From: Herton R. Krzesinski herton@redhat.com
tools/power/x86/intel-speed-select: fix build failure when using -Wl,--as-needed
Upstream Status: patch submitted to platform-driver-x86/upstream maintainer
Build of intel-speed-select will fail if you run:
$ LDFLAGS="-Wl,--as-needed" /usr/bin/make V=1 ... gcc -O2 -Wall -g -D_GNU_SOURCE -Iinclude -I/usr/include/libnl3 -Wl,--as-needed -lnl-genl-3 -lnl-3 intel-speed-select-in.o -o intel-speed-select /usr/bin/ld: intel-speed-select-in.o: in function `handle_event': (...)/linux/tools/power/x86/intel-speed-select/hfi-events.c:189: undefined reference to `nlmsg_hdr' ...
In this case the problem is that order when linking matters when using the flag -Wl,--as-needed, symbols not used at that point are discarded. So since intel-speed-select-in.o comes after, at that point the libraries/symbols are already discarded and then missing/undefined references are reported.
To fix this, make sure we specify LDFLAGS after the object file.
Signed-off-by: Herton R. Krzesinski herton@redhat.com
diff --git a/tools/power/x86/intel-speed-select/Makefile b/tools/power/x86/intel-speed-select/Makefile index blahblah..blahblah 100644 --- a/tools/power/x86/intel-speed-select/Makefile +++ b/tools/power/x86/intel-speed-select/Makefile @@ -42,7 +42,7 @@ ISST_IN := $(OUTPUT)intel-speed-select-in.o $(ISST_IN): prepare FORCE $(Q)$(MAKE) $(build)=intel-speed-select $(OUTPUT)intel-speed-select: $(ISST_IN) - $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@ + $(QUIET_LINK)$(CC) $(CFLAGS) $< $(LDFLAGS) -o $@
clean: rm -f $(ALL_PROGRAMS)
-- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1736
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