_access':
:(.text+0xaef08): undefined reference to `_Ux86_destroy_addr_space'
~/libperf.a(libperf-in.o): In function `get_entries':
:(.text+0xaf148): undefined reference to `_Ux86_init_remote'
:(.text+0xaf184): undefined reference to `_Ux86_get_reg'
:(.text+0xaf1a4): undefined reference to `_Ux86_step'
collect2: error: ld returned 1 exit status
Makefile.perf:350: recipe for target '~/perf' failed
make[1]: *** [~/perf] Error 1
Makefile:68: recipe for target 'all' failed
make: *** [all] Error 2
This is because the remote libunwind library detected is not appended to
EXTLIBS variable, which will be included between 'start-group' and
'end-group' when linking.
The existing variable LIBUNWIND_LIBS is assigned to libs for local
unwind, this patch introduces a new variable EXTLIBS_LIBUNWIND for
storing remote libunwind libraries instead.
Signed-off-by: He Kuang <hekuang@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1465988636-81502-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index 098874b..80018fe 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -365,6 +365,7 @@
$(call detected,CONFIG_LIBUNWIND_X86)
CFLAGS += -DHAVE_LIBUNWIND_X86_SUPPORT
LDFLAGS += -lunwind-x86
+ EXTLIBS_LIBUNWIND += -lunwind-x86
have_libunwind = 1
endif
@@ -372,6 +373,7 @@
$(call detected,CONFIG_LIBUNWIND_AARCH64)
CFLAGS += -DHAVE_LIBUNWIND_AARCH64_SUPPORT
LDFLAGS += -lunwind-aarch64
+ EXTLIBS_LIBUNWIND += -lunwind-aarch64
have_libunwind = 1
$(call feature_check,libunwind-debug-frame-aarch64)
ifneq ($(feature-libunwind-debug-frame-aarch64), 1)
@@ -449,6 +451,7 @@
CFLAGS += -DHAVE_LIBUNWIND_SUPPORT
CFLAGS += $(LIBUNWIND_CFLAGS)
LDFLAGS += $(LIBUNWIND_LDFLAGS)
+ EXTLIBS += $(EXTLIBS_LIBUNWIND)
endif
ifndef NO_LIBAUDIT